Randomized controlled trial of primary fistulotomy with drainage alone for perianal abscesses

Proposal for a new classification of anorectal abscesses based on clinical characteristics and postoperative recurrence

BACKGROUND

Current surgical procedures for anorectal abscesses, including incision and drainage alone or combined concurrent fistulotomy, remain controversial primarily due to the unpredictability of postoperative recurrence or the progression to anal fistula.

AIM

To evaluate factors that predict postoperative recurrence of anorectal abscesses and propose a new classification to guide surgical procedures.

METHODS

In this retrospective study, 525 patients with anorectal abscesses treated by incision and drainage alone, at a tertiary general hospital from August 2012 to July 2022, were included. A new classification for anorectal abscesses based on their propensity to develop into fistulas, considering 18 other potential risk factors, was established. These factors, from electronic medical records, were screened for significance using the χ² test and subsequently analyzed with multivariate logistic regression to evaluate their relationship with postoperative recurrence of anorectal abscesses.

RESULTS

One year post-follow-up, the overall recurrence rate was 39%:81.0% and 23.5% for fistula-prone and non-fistula-prone abscesses, respectively. Univariate χ² analysis showed significant differences in recurrence rates based on anatomical classifications and pus culture results (P < 0.05). Fistula-prone abscess, ≥ 7 days between symptom onset and surgery, chronic diarrhea, preoperative antibiotic use, and local anesthesia were risk factors for recurrence, while diabetes mellitus was protective (P < 0.05). Moreover, fistula-prone abscess [odds ratio (OR) = 7.651, 95%CI: 4.049–14.458, P < 0.001], ≥ 7 days from symptom onset to surgery (OR = 2.137, 95%CI: 1.090–4.190, P = 0.027), chronic diarrhea (OR = 2.508, 95%CI: 1.216–5.173, P = 0.013), and local anesthesia (OR = 2.308, 95%CI: 1.313–4.059, P = 0.004) were independent risk factors for postoperative anorectal abscess recurrence using multivariate logistic regression. Body mass index ≥ 28 (OR = 2.935, 95%CI: 1.203–7.165, P = 0.018) was an independent risk factor for postoperative recurrence of non-fistula-prone abscess.

CONCLUSION

The choice of surgical procedure for treating anorectal abscesses should follow this new classification. Prompt and thorough incision and drainage can significantly reduce postoperative recurrence.

Anorectal Abscess

Anorectal abscesses are a common colorectal emergency. The hallmark of treatment is obtaining source control while avoiding injury to the underlying sphincter complex. Understanding the anatomy of an anorectal abscess is critical to planning the appropriate drainage strategy and decreasing the risk of complex fistula formation. Use of antibiotics should be reserved for those with extensive cellulitis, signs of systemic infection, or patients who are immunocompromised. Whether antibiotics prevent future fistula formation is an area of active research. Primary fistulotomy at time of the index drainage is controversial; however, there may be situations where it is appropriate. It is important to counsel patients that after effective drainage of an anorectal abscess, they have a 30 to 50% chance of developing an anal fistula that will then require further treatment.

Recurrence and incidence of fistula after urgent drainage of an anal abscess. Long-term results

INTRODUCTION

Anal abscess is the most frequent urgent proctological problem. The recurrence rate and reported incidence of fistula after drainage and debridement of an anal abscess is widely variable. The objective of this study is to analyse the long-term recurrence rate and the incidence of fistula after drainage and urgent debridement of an anal abscess.

METHODS

Retrospective observational study of a prospective cohort with anal abscess of cryptoglandular origin. All patients (n = 303) were evaluated two months and one year after the intervention. At the 5^th year, all the medical records were reviewed and a telephone call or appointment was made for an assessment if necessary. Specific antecedents of anal pathology, abscess characteristics, time and type of recurrence, presence of symptoms in the first revision and presence of clinical and/or ultrasound fistula were recorded.

RESULTS

Mean follow-up 119.7 months. Recurrence rate 48.2% (82.2% in the first year). Two hundred twenty-two ultrasounds performed. Incidence of ultrasound fistula: 70% symptomatic vs. 2.4% asymptomatic (p < 0.001). Global incidence of fistula 40.3%. The history of anal pathology and the presence of symptoms in the postoperative review significantly increase the possibility of recurrence (p < 0.001). The fistula is statistically more frequent if the abscess recurs (p < 0.001).

CONCLUSION

After drainage and debridement of an anal abscess, half of the patients relapse and 40% develop fistula especially in the first year, so longer follow-ups are not necessary. Endoanal ultrasound for the evaluation of the presence of fistula is highly questionable in the absence of signs or symptoms.

Efficacy of Permacol injection for perianal fistulas in a tertiary referral population: poor outcome in patients with complex fistulas

AIM

Injection of Permacol collagen paste can be used as a sphincter-sparing treatment for perianal fistulas. In a tertiary referral population we aimed to evaluate the efficacy of Permacol injection and the clinical and fistula-related factors associated with recurrence.

METHOD

This was a retrospective analysis of consecutive patients with perianal fistulas treated with Permacol injection at a specialist centre between June 2015 and April 2019. Endoanal ultrasonography was systematically reanalysed, blinded to treatment outcome. Rectovaginal, anovaginal and Crohn's disease fistulas were excluded. Healed fistulas were defined as absent anal symptoms and a closed external opening on physical examination at a minimum follow-up of 6 months. Regression analyses were performed to identify factors associated with unhealed fistulas.

RESULTS

A total of 90 patients (51 men; median age 45 years) were analysed. Seventy-two (80.0%) patients had complex perianal fistulas (greater than one-third sphincter involvement or multiple tracts). After a single Permacol injection, fistulas were healed in 20 (22.2%) patients at 3 months follow-up and in 18 (20.0%) patients at a median follow-up of 30 months (interquartile range 17-37). Eight (11.1%) patients with unhealed fistulas had significant improvement in their symptoms. Complex fistulas were significantly associated with unhealed status [OR 3.53 (95% CI 1.12-11.09); p = 0.031]. Twenty patients underwent subsequent Permacol injections, which were successful in six (30.0%) patients after one (n = 3) or two (n = 3) additional injections.

CONCLUSION

This largest study to date in patients with mainly complex perianal fistulas, demonstrated that the efficacy of a single Permacol injection was only 20%. Complex fistulas were associated with a poor outcome.

Intersphincteric Exploration With Ligation of Intersphincteric Fistula Tract or Attempted Closure of Internal Opening for Acute Anorectal Abscesses

BACKGROUND

Acute anorectal abscesses of cryptoglandular origin are commonly managed by incision and drainage, which results in fistula development in up to 73% of cases, requiring subsequent definitive fistula surgery. However, given that fistula tracts may already be present at the initial presentation, primary closure of the tract as secondary prevention of fistula formation, using ligation of intersphincteric fistula tract, may be useful.

OBJECTIVE

This study aims to examine the feasibility and outcomes of performing intersphincteric exploration with ligation of intersphincteric fistula tract or attempted closure of internal opening for acute anorectal abscesses.

DESIGN

This is a retrospective study of patients with acute anorectal cryptoglandular abscesses who underwent surgery between January 2014 and December 2016.

SETTINGS

The patients were treated at a tertiary referral center in Thailand.

PATIENTS

Eighty-six patients with acute anorectal abscesses without previous surgery were included.

INTERVENTIONS

Intersphincteric dissection was performed. Further surgical intervention was dependent on the intersphincteric findings.

MAIN OUTCOME MEASURE

The main outcome measure was the 90-day healed rate.

RESULTS

Of the 86 patients, 3 had low intersphincteric abscesses, 26 had low transsphincteric abscesses, 25 had anterior high transsphincteric abscesses, 27 had posterior high transsphincteric abscesses, and 5 had high intersphincteric abscesses. Ligation of intersphincteric fistula tract was successfully performed in 66 patients with an identifiable intersphincteric tract. Intersphincteric exploration with attempted closure of the internal opening was performed in the remaining 20 patients. The success rates were 86% and 70%. Unidentified internal opening and intersphincteric pathology were risk factors for nonhealing. No patients reported fecal incontinence postoperatively.

LIMITATIONS

The limitation of this study is its retrospective nature and that all operations were performed by a single surgeon; therefore, the results may vary according to the individual surgeon's expertise.

CONCLUSIONS

Fistula tract formation was found in most cases of acute anorectal abscesses. Definitive surgery using this strategy provides promising results. See Video Abstract at http://links.lww.com/DCR/B451.

EXPLORACIN INTERESFINTRICA CON LIGADURA DEL TRAYECTO EN LA FSTULA INTERESFINTRICA O INTENTO DE CIERRE DEL ORIFICIO INTERNO EN ABSCESOS ANORRECTALES AGUDOS

ANTECEDENTES:Los abscesos anorrectales agudos de origen criptoglandular, comúnmente se manejan mediante incisión y drenaje, lo que resulta en el desarrollo de una fístula hasta en un 73% de los casos, requiriendo posteriormente cirugía definitiva de la fístula. Sin embargo, dado que los trayectos de la fístula ya pueden estar inicialmente presentes, puede ser útil el cierre primario del trayecto, como prevención secundaria en la formación de la fístula, mediante la ligadura del trayecto de la fístula interesfintérica.OBJETIVO:El estudio tiene como objetivo, examinar la viabilidad y los resultados en realizar exploración interesfintérica, con ligadura del trayecto de fístula interesfintérica o intento de cierre del orificio interno para abscesos anorrectales agudos.DISEÑO:Se trata de un estudio retrospectivo de pacientes con abscesos criptoglandulares anorrectales agudos, que fueron operados entre enero de 2014 y diciembre de 2016.AJUSTES:Los pacientes fueron tratados en un centro de referencia terciario en Tailandia.PACIENTES:Se incluyeron 86 pacientes con abscesos anorrectales agudos, sin cirugía previa.INTERVENCIONES:Se realizó disección interesfintérica. La intervención quirúrgica adicional dependió de los hallazgos interesfintéricos.PRINCIPALES MEDIDAS DE RESULTADO:La principal medida de resultado, fue la tasa de cicatrización a 90 días.RESULTADOS:De los 86 pacientes, hubo 3 abscesos interesfintéricos bajos, 26 abscesos transesfintéricos bajos, 25 abscesos transesfintéricos anteriores altos, 27 abscesos transesfintéricos posteriores altos y 5 abscesos interesfintéricos altos. La ligadura del tracto de la fístula interesfintérica, con tracto interesfintérico identificable, se realizó con éxito en 66 pacientes. Se realizó exploración interesfintérica, con intento de cierre del orificio interno en los 20 pacientes restantes. Las tasas de éxito fueron 86% y 70% respectivamente. Orificio interno no identificado y patología interesfintérica, fueron factores de riesgo para la falta de cicatrización. Ningún paciente reportó incontinencia fecal posoperatoria.LIMITACIONES:La limitación de este estudio, es su naturaleza retrospectiva y que todas las operaciones fueron realizadas por un solo cirujano, por lo tanto, los resultados pueden variar según la experiencia de cada cirujano.CONCLUSIONES:En la mayoría de los casos de abscesos anorrectales agudos, se encontró formación de trayectos fistulosos. La cirugía definitiva con esta estrategia, proporciona resultados prometedores. Consulte Video Resumen en http://links.lww.com/DCR/B451.

Recurrence and incidence of fistula after urgent drainage of an anal abscess. Long-term results

INTRODUCTION

Anal abscess is the most frequent urgent proctological problem. The recurrence rate and reported incidence of fistula after drainage and debridement of an anal abscess is widely variable. The objective of this study is to analyse the long-term recurrence rate and the incidence of fistula after drainage and urgent debridement of an anal abscess.

METHODS

Retrospective observational study of a prospective cohort with anal abscess of cryptoglandular origin. All patients (n = 303) were evaluated two months and one year after the intervention. At the 5th year, all the medical records were reviewed and a telephone call or appointment was made for an assessment if necessary. Specific antecedents of anal pathology, abscess characteristics, time and type of recurrence, presence of symptoms in the first revision and presence of clinical and/or ultrasound fistula were recorded.

RESULTS

Mean follow-up 119.7 months. Recurrence rate 48.2% (82.2% in the first year). Two hundred twenty-two ultrasounds performed. Incidence of ultrasound fistula: 70% symptomatic vs. 2.4% asymptomatic (p < 0.001). Global incidence of fistula 40.3%. The history of anal pathology and the presence of symptoms in the postoperative review significantly increase the possibility of recurrence (p < 0.001). The fistula is statistically more frequent if the abscess recurs (p < 0.001) CONCLUSION: After drainage and debridement of an anal abscess, half of the patients relapse and 40% develop fistula especially in the first year, so longer follow-ups are not necessary. Endoanal ultrasound for the evaluation of the presence of fistula is highly questionable in the absence of signs or symptoms.

Preventing the recurrence of acute anorectal abscesses utilizing a loose seton: a pilot study

Introduction

This pilot study aimed to document our results of treating anorectal abscesses with drainage plus loose seton for possible coexisting high fistulas or drainage plus fistulotomy for low tracts at the same operation.

Methods

Drainage plus fistulotomy were performed only in cases with subcutaneous mucosa, intersphincteric, or apparently low transsphincteric fistula tracts. For all other cases with high transsphincteric fistula or those with questionable sphincter involvement, a loose seton was placed through the tract. Drainage only was carried out in 17 patients.

Results

Twenty-three patients underwent drainage plus loose seton. Drainage plus fistulotomy were performed in four cases. None of the patients developed recurrent abscess during a follow-up of 12 months. Not surprisingly, the incontinence scores were similar pre and post-operatively (p=0.564). Only minor complications occurred in 4 cases (14.8 percent). Secondary interventions following loose seton were carried out in 13 patients (48.1 percent). At 12 months, drainage only was followed by 10 recurrences (58.8 percent; p<0.0001, compared with concomitant surgery).

Conclusion

Concomitant loose seton treatment of high fistula tracts associated with anorectal abscess prevents abscess recurrence without significant complications or disturbance of continence. Concomitant fistulotomy for associated low fistulas also aids in the same clinical outcome. Concomitant fistula treatment with the loose seton may suffice in treating the whole disease process in selected cases. Even in patients with high fistula tracts, the loose seton makes fistula surgery simpler with a mature tract. Abscess recurrence is high after drainage only.

Can Perianal Fistula Be Treated Non-surgically with Platelet-Rich Fibrin Sealant?

INTRODUCTION

In the last 20 years, various procedures have been suggested for the treatment of anal fistula whilst minimising anal sphincter injury and preserving optimal function. Since 2011, patients at our hospital have been treated for anal fistula by means of platelet-rich fibrin plugs. To do so, three different application techniques have been used, the most recent of which is a non-surgical approach. In this paper, we compare and contrast the results obtained by each of these three techniques.

MATERIAL AND METHOD

This study compares three procedures in which the anal fistula was sealed using platelet-rich fibrin: for the patients in group A, the plug was surgically inserted, under anaesthesia, and traditional methods were used to curette the fistula tract and close the internal orifice; for those in group B, the plug was surgically inserted, under anaesthesia, after curettage of the fistula tract using a graduated set of cylindrical curettes, and the internal orifice was closed as before; and for those in group C, the plug was inserted during outpatient consultation, without anaesthesia, without curettage and without closure of the internal orifice.

RESULTS

The patients in the three groups were homogeneous in terms of sex, age, ASA classification, location of the fistula and previous insertion of the seton. There were no significant differences in morbidity or postoperative continence. However, there was a statistically significant difference in the outcomes achieved, in favour of group B, while groups A and C obtained similar results.

CONCLUSIONS

Outpatient treatment of perianal fistula is totally innocuous. It is a very low cost procedure and the results obtained are highly acceptable (similar to those of the surgical insertion of a plug, with traditional curettage). Therefore, we believe this approach should be considered a valid initial treatment for perianal fistula, reserving surgical treatment (curettage and sealing using a cylindrical-curette kit) for cases in which this initial method is unsuccessful. This would avoid many complications and achieve considerable financial savings for the health system.

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.

Japanese Practice Guidelines for Anal Disorders II. Anal fistula

Anal fistulas usually result from an anal gland infection in the intersphincteric space, which is caused by bacteria entering through the anal crypt (cryoptglandular infection). Reports of anal fistulas have been as high as 21 people in 100,000. Anal fistulas are 2-6 times more prevalent in males than females, with the condition occurring most frequently in patients in their 30s and 40s. Anal abscess symptoms include sudden onset of anal pain, swelling, redness, and fever. Purulent discharge or intermittent perianal swelling and pain are most often consistent with anal fistula symptoms. Methods for diagnosing anal fistulas include visual inspection, palpation, digital examination, anoscopic examination, barium enema, fistulography, as well as imaging, such as ultrasound, CT, and MRI. Parks classification is widely adapted in the West; however, Japan usually employs Sumikoshi classification. Antibiotics should be administered in cases of perianal abscess with surrounding cellulitis, or concomitant systemic disease, or those not alleviated by incision and drainage. The site and size of incision and drainage depend upon the abscess type and location. Incisions should be performed taking care not to damage the sphincter muscles and with possible future fistula surgery in mind. As spontaneous recovery is rare, except in the case of children, surgery is the principle approach to anal fistulas. Several approaches are utilized for anal fistulas. A specific procedure may be chosen depending upon curability and anal function. Postsurgical outcomes vary from study to study. Fecal incontinence may occur after fistula surgery, but reports vary.

The treatment of anal fistula: second ACPGBI Position Statement - 2018

It is over 10 years since the first ACPGBI Position Statement on the management of anal fistula was published in 2007. This second edition is the result of scrutiny of the literature published during this time; it updates the original Position Statement and reviews the published evidence surrounding treatments for anal fistula that have been developed since the original publication.

Is fistulotomy still the gold standard in present era and is it highly underutilized?: An audit of 675 operated cases

AIM

Due to fear of incontinence, fistulotomy perhaps remains highly underutilized. The aim was to analyze the efficacy of fistulotomy in a large cohort, to assess the magnitude of underutilization of fistulotomy by current classifications and to identify the subgroup in whom the fistulotomy should be done.

METHODS

All consecutive operated patients of fistula-in-ano were included in the study retrospectively. The fistulas were classified as per existing classifications-Parks, St James University Hospital (SJUH) and Garg classification. Smaller grades of each classification (Parks I, SJUH I-II, Garg I-II) were expected to be simple fistulas and thus amenable to fistulotomy. Objective incontinence scores were done preoperatively and postoperatively.

RESULTS

675 patients were operated over a 5.5 year period (median-27 months). 25 patients were excluded. Fistulotomy was done in 353/650 (54.3%) patients and sphincter-saving procedures (SSP) performed in 297/650 (45.7%) patients. After fistulotomy, 346/353 (98%) fistulas healed after the first operation. Seven patients with recurrent fistula were cured after a repeat fistulotomy surgery. Thus the overall healing rate was 353/353 (100%). There was no significant change in continence scores. The 353 fistulotomy patients were classified as per different classifications- Parks (I-225,II-112,III-16,IV-0), SJUH(I-138,II-87,III-47,IV-65,V-16) and Garg (I-188,II-165,III-0,IV-0,V-0). 123 (36.3%) patients who could undergo fistulotomy successful were erroneously classified as complex fistula by Parks and SJUH classifications. Garg classification accurately identified all 353/353 (100%) patients were amenable to fistulotomy.

CONCLUSIONS

Fistulotomy is a safe procedure with remarkably high success rate (100%) and is gold-standard in majority of patients (>50%). Parks and SJUH classifications are inaccurate in selecting patients for fistulotomy. Garg classification predicts amenability to fistulotomy with very high accuracy.

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.

Pathogenesis and persistence of cryptoglandular anal fistula: a systematic review

Anal fistulas continue to be a problem for patients and surgeons alike despite scientific advances. While patient and anatomical characteristics are important to surgeons who are evaluating patients with anal fistulas, their development and persistence likely involves a multifaceted interaction of histological, microbiological, and molecular factors. Histological studies have shown that anal fistulas are variably epithelialized and are surrounded by dense collagen tissue with pockets of inflammatory cells. Yet, it remains unknown if or how histological differences impact fistula healing. The presence of a perianal abscess that contains gut flora commonly leads to the development of anal fistula. This implies a microbiological component, but bacteria are infrequently found in chronic fistulas. Recent work has shown an increased expression of proinflammatory cytokines and epithelial to mesenchymal cell transition in both cryptoglandular and Crohn's perianal fistulas. This suggests that molecular mechanisms may also play a role in both fistula development and persistence. The aim of this study was to examine the histological, microbiological, molecular, and host factors that contribute to the development and persistence of anal fistulas.

Simulation-based sample-sizing and power calculations in logistic regression with partial prior information

There have been many approximations developed for sample sizing of a logistic regression model with a single normally-distributed stimulus. Despite this, it has been recognised that there is no consensus as to the best method. In pharmaceutical drug development, simulation provides a powerful tool to characterise the operating characteristics of complex adaptive designs and is an ideal method for determining the sample size for such a problem. In this paper, we address some issues associated with applying simulation to determine the sample size for a given power in the context of logistic regression. These include efficient methods for evaluating the convolution of a logistic function and a normal density and an efficient heuristic approach to searching for the appropriate sample size. We illustrate our approach with three case studies. Copyright © 2016 John Wiley & Sons, Ltd.

Complex anal fistula remains a challenge for colorectal surgeon

AIM

Anal fistula is a common proctological problem to both patient and physician throughout surgical history. Several surgical and sphincter-sparing approaches have been described for the management of fistula-in-ano, aimed to minimize the recurrence and to preserve the continence. We aimed to systematically review the available studies relating to the surgical management of anal fistulas.

MATERIAL AND METHODS

A Medline search was performed using the PubMed, Ovid, Embase, and Cochrane databases to identify articles reporting on fistula-in-ano management, aimed to find out the current techniques available, the new technologies, and their effectiveness in order to delineate a gold standard treatment algorithm.

RESULTS

The management of low anal fistulas is usually straightforward, given that fistulotomy is quite effective, and if the fistula has been properly evaluated, continence disturbance is minimal. On the contrary, high complex fistulas are challenging, because cure and continence are directly competing priorities.

CONCLUSIONS

Conventional fistula surgery techniques have their place, but new technologies such as fibrin glues, dermal collagen injection, the anal fistula plugs, and stem cell injection offer alternative approaches whose long-term efficacy needs to be further clarified in large long-term randomized trials.

Operative treatment of perianal abscess

Perianal abscess is a common disease. Due to the special anatomical position, management of perianal abscess is still controversial. Especially, the treatment of deep perianal abscess is very difficult, because it is difficult to confirm the relationship among internal opening, extent of deep anorectal abscess and anorectal sphincters. Correct treatment of the internal opening and extent of deep anorectal abscess is the key to success. Treating the fistula and the abscess at the same time by incision and drainage may reduce the likelihood of recurrent abscess and the need for repeat surgery. However, this could affect sphincter function in some patients who may not later develop a fistula-in-ano. The results of current treatments for perianal abscess are not very satisfactory. More studies are needed in future.

Acute abscess with fistula: long-term results justify drainage and fistulotomy

Conventional treatment of anal abscess by a simple drainage continues to be routine in many centers despite retrospective and randomized data showing that primary fistulotomy at the time of abscess drainage is safe and efficient. The purpose of this study is to report the long-term results of fistulotomy in the treatment of anal abscesses. This is a prospective nonrandomized study of 165 consecutive patients treated for anal abscess in University Hospital Hassan II, Fez, Morocco, between January 2005 and December 2010. Altogether 102 patients were eligible to be included in the study. Among them, 52 were treated by a simple drainage and 50 by drainage with fistulotomy. The results were analyzed in terms of recurrence and incontinence after a median follow-up of 3.2 years (range 2-6 years). The groups were comparable in terms of age, gender distribution, type and size of abscess. The recurrence rate after surgery was significantly higher in the group treated by drainage alone (88 %) compared to other group treated by drainage and fistulotomy (4, 8 %) (p < 0.0001). However, there was a tendency to a higher risk of fecal incontinence in the fistulotomy group (5 % vs 1 %), although this difference was not significant (p = 0.27). In the group treated by drainage and fistulotomy, high fistula tract patients are more prone to develop incontinence and recurrence, mainly within the first year. A long-term follow-up seems not to influence the results of fistulotomy group. These findings confirm that fistulotomy is an efficient and safe treatment of anal abscess with good long-term results. An exception is a high fistula, where fistulotomy may be associated with a risk of recurrence and incontinence.

German S3 guideline: anal abscess

BACKGROUND

The incidence of anal abscess is relatively high, and the condition is most common in young men.

METHODS

A systematic review of the literature was undertaken.

RESULTS

This abscess usually originates in the proctodeal glands of the intersphincteric space. A distinction is made between subanodermal, intersphincteric, ischioanal, and supralevator abscesses. The patient history and clinical examination are diagnostically sufficient to establish the indication for surgery. Further examinations (endosonography, MRI) should be considered in recurrent abscesses or supralevator abscesses. The timing of the surgical intervention is primarily determined by the patient's symptoms, and acute abscess is generally an indication for emergency treatment. Anal abscesses are treated surgically. The type of access (transrectal or perianal) depends on the abscess location. The goal of surgery is thorough drainage of the focus of infection while preserving the sphincter muscles. The wound should be rinsed regularly (using tap water). The use of local antiseptics is associated with a risk of cytotoxicity. Antibiotic treatment is only necessary in exceptional cases. Intraoperative fistula exploration should be conducted with extreme care if at all; no requirement to detect fistula should be imposed. The risk of abscess recurrence or secondary fistula formation is low overall, but they can result from insufficient drainage. Primary fistulotomy should only be performed in case of superficial fistulas and by experienced surgeons. In case of unclear findings or high fistulas, repair should take place in a second procedure.

CONCLUSION

In this clinical S3 guideline, instructions for diagnosis and treatment of anal abscess are described for the first time in Germany.

Recent progress in surgical management of perianal abscess

Perianal abscess is one of the common rectal diseases. Surgical management is still the most effective way. Surgical methods have roughly experienced three phases of landmark development: initially simple incision/drainage combined with surgery for the second time when fistula-in-ano is formed, followed by primary curative incision, and finally sphincter-preserving surgery, which reinforces the importance of protecting the function of the anus. The use of these surgical methods not only reduces the recurrence of abscess and the incidence of anal fistula, but also protects the fine function and integrity of the anus, greatly reducing the pain in patients and raising their quality of lives.

Why do we have to review our experience in managing cases with idiopathic fistula-in-ano regularly?

“Why do we have to review our experience in managing idiopathic fistula-in-ano regularly?” In order to answer this apparently simple question, we reviewed our clinical and surgical cases and most important relevant literature to find a rational and scientific answer. It would appear that whatever method you adopt in fistula management, there is a price to pay regarding either rate of recurrence (higher with conservative methods) or impairment of continence (higher with traditional surgery). Since, at the moment, reliable data to identify a treatment as a gold standard in the management of anal fistulas are lacking, the correct approach to this condition must consider all the anatomic and clinicopathological aspects of the disease; this knowledge joined to an eclectic attitude of the surgeon, who should be familiar with different types of treatment, is the only guarantee for a satisfactory treatment. As a conclusion, it is worthwhile to remember that adequate initial treatment significantly reduces recurrence, which, when it occurs, is usually due to failure to recognise the tract and primary opening at the initial operation.

The impact of specialist experience in the surgical management of perianal abscesses

Perianal abscesses are one of the most common general surgical emergencies and the management of this can be variable. The aim of our study was to assess the management strategy used by different grades of surgeons in the surgical management of an acute perianal abscess.

MATERIAL AND METHODS

A retrospective analysis was carried out of all patients presenting with an abscess in the perianal region over a two-year period from January 2006 to December 2007. Patient demographics and co-morbidities were noted. The management strategies of different grades of operating surgeon were analysed.

RESULTS

During the two-year period, 147 patients presented with a perianal abscess of whom 52 (28%) had recurrent abscess. Fistulae were identified in 30 patients, with more than half picked up by consultants (P = 0.00001). Consultants performed fistulotomy and Seton insertion in 50% and 17% of patients respectively, whilst registrars performed these procedures in only 4% and 8% of patients (p < 0.00001).

CONCLUSION

Whilst surgical management of the perianal abscess is one of the most common surgical emergency procedures performed by the surgical trainees, input from a senior clinician improves the identification and definitive management of an underlying fistula. This study reinforces the importance of involvement of senior surgeons in the management of this common condition.

Treatment of perianal sepsis and long-term outcome of recurrence and continence

AIM

The study investigated the fate of patients with perianal sepsis of cryptoglandular origin.

METHOD

All patients treated for perianal sepsis between January 1994 and December 2000 were retrospectively analysed regarding recurrence and faecal incontinence. Data collection was conducted by chart review and by telephone questionnaire using the Vaizey incontinence score.

RESULTS

One hundred seventy-three (58%) of 300 patients were available for follow-up at a median period of 121 (77-171) months. Fistula-in-ano was diagnosed in 156 (90%) patients. After a single surgical procedure, 55 (32%) patients had no recurrence of perianal sepsis. In 118 (68%), recurrence required multiple procedures (median 3, range 2-19). If only a single incision and drainage was performed (n = 10, 6%), no faecal incontinence occurred. Drainage with fistulotomy (n = 45, 26%) induced mild incontinence in 9% and severe incontinence in 4%. After multiple procedures that were required in 118 (68%) patients, mild and severe faecal incontinence was found in 16% and 4% of them, respectively.

CONCLUSION

Treatment of anal sepsis is associated with a high recurrence rate and a substantial risk of faecal incontinence.

Prognostic factors for recurrence following the initial drainage of an anorectal abscess

PURPOSE

It is well known that recurrent abscesses and anal fistulas may develop following incision and drainage. In this study, the prognostic factors for recurrence of anorectal abscess were retrospectively examined following initial drainage.

METHODS

Between November 2003 and April 2008, 205 patients with a diagnosis of anorectal abscess underwent initial incision and drainage at our hospital. We included only patients experiencing anorectal abscess for the first time, which represent the majority of anorectal abscess patients seen in regular clinical practice.

RESULTS

Of the total of 205 subjects, 74 experienced recurrence and 131 were cured (without recurrence). An investigation on the prognostic factors for recurrence revealed that the time from disease onset to incision was the only significant prognostic factor (p = 0.001). Sex, age, body mass index, method of anesthesia, abscess location, anatomic classification, use of a drain, and comorbid diabetes mellitus had no influence on recurrence. The cumulative cure rates were 68.7% for 1 year, 64.2% for 2 years, and 63.5% for 3 years.

CONCLUSION

For patients undergoing incision and drainage of anorectal abscesses, obesity did not affect recurrence. Prompt incision of anorectal abscesses was important to avoid recurrence.

Tract length predicts successful closure with anal fistula plug in cryptoglandular fistulas

PURPOSE

Collagen anal fistula plug treatment of transsphincteric fistulas produces variable results. The purpose of our study was to determine whether long-tract fistulas (>4 cm) correlated with successful closure.

METHODS

All patients undergoing transsphincteric cryptoglandular fistula repair with anal fistula plugs were enrolled in a prospective database. Patients with Crohn's disease were excluded. Fistula tract length was measured intraoperatively by subtracting the remaining plug length from the original plug size. All procedures used standardized techniques and postoperative care pathways. The primary outcome was complete fistula closure assessed through both postoperative outpatient visits and a follow-up telephone questionnaire.

RESULTS

Forty-one patients with 42 fistula tracks were enrolled over a 39-month period. Complete closure was achieved in 18 of 42 (43%) fistulas at a mean follow-up of 25 months. Closure was not associated with gender, age, tract location, duration of seton, or length of follow-up. Successful closure was significantly associated with increased tract length, because fistulas longer than 4 cm were nearly 3 times more likely to heal compared with shorter fistulas ((14/23, 61%) vs (4/19, 21%), P = .004; relative risk = 2.8; 95% CI 1.14-7.03).

CONCLUSIONS

Anal fistula plug repair of cryptoglandular anorectal fistulas is more successful for long-tract fistulas. Although the overall success is modest, limiting surgical indications to fistulas exceeding 4 cm may maximize benefits of the plug technique.

Incision and drainage of perianal abscess with or without treatment of anal fistula

BACKGROUND

The perianal abscess is a common surgical problem. A third of perianal abscesses may manifest a fistula-in-ano which increases the risk of abscess recurrence requiring repeat surgical drainage. Treating the fistula at the same time as incision and drainage of the abscess may reduce the likelihood of recurrent abscess and the need for repeat surgery. However, this could affect sphincter function in some patients who may not have later developed a fistula-in-ano.

OBJECTIVES

We aimed to review the available randomised controlled trial evidence comparing incision and drainage of perianal abscess with or without fistula treatment.

SEARCH STRATEGY

Randomised trials were identified from MEDLINE, EMBASE, the Cochrane Library, and reference lists of published papers and reviews.

SELECTION CRITERIA

Trials comparing outcome after fistula surgery with drainage of perianal abscess compared with drainage alone were included in the review.

DATA COLLECTION AND ANALYSIS

The primary outcomes were recurrent or persistent abscess/fistula which may require repeat surgery and short-term and long-term incontinence. Secondary outcomes were duration of hospitalisation, duration of wound healing, postoperative pain, quality of life scores. For dichotomous variables, relative risks and their confidence intervals were calculated.

MAIN RESULTS

We identified six trials, involving 479 subjects, comparing incision and drainage of perianal abscess alone versus incision and drainage with fistula treatment. Metaanalysis showed a significant reduction in recurrence, persistent abscess/fistula or repeat surgery in favour of fistula surgery at the time of abscess incision and drainage (RR=0.13, 95% Confidence Interval of RR = 0.07-0.24). Transient manometric reduction in anal sphincter pressures, without clinical incontinence, may occur after treatment of low fistulae with abscess drainage. Incontinence at one year following drainage with fistula surgery was not statistically significant (pooled RR 3.06, 95% Confidence Interval 0.7-13.45) with heterogeneity demonstrable between the trials (Chi(2) =5.39,df=3, p=0.14, I(2) =44.4%).

AUTHORS' CONCLUSIONS

The published evidence shows fistula surgery with abscess drainage significantly reduces recurrence or persistence of abscess/fistula, or the need for repeat surgery. There was no statistically significant evidence of incontinence following fistula surgery with abscess drainage. This intervention may be recommended in carefully selected 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.

[Long-term follow-up of the treatment of high anal fistulas using fibrin glue]

AIM OF THE STUDY

Many of the treatments proposed for trans-sphincteric and suprasphincteric anal fistulas are complex and often associated with permanent damage to the sphincter mechanism. In this study, we evaluate the long-term stability of fistula closure using fibrin glue.

MATERIALS AND METHODS

Forty-five consecutive patients (mean age 41.5) underwent this procedure. Follow-up was obtained from all patients and their primary care physicians by January 1, 2008.

RESULTS

Mean follow-up was 67 months. All recurrences occurred in the first six months after the initial fibrin glue injection procedure; there were no late recurrences.

CONCLUSION

Long-term follow-up confirmed the safety, efficacy and durability of fibrin glue fistula closure.

Surgical management of anal fistulae: a systematic review

OBJECTIVE

The anal fistula has been a common surgical ailment reported since the time of Hippocrates but little systematic evidence exists on its management. We aimed to systematically review the available studies relating to the surgical management of anal fistulas.

METHOD

Studies were identified from PubMED, EMBASE, Cochrane Controlled Trials Register, ClinicalTrials.Gov and Current Controlled Trials. All uncontrolled, nonrandomized, retrospective studies, duplications or those unrelated to the surgical management of anal fistulas were excluded.

RESULTS

The search strategy revealed 443 trials. After exclusions 21 randomized controlled trials remained evaluating: fistulotomy vs fistulectomy (n = 2), seton treatment (n = 3), marsupialization (n = 2), glue therapy (n = 3), anal flaps (n = 3), radiosurgical approaches (n = 2), fistulotomy/fistulectomy at time of abscess incision (n = 5) and intra-operative anal retractors (n = 1). Two meta-analyses evaluating incision and drainage alone vs incision + fistulotomy were obtained.

CONCLUSION

Marsupialization after fistulotomy reduces bleeding and allows for faster healing. Results from small trials suggest flap repair may be no worse than fistulotomy in terms of healing rates but this requires confirmation. Flap repair combined with fibrin glue treatment of fistulae may increase failure rates. Radiofrequency fistulotomy produces less pain on the first postoperative day and may allow for speedier healing. Major gaps remain in our understanding of anal fistula surgery.

Common anorectal problems

Children, just as adults, have a variety of common anorectal problems that can be quite bothersome. The presentation of these problems may be age-specific. Abscesses, fistulas, and fissures appear more commonly in infants and young children, whereas hemorrhoids and pilonidal disease are more common in teens and young adults. Fissures often can be treated medically but may require surgical treatment with lateral internal sphincterotomy. Abscesses and fistulas are common in infant males, especially robust infants who are breastfed. They may resolve with medical therapy but anal fistulotomy is not infrequently required. Hemorrhoids are rare in young children but may be an issue for teenagers. Acute symptomatic lesions may require excision if local measures cannot control the symptoms. Finally, pilonidal disease is a difficult problem for the patient and the surgeon. Persistently symptomatic lesions demand some type of surgical treatment but wound healing is poor in the intergluteal cleft region. More extensive procedures requiring the transfer of fasciocutaneous flaps may be necessary to provide definitive relief. Anorectal problems in infants and children are frequent and bothersome. Although most are not associated with tremendous morbidity, they can lead to much patient and parent anxiety as well as frequent medical consultation until the problem is successfully treated or resolves.

Meta-analysis of randomized clinical trials comparing drainage alone vs primary sphincter-cutting procedures for anorectal abscess-fistula

BACKGROUND AND AIM

Concurrent definitive treatment of underlying fistulas from infected anal glands at the time when the anorectal abscesses are drained is controversial as this is associated with a higher incidence of faecal incontinence, failure and recurrence. This meta-analysis was conducted to determine the merits of drainage alone vs primary sphincter-cutting procedures (which includes fistulotomy and fistulectomy) for anorectal abscess-fistula.

METHODS

Medline, Embase and Cochrane Central Register of Controlled Trials database searches identified all randomized controlled trials using the keywords: anorectal abscess, anal sepsis, drainage, fistulotomy, fistulectomy or surgery from 1966 to 2004. The outcome variables analysed were recurrence, faecal continence and wound-healing times.

RESULTS

Five trials were considered suitable for the meta-analysis, with a total of 405 patients. Sphincter-cutting procedures for anorectal abscesses resulted in 83% reduction in recurrence rate [relative risk (RR) 0.17, 95% confidence interval (CI) 0.09-0.32, p<0.001]. However, there was a tendency to a higher risk of faecal incontinence to flatus and soiling when primary sphincter-cutting procedure was performed (RR 2.46, 95% CI 0.75-8.06, p=0.140).

CONCLUSION

There is no conclusive evidence if simple drainage or sphincter-cutting procedure is better in the treatment of anorectal abscess-fistula.

Controversies in the treatment of common anal problems

Treating common benign anal diseases has evolved towards more outpatient procedures with better outcome. However, minimizing post-procedure morbidities such as pain and the avoidance incontinence remain the most significant concerns. We introduce some controversies and highlight the developments in current surgical practice for the treatment of common anal problems.

Anal abscesses and fistulas

Anal abscesses and fistulas are a common part of surgical practice. Most abscesses simply need to be drained and most fistulas can be safely laid open. Excessive probing should not be attempted when draining abscesses as this may lead to iatrogenic fistulas. A small percentage of fistulas are complex and very challenging to manage. Management involves an accurate diagnosis and a balance between eradication of the fistula and maintenance of continence. A decision should be made, based on clinical evaluation and anal ultrasound (if available), whether the fistula can be laid open. If it cannot be laid open, a loose seton is placed and the sepsis is allowed to settle. Once the sepsis is quiescent, a definitive repair can be attempted. There are various techniques available including rectal advancement flap, fibrin glue and cutaneous flaps all of which are discussed.