EP372 - Early experience of SP-robot-TAMIS comparing with conventional TAMIS for rectal neoplasm

Purpose/Background: Transanal approach for rectal neoplasm have evolved from transanal local excision, transanal endoscopic microsurgery (TEM), to transanal minimally invasive surgery (TAMIS). TAMIS was introduced in 2020, which employs a single port laparoscopic approach to access the rectum for tumor resection. However, using straight instruments without joints still poses challenges in the dissection of tumors located in the narrow and curved anal canal.
Recently, robotic surgery has provided improved maneuverability through articulating instruments, and better visualization, which helps in accessibility and efficiency. The advancements in single port (SP) robot platform aim to maximize these benefits and the transanal approach.
This study aims to conduct a comparative analysis of surgical efficiency and short-term clinical and oncological outcomes between laparoscopic TAMIS and SP robotic platforms for rectal tumor resections.

Methods/Interventions: This study was a retrospective, multicenter study that enrolled patients who underwent single port laparoscopic (LAP) or robotic TAMIS (SPR) for rectal tumors at Seoul St.Mary’s hospital and St.Vincent’s hospital from January 2016 to August 31, 2024. Preoperative evaluation was performed using endoscopy and abdominal image such as CT or MRI. Patients with clinical stage T1 orN0, well to moderately differentiated tumor, and low-risk feature were included.

Results/Outcomes: A total of 42 patients underwent procedures at two institutions, including 15 in the SPR group and 27 in the LAP group. There was no significant difference in age and gender distribution between the two groups (SPR vs LAP; 51.13±15.34 vs. 51.04±12.39, p=0.984). The distance from the anal verge to the rectal tumor was 6.14±2.08 in the SPR group and 7.37±2.53 in the LAP group, with no significant difference. Intraoperative outcomes included that the SPR group had 13 patients (86.7%) in the prone position, while the LAP group had 24 patients (88.9%) in the lithotomy position. There were no significant differences in the mean operative time between the two groups (SPR vs. LAP, 61.20±32.31 vs. 50.26±24.09; p=0.264). All patients underwent full thickness excision, and there were no intraoperative complications. In the postoperative and pathological results, the lateral and basal margins were obtained without significant differences between the two groups, and all resection margins were negative. The postoperative length of hospital stay was significantly shorter in the SPR group (1.67±1.05 days) than in the LAP group (3.33±0.734 days).

Conclusion/Discussion: In conclusion, this study highlights the comparative effectiveness of SPR-TAMIS versus LAP-TAMIS for rectal tumor resections. Both techniques demonstrated no significant differences in clinical and oncological outcomes. These findings suggest that SPR platforms may offer enhanced efficiency and postoperative recovery, especially considering the challenges associated with accessing the narrow anal canal.

Intraoperative outcomes comparing SPR-TAMIS to LAP-TAMIS
There were no significant differences in the mean operative time between the two groups (SPR vs. LAP, 61.20±32.31 vs. 50.26±24.09; p=0.264). All patients underwent full thickness excision, and there were no intraoperative complications

clinical and pathological outcomes comparing SPR-TAMIS to LAP-TAMIS
In the postoperative and pathological results, the lateral and basal margins were obtained without significant differences between the two groups, and all resection margins were negative. The postoperative length of hospital stay was significantly shorter in the SPR group (1.67±1.05 days) than in the LAP group (3.33±0.734 days).