Comparative Study between Corpus Cavernosum-Electromyography Findings and Electron Microscopy of Cavernosal Muscle Biopsies in Erectile Dysfunction Patients

Background: Biopsy and electrical activity recordings of the corpus cavernosum are 2 new diagnostic methods for the evaluation of impotent men. We evaluated the corpus cavernosum ultrastructure and electromyography (EMG) recordings from patients with erectile dysfunction.
Methods: Twenty erectile dysfunction patients with veno-occlusive dysfunction underwent a detailed history, physical examination, biochemical tests, hormonal analysis, injection of an intracavernous vasoactive agent (60 mg papaverine-HCI), color penile Doppler ultrasonography, cavernosometry/ cavernosography and corpus cavernosum electromyography (CC-EMG). Thirteen patients underwent total vein ligation and 7 had penile prosthesis implantations. Tissue samples were obtained during surgery from both corpora cavernosa and examined by transmission electron microscopy. Control corporal tissue samples were taken from 3 cadavers.
Results: In 15 patients, CC-EMG recordings were 15.6 ± 0.65 μV in the flaccid state, which decreased in 13 patients after papaverine (5.61 ± 0.25 μV; P < 0.001). Five patients with diabetes mellitus had low amplitudes in the flaccid state (5.26 ± 0.45 μV), which did not vary significantly after a papaverine injection (4.99 |pL 0.75 μV). The pathology of the corpus cavernosum biopsy specimens revealed a smooth muscle cell thickened basal membrane, dilated rough endoplasmic reticulum, and increased numbers of fibroblasts, but ultrastructurally normal endothelial cells lining the and sinusoids. There was no difference between samples from diabetic or nondiabetic patients, or from either side of the corpora cavernosa. The only pathologic change observed in the controls was mitochondrial swelling.
Conclusion: CC-EMG is less invasive and a valuable method in patients with erectile dysfunction, whereas no specific findings were observed from penile biopsy specimens.