Background

Laparoscopic Roux-en-Y gastric bypass (LRYGB) has become the gold-standard bariatric procedure in dealing with obesity-related comorbidities. It has been proved effective in ensuring durable weight loss and substantial improvement in quality of life. Among the different postoperative complications of LRYGB, one of the most common is internal hernia (IH) related to the modified intestinal anatomy [1, 2]. The current standard procedure is to close all windows during LRYGB surgery. The diagnosis and management of IH remains an essential issue in bariatric surgery considering that any delay can lead to life-threatening events [1,2,3,4].

The insidious and often non-specific clinical presentation of any IH poses diagnostic and therapeutic challenges. When clinical and radiological suspicion persists, surgical exploration is still considered mandatory for both diagnostic and therapeutic purposes, coming at the cost of an occasional unnecessary exploration [1,2,3,4,5,6,7,8, 12].

Foramen of Winslow hernia (FWH) is a rare type of IH, accounting for less than 1% of all cases of hernia. Despite being rare, FWH has a historic mortality rate of almost 50% due to difficult and delayed diagnosis which often led to advanced bowel ischemia. Most cases had been managed by laparotomy, until recently, when the laparoscopic approach has been clearly favored [13,14,15,16,17,18,19,20,21,22]. Modern technologies such as last generation computed tomography (CT) and indocyanine green (ICG) angiography offer new tools for faster and better workup during IH management [23,24,25].

We report a unique case of a patient who presented with a double bowel obstruction due to a classic IH after LRYGB surgery through a Petersen’s defect and a simultaneous second obstruction site due to a FWH.

The aim of this report is to emphasize the importance of prompt surgical referral for patients with abdominal pain after LRYGB surgery and to highlight the increasing role of laparoscopy.

Case Presentation

We report the case of a 41-year-old Caucasian female patient with a current body mass index (BMI) of 27.4 kg/m2 and a history of robotic LRYGB and cholecystectomy performed at our institution 4 years earlier in the setting of our usual bariatric surgery pathway. Closure of the Petersen’s defect and jejunojejunostomy mesenteric defect was performed with running suture of Ethibond 2–0 (Ethicon J&J). The patient was referred for surgery based on morbid obesity (initial BMI of 39.8 kg/m2) with metabolic syndrome and has since lost 33.4 kg. Apart from the LRYGB, her only surgical history was of a laparoscopic appendectomy.

The patient presented in our emergency department due to severe epigastric pain with nausea and absence of flatus and stool for more than 24 h.

Clinical examination revealed pain in the middle and upper abdomen with no signs of peritonitis. Blood test revealed only a mild elevation of white blood cell count to 13.3 G/L (N ≤ 11 G/L) and no inflammatory process with C-reactive protein at 0.60 mg/L (N ≤ 10 mg/L).

An abdominopelvic computed tomography (AP-CT) showed a small bowel obstruction with moderated dilatation of the small bowel loops that tended to be localized in the left flank. An incomplete swirl sign was also visible on the CT scan. Radiological findings were suggestive of an IH after LRYGB (Figs. 1 and 2).

Fig. 1
figure 1

A coronal computed tomography view of the small bowel loops located in the left upper quadrant (black oval). The arrow indicates a partial “whirlpool sign/swirl” of the involved bowel mesenteric vessels

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Fig. 2
figure 2

The transverse computed tomography view of the small bowel loops shown in Fig. 1. The arrow indicates the incomplete swirl caused by traction on the mesentery

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Furthermore, the CT scan showed a pathologically enlarged transverse colon pushing the gastric bypass pouch to the left due to an incarcerated FWH (Figs. 3, 4, and 5).

Fig. 3
figure 3

The transverse computed tomography view showing a distended colon (black arrow) pushing the gastric bypass pouch (red arrow) to the left of the midline

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Fig. 4
figure 4

A transverse computed tomography view of the hepatic pedicle (green arrow) overlying on a dilated and obstructed transverse colon (black arrows) within the Winslow foramen

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Fig. 5
figure 5

The coronal view of the findings shown in Fig. 4. Black arrows indicate distended transverse colon

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Due to increasing discomfort and the radiological findings, the patient was quickly referred for surgical exploration. The surgery was performed laparoscopically. Initial exploration confirmed the classic IH through an enlarged Petersen’s defect containing incarcerated small bowel loops and causing a partial twist of the jejuno-jejunal anastomosis. Reduction of the small bowel was easily achieved, and direct closure of the Petersen’s defect was done with non-absorbable sutures (2–0 Ethibond).

Laparoscopic exploration also confirmed the FWH with a remarkably distended transverse colon due to its subtotal herniation under the hepatic pedicle through an enlarged foramen of Winslow (Fig. 6).

Fig. 6
figure 6

Intraoperative view of the herniated transverse colon (black arrows) under the hepatic pedicle (green arrow)

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After charging the hepatoduodenal ligament on a vessel tape for gentle traction, we achieved a complete reduction of the colonic hernia (Fig. 7).

Fig. 7
figure 7

The hepatoduodenal ligament (green arrow) is charged on a vessel tape for gentle traction. Distended colon (black arrows) is slowly reduced

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We then performed, as routinely done at our institution, indocyanine green (ICG) angiography using our in-house protocol which consists of a single intravenous injection of 7.5 mg of ICG solution (Verdye) to assess the perfusion of the affected colon. An excellent ICG signal appeared, showing a homogeneous perfusion of the whole transverse colon.

Direct closure of the enlarged foramen of Winslow was not possible due to its anatomy (Fig. 8).

Fig. 8
figure 8

Intraoperative view of an enlarged Winslow foramen, free from incarcerated colon

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We then decided to perform an atypical gastropexy by suturing the excluded stomach’s pylorus toward the hepatoduodenal ligament with non-absorbable sutures (Ethibond), thus covering the underlying Winslow’s foramen and preventing any recurrence (Fig. 9).

Fig. 9
figure 9

Final image of the non-absorbable sutures between the excluded stomach’s pylorus (red arrow) and the hepatoduodenal ligament

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The entire surgery was done laparoscopically with a 12-mm camera port and three 5-mm ports.

After surgery, the patient was allowed to start drinking and eating as tolerated.

At post-operative day 1, the patient reported no pain and showed no signs of complication. She passed stool on post-operative day 2 and was discharged on the same day.

The patient was seen at 40-day post-operative control with no residual pain and a normal abdominal examination thus requiring no further surgical follow-up. The patient was contacted more than 1 year after the surgery and reported no symptom recurrence.

Discussion

Laparoscopic Roux-en-Y gastric bypass has become the gold-standard bariatric procedure, being effective in durable weight loss, in dealing with obesity-related comorbidities and offering substantial quality-of-life improvement. Among the numerous complications of gastric bypass surgery, one of the typical mid- or long-term complications is IH related to the modified intestinal circuit. The diagnosis and management of IH remains an important issue in bariatric surgery considering that any delay can lead to life-threatening events [1, 2].

The insidious and often non-specific clinical presentation sets challenging diagnostic and therapeutic problems. Indeed, when clinical or radiological suspicion persists, surgical exploration is still mandatory for both diagnostic and therapeutic measures with a risk of occasional unnecessary exploration [1,2,3,4,5,6,7,8, 12].

IH represents the most common cause of small bowel obstruction after LRYGB with an incidence ranging from 1 to 6.2%. The incidence increases to more than 8% in case of non-closure of mesenteric windows at the time of surgery. Even with appropriate closure of those typical LRYGB defects during surgery, patients can still develop an IH years after the initial surgery. The most important and largely accepted risk factor is a major weight loss leading to reduction of the intra-abdominal adiposity and to reopening of the mesenteric defects. IH are also slightly more frequent after laparoscopic surgery due to supposed reduced adhesions [1,2,3,4,5,6,7,8].

The most typical and frequent IH sites are related to the intermesenteric defect at jejunojejunostomy and at the famous Petersen’s window defect (posterior to the gastrojejunostomy). Occasionally, a third site of herniation can occur through the transverse mesocolon in case of a transmesocolic Roux-en-Y limb reconstruction.

Diagnosis of IH after LRYGB has greatly improved in the last several years due to the increasing use of CT scan, which is performed almost systematically on any patient with history of bariatric surgery presenting with abdominal pain. CT scan remains undeniably the most recommended and preferred imaging modality. However, its sensitivity and specificity for IH diagnosis can be as low as 62% which contributes to a low negative predictive value. Therefore, in case of persistent doubt, most surgeons recommend explorative laparoscopy, which is more reliable in diagnostics and offers therapeutic possibilities [9,10,11,12].

Recently, an IH predictive score has been developed to reduce delay in IH diagnosis and encourage earlier explorative laparoscopy in case of an elevated score [12].

FWH is one of the most uncommon types of IH, accounting for about 8% of IHs and less than 1% of all hernias. Reported mortality of FWH used to be up to 49% due to their difficult and delayed diagnosis often leading to bowel strangulation. The most frequently involved organ is the small bowel (~ 2/3 of all cases) followed by the colon and rarely other organs [13, 14, 16, 18, 20]. A classification based on the involved organ has been described [13].

The foramen of Winslow, also known as epiploic or omental foramen, is a natural opening between the greater and the lesser peritoneal cavities. Its anatomical boundaries are anteriorly the hepatoduodenal ligament, superiorly the caudate hepatic lobe, and inferiorly the first portion of the duodenum. In normal circumstances, the foramen remains closed as a result of the spontaneous intra-abdominal pressure [13,14,15,16,17,18,19,20,21,22].

Most authors report multiple risk factors for FWH such as enlarged foramen of Winslow, redundant intestinal mesentery, excessive viscera mobility, and changes in intra-abdominal pressure [13, 14, 16, 19, 21, 22]. Acquired risk factors include cholecystectomy, pregnancy, or overeating among others [13, 16, 19, 20].

Clinical presentation of FWH, as in any IH, is also generally insidious and non-specific [13,14,15,16,17,18,19,20,21,22]. The symptoms vary from proximal bowel obstruction or gastric outlet obstruction with or without epigastric pain to severe abdominal pain or generalized peritonitis. Some cases of jaundice caused by direct compression of the hepatic pedicle have also been described [13, 20].

In most published cases and series, FWHs have been treated by laparotomy due to their commonly delayed diagnosis and the access needed for strangulated bowel resection. In the last decade, the improved accessibility and quality of CT scans enabled quicker and more accurate diagnosis, and laparoscopic management of FWH has emerged [13,14,15,16, 19, 21]. Surgical treatment relies on exploration, gentle reduction, and eventual Winslow’s foramen closure. The need for closure is still debated: some surgeons choose to close the foramen by direct sutures or packing of the foramen with the greater omentum while others choose not to close the foramen [13, 15,16,17,18,19,20,21,22].

ICG is a fluorescent dye that has been used for medical purposes for over 50 years. In combination with near-infrared fluorescence, ICG offers excellent assessment of in vivo perfusion of tissues and organs and is nowadays being applied in many surgical or non-surgical procedures. ICG angiography allows more organ-sparing surgeries and is therefore most beneficial to surgeons and patients [23,24,25].

In our case, the incarcerated content of the FWH was the transverse colon. As risk factors for the latter, we could identify the cholecystectomy and a redundant and mobile transverse colon, probably increased by the weight loss after LRYGB. Behavioral factors such as excessive and inappropriate eating might have also played a role.

In a 2018 literature review, Moris et al. [26] analyzed 150 reported FWH cases and found it predominantly affected man (ratio 2.5 to 1) with a peak incidence between 20 and 60 years of age. Laparoscopic approach was used in management of only 15 of the 150 cases, mostly in cases of ileum incarceration; transverse colon has been involved in only two cases [27, 28]. In 2020, Hakmi et al. [29] presented a case report of a laparoscopically managed incarcerated transverse colon IH in the Winslow foramen in a patient with Crohn’s disease.

However, this is, to our knowledge, the first case report describing a post-LRYGB patient presenting with a double bowel obstruction due to two types of IH occurring at the same time.

Surgical management was entirely laparoscopic, as the clinical situation permitted. Surgical exploration offered a clear view of the two hernias and a good access to reduce the affected bowel. A homogeneous and good-quality perfusion was obtained on the transverse colon during ICG angiography excluding the necessity for bowel resection.

Finally, all defects were closed with non-absorbable interrupted sutures to avoid any hernia recurrence. So far after 1-year follow-up, our patient presented no signs of recurrence.

Conclusions

In patients with abdominal pain and a history of LRYGB surgery, performing an AP-CT scan immediately after initial clinical examination and routine blood tests is mandatory. Because IH is a common and life-threatening complication that often requires surgical exploration, no doubt nor delay in treatment should subsist. Modern technologies such as new-generation CT scan and ICG fluorescence improve management of IH by enabling faster diagnosis and more accurate evaluation of intestinal viability, especially in case of incarcerated bowel.

We highly suggest that laparoscopic approach should always be attempted in the first instance as it seems safer and less invasive than laparotomy. If laparoscopy is technically difficult, conversion to laparotomy will often be required. Finally, we recommend closure of all IH defects in the first place or during revision of LRYGB, including FWH defects, with non-absorbable sutures to prevent hernia recurrence.