Value of color Doppler sonography in the diagnosis of venous impotence

Significance of phentolamine redosing during prostaglandin E1 penile color Doppler ultrasonography in diagnosis of vascular erectile dysfunction

Recently, it was reported that phentolamine redosing during penile duplex can abolish a false diagnosis of venous leakage in patients with impotence. The aim of this study is to identify any useful role of phentolamine redosing in diagnosis of venogenic impotence. Sixty-seven consecutive patients complaining of weak erection for at least 6 months were included in this study. Penile color Doppler ultrasound (CDU) was performed using a 7.5 MHz linear array transducer with a color flow mapping capability. Following intracavernous injection of 20 microg prostaglandin E1 (PGE1), all patients with persistent end diastolic velocity (EDV) >5 cm/sec with an erectile response of E3 or lower, 20 min after intracavernosal injection of PGE1, were asked to revisit our clinic for a second CDU, 2 weeks later. During initial CDU examination, all 67 patients experienced poor response to 20 microg PGE1 with their average peak systolic velocity (PSV) and EDV being 42.8 and 6.6 cm/sec, respectively. The second CDU examination had similar results to the first one. Addition of 2 mg phentolamine did not significantly change the PSV and EDV of cavernosal arteries in any of the 67 patients. In conclusion, addition of intracavernous phentolamine during PGE1 CDU examination carries no advantage over the use of PGE1 alone regarding cavernosal artery response in patients with suspected venogenic EDV.

Increased estradiol levels in venous occlusive disorder: a possible functional mechanism of venous leakage

Venous insufficiency of the corpora cavernosa is the second most common cause of erectile dysfunction (ED). A functional insufficiency of the venous system has been hypothesised, but the cause is still unclear. To evaluate a possible endocrine mechanism, we have studied hormone profile in a group of nine patients with pure venous-leakage (VL) compared with a control group of 15 patients with ED of different origin. Prolactin, testosterone and gonadotropin levels did not differ among the two groups, while estradiol (E2) plasma concentration was significantly higher in VL patients compared to controls. Our data support the hypothesis that the steroid environment, in particular estradiol level, can influence venous vascular tone (via VEGF or NO), thus affecting venous leakage dysfunction. This point can explain a possible link between the high estradiol levels and a functional insufficiency of the venous system in ED.

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

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.

Clinical efficacy of Apomorphine SL in erectile dysfunction of diabetic men

Although subgroup analyses from large randomised premarketing studies have shown that Apomorphine SL enhances the percentage of erections firm enough for sexual intercourse in diabetic men, the clinical role of the drug in this patient population remains to be elucidated. The aim of the present study was to assess the efficacy of Apomorphine SL in diabetic males with erectile dysfunction (ED) and to identify factors predicting those who may benefit from the treatment. A total of 130 diabetic patients were randomised to receive either four tablets of 3 mg Apomorphine or a matching placebo. Assessments of efficacy comprised the erectile function (EF) domain of the International Index of Erectile Function (IIEF) and the one-item global efficacy question (GEQ). Patients with both a positive response to the GEQ and an improvement of at least 5 points in the EF domain of the IIEF were considered responders and subanalysed by several parameters indicative of the severity of both ED and diabetes. Response rate was 17% after placebo and 22% after Apomorphine SL. The EF domain of the IIEF and both questions 3 and 4 scores did not significantly improve in either of the two arms over the baseline. A younger age and a lower Hb1Ac were significantly linked to the status of responder in the Apomorphine arm. Apomorphine SL failed to show a statistically significant benefit over a placebo, but 22% of patients had a clinically significant erectile response. These figures seem to suggest that the drug has a limited use for ED diabetic patients.

Congruence between veno-occlusive parameters during dynamic infusion cavernosometry: assessing the need for cavernosography

While dynamic infusion cavernosometry (DIC) is being performed with increasing rarity, some centers continue to use this investigation modality. Cavernosography may be utilized to identify the location of patent venous channels in men with venous leak. In an era when venous ligation surgery is being performed with less frequency, the role of cavernosography has been questioned. This study was conducted to define the congruence between the three parameters (flow-to-maintain (FTM), pressure decay (PD) and cavernosography) used in the diagnosis of venous leak during DIC. Established values for the three parameters were utilized and the diagnosis of venous leak was based upon the FTM measurement. All studies were performed using a vasoactive agent-redosing schedule. Cavernosography was conducted using a nonionic contrast agent at an intracorporal pressure of 90 mmHg. In patients with an elevated FTM value, 24% had a normal PD recorded, all of whom had FTM values <10 ml/min. The Pearson correlation coefficient for the relationship between FTM and PD was 0.58 (P=0.025). In all, 36 patients (54%) had an abnormal cavernosogram (CG). All patients who had positive findings on CG had elevated FTM values. On the other hand, 46% of patients with abnormal FTM values had a normal CG. This analysis indicates that almost one-half of men with venous leak diagnosed at the time of DIC based on FTM measurement will fail to have any veins visualized on cavernosography. These data further undermine the value of cavernosography, particularly in men with low-grade venous leak.

Intracavernosal vascular endothelial growth factor (VEGF) injection and adeno-associated virus-mediated VEGF gene therapy prevent and reverse venogenic erectile dysfunction in rats

Penile veno-occlusive dysfunction (venogenic erectile dysfunction) is a common cause of erectile dysfunction (ED). We investigated whether vascular endothelial growth factor (VEGF) can be used to prevent and reverse venogenic ED in a rat model. Pharmacological cavernosometry was developed and validated using adult male rats with either arteriogenic or venogenic ED. Castrated animals were treated with intracavernous VEGF as either a recombinant protein (C+VEGF) or adeno-associated virus (AAV)-mediated VEGF gene therapy (C+VEGF gene) in an attempt to prevent the development of venogenic ED. Other animal groups received testosterone replacement (C+testosterone) or intracavernous AAV-LacZ gene (C+LacZ). Animals with documented venogenic ED were treated with intracavernous VEGF in an attempt to reverse their ED. Functional analysis (pharmacological infusion cavernosometry) was performed following treatment. Penile specimens were harvested for immunohistochemistry and electron microscopic evaluation. Castrated rats showed a decrease in papaverine-induced intracavernous pressure and an increase in maintenance and drop rates during pharmacological cavernosometry. These changes were prevented by systemic testosterone and intracavernous VEGF or AAV-VEGF therapy. Moreover, intracavernous VEGF was able to reverse the venogenic ED produced by castration. The quantity of penile smooth muscle detected by alpha actin staining decreased after castration but not in the C+T, C+VEGF, or C+VEGF gene groups. Transmission electron microscopy revealed atrophy of penile smooth muscle cells and nerves in the castrated rats. In VEGF-treated rats, regeneration of smooth muscle and nerves as well as endothelial cell hypertrophy and hyperplasia were the prominent features. In our animal model, systemic testosterone replacement or intracavernous VEGF (protein and VEGF gene) prevented the veno-occlusive dysfunction in castrated animals. In rats with established venous leakage, VEGF treatment reversed the cavernosometric findings of leakage. Intracavernous injection of either VEGF protein or VEGF gene may be a preferred therapy to preserve erectile function in patients in whom testosterone therapy is contraindicated.