Robotic vs. laparoscopic intersphincteric resection for low rectal cancer: a case matched study reporting a median of 7-year long-term oncological and functional outcomes

Aim of this study was to compare operative, long-term oncological and functional outcomes of laparoscopic (LISR) and robotic (RISR) intersphincteric resection in low-lying rectal cancer. Retrospective analysis of prospectively maintained database was performed. 115 cases (LISR, n = 55; RISR, n = 60) were performed by a single surgeon (January 2011–January 2020). Clinical characteristics did not differ between the groups. Operating time was longer in RISR (160.0 ± 45.7 vs. 205.0 ± 36.5 min, p = 0.035). There was no conversion in RISR, whereas in LISR, two patients (3.6%) converted to open surgery. Complete mesorectum was 61.8% and 83.3% for LISR and RISR ( p = 0.046), respectively. Circumferential radial margin involvement was 10.9% and 8.3% in LISR and RISR ( p = 0.365), respectively. Median follow-up was 82.8 (30–138) months for LISR and 83.6 (30–138) months for RISR. Three-, five-, and seven-year overall survival rates (OS) for LISR and RISR were: 88.6%, 80.4%, 73.4% and 90.4%, 86.3%, 76.9%, respectively. Three-, five-, and seven-year disease-free survival (DFS) rates for LISR and RISR were 80.5%, 75.2%, 70.4% and 84.4%, 81.4%, 79.8% ( p = 0.328), respectively. Three-, five-, and seven-year local recurrence-free survival rates in LISR and RISR were: 96.1%, 92.6%, 88.4% and 96.7%, 94.2%, 90.4% ( p = 0.573), respectively. Mean Wexner score for LISR ( n = 32) and RISR ( n = 40) was: 10.5 ± 4.7 and 9.8 ± 4.2 ( p = 0.782), respectively. Colostomy-free survival in LISR and RISR was: 3 years 94.5%/95.2%, 5 years 89.1%/91.7%, and 7 years 83.6%/85.0%. RISR is associated with better mesorectal integrity, no conversion, and lower postoperative complication rate. RISR has longer operation time. Oncological and anorectal functional outcomes are similar in both groups.