Long-Term Outcome of Proximal Versus Very-Very Long Limb Roux-en-Y Gastric Bypass: the Roux-Limb to Common Channel Ratio Determines the Long-Term Weight Loss.

Abstract

The influence of the Roux limb (RL) length on weight loss in Roux-en-Y (RYGB)-type gastric bypass procedures is still unclear. This study analyzes the true impact of RL length by comparing the long-term outcomes of proximal RYGB (PRYGB) and very-very long limb RYGB (VVLL-RYGB). RL length in PRYGB was 150cm. In VVLL-RYGB, common channel length was 100cm. In both groups, biliopancreatic limbs measured 50-60cm, resulting in equal total alimentary limb lengths. To adjust for pre-operative differences between groups, and to predict the long-term outcome, a mixed model analysis was performed. Two hundred thirty-two patients with VVLL-RYGB (73.7% female, mean age 41.1 ± 10years, initial BMI 45.8 ± 6.3kg/m2) and 223 with PRYGB (83.9% female, mean age 38.5 ± 11years, initial BMI 42.9 ± 4.9kg/m2) were included. Mean follow-up was 9.4 ± 4years in VVLL-RYGB and 5.3 ± 1.9years in PRYGB. After 5years, mean BMI reduction was 15.7 ± 5.9kg/m2 in VVLL-RYGB and 11.9 ± 4.1kg/m2 in PRYGB (p < 0.001), and mean %EWL was 78.3 ± 23.1% and 70.2 ± 23.7% (p = 0.002) with a follow-up rate of 78% and 75.9%, respectively. The mixed model analysis showed a significantly higher weight rebound after PRYGB. Frequency of revisional surgery (i.e., limb length alteration, pouch banding) was similar between VVLL-RYGB and PRYGB (25 vs. 29 revisions, p = 0.463). The VVLL-RYGB has a significantly higher long-term BMI reduction and a significantly lower weight rebound. The length of the Roux limb significantly influences long-term outcome.