Upper gastrointestinal surgery from a medicolegal perspective

Many diseases of the small intestine, large intestine, gall bladder, liver, pancreas or oesophagus may require surgical intervention. Although conditions such as peptic ulcers, bloating, heart burn, difficulty swallowing, acid regurgitation and hernias are considered benign, they can still have a significant effect on the patient’s day-to-day life. Upper gastrointestinal (GI) surgery may also be required for resection of tumours of the oesophagus and stomach. Increasingly, obese patients who have not responded to dietary management and lifestyle changes are choosing to undergo bariatric surgery, which offers a permanent solution for weight loss and reduces the risk of the many conditions, such as cardiovascular disease and diabetes, that are associated with obesity.  

Before surgery is considered, it is important that various tests are undertaken to assess suitability for surgical intervention. Endoscopy, using a small camera, can be used to visualise the upper GI tract. Oesophageal pH monitoring determines how often stomach acid is entering the oesophagus and manometry assesses the function of the pyloric sphincter, the ring of muscle at the bottom of the stomach that governs the passage of food into the small intestine. For bariatric surgery patients, the optimal procedure must be chosen, depending on the treatment goals, patient preference and risk profile, and the availability of resources and expertise.  

As with any procedure, there is a risk of complications following upper GI surgery. Many factors influence the occurrence of these, including increased age, male gender, comorbidities, very high body mass index and the experience of the treating team. Early complications include bleeding, wound infection and surgical leak. The most common complication specifically associated with bariatric surgery is peritonitis due to formation of an anastomotic fistula. Diagnosis may be difficult in obese patients, as the classic signs of peritoneal irritation may be absent, as there is no abdominal wall. If undiagnosed, sepsis can develop and lead to acute multi-organ failure, or even death. Deep vein thrombosis and pulmonary embolism are also associated with high mortality rates. Although these normally develop in the days immediately following surgery, in reality the risk persists for several months and is increased in patients with a previous history of venous thrombosis. As a preventive measure, patients should be encouraged to exercise gently as soon as possible after surgery to discourage the formation of blood clots in the legs.  

Some complications take much longer to manifest. Hernias may develop up to 2 years after bariatric surgery, often due to the patient’s substantial weight loss. These hernias may be difficult to visualise radiologically and often the only symptom is constant, non-severe abdominal pain. However, if the hernia becomes strangulated, small bowel obstruction and necrosis may result. Other causes of small bowel obstructions, which can develop at any time after surgery, are adhesions and intussusception, where part of the bowel ‘telescopes’ in on itself.  

As upper GI surgery often includes removal or bypassing parts of the small bowel, the absorption of macro- and micronutrients may be affected. Although postoperative malnutrition is rare, it can occur following malabsorbative bariatric surgery. Hence, anaemia and vitamin D deficiency are very common, occurring in up to 50% of patients. In the longer term, there is also a high risk of osteoporosis and osteomalacia. Less commonly, cases of secondary parathyroidism and neurological problems caused by vitamin B1 deficiency have also been reported. In addition, hypoglycemia is increasingly being recognised as a complication of gastric bypass surgery. It is thought that the decreased storage capacity of the stomach leads to an exaggerated release of insulin, which is exacerbated by the patient’s weight loss following surgery. In order to avoid these complications, the nutritional status of patients who undergo this type of surgery should be monitored closely. Measurements of electrolytes, minerals and vitamins should be carried out every 3 months in the first year after surgery, and every 3–12 months thereafter, depending on symptoms. Many patients will require vitamin supplementation for the rest of their lives.  

Upper GI surgery has also been associated with an increased incidence of nosocomial infection with bacteria and Candida yeast species. This is thought to be because surgical intervention alters the physiologic flora of the gut and also directly damages the body’s natural barriers to infection. Additional risk factors include the presence of comorbid conditions such as immunosuppression and cancer, malnutrition, tube feeding and the use of invasive catheter lines. Candida infection increases the mortality rate associated with surgery compared to patients with purely bacterial infections. Additionally, there is often a requirement for repeated surgical procedures, which increases the risk of further complications.  

Upper GI surgery is generally very safe, with a 30-day mortality rate of around 1% postoperatively. As many procedures are now performed using keyhole techniques, the rates of mortality and morbidity associated with this type of surgery have decreased and patient satisfaction is high. However, it is important that patients are aware that there is still a possibility of complications, some of which could develop many months later. In particular, changes in the absorptive ability of the small bowel may lead to nutritional imbalances and the requirement for dietary supplements for life.