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 x 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.