Bariatric surgery: Complications

Bariatric surgery or weight loss surgery includes multiple procedures for morbidly obese patients. Bariatric surgery is typically reserved for patients with a BMI > 40 or BMI >35 with obesity related complications. Bariatric surgery procedures are conventionally classified as malabsoptive, restrictive, and combined procedures. Several complications are found in all bariatric surgery procedures as outlined below. While, other complications are surgery specific.

Complications can be broken into two categories, early (< 30 days after surgery) and late (> 30 days after surgery).

Early complications related to all bariatric surgical procedures include complications typically associated with other abdominal surgical procedures:

• Bleeding
• Infection
• Dehydration
• Bowel obstruction
• Perforation
• Pneumonia
• DVT or PE
• Death

Late complications related to all bariatric surgical procedures include the following:

• Cholelithiasis
• Cholecystitis
• Pouch dilation
• GERD or dysphagia
• Herniation at surgical site
• Nutritional deficiencies, especially fat soluble vitamins and B12

The restrictive procedures include vertical banded gastroplasty and adjustable gastric banding. As one would expect, common complications for these procedures are related to obstruction or loss of restriction, and reflux.

• Stomal obstruction can occur acutely 2/2 excess perigastric fat or excessive edema. Symptoms include nausea, vomiting and inability to tolerate PO or secretions. Band adjustment is treatment vs. conservative management.
• Band erosion has been reported in up to 7 % of patients and is a late complication. Symptoms include infection, nausea/vomiting, epigastric pain and hematemasis. Surgical intervention is required.
• Band slippage resulting in gastric prolapse can occur, when slippage is anterior (band moves cephalad) obstruction results, when slippage is posterior (band moves caudad) another pouch results, symptoms include reflux, epigastric pain, and food intolerance.
• Esophagitis and reflux can occur and are typically managed with deflation of band and acid suppression.
• Esophageal dilation in the setting of excessive intake relative to band inflation, behavioural modification and band deflation are mainstay of treatment.

Specific complications from a sleeve gastrectomy:

• Bleeding from the gastric vasculature typically intraoperatively,
• Stenosis can occur with symptoms c/w gastric outlet obstruction and managed by endoscopic dilation or if necessary surgical intervention,
• Gastric leaks can occur 2/2 tissue ischemia or hypoxia and may require re-operation
• Reflux can occur both early or late and is managed medically.

Specific complications from vertical banded gastroplasty (stomach stapling)-

• Staple line disruption can occur leading to decreased restriction and weight regain
• Obstruction as previously discussed
• Erosion of mesh band is typically a late complication and requires surgical intervention
• Reflux managed with medical therapy

Malabsorptive procedures are less commonly performed today. These procedures include jejunoilial bypass (historically performed in the 1960s and 1970s) and biliopancreatic diversion (performed in few centers in the US).

• Biliopancreatic diversion- common complications include protein malnutrition, anemia, diarrhea, and stomal ulceration.
• Jejunoilial bypass- surgery essentially creates a short bowel and thus short bowel symptoms. Renal failure was more common secondary to increased absorption of calcium oxylate. Hepatic abnormalities were common and many developed cirrhosis.

Combined procedures (both restrictive and malabsorptive) classically the Roux-en-Y gastric bypass. Complications include:

• Anastomotic leak is a fairly specific complication requiring surgical intervention.
• Dumping syndrome is a common early complication; however, it is typically self limited and can be managed by diet modification.
• As many as 38% of patients can develop cholelithiasis in the six months following surgery. The etiology is believed to be rapid weight loss leading to increased lithogenicity of bile.
• Gastric remnant distention is a potential complication that if it ruptures can be devastating secondary to large inocullum into the abdomen, emergent operative decompression would be indicated.
• Stomal stenosis can develop that leads to nausea/vomiting, GER and can lead to inability to tolerate PO intake. Balloon dilation is mainstay of treatment.
• Marginal ulcers near the gastrojejunostomy site can occur secondary to high acid concentrations ultimately damaging the jejunum. Treat the underlying cause (H.pylori or discontinue NSAIDS) and acid suppression and/or sucralfate.
• Renal failure secondary to increased absorption of calcium oxalate has been reported although it is uncommon.
• Loose stool and diarrhea is frequent in gastric bypass patients.