title: Phentolamine re-dosing during penile dynamic colour Doppler ultrasound: a practical method to abolish a false diagnosis of venous leakage in patients with erectile dysfunction.
abstract: Increased sympathetic tone may cause an equivocal response to a prostaglandin E1 (PGE1) penile Doppler ultrasound (US) examination interpreted as a venous leak. We evaluated the US parameters and erectile response to the addition of phentolamine to a PGE1 penile Doppler US examination to ascertain whether addition of phentolamine would abolish a suboptimal response. 32 patients (median age 29 years, range 17-70 years) with either a previous Doppler US pattern of venous leakage or a clinical suspicion of venogenic impotence, underwent Doppler US after a total dose of 20 microg of PGE1. Peak systolic velocity (PSV), end diastolic velocity (EDV) and grade of erection were documented. If erectile response was suboptimal irrespective of the EDV measurement, 2 mg-intracavernosal phentolamine was administered and measurements repeated. Six patients had a normal erectile response, the remaining 26 received phentolamine. A significant increase in PSV between baseline and 20 microg PGE1 (p<0.001) was observed in all cases. Following phentolamine there was a significant increase in grade of erection (p=0.0001) and a significant reduction in the EDV (p=0.0001). A reduction of the EDV to below 0.0 cm s(-1) was observed in 16 patients. Four patients with EDV <5.0 cm s(-1) but >0.0 cm s(-1) had improved erectile response following phentolamine while six showed persistent EDV elevation >5 cm s(-1). No priapism was documented. It is essential to ensure cavernosal relaxation using phentolamine before a Doppler US diagnosis of venous leak is made. This two-stage assessment will allow this to be done efficiently and with a low risk of priapism.
authors.affiliation: Departments of Urology and Radiology, King's College Hospital, Denmark Hill, London SE5 9RS, UK.
authors.forename: P
authors.initials: P
authors.lastname: Gontero
authors.forename: S
authors.initials: S
authors.lastname: Sriprasad
authors.forename: C J
authors.initials: CJ
authors.lastname: Wilkins
authors.forename: N
authors.initials: N
authors.lastname: Donaldson
authors.forename: G H
authors.initials: GH
authors.lastname: Muir
authors.forename: P S
authors.initials: PS
authors.lastname: Sidhu
mesh_terms: D000293:Adolescent; D000317:Adrenergic alpha-Antagonists / Q000008:administration & dosage*; D000328:Adult; D000368:Aged; D000527:Alprostadil; D001794:Blood Pressure / Q000187:drug effects; D003951:Diagnostic Errors / Q000517:prevention & control*; D004359:Drug Therapy, Combination; D006801:Humans; D018783:Impotence, Vasculogenic / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009126:Muscle Relaxation / Q000187:drug effects; D010413:Penis / Q000098:blood supply* / Q000648:ultrastructure; D010646:Phentolamine / Q000008:administration & dosage*; D012039:Regional Blood Flow / Q000187:drug effects; D018615:Ultrasonography, Doppler, Color / Q000379:methods / Q000592:standards*; D014665:Vasodilator Agents
chemical_list: D000317:Adrenergic alpha-Antagonists; D014665:Vasodilator Agents; D000527:Alprostadil; D010646:Phentolamine