Retrospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 28, 2021; 27(24): 3643-3653
Published online Jun 28, 2021. doi: 10.3748/wjg.v27.i24.3643
Stem cell injection for complex anal fistula in Crohn’s disease: A single-center experience
Oliver Schwandner
Oliver Schwandner, Department of Proctology, Krankenhaus Barmherzige Brueder, Regensburg 93049, Germany
Author contributions: Schwandner O performed the research and wrote the paper.
Institutional review board statement: According to the Ethics Committee of the Bavarian State Chamber of Physicians retrospective reviews of anonymized patient data do not require ethical approval, No. 2021-1022.
Informed consent statement: Patients were not required to give informed consent to the study because the retrospective analysis used anonymized clinical data that were obtained after each patient agreed to treatment by written consent.
Conflict-of-interest statement: The author had honoraria from Takeda and Medtronic for invited presentations during advisory board meetings and satellite symposia. Neither funding nor financial support was administered for the current study.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Oliver Schwandner, FASCRS, MD, Professor, Department of Proctology, Krankenhaus Barmherzige Brueder, Pruefeninger Str 86, Regensburg 93049, Germany.
Received: January 9, 2021
Peer-review started: January 9, 2021
First decision: January 23, 2021
Revised: March 10, 2021
Accepted: June 4, 2021
Article in press: June 4, 2021
Published online: June 28, 2021
Research background

Despite significant progress in medical therapy and surgical options, definite surgery for complex anal fistula in Crohn’s disease remains challenging.

Research motivation

At present, failure rates after surgery for complex anal fistula associated with Crohn’s disease are still high, and surgical options in patients with recurrent and/or multi-tract fistula are limited.

Research objectives

The primary objective was to assess whether local stem cell injection is associated with acceptable healing rates in a routine clinical setting.

Research methods

Providing strict inclusion and exclusion criteria, 12 patients with complex anal fistulas associated with Crohn’s disease underwent local application of allogenic, adipose-derived mesenchymal stem cells (darvadstrocel). Darvadstrocel was only indicated in patients without active Crohn’s disease confirmed by ileocolonoscopy and without presence of anorectal abscess. Study design was retrospective and routine clinical data were analyzed.

Research results

Twelve patients (6 females, 6 males) with complex anal fistula associated with Crohn’s disease underwent fistula curettage, transanal closure of internal openings and local darvadstrocel administration. Fifty-eight percent of patients had two complex fistulas, and seventy-six percent of the fistulas were transsphincteric. After a mean follow-up of 14.3 mo, a healing rate of 66.7% (8/12) was documented. Perianal abscess occurred in 33.3% of patients during follow-up.

Research conclusions

This single-center experience demonstrates that local stem cell injection for complex perianal fistulizing disease is safe and provides acceptable healing rates. However, conclusions are limited due to the small number of patients and the retrospective study design.

Research perspectives

Based on the current results, local stem cell injection could be a new “puzzle piece” for effective treatment of complex anal fistulas associated with Crohn’s disease.