JC FISTULA IN ANO.pptx management and clinical features

Fistula in ano

1. DEPARTMENT OF GENERAL SURGERY JOURNAL CLUB 22/1/2024 PRESENTOR : DR JAGRUTHI R S CHAIRPERSON : DR SUSHIL KUMAR BV ( PROF & HEAD OF DEPARTMENT) MODERATOR : DR KARTHIK

2. FISTULA IN ANO Fistula in ano results from persistent communication between the anal canal (internal opening) and perianal skin (external opening) following spontaneous or surgical drainage of a perianal abscess . Patient’s often report a cyclical pattern of pain and swelling , followed by drainage associated with relief of the symptoms . Physical examination usually identifies one or more external openings with or without granulation tissue . Multiple external openings with or so called “watering can perineum” should trigger suspicion of perianal Crohn disease. Occasionally , the external opening may be subtle or located at a considerable distance from the anus . Careful inspection of the perianal region with gentle palpation searching for a cord like structure can help to identify the course of the fistula track.

3. Classification of Fistula in ano : PARKS CLASSIFICATION : Intersphincteric Transsphincteric Suprasphincteric Extrasphincteric

4. GOALS FOR TREATMENT OF AN ANAL FISTULA: Eliminate the septic focus Remove or ablate epithelized tracts Avoid or minimize the risk of fecal incontinence Prevent recurrence

5. GOODSALL RULE : Fistulas with an external opening anterior to the anus typically track in a radial fashion directly into the anal canal , except for those located at a distance greater than 3 cm from the anal verge , this usually indicates an anterior extension of a horseshoe fistula originating posteriorly . Fistulas with an external opening posterior to the anus often track in a curvilinear fashion to a posterior midline internal opening .

6. SURGICAL APPROACH TO FISTULA IN ANO The modern surgical approach to anal fistulas includes several sphincter-saving procedures, which offer an attempt at cure whilst minimising morbidity, especially the impact on continence. Coloproctologists now have an armamentarium of options, which includes the closure of the fistula tract with plugs, fibrin glue, or collagen paste without fistulotomy ( ie , laying open) or by means of fistulectomy ( ie , core-out technique). Further sphincter-saving options include advancement flaps, 1  LIFT (ligation of the intersphincteric fistula tract), 2  VAAFT (video-assisted anal fistula treatment) 3 laser ablation procedures. 4  Varying success rates and lack of long-term data mean that there is no one universally agreed gold standard and thus treatments are assessed by a combination of patient and surgeon factors

7. FiLaC PROCEDURE Fistula laser closure ( FiLaC ) is a relatively new sphincter-sparing technique in fistula surgery that was initially reported in 2011. It involves the radial dissipation of laser energy in the fistula tract and, through a combination of coagulation and shrinkage of the tract, is proposed to result in progressive sealing of fistulas. Early studies have suggested minimal impact on continence and touted the advantage of minimal morbidity with potential of repeat procedures if the technique fails initially. 

8. LIFT PROCEDURE The novel modified approach through the intersphincteric plane for the treatment of fistula-in- ano , known as LIFT (ligation of inter sphincteric fistula tract) procedure LIFT procedure is based on secure closure of the internal opening and removal of infected cryptoglandular tissue through the intersphincteric approach. Essential steps of the procedure include, incision at the intersphincteric groove, identification of the intersphincteric tract, ligation of intersphincteric tract close to the internal opening and removal of intersphincteric tract, scraping out all granulation tissue in the rest of the fistulous tract, and suturing of the defect at the external sphincter muscle.

9. INTRODUCTION Anorectal fistulas are a common problem, presenting mostly in patients around 40 years old with a wide interquartile range of 20–60 years [1]. In Europe, the incidence of anorectal fistulas varies from 1.04 to 2.32 per 10.000 per year [2, 3], affecting men more often than women (2:1) [3]. Anorectal fistulas are classified based on the extent of involvement of the external and/or internal sphincter in the fistula tract.

10. The Parks classification categorizes fistulas as intersphincteric , transsphincteric , suprasphincteric or extrasphincteric (Parks 1–4), or alternatively, fistulas can be classified as high or low. Intersphincteric and transsphincteric fistulas, in which less than one-third of the external sphincter is involved, are often considered as low, while other variations are regarded as high [4, 5]. The majority of anorectal fistulas are cryptoglandular in origin [6]. Another cause of anorectal fistula is Crohn’s disease, which is associated with complex fistula formation and chronic inflammation, demanding comprehensive multidisciplinary medical and surgical management [7, 8]

11. The classification of anorectal fistulas as ‘high or low’ is an important factor when considering the best type of treatment. Many current treatment options are associated with a high recurrence rate, persistence of complaints or complications. The ultimate goal of treatment is to eradicate the fistula tract and achieve primary healing without recurrent disease and without loss of continence [1]. A seton is often used prior to definitive treatment in order to facilitate the discharge of pus and to allow the inflamed fistula tract to abate before final treatment [9]. Fistulotomy is the preferred treatment for low fistulas, due to the high healing and low recurrence rate. For high fistulas, and those related to Crohn’s disease, the risk of incontinence is increased and sphincter-sparing techniques are preferred.

12. The treatment options for fistulas not caused by Crohn’s disease vary from fibrin glue, a fistula plug, the mucosal advancement flap procedure (MAF) or more recently, the ligation of intersphincteric fistula tract-procedure (LIFT), video-assisted anal fistula treatment (VAAFT), or the fistula-tract laser closure ( FiLaC ™) method [10, 11]. Currently, no treatment is unanimously considered to be superior and opinions vary internationally. According to proctology guidelines developed by the Dutch Society for Surgery, MAF or LIFT are the preferred closure techniques for high anorectal fistulas, dependent on the type of fistula [12].

13. To date, seven studies have researched the effectiveness of the FiLaC ™ procedure, all of which were single-center, retrospective, non-comparative studies [13]. With the current retrospective, multicenter, comparative cohort study, we intend to further expand the literature on FiLaC ™ and to compare it to the current standard closure techniques in the Netherlands.

14. MATERIALS & METHODS PATIENTS : This retrospective study evaluated patients treated for a cryptoglandular anorectal fistula between September 2015 and July 2020. Three Dutch hospitals participated: Flevoziekenhuis (FZ) Almere, Albert Schweitzer Hospital (ASZ) Dordrecht, and MC Zuiderzee (MCZ) Lelystad . INCLUSION CRITERIA : All patients with a high anorectal fistula were retrospectively included after providing written informed consent . EXCLUSION CRITERIA : Patients with a low or extrasphincteric fistula, those with multiple fistulas, Crohn’s disease or patients with missing data regarding healing or recurrence status were excluded

15. Patients were seen in the outpatient clinic prior to treatment to evaluate and grade the fistula. Preoperative magnetic resonance imaging (MRI) was performed in the majority of cases (80%). Inspection under anesthesia was performed to determine if a seton was necessary before definitive surgery, or if a fistulotomy could be performed. After placement of a seton, sphincter-sparing treatment was performed after a period of approximately 6–8 weeks. The type of treatment was chosen after shared decision-making with the patient and was subject to the attending surgeon’s experience and preference, as well as characteristics of the fistula

16. All patients from the three centers followed the same (advised) follow-up schedule: 2 weeks, 6 weeks, 3 months and 6 months. From the MCZ, only FiLaC ™ patients were included. In October 2018, the MCZ was declared bankrupt, causing patient files to become inaccessible after March 2019. It was, therefore, not possible to obtain additional information after this date, unless patients continued their follow-up at one of the other participating centers, which was the case for 35 of the 61 patients (57%).

17. Primary and recurrent fistulas with a cryptoglandular etiology were included in the study. Primary treatment was described as the first sphincter-sparing treatment a patient had undergone in one of the participating centers during the study period. Fistula treatment prior to that period was noted as a fistula treatment in the surgical history. Treatment performed after the primary treatment was noted as secondary treatment. Patients with incomplete data were only included in the study when the primary study parameters (primary healing time and recurrence status) were known.

18. FiLaC ™ was performed under general anesthesia in lithotomy position. The external opening was superficially excised after removal of the seton. The fistula tract was cleaned with a sharp spoon of strip or gauze and rinsed with saline, after which the fiber was introduced with the tip visible at the level of the internal opening. Standard setting of the laser probe was 13 W with a continuous emittance of laser energy. Coagulation of the internal opening and the fistula tract was typically performed with 2–3 s per cm. The internal opening was additionally closed with an absorbable suture. MAF and LIFT were also both performed under general anesthesia in lithotomy position. For both techniques, the external opening was superficially excised after removal of the seton and the fistula tract was cleaned, rinsed with a sharp spoon or strip of gauze and saline. The fistula tract was sometimes excised up to the sphincter. For MAF, the internal opening was excised and a mucosal advancement flap was created by diathermy and sutured over the internal opening with absorbable sutures. For LIFT, the fistula tract was approached through a separate intersphincteric incision and ligated with absorbable sutures. Follow-up data were collected by the attending physician during routine follow-up in the outpatient clinic. In addition, demographics such as age, gender and fistula characteristics such as the Parks classification and the length and location of the fistula, were obtained retrospectively from the electronic patient files. The length and location of the fistula tract was reported by radiologists in the MRI-reports and reflects the distance of the entire tract of the fistula from the mucosal defect to the perianal skin, as seen most often coronal images. Medical history of prior fistula treatments was collected, as well as the use and duration of a seton.

19. Primary outcomes were the clinical primary and secondary healing rates and recurrent disease. Primary healing was defined as a closed external opening without fluid discharge within 6 months of treatment on examination. Persistent disease was defined as no closure of the fistula after 6 months. Recurrence was defined as a recurrent fistula with an external opening and fluid discharge after the fistula and external wound had been closed for a certain period of time. Secondary healing was defined as a closed external opening without fluid discharge after a secondary treatment, independent of the type of secondary procedure. Secondary outcomes were time until healing measured in days, defined as the time until a fistula was clinically healed without fluid discharge and/or complaints. The institutional research board of Flevoziekenhuis approved this multicenter retrospective study on the 9th May 2020. All eligible patients were sent an information letter informing them of the study with the option to opt out. No patients made use of this possibility

20. STATISTICAL ANALYSIS Data were analyzed using SPSS (IBM SPSS Statistics v27). A p-value of 0.05 (two-sided) or lower was considered as statistically significant. Comparisons between the two interventions were made using an independent t-test or a Chi2 -test/ Fisher’s exact test. Differences in continuous, not normally distributed variables were tested with the Mann–Whitney U test. If necessary, post hoc analysis with a Bonferroni correction was performed. Logistic regression was used to analyze correlations. Before running binomial regressions, the linearity of the continuous variables with respect to the logit of the variable was tested via the Box–Tidwell procedure with a Bonferroni correction for the number of variables. If multiple significant univariate values were found, multivariate regression analysis was performed for covariates with a statistical significance of p< 0.1 during univariate analysis.

21. RESULTS This study included a total of 192 patients treated in the participating hospitals within the 5-year study period. A total of 30 patients were excluded, 5 with extra sphincteric fistulas, 2 with multiple fistulas, 5 due to Crohn’s disease and 18 with an unknown primary healing status. This resulted in 162 patients eligible for enrollment. Of these patients, 99 were treated with FiLaC ™ and 63 with standard surgical closing techniques (43 MAF and 20 LIFT). No significant differences in baseline characteristics were found (Table 1). Median follow-up duration was 7.1 months (IQR 4.1–14.4 months) in the FiLaC ™ group versus 6 months (IQR 3.5–8.1 months) days in the control group.

22. There were no significant differences between FiLaC and MAF/LIFT in terms of primary healing (55.6% versus 58.7%, p = 0.601), secondary healing (70.0% versus 69.2%, p=0.950) or recurrence rate (49.5% versus 54%, p=0.420), respectively (Table 2). The median duration of clinical healing was 62 days (IQR 41–88) in the FiLaC ™ group versus 60 days (IQR 35–110) in the MAF/LIFT group (p=0.954).

23. Both the Parks classification and fistula length had a statistically significant influence on the primary healing rate. For every increase in Parks classification, the odds ratio for primary healing decreased by 0.510 (95% CI 0.299–0.871, p=0.014). For every centimeter increase in fistula length, the odds ratio for primary healing decreased by 0.831 (95% CI 0.701–0.985, p=0.033). The recurrence rate was also statistically significantly influenced by the Parks classification and fistula length; for every increase in Parks classification, the odds ratio for recurrence increases by 1.821 (95% CI 1.151–2.879, p=0.010), and for every centimeter increase in fistula length, the odds ratio for recurrent disease increases by 1.261 (95% CI 1.058–1.504, p=0.010).

24. Secondary treatments included excision/fistulotomy, FiLaC ™, MAF and LIFT procedures, in which fistulotomy was used in 50–60% of times for both the FiLaC ™ and MAF/LIFT groups, respectively (see Table 3). Recurrent fistulas treated with a fistulotomy after FiLaC ™ or standard practice showed good healing rates, 100% versus 93.3%, respectively. No single variable had an influence on the secondary healing rate. Although not significant, the use of a seton showed a trend towards positive primary healing and low recurrence rates (further regression analysis details reported in “Appendix”)

25. DISCUSSIONS In this retrospective multicenter comparative cohort study, results indicate that the FiLaC ™ method might not be inferior to current standard surgical closure techniques. To the best of our knowledge, this is the first comparative study of the FiLaC ™ method compared to other standard closure techniques and may, therefore, provide an interesting base for future studies investigating this relatively novel technique

26. The clinical healing rates for fistula closure techniques are limited and, although treatment is extensively investigated, modern medicine has still not found one technique with a higher closure rate than approximately 60–70% [10, 13]. Considering the challenge to find a suitable and effective technique, various procedures have been developed in an attempt to increase the healing and closure rates. FiLaC ™ is a relatively modern approach and a few studies have investigated its ability to achieve similar, or improved, results. One recent retrospective cohort study of 67 patients revealed a primary healing rate of 59.7%, while recent systematic review of seven single-center FiLaC ™ studies showed an average primary healing rate of 63%, with 2 comparative FiLaC ™ studies achieving 64% and 40% primary healing rates [13–16]

27. When comparing our results to these studies, the primary healing rate was 55.6% in the FiLaC ™ group, which was lower than the pooled primary healing rate in the systematic review by Frountzas et al. (63%) [16], but significantly higher than another cohort study of only 20 patients with a healing rate of 20% [17]. This study used a different type of laser probe, potentially explaining the difference in results. Frountzas et al. also found an overall complication rate of 8%, but unfortunately, incontinence rates were not mentioned separately, and were instead, included in this 8% with a follow-up period of 6–30 months. The mean follow-up time for the eight included studies was 19 months. Compared to similarly sized FiLaC ™ studies by Wilhelm et al. (64%) and Terzi et al. (40%), our results are roughly in the middle [14, 15]. However, both of these studies had a significantly longer follow-up period with an average duration of 24 and 28 months, respectively. Wilhelm et al. further reported their secondary healing rate as the combined healing rate after a primary and/or secondary treatment, with a secondary healing rate of 88% [14]. If the current study also reported the secondary healing rate as a combined healing rate, then this would be 89.0%, very similar to that reported by Wilhelm et al. [14]

28. To date, only 2 studies have investigated the FiLaC ™ method with more than 100 patients. Both were non-comparative studies [14, 15]. Our study included 99 fistulas treated with the FiLaC ™ method and is the first comparative study. While Wilhelm et al. and Terzi et al. both had longer median follow-up periods, Terzi et al. had the second follow-up visit always in 2016, regardless of when patients were operated on from 2012 onwards. This causes heterogeneity in follow-up periods between the patients as some were very short and others very long. This could have resulted in an inflated follow-up period, making it less reliable for comparison. The follow-up period of the present study was shorter, which could be due to several factors. Data were collected retrospectively and thus properly pre-determined follow-up moments in the context of research were not performed, despite routine follow-up usually being performed after 2 weeks, 6 weeks, 3 months and 6 months. The bankruptcy of the MCZ hospital further limited follow-up data, although a large proportion of cases continued follow-up in the other participating hospitals

29. Concerning recurrent fistulas, it seems that after a first sphincter-sparing treatment most high fistulas “downgrade” to a lower or blind ending fistula, which makes fistulotomy in the second instance possible. This of course has a better healing rate of around 95% [9, 10]. Although these results seem promising, the quality of the data and number of patients is limited and the data on continence are lacking. We found that there was a correlation between the severity of a fistula, both Parks classification and fistula length, and the rate of primary healing and recurrences, where fistulas with a more complex classification had lower chances of primary healing and greater chances of recurrence. GarciaAguilar et al. also found the severity of the fistula, classifed according to Parks, to have a negative influence on the recurrence rate [18], while Lauretta et al. also concluded that the length of a fistula had a significant effect on the healing rate when treating with FiLaC ™, with shorter fistulas showing better results [19]. However, it is possible that there is high inter-physician variation when determining fistula length considering its complexity, and this should be taken into consideration when interpreting these results.

30. This study has several limitations. One is the limited follow-up period, while the retrospective design and data collection were restrictive. Another limitation is the fact that postoperative incontinence rates were not specifically recorded. The systematic review on the MAF and LIFT procedure by Stellingwerff et al. showed pooled incontinence rates of 7.8% (CI 3.3–12.4) for the MAF procedure and 1.6% (CI 0.4–2.8) for the LIFT procedure, which was significantly different [20]. Due to limited samples, these results are of cryptoglandular and Crohn’s fistulae together. For the two similarly sized studies investigating the FiLaC ™ method, Wilhelm et al. and Terzi et al. reported no cases of incontinence, but those studies did not use formal incontinence scores for their assessment [14, 15]. In our study, we also did not fnd any cases of incontinence after FiLaC ™, but again, no formal scoring systems were used. Incontinence is not expected when using the FiLaC ™ method, as the energy of the laser does not destroy the sphincter but only the fistula tract. However, Stijns et al. described a negative alteration in the fecal incontinence severity index in 7 patients (39%) after laser treatment [17]. These confecting results further warrant future research on this important topic. Future investigations regarding the FiLaC ™ method should also consider the surgical learning curve and seemingly low complication rates

31. As well as the incontinence rate, this study did not report on quality of life or on fistula closure confirmed with MRI which would provide an interesting nuance compared to only clinical closure. Future research would benefit from a core outcome set, which is currently under development, to increase the consistency and quality of future studies [21]. Finally, the MAF and LIFT are two different procedures, so compiling them together as one control group could affect the interpretation of our results. However, both treatments are used in the case of high and/or complex perianal fistulas as stated by the Dutch proctology guidelines [12]. Furthermore, both procedures are used to treat the types of fistulas that could also be treated with the FiLaC ™ method

32. CONCLUSIONS In this retrospective comparative study, FiLaC ™ treatment of high anorectal fistulas does not appear to be inferior to MAF or LIFT with regard to clinical healing or recurrence rates. The results of this study suggest FiLaC ™ to be a suitable treatment alternative for high cryptoglandular fistulas compared to standard surgical closure techniques. Prospective studies with a longer follow-up period and well-determined postoperative parameters such as complication rates, MRI closure, incontinence, and quality of life are warranted.

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