Surgical risks

Obesity surgery may be associated with complications that are common to any abdominal gastrointestinal surgery including:

  • General anaesthesia: patients who are obese are at greater risk of surgical anaesthetic complications.
  • Pulmonary embolism: this condition occurs when a blood clot in the leg (deep venous thrombosis) breaks off and travels to the lungs. Sometimes this can cause sudden death but most patients develop sudden shortness of breath. This occurs in about 1% of patients. To help prevent this, you may be put on blood thinning medication (heparin) and given compression stockings while in hospital. You will also be encouraged to get out of bed and walk as soon as possible after surgery.
  • Infection: the risk of infection is generally low. Lung infections are rare if you follow the post-operative respiratory physiotherapy guidelines. Abdominal and urinary infections are rare and can be treated with antibiotics.
  • Leaks: leaks from the gastrointestinal tract can occur where the bowel and stomach are connected and sewed. If a complete seal does not form, bowel contents can leak into the abdomen causing a serious infection. This occurs in about 0.5-3% of cases of gastric bypass, sleeve gastrectomy and biliopancreatric diversion. It is extremely rare in gastric banding. If a leak is suspected, you may need X-ray testing or emergency surgery.
  • Heart attack: obese patients are at increased risk of developing a heart attack due to the higher cardiovascular risk (such as high blood pressure, Type 2 diabetes, high cholesterol).
  • Bleeding: can occur in 3–5% of cases and is usually resolved by stopping the blood thinning medication (heparin) which prevents blood clotting and pulmonary embolism. Occasionally surgery may be needed to stop the bleeding.
  • Bowel obstruction: bowel obstructions can be caused by scar tissue in the abdomen, kinking of the bowel, or the development of an internal hernia. It can occur in up to 5% of cases and a further operation may be needed to correct it.
  • Spleen injuries: these are rare but have occurred during surgery. In some cases you may have to have your spleen removed.
  • Incisional hernia: this occurs more frequently in the open surgery technique and is rare when using the laparoscopic ‘keyhole’ technique. It usually requires an operation to repair the hernia.
  • Anastomotic stricture: can occur in up to 5% of gastric bypass and biliopancreatic diversions. This usually responds to balloon dilatations (endoscopic procedure).
  • Death: there is about 1% risk of death associated with the surgery although this can change in relation to the surgical procedure (lower for gastric banding) and your clinical conditions. This is usually due to a pulmonary embolism or a gastrointestinal leak.