Bariatric Surgery: Indications, Patient Selection, Current Surgical Options, Possible Complications

Bariatric surgery has been devised for the treatment of people suffering from morbid obesity. It is necessary to know about the indications of bariatric surgery. People who have been advised bariatric surgery need to understand about the patient selection, preparations and the current surgical options for bariatric surgery.

The first recorded proper bariatric operation, the jejunoileal bypass (JIB), dates back to 1954. The JIB was the most popular procedure in the 1960s. Vertical banded gastroplasty was devised and then came the gastric bypass which then became the gold standard in the United States.

The laparoscopic era proclaimed a paradigm shift in bariatric surgery such that all procedures are now able to be carried out laparoscopically. Most bariatric procedures are aimed at the stomach in an attempt to restrict the amount the patient can eat. Some of these procedures also add an element of gastric and small intestinal bypass to produce a degree of malabsorption.

Obesity is a multifactorial metabolic disorder which essentially manifests itself as a surplus of other complications that indicate the need for weight loss. Such conditions are called morbid obesity, which often form the indications for bariatric surgery.

Complications of morbid obesity and common indications for bariatric surgery include:

• Type II diabetes mellitus
• High blood pressure
• Dyslipidemia
• Obstructive sleep apnea
• Venous and lymphatic stasis
• Osteoarthritis
• Decreased mobility
• Chronic respiratory hypoventilation (Pickwickian syndrome)
• Hypertrophic cardiomyopathy
• Pseudo tumor cerebral (idiopathic intracranial hypertension)
• Poor quality of life
• Urinary stress incontinence
• Gastro-esophageal reflux disease

Bariatric surgery is often considered in order to prevent the diseases arising out of morbid obesity and other complications related to it. However, patient selection for bariatric surgery is important so as to provide the best treatment and offer the most effective surgical option. Let us understand about patient selection and preparation for bariatric surgery.

• All surgical candidates should be seen by the bariatric multi-disciplinary team.
• All patients need some dietetic assessment which may help to choose the correct operation for them.
• In addition, they must be seen by a physician who specializes in treating obesity to screen for endocrine disorders and to establish the degree of metabolic syndrome present.
• All patients should also have a psychological screen to determine whether there are any unresolved issues to be dealt with either pre- or postoperatively.
• The patient should fulfill the following criteria to be approved for the operation. This is an important part of patient selection for bariatric surgery.
• Patient must have some serious comorbid disease treatable by weight loss.
• The Body mass index (BMI) should be greater than 40 kg/m2 or BMI 35–39 kg/m2.
• The patient must have a minimum of 5 years obesity.
• Failure of conservative treatment in the patient.
• No alcoholism or major untreated psychiatric illness must be recorded.
• The patient must avoid if likely to get pregnant within 2 years.
• The patient must belong to the age group of 18–55 (relative)
• The patient must should be acceptable for operative risk on preoperative assessment
• Another necessary aspect of patient selection for bariatric surgery is preoperative nutrition screen.
• The patient must have a full blood count.
• The electrolytes must be in a balanced state.
• Liver function tests must be performed to ensure the proper functioning of the liver.
• Fasting lipid profile must be recorded to regulate the blood sugar levels.
• Fasting glucose, HbA1C are mandatory in patients with diabetes.
• Vitamins A, D, and E must be in a balanced concentration.
• The concentration parathyroid hormone must be optimum in the patient.

The surgical options have varying degrees of gastric restriction from pure (banding) to least (standard biliopancreatic diversion). All procedures are usually carried out laparoscopically and increasingly through fewer access ports as instrumentation and techniques improve.

Some of the current surgical options for bariatric surgery include

Around half of all surgical procedures in many countries are gastric bands which involve putting an adjustable band around the upper stomach leaving a small pouch just below the cardia. The degree of restriction can be controlled by the amount of fluid injected into the subcutaneous port.

Gastric banding is certainly the least risky procedure (0.1 percent perioperative mortality) as it does not involve cutting any stomach or bowel and is a relatively easy operation to perform in most patients who have a BMI <50 kg/m2. Most patients can expect to lose around 45–50 percent of their excess weight. Gastric banding is one of the most popular current surgical options for bariatric surgery.

However, some disadvantages of gastric banding have been noted, which include.

• Some patients obtaining poor weight loss eventually requiring a provisional procedure.
• Bands can fail due to prolapse of the stomach through the band
• The band can slip up or down from its initial position.
• Need for continual band adjustments in the early postoperative period and occasional long-term adjustments.

This is relatively newer of the current surgical options for bariatric surgery and requires less postoperative monitoring. In this, the stomach is reduced to 15% of its original size by surgical removal along the greater curvature. A longitudinal resection of stomach starting from antrum and finishing at fundus close to cardio is done. This results in a sleeve or tube-like stomach.

Advantages of sleeve gastrectomy: –

• Around 65 percent excess weight loss can be expected at two years.
• Relative technical ease.
• The lack of potential malabsorption problems
• There is an option of doing a relatively safe second-stage procedure if needed.

The gastric bypass is a very effective weight loss procedure but is performed with a myriad of technical variations making comparisons difficult. However, overall it produces 65–75 percent excess weight loss. Variations in the actual gastric bypass technique include ante colic versus retro colic Roux limb placement, varying alimentary and biliary limb lengths, additional banding of the gastrojejunal anastomosis to prevent dilatation, etc.

Gastric bypass is a very effective operation for alleviating and even curing type II diabetes – the result being almost immediate and independent of weight. Follow up is important to avoid any deficiency syndromes. It is one of the most widely performed current surgical options for bariatric surgery.

This surgical option for bariatric surgery can cause malabsorption but is the most effective with 75–85 percent excess weight loss. BPD can be very effective, especially in those patients with a very high BMI. A BPD also has the same rapid effect as a gastric bypass for alleviating diabetes independent of weight loss.

The duodenal switch variation of the BPD was designed to reduce the need for taking vitamin B12 and reduce the incidence of anastomotic strictures at the gastrojejunal anastomosis. In the standard BPD, approximately two-thirds of the distal stomach is removed while in the duodenal switch variation there is a vertical sleeve gastrectomy.

In the duodenal switch variation, the anastomosis is made to the first part of the duodenum rather than the stomach as in the standard BPD.

In reality, there is very little difference between these two procedures in terms of weight loss and long-term complications despite some assertions to the contrary.

Though bariatric surgery is a simple procedure with minimal risks involved, some possible complications in a bariatric surgery include

• Bleeding
• Infection
• Deep vein thrombosis (with or without pulmonary embolism)
• Accidental bowel perforation
• Perioperative mortality
• Risks of specific bariatric procedures: –
• Internal herniation (gastric bypass and BPD)
• Staple line/anastomotic leak (gastric bypass, sleeve gastrectomy, BPD)
• Band slippage/erosion
• Pouch dilatation (gastric band, gastric bypass, sleeve gastrectomy)
• Long-term risks of all bariatric surgery
• Protein-calorie malnutrition
• Vitamin and micronutrient depletion syndromes
• Weight regain

Overall, bariatric surgery is the only effective long-term treatment for morbid obesity. By knowing the indications, patient selection and preparation for bariatric surgery can help in taking an informed decision. Also, the current surgical options for bariatric surgery are promising enough and the decision is taken with the team of experts, considering the possible complications.

Evidence for initial and medium-term success of bariatric surgery is overwhelming. Extension of the principles of surgery for obesity to other metabolic conditions, especially type II diabetes mellitus, will increase its usage. Newer techniques for performing this type of surgery promise to offer fewer complications, less invasive surgery and better outcomes.