The comparison of magnetic resonance and fluoroscopic imaging options in the preoperative assessment of boys with anorectal malformations and a colostomy.

BACKGROUND: In recent decades, magnetic resonance imaging (MRI) has gained prominence as a standard diagnostic method for preoperative assessment in patients with anorectal malformations and a colostomy, with the potential to replace the classic fluoroscopic distal pressure colostogram (FDPC). Three MRI techniques are available: MRI-distal pressure colostogram with gadolinium (MRI-DPCG) or saline (MRI-DPCS) instillation into the colostomy and native MRI without colostomy instillation. OBJECTIVE: To evaluate and compare the diagnostic accuracy of MRI (native MRI, MRI-DPCG and MRI-DPCS) in the preoperative workup of boys with an anorectal malformation and a colostomy and to compare it to FDPC. MATERIALS AND METHODS: Sixty-two boys with preoperative MRI using one of the three approaches and 43 with FDPC met the inclusion criteria for this retrospective study. The presence and localization of rectal fistulas according to the Krickenbeck classification were evaluated and compared with intraoperative findings. RESULTS: The accuracy of fistula detection for MRI in general (regardless of the technique), MRI-DPCS, MRI-DPCG, native MRI and FDPC was 95% (59/62, P<0.001), 100% (12/12, P=0.03), 100% (30/30, P<0.001), 85% (17/20, P=0.41) and 72% (31/43, P=0.82), respectively. The accuracy of describing fistula type in patients with a correctly detected fistula using these methods was 96% (45/47, P<0.001), 100% (9/9, P<0.001), 100% (23/23, P<0.001), 87% (13/15, P<0.001) and 67% (13/21, P=0.002), respectively. CONCLUSION: MRI is a reliable method for detecting and classifying fistulas in boys with an anorectal malformation and a colostomy and can be considered the modality of first choice for preoperative workup.

Perianal Fistulas Are Associated with Persistently Higher Direct Health Care Costs in Crohn's Disease: A Population-Based Study.

BACKGROUND: The economic impact of perianal fistulas in Crohn's disease (CD) has not been formally assessed in population-based studies in the biologic era. AIM: To compare direct health care costs in persons with and without perianal fistulas. METHODS: We performed a longitudinal population-based study using administrative data from Ontario, Canada. Adults (> 17 years) with CD were identified between 2007 and 2013 using validated algorithms. Perianal fistula positive "cases" were matched to up to 4 "controls" with CD without perianal fistulas based on age, sex, geographic region, year of CD diagnosis and duration of follow-up. Direct health care costs, excluding drug costs from private payers, were estimated annually beginning 5 years before (lookback) and up to 9 years after perianal fistula diagnosis (study completion) for cases and a standardized date for matched controls. RESULTS: A total of 581 cases were matched to 1902 controls. The annual per capita direct cost for cases was similar at lookback compared to controls ($2458 ± 6770 vs $2502 ± 10,752; p = 0.952), maximally greater in the first year after perianal fistulas diagnosis ($16,032 ± 21,101 vs $6646 ± 13,021; p < 0.001) and remained greater at study completion ($11,358 ± 17,151 vs $5178 ± 9792; p < 0.001). At perianal fistula diagnosis, the cost difference was driven primarily by home care cost (tenfold greater), publicly-covered prescription drugs (threefold greater) and hospitalizations (twofold greater), whereas at study completion, prescription drugs were the dominant driver (threefold greater). CONCLUSION: In our population-based cohort, perianal fistulas were associated with significantly higher direct healthcare costs at the time of perianal fistulas diagnosis and sustained long-term.

Rectal Prolapse Following Repair of Anorectal Malformation: Incidence, Risk Factors, and Management.

BACKGROUND: The incidence and optimal management of rectal prolapse following repair of an anorectal malformation (ARM) has not been well-defined. METHODS: A retrospective cohort study was performed utilizing data from the Pediatric Colorectal and Pelvic Learning Consortium registry. All children with a history of ARM repair were included. Our primary outcome was rectal prolapse. Secondary outcomes included operative management of prolapse and anoplasty stricture following operative management of prolapse. Univariate analyses were performed to identify patient factors associated with our primary and secondary outcomes. A multivariable logistic regression was developed to assess the association between laparoscopic ARM repair and rectal prolapse. RESULTS: A total of 1140 patients met inclusion criteria; 163 (14.3%) developed rectal prolapse. On univariate analysis, prolapse was significantly associated with male sex, sacral abnormalities, ARM type, ARM complexity, and laparoscopic ARM repairs (p < 0.001). ARM types with the highest rates of prolapse included rectourethral-prostatic fistula (29.2%), rectovesical/bladder neck fistula (28.8%), and cloaca (25.0%). Of those who developed prolapse, 110 (67.5%) underwent operative management. Anoplasty strictures developed in 27 (24.5%) patients after prolapse repair. After controlling for ARM type and hospital, laparoscopic ARM repair was not significantly associated with prolapse (adjusted odds ratio (95% CI): 1.50 (0.84, 2.66), p = 0.17). CONCLUSION: Rectal prolapse develops in a significant subset of patients following ARM repair. Risk factors for prolapse include male sex, complex ARM type, and sacral abnormalities. Further research investigating the indications for operative management of prolapse and operative techniques for prolapse repair are needed to define optimal treatment. TYPE OF STUDY: Retrospective cohort study. LEVEL OF EVIDENCE: II.

Three-dimensional pelvic ultrasound is a practical tool for the assessment of anal fistula.

OBJECTIVE: This study aims to investigate the diagnostic value of three-dimensional pelvic ultrasound in the preoperative assessment of anal fistula compared with findings of MRI and surgery. METHODS: A total of 67 patients (62 males) with suspected anal fistula were analyzed retrospectively. Preoperative three-dimensional pelvic ultrasound and magnetic resonance imaging were performed in all patients. The number of internal openings and the type of fistula were recorded. The accuracy of three-dimensional pelvic ultrasound was determined by comparing these parameters with surgical outcomes. RESULTS: At surgery, 5 (6%) were extrasphincteric, 10 (12%) were suprasphincteric, 11 (14%) were intersphincteric, and 55 (68%) were transsphincteric. There was no significant difference in the accuracy of pelvic 3D US and MRI, based on internal openings (97.92%, 94.79%), anal fistulas (97.01%, 94.03%), and those under Parks classification (97.53%, 93.83%). CONCLUSION: Three-dimensional pelvic ultrasound is a reproducible and accurate method for determining the type of fistula and detecting internal openings and anal fistulas.

Surgical Simulation of Posterior Sagittal Anorectoplasty for Rectovestibular Fistula: Low-Cost High-Fidelity Animal-Tissue Model.

PURPOSE: To provide a high-fidelity, animal tissue-based model for the advanced surgical simulation of a Posterior Sagittal Anorectoplasty (PSARP) for rectovestibular fistula in anorectal malformation (ARM). MATERIALS AND METHODS: A chicken cadaver was used to assess the feasibility of simulating a PSARP for rectovestibular fistula in ARM. No modification was required to implement the surgical simulation. RESULTS: A detailed description of the high-fidelity surgical simulation model is provided. The PSARP can be simulated while providing realistic anatomy (e.g. common wall between rectovestibular fistula and vagina), adequate rectal size, location and placement of the rectovestibular fistula, and proximity to the vagina. Haptic conditions of the tissue resemble human tissue and operative conditions as well. DISCUSSION: Concerning the decreased exposure of index cases of pediatric surgical trainees and pediatric surgeons in practice, simulation-based training can provide means to acquire or maintain the necessary skills to perform complex surgical procedures [1-5] Surgical simulation models for ARM are limited. Few low-cost trainers are available with predominant artificial and mostly unrealistic tissue [6-8] Animal models have the advantage of realistic multilayer tissue haptic feedback [6]. CONCLUSION: We provide a low-cost, high-fidelity model for correcting a rectovestibular fistula in a child with ARM, a complex operative procedure with low incidence but high-stake outcomes. The described tissue model utilizing the chicken cloaca anatomy provides a high-fidelity model for operative correction of rectovestibular ARM. For simulation purposes in the treatment of ARM, this model appears to be promising in terms of providing realistic pathology and haptic feedback in pediatric dimensions. LEVEL OF EVIDENCE: V.

[Rectourethral fistula treatment using the modified York Mason technique: Failure factors assessment]. / Cure de fistule recto-urétrale par la technique modifiée de York Mason : évaluation des facteurs d'échec.

OBJECTIVES: To assess surgical outcomes and failure factors in the management of rectourethral fistulas treated surgically with the modified York Mason technique based on our center's 25 years of experience. METHODS: From 1997 to 2021, in a single center study, a total of 35 consecutive patients, underwent rectourethral fistula cure, using the modified York Mason technique. Preoperative patient data, surgical outcomes and failure factors were assessed. RESULTS: Of the 35 patients, 28 were successfully managed without the need of further intervention (80%). Median age was 67 years (IQR 62-72) and median follow-up time was 71 months (IQR 30-123). There was no significant difference between the patients that had recurrence or not after the first York Mason. CONCLUSIONS: The modified York Mason technique offers a high success rate for the cure of iatrogenic rectourethral fistulas. No predictive factor of failure, after a first cure of recto-uretral fistula by modified York-Mason technique was reported. LEVEL OF EVIDENCE: 3.

Health Care Costs and Resource Utilization Among Patients With Crohn's Disease With and Without Perianal Fistula.

BACKGROUND: Perianal fistula (PAF), a complication of Crohn's disease (CD), is associated with substantial economic costs and poor prognosis. We determined prevalence of PAF CD in the United States and compared costs and health care resource utilization (HRU) of PAF CD patients with matched non-PAF CD patients. METHODS: This was a retrospective cohort study of claims data from the IBM MarketScan Commercial Database from October 1, 2015, to September 30, 2018. Eligible patients were aged 18 to 89 years with ≥2 CD diagnoses. Patients with PAF CD had ≥1 PAF diagnosis or procedure code and were matched with non-PAF CD patients. Cumulative prevalence of PAF CD in the US population was calculated across total patients in MarketScan. All-cause and gastrointestinal (GI)-related costs and HRU were compared between groups using a generalized linear model (GLM). RESULTS: Cumulative 3-year prevalence of PAF was 7.70% of patients with CD (N = 81,862) and 0.01% of the US population. Among PAF CD (n = 1218) and matched non-PAF CD (n = 4095) patients, most all-cause costs and HRU were GI-related. Mean total all-cause and GI-related health care costs per patient and per year for PAF CD were $85,233 and $71,612, respectively, vs $40,526 and $29,458 for non-PAF CD (P < .0001). Among PAF CD vs non-PAF CD patients, GLM-adjusted proportions of patients with GI-related inpatient, outpatient, or pharmacy visits, mean GI-related inpatient length of stay, and mean GI-related surgeries were higher (P < .0001 for all comparisons). CONCLUSIONS: Costs and HRU are significantly higher for patients with PAF CD vs non-PAF CD patients, highlighting the economic burden of the disease.

Direct health care costs of managing perianal Crohn's Disease in a population based cohort.

BACKGROUND: Crohn's disease is a chronic condition that places a high health care cost burden. Perianal Crohn's disease (pCD) is a difficult phenotype to treat due to poorer response to medical and surgical therapies. No study has assessed if this translates to higher healthcare costs. The aim is to assess the cost of treating pCD and compare to the cost of non-perianal Crohn's disease (CD). METHODS: This is a retrospective case-control cohort study in a population-based setting. The direct healthcare costs for patients with pCD were calculated over 12 months. Data was compared to the control group of non-perianal CD patients on biologic treatment, with the use of the Mann-Whitney rank test to assess significance. RESULTS: 187 Crohn's patients were included (39 pCD, 148 CD). Per patient, annual cost was €17,779.19 and €17,576.86 respectively (p = .9391). Medications were responsible for the majority of cost at 78% and 92% of total cost in pCD and CD, respectively (€13,886.04 in pCD, and €16,007.10 in CD), of which biologics were the main driver. Surgical costs were higher in the pCD group due to a higher cost of luminal surgery (€2633.88 in pCD vs €209.79 in CD, p = .0270). CONCLUSION: This is the first study to assess the cost of treating perianal Crohn's disease in a real-world population. Although the costs were similar overall to non-perianal Crohn's patients, the perianal cohort had higher surgical costs from luminal surgery. This demonstrates the potential to apply early intensive treatment to reduce future surgical cost.

Crohn's disease is a lifelong disease where high-cost drugs are required to achieve optimal outcomes. There is minimal data regarding the cost of managing perianal fistulising Crohn's disease and whether the clinical complexity of these patients translates to higher healthcare costs. Costs were similar between luminal Crohn's disease patients treated with a biologic and those with perianal disease, though the distribution of costs varied. Knowing this distribution will allow for more effective allocation of resources.

ASSESSMENT OF RECURRENT ANAL FISTULAS TREATMENT WITH PLATELET-RICH PLASMA.

BACKGROUND: Surgical treatment of recurrent anal fistulas can lead to numerous complications, including fecal incontinence. Therefore, sphincter preserving techniques are gaining more popularity. OBJECTIVE: The aim of the study was to assess effectiveness of platelet-rich plasma (PRP) therapy in the patients with recurrent cryptoglandular anal fistulas. METHODS: A cohort of 18 patients with anal fistulas was enrolled into a preliminary and prospective trial. They were divided into two groups consisting of eight and ten patients respectively. PRP was injected locally in all patients, however in the group II it was applied after 7 days drainage of fistulas with polyurethane foam or negative pressure wound therapy. On average, three doses of PRP were administered, but with the opportunity to double the number of applications if it was clinically justified. The patients were evaluated in an out-patient department after fortnight and then in 1, 6, and 12 months following the last PRP application. RESULTS: Anal fistulas were closed in 4 (50%) patients from the group I and in 7 (70%) patients form the group II. Although, the difference between both groups was not statistically significant, PRP therapy should be preceded with fistulous tract drainage in all patients. Summarizing, that successful result was achieved in 11 (60%) patients from the entire group of 18 participants. CONCLUSION: The rate of recurrent cryptoglandular anal fistulas closure reaching 60%, after topical treatment with PRP, exceeds the results of other sphincter-saving methods of treatment. Therefore, it might become a novel method of anal fistulas therapy.

Avaliação do tratamento recorrente de fístulas anais com plasma rico em plaquetas / Assessment of recurrent anal fistulas treatment with platelet-rich plasma

ABSTRACT BACKGROUND: Surgical treatment of recurrent anal fistulas can lead to numerous complications, including fecal incontinence. Therefore, sphincter preserving techniques are gaining more popularity. OBJECTIVE: The aim of the study was to assess effectiveness of platelet-rich plasma (PRP) therapy in the patients with recurrent cryptoglandular anal fistulas. METHODS: A cohort of 18 patients with anal fistulas was enrolled into a preliminary and prospective trial. They were divided into two groups consisting of eight and ten patients respectively. PRP was injected locally in all patients, however in the group II it was applied after 7 days drainage of fistulas with polyurethane foam or negative pressure wound therapy. On average, three doses of PRP were administered, but with the opportunity to double the number of applications if it was clinically justified. The patients were evaluated in an out-patient department after fortnight and then in 1, 6, and 12 months following the last PRP application. RESULTS: Anal fistulas were closed in 4 (50%) patients from the group I and in 7 (70%) patients form the group II. Although, the difference between both groups was not statistically significant, PRP therapy should be preceded with fistulous tract drainage in all patients. Summarizing, that successful result was achieved in 11 (60%) patients from the entire group of 18 participants. CONCLUSION: The rate of recurrent cryptoglandular anal fistulas closure reaching 60%, after topical treatment with PRP, exceeds the results of other sphincter-saving methods of treatment. Therefore, it might become a novel method of anal fistulas therapy.

RESUMO CONTEXTO: O tratamento cirúrgico de fístulas anais recorrentes pode levar a inúmeras complicações, incluindo incontinência fecal. Portanto, as técnicas de preservação do esfíncter estão ganhando mais popularidade. OBJETIVO: O objetivo do estudo foi avaliar a eficácia da terapia de plasma rico em plaquetas (PRP) nos pacientes com fístulas anais criptoglandulares recorrentes. MÉTODOS: Uma coorte de 18 pacientes com fístulas anais foi inscrita em ensaio preliminar e prospectivo. Eles foram divididos em dois grupos compostos por 8 e 10 pacientes, respectivamente. PRP foi injetado localmente em todos os pacientes, porém no grupo II foi aplicado espuma de poliuretano ou terapia de feridas por pressão negativa após 7 dias de drenagem de fístulas. Em média, foram administradas três doses de PRP, mas com a oportunidade de dobrar o número de aplicações se fosse clinicamente justificado. Os pacientes foram avaliados em ambulatório após quinze dias e depois em 1, 6 e 12 meses após a última aplicação do PRP. RESULTADOS: As fístulas anais foram fechadas em 4 (50%) pacientes do grupo I e em 7 (70%) pacientes do grupo II. Embora a diferença entre ambos os grupos não tenha sido estatisticamente significante, a terapia PRP deve ser precedida de drenagem do trato fístulo em todos os pacientes. Resumindo, esse resultado bem-sucedido foi alcançado em 11 (60%) pacientes de todo o grupo de 18 participantes. CONCLUSÃO: A taxa de fechamento recorrente de fístulas anais criptoglandulares chegando a 60%, após tratamento tópico com PRP, excede os resultados de outros métodos de tratamento que preservam o esfíncter. Portanto, pode se tornar um novo método de terapia das fístulas anais.

A systematic review of the quality of reporting of interventions in the surgical treatment of Crohn's anal fistula: an assessment using the TIDiER and Blencowe frameworks.

BACKGROUND: Crohn's anal fistula is a challenging condition, and may require multiple surgical procedures. To replicate successful procedures, these must be adequately reported in the literature. The aim of this study was to review the quality of reporting of components of surgical interventions for Crohn's anal fistula. METHODS: A systematic review was conducted. It was registered with PROSPERO (CRD:42019135157). The Medline and EMBASE databases were searched for studies reporting interventions intended to close fistula in patients with Crohn's disease, published between 1999 and August 2019. Abstracts and full texts were screened for inclusion by two reviewers. Dual extraction of data was performed to compare reporting to the TIDiER and Blencowe frameworks for reporting of interventions. RESULTS: Initial searches identified 207 unique studies; 38 full texts were screened for inclusion and 33 were included. The most common study design was retrospective cohort (17/33), and the most frequently reported interventions were anal fistula plug (n = 8) and fibrin glue (n = 6). No studies showed coverage of all domains of TIDieR. Reporting was poor among domains related to who provided an intervention, where it was provided, and how it was tailored. Reporting of domains in the Blencowe framework was poor; the majority of studies did not report the component steps of procedures or efforts to standardise them. CONCLUSIONS: This study demonstrates that reporting on technical aspects of interventions for Crohn's anal fistula is poor. Surgeons should aim to improve reporting to allow accurate reproduction of techniques both in clinical practice and in clinical trials.

A Multicenter Randomized Controlled Trial Comparing Safety, Efficacy, and Cost-effectiveness of the Surgisis Anal Fistula Plug Versus Surgeon's Preference for Transsphincteric Fistula-in-Ano: The FIAT Trial.

OBJECTIVE: To undertake a randomized comparison of the Biodesign Surgisis anal fistula plug against surgeon's preference in treating cryptoglandular transsphincteric fistula-in-ano. SUMMARY BACKGROUND DATA: The efficacy of the Biodesign Surgisis anal fistula plug in healing anal fistulae is uncertain. METHODS: Participants were randomized to the fistula plug with surgeon's preference (advancement flap, cutting seton, fistulotomy, Ligation of the Intersphincteric Fistula Tract procedure). The primary outcome was faecal incontinence quality of life (FIQoL) at 12-months. Secondary outcomes were fistula healing, incontinence rates, and complication and reintervention rates. RESULTS: Between May 2011 and March 2016, 304 participants were randomized to fistula plug or surgeon's preference. No differences were seen in FIQoL between the 2 groups at 12 months. Clinical fistula healing was reported in 66/122 (54%) of the fistula plug and 66/119 (55%) of the surgeon's preference groups at 12 months. Fecal incontinence rates improved marginally in both the groups. Complications and reinterventions were frequent, with significantly more complications in the fistula plug group at 6-weeks (49/142, 35% vs 25/137, 18%; P=0.002). The mean total costs were £2738 (s.d. £1151) for the fistula plug and £2308 (s.d. £1228) for the surgeon's preference group (mean difference +£430, P=0.0174). The average total quality adjusted life years (QALYs) gained was marginally higher in the fistula plug group. The fistula plug was 35% to 45% likely to be cost-effective across a willingness to pay threshold of £20,000 to £30,000 / QALY. CONCLUSIONS: The Biodesign Surgisis anal fistula plug is associated with similar FIQoL and healing rates to surgeon's preference at 12 months. Higher costs and highly uncertain gains in QALYs mean that the fistula plug may not be considered as a cost-effective treatment in the UK NHS.

Burden of disease and adaptation to life in patients with Crohn's perianal fistula: a qualitative exploration.

BACKGROUND: Perianal fistulas are a challenging manifestation of Crohn's disease. Best medical and surgical therapy results in only about a third of patients remaining in remission at one year on maintenance treatment and sustained healing is often elusive. There is little published data on patient perspective of living with the condition or coping strategies in the face of non-curative/non-definitive treatment. We aimed to understand the experience of living with perianal fistula(s) and their impact on quality of life and routine functioning. METHODS: This exploratory qualitative study used purposive sampling to recruit participants with current / previous diagnosis of Crohn's anal fistulas, from national IBD / bowel disease charities. The "standards for reporting qualitative research" (SRQR) recommendations were followed. Unstructured individual face-to-face interviews were audio recorded, transcribed and analysed thematically. Early themes were reviewed by the study team including patient advocates, clinicians and qualitative researchers. RESULTS: Twelve interviews were conducted, achieving apparent data saturation. Three broad themes were uncovered: Burden of symptoms; Burden of treatment; and Impact on emotional, physical and social well-being. Each included several sub-themes, with considerable interplay between these. The impact of perianal fistula(s) on patients with CD is intense and wide reaching, negatively affecting intimate, close and social relationships. Fistulas cause losses in life and work-related opportunities, and treatments can be difficult to tolerate. CONCLUSION: Crohn's perianal fistulas exert a heavy negative physical and emotional impact on patients. These findings will inform development of a patient reported outcome measure to assess treatment effectiveness and quality of life for patients living with this challenging condition.

Rectal advancement flaps for the treatment of transphincteric perianal fistulas: a three-dimensional endoanal ultrasound and quality of life assessment.

This study quantifies the damage to the internal anal sphincter (IAS) after a rectal mucosal advancement flap for a high transphincteric fistula in 16 patients using 3D-endoanal ultrasound. This was correlated with postoperative incontinence and quality of life scores. The median length of involved IAS preoperatively was 50 % (20-100) and 93.72 % for EAS (47.4-100 %). IAS division did not influence continence (p > 0.05). Continence deteriorated between the pre-, postoperative (p = 0.014) and six-month follow-up (p = 0.005), with no significant differences after one year (p > 0.05). The FIQOL score and SF-36 deteriorated initially, with recovery in all domains except for mental health after one year. Three fistulas recurred (18.75 %).

Determinar la precisión diagnóstica de la ecografía tridimensional en casos de fístula perianal en comparación con los hallazgos intraoperatorios durante el procedimiento quirúrgico / Assessment of accuracy of three dimensional endo-anal ultrasound in diagnosis of perianal fistula in comparison to operative findings

Aim : To determine the diagnostic accuracy of three dimensional ultrasound in cases of perianal fistula compared to intra-operative findings during surgical procedure. Background: Perianal fistulae can be either low type (simple) or high type (complex) and surgical treatment options differ accordingly. Preoperative three-dimensional endoanal ultrasonography (3D-EAUS) is a promising diagnostic technique that can effectively assist in choosing the most suitable treatment option for patients with anal fistula by providing the surgeon with accurate outlining of the fistula. Methods: The study is a cross sectional comparative study conducted at Al-Sadr Medical City during the period from September 2018 through September 2019, and included cases with fistula in ano, which were subjected to 3-D ultrasound, then followed up during surgery to obtain the intra-operative findings of the fistula. Results: The study included (78) patients whom their age ranged from (18-65) years. Majority of cases were males (79.49%). For assessing the concordance between 3D-EAUS and the intraoperative findings the Kappa coefficient for the internal opening was 0.9825 (P-value < 0.001), for the external opening was 0.9853 (P-value < 0.00), For the course of primary tract, Kappa = 0.9754 (P-value < 0.001) and for the course of the extension tract was 0.9761 with a P-value of < 0.001. Conclusions: Three-dimensional endoanal ultrasound is an effective and dependable tool for delineation the course of a perianal fistula.

Complex perianal fistulas in Crohn's disease: An anti-TNF α based medico-surgical treatment with magnetic imaging assessment.

BACKGROUND: Anti-TNFα associated to seton drainage has a central role in the treatment of complex perineal Crohn's fistulas (PAF). A precise treatment protocol is lacking. AIMS: to evaluate the results of this combined treatment and identify predictive factors of response. METHODS: It was a retrospective study which included all patients with complex PAF treated with Anti-TNFα. RESULTS: We included 49 patients, mean age of 31.6 years. 17 patients had an active rectal involvement. 35 patients had azathioprin. After the induction, 43 patients had a clinical response. Maintenance therapy was started in 45 cases. After a median of 19 months of Anti-TNFα, 24 patients had a clinical remission (with radiological remission in 20), 17 a partial clinical response, and 4 were in failure. After clinico-radiologic remission setons were removed in all patients, 46% of patients who stopped Anti-TNFα treatment after clinico-radiologic remission relapsed. Absence of rectal involvement and Clinical remission after induction were the independent predictive factors of achieving a clinical remission under maintenance therapy with Anti-TNFα (p=0.016) and clinico-radiological remission (p=0.028). CONCLUSION: An Anti-TNFα based treatment combined with long term loose seton drainage have contributed to the high rates of both clinical and radiological responses in this study. Obtaining a "deep" clinico-radiological remission should be the target of the treatment. Stopping the Anti-TNFα should be avoided even after obtaining such response.