Researchers' Goof: Transverse CS Incisions ARE Better in High BMI Women!

EXTRA, EXTRA! 

Researchers messed up the conclusion of earlier cesarean incision study! 

Transverse (side-to-side) incisions really are better after all for high BMI women! 

Vindication! 

Background

For many years OBs were taught that a vertical incision was needed for very "obese" women because the area under a belly flap ("panniculus", sometimes referred to as a "pannus") was hot and moist and therefore prone to infection ─ in other words, an area just waiting to cause wound complications. One OB wrote in 2006:

In general, there is a lot to be said for an incision not buried under the pannus of fat, so that fresh air can help keep the wound dry.

As a result, many OBs were taught that when they did cesareans on high BMI women, vertical (up-down) incisions should be used instead of low transverse (side-to-side, either Pfannenstiel or Joel-Cohen) incisions in order to lower the risk for infection, separations, and other wound complications.

WRONG! Example of incorrect teaching illustration
about vertical incisions and obesity

They meant well, but they were operating from flawed assumptions and outdated teaching. In other words, they hadn't actually studied whether or not vertical was better in high-BMI women, they just assumed it was, based on their biases about fat bodies. As the authors of Alanis 2010 state:

Our results...contradict classic teaching by veteran surgeons and obstetrical texts. It has been written that transverse abdominal incisions made under the pannicular fold exist in “a warm, moist, anaerobic environment associated with impaired bacteriostasis . . .[that] promotes the proliferation of numerous microorganisms, producing a veritable bacteriologic cesspool.” However, we are unable to locate any evidence to support this popular conclusion....

A "veritable bacteriologic cesspool"? What a terrible and disrespectful way for those obstetric texts to describe it. While deep skin folds can sometimes predispose to skin yeast and infections, it doesn't always and surgical incisions should not be based on conditions assumed to exist. Rather, care providers should be aware of the possibility and make decisions based on actual evidence of problems rather than an assumption of pathology.

Vertical Incisions Do Not Improve Outcomes

As noted, cesarean incision choice for very heavy women was usually based on traditional teachings and biased assumptions. When someone actually took the time to research these hypotheses, however, it was found that vertical incisions were no better, and in some studies were actually far more risky.

Let's do a quick review of the medical literature on this topic.

Vertical is More Risky

The Alanis 2010 study discussed above studied women with a BMI over 50. They found better outcomes with transverse incisions:

Vertical abdominal incisions were associated with increased operative time, blood loss, and vertical hysterotomy...Our results also support the use of Pfannenstiel incisions in obese patients with a large panniculus.

D'heureux-Jones 2001 also found that vertical incisions were associated with greater blood loss and poorer outcomes. They recommended a Pfannenstiel incision too.

In some studies the findings were more dramatic. In Wall 2003, vertical incisions presented 12x the risk for wound complications compared to transverse incisions. TWELVE TIMES the risk. That's a tremendous difference.

Thornburg 2012 found that the majority of wound complications (WC) were found in the vertical incision group (45.7% rate in vertical incisions, vs. 11.6% in transverse incisions). That's a very significant difference. They concluded:

In morbidly obese women both infectious and separation type WC are more common in vertical than low transverse incisions; therefore transverse should be preferred.

Vertical is No Improvement

Critics would point out that a number of studies did not find a statistically significant difference between vertical vs. low transverse incisions (Sutton 2016, Vermillion 2000, McLean 2012, Houston and Raynor 2000, Brocato 2013, and Bell 2011). Many researchers cite these studies to argue that there is no difference between incisions and the choice should be completely left to the surgeon's preference.

However, if they read the full text of these studies, the data usually showed a very clear trend towards more complications with vertical incisions. For example, 5 of the 6 above-cited studies found nearly double or more the rate of problems in the vertical incision group, yet the difference did not rise to statistical significance:

• Bell 2011 found wound complications in 14.6% of the vertical incision group vs. 7.6% in the low transverse group
• Vermillion 2000 found a 23% wound infection rate in the vertical group vs. a 6% rate in the low transverse group
• McLean 2012 found a 20% rate of wound separation in the vertical group vs. a 10% rate in the low transverse group
• Sutton 2016 found a 26.3% rate of wound complications in the vertical group vs. 14.8% in the low transverse group 
• Brocato 2013 found 2.7x the risk for wound complications in the vertical group

The problem here is that the number of patients in the vertical incision groups in these studies was extremely small and that is what is confusing the outcome. Bell 2011 had only 41 patients with vertical incisions; Brocato 2013 had only 45; Sutton 2016 had only 57; McLean 2012 had only 25; and Houston and Raynor 2000 had only 15 patients in their vertical comparison groups. Basically, the studies showing no significant difference had too few vertical incisions to be rigorously compared. 

The fact that the differences didn't rise to statistical significance doesn't mean that vertical incisions were just as safe; it just means that these studies were simply underpowered to show statistical significance between the groups. 

Summary

Larger studies do need to be done, but the majority of the evidence we have so far suggests that vertical incisions perform no better and often perform worse in obese women. Low transverse incisions are usually associated with better outcomes. 

Bottom line, vertical incisions are associated with increased rates of wound complications, blood loss, and infections in obese women, even very obese women, as we have written about extensively before. In addition, vertical incisions are far more scarring and challenging to a woman's self-esteem and should ideally be avoided on that basis alone. It's also worth noting that although the best incision for each woman's unique anatomy and situation must be judged on an individual basis, low transverse incisions have been used successfully even in women of 400-500 pounds without poor outcomes.

Vertical Skin = Vertical Uterine Incisions

Image from swcare.net

Another problem is that several of these studies (Bell 2011, Alanis 2010, Sutton 2016) have also shown that when vertical skin incisions are done, they result in a higher rate of vertical uterine incisions (hysterotomies). Bell 2011 found that nearly 2/3 of all vertical skin incisions in obese women resulted in a vertical uterine incision as well.

A vertical uterine incision results in a riskier surgery, with more blood loss, a more difficult recovery, and a higher rate of uterine rupture in future pregnancies. In most OB practices, it limits a woman's future delivery choices to automatic repeat cesareans, which may have tremendous long-term health implications for the mother due to increased placental abnormalities and intraoperative injuries. The Alanis 2010 authors noted:

Vertical abdominal incisions were associated with vertical hysterotomy in our study, usually a result of inadequate access to the lower uterine segment. When the incision extends into the contractile portion of the uterus, a vertical hysterotomy has a profound impact on future pregnancy. Therefore, it is important to incorporate practices, like transverse abdominal incisions, that facilitate low uterine incisions.

Doing a vertical incision routinely and without pressing need in high BMI women subjects them to more risk and potentially limits their future reproductive choices. As a result, one reviewer concluded that in obese women:

Low transverse skin incisions and transverse uterine incisions are definitely superior and must be the first option.

In recent years, more and more OBs began to use low transverse incisions in women of size. In fact, today the vast majority of high BMI women ─ even very high BMI women ─ who have cesareans have low transverse incisions. This is encouraging progress.

Still, many OBs cling to their teaching and use a vertical incision at a higher rate for obese women, especially "morbidly obese" and "super obese" women.

A 2016 survey of OBs revealed that while 84% preferred a transverse incision for obese women, 16% still preferred other incisions (usually vertical).

McLean 2012 found that 11% of high-BMI women were still being subjected to the riskier vertical incisions; Marrs 2014 (a very large, multi-region, multi-center study; see below) found that vertical incisions were used in a whopping 19% of high BMI women.

Between these documents, that's a vertical incision in about 1 out of every 5-10 cesareans done in obese women. So while progress has been made, vertical incisions are still distressingly common, and they are still putting the well-being of women of size at risk.

But What About That 2014 Study?

Some doctors have pointed to the Marrs 2014 study to justify continuing with vertical incisions. This was the one study that seemed to disprove the idea that transverse was better. (See the first abstract below, full text can be found here.)

This was a secondary analysis of the MFMU registry, which examined data from cesareans in 19 different regional hospitals. This analysis looked at incision complications after cesarean in women with a BMI of 40 or more. Since it was the largest study of its kind in obese women (597 vertical incisions, 2603 transverse incisions), its conclusions were assumed to be far more powerful and definitive.

In the study, wound complications were found in 1.7% of women with transverse incisions vs. 4.2% of women with vertical incisions. In other words, more than double the rate of problems were found with vertical incisions. Simple conclusion to be drawn, right? Not quite.

In its univariate (one variable) analysis, transverse was shown to be the safer incision. But in its multivariate (multiple variable) analysis, the opposite was found ─ vertical seemed better. This conclusion was trumpeted far and wide because now there was research ammo to keep justifying the use of vertical incisions in high-BMI women.

However, a re-analysis of the data shows that their conclusion was wrong and transverse was better after all. Turns out they used the wrong figures in their multivariate analysis and so got the wrong conclusion. Instead of vertical being the better incision, it was actually transverse that had the best outcomes. The authors issued a retraction in July of 2017 and stated:

The original publication reported that univariate analysis showed that a vertical skin incision in obese women undergoing Cesarean delivery was associated with a higher odds ratio for wound complications than a transverse skin incision. Multivariable analyses showed a reversal of the association (i.e. the odds of wound complications were lower in women with a vertical skin incision). However, there was an error in the way the variable was entered in the logistic analysis. Re-analysis with the correct coding of the variable indicates that a transverse skin incision is associated with decreased odds of wound complication compared to a vertical skin incision.

Well, bravo that they finally published a retraction to the previous study and a corrected abstract...3 years after the fact. (I have published the abstracts to both below for comparison.)

At least they actually printed a retraction and admitted their error. Usually these are just glossed over. But I'm irritated because the damage has been done. How many OBs have gotten the wrong impression and won't see the retraction? How many young doctors have been erroneously taught that vertical incisions were superior for high BMI women?

When you search online, the original manuscript with its erroneous conclusions still pops up without any corrections, and is still being cited by some doctors as evidence that a vertical incision is just as good or better.

How many high-BMI women have had the more dangerous vertical incision in the meantime and how many will continue being subjected to it because of the error in that original study? How many medical schools and textbooks will continue teaching that vertical incisions are better?

Grrrrrrrr. Mistakes happen, but this is a mistake with long-lasting implications for larger women. I can't believe they were sloppy enough to make this mistake in the first place and then not discover it for three years. I also question whether they are doing enough to reach out to correct the mistaken teaching and care practices that are in place because of this egregious error. If it's not addressed aggressively, incorrect teachings and practices will remain in place, and that could have a lot of negative health implications for women of size.

Conclusion

Low transverse cesarean scar in a high BMI woman;
these are usually minimally noticeable after a few years

A vertical skin incision on a high BMI woman has far more noticeable
scarring and potential impact on her self-esteem

The cesarean rate in obese women is unconscionably high. Some cesareans are needed of course, but many cesareans in high BMI women are planned pre-labor cesareans, and many labor cesareans could probably be avoided with more patience, fewer inductions, a more lenient surgical threshold, and different management in labor.

But the fact of the matter is that around half or more of all obese mothers in many areas of the U.S. are being subjected to cesareans. The rate of wound complications increases with BMI in a dose-respondent manner, so the question of how to lower complications in obese women is extremely pressing.

Proper choice of cesarean incision is one key way to reduce complications in obese women. Thankfully, most OBs recognize that a low transverse is the best incision in high BMI women, and use it most of the time.

However, some OBs continue to insist that vertical is better, especially as BMI increases. One 2014 study found only a 2% rate of vertical incisions in women with BMIs between 30 and 40, but this increased to more than 15% in women with a BMI over 50. The fact that the Marrs MFMU study found that vertical incisions were used in 19% (nearly 1 in 5 cesareans of obese women) in women with a BMI over 40 is quite alarming. These high rates are risking the health and well-being of women of size.

Furthermore, OBs have even been known to use a vertical incision to discourage their "morbidly obese" patients from having more children. This is appalling example of weight stigma. Here is one woman's story:

When she came in to discuss my surgery, the OB sat down and asked me if I wanted my tubes tied while she was in there. I was shocked and told her no, that this was my first child, and I didn't want to make decisions like that at the moment. And she countered with a speech that boiled down to 'You are too fat to have any more children, you shouldn't even be having this one, and if I had anything to do with it, you wouldn't be.'...[Afterwards] the hateful OB informed me that the kind of incision that they made in my uterus will make it incredibly dangerous for me to attempt another pregnancy...a subsequent pregnancy could cause the uterus to rupture and I would die horribly from a hemorrhage.

Granted, there are sometimes circumstances which compel the use of a vertical incision. An extremely large belly makes it harder to locate anatomical landmarks; sometimes the panniculus is so large it is impossible to place an incision beneath it; sometimes there is an active skin infection present in the folds; sometimes other factors like fetal or placental position make a different incision safer. In those situations, there are other incision options, including a vertical or a higher transverse (Joel-Cohen) incision. However, this mother had none of these considerations. The incision seems to have been chosen purely to punish the mother and to strongly discourage further children despite her refusal of sterilization.

Whatever the reasons, there is no justification for such a high rate of vertical incisions still being used in heavy women. Medical schools and educational materials need to stop teaching that a vertical incision is the incision of choice for high BMI women.

Research CLEARLY shows that a vertical incision performs no better than a transverse one in obese women and in most research, is actually associated with worse outcomes. NO study now shows a better outcome with vertical incisions. 

The bottom line is that incision choice for each woman of size must be evaluated on its individual circumstances, but a low transverse incision should be the default choice in nearly all high BMI women. As one OB said in a conference presentation to colleagues:

The bottom line is that vertical incisions should not be used in obese patients...Vertical incisions are being used less and less in these patients, but just don't do it.

References

Original Article

Am J Obstet Gynecol. 2014 Apr;210(4):319. doi: 10.1016/j.ajog.2014.01.018. Epub 2014 Feb 20. The relationship between primary cesarean delivery skin incision type and wound complications in women with morbid obesity. Marrs CC, Moussa HN, Sibai BM, Blackwell SC. Full text here.

OBJECTIVE: We sought to evaluate the relationship between skin incision, transverse or vertical, and the development of wound complications in women with morbid obesity requiring primary cesarean delivery (CD). STUDY DESIGN: Morbidly obese women (body mass index ≥40 kg/m(2)) undergoing primary CD at ≥24 weeks' gestation were studied in a secondary analysis of a multicenter registry. Clinical characteristics and outcomes were compared between women who had transverse vs vertical skin incision. The primary outcome was composite wound complication (infection, seroma, hematoma, evisceration, fascial dehiscence) and composite adverse maternal outcome (transfusion, hysterectomy, organ injury, coagulopathy, thromboembolic event, pulmonary edema, death). Multivariable logistic regression analyses were performed to adjust for confounding factors. RESULTS: In all, 3200 women were studied: 2603 (81%) had a transverse incision and 597 (19%) had a vertical incision. Vertical skin incision was associated with lower risk for wound complications (adjusted odds ratio, 0.32; 95% confidence interval, 0.17-0.62; P < .001) but not with composite adverse maternal outcome (adjusted odds ratio, 0.72; 95% confidence interval, 0.41-1.25; P = .24). CONCLUSION: In morbidly obese women undergoing a primary CD, vertical skin incision was associated with a lower wound complication rate. Due to the selection bias associated with utilization of skin incision type and the observational nature of this study, a randomized controlled trial is necessary to answer this clinical question.

Retraction and Revised Conclusion

Am J Obstet Gynecol. 2017 Jul;217(1):85. doi: 10.1016/j.ajog.2017.06.002. Removal notice to The relationship between primary cesarean delivery skin incision type and wound complications in women with morbid obesity: Am J Obstet Gynecol 2014;210:319.e1-4. Marrs CC, Moussa HN, Sibai BM, Blackwell SC. PMID: 28648694

This article has been removed: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been removed at the request of the Editors-in-Chief and Authors. The original publication reported that univariate analysis showed that a vertical skin incision in obese women undergoing Cesarean delivery was associated with a higher odds ratio for wound complications than a transverse skin incision. Multivariable analyses showed a reversal of the association (i.e. the odds of wound complications were lower in women with a vertical skin incision). However, there was an error in the way the variable was entered in the logistic analysis. Re-analysis with the correct coding of the variable indicates that a transverse skin incision is associated with decreased odds of wound complication compared to a vertical skin incision.

Studies Which Show Poorer Outcome with Vertical Incisions in Obese Women

• D'heureux-Jones 2001 - http://www.sciencedirect.com/science/article/pii/S0029784401012959
• Wall 2003 - https://www.ncbi.nlm.nih.gov/pubmed/14672469
• Alanis 2010 - https://www.ncbi.nlm.nih.gov/pubmed/20678746
• Thornburg 2012 - https://www.ncbi.nlm.nih.gov/pubmed/22233403
• Marrs 2017 - see above abstract, https://www.ncbi.nlm.nih.gov/pubmed/28648694

Small Studies Which Show No Statistically Significant Difference

• Vermillion 2000 - https://www.ncbi.nlm.nih.gov/pubmed/10831993 
• Houston and Raynor 2000 - https://www.ncbi.nlm.nih.gov/pubmed/10819819
• McLean 2012 - https://www.ncbi.nlm.nih.gov/pubmed/22105439
• Bell 2012 - https://www.ncbi.nlm.nih.gov/pubmed/20832161
• Brocato 2013 - https://www.ncbi.nlm.nih.gov/pubmed/24349784
• Sutton 2016 - https://www.ncbi.nlm.nih.gov/pubmed/26692204 

My Previous Writings on Skin Incisions in High BMI Cesareans

• http://wellroundedmama.blogspot.com/2011/11/cesarean-incision-choice-in-women-of.html - Overview of previous research around vertical vs. transverse incisions  
• http://wellroundedmama.blogspot.com/2011/12/misleading-wording-vertical-vs-low.html  - how the wording in the abstract of of McLean 2012 was misleading and made it seem like vertical incisions performed just as well, which did not match the authors' conclusions that transverse is preferred

Staples vs. Sutures During Cesareans in High BMI Women

Women of size have higher rates of cesareans in many studies. Many of them are probably preventable but the fact remains that high-BMI women have a high rate of cesareans.

One of the problems with this is that "obese" women are at increased risk for infection and wound complications after a cesarean, and this leads to a great deal of morbidity and healthcare costs.

What can be done to improve outcomes? Past research has strongly suggested that closing the subcutaneous fat layer and avoiding a surgical drain reduces the rates of infection in high-BMI women. Higher doses of antibiotics also seem to be helpful, though the best dosage is still being debated. Using low transverse incisions instead of vertical incisions whenever possible probably also lowers the risk for complications.

Now, new studies seem to suggest that taking the time to suture the wound closed may result in less infection than using staples to close the wound. 

Doctors don't always like to do this because suturing takes longer. And suturing a woman with a lot of abdominal fat is more challenging as well. So most often, staples are used to close a cesarean, especially in women of size. But is this a good idea?

Mackeen 2015 performed a meta-analysis of studies and found that using sutures cut the risk for wound complications in half compared to staples. This risk reduction persisted even when data was stratified by obesity levels.

Zaki 2016 studied sutures vs. staples specifically in obese women. They found:

Women with staples had higher wound complications compared with sutures (22.0% versus 9.7%) with a 2.27 unadjusted relative risk (RR) (95% confidence interval (CI), 1.7 to 3.0) and 1.78 adjusted RR (95% CI, 1.27 to 2.49) after controlling for confounders in the final analysis, including vertical skin incisions. 

Further studies done specifically on high-BMI women should be done to confirm these findings, but the findings so far seem pretty clear. Using a subcuticular suture to close the incision seems to lessen the risk for wound complications compared to staples.

This is important news because research shows that as BMI increases, doctors are less inclined to use sutures. 

In other words, without intending to, doctors may actually be unnecessarily increasing the risk for wound complications after cesarean in women of size.

Conclusion

I'm glad to see that more research is FINALLY being done on how to lessen the rate of complications in women of size who undergo a cesarean.

For years, doctors simply made assumptions about what they thought would improve cesarean outcomes in obese women ─ but they didn't test their assumptions. Once they started testing the assumptions, they found a few surprises.

Doctors have traditionally been more inclined to use vertical incisions in high-BMI women. They did this because they thought that vertical incisions would lessen the risk for infection by avoiding the area underneath the belly (pannus). They were wrong; most research shows that vertical incisions actually increase the risk for wound complications in obese women.

They thought surgical drains would allow fluids to exit and thereby decrease the chances for wound separations and infections. Yet some research seems to suggest that surgical drains actually increase the risk for problems.

They assumed that the standard antibiotic dosage for all women was sufficient for high-BMI women too. Yet research shows that standard dosages probably do not provide adequate coverage to prevent infections.

When a cesarean is truly needed, it's a wonderful and life-saving thing to have available. Although cesareans carry more risks for obese women, there are important things that doctors can do to improve outcomes in high-BMI women when a cesarean is truly necessary. This list may now include suturing instead of using staples to close the wound, even if it takes slightly longer to accomplish.

However, let's not lose sight of the fact that the most important step that doctors can take to improve outcomes in obese women is to only do cesareans when they are truly needed. 


References

J Perinatol. 2016 Oct;36(10):819-22. doi: 10.1038/jp.2016.89. Epub 2016 Jun 2. Wound complications in obese women after cesarean: a comparison of staples versus subcuticular suture. Zaki MN, Truong M, Pyra M, Kominiarek MA, Irwin T. PMID: 27253895

OBJECTIVE: To compare wound complications between staples versus subcuticular suture for skin closure in obese women (body mass index (BMI)⩾30 kg m(-2)) after cesarean delivery (CD). STUDY DESIGN: We conducted a retrospective cohort study to compare wound complications between staples and subcuticular suture closure in women, with a prepregnancy BMI⩾30 kg m(-2) after CD between 2006 and 2011 at an inner-city teaching hospital. Wound complication was defined as a composite of wound disruption (hematoma or seroma) or infection diagnosed up to 6 weeks postpartum. Variables collected include age, parity, prior CDs, prior abdominal surgeries, incision type, chorioamnionitis, maternal comorbidities (hypertension, diabetes) and gestational age. RESULTS: Of the 1147 women included in the study, women with staple closure were older and had higher BMIs (40.6±9.3 versus 36.1±5.4) and were more likely to be multiparous, have a prior CD, diabetes and hypertension compared with women with subcuticular suture. The overall occurrence of wound complications was 15.5% (178/1147). Women with staples had higher wound complications compared with sutures (22.0% versus 9.7%) with a 2.27 unadjusted relative risk (RR) (95% confidence interval (CI), 1.7 to 3.0) and 1.78 adjusted RR (95% CI, 1.27 to 2.49) after controlling for confounders in the final analysis, including vertical skin incisions. CONCLUSIONS: In obese women, skin closure with staples at the time of CD is associated with a higher rate of wound complications compared with subcuticular suture. Skin closure with subcuticular suture over staples should be considered in obese women undergoing a CD regardless of skin incision type.

Am J Obstet Gynecol. 2015 May;212(5):621.e1-10. doi: 10.1016/j.ajog.2014.12.020. Epub 2014 Dec 19. Suture versus staples for skin closure after cesarean: a metaanalysis. Mackeen AD, Schuster M, Berghella V. PMID: 25530592

OBJECTIVE: We sought to perform a metaanalysis to synthesize randomized clinical trials of cesarean skin closure by subcuticular absorbable suture vs metal staples for the outcomes of wound complications, pain perception, patient satisfaction, cosmesis, and operating time...RESULTS: Twelve randomized trials with data for the primary outcome on 3112 women were identified. Women whose incisions were closed with suture were significantly less likely to have wound complications than those closed with staples (risk ratio, 0.49; 95% confidence interval [CI], 0.28-0.87). This difference remained significant even when wound complications were stratified by obesity. The decrease in wound complications was largely due to the lower incidence of wound separations in those closed with suture (risk ratio, 0.29; 95% CI, 0.20-0.43), as there were no significant differences in infection, hematoma, seroma, or readmission. There were also no significant differences in pain perception, patient satisfaction, and cosmetic assessments between the groups. Operating time was approximately 7 minutes longer in those closed with suture (95% CI, 3.10-11.31). CONCLUSION: For patients undergoing cesarean, closure of the transverse skin incision with suture significantly decreases wound morbidity, specifically wound separation, without significant differences in pain, patient satisfaction, or cosmesis. Suture placement does take 7 minutes longer than staples.

Am J Perinatol. 2014 Apr;31(4):299-304. doi: 10.1055/s-0033-1348402. Epub 2013 Jun 13. Maternal obesity and risk of postcesarean wound complications. Conner SN, Verticchio JC, Tuuli MG, Odibo AO, Macones GA, Cahill AG. PMID: 23765707

OBJECTIVE: To estimate the effect of increasing severity of obesity on postcesarean wound complications and surgical characteristics. STUDY DESIGN: We performed a retrospective cohort study of consecutive cesarean deliveries at a tertiary care facility from 2004 to 2008. Four comparison groups were defined by body mass index (BMI; kg/cm2): < 30 (n = 728), 30 to 39.9 (n = 1,087), 40 to 49.9 (n = 428), or ≥ 50 (n = 201). The primary outcome was wound complication, defined as wound disruption or infection within 6 weeks postoperatively. Surgical characteristics were compared between groups including administration of preoperative antibiotics, type of skin incision, estimated blood loss (EBL), operative time, and type of skin closure. RESULTS: Of the 2,444 women with complete follow-up data, 266 (10.9%) developed a wound complication. Compared with nonobese women (6.6%), increasing BMI was associated with an increased risk of wound complications: BMI 30.0 to 39.9, 9.2%, adjusted odds ratio (aOR) 1.4 (95% confidence interval [CI] 0.99 to 2.0); BMI 40.0 to 49.9, 16.8%, aOR 2.6 (95% CI 1.7 to 3.8); BMI ≥ 50, 22.9%, aOR 3.0 (95% CI 1.9 to 4.9). Increasing BMI was also associated with increased rates of midline vertical incision, longer operative time, higher EBL, and lower rates of subcuticular skin closure. CONCLUSION: A dose-response relationship exists between increasing BMI and risk of postcesarean wound complications. Increasing obesity also significantly influences operative outcomes.

Decreasing Cesarean Wound Complications in Obese Women

Best Pract Res Clin Obstet Gynaecol. 2015 Apr;29(3):406-14. doi: 10.1016/j.bpobgyn.2014.08.009. Epub 2014 Oct 16. Obesity and the challenges of caesarean delivery: prevention and management of wound complications. Ayres-de-Campos D1. PMID: 25457856

Caesarean section in obese patients is associated with an increased risk of surgical wound complications, including haematoma, seroma, abscess and dehiscence. This review focusses on the available strategies to decrease wound complications in this population, and on the clinical management of these situations. Appropriate dose of prophylactic antibiotics, closure of the subcutaneous tissue, and avoidance of subcutaneous drains reduce the incidence of wound complications associated with caesarean section in obese patients. For treatment of superficial wound infection associated with dehiscence, there are data from general surgery patients to suggest that the use of vacuum-assisted devices leads to faster healing and that surgical reclosure is preferable to healing by secondary intention, when there are no signs of ongoing infection. There is a need for stronger evidence regarding the prevention and management of wound complications for caesarean section in obese women.

  

Honey for Cesarean Wound Healing?

We've discussed honey for wound healing before, and specifically for cesarean wound healing.

We talked about the mechanics of how honey (medical grade honey, not supermarket honey) might help healing and what studies there were on the topic.

As one review notes:

Honey has anti-oxidant, anti-bacterial and anti-inflammatory properties. It can be used as a wound dressing to promote rapid and improved healing. These effects are due to honey's anti-bacterial action, secondary to its high acidity, osmotic effect, anti-oxidant content and hydrogen peroxide content. The use of honey leads to improved wound healing in acute cases, pain relief in burn patients and decreased inflammatory response in such patients...There is biological plausibility.

Mixed Results

While honey has "biological plausibility" as a healing agent, results from use of medical grade honey have been encouraging in some situations and discouraging in others. Results were not very good for venous ulcers, for example, but on some wounds there are better results.

A recent Cochrane review found decidedly mixed results, depending on what type of wound was being studied, and cautioned against its routine use until more data is available. So it's hard to know just how useful medical grade honey really is, and how much is just hype.

The problem is that much of the honey-based research is sponsored by the companies that make medical-grade honey, so the results are at high risk for bias.

Bottom line.....better data is needed. But given the positive results in some studies and its relatively low cost, why haven't there been more well-controlled studies done by independent groups by now?

Medical-Grade Honey for Cesarean Healing

Sadly, there's not a lot of data on using honey for cesarean wound healing. There are a couple of older studies done in third-world countries, but they had small data sets and uncontrolled conditions. As a result, using medical honey on a cesarean wound has not been been embraced in Western countries.

Now there's a new study on the use of honey for abdominal wound healing after cesarean. The data set is still very small and still from a third-world country, but at least the study design is randomized and blinded. The results from this study were encouraging.

This doesn't prove honey is a healing agent of choice for cesarean wounds, but it certainly points to the need for bigger and better studies to further examine the question. 

I would particularly like to see medical-grade honey investigated in the treatment of cesarean wound infections of "obese" women (who are substantially more at-risk for wound infection than other women).

About 15-30% of high-BMI women will experience a wound infection after a cesarean, and sometimes these infections last for months. Wound infections like this can be devastating to a new mother, can interfere with breastfeeding, and are costly to treat.

Many cesarean wound infections in obese women can likely be lowered by using more appropriate dosages of antibiotics, but medical grade honey might give another weapon in the arsenal against infections in this group of women.

Of course, the best treatment is prevention of the cesareans in the first place whenever possible, which is why the 40-80% cesarean rate in "morbidly" and "super obese" women is so completely unacceptable.

But sometimes cesareans truly are necessary. When cesareans do occur in this group of women, more tools are needed to help prevent or treat the wound infections that will result in some of them.

Medical-grade honey might be yet another tool in the toolbox for this situation. And it's past time for Western medicine to investigate this possibility more thoroughly.


Reference

Oman Med J. 2014 Jul;29(4):255-9. doi: 10.5001/omj.2014.68. The effect of honey gel on abdominal wound healing in cesarean section: a triple blind randomized clinical trial. Nikpour M1, Shirvani MA2, Azadbakht M3, Zanjani R4, Mousavi E5. PMID: 25170405

OBJECTIVE: To assess whether honey can accelerate the wound healing in women undergoing cesarean section. METHODS: This was a triple blinded randomized prospective clinical trial. Women with cesarean section were randomly designated as drug (37 cases) and placebo (38 cases) groups. The drug group received local honey gel 25% while the placebo group received similar free-honey gel on abdominal cesarean incision twice a day for 14 days. REEDA scale (Redness, Edema, Ecchymosis, Discharge and Approximation of wound edges) was used to assess wound healing. RESULTS: The mean REEDA was 2.27 ± 2.46 and 3.91 ± 2.74 (p=0.008) on the 7(th) day and 0.47 ± 0.84 and 1.59± 1.95 (p=0.002) on the 14(th) day for the drug and placebo groups, respectively. Redness, edema and hematoma in the drug group were significantly lower on the 7(th) and 14(th) days. CONCLUSION: Honey was effective in healing the cesarean section incision. Using topical honey is suggested as a natural product with rare side effects in order to reduce the complications of cesarean wounds.

Supraumbilical Incisions Associated with Greater Risk in Obese Women

Here is yet another study showing that vertical incisions (supraumbilical, in this case) results in suboptimal outcomes, even in "morbidly obese" women.

To review, doctors have assumed for many years that vertical (up-down) incisions would lessen the risk of infection and wound complications in very fat women by avoiding an incision in the moist area underneath the belly. This was based more on assumptions than on real evidence, but it was taught as a medical truth for many years.

However, a number of recent studies have shown poorer outcomes with vertical incisions, showing the need to re-evaluate this medical teaching. Yet some doctors still believe and promote that a vertical incision is necessary in high-BMI women.

New Study

This study reaffirms (yet again) that vertical incisions do NOT improve outcome. 

It found that women who had a supraumbilical vertical incision experienced more blood loss, longer operating times, and nearly 25 times the risk of a classical cesarean, which is a far riskier uterine incision with long-lasting implications for future pregnancies.

In addition, the study showed that doing a vertical incision did NOT reduce the risk for infection or other wound complication. In fact, although the difference did not rise to statistical significance (probably because of the small sample size), there was a clear trend towards more wound complications in the group with the vertical incision (19% vs. 8% in the horizontal incision group, a 2.7x risk after adjusting for confounders).

Discussion of Cesarean Incision Research

Many providers are catching on that vertical incisions generally result in poorer outcomes, even in the most obese women. I'm happy to report that there seem to be fewer women of size being pushed into classical cesareans purely because of weight, and that more educational institutions are teaching that low transverse (side-to-side) incisions are preferable in most cases, regardless of the woman's BMI.

Sadly, though, there are still some stubborn hold outs who insist that very obese women "need" a vertical incision, and some educational institutions and materials are still promoting this approach.

And it's important to note that even though fewer providers are using vertical incisions in obese women now, about 1 in 10 to 1 in 15 obese women having a cesarean are still being subjected to a vertical incision.

This flies in the face of the fact that the vast majority of research clearly indicates that vertical incisions carry more complications and often result in the risky classical uterine incision that has tremendous short- and long-term health implications for the mother. 

Furthermore, research on vertical versus horizontal incisions in non-maternity abdominal incisions confirms the general superiority of horizontal incisions.

Some recent researchers are resisting the move towards low transverse incisions in women of size. They have claimed that the evidence is not yet conclusive on whether vertical or low-transverse incisions are better. They point out that most study samples are not randomized and do not rise to the "gold standard" research that is most desirable, and that some studies have not found a statistical difference in wound complications between incision types.

While the call for gold standard research is a legitimate concern, there have been enough studies that have found worse outcomes with vertical incisions that they should be curtailed while we wait for the results of a randomized controlled study. (There is a randomized study currently being conducted but it won't be finished for several years yet; if we wait until this study is finished and published before changing policy, many more high-BMI women will likely suffer major wound complications and associated morbidity by being subjected to vertical incisions in the interim.)

It's true that a few studies (like the one discussed today) have not found a statistical difference in wound complications between vertical and low-transverse incisions. However, if you read the full studies more closely, all found a strong trend towards worse outcomes in the vertical group. These differences simply did not rise to statistical significance because of the small sample sizes involved, not because results were truly equivalent.

It's also important to point out that not a single study has found improved outcomes with vertical incisions. If vertical incisions really resulted in superior outcomes, that trend would be clear, and it most definitely has not been. Instead, the trend is markedly in the other direction and only fails to be clear because of the small sample sizes in some studies.

Clearly, more research needs to be done. But in the meantime, considering the strong trend in the existing research, vertical incisions should be reserved only for times when it is truly medically indicated (certain placental presentations, certain fetal positions, extremely emergent situations, etc.).

Bottom line, vertical incisions should NOT be done routinely simply because a woman has a high BMI.

It's time for all the educational institutions and clinicians to acknowledge this and adjust their teaching and practices accordingly.


Reference

J Pregnancy. 2013;2013:890296. doi: 10.1155/2013/890296. Epub 2013 Nov 20. The effect of cesarean delivery skin incision approach in morbidly obese women on the rate of classical hysterotomy. Brocato BE1, Thorpe EM Jr1, Gomez LM1, Wan JY2, Mari G1. PMID: 24349784 (Free full text can be found here.)

OBJECTIVE: To assess the risk of classical hysterotomy and surgical morbidity among women with a body mass index (BMI) greater than 40 kg/m(2) who underwent a supraumbilical incision at the time of cesarean delivery. METHODS: We conducted a retrospective cohort study in women having a BMI greater than 40 kg/m(2) who underwent a cesarean delivery of a live, singleton pregnancy from 2007 to 2011 at a single tertiary care institution. Intraoperative and postoperative outcomes were compared between patients undergoing supraumbilical vertical (cohort, n = 45) or Pfannenstiel (controls, n = 90) skin incisions. RESULTS: Women undergoing supraumbilical incisions had a higher risk of classical hysterotomy (OR, 24.6; 95% CI, 9.0-66.8), surgical drain placement (OR, 6.5; 95% CI, 2.6-16.2), estimated blood loss greater than 1 liter (OR, 3.4; 95% CI, 1.4-8.4), and longer operative time (97 ± 38 minutes versus 68 ± 30 minutes; P < .001) when compared to subjects with Pfannenstiel incisions (controls). There was no difference in the risk of wound complication between women undergoing supraumbilical or Pfannenstiel incisions (OR, 2.7; 95% CI, 0.9-8.0). CONCLUSION: In women with a BMI above 40 kg/m(2), supraumbilical incision at the time of cesarean delivery is associated with a greater risk of classical hysterotomy and operative morbidity.

Cesarean Wound Complications: A Reason to Avoid CS in Women of Size

image from caesarean.org.uk 

It's no secret that surgery is harder in "obese" people and there is more risk for infection and other wound complications.

This is why doctors generally discourage surgery in fat people.

However, somehow this caution against routine surgery in fat people doesn't seem to apply when it comes to pregnancy, where some care providers routinely just schedule an automatic cesarean section in women with a BMI over 40 (and often under that).

Even when a routine cesarean is not scheduled, research shows clearly that care providers have a lower surgical threshold for "obese" women, and manage labor in this group in a way that leads to more cesareans.

The bottom line here is that cesarean sections in obese women are extremely common, even though the surgery is harder and more risky in this group. And that means many women of size deal with cesarean wound complications. That's a tough way to start motherhood and can interfere with breastfeeding and bonding.

Now, a new study confirms that cesarean wound complications rise as BMI rises. This is not really a surprise, but the study still had lessons to teach the obstetric community ─ if it would just be open to hearing them.

Results of the Study

In the study, the rate of wound complications (infections, wound disruptions) rose in a dose-response relationship to BMI. The wound complication rates were:

• BMI <30    -            6.6%
• BMI 30-40 -            9.2%
• BMI 40-50 -          16.8%
• BMI 50+    -          22.9%

That means that nearly 1 out of 6 women with a BMI of 40 or more and nearly 1 in 4 women with a BMI of 50 or more developed a significant wound complication.

Not good. But there are studies where the wound complication rate in women of this size is even higher. Alanis 2010 found that nearly 1 in 3 women with a BMI of 50 or more developed cesarean wound complications.

A good reason to stop doing so many cesareans in women of size, right?

Too bad that's not the lesson most care providers will take from this. Many care providers' only answer to the high rate of cesarean wound complications is that obese women need to lose weight before pregnancy. Period.

Never mind that the cesarean rate is outrageously high in obese women and could probably be lowered.  Never mind that many care providers routinely schedule automatic cesareans for women with a high BMI, most of which are questionable.

Never mind that very few "morbidly obese" people lose weight to a so-called normal BMI, let alone maintain that loss for any length of time. Never mind that trying to lose weight yet again often leads to weight cycling, which is a strong risk factor for weight gain in the long run.

And never mind that many of these cesarean wound complications might be preventable with different techniques and protocols more appropriate to these women's size.

Nope, the answer to everything is to tell women to just lose weight, rather than to lower the cesarean rate in obese women or to study how to improve outcome in this group independent of losing weight.

Deep down, some care providers seem to believe that fat women deserve whatever complication happens and don't feel very motivated to study how to improve outcomes in high-BMI women. Others may feel complications are simply a logical consequence of adiposity and not very preventable.

Yet how do they know these outcomes aren't preventable if they don't even study it?

It just stumps me how care providers can have about a 50% c-section rate (or more) in very obese women and have done so little study on how to improve outcomes in this group.

But be that as it may, there are still things to be learned from this study.

Lessons from the Study

Here are a couple of lessons that care providers should be taking from this study.

Lesson #1 - Unless there is a compelling medical reason to use a vertical incision, STOP using it in women of size.

In the study, surgeons did more vertical incisions on women as obesity increased. Yet vertical incisions are associated with increased rates of wound complications and infections in obese women in a number of studies.

It's rarely truly necessary to use a vertical incision, even in extremely obese women, and it increases the risk for poor outcomes. Low transverse incisions have been used successfully even in women of 400-500 pounds without poor outcomes.

If care providers want to lessen wound complications in obese women, then they need stop doing so many vertical incisions. Yet some are still promoting the idea that vertical incisions are the incision of choice in fat people. Wrong.

Lesson #2 - Start studying ways to improve post-cesarean outcomes in women of size. 

Considering that half or more of obese women undergo cesareans in some areas of the U.S. (!!!), why haven't there been studies trying to examine how to reduce complications in these women?

For example, I'd love to see some large randomized trials on optimizing cesarean techniques for women of size, like what dose of antibiotics is best for morbidly obese women. Recent research shows that current antibiotic dosage is not adequate for many high-BMI women but very little research has been done on the efficacy and safety of increasing antibiotic dosage in this group.

Research on other surgical procedures suggests that many obese people benefit from extended antibiotic regimens, more frequent dosing, use of extended-spectrum drugs, and topical infusions of antibiotics during surgery. It may take a combination of increased doses and other techniques to truly bring down the rates of surgical site infections; when will there be research to discover what is the best antibiotic dosage and regimen for "morbidly obese" women who have had a cesarean?

In addition, care providers should study whether changes in surgical technique could improve outcomes in this group. There have been some trials on whether or not to suture the adipose layer and whether or not to use drains, but more research on this is needed to confirm what previous studies seem to show. Currently, the research seems to suggest that there is a strong benefit from suturing the adipose layer, but that surgical drains may do more harm than good. Let's do more research to answer this question definitively.

Closure materials and methods may be relevant as well. The wound complications study we are discussing mentions that more obese women were closed using staples instead of subcuticular stitches, yet some recent research suggests that staples may predispose to more wound complications. Non-absorbable versus absorbable stitches may make a difference, too. Stitching takes longer than staples, especially in heavier women, but doing it (and using optimal materials) might be another way to lower the risk for problems.

Examine wound-healing treatments too, like wound vacs and medicinal honey, to see which ones work the best for speeding surgical healing for those obese women who experience wound complications.

The important thing is to study these options more closely in this population and then develop and implement Best Practice Recommendations for them, instead of just shrugging our shoulders and lamenting the rate of problems.

Lesson #3 - The biggest lesson here is that cesareans should NOT be done without good reason in women of size.  

When are care providers going to study how to lower the cesarean rate in this group?

There are many studies documenting and bemoaning a high c-section rate in obese women. Yet rarely do they study whether this rate can be changed with different management.  

Care providers are not powerless to lower the c-section rate; many studies have shown that cesarean rates can be lowered safely when attention is focused on the problem.  But not one study has been done to try and see if the cesarean rate in obese women could be lowered.

The easiest way to do this would be to stop the common practice of planned cesareans. In one recent study, a third of very obese women had primary cesareans without labor. If one out of every three or four of these women then develop serious wound complications (not to mention the downstream complications of placental issues in future pregnancies), that's a LOT of morbidity resulting from cesareans that are questionable in the first place.

Once you reduce non-labor cesareans, start studying ways to lower the labor cesarean rate in this group. Many care providers believe that a high cesarean rate in labor is inevitable in very fat women, yet studies show very different rates. This suggests that there is room for change.

For example, one study of "super obese" (BMI 50+) women from the U.K. showed half the cesarean rate of a similar group in Kentucky and another group in Canada.

Cesarean rates in "super obese" women are often nearly 50-60% in some areas of North America, yet this U.K. study had a cesarean rate of 30% in women of the same size. This shows that the cesarean rate in labor could be far less in "super obese" women, and is potentially modifiable.

Most very obese women rarely see midwives and this may also be part of why they have high cesarean rates, since hospitals with a high rate of births attended by midwives tend to have lower cesarean rates.  Obese women are induced at very high rates, and this may be a strong part of the cesarean rate in this group as well.

There are many possibilities for trying to lower the cesarean rate in obese women, but at this point, no one is even trying to do so.

If you want to lower the high rate of cesarean wound complications in obese women, the most effective way to do so is to lower the number of cesareans done in this group.

Summary 

This study shows that cesarean wound complications tend to rise as BMI rises. This is hardly ground-breaking research.

However, it would be far more groundbreaking if researchers turned their attention to proactively preventing more of these complications.

If 1 in 4 (or more) high-BMI women are experiencing significant wound complications, then something needs to change instead of just accepting this occurrence as inevitable.

Unfortunately, most care providers would look at this data and say that it means we need yet another anti-obesity campaign to scare women into losing weight before pregnancy, despite the stacks of evidence showing how difficult and how unlikely this is to happen.

Make no mistake, I'm all for encouraging people to be as healthy as possible, but the data clearly shows that massive, sustained weight loss is very unlikely in most fat people. Putting all your prevention eggs in the weight loss basket means that there will be a lot of egg on the faces of the care providers involved.

Instead, what providers should be doing is recognizing the opportunities that underlie this data.  We don't have to have a 1 in 4 wound complication rate in obese women.  We can change that outcome. Let's start studying how.

The first and most important step, of course, is to stop DOING so many cesareans in women of size.  That includes stopping the all-too-common practice of routine planned cesareans in obese women. It means questioning whether a cesarean in a woman of size is truly indicated on a case-by-case basis, instead of blithely accepting that a high cesarean rate "goes with the territory" in this group. It also means doing large-group research to discover ways to lower the labor cesarean rate in women of size (hint: stop doing so many inductions and expand midwifery access for obese women) and demanding accountability from care providers with extremely c-section high rates in this group.

The second step is to stop doing vertical incisions on obese women unless truly medically needed. This will lower the rate of wound complications and will make postpartum recovery easier, not to mention being less disfiguring to the mother. In addition, stop teaching that vertical incisions are preferable in women of size, when the evidence clearly indicates that they are not. Although most care providers use low transverse incisions in their obese patients, some stubbornly keep doing and even promoting vertical incisions in this group. This takes a big toll on the women who are subjected to them. It's past time for this outdated practice to be retired.

The third step is to research surgical technique and protocols to lessen the risk for wound complications when a cesarean truly is needed in women of size. Study whether surgical drains are helpful or harmful in obese women, research optimal antibiotic dosing and regimens, examine whether closure technique and materials need adjusting, and subject wound healing techniques to closer scrutiny to see which are most optimal in this group.

Although wound healing is always going to be more challenging in obese women, a high rate of cesarean wound complications is not inevitable. Instead of bemoaning the situation, find ways to improve outcomes in this group without having to tie it to unlikely goal of weight reduction.

Bottom line...stop doing so many cesareans on women of size.  And when they are truly needed, have some quality research in place to show how the risk for wound complications can be lessened in this group.


Reference

Am J Perinatol. 2013 Jun 13. [Epub ahead of print] Maternal Obesity and Risk of Postcesarean Wound Complications. Conner SN, Verticchio JC, Tuuli MG, Odibo AO, Macones GA, Cahill AG. PMID: 23765707

Objective: To estimate the effect of increasing severity of obesity on postcesarean wound complications and surgical characteristics. 

Study Design: We performed a retrospective cohort study of consecutive cesarean deliveries at a tertiary care facility from 2004 to 2008. Four comparison groups were defined by body mass index (BMI; kg/cm2): < 30 (n = 728), 30 to 39.9 (n = 1,087), 40 to 49.9 (n = 428), or ≥50 (n = 201). The primary outcome was wound complication, defined as wound disruption or infection within 6 weeks postoperatively. Surgical characteristics were compared between groups including administration of preoperative antibiotics, type of skin incision, estimated blood loss (EBL), operative time, and type of skin closure. 

Results: Of the 2,444 women with complete follow-up data, 266 (10.9%) developed a wound complication. Compared with nonobese women (6.6%), increasing BMI was associated with an increased risk of wound complications: BMI 30.0 to 39.9, 9.2%, adjusted odds ratio (aOR) 1.4 (95% confidence interval [CI] 0.99 to 2.0); BMI 40.0 to 49.9, 16.8%, aOR 2.6 (95% CI 1.7 to 3.8); BMI ≥50, 22.9%, aOR 3.0 (95% CI 1.9 to 4.9). Increasing BMI was also associated with increased rates of midline vertical incision, longer operative time, higher EBL, and lower rates of subcuticular skin closure. 

Conclusion: A dose-response relationship exists between increasing BMI and risk of postcesarean wound complications. Increasing obesity also significantly influences operative outcomes.

Cesarean Incisions in Women of Size: Supraumbilical?

Illustration used with permission © Anatomy by Design, Inc.

We previously discussed cesarean incision choice in women of size ─ specifically, the choice of vertical (up-down) incisions vs. low transverse (side-to-side) incisions.

The gist of those posts is that for years many doctors were erroneously taught that a vertical (up-down) incision was best in very fat women.  They were taught that the area under a fat woman's belly (called an "apron", "pannus" or "panniculus") was far too prone to infection, so it was best not to do an incision there.  Instead, many were taught to do a vertical skin incision, which often turned into a vertical or "classical" incision on the uterus as well.

High-BMI women were told that this vertical incision would lessen their risk for complications like wound infection, wound separation, bleeding, etc., but when researchers finally got around to actually studying this, they found the opposite ─ that outcomes were not improved with vertical incisions, that vertical incisions actually worsen outcomes in many cases.  Furthermore, classical uterine incisions have poorer outcomes, both short-term and long-term, and therefore should not be undertaken lightly.

Despite the evidence that vertical incisions do not improve outcome and may worsen it, many doctors are still promoting the idea that an incision under the belly is far too prone to infection to use.  As recently as 2006, one OB-GYN wrote, "In general, there is a lot to be said for an incision not buried under the pannus of fat, so that fresh air can help keep the wound dry."  And the illustration above is from a 2009 article, which also highlights the supposed dangers of an incision under the belly.

Now some doctors are promoting another choice for cesarean incisions in very heavy women ─ one done above or near the belly button. This is called a "supraumbilical" (above the belly button) incision.  This incision is not new, but is gaining new traction among some OBs. While not extremely common, it is being promoted by some doctors as beneficial in supersized women.  But is it?

So today, let's talk about supraumbilical incisions and their pros and cons.

Trigger Alert - This post discusses the difficulties associated with surgery on the bellies of very fat women.  Some graphic details are included, and the tone of the research cited is often quite judgmental.  Therefore, readers who might find this triggering may wish to skip this post.

Supraumbilical vs. Low Transverse Incisions

The difficulty in doing abdominal surgery on very heavy women is the barrier that a large amount of belly fat presents.  If you cut through the middle of the belly, you are going through the thickest part of the belly, which takes longer, increases the risk for excessive bleeding, and inhibits healing because of decreased vascularization of adipose (fat) tissue.

Thus, surgeons have come up with 2 approaches to avoiding incisions in the fattest part of the belly. The first is a low transverse incision, under the belly, and the second is a supraumbilical incision, above or near the belly button (umbilicus).

The low transverse incision (usually Pfannenstiel or Joel-Cohen) has repeatedly been shown to have superior outcomes to other incisions, even in obese women.  However, doing it in women with very large bellies is not easy.

Low-transverse incision made under the belly
by pulling back the panniculus

In the picture just above, the woman's overhanging belly is pulled back via a strap or tape towards the mother's head.  This exposes the area under the panniculus (which tends to be thinner) and a low transverse (side-to-side) incision is made there.

Again, many doctors have erroneously been taught that this area is hot, moist, and "a veritable bacteriologic cesspool" (yes, actual quote from the medical literature) and thus highly prone to infection.  In addition, an assistant is sometimes required to hold back the belly during a cesarean, and this can be very physically tiring.  Therefore, some doctors have sought an alternative.

The supraumbilical incision has become popular in some obstetric circles as a possible alternative, especially for women with extremely large or "droopy" bellies.

The $64,000 question is whether this improves outcomes over low-transverse incisions.

Types of Supraumbilical Incisions

In most women, a supraumbilical skin incision translates to a vertical (up-and-down) incision in the skin above the belly button, as in the picture below (repeated from the top of the post). This then is usually accompanied by a vertical/classical incision in the uterus underneath.



This differs from the usual classical incision, which is a vertical (up-down) incision also , but done from the belly button down to the pubic bone.  This also involves a uterine incision in the upper segment of the uterus.

The main difference between a supraumbilical incision and the usual classical incision is that the supraumbilical is done above the belly button, not below it.

Sometimes a supraumbilical incision is done side-to-side (transverse above the belly button, on the upper uterine segment), a picture of which can be found here. 

However, in a few women with extremely voluminous and droopy bellies, a skin incision above the belly button translates into an incision into the lower segment of the uterus, as in the picture below.

A supraumbilical skin incision,
but with a low uterine incision

[Sorry for the blurry image above; it is from a medical study and is very small. When enlarged, the text becomes blurry.  The words from L to R are "panniculus", "umbilicus", "projection of the pubic symphysis", "abdominal and low uterine segment incisions".]

In other words, in a few women the belly droops down low enough that it pulls down the alignment of the skin over the uterus, so that the skin area above the belly button sits near the the pubic bone (pubic symphysis), over the lower uterine segment instead.  In such a case, a supraumbilical skin incision can translate into a low transverse uterine incision. Since lower-uterine segment (LUS) incisions have fewer complications, this combines the advantages of easier surgical access with a supraumbilical skin incision and the better long-term prognosis of a LUS uterine incision.

However, most of the time, a supraumbilical skin incision means a uterine incision in the upper uterus, which carries more risks, both short-term and long-term.  

Patterson (2002) and Bakhshi (2010) compared outcomes in women who had classical incisions vs. low transverse incisions.  They found that women with classical incisions had more infections, more hysterectomies, more blood transfusions, longer operating time, and more intensive care admissions.  They also had far more uterine scar separations in future pregnancies.  Therefore the decision to do a supraumbilical incision potentially has far-reaching implications.

Some doctors are far too quick to resort to supraumbilical incisions on "morbidly obese" women, and at BMIs that don't truly require it. Since most supraumbilical incisions result in classical uterine incisions, doctors are putting these women at considerable risk, whether it's because they don't want to deal with the mechanical challenges of a low transverse incision, or because they have erroneously been taught that the risk of infection is higher in an under-the-belly incision.

Cosmetic Considerations

Another problem with supraumbilical incision that scarring that accompanies it.

The negative cosmetic and psychological impact of a giant scar above the belly button in women of size must not be underestimated.

Research on supraumbilical incisions never considers this, as if the surgeons believe that the bellies of women of size are already so repugnant that a giant scar in the middle of the belly is of no consequence.  Yet, as with midline vertical incisions, the potential psychological impact of such a disfiguring scar is tremendous.

I have a friend who had multiple cesareans ─ not because she wanted them but because of the fat-phobic ignorance of her first OB.  That OB had been taught that a low transverse incision was too prone to infection in obese women, so her first cesarean was supraumbilical, with a classical vertical incision on the uterus. Her next two cesareans were low-transverse repeat cesareans with a different OB, since she could not find anyone who would  let her try a VBAC with a prior classical incision. Her subsequent OB was very frank that the decision to do a supraumbilical incision was totally unnecessary in her first cesarean, and very sympathetic to her frustration that this arbitrary decision by the first OB had totally taken away all her options in subsequent pregnancies.

Even as time lessened the scarring, she found the supraumbilical scar far more disfiguring than her low transverse scars.  She wrote:

I had a supraumbilical incision, so I have this huge scar about 1 inch wide in the middle of my abdomen.  Not very pretty.... 

As far as cosmetics go, my LT [low transverse] incision is so far down it starts right above my pubic hairline...so it's barely noticeable, and in an area no one else but [my husband] would see.

The scarring from a supraumbilical incision is noticeable, and it does matter to women of size.  Just because their bellies are large doesn't mean that cosmetic considerations are irrelevant.

Oh, and those subsequent low-transverse incisions my friend had?  No infection issues at all, despite what her first OB was taught.  But the psychological impact of that first, supraumbilical scar has stayed with her for years. And the doctor's choice for a supraumbilical incision denied her any choices in her future births, any chance at a VBAC, and exposed her to the risks of classical cesareans, not to mention the risks of the subsequent repeat cesareans that were mandatory with the doctors in her area.

The cosmetic considerations of such a disfiguring scar in such an easily-seen place should not be underestimated when making the decision about incisions in women of size.  Just because a woman is obese doesn't mean these cosmetic considerations are moot.  Nor should the limitations supraumbilical incisions place on future pregnancies be shrugged off lightly.

Supraumbilical Incisions: A Summary

To be fair, supraumbilical incisions have certain advantages from the surgeon's point of view. They offer easier accessibility to the uterus in women with very large amounts of belly fat.  They are also less demanding on the O.R. staff, who often have to "pull back" and hold the pannus away from the lower uterine segment, which can be difficult and tiring. One can appreciate and sympathize with the technical demands of doing abdominal surgery in heavy women.

However, given the downsides of supraumbilical scars, this is not enough.  Supraumbilical incisions need to be shown to result in clinically superior outcomes, and they have not been.  Although researchers expected that supraumbilical incisions would improve outcome in very fat women, the data showed that they did NOT actually improve outcome.  Outcomes were actually similar among women with low transverse incisions and supraumbilical incisions.

Again, most of these supraumbilical incisions result in uterine incisions in the upper uterine segment, which is MUCH more risky, much  harder to recover from, and which has profound implications for any future pregnancies.  It also essentially ensures the woman must always have repeat cesareans in the future. Furthermore, they leave a large, very disfiguring scar on the upper abdomen of women after the surgery is over.  A low transverse skin incision is also scarring, but is far less obvious and far less disfiguring in most cases.

The whole premise of doing supraumbilical incisions was to improve outcome for obese women. If they do not improve outcome while simultaneously placing the woman at extra risk and being quite disfiguring, there is no good reason for doing supraumbilical incisions in most cases.

Yes, supraumbilical incisions are easier to perform and are easier on the operating room staff.  Yes, low transverse incisions are harder in supersized women and can present many technical and physical challenges.  However, the bottom line is that the surgeon's convenience should take a back seat to the best interests of the mother and baby (and future babies).

Of course, there may occasionally be situations where such an incision might be useful, such as in a woman with extreme obesity, a woman with an extremely large and droopy belly, or a woman with a complicated placenta previa (low-lying placenta).  No one is saying that supraumbilical incisions should be absolutely banned, only that they should be kept for very rare cases where they are truly needed.  They should not be done routinely, even in high-BMI women.

Fortunately, most cesareans being done today are low-transverse incisions, even in women of size.  However, there are some doctors who use classical or supraumbilical incisions as a routine alternative to low transverse incisions in "morbidly obese" women, and their threshold for using it is far too low in some cases.  The mean BMI for a supraumbilical incision in the Tixier study below was 47, which is near my own BMI.  Many women of this BMI (including me) and a lot larger have had low transverse incisions with no problems, so any routine use of supraumbilical incisions in this size is highly questionable.

A supraumbilical incision can be a useful tool under certain extreme circumstances.  It's worth documenting the technique for that reason. Even so, it must be pointed out that supraumbilical incisions do not improve outcome over low transverse incisions, and they should never be used routinely or because they are easier for the O.R. staff.

An incision like this has far too many implications for maternal health and future pregnancies. Only under special, extreme circumstances should a supraumbilical incision be utilized.


*Images from "Delivery and postpartum concerns in the obese gravida" (Phillips, Obmanagement, Feb 2009), Gunatiake and Perlow 2011, and the Tixier 2009 study below.

References

Supraumbilical Incisions

Houston MC and Raynor BD. Postoperative morbidity in the morbidly obese parturient woman: supraumbilical and low transverse abdominal approaches. American Journal of Obstetrics and Gynecology 2000 May;182(5):1033-35. PMID: 10819819

OBJECTIVE: Our purpose was to determine the differences in postoperative morbidity in obese women who had a supraumbilical or a Pfannenstiel incision at cesarean delivery. STUDY DESIGN: A case-control retrospective review was conducted of all patients who were at greater than 150% ideal body weight when undergoing cesarean delivery between 1989 and 1995 by means of either a supraumbilical or a Pfannenstiel incision. Patients were excluded if medical records were unavailable. A total of 15 women who had a supraumbilical incision and 54 who had a low transverse incision were included in the analysis. Antenatal complications were examined, as were age, weight, and training level of the surgeon. Postoperative complications were then compared. RESULTS: The groups were similar in age and antepartum complications. However, mean weight and percentage of ideal body weight in the supraumbilical group were both higher (P less than .00001 and P less than .0001, respectively), with the supraumbilical group 83 lb heavier on average. No significant differences were seen in any postoperative complication. CONCLUSION: Postoperative morbidity in morbidly obese women undergoing cesarean delivery does not differ between a supraumbilical approach and the low transverse abdominal incision.

Tixier H et al. Cesarean section in morbidly obese women: supra or subumbilical transverse incision? Acta Obstetrecia et Gynecologica Scandanavica 2009;88(9):1049-52. PMID: 19639463

The obstetrician is more and more frequently faced with the decision to perform a cesarean section in obese women. We describe a technique of supra or subumbilical transverse cesarean section (depending on the height of the projection of the upper edge of the pubic symphysis) specifically designed for morbidly obese women with a voluminous panniculus. We evaluated feasibility and associated morbidity in a retrospective descriptive series of 18 patients operated between 2003 and 2008. We assessed the quality of access to the lower uterine segment and facility to extract the fetus. The mean body mass index was 47.7 kg/m(2) (range 40.1-60.8). The incision was subumbilical in 13 women (72.2%) and supraumbilical in 27.7%. With this technique, the exposition, the section of the lower uterine segment, and extraction of the baby are simple. It can be easily generalized and quickly learnt.

J Reprod Med. 2007 Mar;52(3):231-4. Cesarean birth in the morbidly obese woman: a report of 3 cases. Porreco RP, et al.  PMID: 17465294

BACKGROUND: Primary and repeat cesarean births are a frequent occurrence among morbidly obese women. Technical difficulties encountered in caring for these patients, coupled with physiologic differences, affect their operative management. CASES: Three morbidly obese women (190-296 kg, body mass index 56.7-93.6) had cesarean births utilizing a supraumbilical incision and internal retention abdominal wall closures. Alternative anesthetic management was required in 2 patients. Bariatric operative and postoperative equipment was required in each case, and varying thromboprophylaxis strategies were employed. CONCLUSION: Careful planning along with appropriate specialty consultation is required for a safe and successful cesarean birth in the morbidly obese woman.

J Obstet Gynaecol. 2002 Nov;22(6):691. 'Classical' caesarean section at or near term in the morbidly obese obstetric patient.  Nicholson SC, Brown AD, MacPherson HM, Liston WA.   PMID: 12554273  [no abstract available]

"Morbidly obese obstetric patients undergoing caesarean section with a large, protruding panniculus present major technical problems to the obstetrician and anaesthetist and significant operative risk to themselves...It is our practice to perform a high transverse abdominal incision, avoiding the subpannicular fold, thereby reducing the risks of wound infection, necrosis, and dehiscence."   

Kmom summary: Case report of 2 cesareans in morbidly obese women (BMI 58 and 70) with a large panniculus.  Surgeons used a high transverse abdominal incision just below the umbilicus.  The lower uterine segment could not be accessed, so they did a classical fundal uterine incision.  They briefly discussed alternatives to this subumbilical transverse incision, including supraumbilical midline incisions and a panniculectomy (surgical removal of the pannus, which can be associated with many complications) before the cesarean.  They completely dismissed the fact that low transverse incisions have been used successfully on women of this size in the past.

Successful Low Transverse Incisions Used on Supersized Women

Obstet Gynecol. 1978 Apr;51(4):509-10. Cesarean section in the massively obese. Ahern JK, Goodlin RC.   PMID: 662236

"The case histories of 4 massively obese patients who underwent cesarean section are summarized. In all, a Pfannenstiel incision was made beneath the patient's huge panniculus, and a lower segment cesarean section was easily accomplished. There were no postoperative wound infections and all of the women had an essentially benign postoperative course." 

Kmom Summary: Case report of 4 women who each weighed more than 400 lbs. and were delivered via a Pfannenstiel cesarean incision underneath the panniculus.  The surgeons were surprised by the ease of delivery ("no more difficult than in women of only half their weight") and felt that the Pfannenstiel/low transverse incision was the reason for their good outcomes. They disagreed with earlier statements by other authors that "only a novice" makes a transverse incision under the panniculus.

Anaesth Intensive Care. 1999 Apr;27(2):216-9. Anaesthesia for LSCS in a morbidly obese patient. Patel J. PMID: 10212725

Kmom Summary: The management of a morbidly obese parturient with a body mass index of 88 is reported. She developed asthma during the pregnancy. Lumbar epidural anaesthesia was successfully used for an elective caesarean section and tubal ligation.  Special note: A lower-uterine segment Pfannestiel incision was used with NO problems or infection in this woman who was nearly 500 lbs. at the time of her cesarean.

N Am J Med Sci. 2012 Jan;4(1):13-8. Cesarean section in morbidly obese parturients: practical implications and complications. Machado LS. PMID: 22393542

...A Medline search was conducted to review the recent relevant articles in english literature on cesarean section in morbidly obese women. The types of incisions and techniques used during cesarean delivery, intra-operative and postpartum complications, anesthetic and logistical issues, maternal morbidity and mortality were reviewed. Morbidly obese women with a body mass index (BMI >40 kg/m(2) are at increased risk of pregnancy complications and a significantly increased rate of cesarean delivery. Low transverse skin incisions and transverse uterine incisions are definitely superior and must be the first option. Closure of the subcutaneous layer is recommended, but the placement of subcutaneous drains remains controversial. Thromboprophylaxis adjusted to body weight and prophylactic antibiotics help in reducing postpartum morbidity....

Retracting the Panniculus for a Low Transverse Incision

J Am Coll Surg. 2001 Oct;193(4):458-61. Caesarean delivery and celiotomy using panniculus retraction in the morbidly obese patient. Thornton YS.   PMID: 11584977   [no abstract available]

Kmom Summary: Case series of successful low transverse incisions in 47 morbidly obese pregnant women and 9 obese gynecologic patients, all of whom weighed between 208 to 500 lbs, with BMIs between 33.8 to 76.4.  Shows in pictures their technique of using cloth tape across the abdomen and from both sides of the lower abdomen to the upper body (described as the "suspender" method) to pull the panniculus towards the head and expose the lower uterine segment so that a classical vertical or supraumbilical approach was not needed.  They noted that this technique used materials on hand at most hospitals (instead of specialized bariatric instruments), gave "excellent exposure of the operative field without piercing the skin," and took away the need for a surgical assistant to constantly hold back the panniculus during the operation. Despite the incision being in the "moist subpannicular fold" so vilified in the literature, there were NO wound infections or dehiscences, even in the most obese patients.

MedGenMed. 2006 Feb 21;8(1):52. Preventing a surgical complication during cesarean delivery in a morbidly obese patient: a simple apparatus to retract the abdominal panniculus. Viegas CM, Viegas OA.   PMID: 16915182   Free full text here (includes illustrations not for the faint of heart).

"This case report highlights an unusual intraoperative complication that has medical and medico-legal implications. A simple apparatus designed to retract the panniculus of an obese patient might reduce complications when performing abdominal surgery in such cases." 

Kmom Summary: Case report of a cesarean performed on a morbidly obese mother (BMI 54) who was also a very heavy smoker (which impedes healing).  They induced labor by breaking her waters, but as a result, the baby presented in a brow position and developed fetal distress during the prolonged induced labor.  An urgent cesarean was performed under general anesthesia.  A medical student was drafted to manually hold back the large panniculus during the cesarean.  Her incision healed up well afterwards, but the patient developed severe ulcers at the pressure points where the medical student held back her belly (picture available at the full text site; it's very graphic, be warned).  In response to this case, the authors invented a special apparatus to hold back the panniculus in heavy women during cesareans, using a bar over the surgical bed, chains hooked to the bar and then connected to a Doyen's Retractor, which is used to hold back the panniculus. A picture of this device is available in the article.  The authors state they've used it successfully with no problems since, but do not present any data on this claim.  

Risks of Classical Cesareans 

Obstet Gynecol. 2002 Oct;100(4):633-7. Maternal and perinatal morbidity associated with classic and inverted T cesarean incisions. Patterson LS, O'Connell CM, Baskett TF.  PMID: 12383525

OBJECTIVE: To estimate the maternal and perinatal morbidity associated with cesarean delivery involving the upper uterine segment compared with that of low transverse cesarean delivery. METHODS: A 19-year review of a perinatal database and the relevant charts was used to determine the maternal and perinatal morbidity associated with low transverse cesarean, classic cesarean, and inverted "T" cesarean deliveries. RESULTS:Over the 19 years, 1980-1998, there were 19,726 cesarean deliveries: low transverse cesarean, 19,422 (98.5%); classic cesarean, 221 (1.1%); and inverted T cesarean, 83 (0.4%). As a proportion of all cesarean deliveries, the rates of low transverse cesarean and classic cesarean have remained stable, whereas the rate of inverted T cesarean has risen from 0.2% to 0.9%. Maternal morbidity (puerperal infection, blood transfusion, hysterectomy, intensive care unit admission, death) and perinatal morbidity (stillborn fetus, neonatal death, 5 minute Apgar less than 7, intensive care) were significantly higher in classic cesarean compared to low transverse cesarean. Some maternal morbidity (puerperal infection, blood transfusion) and perinatal morbidity (5 minute Apgar less than 7, intensive care) were also significantly higher for inverted T cesarean compared to low transverse cesarean. CONCLUSION: Classic cesarean section has a higher maternal and perinatal morbidity than inverted T cesarean and much higher than low transverse cesarean. There is no increased maternal or perinatal morbidity if an attempted low transverse incision has to be converted to an inverted "T" incision compared to performing a classic cesarean section.

Am J Perinatol. 2010 Nov;27(10):791-6. Epub 2010 May 10. Maternal and neonatal outcomes of repeat cesarean delivery in women with a prior classical versus low transverse uterine incision. Bakhshi T, et al.  PMID: 20458666

We compared maternal and neonatal outcomes following repeat cesarean delivery (CD) of women with a prior classical CD with those with a prior low transverse CD. The Maternal Fetal Medicine Units Network Cesarean Delivery Registry was used to identify women with one previous CD who underwent an elective repeat CD prior to the onset of labor at ≥36 weeks. Outcomes were compared between women with a previous classical CD and those with a prior low transverse CD. Of the 7936 women who met study criteria, 122 had a prior classical CD. Women with a prior classical CD had a higher rate of classical uterine incision at repeat CD (12.73% versus 0.59%; P < 0.001), had longer total operative time and hospital stay, and had higher intensive care unit admission. Uterine dehiscence was more frequent in women with a prior classical CD (2.46% versus 0.27%, odds ratio 9.35, 95% confidence interval 1.76 to 31.93). After adjusting for confounding factors, there were no statistical differences in major maternal or neonatal morbidities between groups. Uterine dehiscence was present at repeat CD in 2.46% of women with a prior classical CD. However, major maternal morbidities were similar to those with a prior low transverse CD.