Comparative Study on the Short- and Long-term Efficacy of Q-ISR, Traditional Sub-ISR, and t-ISR

January 19, 2026 updated by: Li Dawei, Fudan University
This comparative study evaluates the short- and long-term outcomes of Quadrant-based Intersphincteric Resection (Q-ISR) versus traditional subtotal ISR (Sub-ISR) and conventional/total ISR (t-ISR) in patients with ultra-low rectal cancer undergoing sphincter-preserving surgery, with short-term endpoints focusing on perioperative safety (operative time, blood loss, length of stay, and postoperative complications such as Clavien-Dindo grade ≥II, anastomotic leakage/stricture, and stoma reversal) and long-term endpoints assessing anorectal function recovery (LARS and Wexner scores after stoma closure) and oncologic efficacy (R0 resection, recurrence patterns, and survival outcomes), aiming to determine whether a quadrant-tailored resection strategy can better balance tumor control with anal function preservation.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

100

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • China
      • Shanghai, China
        • Recruiting
        • Fudan University Shanghai Cancer Center
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • (1) Rectal cancer diagnosed by digital rectal examination, colonoscopy, and combined biopsy pathology. (2) The distance from the lower edge of the tumor to the dentate line is 1.5-2.0 cm. (3) Good anal function before surgery. (4) The tumor does not infiltrate the intersphincteric space. (5) The tumor length is less than 3 cm, and the proportion of the tumor occupying the intestinal lumen is less than 1/3 of the circumference. (6) American Society of Anesthesiologists (ASA) score is ≤3.

Exclusion Criteria:

  • (1) Presence of distant metastasis. (2) Undifferentiated carcinoma or mucinous adenocarcinoma.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Q-ISR
Based on preoperative precise assessment and rectal endoscopic localization, selective resection of the internal sphincter is performed "by quadrant and quantificationally" according to the extent of lesion involvement, while striving to preserve the uninvolved quadrants and the external sphincter-levator ani complex. This aims to ensure R0 resection margins and oncological safety, while reducing the risk of low anterior resection syndrome (LARS) and accelerating the recovery of bowel control function.
Procedure: Quadrant-based Intersphincteric Resection
Q-ISR (Quadrant-based ISR): Based on preoperative precise assessment and rectal endoscopic localization, selective resection of the internal sphincter is performed "by quadrant and quantificationally" according to the extent of lesion involvement, while striving to preserve the uninvolved quadrants and the external sphincter-levator ani complex. This aims to ensure R0 resection margins and oncological safety, while reducing the risk of low anterior resection syndrome (LARS) and accelerating the recovery of bowel control function.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Wexner score
Time Frame: 3years
3years
LARS scores
Time Frame: 3years
3years
disease-free survival
Time Frame: 5years
5years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Fudan University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 7, 2026

Primary Completion (Estimated)

January 7, 2029

Study Completion (Estimated)

December 30, 2029

Study Registration Dates

First Submitted

January 19, 2026

First Submitted That Met QC Criteria

January 19, 2026

First Posted (Actual)

January 27, 2026

Study Record Updates

Last Update Posted (Actual)

January 27, 2026

Last Update Submitted That Met QC Criteria

January 19, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Q-ISR

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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