High complex anal fistula managed by the modified transanal opening of the intersphincteric space via the inter-sphincteric approach:A case report

BACKGROUND High complex anal fistulas are epithelialized tunnels,with the main fistula piercing above the deep external sphincter and the internal opening approaching the dentate line.Conventional surgical procedures for high complex anal fistulas remove most of the external sphincter and damage the anorectal ring.Postoperative loss of anal function can cause physical and mental damage.Transanal opening of the intersphincteric space(TROPIS)is an effective procedure that completely preserves the external anal sphincter.However,its clinical application is limited by challenges in the localization of the internal opening of a fistula and the high risk of complications.On the basis of our clinical experience,we modified the TROPIS procedure for the treatment of treating high complex anal fistulas.CASE SUMMARY A patient with a high complex anal fistula located above the anorectal ring underwent modified TROPIS,which involved sepsis drainage and identification of the internal opening in the intersphincteric space.The patient with the high complex anal fistula recovered well postoperatively,without any postoperative complications or anal dysfunction.Anal function returned to normal after 17 months of follow-up.CONCLUSION The modified TROPIS procedure is the most minimally invasive surgery for anal fistulas that minimally impairs anal function.It allows the complete removal of infected anal glands and reduces the risk of postoperative complications.Modified TROPIS via the intersphincteric approach is an alternative sphincter-preserving treatment for high complex anal fistulas.

Stem cell injection for complex anal fistula in Crohn’s disease: A single-center experience

BACKGROUND Despite tremendous progress in medical therapy and optimization of surgical strategies,considerable failure rates after surgery for complex anal fistula in Crohn’s disease have been reported.Therefore,stem cell therapy for the treatment of complex perianal fistula can be an innovative option with potential long-term healing.AIM To evaluate the results of local administration of allogenic,adipose-derived mesenchymal stem cells(darvadstrocel)for complex anal Crohn’s fistula.METHODS All patients with complex anal fistulas associated with Crohn’s disease who were amenable for definite fistula closure within a defined observation period were potential candidates for stem cell injection(darvadstrocel)if at least one conventional or surgical attempt to close the fistula had failed.Darvadstrocel was only indicated in patients without active Crohn’s disease and without presence of anorectal abscess.Local injection of darvadstrocel was performed as a standardized procedure under general anesthesia including single-shot antibiotic prophylaxis,removal of seton drainage,fistula curettage,closure of the internal openings and local stem cell injection.Data collection focusing on healing rates,occurrence of abscess and follow-up was performed on a regular basis of quality control and patient care.Data were retrospectively analyzed.RESULTS Between July 2018 and January 2021,12 patients(6 females,6 males)with a mean age of 42.5(range:26-61)years underwent stem cell therapy.All patients had a minimum of one complex fistula,including patients with two complex fistulas in 58.3%(7/12).Two of the 12 patients had horse-shoe fistula and 3 had one complex fistula.According to Parks classification,the majority of fistulas were transsphincteric(76%)or suprasphincteric(14%).All patients underwent removal of seton,fistula curettage,transanal closure of internal opening by suture(11/12)or mucosal flap(1/12)and stem cell injection.At a mean follow-up of 14.3(range:3-30)mo,a healing rate was documented in 66.7%(8/12);mean duration to achieve healing was 12(range:6-30)wk.Within follow-up,4 patients required reoperation due to perianal abscess(33.3%).Focusing on patients with a minimum follow-up of 12 mo(6/12)or 24 mo(4/12),long-term healing rates were 66.7%(4/6)and 50.0%(2/4),respectively.CONCLUSION Data of this single-center experience are promising but limited due to the small number of patients and the retrospective analysis.