Measurement of penile intracavernous pressure with a skin fold caliper.

Objective: We report the use of the skin fold caliper as a simple, noninvasive device for the measurement of penile intracavernous pressure (ICP).

Methods: A commercial skin fold caliper (Lange type) was used to evaluate erections produced by intracavernous injections of prostaglandin E(1) in 43 patients and to compare ICP with radial rigidity estimation in 13 impotent men undergoing cavernosometry. Calculation of the rigidity index using the skin fold caliper was based on the girth change of the penis shaft when the caliper's jaws exerted a constant pressure of 10 g/mm(2).

Results: Measurements of radial rigidity at the base and the midshaft of the penis were closely correlated (r = 0.96). The overall correlation between ICP and the rigidity index (after plotting data on exponential and logarithmic axes, respectively) was good (r = 0.94). The accuracy of the estimated ICP was good at low values and diminished at higher levels.

Conclusion: The skin fold caliper can be used for accessible, inexpensive and reproducible single measurements of penile radial rigidity of erections obtained under erotic stimulation in a household environment and for estimates of penile ICP during diagnostic and therapeutic procedures in clinical practice.