Bariatric Surgery

The National Institutes of Health in 1991 verified the documented effectiveness of Vertical Banded Gastroplasty (VBG) and Roux-en-Y Gastric Bypass (RYGB) in appropriate patients in achieving significant, maintained weight reduction. Over time the criteria for "successful" outcomes from bariatric surgery have been revised. With regard to weight loss, just one of the measures of outcome, it is now generally agreed that "success" is defined as having shed at least 50% of one's pre-operative "excess" weight, and maintaining at least a 50% "excess" weight loss over time. In the 1980's, VBG became the most commonly performed procedure by members of the ASBS.

The original VBG pouch sizes were calibrated typically at 20-30 ml. (up to one ounce), but experience documented that those pouches dilated significantly, and in patients who later failed to maintain initial weight loss, and who came to operative revision, many had pouches which had expanded to 120-180 ml., or more. Some came to revision because of narrowing of the band-reinforced pouch outlet, resulting in vomiting and reflux, others because of staple line disruption, and the consequent ability to eat more. However, the majority of the 30-40% of VBG patients who failed to reach 50% excess weight loss, or once there, maintain that degree of weight loss, were patients who were sweets -snackers to begin with, or those who continued to eat as much as possible at mealtime, snack, and exercise little.

The frequency with which VBG is performed by members of the ASBS has dropped significantly in the 1990's. Experienced bariatric surgeons recognize that patients` weight loss outcomes are related only in part to the procedure they've undergone. Moreso they relate to what they can, and do, with regard to exercise, whether they learn to eat more appropriately and downsize their meals, avoid snacking, and drink more between meals, avoiding as much as possible artificially-sweetened drinks. VBG, unfortunately, only influences meal size.

RYGB combines not only stomach stapling to create a small gastric pouch (depending upon the procedure, of varying size and configuration), but also by excluding a large part of the stomach and duodenum from the "food stream," the length of small bowel in which food and enzymes are present together is shortened, and the calories in the food consumed are then only partially absorbed. Patients undergoing RYGB average greater percentage excess weight loss than those that have had VBG, but they also must be followed yearly, taking daily vitamin-mineral supplements, and have blood studies regularly (generally yearly).

There are significant variations in the RYGB(s), as they are performed by bariatric surgeons. Those differences in technique appear to have relationship to weight lose outcomes, and early, and longer term complications. Published experience by many members of the ASBS document that original pouch size and configuration relates significantly to the size to which the pouch will dilate over time. An enlarging pouch generally means that a patient can eat more, and "store" more food. The further a pouch extends down on the lesser curve of the stomach, the greater is the acid content in the pouch, and this appears related to the incidence of ulcer formation in the pouch, which has been reported to be as high as 15%. Ulcers require medical management that may be lengthy, and sometimes operative intervention, to achieve healing. In addition, the way in which the opening between the pouch and the "bypass" segment is stapled has significant relationship to the incidence of scarring and narrowing of that opening, which has been reported in some series to be as high as 25%.

These factors have influenced Dr. Sweet's decision to create a "micropouch," with stapling of the stomach at the junction of the esophagus and stomach, with the pouch not extending down more than 1 cm. (two fifths of an inch) on the lesser curve side of the stomach. In addition, the stapled opening from the pouch to the bypass segment is circular, not linear. With this technique his incidence of marginal ulcer is less than 0.5%, and he's had no patient in his series of over 400 patients with pouch outlet narrowing (stenosis) requiring endoscopic dilation.