Rectal strictures in Crohn's disease and coexisting perirectal complications

Typical MR features and interpretation of perianal fistulas in patients with Crohn's disease

Perianal fistulas in Crohn's disease (CD) are a poor prognostic phenotype requiring a combination of medical and surgical management. Perianal fistulas in CD are characterized by more complex and multi-branched fistulas, association with skin tags, and frequent presence of proctitis. A comprehensive approach with clinical examination, endoscopic and MR assessment is required, and in particular, MR interpretation provides detailed information on the type of fistula with its internal component and activity, secondary tracts and extension, internal, external openings, associated abscess, and presence of proctitis. Structured reporting of these items would be recommended for further discussion and management planning both at initial diagnosis and for disease monitoring during treatment follow-up. Management strategy would be individualized for each patient, and control of luminal disease activity could be an important determinant in the selection of treatment options. In this review, we provide an overview of the MRI evaluation of perianal fistulas in CD with a proposed structured MR report.

In-hospital management of inflammatory bowel disease

PURPOSE OF REVIEW

The management of hospitalized patients with inflammatory bowel disease (IBD) is complex. Despite considerable therapeutic advancements in outpatient ulcerative colitis and Crohn's disease management, the in-hospital management continues to lag with suboptimal outcomes. The purpose of this review is to provide a brief overview of our approach to managing patients hospitalized with acute severe ulcerative colitis (ASUC) and Crohn's disease-related complications, followed by a summary of emerging evidence for new management approaches.

RECENT FINDINGS

ASUC has seen the emergence of well validated prognostic models for colectomy as well as the development of novel treatment strategies such as accelerated infliximab dosing, Janus kinase inhibitor therapy, and sequential therapy, yet the rate of colectomy for steroid-refractory ASUC has not meaningfully improved. Crohn's disease has seen the development of better diagnostic tools, early Crohn's disease-related complication stratification and identification, as well as better surgical techniques, yet the rates of hospitalization and development of Crohn's disease-related complications remain high.

SUMMARY

Significant progress has been made in the in-hospital IBD management; however, both the management of ASUC and hospitalized Crohn's disease remain a challenge with suboptimal outcomes. Critical knowledge gaps still exist, and dedicated studies in hospitalized patients with IBD are needed to address them.

Placebo response rates in randomized controlled trials for perianal Crohn's disease: A systematic review and meta-analysis

BACKGROUND AND AIMS

Perianal fistulizing disease is a common complication of Crohn's disease (CD), for which new therapies are urgently needed. To assist design of clinical trials for novel therapeutics, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to quantify placebo rates and identify factors influencing them in perianal CD.

METHODS

We searched MEDLINE, EMBASE and CENTRAL from inception to June 2021. Eligible studies were placebo-controlled trials of pharmacological interventions for perianal CD (pCD). Placebo fistula response and remission rates for induction and maintenance trials were extracted and pooled using a random-effects model. Mixed-effects meta-regression was used to evaluate the impact of patient and study-level characteristics on point estimates.

RESULTS

In 17 RCTs (13 induction, 5 maintenance) the pooled placebo fistula response and remission rate for induction trials was 25% (95% CI 17-36%) and 17% (95% CI 11-25%), respectively. For maintenance trials, the pooled placebo fistula response and remission rate was 23% (95% CI 17-32%) and 19% (95% CI 14-25%), respectively. Trials enrolling patients with less disease activity and a higher proportion with ileal predominant disease were associated with significantly higher placebo response rates. Trials originating in Europe (compared to North America), therapies requiring perianal injection and a longer timepoint to measure remission were associated with higher placebo remission rates.

CONCLUSIONS

Placebo response and remission rates in pCD trials are influenced by patient and disease-related factors, as well as the type of intervention being studied. These contemporary rates will inform trial design for novel therapeutics.

Diagnosis and Classification of Fistula from Inflammatory Bowel Disease and Inflammatory Bowel Disease-Related Surgery

Fistula in inflammatory bowel disease (IBD) is a well-known yet poorly understood phenotype. Pathophysiology is largely based on the activation of the epithelial-mesenchymal transition (EMT); however, interactions with the microbiome, genetics, mechanical stress and the presence of stricturing disease, and surgical complications play a role. Perianal penetrating disease represents a more severe phenotype in IBD. Pouch-associated fistula can arise as a result of an anastomotic leak, surgical complications, or Crohn's disease (CD) of the pouch. Classification is site-dependent, includes a range of severity, and informs management. It is important to determine associated symptoms and recognize the complex interplay of underlying etiologies to form the basis of appropriate care.

Management of Perineal Wounds Following Pelvic Surgery

Despite advancements in understanding and technique, there remain significant challenges in the management of a complex perineal wound following pelvic surgery. Complications including wound sepsis, fistulation, persistent sinus, and herniation produce additional morbidity and health care costs. This article details the methods of optimizing patient and operative factors to mitigate this risk, alongside strategies to deal with sequelae of wound failure.

Time to Revisit Disease Classification in Inflammatory Bowel Disease: Is the Current Classification of Inflammatory Bowel Disease Good Enough for Optimal Clinical Management?

Inflammatory bowel disease (IBD), historically subdivided into Crohn's disease and ulcerative colitis, is a very heterogeneous condition. While the tendency in medicine is to try to reduce complexity, IBD is a disease that cannot justify a one-size-fits-all principle. Our current clinical classification tools are suboptimal and need further refinement to capture, at least in part, the variety of phenotypes encountered in daily clinical practice. Although these revised classification tools alone will not be sufficient and should be complemented by more detailed molecular subclassifications, optimized clinical phenotypes can contribute to improved trial designs, future translational research approaches, and better treatment outcomes. In the current review, we discuss key clinical features important in IBD disease heterogeneity, tackle limitations of the current classification systems, propose some potential improvements, and raise priorities for future research in this domain.

A Multi-Disciplinary Approach to Perianal Fistulizing Crohn's Disease

Perianal fistulizing Crohn's disease represents a severe phenotype associated with significant morbidity. Patients with perianal fistulizing disease are more likely to have a severe disease course and have significant reductions in quality of life. Moreover, these patients are at risk for the development of distal rectal and anal cancers. Given the complexity and severity of this patient group, the management of perianal Crohn's disease must be undertaken by a multidisciplinary team. The gastroenterologist and colorectal surgeon play a critical role in the diagnosis and management of perianal fistulizing disease. An examination under anesthesia provides critical information and is an essential part of the work-up of complex perianal fistulas. The radiologist also plays a central role in characterizing anatomy and assessing response to treatment. Several imaging modalities are available for these patients with magnetic resonance imaging as the imaging modality of choice. Perianal disease developing after ileal pouch-anal anastomosis represents a particularly challenging form of fistulizing disease and requires a multidisciplinary clinical and radiologic approach to differentiate surgical complications from recurrent Crohn's disease.

Modern Management of Perianal Crohn's Disease: A Review

Perianal Crohn's disease (CD) is a complex manifestation of CD that affects approximately 10% of patients. The spectrum of disease is quite variable, ranging from relatively mild disease to severe, aggressive manifestations that result in frequent hospitalizations, multiple surgeries, and poor quality of life. Despite significant recent advances in surgical and medical management, treatment remains challenging and frequently requires a multidisciplinary medical-surgical approach. The goal of this article is to review the current literature regarding the work-up, treatment, and future directions of therapy. Crucial features of effective management include the precise identification of manifestations, control of sepsis, limiting rectal inflammation, frequently with use of antitumor necrosis factor agents, and avoidance of extensive surgery.

Darvadstrocel for the treatment of perianal fistulas in Crohn's disease

INTRODUCTION

Perianal fistulizing Crohn's disease is associated with a poor quality of life and current medical and surgical treatment options are limited. Darvadstrocel, composed of mesenchymal stem (stromal) cells (MSC), has recently been approved by the European Medicines Agency (EMA) for the treatment for perianal disease. This drug profile educates the reader with this novel treatment approach.

AREAS COVERED

A literature search was performed on PubMed with focus on perianal fistulizing Crohn's disease and mesenchymal stem (stromal) cells. This review summarizes evidence of the current standard of care and discusses the mechanism of action, manufacturing, and application and safety of darvadstrocel.

EXPERT OPINION

Darvadstrocel is a safe and effective therapy for complex perianal fistulizing Crohn's disease.

Mesenchymal Stem Cells for Perianal Crohn's Disease

Perianal fistulizing Crohn’s disease (PFCD) is associated with significant morbidity and might negatively impact the quality of life of CD patients. In the last two decades, the management of PFCD has evolved in terms of the multidisciplinary approach involving gastroenterologists and colorectal surgeons. However, the highest fistula healing rates, even combining surgical and anti-TNF agents, reaches 50% of treated patients. More recently, the administration of mesenchymal stem cells (MSCs) have shown notable promising results in the treatment of PFCD. The aim of this review is to describe the rationale and the possible mechanism of action of MSC application for PFCD and the most recent results of randomized clinical trials. Furthermore, the unmet needs of the current administration process and the expected next steps to improve the outcomes will be addressed.

Utility of 360° Real-time Endoanal Sonography for Evaluation of Perianal Fistulas

OBJECTIVES

To assess the diagnostic accuracy and performance of 360° endoanal sonography for preoperative evaluation of perianal fistulas using surgical results as a reference standard.

METHODS

Between January 2012 and May 2016, 122 patients with suspicious anal fistulas and perianal abnormalities had real-time endoanal sonographic examinations using a 360° cross-sectional endoanal transducer (5-13 MHz) for preoperative evaluation of the disease. All patients underwent surgical interventions. The sonographic findings, including the fistulas and other inflammatory lesions, were correlated with surgical results. The types of fistulas on endoanal sonography were compared with the surgical classification of Parks et al (Br J Surg 1976; 63:1-2), and the internal opening of the fistula on endoanal sonography was confirmed by surgical results as a reference standard.

RESULTS

The 122 patients studied included 111 male and 11 female patients. Endoanal sonography was able to show and track hypoechoic lesions, their locations, and internal openings of the fistulas. Compared with surgical results, endoanal sonography had sensitivity of 92.2%, specificity of 100%, and accuracy of 93.4% for the diagnosis of perianal fistulas. Also, endoanal sonography had accuracy of 87.4% for determining fistula types based on the Parks classification and 94.6% for identifying internal openings of the fistulas.

CONCLUSIONS

Endoanal sonography is an accurate and noninvasive imaging modality for evaluation of fistulas. It is a very useful tool for preoperative management and surgical planning by providing precise and detailed information on fistulas.

Perianal fistulizing Crohn's disease: pathogenesis, diagnosis and therapy

Perianal fistulizing Crohn's disease has a major negative effect on patient quality of life and is a predictor of poor long-term outcomes. Factors involved in the pathogenesis of perianal fistulizing Crohn's disease include an increased production of transforming growth factor β, TNF and IL-13 in the inflammatory infiltrate that induce epithelial-to-mesenchymal transition and upregulation of matrix metalloproteinases, leading to tissue remodelling and fistula formation. Care of patients with perianal Crohn's disease requires a multidisciplinary approach. A complete assessment of fistula characteristics is the basis for optimal management and must include the clinical evaluation of fistula openings, endoscopic assessment of the presence of proctitis, and MRI to determine the anatomy of fistula tracts and presence of abscesses. Local injection of mesenchymal stem cells can induce remission in patients not responding to medical therapies, or to avoid the exposure to systemic immunosuppression in patients naive to biologics in the absence of active luminal disease. Surgery is still required in a high proportion of patients and should not be delayed when criteria for drug failure is met. In this Review, we provide an up-to-date overview on the pathogenesis and diagnosis of fistulizing Crohn's disease, as well as therapeutic strategies.

Anorectal stricture in 102 patients with Crohn's disease: natural history in the era of biologics

BACKGROUND

The natural history of nonfistulising perianal Crohn's disease (PCD) remains unknown.

AIM

To assess the long-term outcome of anorectal strictures.

METHODS

All outcomes of PCD patients with anorectal stricture followed in a single unit from 2005 to 2013 were reviewed, as well as subsequent therapeutic management. Cumulative incidence of stricture healing (disappearance of the anal stricture) was estimated using a Kaplan-Meier method and factor associated with an unfavourable course (persistent stricture S2, persistent stoma or proctectomy) with nonparametric test.

RESULTS

A total of 102 patients (M/F: 37/65) were included. The duration of CD at diagnosis was 8.9 years. After a median follow-up period of 2.8 years, 52 of the 88 followed patients (59%) achieved anorectal stricture healing. Two patients (2%) developed anal adenocarcinoma. Female gender [HR 2.05 (1.1-4.03), P = 0.0221], disease duration of CD of less than 10 years [HR 1.94 (1.01-3.63), P = 0.0271], and anal fistula at stricture diagnosis [HR 2.36 (1.21-5.05), P = 0.0106) were significantly associated with anorectal stricture healing in a multivariate analysis model. Twenty-eight patients (32%) had an unfavourable course at the end of follow-up. Gender and introduction or optimisation of TNFα antagonist treatment decreased the risk of unfavourable course in multivariate analysis. Conversely, the Luminal B2 phenotype at CD diagnosis was the only factor associated with unfavourable course.

CONCLUSIONS

Anorectal stricture does not imply a nonreversible and complicated condition related to severe perianal Crohn's disease. However, both the diagnosis of cancer and sepsis drainage remain challenging in this situation.

Usefulness of 3D transperineal ultrasound in severe stenosis of the anal canal: preliminary experience in four cases

Background

Organic or functional anal canal stenoses are uncommon conditions that occur in the majority of cases as a consequence of anal diseases. A proper assessment is fundamental for decision making; however, proctological examination and endoanal ultrasound are often unfeasible or very difficult to perform even under local or general anesthesia. We therefore began to use 3D transperineal ultrasound to assess patients. The aim of this study was to compare the results of evacuation proctography and 3D transperineal ultrasound in patients with severe anal canal stenosis.

Methods

Four consecutive patients with high-grade anal canal stenosis were evaluated using both proctography and 3D transperineal ultrasound with a micro-convex transducer between March and June 2011.

Results

In all cases, 3D transperineal ultrasound provided detailed information on the length and level of stenosis and on the integrity of the anal sphincters.

Conclusions

Our preliminary experience suggests that 3D transperineal ultrasound makes it possible to plan optimal surgical treatment.

Diagnosis and treatment of perianal Crohn disease: NASPGHAN clinical report and consensus statement

Inflammatory bowel disease is a chronic inflammatory disorder of the gastrointestinal tract that includes both Crohn disease (CD) and ulcerative colitis. Abdominal pain, rectal bleeding, diarrhea, and weight loss characterize both CD and ulcerative colitis. The incidence of IBD in the United States is 70 to 150 cases per 100,000 individuals and, as with other autoimmune diseases, is on the rise. CD can affect any part of the gastrointestinal tract from the mouth to the anus and frequently will include perianal disease. The first description connecting regional enteritis with perianal disease was by Bissell et al in 1934, and since that time perianal disease has become a recognized entity and an important consideration in the diagnosis and treatment of CD. Perianal Crohn disease (PCD) is defined as inflammation at or near the anus, including tags, fissures, fistulae, abscesses, or stenosis. The symptoms of PCD include pain, itching, bleeding, purulent discharge, and incontinence of stool. In this report, we review and discuss the etiology, diagnosis, evaluation, and treatment of PCD.

Transperineal ultrasonography in perianal Crohn's disease and recurrent cryptogenic fistula-in-ano

AIM

Successful anal fistula care is aided by specialized imaging accurately defining the site of the internal opening and fistula type. Imaging techniques are complementary, designed to answer specific anatomical questions. There are limited data concerning the clinical value of transperineal ultrasound (TP-US) in both cryptogenic fistula-in-ano and perianal Crohn's disease (PACD). The aim of the study was to assess the accuracy of TP-US compared with operative findings in patients with perirectal sepsis.

METHOD

Patients with recurrent cryptogenic anal fistula and PACD referred for sonography were examined using TP-US by a single examiner blinded to the operative results. Fistulae were categorized by the Parks classification predicting the site of the internal fistula opening. Ancillary horseshoe collections, abscesses and secondary tracks were defined.

RESULTS

Fourteen patients with PACD and 27 patients with recurrent cryptogenic fistula-in-ano were analysed with comparative images and operative data. Correlation of fistula type for cryptogenic and PACD patients respectively was 23/27 (85.2%) and 12/14 (85.7%), with a correlative internal opening site (when found at surgery) of 16/22 (72.3%) and 12/14 (85.7%). Misclassification of fistula type in cryptogenic cases occurred in the presence of ancillary abscesses with associated acoustic shadowing. In PACD patients, TP-US was used when anal stenosis precluded endoanal ultrasonography, assisting in the diagnosis of recto-vaginal fistulae.

CONCLUSION

TP-US is a useful complementary technique to assess fistula-in-ano and has special advantage when there is anal canal distortion, complex fistula type or suspicion of a recto-vaginal fistula.

Prevention and management of nonhealing perineal wounds

Complex perineal wounds are at risk for nonhealing. High-risk procedures include proctectomy for Crohn disease, anal cancer and radiated distal rectal cancers. A basic understanding of both patient and procedural risk factors is helpful in planning and executing operative procedures for these conditions and to minimize associated wound complications. Diabetes, obesity, and malnutrition may contribute to wound breakdown and failure to heal. Delaying operative intervention, adding nutritional supplementation, and employing intestinal diversion as well as myocutaneous flaps may help optimize conditions for wound healing.

Transperineal ultrasonography as a complementary diagnostic tool in identifying acute perianal sepsis

BACKGROUND

Successful anal fistula care in complex cases can be assisted by specialized imaging which accurately defines the site of the internal fistula opening and the fistula type. There are currently limited data concerning the clinical indications for and accuracy of transperineal ultrasound (TP-US) in acute perianal sepsis. The aims of this study were to compare the anatomical interpretation of TP-US images with magnetic resonance imaging (MRI) and surgical findings in an unselected patient cohort presenting with acute perianal sepsis.

METHODS

Sixty-seven consecutive patients with acute anorectal sepsis referred from the surgical department were examined using TP-US and Gadolinium-enhanced MRI with both examiners blinded to the surgical results. Fistulae were categorized by the Parks' classification of fistula type.

RESULTS

Thirty-six abscesses were detected by MRI, 38 by TP-US and 30 by surgical examination. Operatively discordant cases showed only ischiorectal panniculitis. TP-US was more accurate in the diagnosis of superficial sepsis and MRI in the diagnosis of deep-seated perirectal infection. TP-US and MRI show concordance with operative findings in fistula diagnosis with a tendency for TP-US to overdiagnose trans-sphincteric fistulae and MRI to over diagnose extra-sphincteric fistulae. Comparison of TP-US with MRI showed good agreement for perianal abscess diagnosis (τ = 0.82) and for fistula diagnosis (τ = 0.68). For fistulae, TP-US showed moderate agreement with surgery (τ = 0.43) with only fair agreement between MRI and surgery (τ = 0.29).

CONCLUSIONS

Transperineal ultrasound complements other imaging modalities in the anatomical diagnosis of acute perianal abscesses and fistulae. It has specific advantages over other techniques and is accurate in the detection of superficially located perirectal sepsis showing concordance with MRI and surgical findings.

The transanal approach with laparoscopy or laparotomy for the treatment of rectal strictures in Crohn's disease

INTRODUCTION

Rectal strictures in patients with Crohn's colitis are common and options described for their treatment include direct steroid injection, injection of tumor necrosis factor (TNF) inhibitors, endoscopic balloon dilatation, use of Hegar dilators, stricturoplasty, and proctectomy. Adequate treatment is a challenge, especially with respect to the prevention of stricture recurrence. We present an option for the surgical treatment of these strictures using a transanal resection of the rectum with the addition of laparoscopy or laparotomy.

METHODS

Three patients who had medically refractory or chronic Crohn's colitis with rectal strictures were referred to us after failed medical management, rectal dilation, and balloon dilation of the strictures. In each case, we performed a transanal sphincter preserving dissection in the prone position and used the lithotomy position for intraabdominal mobilization, completion of the rectosigmoid resection, pull-through of the left colon, and coloanal anastomosis.

RESULTS

We resected the rectal strictures transanally in all three cases. One case provided the opportunity to perform a laparoscopy-assisted procedure, whereas the other 2 patients had laparotomy-assisted rectosigmoid resections. We did a coloanal anastomosis in 2 patients with healthy left colon. In the third case, the anal canal was preserved, but the patient was left with a stoma.

CONCLUSIONS

Transanal resection is feasible in the surgical treatment of rectal strictures in patients with Crohn's colitis. It preserves the anal sphincteric mechanism and may help in avoiding a permanent stoma in a subgroup of patients. We found the prone position very helpful in performing the transanal rectal dissection.

Acute hip pain and inability to ambulate: a rare presentation for perirectal abscess

A patient with acute hip pain out of proportion to physical findings and inability to weight bear despite negative plain films warrants further in-depth evaluation. Correctly diagnosing the cause of hip pain, a common emergency department (ED) complaint, may be a challenge in the geriatric population (Perron A, Miller M, Brady W. Orthopedic pitfalls in the ED: radiographically occult hip fracture. Am J Emerg Med 2002; 20: 234-7; Cannon J, Silvestri S, Munro M. Imaging choices in occult hip fracture. J Emerg Med 2009; 37: 144-52; Kiu A, Khan S. Radiology of acute hip and femoral injuries. Br J Hosp Med (London) 2010; 71: M22-M24; Zacher J, Gursche A. Regional musculoskeletal conditions: hip pain. Best Pract Res Clin Rheumatol 2003; 17: 71-85). A perirectal abscess as a cause of acute hip pain and inability to ambulate, with gluteus muscle inflammation but no evidence for bone or joint infection, has not been described, to the authors' knowledge. An 82-year-old woman with a history of diabetes, previously ambulatory, presented to the ED after being found on her apartment floor by a visiting health aide, complaining of acute pain in her left hip. Pain was exacerbated by palpation and range of motion testing, and she was unable to bear weight. There was no report of fever, rectal or abdominal pain, bleeding, or painful defecation. Plain films were negative for fracture or lytic lesion. Computerized tomography (CT) of the hip and pelvis was then obtained, which was negative for boney abnormality but revealed a 5-cm ischiorectal abscess with inflammation of the adjacent gluteus muscle. This case illustrates the potentially subtle nature of a deep perirectal abscess in an elderly patient. The CT imaging, useful for investigating the possibility of occult femoral neck fracture, was fortuitous in leading to the diagnosis. One must consider the possibility of visceral processes causing referred pain, when evaluating the patient with an acutely painful hip (Perron A, Miller M, Brady W. Orthopedic pitfalls in the ED: radiographically occult hip fracture. Am J Emerg Med 2002; 20: 234-7; Zacher J, Gursche A. Regional musculoskeletal conditions: hip pain. Best Pract Res Clin Rheumatol 2003; 17: 71-85).

An innovative sphincter preserving pull-through technique with en bloc colon and small bowel transplantation

This report describes a new innovative pull-through technique of hindgut reconstruction with en bloc small bowel and colon transplantation in a Crohn's disease patient with irreversible intestinal failure. The approach was intersphincteric and the anastomosis was established between the allograft colon and the recipient anal verge with achievement of full nutritional autonomy and anal continence.

Nonfistulizing perianal Crohn's disease: clinical features, epidemiology, and treatment

Nonfistulizing perianal lesions, including ulcerations, strictures, and anal carcinoma, are frequently observed in Crohn's disease. Their clinical course remains poorly known. The management of these lesions is difficult because none of the treatments used is evidence-based. Ulcerations may be symptomatic in up to 85% of patients. Most ulcerations heal spontaneously but may also progress to anal stenosis or fistula/abscess. Topical treatments only improve symptoms, while complete healing can occur in patients with perianal ulcerations receiving infliximab therapy. Half of all patients with anal strictures will require permanent fecal diversion. Dilatation for symptomatic strictures should be performed on a highly selective basis in the absence of active rectal disease in order to avoid infectious complications. Anorectal strictures associated with rectal lesions should first be managed with medical therapy. Skin tags are usually painless and may hide other perianal lesions. Anal cancer is uncommon. Its treatment is similar to that recommended for anal cancer occurring in non-Crohn's disease patients. After reviewing the classification, clinical features, and epidemiology of each type of nonfistulizing perianal lesion (ulceration, stricture, skin tags, and anal cancer), we discuss the efficacy of medical treatment and surgery. This review article may help physicians in decision-making when managing potentially disabling lesions.

Imaging of perianal fistulas

Perianal fistulas, cryptoglandular or Crohn's disease-related, have a tendency to recur. Recurrence usually is owing to missed infection during surgery for cryptoglandular fistulas or insufficient response to medical treatment in Crohn's disease. It is now recognized that preoperative imaging (endoanal ultrasound and magnetic resonance imaging) can help to identify extensions that otherwise would be missed during surgery and therefore prevent recurrence. For medical therapy, the extent of the disease and the presence of abscesses are identified with imaging and therapy response can be monitored. The purpose of this review is to give an up-to-date overview of the anal anatomy, classification of perianal fistulas, and the role of imaging modalities in the management of patients with perianal fistulas.

Anal skin tags in inflammatory bowel disease: new observations and a clinical review

BACKGROUND

The association between intestinal Crohn's disease (CD) and specific perianal abnormalities called anal skin tags (AST) has been recognized but not well defined. Skin tags have been classified into 2 types: 1) raised, broad, or narrow, single or multiple, soft or firm, and painless, often referred to as "elephant ears"; or 2) edematous, hard, often cyanotic, tender or not, and typically arising from a healed anal fissure, ulcer, or hemorrhoid. The aims of this study were to i) better characterize those skin tags identified by the term "elephant ears" and differentiate them from other types of AST; ii) compare their prevalence in patients with CD and ulcerative colitis (UC); iii) observe the relationship of the skin tags to the location of the primary bowel disease; and iv) to discuss the value of these typical AST in making an early diagnosis of CD.

METHODS

Photographs of all AST were taken when present at lower endoscopy in 170 consecutive patients with inflammatory bowel disease (IBD) seen in the private office of the senior investigator and Lenox Hill Hospital. Data was gathered with respect to major differences between the 2 types of AST. The location of the primary bowel disease for these patients was obtained from an extensive IBD computer database and review of details from charts.

RESULTS

Specific features of AST were described and served to favor type 1 versus type 2. AST were found more frequently in patients with CD (75.4%) as compared to patients with UC (24.6%), confirming previous observations that they are more diagnostic of CD (P = 0.005). Subset analysis revealed a trend with a greater incidence of AST in patients with colitis (46.9%) as compared to patients with ileitis (36.7%) and ileocolitis (16.3%) (P = 0.067).

CONCLUSIONS

We provide photographs with the most characteristic features of AST and attempt to separate elephant ears (type 1) from less typical AST (type 2) in CD. Our study confirms previous reports that AST are more commonly found in association with CD as compared with UC and more so in the presence of disease limited to the colon as compared to disease elsewhere in the bowel. Our observations support the diagnostic significance of AST heralding the diagnosis of CD when they are discovered on physical exam, especially in young people with diarrhea, abdominal pain, and/or growth retardation.