Anal Fistula Research Articles

Value of apparent diffusion coefficient on MRI for prediction of histopathological type in anal fistula cancer.

The main histopathological types of anal fistula cancers are mucinous adenocarcinoma and tubular adenocarcinoma. The purpose of this study was to investigate the utility of the apparent diffusion coefficient (ADC) value in magnetic resonance imaging (MRI) to determine the histopathological type of an anal fistula cancer, and to investigate the relationship between ADC values and histopathological type (mucinous type or tubular carcinoma), clinical information, and surgical findings. We retrospectively identified 69 patients diagnosed with anal fistula cancer at our hospital from January 2013 to December 2021. Among them, we selected the patients diagnosed using the same 1.5-T MRI machine, underwent surgery, and a pathological sample was obtained during the operation. Finally, these 25 patients were selected for the analysis since they underwent the imaging scan using the same MRI machine. The ADC value was compared between mucinous and tubular adenocarcinomas, and between tumors at the Tis-T1-T2 and T3-T4 stages. Finally, 25 patients were selected. The mean age of the 25 patients included in the analysis was 60.8 ± 13.3 years and all were males. The median ADC of anal fistula cancers was 1.97 × 10-3 mm2/s for mucinous adenocarcinomas and 1.36 × 10-3 mm2/s for tubular adenocarcinomas; this difference was statistically significant (P < .01). Furthermore, the median ADC was 1.62 × 10-3 mm2/s for tumors in Tis-T1-T2 stages and 2.01 × 10-3 mm2/s for T3-T4 tumors (P = .02). The ADC value in MR images may predict the histopathological type and depth of anal fistula cancers. Also, the different ADC values between Tis-T1-T2 and T3-T4 tumors could help predict the classification of progression.

A Comparison of Laser and Fistulotomy Techniques in the Treatment of Fistula-in-Ano.

Background Anal fistulas are a common complication of perianal abscesses.The treatment of anal fistulas is challenging, with persistent and high recurrence rates. The aim of this study was to evaluate the efficacy and cost-effectiveness of laser ablation compared to fistulotomy in the treatment of anal fistulas. Materials and methods The patients were examined for external and internal openings of the fistula, its number, length, type, relationship with the sphincters, and any previous history of abscess or proctological surgery. The surgical procedures, complications, incontinence, recurrence, and recovery time were evaluated and compared between the two groups. The laser ablation group received an intermittent laser application at a wavelength of 1470 nmand 10 watts for three seconds, while the fistulotomy group underwent cutting of the fistula tract with electrocautery while keeping a stylet in place. Results A total of 253 patients were included in this retrospective study, with 149 patients undergoing fistulotomy and 104 patients undergoing laser ablation. The patients were evaluated based on the type, number, and location of internal and external openings, and the length of the fistula tract according to the Parks classification. The mean follow-up period was 9.0±4.3 months. The results showed that the laser group had a shorter time to return to work and less postoperative pain compared to the fistulotomy group. However, the recurrence rate was higher in the laser group. The recurrence rate was also found to be higher in patients with low transsphincteric fistulas and in patients with diabetes mellitus. Conclusion Our study findings indicate that while laser ablation may be associated with less pain and quicker recovery time, it may also have a higher recurrence rate compared to fistulotomy.We believe that laser ablation is a valuable option for surgeons to consider early on in the treatment process, especially in cases where fistulotomy is not suitable.

The management of complex fistula in ano by transanal opening of the intersphincteric space (TROPIS): short-term results.

Many methods have been used to treat complex fistulas, but no single technique has been considered standard. Damage to the sphincter may sometimes be unavoidable, and incontinence may be an important cause of morbidity. This study aimed to validate the results of transanal opening of the intersphincteric space (TROPIS), as a technique that avoids damaging the anal sphincter, in patients with complex fistula in ano. A prospective study was conducted among 35 consecutive patients with complex fistula in ano. After a preoperative magnetic resonance fistulogram, TROPIS was performed in all patients. The St. Mark's incontinence score was assessed preoperatively and postoperatively at 3 months. The tracts were intersphincteric in 16 patients, transsphincteric in 10, extrasphincteric in 2, and horseshoe in 3. Four patients had recurrent tracts (3 transsphincteric and 1 intersphincteric). A defined follow-up schedule was used. Curettage was done if postoperative pus drainage from the wound was noted. The fistula healed in 29 patients (82.86%) following TROPIS. The remaining 6 patients received curettage, with healing in 3 (overall healing rate, 91.4%). Patients who received curettage were followed for 3 months, and the outcome was labeled as healed or failed. The mean preoperative incontinence score was 0. One patient developed incontinence to gas postoperatively in week 2, but there was no significant change in the scores at 3 months postoperatively. The mean postoperative incontinence score was 0.02. TROPIS is an effective method for the treatment of complex fistula in ano, with minimal risk for incontinence.

The efficacy of Ksharsutra, Fistulectomy and Ligation of Intersphincteric Fistula Tract (LIFT) procedure in management of Fistula in ano a prospective observational study

BackgroundFistula in ano is always a troublesome condition for the clinician and the patients owing to its complexity, recurrences, and high morbidity since ancient times. There is no gold standard treatment modality to date documented in the literature for complex fistula in ano.Material and methodsWe enrolled 60 consecutive adult patients attending the surgical outpatient department of a tertiary care centre in India, diagnosed with complex fistula in ano. Among them, 20 each in the Ligation of intersphincteric fistula tract (LIFT), Fistulectomy andKsharsutra(Special medicated seton) group were respectively recruited randomly. A prospective observational study was conducted. The primary outcomes were postoperative recurrence and morbidity. Post-operative morbidity is measured in terms of postoperative pain, postoperative bleeding, pus discharge and post-operative incontinence. The result of the study were analysed after 6 months of follow-up by clinical examination at outpatient department and at 18 months follow up done telephonically.ResultsAt 6 months of follow-up, 2 patients (10%) had a recurrence in the Ligation of intersphincteric fistula tract procedure group, 3 patients (15%) in the fistulectomy group and 6 patients (30%) in Ksharsutra group, however 3(15%), 4(20%) and 9(45%) patients developed recurrence in Ligation of Intersphincteric fistula tract, Fistulectomy and Ksharsutra group respectively at 18 month of follow-up. The differences in the recurrence were not statistically significant.The mean Visual analogue score for postoperative pain after 24 h as well as after 48 h were statistically significant in Ligation of intersphincteric fistula tract versus Ksharsutra group (p < 0.05). The Visual analogue score for post–operative pain was also significant in the Ligation of the intersphincteric fistula tract versus the Fistulectomy group (p < 0.05). The patients treated via Fistulectomy and Ksharsutra had a higher proportion of bleeding (15%) as compared to the Ligation of intersphincteric fistula tract procedure. Postoperative morbidity was statistically significant between the Ligation of intersphincteric fistula tract versus the Ksharsutra and the Ligation of intersphincteric fistula tract versus Fistulectomy.ConclusionLigation of intersphincteric fistula tract had less postoperative morbidity compared to Fistulectomy and Ksharsutra procedure; although recurrence was less compared to other methods it was statistically not significant.

Individualized Treatmet and Suitable Management of Patients with Anal Fistulas

Individualized Treatmet and Suitable Management of Patients with Anal Fistulas

The use of a loose seton as a definitive surgical treatment for anorectal abscesses and complex anal fistulas.

There is no consensus regarding the standard treatment method for anorectal abscesses accompanied by anal fistulas and complex anal fistulas. Simultaneous surgical treatment of the underlying anal fistula with anorectal abscess drainage is controversial due to incontinence problems. We aimed to investigate the effectiveness of the loose seton method for the treatment of chronic anal fistulas and acute anorectal abscesses accompanied by anal fistula. In this retrospective study, 114 patients who were operated on in our clinic due to chronic anal fistulas and anorectal abscesses with an applied loose seton between 2020 and 2022 were included in the study. The patients were divided into 2 groups: those with chronic complex anal fistula and those with anorectal abscess accompanied by anal fistula. The groups were compared in terms of their continence status, rate of recurrence, recurrent abscess formation, postoperative pain scores, duration of operation, and demographic characteristics. Of the patients included in the study, 78 had a complex chronic anal fistula, and 36 had an anorectal abscess accompanied by an anal fistula. There were no differences between the demographic characteristics of the 2 groups. The mean seton dissociation time was 6.8 (3-19) months. Gas or stool leakage was not observed in patients during the mean follow-up period of 18 (6-30) months. There was no difference in postoperative continence levels between the 2 groups. No recurrent fistulas were observed in patients during the follow-up period. Recurrent abscesses were observed in 5 (13.9%) patients in the anorectal abscess group. Abscesses due to insufficient drainage were observed in 2 (2.6%) patients in the chronic fistula group. There was no significant difference in operation time between the 2 groups. A loose seton can be a safe and effective method for the treatment of abscesses. It is a painless surgical method that produces good results in the treatment of all types of abscesses.

Newer procedures need to demonstrate efficacy in high complex anal fistulas.

Newer procedures need to demonstrate efficacy in high complex anal fistulas.

Comparison of the modified ligation of intersphincteric fistula tract (LIFT) with Incision thread drawing method on serum IgA and IL-10 levels in high simple anal fistula.

To compare the effect of different techniques on serum immunoglobulin A and interleukin-10 in patients with high simple anal fistula. .The cross-sectional study was conducted at Dongyang People's Hospital, Weishan, China, from January 2019 to April 2021, and comprised patients with high simple anal fistula who were randomly and equally divided into Group A getting treatment with modified ligation of intersphincteric fistula tract, and Group B getting treatment with incision-thread-drawing method. Serum immunoglobulin A and interleukin-10 as well as the Wexner score were compared between the groups. Data was analysed using SPSS 25. Of the 140 patients, there were 70(50%) in each of the two groups. There were 125(89.2%) male subjects overall. The mean age in Group A was 38.91±8.91 years, while in Group B it was 38.20±8.51. Mean hospital stay in Group A was shorter than that in Group B (p<0.001). Mean serum immunoglobulin A and interleukin-10 values were not significantly different at baseline, but on day 7 post-surgery, the difference was significant between the groups (p<0.05). Likewise, Wexner score was significantly different at 3 months post-surgery (p<0.05). There was no significant difference in the incidence of postoperative complications between the groups (p=0.730). The modified ligation of intersphincteric fistula tract method was found to be a better option in the management of patients with high simple anal fistula.

Platelet-rich plasma in the treatment of anal fistula: a systematic review and meta-analysis.

To analyse the safety and effectiveness of platelet-rich plasma (PRP) in anal fistula patients. Online databases including PubMed, Embase, Cochrane Library, and Web of Science were searched from inception to December 5, 2022, for eligible studies about evaluating the efficacy of platelet-rich plasma (PRP) in treating anal fistula. Literature search, screening, data extraction, and quality assessment were carried out by two independent investigators. The overall cure rate, the complete cure rate, the recurrence rate, and the adverse event rate with their 95% confidence intervals (95% CI) were the primary calculation indexes. Subgroup analyses were conducted primarily according to whether PRP was combined with other treatments. Softwares of MedCalc 18.2 and Review Manager 5.3 were used for meta-analysis. A total of 14 studies with 514 patients were included in the meta-analysis. The overall cure rate of 14 studies was 72.11% (95% CI 0.64-0.79). The cure rate of PRP alone was 62.39% (95% CI 0.55-0.69). The combined cure rate of PRP with other treatments was 83.12% (95% CI 0.77-0.88). The cure rate of interventions involving PRP were superior to the cure rate of surgery methods without using PRP significantly in the 4 randomized controlled studies (RR = 1.30, 95% CI 1.10-1.54, p = 0.002). The complete cure rate of the 8 studies was 66.37% (95% CI 0.52-0.79). The recurrence rate of the 12 studies was 14.84% (95% CI 0.08-0.24). The adverse event rate of the 12 studies was 6.31% (95% CI 0.02-0.12). PRP showed favorable safety and effectiveness in the treatment of anal fistula, especially combined with other treatment procedures.

Surgery of Simple and Complex Anal Fistulae in Adults: A Review of the Literature for Optimal Surgical Outcomes.

Anal fistulas are common anorectal conditions, and surgery is the primary treatment option. In the last 20 years of literature, there exist a large number of surgical procedures, especially for the treatment of complex anal fistulas, as they present more recurrences and continence problems than simple anal fistulas. To date, there are no guidelines for choosing the best technique. We conducted a recent literature review, mainly the last 20 years, based on the PubMed and Google Scholar medical databases, with the goal of identifying the surgical procedures with the highest success rates, lowest recurrence rates, and best safety profiles. Clinical trials, retrospective studies, review articles, comparative studies, recent systematic reviews, and meta-analyses for various surgical techniques, as well as the latest guidelines of the American Society of Colon and Rectal Surgeons, the Association of Coloproctology of Great Britain and Ireland, and the German S3 guidelines on simple and complex fistulas were reviewed. According to the literature, there is no recommendation for the optimal surgical technique. The etiology, complexity, and many other factors affect the outcome. In simple intersphincteric anal fistulas, fistulotomy is the procedure of choice. In simple low transsphincteric fistulas, the patient's selection is crucial in order to perform a safe fistulotomy or another sphincter-saving technique. The healing rate in simple anal fistulas is higher than 95% with low recurrence and without significant postoperative complications. In complex anal fistulas, only sphincter-saving techniques should be used; the optimal outcomes are obtained by the ligation of the intersphincteric fistulous tract (LIFT) and rectal advancement flaps. Those techniques assure high healing rates of 60-90%. The novel technique of the transanal opening of the intersphincteric space (TROPIS) is under evaluation. The novel sphincter-saving techniques of fistula laser closure (FiLac) and video-assisted anal fistula treatment (VAAFT) are safe, with reported healing rates ranging from 65% to 90%. Surgeons should be familiar with all sphincter-saving techniques in order to face the variability of the fistulas-in-ano. Currently, there is no universally superior technique that can treat all fistulas.

Transanal Opening of Intersphincteric Space: A Novel Procedure to Manage Highly Complex Anal Fistulas.

1 Indus Super Specialty Hospital, Mohali, India 2 Garg Fistula Research Institute, Panchkula, India 3 SSRD MRI Imaging Center, Chandigarh, India Funding/Support: None reported. Financial Disclosures: None reported. Presented at the (1) annual meeting of American Society of Colon Rectum Surgeons on June 3, 2019 at Cleveland, OH; (2) the annual meeting of American Society of Colon Rectum Surgeons on May 22 2018 at Nashville, TN; (3) the annual meeting of American Society of Colon Rectum Surgeons on June 14, 2017 at Seattle, WA; and 4) the annual meeting of European Society of Colo Proctology (ESCP) on September 28, 2016 at Milan, Italy. Correspondence: Pankaj Garg, M.B.B.S., Garg Fistula Research Institute 1042, Sector-15, Panchkula, Haryana-134113 India. Email: [email protected]

The risk factors for failure and recurrence of LIFT procedure for fistula in ano.

Fistula in ano (FIA) is a common anorectal problem. There are several techniques that have been used for treatment; however, all of them carry risks of recurrence and incontinence. Ligation intersphincteric fistula tract (LIFT) is a type of treatment with a promising result of preserving the anal sphincter function. This study aimed to evaluate the outcome and risk factor of LIFT failure and to demonstrate the pattern of recurrence. The research funding was supported by Rajavithi Hospital. From January 2015 to January 2020, there were 250 cases of fistula in ano operations. A total of 148 patients underwent LIFT operation. The patients' average age was 39.72 ± 10.55 years and the average follow-up period was 111.86 ± 79.73 days. The average time to diagnose the recurrence was 99.12 ± 30.08 days. In addition, average time to perform a surgery after the diganosis was 64.67 ± 25.76 days. The study's analyses used data on age, sex, type of fistula, operative intervention, healing time, reinterventions, and recurrence. There were 22.97% of recurrence among 148 LIFT patients. Half of the patients who underwent the operation had a preoperative imaging study with MRI or endoanal ultrasonography in the first time due to the complexity of the disease. Factors associated with operation failure were collection, fistula tract size more than 5 millimeters, and the failure of ligating the tract in one attempt. LIFT procedure is one of the several sphincter saving procedures to treat FIA. Recurrence is related with the complexity of the disease. Most of the recurrence is diseases that are easier to treat, such as performing a re-operation or fistulotomy.

Conference report: Third annual young researcher forum of the Japan Society of Medical and Pharmaceutical Sciences for Traditional Medicine

AbstractFour young researchers presented their studies in the field of traditional Japanese herbal medicine (Wakan‐yaku) at the third annual young researcher forum entitled “Respecting and Breaking Traditions,” held 1 week before the 2022 annual meeting of the Japan Society of Medical and Pharmaceutical Sciences for Traditional Medicine. Dr. Yokogawa presented her research focusing on the mechanism of the Ayurveda drug‐eluting string, Kshara Sutra, in treating anal fistulas, reporting on its effects on the anal tissue in an anal fistula rat model and its antibacterial activity against Escherichia coli and Staphylococcus aureus, the causative organisms of anal fistulas. Mr. Nakamichi presented his research focusing on the relationship between the efficacy of Kampo medicines with anti‐obesity effects and intestinal microbiota composition. His results partially revealed that bofutsushosan and boiogito affect lipid metabolism in mice and correlate with the intestinal microbiota composition. Dr. Manse reported the anti‐inflammatory activity of diterpenoid components in Enmei‐so (Isodonis Herba), revealing its novel inhibitory activity on nitric oxide released from activated macrophages and on inflammatory cytokines, and identified active components contributing to the inhibition and the mechanism of action. Mr. Yoshikawa reported the anticancer activity of small molecular compounds isolated from the medicinal plants, Valeriana fauriei and Hypericum erectum. His results suggest that five compounds may increase the sensitivity of human cervical carcinoma cells to adriamycin via HSP105 expression suppression. The event was conducted online, and included 78 participants. We intend to hold and improve this forum in 2023 and the future.

Patient with suspected severe acute respiratory syndrome coronavirus 2 infection with successful emergency surgery for ulcerative colitis-associated toxic megacolon

BackgroundIn patients with acute severe ulcerative colitis with concomitant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the treatment strategy should consider the presence of pneumonia, respiratory status, and the severity of the ulcerative colitis (UC). We report a case of a 59-year-old man with SARS-CoV-2 infection who was diagnosed with toxic megacolon caused by UC.Case presentationPreoperative computed tomography scanning of the chest showed ground-glass opacities. The patient was treated conservatively until the pneumonia improved, but developed bleeding and liver dysfunction associated with UC. As the patient’s condition worsened, emergency surgery with subtotal colorectal resection, ileostomy, and rectal mucous fistula creation was performed while undertaking adequate infection control measures. Intraoperatively, contaminated ascites was observed, and the intestinal tract was markedly dilated and fragile. Nevertheless, the postoperative outcome was positive, with no pulmonary complications. The patient was discharged on postoperative day 77.ConclusionsThe COVID-19 pandemic presented challenges in surgical scheduling. Patients with SARS-CoV-2 infection required close monitoring for postoperative pulmonary complications.

First experience with highly vascularized lateral flap in patients with trans- and extrasphincter rectal fistula

In NMRC coloproctology a surgical method of treatment of the fistula of the rectum with the help of highly vascularized lateral flap (VLF) was developed. Currently 28 patients with trans and extrasphincter fistulas are included, both without and with the presence of purullent-inflammatory process in the surrounding tissue. The observation period was 1–8 months (Me = 4 [1.75; 5.5]). The disease relapsed in 6 (21.4 %) cases. Conclusion: the preliminary results of VLF use are encouraging, the low pain intensity and the intactness of the anal sphincter indicate a low traumatic and sphinctersaving nature of the operation. In addition, the study showed the possibility of using VLF even in the presence of purulent accumulations, which were previously contraindications to the use of plastic techniques as a one-stage treatment.

Clinical features and independent predictors of postoperative refractory trauma to anal fistula combined with T2DM: A propensity score-matched analysis-retrospective cohort study.

Refractory wound is a common postoperative complication in anal fistula surgery, when combined with type 2 diabetes mellitus (T2DM) it presents a slower recovery time and more complex wound physiology. The study aims to investigate factors associated with wound healing in patients with T2DM. 365 T2DM patients who underwent anal fistula surgery at our institution were recruited from June 2017 to May 2022. Through propensity score-matched (PSM) analysis, multivariate logistic regression analysis was applied to determine independent risk factors affecting wound healing. 122 pairs of patients with no significant differences were successfully established in matched variables. Multivariate logistic regression analysis revealed that uric acid (OR: 1.008, 95% CI: 1.002-1.015, p = 0.012), maximal fasting blood glucose (FBG) (OR: 1.489, 95% CI: 1.028-2.157, p = 0.035) and random intravenous blood glucose (OR: 1.130, 95% CI: 1.008-1.267, p = 0.037) elevation and the incision at 5 o'clock under the lithotomy position (OR: 3.510, 95% CI: 1.214-10.146, p = 0.020) were independent risk factors for impeding wound healing. However, neutrophil percentage fluctuating within the normal range can be considered as an independent protective factor (OR: 0.906, 95% CI: 0.856-0.958, p = 0.001). After executing the receiver operating characteristic (ROC) curve analysis, it was found that the maximum FBG expressed the largest under curve area (AUC), glycosylated hemoglobin (HbA1c) showed the strongest sensitivity at the critical value and maximum postprandial blood glucose (PBG) had the highest specificity at the critical value. To promote high-quality healing of anal wounds in diabetic patients, clinicians should not only pay attention to surgical procedures but also take above-mentioned indicators into consideration.

Deep remission improves the quality of life of patients with Crohn's disease and anoperineal fistula treated with darvadstrocel: results of a French pilot study.

The injection of allogeneic adipose tissue-derived mesenchymal stem cells (MSC) into anal fistulas in patients with Crohn's disease has never been evaluated in "real-life" conditions in France. We prospectively studied the first patients receiving MSC injections at our center and undergoing 12months of follow-up. The primary endpoint was the clinical and radiological response rate. The secondary endpoints were symptomatic efficacy, safety, anal continence, quality of life (Crohn's anal fistula-quality of life scale, CAF-QoL), and predictive factors of success. We included 27 consecutive patients. The complete clinical and radiological response rates at M12 were 51.9% and 50%, respectively. The combined complete clinical-radiological response (deep remission) rate was 34.6%. No major adverse effects or changes in anal continence were reported. The perianal disease activity index decreased from 6.4 to 1.6 (p < 0.001) for all patients. The CAF-QoL score also decreased from 54.0 to 25.5 (p < 0.001). At the end of the study, M12, the CAF-QoL score was significantly lower only in patients with a complete combined clinical-radiological response relative to those without a complete clinical-radiological response (15.0 versus 32.8, p = 0.01). Having a multibranching fistula and infliximab treatment were associated with a combined complete clinical-radiological response. This study confirms reported efficacy data for the injection of MSC for complex anal fistulas in Crohn's disease. It also shows a positive impact on the quality of life of patients, particularly those for whom a combined clinical-radiological response was achieved.

Use of autologous adipose stem cell for the treatment of recurring and complex anal fistula

Use of autologous adipose stem cell for the treatment of recurring and complex anal fistula

The Optimal Primary Treatment for Pediatric Perianal Abscess and Anal Fistula: A Systemic Review and Meta-Analysis

BackgroundPerianal abscesses and anal fistulas are common. The principle of intention-to-treat has not been considered in previous systemic reviews. Thus, the comparison between primary and post-recurrence management was confused, and the recommendation of primary treatment is obscure. The current study aims to identify the optimal initial treatment for pediatric patients. MethodsUsing PRISMA guidelines, studies were identified from MEDLINE, EMBASE, PubMed, Cochrane Library, and Google Scholar without any language or study design restriction. The inclusion criteria include original articles or articles with original data, studies of management for a perianal abscess with or without anal fistula, and patient age of <18 years. Patients with local malignancy, Crohn's disease, or other underlying predisposing conditions were excluded. Studies without analyzing recurrence, case series of <5, and irrelevant articles were excluded in the screening stage. Of the 124 screened articles, 14 articles had no full texts or detailed information. Articles written in a language other than English or Mandarin were translated by Google Translation first and confirmed with native speakers. After the eligibility process, studies that compared identified primary managements were then included in the qualitative synthesis. ResultsThirty-one studies involving 2507 pediatric patients met the inclusion criteria. The study design consisted of two prospective case series of 47 patients and retrospective cohort studies. No randomized control trials were identified. Meta-analyses for recurrence after initial management were performed with a random-effects model. Conservative treatment and drainage revealed no difference (Odds ratio [OR], 1.222; 95% Confidential interval [CI]: 0.615–2.427, p = 0.567). Conservative management had a higher risk of recurrence than surgery without statistical significance (OR 0.278, 95% CI: 0.109–0.707, p = 0.007). Compared with incision/drainage, surgery can prevent recurrence remarkably (OR 4.360, 95% CI: 1.761–10.792, p = 0.001). Subgroup analysis of different approaches within conservative treatment and operation was not performed for lacking information. ConclusionStrong recommendations cannot be made due to the lack of prospective or randomized controlled studies. However, the current study based on real primary management supports initial surgical intervention for pediatric patients with perianal abscesses and anal fistula to prevent recurrence. Level of evidenceType of study: Systemic review; Evidence level: Level II.

Fistula-Associated Anal Adenocarcinoma: A 20-Year Single-Center Experience.

Fistula-associated anal adenocarcinoma (FAAC) is a rare consequence in patients with long-standing perianal fistulas. A paucity of data are available for this patient collective, making clinical characterization and management of this disease difficult. This study aimed to describe a single-center experience with FAAC patients, their clinical course, and histopathological and molecular pathological characterization. All patients receiving surgery for an anal fistula in 1999-2019 at a tertiary university referral hospital were included in this retrospective analysis. Patients with FAAC were eligible for histopathological analysis, including immunohistochemistry and molecular profiling. This study included 1004 patients receiving surgical treatment for an anal fistula, of whom 242 had an underlying inflammatory bowel disease (IBD). Ten patients were diagnosed with a fistula-associated anal carcinoma (1.0%), and six of these patients had an FAAC (0.6%). The mean overall survival of FAAC patients was 24 ± 3 months. FAAC immunohistochemistry revealed positive staining for CK20, CDX2 and MUC2, while stainings for CK5/6 and CK7 were negative. All FAAC specimens revealed microsatellite stability. Molecular profiling detected mutations in 35 genes, with the most frequent mutations being TP53, NOTCH1, NOTCH3, ATM, PIK3R1 and SMAD4. FAAC is rare but associated with poor clinical outcome. Tissue acquisition is crucial for early diagnosis and therapy and should be performed in long-standing, non-healing, IBD-associated fistulas in particular. The immunophenotype of FAAC seems more similar to the rectal-type mucosa than the anal glands.