Transrectal ultrasound-guided intraprostatic injection of absolute ethanolwith and without carmustine: A feasibility study in the canine model

Objectives. To develop a reliable intraprostatic injection technique and to define the local and systemic toxicity of intraprostatic injection of dehy drated ethanol with and without carmustine. Methods. Twenty-three random-source male canines were divided into a contro l group (n = 3), a dehydrated ethanol-alone group (group 1, n = 10), and a dehydrated ethanol-plus-carmustine group (group 2, n = 10). A reliable intr aprostatic injection technique was developed with the control animals. The optimal volume of dehydrated ethanol for intraprostatic injection and the l ocal tissue effects of dehydrated ethanol injection were defined with group 1. The local tissue effects of escalating doses of carmustine were defined with group 2. All animals were injected under general anesthesia using tra nsrectal ultrasound (TRUS) guidance. Fourteen days after injection, a repea ted TRUS of the prostate was done, the animals were killed, and the bladder , prostate, and periprostatic tissues were excised for pathologic examinati on. Results. Sonographic changes in the prostate 2 weeks after injection were p resent in all group 1 and 2 animals. All prostates had varying amounts of h emorrhagic and coagulative necrosis, which correlated with the TRUS finding s. There were no differentiating pathologic features between group 1 and gr oup 2 specimens. The relative amount of necrosis varied with the doses of d ehydrated ethanol and carmustine injected, but was not predictable on the b asis of the doses administered. Subclinical prostatic microabscesses were i dentified in 6 of 10 group 1 animals and 4 of 10 group 2 animals. Only grou p 2 animals had alterations in their blood chemistry results, all of which were self-limited. Two had white blood cell nadirs of less than 2000 5 days after injection. No animals developed incontinence, and there were no rect al injuries. Conclusions. Intraprostatic dehydrated ethanol and carmustine injections we re readily controllable under TRUS guidance and resulted in hemorrhagic and coagulative necrosis of prostatic tissue with minimal associated morbidity and no incontinence in the dog model. Hematologic changes observed in the animals that received carmustine were self-limiting. UROLOGY 53: 1245-1251, 1999. (C) 1999, Elsevier Science Inc. All rights reserved.