FiLaC and PRGF-Endoret for Multi-recurrent Cryptoglandular Perianal Fistula (PLASMA Pilot Study)

NCT07810075 | Not Yet Recruiting

• 1 other identifier: PLASMA-2026-V1
• Study Type: interventional
• Target: 25
• Locations: 0 countries
• Sites: N/A

Brief Summary

Multi-recurrent cryptoglandular perianal fistula represents a challenging clinical problem with no established surgical solution after repeated failures. This pilot study evaluates the combination of fistula-tract laser closure (FiLaC) with perilesional injection of autologous platelet-rich growth factor (PRGF-Endoret) in 25 patients with a long-standing seton and no active sepsis. The primary outcome is clinical cure at 12 months. This study will provide preliminary safety and efficacy data to inform the design of a future randomised trial

Conditions

Perianal Fistula

Keywords

FiLaC; Fistula-tract laser closure; Platelet-rich plasma; PRGF-Endoret; Sphincter-preserving surgery; Laser surgery; Pilot study

Outcome Measures

Primary Outcomes (1)

• Measure: Clinical cure at 12 months

  Complete closure of the external opening without spontaneous or compression-induced drainage on clinical examination

  12 months after the procedure

Secondary Outcomes (5)

• Incidence of Postoperative Complications Classified by Clavien-Dindo Grade [Safety]

  30 days after the procedure

• Clinical cure at 6 months

  6 months

• Change in Faecal Continence Assessed by Wexner Continence Grading Scale

  Baseline (preoperative), 3, 6, and 12 months after the procedure

• Postoperative Pain Assessed by Visual Analogue Scale

  24 hours, 48 hours, 7 days, and 1 month after the procedure

• Fistula recurrence | 12 months • New surgical intervention

  12 months

Study Arms (1)

PLASMA Procedure

EXPERIMENTAL

Single ambulatory procedure under spinal anaesthesia: seton removal, FiLaC laser ablation (1470 nm, 12 W, 1 mm/s), direct primary suture closure of internal opening (Vicryl 2/0), perilesional injection of 7 ml autologous PRGF-Endoret. Intervention.

Procedure: Laser ablation of fistula tract using 1000-µm radial fibre (Biolitec, 1470 nm, 12 W, continuous, 1 mm/s withdrawal). Internal opening closed with Vicryl 2/0 suture in all patients

Interventions

Laser ablation of fistula tract using 1000-µm radial fibre (Biolitec, 1470 nm, 12 W, continuous, 1 mm/s withdrawal). Internal opening closed with Vicryl 2/0 suture in all patients PROCEDURE

Perilesional injection of 7 ml of autologous platelet-rich growth factor (PRGF-Endoret; BTI Biotechnology Institute, Vitoria, Spain), prepared from 36 ml of peripheral venous blood collected in four 9-ml sodium citrate tubes, centrifuged at 580 rpm for 8 minutes. The platelet-rich fraction, free of leucocytes and erythrocytes, is activated with autologous calcium chloride solution (0.05 ml of CaCl₂ 10% per ml of PRGF) immediately before injection and administered perilesionally around the fistula tract and internal opening closure site using a 23-gauge needle under direct vision.

PLASMA Procedure

Eligibility Criteria

• Age: Up to 18 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Cryptoglandular perianal fistula with at least 2 previous documented surgical failures
• Parks classification: intersphincteric or transsphincteric (low or high)
• Seton drain in situ for a minimum of 6 months at the time of surgery
• No active perianal sepsis (no purulent discharge, abscess or cellulitis)
• Single fistula tract on endoanal ultrasound (no secondary tracts)
• Identifiable internal opening on preoperative assessment
• Age 18 years or older
• Platelet count 100,000/µL or above on preoperative blood test
• Signed written informed consent

You may not qualify if:

• Crohn's disease or ulcerative colitis
• Suprasphincteric or horseshoe fistula
• Active perianal abscess or sepsis at the time of surgery
• Secondary fistula tracts on endoanal ultrasound
• Coagulopathy or thrombocytopenia (platelet count below 100,000/µL)
• Non-suspendable anticoagulant or antiplatelet therapy
• Active malignancy or severe immunosuppression
• Pregnancy
• Preoperative Wexner continence score 8 or above

Sponsors & Collaborators

• Complejo Hospitalario Universitario de Santiago: lead

Related Publications (7)

• VanderWeele TJ, Ding P. Sensitivity Analysis in Observational Research: Introducing the E-Value. Ann Intern Med. 2017 Aug 15;167(4):268-274. doi: 10.7326/M16-2607. Epub 2017 Jul 11.

  PMID: 28693043 BACKGROUND

• Cricri M, Miele A, Tropeano FP, Zoretti A, De Palma GD, Luglio G. A novel sphincter-sparing procedure for seton removal in complex perianal fistulas: the FiLaFlap technique. Tech Coloproctol. 2025 Dec 24;30(1):25. doi: 10.1007/s10151-025-03271-8.

  PMID: 41441911 BACKGROUND

• Cao D, Wang X, Zhang Y, Qian K, Yang N, Zhu M, Li Y, Wu G, Cui Z. Total fistula volume predicts surgical outcomes in complex perianal fistulizing Crohn's disease following fistula-tract laser closure: a single-center retrospective study. Tech Coloproctol. 2025 Feb 17;29(1):70. doi: 10.1007/s10151-024-03094-z.

  PMID: 39961900 BACKGROUND

• Adegbola SO, Sahnan K, Tozer P, Warusavitarne J. Emerging Data on Fistula Laser Closure (FiLaC) for the Treatment of Perianal Fistulas; Patient Selection and Outcomes. Clin Exp Gastroenterol. 2021 Dec 6;14:467-475. doi: 10.2147/CEG.S269464. eCollection 2021.

  PMID: 34908858 BACKGROUND

• Frountzas M, Stergios K, Nikolaou C, Bellos I, Schizas D, Linardoutsos D, Kontzoglou K, Vaos G, Williams AB, Toutouzas K. Could FiLaC be effective in the treatment of anal fistulas? A systematic review of observational studies and proportional meta-analysis. Colorectal Dis. 2020 Dec;22(12):1874-1884. doi: 10.1111/codi.15148. Epub 2020 Jun 18.

  PMID: 32445614 BACKGROUND

• Elfeki H, Shalaby M, Emile SH, Sakr A, Mikael M, Lundby L. A systematic review and meta-analysis of the safety and efficacy of fistula laser closure. Tech Coloproctol. 2020 Apr;24(4):265-274. doi: 10.1007/s10151-020-02165-1. Epub 2020 Feb 17.

  PMID: 32065306 BACKGROUND

• Fuschillo G, Pata F, D'Ambrosio M, Selvaggi L, Pescatori M, Selvaggi F, Pellino G. Failure rates and complications of four sphincter-sparing techniques for the treatment of fistula-in-ano: a systematic review and network meta-analysis. Tech Coloproctol. 2025 May 20;29(1):116. doi: 10.1007/s10151-025-03152-0.

  PMID: 40392371 BACKGROUND

MeSH Terms

Interventions

W 12

Central Study Contacts

Fernando Fernández López, MD PhD

CONTACT

+34981951358; fernando.fernandez@usc.es

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: This is a single-group interventional study in which all enrolled patients receive the same combined procedure (the PLASMA procedure) in a single operative session. There is no comparator arm, no randomisation, and no masking. The study follows a sequential enrolment design: consecutive eligible patients are included until the target sample of 25 is reached. The PLASMA procedure integrates two established techniques applied sequentially in the same surgical act: (1) fistula-tract laser closure (FiLaC), a sphincter-preserving ablation technique using a 1000-µm radially emitting diode laser probe (1470 nm, 12 W, continuous mode, withdrawal speed 1 mm/s); and (2) perilesional injection of autologous platelet-rich growth factor (PRGF-Endoret, 7 ml, activated with autologous calcium chloride). Internal opening closure by direct primary suture is performed in all patients prior to PRGF injection, as a mandatory protocolised step.

Study Record Dates

• First Submitted: August 28, 2026
• First Posted: September 9, 2026
• Study Start: October 1, 2026
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): March 30, 2029
• Last Updated: September 9, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share