Unforeseen pathological and anatomical findings during primary metabolic and bariatric surgery – a retrospective cohort study and review of the literature

The prevalence of morbid obesity has surpassed our previous projections and has become a real pandemic. An increasing number of patients are undergoing metabolic bariatric surgery (MBS), and a small but significant proportion of them present with unexpected pathological or anatomical findings that pose intraoperative challenges for bariatric surgeons. A retrospective analysis of our prospectively maintained database revealed that 46 of the 2387 patients (1.9%) who underwent primary MBS between June 2010 and April 2024 presented with previously undiagnosed pathological or anatomical findings during their operation. The patients’ characteristics and surgical outcomes were reviewed, and extensive literature research was conducted to establish the incidence of these findings. The incidence of gastrointestinal stromal tumors (GISTs) was 0.54%, with > 60% of cases presenting on the gastric fundus. R0 resection was considered in all patients. Seven patients (0.3%) had liver cirrhosis, which was confirmed intraoperatively through surgical biopsy. Large hiatal hernias incidence was 0.8% and all required crural approximation. The incidence of benign lesions was 0.2%, and incidental primary or disseminated malignancies accounted for only 0.1% of the cases. Bariatric surgeons should be cognizant of potential intraoperative pathological or anatomical abnormalities, and this paper provides systematic and plausible strategies for managing these challenging situations.