MRI of pouch-related fistulas in ulcerative colitis after restorative proctocolectomy

ACR Appropriateness Criteria® Anorectal Disease

This review summarizes the relevant literature for the selection of the initial imaging in 4 clinical scenarios in patients with suspected inflammatory disease or postoperative complication of the anorectum. These clinical scenarios include suspected perianal fistula or abscess; rectovesicular or rectovaginal fistula; proctitis or pouchitis; and suspected complication following proctectomy, coloproctectomy, or colectomy with a pouch or other anastomosis. The appropriateness of imaging modalities as they apply to each clinical scenario is rated as usually appropriate, may be appropriate, and usually not appropriate to assist the selection of the most appropriate imaging modality in the corresponding clinical scenarios of anorectal disease. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

MRI of perianal fistulas: bridging the radiological-surgical divide

Perianal fistula is a clinical entity with multiple surgical treatment options. Recently, magnetic resonance imaging (MRI) has emerged as an important imaging modality in the management of perianal fistulas. It provides accurate description of the fistula within the anal canal in relation to the sphincter complex and other pelvic floor structures as well as the associated complications such as abscess. By understanding the surgical viewpoint, the appearance of perianal fistulas, associated complications, and post-treatment findings of commonly used surgical interventions can more accurately be interpreted to aid clinicians. The objective of the article is to review MRI indications and findings, radiological versus surgical classification schemes, and surgical treatment options for perianal fistulas.

Evaluating pouch problems

IPAA is a technically demanding procedure that requires appropriate skills and expertise. Adverse sequelae of IPAA are common. Accurate diagnosis and classification of pouch disorders and associated complications are important for proper management and prognosis. Based on presenting symptoms, appropriate and combined diagnostic modalities should apply. A multidisciplinary approach involving gastroenterologists, colorectal surgeons, gastrointestinal pathologists, and gastrointestinal radiologists is advocated for diagnosis and treatment of pouch disorders.

Evaluation of endoscopic and imaging modalities in the diagnosis of structural disorders of the ileal pouch

BACKGROUND

Computerized tomography enterography (CTE), gastrograffin enema (GGE), magnetic resonance imaging (MRI), and pouch endoscopy (PES) have commonly been used to assess ileal pouch disorders. However, their diagnostic utility has not been systematically evaluated. The aims of this study were to compare these imaging techniques to each other and to optimize diagnosis of pouch disorders by using a combination of these diagnostic modalities.

METHODS

Clinical data of patients from the Pouchitis Clinic from 2003 to 2008 who had a PES and at least 1 additional imaging modalities (CTE, GGE, or MRI) used for evaluation of ileal pouch disorders were retrospectively evaluated. We analyzed the accuracy, sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) with which these tests were able diagnose pouch inlet and distal small bowel and pouch outlet strictures, pouch fistulas, sinuses, and leaks. Subsequently, accuracy was recalculated by combining 2 imaging modalities to see if this could enhance accuracy.

RESULTS

A total of 66 patients underwent evaluation with PES and 1 other imaging modality as follows: PES + CTE (n = 23), PES + GGE (n = 34), and PES + MRI (n = 26). The mean age was 41.5 +/- 14.5 years, with 28 being female (42.4%). Sixty patients (90.9%) had J pouches and 59 (89.4%) had a preoperative diagnosis of ulcerative colitis. Overall, CTE, GGE, MRI, and PES all had reasonable accuracy for the diagnosis of small bowel and inlet strictures (73.9%-95.4%), outlet strictures (87.9%-92.3%), fistula (76.9%-84.8%), sinus (68.0%-93.9%), and pouch leak (83-93.9%). CTE had the lowest accuracy for small bowel and inlet strictures (73.9%) and MRI had the lowest accuracy for pouch sinus (68.0%). Combining 2 imaging tests can increase the accuracy of diagnosis to 100% for strictures, fistulas, sinus, and pouch leaks.

CONCLUSIONS

CTE, GGE, MRI, and PES offer complementary information on disorders of the pouch and the combination of these tests increases diagnostic accuracy for complex cases.

MRI of complicated pouchitis

OBJECTIVE

The purpose of this study is to assess the ability of MRI to identify the presence of inflammation related to the pouch reservoir in symptomatic patients with an ileal pouch-anal anastomosis who present with clinically suspected complicated pouchitis.

CONCLUSION

Initial results suggest that MRI should be considered in patients who have undergone ileal pouch-anal anastomosis and present a clinical impression of complicated pouchitis. MRI showed abnormalities consistent with complicated pouchitis in seven of nine examinations, with findings including pouch wall thickening, abnormal wall enhancement, peripouch fluid collection, sinus and fistula tract formation, lymphadenopathy, and peripouch stranding and fatty proliferation. MRI findings of complicated pouchitis should raise the suspicion of Crohn's disease and should prompt further investigation.

Systematic review: the management of pouchitis

Pouchitis is the most common complication following proctocolectomy and ileal pouch-anal anastomosis in patients with ulcerative colitis. We aim at discussing relevant information on epidemiology, clinical features, risk factors, diagnostic testing, differential diagnosis and treatment of this idiopathic inflammatory condition. A computerized search of PubMed was performed with the search term 'pouchitis', limited to English papers on humans. This strategy identified 514 references. Relevant articles were selected from this list. In addition, the reference list for each of the selected articles was reviewed to identify any additional references. Pouchitis occurs in up to 60% of patients after ileal pouch-anal anastomosis for ulcerative colitis, and has characteristic clinical, endoscopic and histological features. The most important test for diagnosis is pouch endoscopy with biopsy. Antibiotics remain the mainstay of treatment, and other options are discussed for those patients who are refractory to antibiotic therapy.

Ileal pouch-anal anastomosis-vaginal fistula: a review

BACKGROUND

Fistula between an ileal pouch and the vagina is an uncommon complication of ileal pouch-anal anastomosis. Its optimal management has not been determined because of its low incidence.

METHODS

The literature describing such fistulas was reviewed to determine the incidence, cause, and appropriate investigation and repair of these lesions. A literature search was performed with the PubMed, MEDLINE, and EMBASE databases. Through this search we located English-language articles from 1970 to 2003 on pouch-vaginal fistulas following ileal pouch-anal anastomosis. References from these articles were searched manually for further references.

RESULTS AND CONCLUSION

Pouch-vaginal fistula occurs in 6.3 (range, 3.3-15.8) percent of female patients with an ileal pouch-anal anastomosis. Sepsis and technical factors are the most common contributors. It is the cause of considerable morbidity. Management depends on the level of the fistula, the amount of pelvic scar tissue, and previous treatments. An algorithm for surgical treatment is suggested.

Long-term follow-up after ileoanal pouch procedure: algorithm for diagnosis, classification, and management of pouchitis

PURPOSE

Inflammation of the ileoanal pouch (pouchitis) is one of the main complications after restorative proctocolectomy, yet its cause remains poorly understood. A standardized definition and diagnostic procedures in pouchitis are lacking.

METHOD

We analyzed all cases of pouchitis occurring in a group of 308 patients (210 with ulcerative colitis, 98 with familial adenomatous polyposis) who took part in a prospective long-term follow-up program. The severity of pouchitis was measured using a pouchitis activity score (Heidelberg Pouchitis Activity Score). An algorithm for the classification and management of pouchitis was established which enables the clinician: 1) to determine the severity of pouchitis, 2) to differentiate between primary pouchitis and pouchitis caused by surgical complications (secondary pouchitis), and 3) to evaluate the course (acute vs. chronic (> 3 months)).

RESULTS

The median duration of follow-up was 48 (range, 13-119) months. At least one episode of pouchitis was diagnosed in 29 percent of patients with ulcerative colitis and in 2 percent of familial adenomatous polyposis patients. Secondary pouchitis occurred in 6 percent of ulcerative colitis patients and was cured by surgical treatment in 13 (87 percent) of 15 cases. Primary pouchitis was diagnosed in 23 percent of ulcerative colitis patients, including 6 percent of all ulcerative colitis patients with chronic primary pouchitis. The latter showed poor response to medical treatment. In one case multifocal high-grade dysplasia occurred. Histologic examination of the excised pouch identified a carcinoma originating from the ileal mucosa.

CONCLUSIONS

Ulcerative colitis patients after restorative proctocolectomy face a high risk of developing pouchitis. The algorithm used in this study was highly efficient in identifying patients with a secondary pouchitis who require surgical treatment and patients with chronic primary pouchitis. For the latter, long-term surveillance seems mandatory because of the risk of malignant transformation of the pouch mucosa.