Idiopathic myointimal hyperplasia of the mesenteric veins: A systematic review and individual patient data regression analysis

Background and Aim: Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) is an uncommon cause of colonic ischemia for which surgical treatment is typically curative. We describe clinical, radiologic, and endoscopic findings in IMHMV patients to provide clinicians with a framework for pre-surgical identification of this rare disease. Methods: We performed a systematic review of seven databases for IMHMV cases and identified additional cases from Yale New Haven Hospital records. To identify features specifically associated with colonic ischemia due to IMHMV, we performed multivariate logistic regression analysis incorporating data from a large cohort of patients with biopsy-proven ischemic colitis. Results: A total of 124 patients with IMHMV were identified (80% male, mean age 53 years, 56% Caucasian). Presenting symptoms were most commonly abdominal pain (86%) and diarrhea (68%). The most affected areas were the sigmoid colon (91%) and rectum (61%). Complications associated with diagnostic delay occurred in 29% of patients. Radiologic vascular abnormalities including non-opacification of the inferior mesenteric vein were observed in 35% of patients. Of the patients, 97% underwent curative surgical resection. Compared with non-IMHMV colonic ischemia, IMHMV was significantly associated with younger age, male sex, absence of rectal bleeding on presentation, rectal involvement, and mucosal ulcerations on endoscopy. Conclusion: IMHMV is a rare, underreported cause of colonic ischemia that predominantly involves the rectosigmoid. Our findings suggest younger age, rectal involvement, and absence of rectal bleeding as clinical features to help identify select patients presenting with colonic ischemia as having higher likelihood of IMHMV and therefore consideration of upfront surgical management.