Optimization and Standardization of Single-Port Robotic Transanal Minimally Invasive Surgery for Rectal Tumor Excision

Transanal Minimally Invasive Surgery (TAMIS) is a key minimally invasive technique for the treatment of early-stage rectal tumors and selected rectal lesions. It offers advantages such as organ preservation, avoidance of abdominal incisions, reduced complications, and accelerated postoperative recovery. However, conventional TAMIS procedures are often limited by instrument crowding and restricted operative vision, especially within the narrow confines of the rectum.

The single-port robotic platform provides enhanced flexibility, articulation, and visualization, offering a promising solution to the technical challenges of transanal surgery. This study aims to establish a standardized surgical protocol for SP-assisted Robotic TAMIS (SPR TAMIS) and to evaluate its clinical safety, feasibility, and short-term outcomes.

The investigators will incorporate real-world clinical cases and intraoperative videos to perform procedural decomposition, analyze key surgical steps, assess R0 resection rates, and measure recovery-related parameters. In parallel, the project will develop a dedicated educational module and performance evaluation tools to support skill transfer and broader clinical implementation.

This project is expected to facilitate the standardization of the Robotic TAMIS workflow, provide evidence for its clinical efficacy, and build a structured training platform. This project will help establish a standardized framework for robotic transanal surgery, improve patient care through precise and less invasive techniques, and foster broader clinical integration of advanced robotic platforms within Taiwan's surgical practice.

Inclusion criteria

• Patients with benign rectal lesions, including large adenomas or polyps not amenable to standard endoscopic removal
• Patients with recurrent or residual rectal lesions following incomplete endoscopic resection
• Patients with early-stage rectal cancer (clinical T1 tumors confined to the submucosa) with favorable histologic features (e.g., well-differentiated, no lymphovascular or perineural invasion)
• Select patients with T2 rectal cancer who are medically unfit for radical surgery or require local palliation
• Patients with clinically downstaged rectal cancer (e.g., cT0 or near-complete response) following neoadjuvant chemoradiotherapy, in whom TAMIS may be used for local excision to confirm pathological response

Exclusion criteria

• Patients undergoing excision of rectal neuroendocrine tumors
• Patients with bulky tumors or advanced disease (clinical T3-T4)
• Patients with radiologic or clinical evidence of nodal involvement
• Patients with high-risk histologic features (e.g., lymphovascular invasion, perineural invasion, poor differentiation), unless TAMIS is performed for palliative purposes or in patients unfit for radical surgery
• Patients in whom completion radical surgery is clearly indicated based on preoperative assessment