Ablation of canine prostate using transurethral intraprostatic absolute ethanol injection

Despite extensive research involving numerous treatments for benign prostatic hyperplasia (BPH), the ideal modality has yet to be discovered. This study evaluated chemoablation of the prostate using transurethral intraprostatic absolute ethanol injection (AEI) in an in vivo canine model.

Eight mongrel dogs, 7 to 10 years old, underwent transurethral intraprostatic AEI with various ethanol volumes (10 to 26 mL/animal, mean 19.9). Injection was performed using a 20-gauge, passive deflection, hollow-core needle, introduced cystoscopically by way of a perineal urethrotomy. Oral antibiotics were administered perioperatively. Blood alcohol levels were determined. The canines were kept alive for 1 hour (n = 1), 7 days (n = 2), and 21 days (n = 5) after the treatment. The dogs were observed twice daily for a minimum of 30 minutes to determine continence. At least one spontaneous voiding was recorded at each observation. Before the dogs were sacrificed, the prostate and surrounding tissues were harvested, with gross and microscopic examination performed by a single pathologist.

Seven and 21 days after AEI, the prostates demonstrated necrosis and cavity formation. Deep injection resulted in cavity formation in a subcapsular location. Superficial injection resulted in cavity formation that was confluent with the urethra and resulted in a widened urethral lumen. No complications directly related to AEI were seen, and systemic absorption of ethanol was minimal.

AEI can effectively ablate prostatic tissue in canines with minimal systemic absorption. No disruption of the prostatic capsule or injury to the bladder urothelium and urethral sphincter was identified. Human studies of intraprostatic AEI for BPH adenomatous tissue chemoablation are ongoing at our institution.