Understanding and Treating Supralevator Fistula-in-Ano: MRI Analysis of 51 Cases and a Review of Literature

Transanal opening of the intersphincteric space (TROPIS): a novel procedure on the horizon to effectively manage high complex anal fistulas

Anal fistulas, especially complex and high fistulas, are difficult to manage. The transanal opening of the intersphincteric space (TROPIS) procedure was first described in 2017, and a high success rate of over 90% was reported in high complex fistulas. Since then, more studies and even a meta-analysis have corroborated the high efficacy of this procedure in high fistulas. Conventionally, the main focus was to close the internal (primary) opening for the fistula to heal. However, most complex fistulas have a component of the fistula tract in the intersphincteric plane. This component is like an abscess (sepsis) in a closed space (2 muscle layers). It is a well-known fact that in the presence of sepsis, healing by secondary intention leads to better results than attempting to heal by primary intention. Therefore, TROPIS is the first procedure in which, instead of closing the internal opening, the opening is widened by laying open the fistula tract in the intersphincteric plane so that healing can occur by secondary intention. Although the drainage of high intersphincteric abscesses through the transanal route was described 5 decades ago, the routine utilization of TROPIS for the definitive management of high complex fistulas was first described in 2017. The external anal sphincter (EAS) is completely spared in TROPIS, as the fistula tract on either side of the EAS is managed separately-inner (medial) to the EAS by laying open the intersphincteric space and outer (lateral) to the EAS by curettage or excision.

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.

Comparison of different methods to manage supralevator rectal opening in anal fistulas: A retrospective cohort study

INTRODUCTION

Supralevator fistula-in-ano are difficult to manage. If these fistulas have an additional supralevator internal-opening in rectum apart from the primary internal-opening at the dentate line, then the management becomes even more difficult. There is no literature/guidelines available on the management of supralevator rectal opening (SRO).

METHODS

All consecutive supralevator fistula-in-ano patients having a SRO were retrospectively analyzed. The operative management of SRO in these fistulas was reviewed. All the fistulas were managed by the same procedure, transanal opening of intersphincteric space (TROPIS). The latter was a modification of LIFT (ligation of intersphincteric tract) procedure in which the intersphincteric tract was opened-up in the rectum rather than ligated (as is done in LIFT). The SRO was managed in three ways, group-1:SRO was laid-open into the rectum in continuity with the primary opening at dentate line, group-2:the mucosa around SRO was cauterized, group-3:nothing could be done to SRO.

RESULTS

Out of 836 patients operated between 2015 and 2020, 138 patients (16.5%) had supralevator extension. Amongst these, 23/138 (16.6%) patients had a SRO. 2 patients were excluded (short follow-up) and 21 patients were included in the analysis. 12/13(92%) patients in group-1, 4/5 (80%) patients in group-2 and 2/3(67%) patients in group-3 got healed (p=0.47, Chi-square test). The overall healing rate was 18/21(86%).

CONCLUSIONS

The supralevator rectal opening (SRO) heals well irrespective of the method utilized. Thus, proper management of the primary opening at the dentate line holds the key to fistula healing and SRO is perhaps not much responsible for persistence of the fistula. However, more studies are needed to corroborate these findings.

Extreme horseshoe and circumanal anal fistulas-challenges in diagnosis and management

Objectives:

Extreme horseshoe anal fistulas are rare, and there are little data on the diagnosis and management of these fistulas.

Materials and Methods:

Patients with horseshoe anal fistula, in which the fistula tract encircled more than 75% of the anal circumference were included in the study. All patients were assessed by a preoperative magnetic resonance imaging (MRI). The patients were managed by a sphincter-sparing procedure. The continence was evaluated by an objective continence scoring system (Vaizey's scores).

Results:

1059 anal fistula patients were operated on over 7-years with a median follow-up of 36 months (range: 5–79 months). There were 47/1059 (4.4%) patients with extreme horseshoe anal fistulas. In 4/47 patients, the fistulas were complete circumanal (encircling anal canal completely). The mean age was 39.5 ± 10.9 years, M/F-41/6. The fistula was supralevator in 12/47 (25.5%), had an associated abscess in 28/47 (59.6%), and was recurrent in 33/47 (70.2%) patients. The tracts were intersphincteric in 27/47, transsphincteric in 2/47, and both (intersphincteric and transsphincteric) in 18/47 patients. All patients (n = 47) were managed by a sphincter-sparing procedure. Four patients were lost to follow-up. The fistula healed completely in 34/43 (79%) patients. There was no significant difference between preoperative and postoperative Vaizey's continence scores 0.031 ± 0.17 and 0.033 ± 0.18 respectively (P=0.90, Mann–Whitney U-test).

Conclusion:

Extreme horseshoe fistulas are rare, with an incidence of about 4% (in a referral practice). The missed diagnosis of circumferential tracts could lead to a recurrence. MRI was pivotal to confirm the diagnosis. Proper identification and management of internal opening and adequate drainage of all tracts were crucial for successfully treating extreme horseshoe fistulas.

A New Anatomical Pathway of Spread of Pus/Sepsis in Anal Fistulas Discovered on MRI and Its Clinical Implications

BACKGROUND

In the anal sphincter complex, the intersphincteric space between the internal and external sphincters is the only conventionally recognized pathway for the spread of sepsis. However, there is another unrecognized space discovered on MRI, the "outer-sphincteric space", between the external anal sphincter and its lateral fascia along which pus can spread. An abscess in the intersphincteric space is easily drained into the rectum via the transanal route and is more likely to spread into the supralevator space. Conversely, an abscess in the outer-sphincteric space is difficult to drain transanally into the rectum and is more likely to become a transsphincteric abscess/fistula.

METHODS

The MRIs of anal fistula patients operated over four years on intersphincteric abscesses were analyzed. The pattern of spread into the ischiorectal fossa and/or supralevator space and ease of drainage into the rectum through the transanal route were studied.

RESULTS

Thirty-six patients were operated on to drain their intersphincteric abscesses through the anal canal. Two distinct patterns were noted. Twenty patients had abscesses in the intersphincteric space, which were easily drained into the rectum. Of them, 6/20 had supralevator extension, while only 1/20 had spread to the ischiorectal fossa. In 16/36 patients, the abscess was in the outer-sphincteric space and could not be drained into the rectum. In 9/16 of these patients, pus spread into the ischiorectal fossa but supralevator spread did not happen in any patient.

CONCLUSION

Apart from the intersphincteric space, there is perhaps another unrecognized anatomical space - the outer-sphincteric space - discovered on MRI, through which pus can spread in anal fistulas or abscesses.

The new pathways of spread of anal fistula and the pivotal role of MRI in discovering them

Conventionally, in the pathophysiology of anal fistulas, there is only one space considered significant for the spread of pus in the sphincter complex: the intersphincteric space. However, with increasing experience in the high-resolution MRI, and more focus being given on managing fistulas through the intersphincteric space, two additional pathways of fistula spread have been identified. First is a newly described space labelled as the outer-sphincteric space. Second is a known anatomical space (inner intersphincteric space), but this space was considered as irrelevant from the point of view of fistula spread. The conventional intersphincteric space is present in between these two spaces and is referred as 'middle intersphincteric space' in this paper. These three distinct spaces have significant clinical implications as the pattern of spread of pus is quite different in each space, and the management also differs for fistula tract in each of these spaces.

Current concepts in the pathogenesis of cryptoglandular perianal fistula

Cryptoglandular perianal fistula is a common benign anorectal disorder that is managed mainly with surgery. A fistula is typically defined as a pathological communication between two epithelialized surfaces. More specifically, perianal fistula manifests as an abnormal tract between the anorectal canal and the perianal skin. Perianal fistulas are often characterized by significantly decreased patient quality of life. The cryptoglandular theory of perianal fistulas suggests their development from the proctodeal glands, which originate from the intersphincteric plane and perforate the internal sphincter with their ducts. Involvement of proctodeal glands in the inflammatory process could play a primary role in the formation of cryptoglandular perianal fistula. The objective of this narrative review was to investigate the current knowledge of the pathogenesis of cryptoglandular perianal fistula with the specific aims of characterizing the potential role of proinflammatory factors responsible for the development of chronic inflammation. Further studies are crucial to improve the therapeutic management of cryptoglandular perianal fistulas.

Transanal opening of the intersphincteric space: a novel sphincter-sparing procedure to treat 325 high complex anal fistulas with long-term follow-up

AIM

Sepsis in the intersphincteric plane behaves like an abscess in a closed space and is present in most complex fistulas. Ignoring this sepsis is a cause of recurrence. Complex fistulas can be successfully managed by transanal opening of the intersphincteric space (TROPIS) into the anal canal. The long-term efficacy of the TROPIS procedure was analysed in an exclusive cohort of high complex anal fistulas.

METHODS

All consecutive patients operated for a high complex fistula-in-ano were included prospectively. Preoperative MRI scans were obtained for all the patients. The intersphincteric space and internal opening was laid open into the anal canal while preserving the external sphincter. The external tracts were thoroughly curetted and cleaned. Fistula healing rate and objective incontinence scores (preoperatively and during long-term follow-up) were analysed.

RESULTS

A total of 325 patients (age 39.9 ± 10.9 years, 292 men) were operated with TROPIS and had a follow-up of 7-67 months (median 36 months). In the cohort, 67.4% (219) had recurrent fistulas, 82.8% (269) had multiple tracts, 36.3% (118) had horseshoe tracts, 37.5% (122) had associated abscesses and 24% (78) were supralevator fistulas. Nineteen patients were excluded. Fistulas healed completely in 78.4% (240/306) of patients and did not heal in 21.6% (66/306) of patients. 36/66 of these patients were operated again and the fistulas healed in 28 patients. Thus, the overall healing rate was 87.6% (268/306). The mean preoperative and postoperative incontinence scores were 0.085 ± 0.35 and 0.119 ± 0.48 respectively (P = 0.38). The healing rate of fistulas with associated acute abscesses was similar to the fistulas without abscesses (87% vs. 88%, P = 0.85).

CONCLUSION

Transanal opening of the intersphincteric space is a safe and highly effective sphincter-sparing procedure to manage high complex fistulas-in-ano.

Comparison of different methods to manage supralevator rectal opening in anal fistulas: A retrospective cohort study

INTRODUCTION

Supralevator fistula-in-ano are difficult to manage. If these fistulas have an additional supralevator internal-opening in rectum apart from the primary internal-opening at the dentate line, then the management becomes even more difficult. There is no literature/guidelines available on the management of supralevator rectal opening (SRO).

METHODS

All consecutive supralevator fistula-in-ano patients having a SRO were retrospectively analyzed. The operative management of SRO in these fistulas was reviewed. All the fistulas were managed by the same procedure, transanal opening of intersphincteric space (TROPIS). The latter was a modification of LIFT (ligation of intersphincteric tract) procedure in which the intersphincteric tract was opened-up in the rectum rather than ligated (as is done in LIFT). The SRO was managed in three ways, group-1:SRO was laid-open into the rectum in continuity with the primary opening at dentate line, group-2:the mucosa around SRO was cauterized, group-3:nothing could be done to SRO.

RESULTS

Out of 836 patients operated between 2015 and 2020, 138 patients (16.5%) had supralevator extension. Amongst these, 23/138 (16.6%) patients had a SRO. 2 patients were excluded (short follow-up) and 21 patients were included in the analysis. 12/13(92%) patients in group-1, 4/5 (80%) patients in group-2 and 2/3(67%) patients in group-3 got healed (p=0.47, Chi-square test). The overall healing rate was 18/21(86%).

CONCLUSIONS

The supralevator rectal opening (SRO) heals well irrespective of the method utilized. Thus, proper management of the primary opening at the dentate line holds the key to fistula healing and SRO is perhaps not much responsible for persistence of the fistula. However, more studies are needed to corroborate these findings.

A Simple Protocol to Effectively Manage Anal Fistulas with No Obvious Internal Opening

Purpose

In some anal fistulas, the internal/primary opening cannot be located even after examination and assessment on MRI or transrectal ultrasound. The efficacy of a simple new protocol to manage such therapeutically challenging fistulas was tested.

Patients and Methods

All anal fistula patients operated consecutively over 7 years were included in the study. A simple two-step protocol was followed for fistulas in which the internal opening was not locatable after clinical examination and MRI assessment. First, the MRI was reassessed. The site where the fistula was closest to the internal sphincter was noted. It was assumed that the internal-opening was located at that position and the fistula was treated accordingly. Second, in horseshoe anal fistulas with no apparent internal opening, it was assumed that the internal opening was located in the midline. Low fistulas were treated by fistulotomy and high fistulas by a sphincter-sparing procedure. Incontinence was evaluated by objective incontinence scores (Vaizey scores).

Results

A total of 757 patients were operated (median follow-up-33 months). Of these, 57 patients were excluded due to short or inadequate follow-up. In 154/700 (22%) patients, the internal opening could not be located while in 546/700 (78%), the internal opening was found. Both the groups were similar in all parameters. In the "internal-opening found" group, the fistula healed completely in 486/546 (89%) and in the 'internal-opening not found group', the fistula healed in 140/156 (90.9%) (p=1.01). The objective continence scores did not change significantly after surgery in both the groups.

Conclusion

This new protocol seems effective as a high cure rate could be achieved in 'internal-opening not found' fistulas which was comparable to fistula healing in the 'internal-opening found' group.

Significance and Impact of the Intersphincteric Plane Sepsis in the Management of the Perianal Sepsis: Ultrasound Study

Background The intersphincteric plane (ISP) is a potential space between the external and the internal anal sphincters. About 90% of the perianal sepsis is caused by an obstruction of the ducts of anal glands with subsequent secondary bacterial infection. The imaging modalities used to diagnose perianal sepsis are the ultrasound via endoanal and transperineal routes and magnetic resonance imaging.

Objective  The study aimed to identify the various patterns of the ISP sepsis and their incidence among our study group and to clarify the significance of ISP in the pathogenesis of anorectal abscesses and various types of perianal fistula tracts, to optimize the surgical management.

Methods Retrospective descriptive study in which 57 patients with an ISP sepsis were evaluated with full medical history, clinical exam, and ultrasound; the final diagnosis was based on combining the results of ultrasound, digital rectal examination under anesthesia, and the operative results.

Results The current study showed many patterns of the ISP sepsis and estimated the incidence of each pattern among our study group; such patterns could be fistula tracts, sinus tracts, abscesses, intersphincteric abscess with supralevator extension, sinus with abscess formation, fistula with abscess formation, distension of the ISP with free pus, and other complex patterns like horse abscess, abscess with transsphincteric sinus, and ISP fistula/sinus with transsphincteric branches.

Conclusion Understanding the role of the ISP in the pathogenesis of anorectal abscesses and perianal fistula tracts can help in reaching the optimum way of management.

Management of Complex Cryptoglandular Anal Fistula: Challenges and Solutions

Anal fistulae can be a very difficult disease to manage. The management of complex fistulae is even more challenging. The risk to the fecal continence mechanism due to damage to the anal sphincters and refractoriness to the treatment (high recurrence rate) pose the two biggest challenges in the management of this disease. Apart from these, there are several other challenges in the treatment of complex fistulae. The intriguing and uphill task is that satisfactory solutions to most of these challenges are still not known, and there is hardly any consensus on whatever treatment solutions are available. To summarize, there is no gold-standard treatment available for treating complex anal fistulae, and the search for a satisfactory treatment option is still on. In this review, the endeavor has been to discuss and highlight recent path-breaking updates in the management of complex anal fistulae.

Recurrent anal fistulas: When, why, and how to manage?

Anal fistula is a commonly encountered anal condition in the surgical practice. Despite being a benign condition, anal fistula remains to represent a surgical challenge, particularly the complex type of fistulas. One of the common complications of anal fistula surgery is the persistence or recurrence of the pathology, both defined as failure of surgery. Recurrent anal fistulas after previous surgery represent an even more challenging problem since they are usually associated with a higher risk of re-recurrence and continence disturbance. The present review aimed to shed light on various aspects of recurrent anal fistulas, including the different definitions of failure after surgery, risk factors of recurrence, problems associated with management of recurrent fistulas, and assessment and treatment of recurrent anal fistulas.

Laser ablation of fistula tract (LAFT) and complex fistula-in-ano: "the ideal indication" is becoming clearer…

BACKGROUND

An initial study enabled us to achieve 60% healing of high transsphincteric fistula-in-ano with laser ablation of fistula tract (LAFT) The purpose of this new study was to investigate other predictors of the success of this technique in the treatment of complex anoperineal fistulas.

METHODS

All patients treated with LAFT in our department between May 2017 and October 2018 were included prospectively. LAFT was used for patients with complex anoperineal fistulas who were at high risk of anal incontinence after fistulotomy. The fistula was considered healed when the internal and external openings were closed and the patient experienced no pain or leakage.

RESULTS

A total of 100 consecutive patients (65 males) with a median age of 43 years (range 22-88 years) were included in the study. Eight patients were lost to follow-up. The fistulas were low (8%) or high (79%) transsphincteric, and suprasphincteric (13%). After a median follow-up of 13.6 months (range 6-23 months), fistula healing was observed in 41 patients (44.6%). On univariate analysis, an anterior location, a narrow internal orifice and administration of less than 400 J of energy were significantly associated with healing. On multivariate analysis, a narrow internal orifice and low energy administration remained significant predictive factors of success [OR 5.08 (1.03-25.03), p = 0.046; OR 2.59 (1.08-6.17), p = 0.032]. No new cases of anal incontinence or any worsening of pre-existing anal incontinence was observed during follow up.

CONCLUSIONS

This study indicates that complex anoperineal fistulas with a narrow internal orifice can be successfully treated with less than 400 J and are ideal for LAFT.

The optimal indication for FiLaC® is high trans-sphincteric fistula-in-ano: a prospective cohort of 69 consecutive patients

BACKGROUND

The aim of our study was to prospectively evaluate the effectiveness of the Fistula Laser Closure (FiLaC^®) technique in patients at high risk of anal incontinence and to determine the predictors of success and the impact of the procedure on anal continence.

METHODS

A prospective study was conducted on all patients treated with FiLaC^® in our department in May 2016-April 2017, because they were at high risk of anal incontinence after fistulotomy, The fistula was considered healed when the internal and external openings were closed and the patient experienced was no pain or leakage.

RESULTS

A total of 69 consecutive patients (34 males) with a median age of 40 years (33-53 years) were included in the study. One patient was lost to follow up. The fistulas were intersphincteric (3%), low (15%) or high (66%) trans-sphincteric, and suprasphincteric (16%). After a median follow-up period of 6.3 months (4.2-9.3), fistula healing was observed in 31 patients (45.6%). In univariate analysis, high trans-sphincteric fistulas (p = 0.007) and age over 50 years (p = 0.034) were significantly associated with healing. In multivariate analysis, only high trans-sphincteric fistulas were a predictive factor of significant success. No new cases of anal incontinence or any worsening in case of pre-existing anal incontinence were observed during follow-up.

CONCLUSIONS

FiLaC^® is particularly effective in cases of high trans-sphincteric fistulas (60% cure). This technique seems to be the most promising sphincter-saving technique available for this indication.

Anal fistula and pilonidal sinus disease coexisting simultaneously: An audit in a cohort of 1284 patients

Fistula-in-ano and pilonidal disease are not known to occur together. In a retrospective study, all patients having fistula-pilonidal disease coexisting simultaneously were included. Out of 1284 patients, 933 were operated (fistula-in-ano, 849; pilonidal disease, 77; and coexisting fistula-pilonidal, 7). A total of 351 patients did not undergo any surgery (two patients had coexisting fistula-pilonidal). Thus, a total of nine patients having coexisting fistula-pilonidal sinus were included in the study (mean age 35.8 ± 19.9 years, M/F 7/2). pIn 6/9 patients, the pilonidal tract was communicating with fistula-in-ano, and in 3/9 patients, they were not communicating/connected. The connection could be established preoperatively with the help of MRI. In all patients with communicating fistula-pilonidal sinus (n=6), the fistula was posterior. 6/9 patients had recurrent fistula and all (9/9) had multiple tracts. The fistula was high and complex in 8/9 patients (grade IV-7, grade V-1). 4/9 patients tested positive for tuberculosis while one patient was suffering from hidradenitis suppurativa. The latter improved on medical treatment. One patient did not agree for surgery and seven were operated. The disease healed in four patients, the disease did not heal in one patient, and two patients were in the convalescent stage. Anal fistula and pilonidal disease can coexist in a same patient and can even be connected. Such diseases are more complex and have a higher incidence of associated diseases like tuberculosis. Magnetic resonance imaging plays a pivotal role in diagnosis. If the connection is missed, the disease treatment becomes difficult.