Background and objectives: We classified the extent of mesenteric mass (MM) involvement that predicts challenging mesenteric lymph node dissection (mLND) by minimally invasive surgery (MIS) for ileal neuroendocrine tumors (i-NETs).
Methods: Patients who underwent surgery for i-NETs were retrospectively reviewed. MM involvement was classified as region-0: no MM; region-1: >2 cm from the origins of the ileocolic artery/vein; region-2: ≤2 cm from the origins; and region-3: more proximal superior mesenteric artery/vein. Logistic regression analysis was used to evaluate the predictive value of MM regions for gross positive mesenteric margin (mR2) and/or conversion among the MIS cohort. The open surgery cohort was used as a reference for mR2 rates.
Results: Of 108 patients, 83 patients (77%) underwent MIS. MMs in region-2 and region-3 were independent risk factors for mR2 and/or conversion (odds ratio [95% confidence interval]: 4.25 [1.17-16.4] and 8.51 × 107 [11.0-], respectively, against regions-0 and 1]. mR2 rates of MIS and open surgery cohorts per region did not differ significantly (4% and 7% for regions-0 and 1; 17% and 25% for region-2; and 100% and 83% for region-3).
Conclusions: The novel stratification of MM regions was predictive of challenging mLND by MIS. Surgeons should have a low threshold for conversion for MMs in proximal regions.
Keywords: conversion; mesenteric lymph node dissection; mesenteric mass; minimally invasive surgery.
© 2020 Wiley Periodicals, Inc.