[Preliminary application study of robot-assisted pelvic exenteration in the treatment of low locally advanced or recurrent rectal cancer].

Objective: To explore the feasibility and preliminary clinical experience of robot-assisted pelvic exenteration (PE) in the treatment of locally advanced (LARC) and recurrent (LRRC) rectal cancer. Method: A descriptive case series research method was adopted. Inclusion criteria included: (1) Age 18-80 years old; (2) Preoperative puncture biopsy performed through endoscopy, and a pathological diagnosis of rectal malignant tumor; (3) Preoperative imaging examinations confirming locally advanced (cT4b stage) or locally recurrent rectal cancer, with tumor location in the pelvic cavity; (4) Physical condition: ECOG score ≤1 point, and radical resection being feasible after assessment. The data for five patients with LARC or LRRC who underwent pelvic exenteration (PE) using the da Vinci robotic surgical system in the Department of Anorectal Surgery, the Second Affiliated Hospital of Naval Medical University (Shanghai Changzheng Hospital) from January, 2024 to January, 2025 were collected retrospectively. The mean age was (46.8±7.7) years, with 3 males and 2 females, who comprised 2 cases of LARC and 3 cases of LRRC. Two patients received preoperative radiotherapy, and 4 patients received preoperative chemotherapy. The average body mass index was (21.5±2.7) kg/m². According to the American Society of Anesthesiologists (ASA) classification, 2 cases were grade II and 3 cases were grade III. Results: All patients with LARC or LRRC successfully underwent robot-assisted PE. The average operation time was (496.4±139.5) minutes; the average intraoperative blood loss was (72.0±29.5) ml; the average postoperative exhaust time was (50.0 ±13.6) hours; and the average postoperative defecation time was(64.2±15.3) hours. Mean early postoperative VAS pain scores was (3.6±1.5) points. Three patients underwent primary intestinal anastomosis, and 2 patients underwent colonic single-lumen ostomy. All 5 patients underwent urinary system reconstruction, among which 2 underwent ureterovesical reimplantation, 1 underwent percutaneous ureterostomy, 1 underwent ileal conduit replacement of bladder, and 1 underwent direct bladder suture. After surgery, except for 1 case of pelvic infection with effusion (Clavien-Dindo grade IIIa), there were no obvious postoperative complications. Postoperative pathological results showed that all patients achieved R0 resection, including 1 case of T4a stage and 4 cases of T4b stage (all involving urogenital organs or tissues), and 3 cases of N0 stage and 2 cases of N1 stage, with a maximum tumor diameter of (4.7±1.9) cm. The median postoperative follow-up time was 11 (range 7 to 17) months, and no patient experienced local recurrence. Conclusion: The above short-term preliminary results of robot-assisted PE in the treatment of LARC or LRRC within the pelvic cavity indicate that it is both safe and feasible.