Gastric sleeve surgery is currently the most commonly performed weight loss procedure in Houston. With this increase in gastric sleeve popularity, we have witnessed a rising number of patients with insufficient weight loss following gastric sleeve surgery. Weight loss following any bariatric procedure like sleeve gastrectomy and gastric bypass surgery varies among patients. Percent excess body weight loss follows a bell shape curve. Patients who are poor responders to gastric sleeve surgery are candidates for either Roux-en-Y gastric bypass surgery, or duodenal switch procedure. Gastric sleeve conversion to either gastric bypass or duodenal switch is a straightforward surgery since no bridges are burnt. The question, however, is which revision procedure is best recommended?

Gastric bypass surgery and sleeve gastrectomy are almost equally effective in terms of weight loss and comorbidity resolution. Both procedures accelerate gastro-intestinal motility and increase post-prandial neuro-endocrine secretion of GLP-1 and PYY. Studies in rodent models have demonstrated increased metabolic rate after gastric bypass but not gastric sleeve surgery. In humans, however, gastric bypass surgery does not seem to increase the metabolic rate. Accordingly, gastric sleeve conversion to gastric bypass, in poor responders, is less likely to improve weight loss. At Houston Weight Loss Surgery Center, we favor gastric sleeve conversion to duodenal switch in theses cases. Duodenal switch surgery is the most effective weight loss procedure associated with the highest rate of diabetes resolution and percent excess body weight loss. Duodenal switch mechanism of action differs from that of gastric bypass and sleeve surgery. Duodenal switch is more likely to benefit non-responders to gastric sleeve surgery than gastric bypass. Duodenal switch procedure is technically more demanding than gastric bypass or sleeve surgery. Duodenal switch causes nutrient and vitamin malabsorption. Non-compliant patients may not be the best candidates for duodenal switch surgery.

Of note, a poorly performed gastric sleeve resulting in poor weight loss is best converted to gastric bypass. Typically, a poorly performed gastric sleeve is associated with a narrowed incisura angularis, dilated or retained gastric fundus and acid reflux. In such situations, we strongly advocate the conversion of sleeve to gastric bypass to stop acid reflux and improve weight loss.