Sildenafil Non-Responders: Haemodynamic and Morphometric Studies

Abstract

Objectives: Most of the available data on efficacy for sildenafil are based on a questionnaire and erectile dysfunction (ED) is classified with minor or severe organic factors. To better select sildenafil responders and non-responders, we have conducted a haemodynamic and morphometric study in sildenafil non-responders. Methods: Thirty patients with ED aged from 28 to 74 years-old did not respond to 8 attempts of 100 mg of sildenafil. They underwent hormonal measurements, intracavernous injection (ICI 20 μg PgE 1) followed by Doppler examination and cavernosometry. A penile biopsy was performed under local anesthesia. A quantification of the cavernous smooth muscle (SMC) was performed with a computerized image analysis after staining with actin anti-actin. Results: Twenty-eight patients had a very poor ICI response. Five patients were diabetic and 2 had low testosterone level. Eight patients had arterial lesions, 15 had venous leak and 5 both lesions. They all had reduction of SMC (<35%). No biological and vascular abnormality was observed in two patients. They had a percentage of SMC of 38% and 42%. No complication was observed with the penile biopsy. Conclusions: Severe vascular lesions and atrophy of SMC are mainly observed in sildenafil non-responders. The age, diabetes and low testosterone level seem not to be related with the failures.