The laparoscopic approach for laparoscopic total mesorectal excision (L-TME) results improved short-term outcomes and provides a clearer intraoperative view compared with the open approach in a deep and narrow pelvis. Preliminary results from the COLOR II trial confirmed improved patient recovery and similar safety, same resection margins and completeness of resection using L-TME compared with the results achieved with open surgery. Results from the CLASICC trial supported the use of laparoscopic surgery for colorectal cancer and showed no difference between laparoscopically-assisted TME and conventional open resection at 10 years post-procedure in terms of overall survival, disease-free survival and local recurrence.
Despite these positive clinical outcomes for L-TME, laparoscopic resection of rectal cancer, especially in a deep and narrow pelvis, is technically demanding and demands a long learning curve. Technical limitations include limited mobility of straight laparoscopic instruments and associated loss of dexterity, unstable camera view and compromised ergonomics for the surgeon. These limitations could explain the conversion rate which remained at 17% in the last COLOR II trial.2 In order to avoid this drawback, we have described for patients with high-risk of conversion, the trans-anal endoscopic proctectomy (TAEP) approach performed with the Transanal Endoscopic Operation (TEO) device. This trans-anal procedure is also called Trans anal minimally invasive surgery (TAMIS) if a laparoscopic port is used.
Robotic technology was developed to reduce these limitations and offers the advantages of intuitive manipulation of laparoscopic instruments with wrist articulation, a 3-dimensional field of view, a stable camera platform with zoom magnification, dexterity enhancement and an ergonomic operating environment. A major advantage of the robotic approach is the surgeon's simultaneous control of the camera and of the two or three additional instruments. This advantage facilitates traction and counter-traction. The technological advantages of robotic surgery should also allow a finer dissection in a narrow pelvic cavity. However, total robotic surgery for rectal cancer is still technically challenging and involves two operative fields (splenic flexure and rectum), potential collision of the robotic arms and lack of tactile feedback.
Reports of robotic and laparoscopic rectal cancer surgery outcomes showed similar intraoperative results and morbidity, postoperative recovery and short-term oncologic outcomes. However, longer operation times have been described as a disadvantage of the robotic system, compared with conventional laparoscopy. On the other hand, all meta-analyses comparing robotic total mesorectal excision (R-TME) and L-TME concluded in reduction of the conversion rate.
Since 2007, the rectal surgery with robotic assistance is booming. To date, seven meta-analyses have been published. All show that the robot exceeds laparoscopy to reduce the conversion rate. The last two Meta-analyzes that had gathered more than 800 patients undergoing robotic surgery have again highlighted the contribution of the robot to secure the radial margin and decrease sexual sequelae. However, there is not so far from Phase 3 randomized trial dealing with the subject. The ROLARR protocol was completed in late 2014 (Ph III laparoscopy / Robot), the first results are published in late 2015.
The interest of a European multicentre ambispective (retrospective and prospective) database is fundamental because this early work suggests that the robot can make more for specific subgroups of patients, particularly in high surgical risk patients (Male, narrow pelvis, high BMI, mesorectal fat, large tumor of the anterior and middle third). The largest series of R-TME stems from the US national cancer database (965 patients operated by R-TME) and confirms a 9.5% conversion rate compared to 16.4% with L-TME (p < 0.001).