Condition category
Digestive System
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Mr Peter Lunniss


Contact details

Homerton University Hospital NHS Foundation Trust
Homerton Row
E9 6SR
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Management of idiopathic anal fistula using collagen: a prospective, randomised trial


Study hypothesis

Fibrin glue and porcine intestinal submucosa have been used as novel sphincter preserving techniques to heal anal fistulas, but the success of the former is highly variable, and widespread long term data are not available for the latter. The study aim was to assess the safety, feasibility and potential efficacy of another novel agent, cross-linked collagen, either as a solid implant or as fibres suspended in fibrin glue, to heal idiopathic anal fistulas.

Ethics approval

Ethics approval received from the East London and the City Research Ethics Committee in September 2004 (ref: P/03/870)

Study design

Prospective randomised single-blind controlled study

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Idiopathic anal fistulas deemed unsuitable for fistulotomy


This is a randomised single-blind controlled study performed at two london (UK) hospitals, the Royal London Hospital and the Homerton University Hospital.

Intervention 1: Solid Permacol® implant
Intevention 2: Milled Permacol® fibres suspended in fibrin glue

Permacol® (Tissue Science Laboratories plc) is a porcine derived acellular dermal sheet, predominately composed of Type I collagen (93 - 95%), with type III collagen and a small amount of elastin comprising the remainder. Sterile sheets 1.0 mm in thickness were used in this study. The alternative format is a 2.5 ml Permacol injection® (Tissue Science Laboratories plc), a 60% (wet weight/volume) suspension in saline of the cryogenically milled implant, with a defined particle size of 150 µm in diameter.

Fibrin glue: The 1.0 ml Tisseel Kit® - Two Component Fibrin Sealant (Baxter Healthcare Ltd, UK) was employed.

The implant was fashioned to the approximate dimensions of the fistula tract, and drawn into position using a suture, passed along a grooved fistula probe within the fistula tract.

The fibre suspension was prepared as follows: 1 ml Permacol injection® was injected into a 1.5 ml sterile Eppendorf Biopur® pipette tip (Eppendorf UK Limited, UK), and centrifuged at 1,100 rpm for 5 minutes. The saline supernatant was discarded, and the residual collagen fibres re-suspended in 1.0 ml calcium chloride solution supplied with the Tisseel Kit®. The individual components of the Tisseel Kit® were mixed, warmed in a Fibrinotherm™ (Baxter AG, Austria) and were then drawn up into two syringes (syringe 1: fibrinogen and aprotinin; syringe 2: thrombin and collagen fibres suspended in calcium chloride solution), which were subsequently placed in a Duploject™ (Baxter AG) two-syringe clip, where they shared a common plunger. A plastic double-lumen Y-connector joined these two syringes. This apparatus was then attached to a 21-gauge cannula, passed along a grooved fistula probe in the fistula tract.

Intervention type



Not Specified

Drug names


Primary outcome measures

1. Safety of procedure, defined as no acute perineal sepsis or anal incontinence at 3 months post intervention. Assessed by symptom and continence questionnaires, clinical examination, anal manometry, and endoanal ultrasound. All peformed at 3 months post-intervention.
2. Success of procedure assessed by symptom questionnaire and clinical examination at 3, 6, 9, 12 and 18-months post-intervention

Secondary outcome measures

The following were assessed by a patient questionnaire at 3-months post-intervention:
1. Time taken for perineal wound to heal
2. Time taken to return to work

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

All patients, over 18-years, with an idiopathic anal fistula, under the care of a single surgeon, in whom fistulotomy was deemed unsuitable (on the basis of the fistula type and level, threat to continence or patient choice).

Participant type


Age group




Target number of participants


Participant exclusion criteria

Patients with either clinical or radiological (magnetic resonance imaging) evidence of secondary tracts or acute sepsis were excluded from the trial until these had been eradicated, leaving a single primary tract.

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Homerton University Hospital NHS Foundation Trust
E9 6SR
United Kingdom

Sponsor information


Queen Mary, University of London (UK)

Sponsor details

c/o Mr P J Lunniss
Centre for Academic Surgery
Institute of Cell & Molecular Science
Barts & The London NHS Trust
United Kingdom

Sponsor type




Funder type


Funder name

Local NHS Trusts (UK) - the trial was performed on NHS patients requring a surgical intervention at their local trusts

Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

Tissue Science Laboratories plc (UK) - donated Permacol® unconditionally

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

1. 2011 results in

Publication citations

  1. Results

    Hammond TM, Porrett TR, Scott SM, Williams NS, Lunniss PJ, Management of idiopathic anal fistula using cross-linked collagen: a prospective phase 1 study., Colorectal Dis, 2011, 13, 1, 94-104, doi: 10.1111/j.1463-1318.2009.02087.x.

Additional files

Editorial Notes