# Target trial on the outcomes of laparoscopic compared to robotic-assisted proctectomy in stage II–III rectal cancer

## TL;DR

This study compared laparoscopic and robotic-assisted proctectomy for rectal cancer and found similar outcomes, but robotic surgery had shorter hospital stays and fewer conversions to open surgery.

## Contribution

A target trial methodology was used to emulate a randomized clinical trial comparing laparoscopic and robotic-assisted proctectomy outcomes.

## Key findings

- Robotic-assisted proctectomy was associated with shorter hospital stays and fewer conversions to open surgery.
- Both surgical approaches showed similar clinical and pathologic outcomes, including CRM status and mortality rates.

## Abstract

Although outcomes of laparoscopic and robotic-assisted proctectomy have been compared, the superiority of one approach over another was not proven. We used the target trial methodology to emulate a randomized clinical trial comparing laparoscopic and robotic-assisted proctectomy for rectal cancer. Data from the NCDB (2015–2021) on patients with stage II–III rectal adenocarcinoma were collected. Patients were divided into two groups: laparoscopic proctectomy (LP) and robotic-assisted proctectomy (RP). The groups were matched for baseline patient and treatment confounders to obtain balanced groups, emulating the design of a randomized trial. The primary outcome was the pathologic outcomes of each surgical approach, including the status of circumferential resection margins (CRM), surgical margins, and number of examined lymph nodes. Secondary outcomes included conversion to open surgery, hospital stay, and 30- and 90-day mortality. After matching, 5631 patients were included in each group. The RP and LP groups had similar rates of positive CRM (10.5% vs. 9.4%, p = 0.072), positive surgical margins (6% vs. 6.3%, p = 0.528), examined lymph nodes number (median: 15 vs. 15, p = 0.105), 30-day mortality (0.7% vs. 0.9%, p = 0.405), 90-day mortality (1.5% vs. 1.8%, p = 0.333), and unplanned 30-day readmission (6.6% vs. 6.2%, p = 0.477). RP was associated with shorter hospital stay (median: 4 vs. 5 days, p < 0.001) and lower rate of conversion to open surgery (5.8% vs. 13.6%, OR: 0.39, 95%CI 0.34–0.45, p < 0.001). This target trial found RP and LP for rectal cancer associated with similar clinical and pathologic outcomes. RP was associated with fewer conversions and shorter hospital stays than LP.

The online version contains supplementary material available at 10.1007/s13304-025-02446-0.