RecruitingPhase 2NCT07371273

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

Sponsor

Fudan University

Enrollment

100 participants

Start Date

Jan 7, 2026

Study Type

INTERVENTIONAL

Conditions

Colorectal, Cancer

Summary

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.

Eligibility

Min Age: 18 YearsMax Age: 75 Years

Inclusion Criteria1

(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 Criteria1

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

Interventions

PROCEDUREQuadrant-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.