Transurethral hot-water balloon thermoablation for benign prostatic hyperplasia: patient tolerance and pathologic findings

Abstract

Objectives. To determine the patient tolerance and thermal ablation pattern in human prostatic tissue after treatment with a hot water, catheter-based system. Methods. Twenty-seven men scheduled for surgery for symptomatic benign prostatic hyperplasia or adenocarcinoma of the prostate underwent water-induced thermotherapy. The patients were randomly assigned to one of four treatment groups. Lidocaine gel was the sole means of pain control. The patients and an observer recorded patient discomfort during therapy. A Foley catheter was left in place until surgery (n = 13) or successful voiding (n = 14). Prostates were subsequently enucleated or removed, whole mounted, and examined. Results. Patients reported mild treatment discomfort, the level of which did not correlate with the extent of necrosis, balloon diameter, or water temperature (all P >0.05). Distal penile burning was the most commonly reported discomfort. All 14 patients successfully voided within 12 days of treatment. Prostates were enucleated (n = 24) or removed (n = 3) at a mean of 27 days (range 4 to 120) after thermotherapy, except for a single adenectomy 17 months after therapy. Pathologic findings included periurethral hemorrhagic necrosis, with focal or extensive urothelial denudation and mild inflammation. The mean maximal depth of necrosis from the urethral lumen was 7, 9, 10.33, and 11 mm in groups 1, 2, 3, and 4, respectively. The extent of necrosis was similar in all groups ( P = 0.11), regardless of the water temperature; conversely, the balloon diameter correlated with the depth of necrosis ( P = 0.024). Conclusions. This system of tissue ablation appears to be well tolerated, and it produced consistent pathologic results.