Higher nodal yield with robot-assisted pelvic lymph node dissection for bladder cancer compared to laparoscopic dissection: implications for more accurate staging.

Objective: To compare the lymph node (LN) yield and adequacy of laparoscopic pelvic lymph node dissection (L-PLND) and robot-assisted PLND (R-PLND), as PLND is a fundamental component of radical cystectomy (RC) for bladder cancer (BCa), where a positive status is the most powerful predictor of disease recurrence and survival.

Methods: We retrospectively reviewed patients undergoing RC with PLND for BCa from January 2007 to July 2019 and grouped them in to L- and R-PLND. Until 2011, patients underwent a standard PLND (S-PLND) with the cranial limit as bifurcation of common iliac artery. Since 2012, an extended PLND (E-PLND) up to aortic bifurcation has been performed. An adequate S- and E-PLND were defined as those that yielded at least 10 and 16 LNs, respectively. The groups were compared for LN yield and adequacy of PLND.

Results: During the study period, 305 patients underwent minimally invasive RC in our centre, of which 274 (89.8%) underwent a concomitant PLND (98 L-PLND, 176 R-PLND). R-PLND resulted in a significantly greater median LN yield compared to L-PLND, both in the S-PLND (16 vs 11, P < 0.001) and the E-PLND (19 vs 14, P < 0.001) eras. Also, a significantly higher proportion of patients in the R-PLND group had an adequate PLND compared to the L-PLND group. Surgical approach to PLND (R- vs L-PLND) was the only variable that was significantly associated with an adequate PLND on both univariable (odds ratio [OR] 1.860, 95% confidence interval [CI] 1.114-3.105; P = 0.01) and multivariable (OR 2.109, 95% CI 1.222-3.641; P = 0.007) analyses.

Conclusions: R-PLND leads to a higher LN yield and a greater probability of an adequate PLND compared to L-PLND for both standard and extended templates. Therefore, the robot-assisted approach would lead to more accurate staging following RC with PLND.