title: Sildenafil non-responders: haemodynamic and morphometric studies.
abstract: OBJECTIVE
  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 microg PgE1) 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.
authors.affiliation: Department of Urology and Pathology, C.H.U. de Charleroi, Charleroi and Hôpital Erasme, 808 route de Lennik, 1070 Brussels, Belgium. dr.wespes@skynet.be
authors.forename: Eric
authors.initials: E
authors.lastname: Wespes
authors.forename: Adham
authors.initials: A
authors.lastname: Rammal
authors.forename: Christian
authors.initials: C
authors.lastname: Garbar
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D000328:Adult; D000368:Aged; D001706:Biopsy; D001783:Blood Flow Velocity / Q000187:drug effects / Q000502:physiology*; D007172:Erectile Dysfunction / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D010410:Penile Erection / Q000187:drug effects / Q000502:physiology; D010413:Penis / Q000000981:diagnostic imaging / Q000187:drug effects / Q000503:physiopathology*; D010879:Piperazines / Q000627:therapeutic use*; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones; D013739:Testosterone / Q000097:blood; D017211:Treatment Failure; D018608:Ultrasonography, Doppler; D014665:Vasodilator Agents / Q000627:therapeutic use*
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014665:Vasodilator Agents; D013739:Testosterone; D000068677:Sildenafil Citrate; D015106:3',5'-Cyclic-GMP Phosphodiesterases