Measurement of Functional Pouch Volume following the Gastric Bypass Procedure.

BACKGROUND: The cottage cheese test was developed in an attempt to find a simple way to measure functional pouch volume and to better understand the fate of the tiny proximal pouch following the gastric bypass procedure. METHODS: Our patients were asked to eat cottage cheese in a structured fashion before their return visits from 3 months to 2 years postoperatively. RESULTS: We found there was a step-wise progression of increase in functional pouch volume with statistical significance between each time interval. Also, we compared the patients' excess weight loss at 1, 2, and 3 years postoperatively to their pouch size at 1 year postoperatively. Although there is a wide range (2.5-9.0 oz) of pouch sizes at 1 year, there is no significant difference in excess weight loss between the smaller and larger pouches. CONCLUSIONS: The pouches enlarge by the orderly process of hyperplasia. Within the 2.5-9 oz volume variation, the pouch volume alone is not a predictor of weight loss. Rather, how the patient uses the pouch/tool, in addition to the other behavior modifications, determines the degree of weight loss. This data strongly suggests that the surgeon's understanding of and teaching of the optimal use of the pouch/tool may be more important than previously thought.