Gastric remnant perforation after single anastomosis gastric bypass

Gastric remnant perforation is rare in the short-term after surgery. However, it highlights the vulnerability of the gastrointestinal system in the early healing phase. There is a degradation of esophageal and colonic anastomotic strength by 40% and 70% respectively after 48 hours due to the inflammatory phase of intestinal healing which increases collagenase proteolytic activity [1],[2]. These factors would make the staple line anastomosis of a bypassed stomach vulnerable to perforation in the context of increased intra-luminal pressure from a concurrent small bowel obstruction. A study of sleeve gastrectomy specimens found that half of the leaks occurred at the staple line with most occurring at the junction between staple lines [1].

A 42-year-old male presented to an Emergency Department six days after elective laparoscopic removal of adjustable gastric band, hiatus hernia repair, and single anastomosis gastric bypass for weight loss [weight 155 kg, height 187 cm, body mass index (BMI) 44 kg/m²] with sudden onset generalized abdominal pain and fever. His past medical history was only significant for obesity and he took no regular medication. He did not use tobacco, alcohol, or illicit substances. There was no family history of peptic ulcer disease. He had generalized abdominal tenderness on examination and tachycardia to 130 bpm.

His leukocyte count was 14.6 × 10⁹/L (Normal range: 4.0–10.0 × 10⁹/L), C reactive protein 518 mg/L (<3 mg/L), creatinine 273 umol/L (60–110 umol/L), and lactate of 3.4 mmol/L (<1.9 mmol/L). Computed tomography (CT) with oral contrast showed an intra-abdominal abscess, pneumoperitoneum (Figure 1), obstructed small bowel without a transition point (Figure 2) and extra-luminal oral contrast (Figure 3).

Differential diagnosis

The differential diagnosis for his acute presentation would be:

• Anastomotic leak with intra-abdominal sepsis
• Viscus perforation
• Complicated internal hernia
• Perforated gastroduodenal ulcer

Post-operative patients presenting with abdominal pain, early shock, and significantly elevated inflammatory markers raise warrant early investigation intra-abdominal sepsis with CT imaging. The radiological findings combined with the clinical presentation suggested there was a viscus perforation or anastomotic leak combined with small bowel obstruction. A perforated viscus may be the result of a strangulated section of bowel from an internal hernia or pressurization of the bowel. A gastro-duodenal ulcer perforation would be an unlikely cause as these patients routinely have a gastroscopy prior to or at the time of surgery.

Operative findings

At operation there were acute abdominal adhesions and dilated small bowel proximal to the gastroenterostomy with collapse of the bowel distal to the anastomosis. There was a large volume of bile-stained gastric fluid in the supracolic compartment with an intra-abdominal abscess overlying the left lobe of the liver. There was pressurization of the gastric remnant from the obstructed afferent small bowel loop and perforation at the pyloric end of the staple line of the gastric remnant (Figure 4).

The perforation was repaired primarily, followed by oversew of the staple line and reinforcement with an omental patch before extensive abdominal washout and placement of two 10 mm Jackson–Pratt drains. Over the next 14 days he was treated with bowel rest, total parenteral nutrition, endoscopic dilation of the gastroenterostomy anastomosis to 19 mm and percutaneous drainage of left subphrenic and pelvic collections as well as a left pleural effusion.

Follow-up

His community recovery was complicated by a right lower limb deep vein thrombosis and recurrent left pleural effusions requiring pigtail catheter chest drainage. He was admitted three months after discharge with bilateral pleural effusions requiring intravenous antibiotics and pigtail catheter drainage. Following this admission, he recovered to his baseline level of function including return to employment and continued independence with all activities of daily living. After resolution of his deep vein thrombosis, his anticoagulation was ceased.

Early small bowel obstruction occurs in 0.5–5.2% of patients after Laparoscopic Roux-en-Y gastric bypass (RYGB), the incidence after SAGB is unknown [2]. Overall anastomotic leak rates after SAGB are estimated at 1.7% and acute gastric remnant leaks are rare 0.03–0.2% [2],[3],[4] while late perforations occur at a median of 18 months in 1% of patients [5]. Early obstruction is particularly concerning in this situation where there is a healing staple line which is at risk of leaking.

The principles of immediate management are lavage of the intra-abdominal contamination to control the infection, repair the source of the leak, and alleviate distal obstruction. Early laparoscopy enables thorough washout of infection substrate and repair of any perforation. Abdominal drain placement facilitates clearance of residual contamination. The literature reports varying management options: surgical (laparoscopic washout, drainage, T-tube placement or conversion to RYGB), percutaneous drainage and/or endoscopic (T-tube placement or pigtail drain insertion) [6]. Treatment should be guided by whether a discrete point of leak may be repairable, the volume and morphology of intra-abdominal contamination, as well as clinical condition.

This patient did not have any signs of symptoms to indicate there were any surgical complications prior to discharge following his original surgery and this highlights the importance of early review and imaging for patients who do not follow a standard clinical course in the post-operative period.

We recommend early laparoscopic washout, perforation primary repair, and omentoplasty followed by suture reinforcement of the entire staple line. Surgeons should consider suture reinforcement of staple line anastomosis as primary prevention for anastomotic leak as this provides the highest perforation resistance.