EVALUATION OF A NO-NEEDLE PENILE INJECTOR - A PRELIMINARY-STUDY EVALUATING TISSUE PENETRATION AND ITS HEMODYNAMIC CONSEQUENCES IN THE RAT

Objectives, Intracavernous needle injection is an effective delivery m ethod for pharmacotherapy of erectile dysfunction. Needle phobia, pain , and concern about local tissue injury have stimulated the search for new, less invasive means of inducing penile erection. In this prelimi nary communication, we evaluate a jet injector as an alternative to ne edle injection for intracavernous delivery of vasoactive drugs. Method s. Jet injection was evaluated in three groups of rats receiving eithe r India ink, saline, or papaverine into the penis. The ability of the jet injection to penetrate through the tunica albuginea and deliver li quid to the corpora cavernosa smooth muscle was assessed by the degree of staining within the corpus cavernosum (ink group), histologic chan ge (saline group), and rise in intracavernous pressure (papaverine gro up), Erectile capacity following cavernous nerve electric stimulation was compared before and 1 hour after injection of saline or papaverine . Results, Ink traversed the skin and tunica albuginea with extensive deposition noted within the cavernous spaces. Varying degrees of subcu taneous hemorrhage were seen with saline jet injection; however, the c orpus cavernous smooth muscles showed no evidence of injury, Jet injec tion of papaverine 3250 mu g significantly increased cavernous pressur e (59.4 +/- 4.6 cm H2O) compared with saline injection (2.8 +/- 1.3 cm H2O). Conclusions, We conclude that acute jet injection is an effecti ve method for intracavernous delivery of drugs, Long-term effects shou ld be evaluated prior to clinical use. (C) 1997, Elsevier Science Inc. All rights reserved.