Influence of Body Mass Index, Surgical Approach and Lymphadenectomy on the Development of Symptomatic Lymphoceles after Radical Prostatectomy

Purpose: Identification of factors influencing lymphocele formation requiring intervention after radical prostatectomy. Methods: 302 patients undergoing radical retropubic prostatectomy (RRP, n = 174) or transperitoneal robot-assisted laparoscopic prostatectomy (RALP, n = 128) by the same surgeon were retrospectively reviewed. Incidence of symptomatic lymphoceles (SLC) was compared with clinical and pathological data (contingency analyses, Wilcoxon-Kruskal-Wallis test). Results: Sixteen patients (5.3%) developed SLC. SLC occurred significantly more frequently after RRP compared to RALP (8.0 vs. 0.8%, p = 0.0008). Patients with SLC had more lymph nodes (LN) removed median (17 vs. 13, p = 0.009) and a significantly lower BMI (median 24.4 vs. 26.4, p = 0.0008). Presence of LN metastases (n = 18 patients, 6.0%) showed no statistical impact on SLC. In a multivariate analysis surgical method, the number of resected LN and the BMI remained independent predictors of SLC formation. Conclusions: The lower incidence of SLC after RALP compared to RRP probably results from peritoneal drainage of lymphatic fluid. The correlation of removed LN and SLC might be explained by increased injury of lymphatic vessels during more extended LN dissection. Why patients with lower BMI are more prone to develop SLC still remains unclear. However, early postoperative mobilization in nonobese patients might be a contributing factor.