Counting Limb Length Ratios in Roux-en-Y Gastric Bypass: A Demonstration of Safety and Feasibility Using a 25-Patient Case Series in a High-Volume Academic Center

<b>Background:</b> Despite being one of the most performed bariatric procedures, there is no consensus regarding optimal limb lengths for Roux-en-Y gastric bypass (RYGB), which may impact weight loss and obesity-related comorbidity resolution. We hypothesize that a ratio-adjusted small bowel to Roux and BP limb lengths in RYGB results in superior outcomes. <b>Objectives:</b> This study aims to define total intestinal length (TIL) and the feasibility of its intraoperative measurement during RYGB. The findings will serve as a foundation for a subsequent randomized trial evaluating different limb length ratios and their effect on postoperative outcomes. <b>Setting:</b> This was a single-center prospective cohort study conducted at Cleveland Clinic Foundation-Main Campus, a tertiary referral center in the United States. <b>Methods:</b> Between January and June 2023, 25 patients with BMI > 40 undergoing RYGB were enrolled. Total small bowel length was measured intraoperatively, and feasibility of measurement was assessed. Patient outcomes, including total weight loss, 30-day complications, and comorbidities at 1 year were captured. <b>Results:</b> Mean preoperative BMI was 47.6 ± 8.0 kg/m². Mean total small bowel length was 592 ± 93.3 cm, with a mean biliopancreatic (BP) limb length of 109 ± 29 cm (18.86% ± 5.84 of total length) and Roux limb length of 103 ± 15 cm (17.71% ± 3.06 of total length). Measurement added an average of 11.5 min to operative time. Measurement feasibility was rated as "moderate" or easier in 80% of cases. One-year postoperative outcomes included a mean total weight loss of 31% and significant reductions in antihypertensive and anti-diabetic medication use. <b>Conclusions:</b> Total small bowel length measurement during RYGB is safe and feasible. High variability in bowel length was observed, with no significant correlation to demographic factors. Establishing individualized limb length ratios may improve weight loss outcomes and comorbidity resolution. Further studies are warranted to evaluate the impact of tailored limb length strategies.