Michielsen DP, Coomans D, Braeckman JG & Umbrain V. “Bipolar transurethral resection in saline: The solution to avoid hyponatraemia and transurethral resection syndrome.” Scandinavian Journal of Urology and Nephrology. 2010, 44: 228-235. 

OBJECTIVES: To compare serum sodium changes and the incidence of transurethral resection (TUR) syndrome after monopolar transurethral resection of the prostate (TURP) and bipolar transurethral resection in saline (TURIS) for symptomatic benign prostatic hyperplasia.

RESULTS: Over 56 months, 265 patients underwent a conventional monopolar TURP and 285 patients had a bipolar TURIS (Olympus). Patient profiles regarding age, operation time, resection weight and resection speed were similar in both groups. A drop in sodium of 2.5 mmol/l was measured in the conventional monopolar resection group. The decline of 1.5 mmol/l in the bipolar group, although smaller, was still statistically significant (p = 0.001). With longer operation times (> 1 h) the difference between the groups became more important (p < 0.001). Two clinical TUR syndromes were observed in the monopolar group, while none occurred in the bipolar group. 

CONCLUSION: Bipolar TURP in saline is a safe technique and obviates the risk of TUR syndrome. Repeated serum analysis of electrolytes after TURIS can be omitted.
Link to study: http://www.tandfonline.com/doi/abs/10.3109/00365591003720275