Management of portomesenteric vein thrombosis following bariatric surgery

Portomesenteric venous thrombosis (PMVT) is a rare complication of bariatric surgery that can lead to cavernous transformation of the portal vein. There are no established treatment algorithms regarding anticoagulation (AC) only vs. catheter-directed thrombolysis in this population.

Medical records at 4 urban bariatric surgery centers were queried for patients diagnosed with PMVT between 2012 and 2025. Patient characteristics, perioperative details, imaging at PMVT diagnosis, treatment course, and follow-up imaging were reviewed. Fisher's exact testing was conducted to identify correlations between extent of thrombosis, treatment course (anticoagulation vs. interventional radiology [IR] thrombolysis), and the outcome of cavernous transformation.

71 patients were diagnosed with PMVT following bariatric surgery (68 LSG, 3 RYGB) at 4 centers between 2012 and 2025. Median time from surgery to PMVT diagnosis was 13 days. Three patients (4%) required reoperation for small bowel resection, of whom 2 underwent open thrombectomy and 1 underwent subsequent IR thrombolysis. Of the remaining patients, 6/68 (9%) underwent IR catheter-directed thrombolysis, and 62/68 (91%) received AC only. Of 53 patients with long-term data, 18 (34%) developed cavernous transformation. Among patients who had a main portal vein + intrahepatic portal vein + inflow (superior mesenteric vein or splenic vein) thrombosis, treatment with AC only was strongly associated with cavernous transformation (13/17, 76%) vs IR (1/5, 20%, p < 0.05). There were no deaths related to PMVT.

In this largest known case series of postbariatric surgery PMVT treated with anticoagulation vs. IR, we found that the PMVT clot pattern with the highest risk of developing cavernous transformation was the extensive type involving the main portal vein, an intrahepatic portal vein, and an inflow vein, whether the main portal vein clot was occlusive or nonocclusive. Early IR intervention was associated with decreased cavernous transformation.