Anorectal abscess and fistula

Persistent Fistula After Anorectal Abscess Drainage: Local Experience of 11 Years

BACKGROUND

The characteristics of patients who develop a fistula-in-ano after an anorectal abscess are unclear.

OBJECTIVE

Our study explored this relationship and patient factors associated with fistula development.

DESIGN

International Classification of Diseases, 10 Revision, and Classification of Interventions and Procedures, version 4, codes were used to identify all of the patients with a primary anorectal abscess. Multivariable analysis was used to identify factors predictive of fistula formation.

SETTINGS

The study was conducted in a district general hospital.

PATIENTS

Patients with anorectal abscess who were admitted to our institution (2004-2015) were included.

MAIN OUTCOMES MEASURES

The rate of subsequent fistula formation was measured.

RESULTS

A total of 1970 abscess patients were identified; 70.0% (n = 1379) were men, and 7.3% (n = 144) had Crohn's disease. Fistulas occurred in 16.2% (n = 319) at a median of 7 months (interquartile range, 3-7 mo). Patients with Crohn's disease were more than twice as likely to develop a fistula than patients without Crohn's disease (32.6% vs 14.9%; OR = 2.5 (95% CI, 1.7-3.7); p < 0.001). Patients with Crohn's disease with a fistula were more likely to be women (55.3% vs 34.6%; p = 0.007) and aged <30 years (51.1% vs 24.3%; p< 0.001) versus patients without Crohn's disease with a fistula. At multivariable analysis of the entire cohort, male sex (OR = 0.7 (95% CI, 0.5-0.9); p = 0.005) and diabetes mellitus (OR = 0.5 (95% CI, 0.3-0.9); p = 0.027) were associated with a reduced likelihood of developing a fistula after abscess formation.

LIMITATIONS

The study was limited by its single-center scope, retrospective analysis, and lack of a standardized definition for Crohn's disease.

CONCLUSIONS

Abscesses are more common in men, but progression to fistula is more likely in women. The rate of fistula progression in Crohn's disease is twice that in patients without Crohn's disease. Identification of patients at risk may help delineate those who will benefit from a more conservative surgical approach, enhanced follow-up, or investigation after abscess drainage. See Video Abstract at http://links.lww.com/DCR/A798.

Management of retrorectal supralevator abscess-results of a large cohort

PURPOSE

Proximal intersphincteric fistulas with proximal extension causing supralevatoric, retrorectal abscesses are a rare disease. There is only very limited experience, with small groups, and the limited published literature confirms the complexity of diagnostics and treatment. The aim of this study was to evaluate transrectal internal abscess drainage as planned definitive treatment.

METHODS

We retrospectively studied medical records of all patients with the diagnosis of retrorectal abscesses that underwent transrectal internal abscess drainage in the Department of Colo-proctology of the University Medical Centre Mannheim (2003-2012).

RESULTS

One hundred nine patients were operated on retrorectal abscesses, 70 (64.2%) men and 39 (35.8%) women. Mean age was 45.3 years (18-81). In 96 cases (88.1%), only a transrectal internal abscess drainage was performed as planned definitive treatment. Primary healing occurred in 60 patients (62.5%). A second transrectal internal drainage procedure was necessary in 27 cases (28.1%) to assure complete internal drainage. All secondary procedures led to subsequent healing. A combined surgical treatment due to coexisting fistula tracts to the perianal skin or additional ischioanal abscesses was required in 13 patients (11.9%), and an additional seton placement was performed. Nine patients (9.4%) underwent one or more reoperations due to previously unidentified complex coexisting fistulas. Most of these patients were immunosuppressed due to Crohn's disease. Internal drainage alone was successful in 90.6% with an overall healing rate of 94.5% for the entire population of complex fistulas.

CONCLUSIONS

Transrectal internal abscess drainage is a safe and highly successful procedure for treatment of retrorectal abscess, with very low risk of postoperative fecal incontinence. Inflammatory bowel disease and immunosuppressives have a negative impact on the healing process.

Natural history of anorectal sepsis

Background

Progression from anorectal abscess to fistula is poorly described and it remains unclear which patients develop a fistula following an abscess. The aim was to assess the burden of anorectal abscess and to identify risk factors for subsequent fistula formation.

Methods

The Hospital Episode Statistics database was used to identify all patients presenting with new anorectal abscesses. Cox regression analysis was undertaken to identify factors predictive of fistula formation.

Results

A total of 165 536 patients were identified in the database as having attended a hospital in England with an abscess for the first time between 1997 and 2012. Of these, 158 713 (95·9 per cent) had complete data for all variables and were included in this study, the remaining 6823 (4·1 per cent) with incomplete data were excluded from the study. The overall incidence rate of abscess was 20·2 per 100 000. The rate of subsequent fistula formation following an abscess was 15·5 per cent (23 012 of 148 286) in idiopathic cases and 41·6 per cent (4337 of 10 427 in patients with inflammatory bowel disease (IBD) (26·7 per cent coded concurrently as ulcerative colitis; 47·2 per cent coded as Crohn's disease). Of all patients who developed a fistula, 67·5 per cent did so within the first year. Independent predictors of fistula formation were: IBD, in particular Crohn's disease (hazard ratio (HR) 3·51; P &lt; 0·001), ulcerative colitis (HR 1·82; P &lt; 0·001), female sex (HR 1·18; P &lt; 0·001), age at time of first abscess 41–60 years (HR 1·85 versus less than 20 years; P &lt; 0·001), and intersphincteric (HR 1·53; P &lt; 0·001) or ischiorectal (HR 1·48; P &lt; 0·001) abscess location compared with perianal. Some 2·9 per cent of all patients presenting with a new abscess were subsequently diagnosed with Crohn's disease; the median time to diagnosis was 14 months.

Conclusion

The burden of anorectal sepsis is high, with subsequent fistula formation nearly three times more common in Crohn's disease than idiopathic disease, and female sex is an independent predictor of fistula formation following abscess drainage. Most fistulas form within the first year of presentation with an abscess.

Clinical value of endoluminal ultrasonography in the diagnosis of rectovaginal fistula

Background

Rectovaginal fistula (RVF) refers to a pathological passage between the rectum and vagina, which is a public health challenge. This study was aimed to explore the clinical value of endoluminal biplane ultrasonography in the diagnosis of rectovaginal fistula (RVF).

Methods

Thirty inpatients and outpatients with suspected RVF from January 2006 to June 2013 were included in the study, among whom 28 underwent surgical repair. All 28 patients underwent preoperative endoluminal ultrasonography, and the obtained diagnostic results were compared with the corresponding surgical results.

Results

All of the internal openings located at the anal canal and rectum of the 28 patients and confirmed during surgery were revealed by preoperative endosonography, which showed a positive predictive value of 100 %. Regarding the 30 internal openings located in the vagina during surgery, the positive predictive value of preoperative endosonography was 93 %. The six cases of simple fistulas confirmed during surgery were revealed by endosonography; for the 22 cases of complex fistula confirmed during surgery, the positive predictive value of endosonography was 90 %. Surgery confirmed 14 cases of anal fistula and 14 cases of RVF, whereas preoperative endoluminal ultrasonography suggested 16 cases of anal fistula and 12 cases of RVF, resulting in positive predictive values of 92.3 and 93 %, respectively.

Conclusion

The use of endoluminal biplane ultrasonography in the diagnosis of RVF can accurately determine the internal openings in the rectum or vagina and can relatively accurately identify concomitant branches and abscesses located in the rectovaginal septum. Thus, it is a good imaging tool for examining internal and external anal sphincter injuries and provides useful information for preoperative preparation and postoperative evaluation.

CT of acute perianal abscesses and infected fistulae: a pictorial essay

Computed tomography (CT) is an effective, readily available diagnostic imaging tool for evaluation of the emergency room (ER) patients with the clinical suspicion of perianal abscess and/or infected fistulous tract (anorectal sepsis). These patients usually present with perineal pain, fever, and leukocytosis. The diagnosis can be easy if the fistulous tract or abscess is visible on inspection of the perianal skin. If the tract or abscess is deep, then the clinical diagnosis can be difficult. Also, the presence of complex tracts or supralevator extension of the infection cannot be judged by external examination alone. Magnetic resonance imaging (MRI) is the best imaging test to accurately detect fistulous tracts, especially when they are complex (Omally et al. in AJR 199:W43-W53, 2012). However, in the acute setting in the ER, this imaging modality is not always immediately available. Endorectal ultrasound has also been used to identify perianal abscesses, but this modality requires hands-on expertise and can have difficulty localizing the offending fistulous tract. It may also require the use of a rectal probe, which the patient may not be able to tolerate. Contrast-enhanced CT is a very useful tool to diagnose anorectal sepsis; however, this has not received much attention in the recent literature (Yousem et al. in Radiology 167(2):331-334, 1988) aside from a paper describing CT imaging following fistulography (Liang et al. in Clin Imaging 37(6):1069-1076, 2013). An infected fistula is indicated by a fluid-/air-filled soft tissue tract surrounded by inflammation. A well-defined round to oval-shaped fluid/air collection is indicative of an abscess. The purpose of this article is to demonstrate the usefulness of contrast-enhanced CT in the diagnosis of acute anorectal sepsis in the ER setting. We will discuss the CT appearance of infected fistulous tracts and abscesses and how CT imaging can guide the ER physician in the clinical management of these patients.

Proposal: a score to select patients for fistulotomy

Traditionally the distance between the inner opening and the anal verge is considered when making the decision to lay open an anal fistula or not. In contrast to this, the score presented here includes the distance to the upper border of the puborectalis muscle or to the external sphincter (anteriorly). In addition this score also takes various aspects of bowel function into consideration.

Who is at risk for developing chronic anal fistula or recurrent anal sepsis after initial perianal abscess?

PURPOSE

This study was designed to determine factors that contribute to chronic anal fistula or recurrent sepsis after initial perianal abscess.

METHODS

A retrospective cohort study was conducted in patients with a first-time perianal abscess who were treated at Kaiser Permanente Los Angeles between 1995 and 2007. Univariate and multivariable analyses were performed with the Cox proportional hazards model to determine predictors of risk for recurrent disease.

RESULTS

One hundred and forty-eight patients met inclusion criteria (105 men, 43 women; mean age, 43.6 years). During a mean follow-up of 38 months, the cumulative incidence of chronic anal fistula or recurrent sepsis was 36.5 percent. Univariate and multivariable analyses showed more than two-fold increased risk of recurrence in patients <40 years vs. those >/=40 years (P < 0.01), and univariate analysis showed nondiabetics were 2.69 times as likely to experience recurrence as diabetics (P = 0.04). No significant differences in risk of recurrence were noted for men vs. women (HR = 0.78; P = 0.39), nonsmokers vs. smokers (HR = 1.17; P = 0.58); perioperative antibiotics vs. no antibiotics (HR = 1.51; P = 0.19); or HIV-positive vs. HIV- negative status (HR = 0.72; P = 0.44).

CONCLUSIONS

Age younger than 40 years significantly increased risk of chronic anal fistula or recurrent anal sepsis after a first-time episode of perianal abscess. Patients with diabetes may have a decreased risk compared with nondiabetic patients. Gender, smoking history, perioperative antibiotic treatment, and HIV status were not risk factors for chronic anal fistula or recurrent anal sepsis.

Management of intersphincteric abscesses

OBJECTIVE

Intersphincteric abscesses are relatively rare, and in some cases of upward extensions in the supralevator plane, can be difficult to manage. The aim of this study was to analyse the type of treatment used in these abscesses.

METHODS

Twenty-one intersphincteric abscesses treated by endoanal drainage in our colorectal unit between 1992 and 2004 were reviewed from our database; location and extension of the abscess, type of treatment and recurrence rates and the use of endoanal ultrasound were studied.

RESULTS

Ninety per cent of patients were male; 10 had a previous history of surgery for perianal abscess and suppuration (48%); 16 (76%) had a posterior location and five were anterolateral. Twelve patients had low intersphincteric abscesses and were treated by laying open the abscess and dividing the internal sphincter. Nine were found to have high extensions into the intermuscular planes and were treated by staged procedures: a temporary transanal mushroom catheter was used in seven patients. Endoanal ultrasound was used initially in seven patients (33.3%) and for the evaluation of definitive treatment in 11 (52%).

CONCLUSIONS

Low intersphincteric abscesses should be treated by de-roofing of the abscess and division of the internal sphincter up to a level of the dentate line. High intersphincteric abscesses are relatively frequent and mostly require staged surgery with a temporary mushroom (de Pezzer) catheter. Accurate anatomical ultrasound localization and proper drainage become important to avoid recurrences or extrasphincteric fistulas.

Surgeon-performed ultrasound: endorectal ultrasound

Endorectal (ERUS) and endoanal (EAUS) ultrasound imaging is increasingly being performed by surgeons in the office and outpatient setting for the assessment of both benign and malignant disease. Multiple studies have demonstrated the accuracy of these modalities in identifying pertinent anatomy and anatomic abnormalities. The ultrasound is easily tolerated by most patients, and is easily performed with minimal preparation on the patient's part. The ability of the surgeon to perform and interpret this straight forward diagnostic procedure allows for the simplification of the diagnostic process and a more rapid determination of treatment options for the patient.

Early reoperation for perirectal abscess: a preventable complication

PURPOSE

The aim of this study was to analyze failures in the operative management of perirectal abscesses resulting in early reoperation.

METHODS

This was a retrospective case study of 500 consecutive patients who underwent 627 drainage procedures for a perirectal abscess.

RESULTS

Forty-eight patients (7.6 percent of all drainage procedures) required reoperation within ten days of the original procedure. The main factors leading to reoperation were incomplete drainage (23 patients), missed loculations within a drained abscess (15 patients), missed abscesses (4 patients), and postoperative bleeding (3 patients). Incomplete drainage was more common with simple perirectal abscesses, whereas most overlooked collections were located posteriorly. Horseshoe abscesses were associated with a particularly high rate (50 percent) of operative failures. Neither preexisting perianal pathology nor systemic immunosuppressive disease contributed to early failures.

CONCLUSION

Surgical errors are the leading cause of early failures in the surgical treatment of perianal abscesses. These errors occur in a limited number of typical patterns and can therefore be identified and taught with an aim to decrease their occurrence.