Fistulae-in-ano remain a major problem for the colorectal surgeon. Whilst they do not threaten life they are a major cause of morbidity. Low fistulae (inter-sphincteric and low trans-sphincteric) can be treated with simple fistulotomy with a high cure rate and minimal effect on sphincter function. The problem arises when the fistula tract is higher and fistulotomy is not an option without risk of compromise to ano-rectal function. This has led to a variety of measures for the treatment of such fistulae, all of which try to eradicate the sepsis and fistula tract but preserving as much external sphincter as possible. Options which have been used include setons (tight and loose), re-routing of the fistula tract, fibrin glue, and core fistulectomy with a flap advancement. All these methods have been reviewed recently in a position statement on fistulae in ano (Williams 2007).

A further method has been introduced in recent years and, if successful, offers a chance of cure of the fistula but without division of the external anal sphincter. This new procedure is to use a tapered fibrin plug which is placed into the fistula tract once the acute septic episode has settled. The tapered shape of the plug is to ensure that the plug remains in place, closing the internal opening, and encouraging in-growth of host tissue over 3-6 months. The results from around the world vary greatly with success rates ranging from 13% to 83% and, whilst some failures are clearly due to poor patient selection, it is difficult to comprehend the wide variety that seems to exist.
The plug is comprised of lyophilised porcine intestinal submucosa and once the fistula has been drained with a loose seton the plug is rehydrated and inserted through the tract such that the wider end sits at the internal opening. The internal part is sutured firmly to the internal sphincter whilst the external part is not secured. The external wound is left open to allow free drainage of any fluid. Postoperatively the patient is told to rest for two weeks and to avoid strenuous exercise. In the communication from the original authors (Champagne 2006) full bowel preparation was performed and antibiotic prophylactic cover was with metronidazole. The first communication of this technique was from Atlanta (Johnson 2006) and reported on 25 patients, 10 of whom had fibrin glue closure and 15 the fibrin plug. The results favoured the fibrin plug with only 13% failing compared with 60% of those that were treated with fibrin glue. Although fistulae associated with Crohn’s disease were excluded in this communication a further paper from the same group (O’Connor 2006) reported their experience with the Surgisis fibrin plug in 20 consecutive patients with fistulae complicated Crohn’s disease. They reported success in 80% with a greater chance of successful closure if the tract was single rather than complex with several openings. The final paper from this group (Champagne 2006) gave the results from the use of the fibrin plug in 46 patients. The overall success rate was 83%. Whilst encouraging, others have been unable to match these results and the long term success remains unknown. It is of some concern that this method will not deal with secondary tracts and “healing” of the external opening does not necessarily imply healing of the fistula. It would be interesting to see sequential MR imaging in these patients. Most of the other results using this method are in abstract form and a recent overview of the world literature maintained a healing rate of 55% (Armstrong personal communication). Van Koperman (2007) recently reported the results from two centres and, in 17 patients, 7 healed (41%) with the remaining 10 suffering a recurrence. They make the point that little is lost by attempting to treat the fistula with a fibrin plug. Our own experience has been combined with that of colleagues in Aarhus and was presented in abstract form at the recent meeting of the European Society of Coloproctolgy in Malta. A total of 43 patients have been treated and, to date with short follow-up, the healing rate has been 37% with a further 11% reporting an improvement in symptoms (Thekkinkattil 2007). In conclusion, this new technique shows some promise but there are details of the procedure which, if not followed, may lead to early extrusion of the fibrin plug. The fact that no muscle is divided is clearly an advantage but the true value of this technique over other, more established procedures, will need further experience. Unfortunately there are few randomised trials in the field of fistula surgery but this perhaps is one area that requires either a trial or, at the very least, a comprehensive audit of
experience.

References

• Champagne BJ, O’Connor LM, Ferguson M et al Efficacy of anal fistula plug in closure of cryptoglandular fistulas: long-term follow-up. Dis Colon Rectum 2006; 49:1817-1821
• Johnson EK, Gaw JU, Armstrong DN. Efficacy of anal fistula plug vs. fibrin glue in closure of anorectal fistulas. Dis Colon Rectum 2006; 49: 371-376
• O’Connor L, Champagne BJ, Ferguson MA et al. Efficacy of anal fistula plug in closure of Crohn’s anorectal fistulas. Dis Colon Rectum 2006; 49: 1569-1573
• Williams JG, Farrands PA, Williams AB et al. The treatment of anal fistula: ACPGBI Position Statement. Colorectal Dis. 2007; 9 (Suppl. 4): 18-50
• Van Koperman PJ, D’Hoore A, Wolthuis AM et al. Anal fistula plug for closure of difficult anorectal fistula: a prospective study. Dis Colon Rectum 2007; 50: 2168-2172

Expérience de Saint-Antoine:

Objectif: Le traitement des fistules anales qui ne peuvent être traitées par fistulotomie fait appel à des techniques variées dont les objectifs sont d’éviter la récidive sans créer d’incontinence. Des taux de fermeture de la fistule voisins de 80% ont été rapportés par une technique d’obturation du trajet par une prothèse biodégradable (Surgisis) (1). L’objectif de cette étude était d’évaluer l’efficacité de cette nouvelle technique.
Méthode: L’obturation du trajet fistuleux par une prothèse biodégradable (Surgisis) a été proposée depuis Juin 2006 aux patients ayant une fistule ano-périnéale trans-sphinctérienne haute ou suprasphinctérienne. L’intervention était faite après préparation colique et en dehors de toute infection aiguë. Le trajet fistuleux était rincé et l’ obturateur mis en place par l’orifice primaire endo-anal auquel
il était solidement arrimé par plusieurs points de fils lentement résorbables 2.0 prenant en partie le sphincter interne. L’orifice externe était laissé ouvert. Les patients étaient prévenus d’éviter tout effort pendant 2 semaines. Ils ont été revus à 1 mois, 3 mois et 6 mois. La fermeture du trajet fistuleux, sans écoulement ni abcès était considérée comme un succès.

Résultats: Quinze patients (7 femmes) d’un âge médian de 46 (32-58) ans ont été traités. Trois de ces patients avaient une maladie de Crohn, et trois avaient une fistule ano-vulvaire. Il s’agissait toujours d’une fistule à trajet unique pour laquelle 7 patients avaient eu avant de 1 à 5 interventions. Une patiente avait une colostomie au moment de la mise en place de l’obturateur et tous sauf un avaient eu un séton pendant 5,44±4,31 mois. Trois patients ont expulsé la prothèse à J3, J7et J7 et ont eu à distance une deuxième prothèse, expulsée à nouveau à J7 dans deux cas. Un patient a présenté un abcès au 4ème jour post-opératoire. Le trajet fistuleux était fermé chez 6/15 patients (40%) à 3 mois et , 6/11 (54%) à 6 mois dont la patiente avec une fistule ano-vulvaire dont la colostomie a pu être supprimée avec succès. Un patient sur 3 avec maladie de Crohn a fermé son trajet (33%). Le taux de succès était de 5/8 et de 4/6 à 3 et 6 mois pour les patients n’ayant pas eu de traitement préalable, contre 1/7 et 2/6 pour les autres (ns). La continence a été préservée chez tous les patients.

Conclusion: Le traitement des fistules ano-périnéales par prothèse biodégradable a permis dans cette étude d’obtenir des taux de succès de 40% à 3 mois et de 54% à six mois, dans la moyenne des résultats de la littérature qui varient de moins de 20 à 80%. Cette technique présente l’avantage d’être simple et de ne pas entraîner d’incontinence. L’une de ses limites est le prix de la prothèse(700 €).