Evaluation of the Ileo-anal Pouch in FAP (ENDOPOL)

NCT07726771 | Recruiting

• 2 other identifiers: RD25/099365649
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

This international, multi-centre randomised controlled trial will compare dye-based chromoendoscopy with virtual chromoendoscopy, using NBI/BLI, for adenoma detection during routine surveillance pouchoscopy in adults with familial adenomatous polyposis (FAP) and an ileal pouch-anal anastomosis (IPAA). The estimated study duration is 2 years. Participants will undergo their usual scheduled pouchoscopy, performed by endoscopists experienced in FAP. Before the procedure, they will be randomised 1:1 to dye-based or virtual chromoendoscopy. Adenomas requiring endoscopic treatment will be removed during the same procedure according to standard practice. To our knowledge, no previous study has directly compared these techniques in this setting. Current guidelines recommend surveillance in patients with FAP and a pouch and permit dye-spray chromoendoscopy, but do not specify whether dye-based or virtual chromoendoscopy should be preferred. Practice varies between centres: virtual chromoendoscopy is commonly used at St Mark's Hospital, while some European centres primarily use dye-based chromoendoscopy. This study therefore aims to standardise practice and generate evidence to inform future surveillance strategies. Eligible patients will be adults aged ≥18 years with FAP, defined by a proven APC germline mutation or a clinical diagnosis of \>100 colorectal adenomas with a positive family history, and who have undergone IPAA after primary proctocolectomy or secondary proctectomy following IRA/ISA. Patients will be identified through routine endoscopy booking systems. Those who have consented to email communication from the Polyposis Registry team will receive a Participant Information Sheet in advance. They will be approached again on the day of their procedure, given the opportunity to ask questions, and consented before randomisation. Patients who do not consent will undergo their planned pouchoscopy as normal, without study randomisation. Patients lacking capacity to consent will not be approached. Randomisation will be performed using an independent computer-generated programme within Castor EDC, with allocation in a 1:1 ratio. Block randomisation will ensure balanced distribution between arms within each centre, and stratification by centre will account for differences in patient characteristics and local practice. Blinding is not feasible because dye-based and virtual chromoendoscopy have visually distinct appearances. During pouchoscopy, the pre-pouch ileum, pouch body and rectal cuff will be carefully inspected. In the dye-based arm, indigo carmine will be applied using a spray catheter before withdrawal and mucosal inspection. In the virtual chromoendoscopy arm, inspection will be performed using NBI/BLI according to local platform availability. The endoscope will be advanced to the pre-pouch ileum, followed by systematic withdrawal and spiral mucosal inspection. Lesions will be documented by size and location, including pouch body and rectal remnant/rectal cuff, using a polyp burden scoring table. Retroflexion will be performed to assess the rectal cuff. Polyp size will be estimated in millimetres, supported where appropriate by biopsy forceps of known size. Adenomas will be resected using standard polypectomy techniques where indicated, including polyps \>5 mm in the pouch body, \>2 mm in the rectal cuff, or lesions suspicious for high-grade dysplasia or early cancer. Because assessment of small polyps can vary between endoscopists, particularly for lesions \<5 mm, endoscopic images will be used to assess inter-rater and intra-rater reliability for polyp burden and size. If reliability is acceptable, smaller polyps will be included and reported. Quality parameters will be collected for each procedure, including adjusted Boston Bowel Preparation Scale assessment for the pouch and total procedural time. Procedural time will include scope introduction, irrigation, dye application where applicable, withdrawal and inspection, retroflexion, and removal and retrieval of polyps. Post-procedure follow-up will follow routine care. Patients will be asked to monitor for adverse events after pouchoscopy and contact the hospital if needed. Future surveillance will be scheduled according to each centre's usual policy. Study data will be held in routine hospital systems accessible to the patient's usual clinical team and in a study file. Participants will be assigned a study number. No identifiable patient information will leave the Trust or be accessible to anyone outside the usual care team. Anonymised data will be entered into Castor EDC. Pseudonymised data will be transferred to the central study team at Amsterdam University Medical Center under an existing data transfer agreement for pooled analysis. The study does not expose participants to risks beyond routine surveillance pouchoscopy. There is no direct individual benefit but findings may benefit future patients with FAP and families by improving evidence.

Conditions

Pouches, Ileoanal; Familial Adenomatous Polyposis (FAP)

Keywords

FAP; Endoscopy; Chromoendoscopy; Dye spray; Pouch

Outcome Measures

Primary Outcomes (1)

• Incidence of clinically relevant adenomas greater than 5 mm in the ileo-anal pouch

  Incidence of clinically relevant adenomas greater than 5 mm in the ileo-anal pouch comparing dye-based chromoendoscopy with virtual chromoendoscopy using NBI/BLI

  Periprocedural

Secondary Outcomes (8)

• Incidence of advanced neoplasia in the pouch

  Periprocedural

• Incidence of adenomas measuring 2-4 mm, 5-9 mm and ≥10 mm

  Periprocedural

• Number of adenomas in the rectal remnant and anal mucosa

  Periprocedural

• InSiGHT Polyposis Staging System score

  Periprocedural

• Number of polypectomies performed

  Periprocedural

Study Arms (2)

Chromoendoscopy

ACTIVE COMPARATOR

Chromoendoscopy arm using dye spray

Other: Chromoendoscopy (Indigo Carmine)

Virtual Chromoendoscopy

ACTIVE COMPARATOR

Virtual chromoendoscopy arm using narrow-band imaging (NBI)

Other: Virtual Chromoendoscopy

Interventions

Virtual Chromoendoscopy OTHER

Virtual chromoendoscopy using narrow-band imaging (NBI)

Virtual Chromoendoscopy

Chromoendoscopy (Indigo Carmine) OTHER

Chromoendoscopy using dye spray

Chromoendoscopy

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• ALL of the following:
• Diagnosis of FAP i.e., at least one of following:
• Genetic diagnosis: proven APC germline mutation OR
• Clinical diagnosis: \>100 colorectal adenomas in combination with a positive family history of FAP
• Have an ileal-pouch anal anastomosis (IPAA), either after primary proctocolectomy or secondary proctectomy after initial colectomy and ileorectal or ileosigmoidal anastomosis (IRA/ISA)
• Age ≥ 18 years

You may not qualify if:

• ANY of the following
• Diagnosis of FAP i.e., at least one of following:
• Genetic diagnosis: proven APC germline mutation OR
• Clinical diagnosis: \>100 colorectal adenomas in combination with a positive family history of FAP
• Have an ileal-pouch anal anastomosis (IPAA), either after primary proctocolectomy or secondary proctectomy after initial colectomy and ileorectal or ileosigmoidal anastomosis (IRA/ISA)
• Age ≥ 18 years

Sponsors & Collaborators

• London North West Healthcare NHS Trust: lead
• Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA): collaborator

Study Sites (1)

St Mark's Hospital Polyposis Registry (St Mark's Centre for Familial Intestinal Cancer)

London, London, N10 7NS, United Kingdom

RECRUITING

Related Publications (11)

• Wang L, Mannalithara A, Singh G, Ladabaum U. Low Rates of Gastrointestinal and Non-Gastrointestinal Complications for Screening or Surveillance Colonoscopies in a Population-Based Study. Gastroenterology. 2018 Feb;154(3):540-555.e8. doi: 10.1053/j.gastro.2017.10.006. Epub 2017 Oct 12.

  PMID: 29031502 BACKGROUND

• Lai EJ, Calderwood AH, Doros G, Fix OK, Jacobson BC. The Boston bowel preparation scale: a valid and reliable instrument for colonoscopy-oriented research. Gastrointest Endosc. 2009 Mar;69(3 Pt 2):620-5. doi: 10.1016/j.gie.2008.05.057. Epub 2009 Jan 10.

  PMID: 19136102 BACKGROUND

• Lynch PM, Morris JS, Wen S, Advani SM, Ross W, Chang GJ, Rodriguez-Bigas M, Raju GS, Ricciardiello L, Iwama T, Rossi BM, Pellise M, Stoffel E, Wise PE, Bertario L, Saunders B, Burt R, Belluzzi A, Ahnen D, Matsubara N, Bulow S, Jespersen N, Clark SK, Erdman SH, Markowitz AJ, Bernstein I, De Haas N, Syngal S, Moeslein G. A proposed staging system and stage-specific interventions for familial adenomatous polyposis. Gastrointest Endosc. 2016 Jul;84(1):115-125.e4. doi: 10.1016/j.gie.2015.12.029. Epub 2016 Jan 6.

  PMID: 26769407 BACKGROUND

• Huneburg R, Heling D, Kaczmarek DJ, van Heteren P, Olthaus M, Fimmers R, Berger M, Coch C, Lau JF, Kristiansen G, Weismuller TJ, Spier I, Aretz S, Strassburg CP, Nattermann J. Dye chromoendoscopy leads to a higher adenoma detection in the duodenum and stomach in patients with familial adenomatous polyposis. Endosc Int Open. 2020 Oct;8(10):E1308-E1314. doi: 10.1055/a-1220-6699. Epub 2020 Sep 22.

  PMID: 33015332 BACKGROUND

• Hurley JJ, Thomas LE, Walton SJ, Thomas-Gibson S, Haycock A, Suzuki N, Mort M, Williams G, Morgan M, Clark SK, Sampson JR, Dolwani S. The impact of chromoendoscopy for surveillance of the duodenum in patients with MUTYH-associated polyposis and familial adenomatous polyposis. Gastrointest Endosc. 2018 Oct;88(4):665-673. doi: 10.1016/j.gie.2018.04.2347. Epub 2018 Apr 24.

  PMID: 29702101 BACKGROUND

• Dekker E, Boparai KS, Poley JW, Mathus-Vliegen EM, Offerhaus GJ, Kuipers EJ, Fockens P, Dees J. High resolution endoscopy and the additional value of chromoendoscopy in the evaluation of duodenal adenomatosis in patients with familial adenomatous polyposis. Endoscopy. 2009 Aug;41(8):666-9. doi: 10.1055/s-0029-1214980. Epub 2009 Aug 10.

  PMID: 19670132 BACKGROUND

• van Leerdam ME, Roos VH, van Hooft JE, Dekker E, Jover R, Kaminski MF, Latchford A, Neumann H, Pellise M, Saurin JC, Tanis PJ, Wagner A, Balaguer F, Ricciardiello L. Endoscopic management of polyposis syndromes: European Society of Gastrointestinal Endoscopy (ESGE) Guideline. Endoscopy. 2019 Sep;51(9):877-895. doi: 10.1055/a-0965-0605. Epub 2019 Jul 23.

  PMID: 31342472 BACKGROUND

• Pasquer A, Benech N, Pioche M, Breton A, Rivory J, Vinet O, Poncet G, Saurin JC. Prophylactic colectomy and rectal preservation in FAP: systematic endoscopic follow-up and adenoma destruction changes natural history of polyposis. Endosc Int Open. 2021 Jul;9(7):E1014-E1022. doi: 10.1055/a-1467-6257. Epub 2021 Jun 17.

  PMID: 34222624 BACKGROUND

• Friederich P, de Jong AE, Mathus-Vliegen LM, Dekker E, Krieken HH, Dees J, Nagengast FM, Vasen HF. Risk of developing adenomas and carcinomas in the ileal pouch in patients with familial adenomatous polyposis. Clin Gastroenterol Hepatol. 2008 Nov;6(11):1237-42. doi: 10.1016/j.cgh.2008.06.011. Epub 2008 Oct 10.

  PMID: 18848811 BACKGROUND

• Tajika M, Niwa Y, Bhatia V, Tanaka T, Ishihara M, Yamao K. Risk of ileal pouch neoplasms in patients with familial adenomatous polyposis. World J Gastroenterol. 2013 Oct 28;19(40):6774-83. doi: 10.3748/wjg.v19.i40.6774.

  PMID: 24187452 BACKGROUND

• Tudyka VN, Clark SK. Surgical treatment in familial adenomatous polyposis. Ann Gastroenterol. 2012;25(3):201-206.

  PMID: 24714154 BACKGROUND

MeSH Terms

Conditions

Adenomatous Polyposis Coli

Interventions

Indigo Carmine

Condition Hierarchy (Ancestors)

Adenomatous Polyps; Adenoma; Neoplasms, Glandular and Epithelial; Neoplasms by Histologic Type; Neoplasms; Colorectal Neoplasms; Intestinal Neoplasms; Gastrointestinal Neoplasms; Digestive System Neoplasms; Neoplasms by Site; Neoplastic Syndromes, Hereditary; Digestive System Diseases; Gastrointestinal Diseases; Colonic Diseases; Intestinal Diseases; Intestinal Polyposis; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Intervention Hierarchy (Ancestors)

Indoles; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds

Study Officials

• Andre Latchford, MBBS PhD FRCP

  LONDON NORTH WEST UNIVERSITY HEALTHCARE NHS TRUST

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Andrew Latchford, MBBS PhD FRCP

CONTACT

+442088643232; andrew.latchford@nhs.net

Benjamin Zare, MBChB (Hons) MRCP

CONTACT

+442088643232; b.zare@nhs.net

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Randomisation is performed by an independent computer-generated random numbers program (Castor EDC). All participating centres have access to this tool. Prior to pouchoscopy, randomisation will be performed prior to the procedure in a 1:1 ratio. Block size in a 2-4-6 randomisation will be used to ensure same distributions (dye-based chromoendoscopy versus NBI) for each centre. Stratification by centre will be performed to account for potential variations in patient characteristics and procedural protocols among different centres. Blinding is not feasible due to the distinct visual aspects involved in virtual and dye chromoendoscopy, which is also the case for patients undergoing pouchoscopy under mild sedation.

Study Record Dates

• First Submitted: July 10, 2026
• First Posted: July 24, 2026
• Study Start: July 9, 2026
• Primary Completion (Estimated): July 9, 2031
• Study Completion (Estimated): July 9, 2031
• Last Updated: July 24, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)