Pregnancy After WLS: The Risk for Internal Hernia

Image from Greenstein and O'Rourke,
Am J Surg, 2011

One of the risks that tends to be de-emphasized to women considering Gastric Bypass (GB) surgery is the risk of internal hernia, especially one that occurs during pregnancy.

What is an internal hernia?  Here is one definition:

An internal hernia is defined as a protrusion of intestine through a defect within the peritoneal cavity, as opposed to an external (or incisional) hernia that protrudes through all layers of the abdominal wall. Internal hernias almost always occur through iatrogenic defects created surgically.

The consequences of developing an internal hernia can include Small Bowel Obstruction (SBO), lack of adequate blood supply to the intestine and resulting necrotic tissue, gangrene, and a need for bowel resection.  In extreme cases, it can lead to death.

Granted, the risk for internal hernia is not a big risk, although it's difficult to pin down exactly what the risk really is.  One study found a 3.1% incidence of internal hernia after GB in a series of 2000 patients, while a different study found a 4.5% rate in a series of 1000 patients.  Another study found a higher rate of 6.9%.  A meta-analysis of 26 studies found an incidence of 2.5%, with a mortality rate of 1.1%.

However, these are internal hernia rates in the general GB population; the risk may be higher in pregnant women because pregnancy shifts the internal organs around and increases intra-abdominal pressure:

The incidence of internal hernia after [Laproscopic Gastric Bypass] is between 0.2 and 8.6 percent based on multiple studies...The particular case of pregnancy— with the mass effect of an enlarging uterus—may predispose to this condition...Due to the increasing scope of this problem and its potentially devastating consequences, surgeons should have a high clinical suspicion for internal hernia after LGBP.

Of course, it's important to remember that most women who have a Gastric Bypass and then a pregnancy afterwards will not experience an internal hernia.

However, there are some women who develop a hernia during pregnancy after Gastric Bypass, and it can be a very serious issue.  Women and babies have died from this complication (see case reports below). Therefore, it's important to raise awareness about this possible risk.

Any time a pregnant woman with a history of Gastric Bypass experiences significant abdominal pain, this must be taken very seriously.  

Physicians with experience both in WLS (Weight Loss Surgery), pregnancy, and intestinal issues should be consulted. Oftentimes, E.R. or family practice doctors miss internal hernias, CT scans are not always definitive, and as a result, there are a number of scary "near-miss" stories out there.  Most authorities agree that exploratory surgery is usually warranted, just in case, since a delayed or missed diagnosis is not unusual and can be deadly.

One of my concerns is whether or not this risk is adequately explained to women before they have WLS.  WLS is being actively marketed to fat women as a way to make childbearing "safer," yet are they really being told enough about this possible complication of pregnancy after GB?

And if they choose to go ahead, have the surgery, and then have a pregnancy, have they been sufficiently alerted to watch for abdominal pain and to seek help immediately if it occurs?

On a more cynical note, isn't it interesting that these cases are being recounted as case reports in the medical literature, but yet you rarely see them listed in the studies on pregnancy after WLS?  Granted, this complication is not so routine you'd see a lot of cases of it, but for every case report that is published, there are probably a number more that are not being written up.

Why isn't there more attention to this complication in the pregnancy-after-WLS literature? Given at least a 2-3% incidence of internal hernias after WLS in the general population and the number and seriousness of pregnancy-related case reports in the literature, you'd expect to see some of these documented in the large studies on pregnancy after WLS.  And yet, you almost never do.

Hmmmmmm.


References

*Note: Additional case reports can be found on Pubmed but were not listed here because they did not have an abstract available for review.

Case Reports on Internal Hernias During Pregnancy After GB

Acta Obstet Gynecol Scand. 2012 Apr 24. doi: 10.1111/j.1600-0412.2012.01421.x. Pregnant woman with fatal complication after laparoscopic Roux-en-Y gastric bypass. Renault K, et al.    PMID: 22524680

...We report a 22 year old woman, who had previously undergone uncomplicated laparoscopic Roux-en-Y gastric bypass. She was admitted with severe abdominal pain at 35 weeks of gestation. A cesarean section with delivery of a healthy baby in combination with an exploratory laparotomy was performed. Internal herniation was suspected, but not identified during surgery. Three days later she died of a severely gangrenous small bowel secondary to internal herniation. This fatal case illustrates a potential complication and difficulties in the managment of pregnant women who have undergone Roux-en-Y gastric bypass. In these women observation and investigations based on multidisciplinary approach is vital if abdominal pain develops, with involvement of intestinal surgeons experienced in bariatric surgery as well as radiologists with specific knowledge of relevant imaging procedures.

Am Surg. 2005 Mar;71(3):231-4. Small bowel ischemia after Roux-en-Y gastric bypass complicated by pregnancy: a case report. Charles A, et al.   PMID: 15869139

...This case report involves a 23-year-old female at 25 weeks gestation with a 1-day history of diffuse abdominal pain and vomiting. She had a RYGB with a 15 cc micropouch 6 months prior to the commencement of this pregnancy. All radiologic investigations were normal. Esophagogastroscopy was performed revealing an ischemic Roux limb of the gastric bypass. At laparotomy, an internal hernia involving the afferent limb was identified at the site of the Roux anastomosis compromising portions of both the afferent and Roux limbs. Nonviable portions of both the afferent and Roux limbs were resected. Gastrointestinal continuity was achieved by fashioning a gastro-gastrostomy and a jejuno-jejunostomy, thus reversing the original gastric bypass procedure. The immediate postoperative period was complicated by fetal demise. With the increase in bariatric surgery, small bowel ischemia after Roux-en-Y gastric bypass will most likely become more prevalent, particularly in women of childbearing age.

N Engl J Med. 2004 Aug 12;351(7):721-2. Maternal and fetal deaths after gastric bypass surgery for morbid obesity. Moore KA, Ouyang DW, Whang EE. PMID: 15306679  Full text available here.

[Letter to the NEJM, discussing a case report of internal hernia and complications in a woman at 31 weeks' gestation, 18 months after a gastric bypass. Both mother and fetus died.]

Surg Obes Relat Dis. 2009 May-Jun;5(3):378-80. Epub 2008 Sep 9. Internal hernia after gastric bypass surgery during middle trimester pregnancy resulting in fetal loss: risk of internal hernia never ends. Efthimiou E, Stein L, Court O, Christou N. PMID: 19026598

[No abstract available for this case report, but the title tells us the fetus died.]

Obstet Gynecol. 2005 May;105(5 Pt 2):1195-8. Pregnancy after gastric bypass surgery and internal hernia formation. Kakarla N, et al.  PMID: 15863579

BACKGROUND: Gastric bypass is a surgical procedure that is increasingly performed in the United States to treat morbid obesity. Because of the changes associated with pregnancy, women with a history of gastric bypass surgery may be at an increased risk of gastrointestinal complications during the antepartum period, as demonstrated by these cases. CASES: The first patient presented at 12 weeks of gestation with abdominal pain. Computed tomography scan revealed rotation of the small bowel mesentery. In the operating room, a Petersen's internal hernia was observed. The second patient presented at 34 weeks of gestation with epigastric pain, nausea, and vomiting. An abdominal computed tomography scan suggested distention of the biliopancreatic limb, duodenum, and bypassed stomach. She underwent exploratory laparotomy with repair of an internal (mesenteric loop) hernia. CONCLUSION: As obstetricians, we should be aware of the potential for internal hernias in pregnant patients who have undergone bariatric surgery.

Obes Surg. 2010 Dec;20(12):1740-2. Epub 2009 Mar 25. Late intestinal obstruction due to an intestinal volvulus in a pregnant patient with a previous Roux-en-Y gastric bypass. Gazzalle A, et al.  PMID: 19319613 

This is a case of a 33 weeks pregnant woman, presented 2 years after laparoscopic Roux-en-Y gastric bypass, with abdominal pain for 2 days. A laparoscopic cholecystectomy was performed 1 day earlier in another hospital, without improving the pain. She presented at our hospital with acute abdominal pain and clinical signs of intestinal obstruction, undergoing an exploratory laparotomy that revealed a volvulus and necrosis of the jejunum from the gastroenteroanastomosis through the lateral enteroenterostomy, which was resected with the reconstruction of the Roux-en-Y limb performed at the same operation. Patient and neonate presented with improvement after surgery and the patient was discharged on postoperative day 15. Internal hernias after bariatric surgery have been reported as the cause of acute abdomen problems during pregnancy, which may progress to necrosis and perforation. The delay of surgical intervention could have brought a tragic outcome for mother and neonate.

Obes Surg. 2010 Dec;20(12):1737-9. Epub 2009 Jan 28. Small-bowel volvulus in late pregnancy due to internal hernia after laparoscopic Roux-en-Y gastric bypass. Naef M, Mouton WG, Wagner HE.   PMID: 19184255

Internal hernias are a specific cause of acute abdominal pain and are a well-known complication after laparoscopic Roux-en-Y gastric bypass for morbid obesity. Although internal hernias are a rare cause of intestinal obstruction, they may evolve towards serious complications, such as extensive bowel ischemia and gangrene, with the need for bowel resection and sometimes for a challenging reconstruction of intestinal continuity. The antecolic position of the Roux limb is associated with a decrease in the incidence of small-bowel obstruction and internal hernias. The best prevention of the formation of these hernias is probably by closure of potential mesenteric defects at the initial operation with a non-absorbable running suture. We present a patient in late pregnancy with a small-bowel volvulus following laparoscopic Roux-en-Y gastric bypass for morbid obesity and discuss the available literature. For a favorable obstetric and neonatal outcome, it is crucial not to delay surgical exploration and an emergency operation usually is mandatory.

Obes Surg. 2009 Jul;19(7):944-50. Epub 2008 Oct 2. Small bowel obstruction and internal hernias during pregnancy after gastric bypass surgery. Torres-Villalobos GM, et al.   PMID: 18830790

Small bowel obstruction (SBO) is a recognized complication of Roux-en-Y gastric bypass (RYGB) surgery. Internal hernia (IH) a potential problem associated with RYGB, can have severe consequences if not diagnosed. We present two cases of SBO due to IH during pregnancy after laparoscopic RYGB (LRYGB). Both patients underwent an antecolic, antegastric LRYGB...IH should always be ruled out in pregnant patients with previous RYGB and abdominal pain. Prompt surgical intervention is mandatory for a good outcome.

Taiwan J Obstet Gynecol. 2007 Sep;46(3):267-71. Strangulation of upper jejunum in subsequent pregnancy following gastric bypass surgery. Wang CB, et al.  PMID: 17962108

...CASE REPORT: After a Roux-en-Y gastric bypass surgery, a 32-year-old woman had unrelenting epigastria for one week at 36 weeks' gestation. An emergency cesarean delivery, followed by laparotomy, was performed. A female neonate was delivered with Apgar scores of 8 and 9 at 1 and 5 minutes, respectively. Strangulation and gangrene of the upper jejunum caused by a fibrous band at the site of the Roux anastomosis were revealed. Segmental resection of the nonviable bowel was performed. The patient experienced a smooth postoperative course. CONCLUSION: The awareness of internal hernias and small bowel strangulation should be addressed when unrelenting epigastric pain is present in women after Roux-en-Y gastric bypass surgery, during their first subsequent pregnancy.

Case Reports in Obstetrics and Gynecology. Volume 2011 (2011), Article ID 415795. doi:10.1155/2011/415795.  Abdominal Pain after Gastric Bypass: Labor, Uterine Rupture, or Obstruction and Internal Hernia. Cross, SN et al. PMID: 22567508 Full text available here.

...CASE: A 26-year-old G4P1112 status post-Roux-en-Y gastric bypass required multiple urgent antenatal evaluations due to frequent episodes of abdominal pain. At 35 + 4 weeks, she presented with severe abdominal pain; initial evaluation was negative for gastrointestinal pathology. The patient was found to be in preterm labor and underwent a repeat cesarean section. The postoperative course was complicated by bowel obstruction due to internal hernia resulting in an emergent laparotomy and a prolonged hospital course....

Obes Surg. 2006 Sep;16(9):1246-8. Internal hernia with Roux loop obstruction during pregnancy after gastric bypass surgery. Ahmed AR and O'Malley W.   PMID: 16989713

We report the rare case of a pregnant woman who had undergone Roux-en-Y gastric bypass 8 months previously, and now presented with subacute small bowel obstruction secondary to internal herniation of some of the proximal Roux limb into the lesser sac through the transverse mesocolon rent, which was widely spread apart. At laparoscopy, the hernia contents were reduced and the defect was repaired. The patient made a good recovery. Because of the changes associated with pregnancy, gastric bypass patients may be at an increased risk of internal herniation. It is particularly important not to delay surgical exploration, even in the absence of a positive finding on imaging, because delay may lead to potentially devastating bowel strangulation and sepsis culminating in loss of fetus and mother.

Hum Reprod Update. 2009 Mar-Apr;15(2):189-201. Epub 2009 Jan 8. Reproductive outcome after bariatric surgery: a critical review. Guelinckx I, Devlieger R, Vansant G.  PMID: 19136457

...METHODS: English-language articles were identified in a PUBMED search from 1982 to January 2008 using the keywords for pregnancy and bariatric surgery or gastric bypass or gastric banding. RESULTS: The few reported case-control and cohort studies clearly show improved fertility and a reduced risk in obstetrical complications, including gestational diabetes, macrosomia and hypertensive disorders of pregnancy, in women after operatively induced weight loss when compared with morbidly obesity women. The incidence of intrauterine growth restriction (IUGR) appears to be increased, however. No conclusions can be drawn concerning the risk for preterm labour and miscarriage, although these risks are probably increased compared with controls matched for body mass index. Operative complications are not uncommon with bariatric surgery and several cases have pointed to the increased risk for intestinal hernias and nutritional deficiencies in subsequent pregnancy. Deficiencies in iron, vitamin A, vitamin B(12), vitamin K, folate and calcium can result in both maternal complications, such as severe anaemia, and fetal complications, such as congenital abnormalities, IUGR and failure to thrive. CONCLUSIONS: Close supervision before, during and after pregnancy following bariatric surgery and nutrient supplementation adapted to the patient's individual requirements can help to prevent nutrition-related complications and improve maternal and fetal health, in this high-risk obstetric population.

Incidence of Internal Hernias After GB

Obes Surg. 2003 Jun;13(3):350-4. Internal hernias after laparoscopic Roux-en-Y gastric bypass: incidence, treatment and prevention. Higa KD, Ho T, Boone KB.   PMID: 12841892

BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (RYGBP) has been shown to be a safe and effective alternative to traditional "open" RYGBP. Although lack of postoperative adhesions is one advantage of minimally invasive surgery, this is also responsible for a higher incidence of internal hernias. These patients often present with intermittent abdominal pain or small bowel obstruction with completely normal contrast radiographs. METHODS: Data was obtained concurrently on 2,000 consecutive patients from February 1998 to October 2001 and analyzed retrospectively...RESULTS: 66 internal hernias occurred in 63 patients, an incidence of 3.1%...20% of patients had normal preoperative small bowel series and/or CT scans..There was 1 death associated with complications of the internal hernia. The negative exploration rate was 2%. CONCLUSION: Internal hernias are more common following laparoscopic RYGBP than "open" RYGBP. Contrast radiographs alone are unreliable in ruling out this diagnosis. Early intervention is crucial; most repairs can be performed laparoscopically. This diagnosis should be entertained in all patients with unexplained abdominal pain following laparoscopic RYGBP. Meticulous closure of all potential internal hernia sites is essential to limit this potentially lethal complication.

Obes Surg. 2006 Oct;16(10):1265-71. Internal hernia after laparoscopic Roux-en-Y gastric bypass for morbid obesity. Iannelli A, Facchiano E, Gugenheim J.   PMID: 17059733

BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (LRYGBP) is associated with a relatively high incidence of internal hernias (IH) when compared to the open operation. METHODS: A search in PubMed MEDLINE from January 1994 through January 2006 was performed (keywords: obesity, laparoscopy, gastric bypass and internal hernia). RESULTS: 26 studies with a total of 11,918 patients were considered. 300 cases of IH occurred (rate 2.51%)...Mortality was 1.17%. CONCLUSIONS: IH after LRYGBP has an incidence of 2.51%. Closure of mesenteric defects with non-absorbable running suture and antecolic Roux limb are recommended. Surgical exploration for suspicion of IH after LRYGBP should be first done by laparoscopy.

Obes Surg. 2011 Dec;21(12):1822-7. Small bowel obstruction after antecolic antegastric laparoscopic Roux-en-Y gastric bypass without division of small bowel mesentery: a single-centre, 7-year review. Abasbassi M, et al.   PMID: 21656166

Reported incidence of small bowel obstruction (SBO) after laparoscopic Roux-en-Y gastric bypass varies between 1.5% and 3.5%. It has been suggested that the antecolic antegastric laparoscopic Roux-en-Y gastric bypass (AA-LRYGB) is associated with a low incidence of internal herniation (IH). Therefore we routinely did not close mesenteric defects. The records of 652 consecutive patients undergoing primary AA-LRYGB from January 2003 to December 2009 in a single institution were retrospectively reviewed...Of the 652 patients, 63 (9.6%) developed SBO. The majority (6.9%, 45 patients) had a SBO due to IH...Twenty-nine out of 63 cases had negative computed tomography (CT) findings and IH was diagnosed on CT in only 33% (14/45) of patients with IH. All patients underwent diagnostic laparoscopy. No bowel resections had to be performed. In contrast to previous reports, a high incidence of SBO with a high rate of IH at the JJ site was found in our series. Accuracy of CT is low and diagnostic laparoscopy is mandatory when SBO is suspected. Since 2010 we have started closing the JJ site, and data on SBO are collected prospectively. We believe that closing of the mesenteric defects is a mandatory step, even in an AA-LRYGB.

Am J Surg. 2004 Dec;188(6):796-800. Internal hernias after laparoscopic Roux-en-Y gastric bypass. Garza E Jr, et al.   PMID: 15619502

...METHODS: A retrospective review of 1,000 retrocolic Lap-RYGB was performed to identify those who developed postoperative internal hernias. Clinical symptoms, radiologic characteristics, and operative outcomes were analyzed to determine clinical and radiologic diagnostic accuracy (including computed tomography [CT] scan and upper gastrointestinal imaging). Subsequent independent review was performed to match operative intervention with radiologic imaging and interpretation. Operative outcomes, including the hernia closure technique, hospital length of stay, and mortality were obtained. RESULTS: Of 1,000 Lap-RYGB procedures, 45 internal hernias were identified (4.5%) in 43 patients...The most common clinical symptoms included intermittent, postprandial abdominal pain, and/or nausea vomiting (86%), although 20% had no abdominal tenderness. Initial radiologic imaging studies were diagnostic in 64%, although subsequent review of all imaging studies showed diagnostic abnormalities in 97%...The mean time to intervention for an internal hernia repair was 225 days (range 2 to 490), whereas hospital length of stay was 1.2 days (range 1 to 4). No deaths were noted. CONCLUSIONS: Internal hernias after retrocolic lap-RYGB are associated with vague abdominal complaints and limited radiologic imaging results. A high index of clinical suspicion should be used in this patient population, and surgeon review of radiology imaging studies should be performed. Prompt surgical intervention is successful and can commonly be performed laparoscopically.