Robotic Versus Laparoscopic Total Mesorectal Excision for Middle Rectal Cancer: Functional Results from a Randomized Pilot Study

Abstract Urinary and sexual dysfunctions are recognized as serious complications that affect patients' quality of life after mid-rectal cancer surgery; however, studies that focus on the urogenital function after robot-assisted compared to laparoscopic rectal cancer surgery are limited. To compare functional outcomes between patients undergoing robotic and laparoscopic approaches for middle rectal cancer submitted to neoadjuvant chemoradiation. Patients with mid-rectal cancer were prospectively enrolled in this phase-II randomized trial to robotic or laparoscopic total mesorectal excision (TME). After eligibility was confirmed and chemoradiation therapy was completed, patients underwent randomization in a 2:1 ratio (robotic: laparoscopic TME groups) with stratification according to gender (male or female) and body mass index (BMI) < 35 or ≥ 35. The assessment of urinary function was carried out using complete urodynamic study, urinary symptoms questionnaire (International Consultation on Incontinence Questionnaire – Short Form [ICIQ-SF]), and urinary continence questionnaire (International Prostate Symptom Score [I-PSS]). The complete urodynamic study and the questionnaires were carried out before the start of any treatment and after neoadjuvant therapy (before surgery) and was repeated in the 1st, 3rd, 6th, 12th, 18th and 24th postoperative months. The analysis of male sexual function was carried out using International Index of Erectile Function (IIEF-5) questionnaire. Female sexual function was analyzed using the specific Female Sexual Functiona Index (FSFI) questionnaire, and the Quality-of-Life Questionnaire Core 30 (QLQ-C30) and Quality-of-Life Questionnaire - Colorectal Cancer 29 (QLQ-CR29 were applied to patients at the same time as the sexual and urinary function assessment questionnaires. Between 2017 and 2022, 32 patients entered the trial, and 30 were eligible to participate (2 patients were excluded due to screening failure). Among them, only 21 were randomized to robotic or laparoscopic group. Only 9 (42.9%) and 12 patients (57.1%) underwent urodynamic testing at the 3rd and 6th month of postoperative follow-up, respectively. Eighteen (85.7%) and 16 patients (76.2%) completed both the ICIQ-SF and I-PSS questionnaires at the 3rd and 6th month of postoperative follow-up, respectively. Only 7 and 10 patients (33.3% and 47.6%, respectively) completed the IIEF-5 and FSFI at the 3rd month of postoperative follow-up. There was no significant difference in age, BMI, tumor location, neoadjuvant therapy, postoperative pathological results, and adjuvant therapy between the two groups. Our study did not identify any parameter that could suggest lower urinary tract dysfunction in both groups analyzed, either by evaluating maximum flow, postvoid residue and, mainly, by the results of detrusor pressure at maximum flow. On the other hand, the present study demonstrated better sexual function outcomes with robotic surgery in male patients as assessed by the IIEF-5 score. There was a slight advantage to robotic surgery at the 3-month follow-up (median score 18 for robotic versus 17 for laparoscopic). By 6 months, the difference became more pronounced in favor of the robotic group (median score 23 for robotic versus 15 for laparoscopic). Additionally, there was better sexual desire at 3 months in the robotic group according to the QLQ-C29 (median score 66.7 in the robotic group versus 16.6 in the laparoscopic group). The robotic approach for TME was associated with potentially better male sexual function than the laparoscopic approach. More randomized studies with a larger number of patients are necessary to confirm our findings.