Gastric Bypass Complications
Certain complications are seen during the early postoperative periods while others may present weeks to months following the surgery.
- Mortality (death) has been reported at approximately 0.13% for laparoscopic gastric bypass. Leaks were responsible for approximately 50% of the deaths and pulmonary embolus was the cause at approximately 30%.
- Bleeding both during and immediately after surgery. Bleeding after gastric bypass has been reported in 0.6 to 4.0% of patients. If bleeding occurs, a transfusion of blood products may be necessary. Surgery is reserved for continued bleeding or severe bleeding.
- Infections can occur after surgery including lung infections, incision site infections or internal staple lines (anastomosis lines). These infections may only require antibiotics, but surgery may be required depending upon the type and degree of infection. Wound infections have been reported to occur between 3 to 4%. Pre-operative antibiotics are used to reduce wound infections. Signs of wound infections include unexplained fevers, redness (erythema), or drainage.
- Blood clots can form in blood vessels during or after surgery. A blood clot can develop in the leg called a deep vein thrombosis (DVT). A blood clot that travels is called an embolus. Pulmonary embolism (PE) remains one of the leading causes of early mortality following gastric bypass. The use of heparin, pneumatic compression boots, and early post-operative walking are techniques used to prevent PE and DVT.
- Leaks may occur anywhere the stomach or small intestine is re-connected (anastomosis). If a leak happens, it must be treated right away. Re-operation may be needed to fix the leak. Leaks from gastrointestinal tract are another major cause of post-operative mortality. The chance of a leak occurring after gastric bypass surgery has been reported to be between 0 and 5.1%. Early symptoms of a leak are low-grade fevers, difficulty breathing, or an unexplained increase in heart rate. The concern is that a severe infection called sepsis is occurring. An exploratory surgery may be necessary without delay.
- Malnutrition, dehydration, or anemia. Malnutrition occurs when your body is not receiving enough nutrients, like iron, protein, vitamins, and minerals. Following the recommendations regarding food choices and vitamin supplements is extremely important. Dehydration occurs when you are not drinking enough water. Anemia causes you to feel very tired, and weak, and you may become pale because fewer red blood cells are available to carry oxygen. You need to take iron supplements as recommended. Further information is provided in this education booklet about prevention of malnutrition.
- Marginal Ulcer may occur at the edges of your stomach pouch where the staple line exists. A marginal ulcer destroys the inner lining of the small intestine that is adjacent to the stomach pouch. This can cause bleeding, pain, and can even result in perforation. Irritants that have been shown to lead to a marginal ulcer are the following: tobacco, steroids (such as Prednisone), anti-inflammatory drugs (such as aspirin and ibuprofen), caffeine or alcohol. Marginal ulcers have been reported to occur in up to 13% of gastric bypass patients. Eliminating the irritant and taking prescribed medications can usually heal the marginal ulcer, but sometimes surgery is necessary. Smoking is a major cause of marginal ulcers and you must not re-start smoking after surgery at anytime. Ulcers may occur years after the bypass surgery.
- Blockage of the small intestine prevents food or liquids from passing through the intestines. The blockage can be caused by scar tissue (adhesions) that narrows or totally blocks the intestines. You may feel nauseous, have abdominal pain, or vomit. In some cases another operation may be needed.
- Hernias occur because a portion of the intestine is pushing outward due to a weakness of the abdominal wall. Ventral incisional hernia and internal hernia are the two different types of hernias. An internal hernia can occur after gastric bypass surgery because of the re-routing of the small intestine. The location of the internal hernia is associated with the internal spaces through which herniation of the small intestine can occur. The incidence of an internal hernia has been reported to be 1 to 5%. Severe pain and vomiting resulting from a strangulating internal hernia will require immediate surgery. Hernias may present years after the surgery.
- Gallstones may form in the gallbladder causing the tube coming out of the gallbladder to be blocked by the stones. Rapid weight loss increases the development of gallstones. Removal of a person’s gallbladder is not routinely recommended at the time of gastric bypass surgery.
- Stomal stenosis or stricture is a narrowing at the bottom of the stomach pouch that prevents food from leaving the stomach pouch easily. Stomal stenosis typically occurs several weeks after surgery with symptoms of nausea, vomiting, dysphagia (difficulty swallowing), reflux, and inability to tolerate food or fluids. Stomal stenosis has been reported in 6 to 20% of patients who have laparoscopic gastric bypass surgery. An endoscopy or an upper gastrointestinal series is used to determine if a stomal stenosis has developed. An endoscopic balloon is used to stretch (dilate) the narrowing at the bottom of the stomach pouch. Repeat dilatations may be required for some patients.
Long-Term Considerations with the Gastric Bypass