INTRACAVERNOUS PRESSURE RESPONSES TO PHYSICAL AND ELECTRICAL-STIMULATION OF THE CAVERNOUS NERVE IN RATS

Objectives. To better define the techniques of nerve-sparing prostate dissection that would result in preservation of erectile function, we characterize the effects of physical pressure on the prostate and cave rnous nerve, electrical stimulation of the cavernous nerve, and pharma cologic manipulations on intracavernous pressure (ICP) in normal and d iabetic rats. Methods. Fischer-34 rats, both normal and diabetic, unde rwent dissections that isolated the cavernous bodies and cavernous ner ves. Cavernous body pressures were characterized during surgical manip ulation, during electrical stimulation of the cavernous nerves, and fo llowing papaverine hydrochloride injection. Results. In normal rats, b aseline cavernous pressures ranged from 5 to 15 cm H2O (mean 12.29). I n diabetic rats, the baseline pressure was significantly lower (3 to 7 .5 cm H2O). Lateral nerve displacement caused ICP to rise to approxima tely 35 cm H2O in normal rats, but only to 20 cm H2O in diabetic rats. Electrostimulation resulted in cavernous pressure increases of 10-fol d from baseline in normal rats and sevenfold from baseline in diabetic rats. ICPs were not disturbed appreciably with nerve-sparing dissecti on techniques. Neurotomy resulted in declines in baseline cavernous pr essures in all rats. Electrostimulation of the distal end of a severed nerve resulted in pressure rises to 50% of those observed in rats wit h intact cavernous nerves. Intracavernous papaverine injection before or after nerve stimulation masked subsequent (expected) pressure chang es. Conclusions. A change in cavernous pressure is a sensitive indicat or of cavernous nerve manipulation. Both cavernous pressure measuremen ts and electrostimulation of cavernous nerves may aid surgeons during radical prostatectomy. (C) 1998, Elsevier Science inc. Ail rights rese rved.