Complete intersphincteric longitudinal muscle excision May Be key to reducing local recurrence during...

Area of Science:

• Colorectal surgery
• Surgical oncology
• Rectal cancer treatment

Background:

• Total mesorectal excision (TME) is standard for rectal cancer, but intersphincteric resection (ISR) lacks standardized technical definitions and evaluation methods.
• This study introduces a complete ISR procedure and evaluates total intersphincteric longitudinal muscle excision (TILME) for ISR completeness and recurrence reduction.

Purpose of the Study:

• To define and evaluate a complete ISR procedure using total intersphincteric longitudinal muscle excision (TILME).
• To assess the impact of TILME completeness on local recurrence rates in rectal cancer patients undergoing ISR.

Main Methods:

• 1080 patients with rectal adenocarcinoma undergoing robot-assisted low anterior resection (LAR) were analyzed over 10 years.
• Propensity-score matching created ISR and standard LAR groups (1:1) and ISR subgroups (partial, subtotal, total; 2:2:1).
• Specimen and video/photo records were re-evaluated to confirm TILME completeness.

Main Results:

• Complete TILME was achieved in 84.5% of ISR patients.
• Incomplete TILME was the sole independent predictor of increased 5-year local recurrence (OR=23.385, p=0.03).
• Incomplete TILME correlated with surrounding adipose tissue, coloanal anastomosis, and total ISR (p<0.05). Acceptable incontinence and manometry scores were observed post-surgery.

Conclusions:

• Completeness of TILME is an independent indicator for successful ISR.
• Achieving complete TILME significantly reduces local recurrence after lower rectal cancer surgery.