Preoperative Localization, Margins, and Intraoperative Endoscopy in Minimally Invasive Sigmoid Colectomy: A Matched Cohort

Abstract

Introduction: Preoperative localization (endoscopic tattoo or clip) is widely used in laparoscopic colorectal surgery to guide resection margins, yet its influence on long-term outcomes is uncertain. We compared minimally invasive sigmoid colectomy (MISC) performed with versus without localization.

Methods: We retrospectively reviewed elective MISC at a single center from January 2016 to December 2019. Demographics, localization technique, operative data, hospital stay, complications, and 5-year overall survival (OS) and disease-free survival (DFS) were collected. Propensity-score matching generated two balanced cohorts.

Results: Of 296 eligible patients, 99 matched pairs were analyzed. Localization yielded wider pathological margins (4.0 cm versus 3.0 cm, P < 0.001) and fewer intraoperative colonoscopies (3.0% versus 10.1%, P = 0.004). Five-year OS (89.7% versus 89.2%, P = 0.38) and DFS (82.0% versus 72.7%, P = 0.09) were similar between groups. Margin length showed limited prognostic value (OS area under the curve, 0.592; DFS area under the curve, 0.541).

Conclusions: Localization during MISC was associated with wider resection margins and a lower frequency of intraoperative colonoscopy. No statistically significant differences were observed in 5-year OS/DFS; the study was not powered to detect small survival differences.

Keywords: Colon cancer; Colonoscopy; Colorectal surgery; Laparoscopy; Metallic clip; Minimally invasive surgery; Tattooing.