Transurethral prostatic resection or laser therapy for men with acute urinary retention: The CLasP randomized trial

Purpose: Transurethral resection of the prostate is the standard operation for acute urinary retention, although laser prostatectomy is reportedly eff ective and safe. The ClasP (conservative management, laser, transurethral r esection of the prostate) study compared transurethral prostatic resection and noncontact needymium (Nd):YAG visual laser assisted prostatectomy for t reatment of acute urinary retention. Materials and Methods: This study was a multicenter randomized controlled t rial, analyses were by intention to treat and followup was at 7.5 months af ter randomization. Primary outcomes were treatment failure, and included In ternational Prostate Symptom Score, International Prostate Symptom Score qu ality of life score, residual urine and flow rate. Secondary outcomes inclu ded complications, and duration of catheterization and hospitalization. Results: A fetal of 148 men were randomized to transurethral prostatic rese ction (74) and laser (74). There were fewer treatment failures after prosta tic resection (p = 0.008) and fewer men after resect-ion required secondary surgery for poor results (1 versus 7, p = 0.029). Maximum flow rates after transurethral prostatic resection were better than after laser (mean diffe rence 4.4 ml. per second). Comparison of symptom and quality of life scores demonstrated that any clinically significant advantage for laser could be ruled out. Patients stayed a mean of 2 extra days in the hospital after res ection. The duration of catheterization was greater after laser but signifi cantly fewer major treatment complications were found with laser therapy. Conclusions: Transurethral prostatic resect-ion was more effective, resulte d in fewer failures than laser treatment and remains the procedure of choic e for men with acute urinary retention.