Incidence of lymphoceles after robot-assisted pelvic lymph node dissection.

Objective: • To determine the incidence and predictive factors of lymphocele formation in patients undergoing pelvic lymph node dissection (PLND) during robot-assisted radical prostatectomy (RARP).

Patients And Methods: • Between April and December 2008, 76 patients underwent PLND during RARP for ≥cT2c, prostate-specific antigen level ≥10, Gleason score ≥7 prostate cancer. • All patients were prospectively followed up with pelvic computed tomography 6-12 weeks after the procedure. • All patients received s.c. heparin preoperatively and postoperatively. PLND was limited to zones 1 and 2 as defined by Studer. • Plasma-kinetic bipolar forceps were used for haemostasis during PLND.

Results: • At a mean follow-up of 10.8 weeks, 51% (39/76) of patients had developed a lymphocele. Of these 39 lymphoceles 32 (82%) were unilateral and seven (18%) were bilateral. • The mean (range) lymphocele size was 4.3 × 3.2 (1.5-12.3) cm; 41% of lymphoceles were <4 cm, 53.9% were 4-10 cm, and 5.1% were >10 cm in diameter. Six of the 39 lymphoceles (15.4%) were clinically symptomatic. The symptoms were as follows: pelvic pressure in five patients, abdominal distension with ileus in three patients, leg pain/weakness in one patient and costovertebral tenderness in one patient. Two lymphoceles required intervention. • On the logistic regression model the presence of nodal metastases, tumour volume in the prostate specimen and extracapsular extension (ECE) were independent risk factors for the development of a lymphocele. • There was no correlation between estimated blood loss, body mass index, pathological Gleason score or number nodes dissected and the presence of lymphocele.

Conclusions: • The incidence of lymphoceles was higher than anticipated given the believed protective effect of the transperitoneal approach against lymphocele formation. • The risk of lymphocele seemed to increase linearly with the presence of more extensive disease, particularly ECE and nodal involvement. • The benefit of PLND during RARP should be weighed against the elevated risk of lymphocele formation and its potential complications.