High BMI, Aggressive Tumours and Long Console Time Are Independent Predictive Factors for Symptomatic Lymphocele Formation after Robot-Assisted Radical Prostatectomy and Pelvic Lymph Node Dissection.

INTRODUCTION: Lymphocele (LC) formation is a common complication which may cause severe symptoms after robot-assisted radical prostatovesiculectomy (RARP) with concomitant pelvic lymph node dissection (PLND). Compared to open radical prostatectomy, the amount of data on potential risk factors for LC formation is still limited. The aim of the present study was to identify risk factors for symptomatic LC formation (sLC) after RARP with PLND. METHODS: We used the data of a prospective multicentre series of 232 RARP patients which were treated between March 2017 and December 2017. The primary endpoint was the presence of sLC within 90 days. Asymptomatic LC (aLC) formation was also recorded. We evaluated clinical, perioperative, and histopathological criteria and compared their distribution in patients with and without post-operative sLC. Uni- and multivariable logistic regression analyses (MVAs) were performed to identify potential predictors for LC formation. Regarding the influence of patients' BMI, 2 models were calculated: BMI continuously (model 1) and BMI dichotomized with cut-off 30 kg/m2 (WHO definition, model 2). RESULTS: Post-operative sLC was present in 21 patients (9.1%), while aLC was detected in 49 patients (21.1%) 90 days after RARP with PLND. Patients with sLC showed higher median baseline PSA levels (9.8 vs. 8.1 ng/mL), higher prevalence of obesity (BMI >30; 42.9 vs. 19.9%), and longer median console time (180 vs. 165 min) compared to patients without sLC. On MVA higher BMI {model 1: OR 1.145 (confidence interval [CI] 1.025-1.278); model 2: OR 2.761 (1.045-7.296)}, longer console time (model 1: OR 1.013 [1.005-1.021]; model 2: OR 1.013 [1.005-1.020]) and an ISUP grade ≥3 (model 1: OR 3.247 [1.182-8.917]; model 2: OR 2.791 [1.050-7.423]) were identified as independent predictors for sLC development. CONCLUSION: Patients with aggressive tumours and higher BMI should be informed about a potentially increased risk for sLC formation. In case of a long console time, a close and regular follow-up should be considered to check for LC development.