Impact of Pelvic Lymph Node Dissection and Its Extent on Perioperative Morbidity in Patients Undergoing Radical Prostatectomy for Prostate Cancer: A Comprehensive Systematic Review and Meta-analysis

CONTEXT: Pelvic lymph node dissection (PLND) yields the most accurate staging in patients undergoing radical prostatectomy (RP) for prostate cancer (PCa), although it can be associated with morbidity. OBJECTIVE: To systematically evaluate the impact of PLND extent on perioperative morbidity in patients undergoing RP. A new PLND-related complication assessment tool is proposed. EVIDENCE ACQUISITION: A systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) was conducted. MEDLINE/PubMed, Scopus, Embase and Web of Science databases were searched to yield studies discussing perioperative complications following RP and PLND. The extent of PLND was classified according to the European Association of Urology PCa guidelines. Studies were categorized according to the extent of PLND. Intra- and postoperative complications were classified as "strongly," "likely," or "unlikely" related to PLND. Anatomical site of perioperative complications was recorded. A cumulative meta-analysis of comparative studies was conducted using Review Manager 5.3 (Cochrane Collaboration, Oxford, UK). EVIDENCE SYNTHESIS: Our search generated 3645 papers, with 176 studies meeting the inclusion criteria. Details of 77 303 patients were analyzed. Of these studies, 84 (47.7%), combining data on 28 428 patients, described intraoperative complications as an outcome of interest. Overall, 534 (1.8%) patients reported one or more intraoperative complications. Postoperative complications were reported in 151 (85.7%) studies, combining data on 73 629 patients. Overall, 10 401 (14.1%) patients reported one or more postoperative complication. The most reported postoperative complication strongly related to PLND was lymphocele (90.6%). The pooled meta-analysis revealed that RP + limited PLND/standard PLND had a significantly decreased risk of experiencing any intraoperative complication (risk ratio [RR]: 0.55; p =  0.01) and postoperative complication strongly related to PLND (RR: 0.46; p =  <0.00001), particularly for lymphocele formation (RR: 0.52; p =  0.0003) and thromboembolic events (RR: 0.59; p =  0.008), when compared with extended/superextended PLND. The extent of PLND was confirmed to be an independent predictor of lymphocele formation (RR: 1.77; p <  0.00001). CONCLUSIONS: The perioperative morbidity of PLND in patients undergoing RP and PLND for PCa significantly correlates with the extent of PLND. More standardized reporting of intra- and postoperative complications is needed to better estimate the direct impact of PLND extent on perioperative morbidity. PATIENT SUMMARY: Pelvic lymph node dissection (PLND) is the most accurate method for staging in patients undergoing radical prostatectomy for prostate cancer, although it can be associated with complications. This study aims to systematically evaluate the impact of PLND extent on perioperative complications in these patients. We found that intra- and postoperative complications correlate significantly with the extent of PLND. A more rigorous assessment and thorough reporting of perioperative complications are recommended.