Bipolar versus monopolar technique for palliative transurethral prostate resection Bipolar resection of the prostate is based on a slightly different technological concept. By incorporating both the active and return poles on the same electrode [3], a conductive fluid medium (normal saline) instead of the conventional nonconductive irrigation fluid (glycine, sorbitol, and mannitol) can be used. The peri- and postoperative morbidity as well as the final outcome of bipolar resections with the Gyrus PlasmaKinetic and the Olympus TURIS systems was evaluated in several randomized controlled trials [4]. All trials supported the conclusion that bipolar technology provides a similar clinical efficacy compared to that of monopolar transurethral resection of the prostate [4]. The lower risk of peri- and postoperative morbidity regarding TUR syndrome and clot retention however does favour the bipolar technology [5]. We retrospectively evaluated this peri- and postoperative morbidity using both techniques in patients with urinary obstruction due to prostate cancer. Material and methods A retrospective analysis of 75 endoscopic procedures in 70 patients for relief of obstructive voiding difficulties and retention due to prostate cancer was performed at a single university institution between August 2005 and March 2009. Outpatient records, inpatient charts, and operative reports were reviewed. Electrolyte changes, postoperative complications, and clinical outcome were selected as data points of special interest in order to compare the two slightly different pieces of operative equipment, i.e. the monopolar technique (TURP) and bipolar technique (TURIS). All palliative endoscopic resections were performed by two staff urologists, both familiar with the two types of equipment. A standard Olympus resectoscope and an Olympus UES-40 SurgMaster electrical current generator were used for both techniques. Monopolar TURP was carried out with a standard 24 Fr resectoscope and standard loops using 175 W cutting power and 75 W coagulation power. Bipolar TURIS was performed using a 24 Fr resectoscope with the bipolar electrode set at 270 W for cutting and 75 W for coagulation. All procedures were performed with intermittent glycine 5% (monopolar TURP) or saline 0.9% (bipolar TURIS) irrigation using general or spinal anaesthesia. An average amount of 12 litres/procedure was used. Both urologists used the same resection technique. Palliative resection was defined as a limited resection to create a channel permitting better urinary flow. In contrast with standard endoscopic resection for BPH, resection to the depth of the prostatic capsule was not attempted. All resected tissue was weighed and submitted to the pathologist for review. At the end of the procedure, a 22 Fr 3-way Foley catheter with a closed drainage system was inserted. All patients were treated postoperatively with continuous saline bladder irrigation until bleeding ended. After discharge, patients were reassessed at three-month intervals. All statistical tests performed were two-sided and at the 5% level of performance. The two groups were compared using the independent T-test. The incidence of complications such as TUR syndrome, clot retention, and urinary retention were determined by Fisher’s exact test. The p-values obtained were similar to the χ2 test with continuity correction. SPSS version 17.0 was used to perform the tests. Results A total of 70 patients underwent 75 endoscopic procedures between August 2005 and March 2009. Their mean age was 76 ±9 years (range 61 to 93 years). The mean time from cancer diagnosis to endoscopic resection was 56.7 ±52.5 months (range 3 to 210 months). The initial oncological parameters are listed in Table I. In 68 of the 70 patients, the initial diagnosis of prostate cancer was made in our institution. T1 prostate cancer was found in 18%, T2 prostate cancer in 22%, T3 prostate cancer in 53%, and T4 prostate cancer in 7%. Regarding initial grading, 12% had well-differentiated, 50% moderately differentiated, and 38% poorly differentiated prostate cancer. Twenty-two of the 68 men had metastatic disease as documented by plain X-ray and bone scan at the time of diagnosis. Table I. Initial oncological parameters Variables Stage T1 T2 T3 T4 Grade 2-4 5-7 8-10 Bone metastases Monopolar TURP N (%) 6 (19) 5 (16) 19 (59) 2 (6) 4 (17) 12 (50) 8 (33) 11 (34) Bipolar TURIS N (%) 6 (17) 10 (28) 17 (47) 3 (8) 3 (9) 17 (50) 14 (41) 11 (31) Total N (%) 12 (18) 15 (22) 36 (53) 5 (7) 7 (12) 29 (50) 22 (38) 22 (32) TURP – transurethral resection of prostate, TURIS – transurethral resection of prostate in saline, N – number Arch Med Sci 5, October / 2010 781