Idiopathic Myointimal Hyperplasia Of The Mesenteric Veins Research Articles

Preoperatively Confirmed Idiopathic Myointimal Hyperplasia of the Mesenteric Veins: A Case Report

Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) is a rare cause of colonic ischemia. First documented in the literature in 1991, this condition has remained exceedingly rare, with only a limited number of case reports since its initial mention. It involves proliferation of intimal smooth muscle within the mesenteric veins, resulting in colonic ischemia due to venous constriction and non-thrombotic occlusion. Patients experience a prolonged clinical course and adverse outcomes due to its rarity and nonspecific symptoms. The definitive diagnosis is typically confirmed after surgical resection of the affected colon, as initial biopsies are not deep enough to confirm the diagnosis. Histological examination of these biopsies reveals arteriolization of capillaries, subendothelial hyaline deposits, and fibrin thrombi. We present a case of a patient with a one-year history of diarrhea and abdominal pain. Biopsy samples obtained during colonoscopy showed colitis and proliferation of muscularized capillaries, consistent with IMHMV, prior to colon resection. The patient ultimately underwent laparoscopic total abdominal colectomy to the distal one-third of the rectum with end ileostomy. IMHMV is commonly treated surgically and mismanagement of this condition involving corticosteroids and immunomodulatory agents may result in unfavorable outcomes. This case report is one of the few cases of IMHMV diagnosed preoperatively within existing literature, which highlights a rare etiology of nonspecific colitis, emphasizing the critical divergence in its management approach.

Idiopathic myointimal hyperplasia: An unusual cause of colonic ischemia

Introduction: Ischemic colitis is a commonly encountered surgical condition with a variety of causes, including atrial fibrillation, atherosclerosis, hypoperfusion, vasculitis, and rarely drug causes such as methamphetamines. Case Report: Here we describe the case of a 47-year-old male who presented with non-specific abdominal symptoms. He was initially treated for severe ulcerative colitis (UC), before biopsies were re-reviewed and specimens showed changes pathognomic for idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV). He underwent surgical resection of affected segments and recovered well. Conclusion: This case illustrates a rare diagnosis presenting with common symptoms and the importance of considering this diagnosis in patients not responding to usual treatment.

S36 Idiopathic Myointimal Hyperplasia of the Mesenteric Veins a Rare Mimic of Inflammatory Bowel Disease: A Systematic Review

Background: Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) is an extremely rare non-thrombotic mesenteric veno-occlusive disease. IMHMV manifests with non-specific symptoms mimicking inflammatory bowel disease. Therefore, patients are initially misdiagnosed with and treated for acute severe ulcerative colitis. However, given its rarity, the optimal surgical intervention remain undefined. Hence, this study aimed to perform a systematic review to assess the various surgical procedures and associated outcomes for patients with IMHMV. Methods: We conducted a systematic search for articles reporting patients with IMHMV in MEDLINE, EMBASE, Cinahl, Scopus, Web of Science, and Cochrane Library. The search was conducted from 1946 to April 2022. We also retrospectively analyzed IMHMV cases managed at our institution until April 2022. The risk of bias of included studies was evaluated with a modified tool proposed by Murad et al A narrative synthesis of included studies was provided. Results: The search strategy retrieved 703 references, of which 54 studies were included. Fifty were case reports and 4 were case series. A total of 88 patients with IMHMV were included. Most patients (82%) were male, with a mean age of 56.6 years old (range: 13–83 years). The median follow-up was 24 months (range: 1 – 144 months) with surveillance performed primarily via endoscopic evaluation. Abdominal pain and diarrhea were the most frequent presenting symptoms. Most reports described involvement of the rectum and sigmoid colon (81%). Only 6 (8%) IMHMV cases were suspected preoperatively and underwent elective surgery. The majority (99%) of patients initially managed medically eventually required surgery. Only 1 patient sustained symptomatic resolution with medical management. The most common surgical procedures were Hartmann’s procedure (24%) and segmental colectomy (19%). Secondary anastomoses were reported in 10 cases and performed after endoscopic confirmation absence of disease between 2 – 10 months. A total of 3 (3%) patients underwent either total proctocolectomy or total abdominal colectomy/completion proctectomy with IPAA formation. Four (5%) complications were reported and these were noted to occur when the involved portion of the bowel was the ileum, ascending colon, or transverse colon. Nearly all (99%) patients achieved IMHMV resolution with primary surgical intervention. Only 1 (1%) patient required a completion total colectomy following IMHMV recurrence. The overall risk of bias was judged to be low in 4 studies, unclear in 19 studies, and high in 31 studies. Conclusion(s): IMHMV is a rare pathology typically diagnosed following surgical resection with only a few cases suspected preoperatively. Patients are oftentimes initially misdiagnosed with acute severe ulcerative colitis, because of the similarities in clinical manifestations. IMHMV is typically treated medically but surgical resection is nearly always needed due to failure of medical therapy. Surgical resection via Hartmann’s procedure or segmental colectomy have been shown to be safe and effective with a low risk of complications and recurrence. As a rare disease, more evidence is required to optimally inform surgical decision-making, but it appears that sparing the unaffected colon is reasonable. The creation of a national or global collaborative database would be useful to help optimize recommendations for patients with this rare disease.

S74 IMHMV: A Rare IBD Mimicker Successfully Treated With Hyperbaric Oxygen Therapy

Background: Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) is a rare cause of chronic intestinal ischemia. It is believed to be related to nonthrombotic occlusion of the small to medium sized mesenteric veins due to intimal smooth muscle proliferation. The etiology, pathophysiology and diagnostic criteria are poorly understood and often results in delayed diagnosis. IMHMV is a mimicker of inflammatory bowel disease (IBD) with symptoms including abdominal pain, bloody diarrhea, and weight loss as well as endoscopic evaluation shows ulcerations, edema, and friability. Surgical resection is usually curative. Case presentation: A 50-year-old man with history of kidney transplant on immunosuppressive medications, presented with 2 months’ history of increased urgency, tenesmus and severe rectal pain. Workup showed inflammatory changes in the rectosigmoid colon on CT abdomen-pelvis. Colonoscopy demonstrated a segmental area in the sigmoid colon with severely ulcerated mucosa. He was diagnosed with IMHMV and treated with off-label hyperbaric oxygen therapy (HBOT) with complete resolution of his symptoms and colonic ischemia. Conclusion: IMHMV is a rare mimicker of IBD that requires surgical resection. However, this is the first case in the literature that showed successful treatment of IMHMV with HBOT.

S188 Idiopathic Myointimal Hyperplasia of Mesenteric Veins: A Systematic Review and Individual Patient Regression Analysis

Introduction: Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) is an uncommon cause of colonic ischemia for which surgical treatment is recommended. We describe the clinical, radiologic and endoscopic findings in IMHMV patients to provide clinicians with a framework for the identification of this rare disease. Methods: We performed a systematic review of seven databases for cases of IMHMV 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, well-characterized multicenter cohort of biopsy-proven ischemic colitis (n=923). Results: A total of 123 patients with IMHMV were identified from 58 publications and 3 unpublished cases at Yale New Haven Hospital (80% male, mean age 53, 56% Caucasian). Symptoms at presentation were most commonly abdominal pain (87%) and diarrhea (67%). The most affected areas were the sigmoid colon (89%) and rectum (66%). Median time from symptom onset to diagnosis was 4 months. Complications, including obstruction and perforation due to diagnostic delay occurred in 33% of patients. The most common radiologic feature was thickening of the affected segment of colon (97%). Anatomic vascular abnormalities including non-opacification of the inferior mesenteric vein were observed in 38% of patients. 97% of patients ultimately underwent curative segmental colectomy. Mean follow-up time was 23.6 months. Compared to biopsy-proven non-IMHMV colonic ischemia, IMHMV was significantly associated with younger age (p=0.010), male sex (p=0.002), rectal involvement on imaging (p=0.027) and on endoscopic evaluation (p=0.004), mucosal ulcerations on endoscopy (p=0.049) and absence of rectal bleeding on presentation (p< 0.001) (Table). Conclusion: IMHMV is a rare, underreported cause of colonic ischemia that predominantly involves the left colon. Using the largest IMHMV cohort to date and comparing to a multicenter cohort of patients with ischemic colitis, we identify clinical, endoscopic, and radiologic characteristics of this entity. 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. Table 1. - Clinical, endoscopic, and radiologic findings associated with IMHMV associated colonic ischemia Variable # patients IMHMV # patients Non-IMHMV P value Demographics Age 85 55.5 (17.0) 922 69.5 (13.2) < 0.001 Male sex 85 78.8% (67) 918 28.7% (265) < 0.001 Clinical Presentation Abdominal pain 85 84.7% (72) 918 82.6% (758) 0.764 Rectal bleeding 85 57.6% (49) 913 76.2% (696) < 0.001 Pain without bleeding 85 35.3% (30) 911 22.7% (207) 0.011 Bleeding without pain 85 8.2% (7) 911 18.2% (166) 0.017 Non-bloody diarrhea 85 24.7% (21) 911 11.0% (100) < 0.001 Clinical Comorbidities Hypertension 61 21.3% (13) 921 75.1% (692) < 0.001 Diabetes mellitus 61 13.1% (8) 921 30.0% (276) 0.005 Stroke 61 4.9% (3) 920 10.8% (99) 0.193 Hypercoagulability 61 6.6% (4) 768 1.0% (8) 0.008 Multivariate logistic regression Variable aOR 95% CI P value Age, per year 0.941 0.919 – 0.964 0.010 Sex (Male) 10.10 4.71 – 21.67 0.002 Rectal bleeding on presentation 0.006 0.001 – 0.025 < 0.001 Non-bloody diarrhea on presentation 1.46 0.60 – 3.55 0.673 Diabetes mellitus 0.569 0.249 – 1.350 0.494 Rectal involvement on imaging 6.71 2.84 – 15.85 0.027 Right-sided involvement on endoscopy 0.620 0.213 – 1.806 0.655 Rectal involvement on endoscopy 12.61 5.22 – 30.51 0.004 Mucosal ulcerations on endoscopy 4.06 1.99 – 8.25 0.049 Baseline characteristics and regression analysis of IMHMV and non-IMHMV patients included in the final multivariate model. Number of patients included in the analysis are indicated. Continuous variables presented as mean and standard deviation. Categorical variables are presented as proportion and number of individuals. aOR = adjusted odds ratio. 95% CI = 95% confidence interval.

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.

Idiopathic myointimal hyperplasia is a distinct cause of chronic colon ischaemia.

Colon ischaemia (CI) is most commonly an acute and reversible manifestation of a transient, non-occlusive decrease of blood flow in the colonic microvasculature. Irreversible complications are uncommon and the progression to chronic CI remains controversial. Our objective was to identify cases of chronic CI and assess for distinct clinicopathological features. A retrospective review was performed of CI patients having symptom chronicity of ≥1month and ischaemic histology at our institution from 1994 to 2015. Demographic, clinical, endoscopic, radiological, pathological and outcome variables were abstracted. Histological evaluation was performed by two gastrointestinal pathologists. Fifteen patients (n=9; 67% men) with a median age of 65years (range 22-88) were identified. The most common presenting symptoms were diarrhoea and abdominal pain (n=6, 86%; n=5, 71%, respectively). The typical endoscopic appearance was segmental ulceration of the sigmoid colon (n=6, 75%). Vascular imaging showed patent mesenteric vessels in all patients. Histopathological evaluation revealed venous intimal hyperplasia consistent with idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) in eight patients; the remainder showed non-specific ulceration and fibrosis. Surgical resection was performed in seven IMHMV patients, resulting in symptom resolution. On re-review of pre-resection biopsies, all IMHMV patients had characteristic changes of hyperplastic, thick-walled, hyalinized vessels in the lamina propria. IMHMV is a unique histopathological entity causing chronic CI. The small vessel histological changes in IMHMV are distinctive in colonic resections and undetectable by routine vascular imaging. Preoperative diagnosis of IMHMV is possible with endoscopic biopsy and segmental colon resection is curative.

Idiopathic Myointimal Hyperplasia of the Mesenteric Veins (IMHMV): A Challenging Case of Colitis in a Young Man

A 25 year-old male presented for evaluation of six weeks of diarrhea and abdominal pain. He had progressive worsening of abdominal pain, poor oral intake, weight loss (30 pounds) and 10-20 daily bowel movements that were predominantly mucous and blood. Initial work-up at an outside hospital revealed wall thickening of the descending colon to the rectum on CT scan and two flexible sigmoidoscopies with diffuse congestive erythema, ulceration and necrosis from the sigmoid colon to rectum. Upon referral to our medical center, work-up included a repeated flexible sigmoidoscopy that showed an area of congested, friable, dusky mucosa with overlying exudate in the recto-sigmoid colon, which appeared ischemic. Endoscopic biopsies were most consistent with ischemic colitis, with no evidence of CMV. Extensive infectious work-up (C. difficile, stool culture, ova and parasites, CMV, syphilis, HSV, gonorrhea, chlamydia) and clotting factors all were normal. CT angiography showed normal mesenteric vasculature. A diagnosis of IMHMV was suspected, and the patient underwent a laparoscopic sigmoid colectomy with end colostomy and mucous fistula. Gross sectioning revealed multiple blood vessels with thickened vessel walls. Microscopic examination revealed occlusive vasculopathy with prominent intimal hyperplasia of small to medium-sized mesenteric veins with abscess, necrosis and serositis, confirming the diagnosis of idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV). IMHMV is a rare cause of colitis that afflicts predominantly men of young to middle age. It has been reported in sixteen published reports in the literature. The presentation is nonspecific, with abdominal pain, diarrhea, hematochezia and mucous in stool. The clinical presentation alone can lead to a diagnostic dilemma, as many components are similar to other causes of colitis. It is often mistaken initially for inflammatory bowel disease given the demographic of the patient, yet endoscopic appearance can suggest ischemia and biopsies are frequently more consistent with ischemic colitis than inflammatory bowel disease. Generally, it requires pathological evaluation of a surgical resection specimen to confirm the diagnosis. Six months after his operation, our patient is doing well. His symptoms have resolved completely. A subsequent endoscopic evaluation was essentially normal with rectal biopsies showing mild architectural distortion. He is currently being considered for take-down of his colostomy, which has never been reported in the literature before.