Radiological and clinical findings of idiopathic myointimal hyperplasia of mesenteric veins: Case report

CT findings in idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) and comparison to other colitides

PURPOSE

The purpose of this study is to determine computed tomography (CT) findings that aid in differentiating idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) from other colitides.

METHODS

Retrospective review of histiologic proven cases of IMHMV (n = 12) with contrast enhanced CT (n = 11) and/or computed tomography angiography (CTA) (n = 9) exams. Control groups comprised of CT of infectious colitis (n = 13), CT of inflammatory bowel disease (IBD) (n = 12), and CTA of other colitides (n = 13). CT exams reviewed by 2 blinded gastrointestinal radiologists for maximum bowel wall thickness, enhancement pattern, decreased bowel wall enhancement, submucosal attenuation value, presence and location of IMV occlusion, peripheral mesenteric venous occlusion, dilated pericolonic veins, subjective IMA dilation, maximum IMA diameter, maximum peripheral IMA branch diameter, ascites, and mesenteric edema. Presence of early filling veins was an additional finding evaluated on CTA exams.

RESULTS

Statistically significant CT findings of IMHMV compared to control groups included greater maximum bowel wall thickness, decreased bowel enhancement, IMV occlusion, and peripheral mesenteric venous occlusion (p < 0.05). Dilated pericolonic veins were seen more frequently in IMHMV compared to the infectious colitis group (64% versus 15%, p = 0.02). Additional statistically significant finding on CTA included early filling veins in IMHMV compared to the CTA control group (100% versus 46%, p = 0.008).

CONCLUSION

IMHMV is a rare chronic non-thrombotic ischemia predominantly involving the rectosigmoid colon. CT features that may aid in differentiating IMHMV from other causes of left-sided colitis include marked bowel wall thickening with decreased enhancement, IMV and peripheral mesenteric venous occlusion or tapering, and early filling of dilated veins on CTA.

Idiopathic myointimal hyperplasia of the mesenteric veins: A systematic review of surgical management

BACKGROUND

Idiopathic myointimal hyperplasia of the mesenteric veins is an extremely rare non-thrombotic mesenteric veno-occlusive disease. The management of idiopathic myointimal hyperplasia of the mesenteric veins is not well-established, and although surgery is the mainstay of treatment, the optimal operation remains unclear. Therefore, we aimed to perform a systematic review to assess the various surgical procedures and associated outcomes for patients with idiopathic myointimal hyperplasia of the mesenteric veins.

METHODS

A systematic search for articles published from 1946 to April 2022 in MEDLINE, EMBASE, Cinahl, Scopus, Web of Science, and Cochrane Library databases is reported. In addition, we report 4 cases of idiopathic myointimal hyperplasia of the mesenteric veins managed at our institution until March 2023.

RESULTS

A total of 53 studies and 88 patients with idiopathic myointimal hyperplasia of the mesenteric veins were included. Most (82%) were male patients, with a mean age of 56.6 years old. The majority (99%) of patients required surgery. Most reports described the involvement of the rectum and sigmoid colon (81%). The most common surgical procedures were Hartmann's procedure (24%) and segmental colectomy (19%); completion proctectomy with ileal pouch-anal anastomosis was performed in 3 (3.4%) cases. In 6 (6.8%) cases, idiopathic myointimal hyperplasia of the mesenteric veins was suspected preoperatively and managed with elective surgery. Four (4.5%) complications were reported. Nearly all (99%) patients achieved remission with surgical intervention.

CONCLUSION

Idiopathic myointimal hyperplasia of the mesenteric veins is a rare pathologic entity infrequently suspected preoperatively and typically diagnosed after surgical resection. Surgical resection with Hartmann's procedure or segmental colectomy was most commonly performed, with completion proctectomy and ileal pouch-anal anastomosis reserved for cases of extensive rectal involvement. Surgical resection was safe and effective, with a low risk of complications and recurrence. Surgical decision-making should be based on the extent of the disease at the time of presentation.

Ischemic Colitis Due to Idiopathic Myointimal Hyperplasia of the Mesenteric Veins

Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) is a rare and poorly understood noninflammatory ischemic colitis. First reported by Genta and Haggitt in 1991, the disease typically presents with chronic abdominal pain, weight loss, and diarrhea with or without hematochezia in middle-aged men. IMHMV is frequently misdiagnosed as an inflammatory bowel disease. The pathophysiology of IMHMV involves the proliferation of the intimal smooth muscle in mesenteric veins leading to bowel ischemia. The etiology of this process remains unknown. There are no good medical therapies for IMHMV, and surgical resection, a curative intervention, is typically required to make the diagnosis. We present the case of a 66-year-old man with IMHMV diagnosed with endoscopic biopsies.

Imaging of Bowel Ischemia: An Update, From the AJR Special Series on Emergency Radiology

Acute mesenteric ischemia is a life-threatening condition that results from abrupt reduction in or cessation of blood flow to the bowel. Characterized by nonspecific abdominal symptoms, mesenteric ischemia is infrequently encountered and commonly misdiagnosed, with potentially catastrophic consequences. Prompt clinical diagnosis and early implementation of therapeutic interventions are critical to improving patient outcomes. Because cross-sectional imaging plays a key role in the diagnosis of mesenteric ischemia, radiologists must be familiar with the varied imaging manifestations of intestinal ischemia. Thus, the objectives of this article are to review the various types and common causes of mesenteric ischemia and to describe its spectrum of multimodality imaging findings, with special attention to novel imaging techniques and emerging diagnoses.

Idiopathic myointimal hyperplasia of mesenteric veins depicted by barium enema examination, and conventional and magnifying colonoscopy

A 71-year-old man was admitted to our institution complaining of abdominal pain and constipation. Barium enema examination revealed narrowing, cobble stoning, and longitudinal ulcerations in the sigmoid colon and upper rectum. Conventional colonoscopy, magnifying narrow-band imaging endoscopy, and magnifying chromoendoscopy revealed edematous mucosa, longitudinal ulcerations with luminal narrowing, and multiple pseudopolyps. The histologic examination of the biopsy specimens showed thick-walled (arterialized) capillaries and subendothelial fibrin deposits in the mucosa and submucosa. Based on a preoperative diagnosis of idiopathic myointimal hyperplasia of mesenteric veins (IMHMV), he underwent a laparoscopic resection of the sigmoid colon and upper rectum. The histologic examination of the resected specimens showed marked proliferation of venous walls with marked myointimal thickening and luminal occlusion from the submucosa to the mesentery throughout the entire resected tissue section. The final diagnosis was IMHMV.

Idiopathic Myointimal Hyperplasia of the Mesenteric Veins: A Case Report and Scoping Review of Previously Reported Cases From Clinical Features to Treatment

Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) is a rare and poorly understood disease. It is characterized by non-thrombotic and non-inflammatory occlusion of the mesenteric veins secondary to intimal smooth muscle hyperplasia. The etiology of IMHMV is unknown, and its clinical presentations include abdominal pain, bloody diarrhea, and weight loss. IMHMV is commonly mistaken for inflammatory bowel disease because of the similarity in symptoms and endoscopic findings. Herein, we report the case of a 64-year-old man with IMHMV and present an overview of all reported cases of IMHMV. In this review, we analyzed 70 cases to summarize the etiology, clinical manifestations, and diagnosis of IMHMV and hope to raise clinicians' awareness of this entity.