American gastroenterological associationAGA technical review on perianal Crohn’s disease☆
Section snippets
Strategy for literature identification
A search of the online bibliographic databases MEDLINE (1966 to August 2002) and Current Contents/Science Edition (1996 to August 2002) was performed to identify potentially relevant English-language articles. The Medical Subject Heading terms “Crohn’s disease” or “inflammatory bowel disease” or “regional enteritis” AND “fistulas” or “perianal” were used to perform keyword searches of the database. Manual searches of the reference lists from the potentially relevant papers and the proceedings
Normal anatomy
To understand the etiology and classification of perianal fistulas and other perianal lesions, a review of perianal anatomy is required. The anal canal consists of an inner layer of circular smooth muscle extending downward from the rectum called the internal anal sphincter, the intersphincteric space, and an outer layer of skeletal muscle extending downward from the puborectalis and levator ani muscles called the external anal sphincter (Figure 1). The dentate line, located in the midportion
Epidemiology
In a combined medical and surgical Crohn’s disease follow-up clinic, 110 of 202 consecutive patients (54%) had evidence of past or current perianal complications.12 The types and distribution of perianal lesions are shown in Table 4.
The cumulative frequency of perianal fistulas in patients with Crohn’s disease has been reported to range from 14% to 38% in patients evaluated at referral centers,13, 14, 15, 16, 17, 18 from 17% to 28% in patients undergoing surgery for Crohn’s disease,19, 20, 21
Diagnosis
Modalities used to diagnose and classify Crohn’s perianal fistulas include EUA, fistulography, computed tomography, pelvic MRI, and anorectal EUS.
Measurement of fistula disease activity
The Crohn’s Disease Activity Index score was developed to measure disease activity in patients whose symptoms originate primarily from luminal disease.61 Accordingly, patients whose symptoms originate primarily from perianal fistulas usually have low Crohn’s Disease Activity Index scores.62 Thus, the Crohn’s Disease Activity Index is not suitable for measuring fistula activity.63 Present et al. were the first to attempt measurement of fistula activity using a therapeutic goals score.64 Patients
Medical treatment
The pharmaceutical agents with definite or potential efficacy for treating patients with perianal Crohn’s disease include antibiotics, azathioprine and 6-mercaptopurine, infliximab, cyclosporine, and tacrolimus.
Surgical treatment
Early reports from referral centers have suggested that the clinical course of perianal Crohn’s disease is relatively benign and that a low percentage of patients (approximately 10%–18%) require proctectomy, thus leading to the recommendation of a conservative approach with respect to surgery.144, 145, 146 However, population-based natural history studies and more recent reports have suggested that the rates of recurrent disease and proctectomy are relatively high, suggesting a greater role for
Approach to treatment
The treatment of perianal fistulas in patients with Crohn’s disease should be approached with knowledge of the relevant perianal anatomy, diagnostic modalities, and medical and surgical treatment options. The therapeutic plan devised for each patient must take into account the activity of the proximal luminal Crohn’s disease and, in particular, disease activity in the rectum, the location and type of fistulas present, and the severity of the patient’s symptoms.
Conclusions
Perianal disease occurs frequently in patients with Crohn’s disease. Diagnostic evaluation with physical examination and rectosigmoid endoscopy, supplemented in some cases with EUA and anorectal ultrasonography or pelvic MRI, is required to determine the location and type of fistulas and the presence or absence of macroscopic rectal inflammation. Skin tags and hemorrhoids should not be operated on. Most anal fissures should not be operated on. Lateral sphincterotomy can be considered in
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Surgical Options for the Treatment of Perianal and Anovaginal Fistulas in the Setting of Ileoanal Pouch Crohn’s Disease: Experience of a Tertiary Center
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2023, The Lancet Gastroenterology and Hepatology
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W. J. S. has consulted for Prometheus Laboratories, GlaxoSmithKline, Centocor, Novartis, and Fujisawa. He has received research support from Prometheus Laboratories, Schering-Plough, Centocor, and Fujisawa. He has participated in continuing medical education events indirectly sponsored by Prometheus Laboratories, Schering-Plough, and Centocor. B. G. F. has consulted for Centocor and Novartis. He has received research support from Schering-Plough and Centocor. He has participated in continuing medical education events indirectly sponsored by Schering-Plough and Centocor. S. B. H. has consulted for and received research support from Centocor. He has participated in continuing medical education events indirectly sponsored by Schering-Plough and Centocor.
The Clinical Practice Committee thanks the following individuals whose critiques of this review paper provided valuable guidance to the authors: Jeffrey L. Barnett, M.D., Geert D’Haens, M.D., Ph.D., Francis A. Farraye, M.D., M.Sc., Jeffrey A. Katz, M.D., and Gary R. Lichtenstein, M.D.