Risk Factors for Porto-Mesenteric Venous Thrombosis After Laparoscopic Sleeve Gastrectomy: a Matched Case-Control Study.

INTRODUCTION: Porto-mesenteric venous thrombosis (PMVT) is a rare but potentially life-threatening complication following laparoscopic sleeve gastrectomy (LSG). Although PMVT has been reported in patients without classical thrombotic risk factors, predictors in the post-LSG setting remain poorly defined. This study aimed to identify patient-level risk factors associated with PMVT after LSG. METHODS: We conducted a retrospective matched case–control study including patients who developed PMVT within 90 days after LSG between 2014 and 2025. Cases were matched to controls without PMVT by age, sex, year of surgery, and surgical center in a 1:4 ratio. Conditional logistic regression was used to evaluate associations between clinical, metabolic, and perioperative factors and PMVT. RESULTS: Thirty-eight PMVT cases and 152 matched controls were analyzed. Metabolic dysfunction–associated steatotic liver disease (MASLD) was significantly more prevalent among PMVT cases. In multivariate conditional logistic regression, MASLD was independently associated with increased odds of PMVT (adjusted odds ratio 2.95; 95% confidence interval 1.03–8.47; p = 0.044). Most PMVT events occurred within 30 days of surgery (92.1%). Abdominal pain was the most common presenting symptom, and combined portal and superior mesenteric vein thrombosis was the predominant radiologic pattern. CONCLUSION: PMVT after LSG is uncommon but clinically significant and occurs predominantly in the early postoperative period. MASLD was independently associated with PMVT, suggesting that hepatic metabolic dysfunction may be linked to increased postoperative thrombotic vulnerability. Recognition of this association may support heightened clinical vigilance following LSG.