The Impact of Retro-apical Urethral Dissection Approach Technique on Positive Surgical Margins in Robotic-assisted Laparoscopic Radical Prostatectomy: A Study in Thailand

Objective: Among the various postoperative outcomes following robotic-assisted laparoscopic radical prostatectomy (RARP), positive surgical margins (PSMs) are a significant prognostic factor associated with biochemical recurrence (BCR). Many surgical techniques are available for RARP; however, the technique proposed in this study may improve surgical outcomes. This study aims to evaluate the incidence of post-operative PSMs in patients diagnosed with clinically localized prostate cancer at Siriraj Hospital using the retro-apical urethral dissection approach with a 30-degree-lens flip-up technique. Materials and Methods: A retrospective review of 2,114 consecutive patients who underwent RARP with the conventional technique was conducted using Siriraj Hospital’s database, from January 2007 to June 2022. Propensity score matching was employed to select a group of 284 men from the total cohort of 2,114 patients who underwent conventional radical prostatectomy (Group 1) for comparison against another group of 284 patients who underwent the retro-apical dissection technique (Group 2). The incidence of PSMs was then evaluated in each group. Results: Of the 568 patients, PSMs were observed in 219 patients. The overall incidence of PSMs decreased from 128 cases (45.1%) in Group 1 to 91 cases (32.0%) in Group 2 (p-value <0.01). Similar results were seen in the subgroup of patients with pT2 staging who had PSMs (52 cases vs 24 cases, p-value <0.01). PSMs occurred mostly at the apex with a total of 112 cases (52.1%). Conclusion: The retro-apical urethral dissection approach with a 30-degree-lens flip-up technique is associated with a lower risk of overall PSMs and the trend of apical PSMs, indicating its clinical significance.