Know when it's time for weight loss surgery CONTINUED

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What are the pros & cons of the different approaches?
Vertical banded gastroplasty (VBG) VBG is a purely restrictive procedure (see Figure 1) with no malabsorption component and no dumping. Dumping syndrome refers to rapid gastric emptying of undigested stomach contents into the small intestine, in people who've had surgical gastric bypass. The main symptoms are abdominal cramps, nausea and vomiting. Anemia is rare in VBG and vitamin B12 deficiency is almost unknown. Patients have to be very careful to chew their food completely to avoid vomiting. Although sodas and ice cream go down pretty well, they should still be avoided because of the high calorie content.

Complications of VBG include leakage, stenosis with persistent vomiting, ulcera­tion, wound infection and incisional hernia (in the open cases), as well as band erosion with life-threatening gastrointestinal bleeding. Perioperative mortality is approximately 0.1-0.5% and excess weight loss after 5 years averages ~50%. The procedure isn't used in North America and is being supplanted in Europe and elsewhere by laparoscopic adjustable gastric banding (LAGB).

Laparoscopic adjustable gastric banding (LAGB)
Adjustable gastric banding was popularized by Dr. Lubomyr Kuzmak, who devised a band with an inflatable balloon as the lining (Figure 2). This balloon is connected to a small reservoir placed under the skin of the abdomen; with this, the balloon may be inflated (thus reducing the size of the stoma) or deflated (enlarging the stoma). Adjustable bands can now be inserted laparoscopically, saving the patient the discomfort and complications of a large incision. There's no anemia, dumping or malabsorption, but the disadvantages include the need for strict adherence to diet­ary guidelines. Since patients don't always follow these guidelines, the rate of unacceptable weight loss (i.e. insufficient weight loss, from the patient's perspective) is > 30%.

Complications include band slippage, band erosion and port infection or deflation/leakage. Overall, this is a safe operation, however, with mortality rates of ~0.01- 0.05%. The expected weight loss with this procedure is 0.5-1 kg per week, amounting to excess weight loss at 5 years of ~ 50%.

Laparoscopic sleeve gastrectomy (LSG)
In this approach, up to 80% of the stomach is resected. LSG has been used as a first-stage baria­tric procedure to reduce surgical risk in very heavy patients (> 200 kg). Indeed, this may be the procedure's most useful application at the present time. The mechanism of weight loss and resultant comorbidity improvement may be related to a reduction of the eating capacity, or it may have to do with neuro­humoral changes following the removal of most of the stomach. Alternatively, it may be the result of some other, unidentified factor(s). If weight loss stops before the targeted goal is achieved, LSG can be converted to biliopancreatic diversion with duodenal switch or to gastric bypass. LSG alone doesn't create malabsorption.

Biliopancreatic diversion (BPD)
This procedure involves a limited gastrectomy and attachment of the lower 200-cm segment of the small intestine to the remaining stomach pouch, creating an alimentary limb (Figure 3). The long remaining biliopancreatic limb is connected to the lower part of the alimentary limb, leaving a common channel 50-75 cm in length. The approach creates significant malabsorption, which acts to maintain weight loss in the long run.

From the patient's perspective, the great advantage of this operation is the ability to eat large quantities of food while achieving long-term weight loss. Disadvantages are the association with loose stools, stomal ulcers and foul-smelling stools and flatus. The most serious complication is protein malnutrition - which can cause hypoalbuminemia, anemia, edema, asthenia and alopecia - and generally requires hospitalization and 2-3 weeks of hyperalimentation. BPD patients need to take supplemental calcium and vitamins, particularly vitamin D, for the rest of their lives. Because of the potential for significant complications, they require lifelong follow-up.

Biliopancreatic diversion with duodenal switch (BPD/DS)
This approach combines a 70-80% gas­trectomy, reducing the stomach along the greater curvature (sleeve gastrectomy), with a duodenal switch - the lower part of the small intestine is connected to the beginning of the duodenum rather than directly to the stomach (Figure 4). Continuity of the gastric lesser curve is thus maintained while the stomach volume is reduced. The efferent limb acts to decrease overall caloric absorption and creates a long biliopancreatic limb diverting bile from the alimentary contents, specifically to induce fat malabsorption. As with BPD, the biliopancreatic limb is reattached to the lower part of the alimentary limb. The BPD/DS procedure minimizes stomal ulcer and dumping syndrome.

BPD and its variants are complex procedures, and prospective patients who wish to consider BPD/DS should seek out experienced surgeons with lifelong follow-up programs. Mortality is ~1% in the best centres, and excess weight loss of > 67% after 10 years has been reported.