Effect of intraurethral papaverine on penile erection in rats

OBJECTIVES: The aim of this study is to investigate erectile response to intraurethral administration of papaverine in rats. MATERIAL AND METHODS: Male Sprague-Dawley rats were used in this study. Under urethane anesthesia, penis was exposed and intracavernous pressure (ICP) was recorded through a 23-gauge needle, which was inserted into right corpus cavernosum. Effects of intraurethral application of incremental doses of 0.2 ml papaverine gel (4-17.5 mg) on intracavernosal pressure were observed and compared with those of 0.4 mg papaverine applied into corpus cavernosum. Mean arterial blood pressure (MABP) and heart rate were also monitored. RESULTS: The mean basal ICP was 8.9 +/- 1.8 mm Hg. Intraurethral administration of papaverine did not increase ICP at any doses used in this study. After intracavernous injection of papaverine (0.4 mg), a significant increase in the ICP occurred from resting (8.9 +/- 1.8 mm Hg) to a peak at 57.5 +/- 9.9 mm Hg and persisted for 22.3 +/- 6.7 minutes (p < 0.05). The latter application significantly decreased MABP (22.3 +/- 3.1 mm Hg; p < 0.05). CONCLUSIONS: Intraurethral administration of papaverine does not seem to be an alternative to other erectile dysfunction treatment modalities. However, further studies on animals are necessary at higher concentrations or in combination with other mucosal enhancers to increase the effect of intraurethral administration of papaverine.     

Prostaglandin E1 in erectile dysfunction

Of 447 presenting with erectile dysfunction, 322 (72%) responded to intracavernous injection of PGE1 with erections that were adequate for sexual intercourse. A multidisciplinary comparative study of PGE1 and other vasoactive drugs, e.g., papaverine or the combination of papaverine and phentolamine, was performed in 249 patients. Whereas 180 of the 249 patients (72.3%) showed adequate erections after 10 or 20 micrograms PGE1, only 79 of them (31.3%) did so after papaverine. A further 72 of the 249 patients (29%) had adequate erections after papaverine/phentolamine; thus, a total of 151 of 249 patients (60.3%) developed good erections after papaverine/phentolamine. Whereas after PGE1 no patients at all suffered from priapism lasting more than 6 h, this occurred in 13 of 249 patients (5.2%) after papaverine or papaverine/phentolamine. After intracavernous injection of PGE1, 9.4% of the patients complained of uncomfortable penile sensations during erection interfering with sexual intercourse. Since the initial study, 60 patients have been instructed in self-injection therapy and a further 45 patients obtain intracavernous PGE1 injections periodically, with very promising results. In vitro studies of cavernosal tissue samples obtained from potent men with penile deviations showed both the excellent relaxation of the smooth muscles of cavernous bodies by PGE1 and the antiadrenergic effect of the drug.     

多普勒超声技术动态观察血管性勃起功能障碍患者阴茎血流动力学的变化

目的动态观察多普勒超声技术配合阴茎海绵体注射在血管性勃起功能障碍患者诊断中的价值。方法120例疑血管性ED患者在阴茎注射PGE1后5min、10min和20min应用多普勒超声技术测量阴茎血流动力学变化,指标包括:收缩期峰值流速(PSV)、舒张末期峰值流速(EDV)、血流阻力指数(RI)。另100例心因性ED设为对照组。第一次注射后勃起不佳的患者3d后增加PGE1剂量重新检测。结果120例患者可以观察到明显的血流动力学变化,其中有动脉性ED者34例,静脉性ED 55例,混合血管性31例。ICI后不同时间的多普勒测量其血流动力学变化有一定差异。结论多普勒超声技术诊断血管性勃起功能障碍有一定意义。阴茎海绵体注射药物后须动态观察阴茎血流动力学的变化。     

Penile duplex sonography in the diagnosis of venogenic impotence

This study tested the hypothesis that measurements of cavernous arterial diastolic velocity and resistance index could provide a quantitative but noninvasive measure of penile corporal venous leakage. Seventy-four men were studied with duplex ultrasonography after intracavernosal injection of 60 mg of papaverine. Fourteen men had normal erection and served as controls. Sixty men had a 1-year history of transient fading or incomplete erections. In all subjects the peak systolic velocity and end-diastolic velocity were measured, and the resistance index was calculated (peak systolic velocity--end-diastolic velocity/peak systolic velocity). Men with normal erections had peak systolic velocities greater than 35 cm/sec and end-diastolic velocities less than 4.5 cm/sec (group 1). Patients with incomplete erections (group II) could be classified into three subgroups. Twenty-three patients with end-diastolic velocities greater than 4.5 cm/sec and normal peak systolic velocities greater than 35 cm/sec were suspected to have corporal venous leakage (group A). Eighteen patients had normal end-diastolic velocities less than 4.5 cm/sec. Twelve of this group had peak systolic velocities less than 35 cm/sec, and six had peak systolic velocities ranging from 37 to 44 cm/sec. These patients were suspected of having arterial insufficiency (group B). Fifteen patients with end-diastolic velocities greater than 4.5 cm and peak systolic velocities less than 35 cm were suspected of having both venous leakage and arterial insufficiency (group C). Twenty-one patients with abnormal diastolic flow underwent infusion pharmacocavernosometry to determine the saline maintenance infusion rate necessary to maintain an intracavernosal pressure of 90 to 100 mm Hg or a full erectile response.(ABSTRACT TRUNCATED AT 250 WORDS)     

Does the type of the Peyronie's curvature effect penile vascular parameters in normopotent men?

The aim of this study is to assess whether the type of penile curvature in normopotent men with Peyronie's disease affects the penile vascular doppler ultrasound parameters. Fifty-three normopotent patients within the stabilization phase of Peyronie's disease were evaluated retrospectively by means of color doppler ultrasonography. Bilateral cavernosal artery diameters before and after intracavernous papaverine injections, peak systolic and end diastolic velocities and the amount of leakage in the deep dorsal penile vein were compared in dorsal and ventral curvature groups of Peyronie's disease. 61% of the patients in dorsal and 59% in ventral Peyronie's curvature group have normal ultrasonographic penile vascular system. 35% and 3.3% in dorsal curvature group and 36.4% and 4.5% in ventral curvature group have venoocclusive dysfunction and mixed vascular pathologies, respectively, having no statistical correlation between them (p > 0.05). No arterial pathology was observed in any group. There was no correlation between the type of Peyronie's curvature and the penile doppler ultrasonographic findings in normopotent patients.     

Colour penile Doppler ultrasonography with intraurethral prostaglandin-E2: Preliminary results

Intraurethral instillation was used in place of intracavernosal injection of vasoactive agents for the colour Doppler investigation of patients with erectile dysfunction. A total of 19 patients were enrolled in this study. Colour penile Doppler ultrasonography was done with intracavernosal injection of papaverine-HCl 60 mg and intraurethral instillation of prostaglandin-E₂ 0.5mg. Arterial diameter, peak systolic velocity and end diastolic velocity were measured before and after papaverine injection and prostaglandin-E₂ instillation. Colour penile Doppler parameters increased statistically significantly after papaverine injection and prostaglandin-E₂ instillation (p<0.01). But we did not observe differences between the results after papaverine-HCl and prostaglandin-E₂. We believe that prostaglandin-E₂ may be used with colour Doppler ultrasonography in the evaluation of patients with erectile dysfunction.     

Study of cavernosal arterial anatomy using color and power Doppler sonography: impact on hemodynamic parameter measurement.

PURPOSE: We report on color and power Doppler ultrasound to study cavernosal arterial anatomy, and evaluate the impact of vascular anatomy on the measurement of hemodynamic parameters. MATERIALS AND METHODS: Cavernosal arterial anatomy of 42 patients with erectile dysfunction was evaluated using color and power Doppler ultrasound. A computerized waveform analysis was used to measure peak systolic velocity, end diastolic velocity and resistive indexes at various sites, including the penile crura, and proximal mid and distal penile shaft. Hemodynamic parameters were measured in each artery in cases of bifurcated or multiple cavernosal arteries. RESULTS: A total of 80 corpora were adequately evaluated. We observed a single artery without major proximal branches in 37 corpora, a single artery with major proximal branches in 17, bifurcated arteries in 15, 2 cavernosal arteries in 4 and marked arterial tortuosity in 1. In 6 corpora the main cavernosal artery arose from the superficial dorsal artery. The peak systolic velocity was highest at the proximal and decreased progressively at the distal site. The peak systolic velocity plus or minus standard deviation at the mid shaft averaged 69.3+/-30.0% of that at the proximal penile shaft. Of the 15 corpora with bifurcated arteries 67% had a 40% or greater difference in peak systolic velocity between the branches. Complete or partial occlusion of the cavernosal artery was identified in 3 corpora, and a dramatic difference in peak systolic velocity proximal and distal to the stenotic area was demonstrated. CONCLUSIONS: Cavernosal arterial anatomy is variable and hemodynamic parameters differ at various sites of measurement. Parameters should be measured at a consistent proximal site to obtain a reliable assessment. Variations in vascular anatomy and cavernosal artery pathology should be considered when interpreting color Doppler sonography and before penile vascular surgery.     

The role of colour duplex ultrasonography in the diagnosis of vasculogenic impotence.

Colour duplex ultrasonography was used to obtain peak systolic velocity (PSV) readings from cavernosal arteries at rest and during papaverine-induced tumescence. Results from 31 men with vasculogenic impotence were compared with those from 17 men with non-vasculogenic impotence and a control group of 6 potent men. In the flaccid state no significant differences in PSV readings were found between the vasculogenic and control groups. Following the injection of papaverine, men from the vasculogenic group without venous leakage were alone in having significantly lower PSV readings compared with the potent controls. All 23 men with normal penile haemodynamics had a mean PSV greater than or equal to 20 cm/s during tumescence. This was also the case for 19 (61%) of the vasculogenic group, including 9 (69%) of the 13 patients with venous leakage. The remaining 12 men in the vasculogenic group (39%) had a mean PSV less than 20 cm/s, this being diagnostic of an inadequate arterial inflow. Colour duplex ultrasonography can identify patients who have marked arterial insufficiency as the major cause of their impotence and hence allows more rational selection for angiography and revascularisation. Lesser degrees of arterial deficit are difficult to characterise using mean PSV readings alone.     

Different hemodynamic responses by color Doppler ultrasonography studies between sildenafil non-responders and responders

Aim： To determine if there are different penile hemodynamic patterns between sildenafil non-responders and responders by using color Doppler ultrasonography. Methods： A total of 69 erectile dysfunction （ED） patients aged 22-79 years were enrolled into the present study. Thirty-eight （55.1%） men with ED who did not respond to four attempts of treatment with 100 mg sildenafil after re-education were classified as sildenafil non-responders. A com- bination of three vasodilator drugs, 1.25 mg papaverine, 0.4 mg phentolamine and 5 ug prostaglandin E1, was given by intracavernous injection before penile Doppler ultrasonography was carried out. The erectile response to intracavernous injection and vascular parameters including peak systolic velocity （PSV）, resistance index （RI）, end diastolic velocity （EDV） and cavernosa artery diameter （CD） were measured and the results between sildenafil nonresponders and responders were compared. Results： No statistical difference in vascular parameters measured by Doppler ultrasonography studies between non-responders and responders was noted. Sildenafil non-responders had a poorer penile rigidity response to intracavernous injection than responders （P 〈 0.05）. Among patients with adequate PSV （〉 30 cm/s） and abnormal EDV （〉 5 cm/s）, individuals in the non-responder group had fewer positive responses to intracavernous vasodilator injection than in the responder group （35.3% vs. 72.2%, P 〈 0.05）. Advanced age and comorbidity with diabetes mellitus were significantly associated with sildenafil non-response （P 〈 0.05）. Conclusion： Sildenafil non-responders were characterized by a poorer penile rigidity response to intracavernous injection and had an associated impaired veno-occlusive mechanism. Advanced age and comorbidity with diabetes mellitus were two common factors associated with non-response.     

Alcock's canal releasing for pudendal artery syndrome resulting from gunshot injury

A 21-y-old man applied to hospital with a complaint of erectile dysfunction, which started soon after a gunshot injury. The entry of the bullet was at the middle right gluteal region without any exit hole. A pelvic X-ray revealed the bullet and the scattered particles. On penile Doppler ultrasonography, the peak systolic velocities (PCV) of the right and the left cavernosal arteries were 19 and 29 cm/s, respectively. Pudendal angiography revealed poor visualization of the right pudendal artery below the level of the bullet. The patient underwent a right-sided Alcock's canal releasing surgery. After the operation, on control penile Doppler ultrasonography, PCV on the right and the left cavernosal arteries were 53 and 35 cm/s, respectively. The control angiography revealed a normal right pudendal artery. The patient was fully potent 2 y after the operation. Not only the entrapment of pudendal nerve but also the pudendal artery may cause Pudendal canal syndrome. A gunshot injury may cause such a condition due to the reaction caused by the bullet. Pudendal canal decompression is a simple and effective treatment for pudendal canal syndrome.     

Usefulness of power Doppler ultrasonography in evaluating erectile dysfunction

OBJECTIVE: To evaluate deep penile arterial flow after an intracavernosal injection with papaverine in patients with erectile dysfunction (ED). PATIENTS AND METHODS: Twenty patients with ED were evaluated using power Doppler ultrasonography with a linear probe (8 MHz). Diagnostic tests were undertaken after an intracavernosal injection with 40 mg papaverine. The peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistive index (RI) were analysed. RESULTS: After injecting papaverine, seven patients had a normal erection and appropriate waveform patterns; their mean PSV was 30.7 cm/s, the EDV 4.42 cm/s and the RI 0.85. There was tumescence and elongation of the penis with no rigidity in eight patients; their mean PSV was 23.9 cm/s, the EDV 7.34 cm/s and the RI 0.72. There was no erection in five patients. The abnormal flow values showed insufficient arterial vessels in a quarter of the men, venous leakage in 15% and mixed ED in 20%. CONCLUSION: The power Doppler technique allows the accurate location and evaluation of deep penile arteries. Vascular pathology may be differentiated after an intracavernosal injection with a vasomotor agent. Recognising the pathological pattern assists in choosing the best method of treatment.     

Quantitative evaluation of the penile vascular status by means of the 99mTc-penogram in conjunction with either papaverine or prostaglandin E1 in the anaesthetised baboon model.

The evaluation of both the arterial blood supply and the venous drainage of the penis is essential in the assessment of the impotent male. The vasoactive drugs papaverine and prostaglandin E1, as intracavernous injections, cause penile erections by influencing arterial blood supply and venous drainage. These drugs were used in a baboon model together with a 99mTc-penogram to provide information on the vascular status of the penis. An increase in penile blood pool was observed, more dramatic and rapid after administration of papaverine. A quantitative assessment of the vascular status seems possible and will next be monitored in a vascular-compromised baboon for purposes of clinical application.     

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.     

Effectiveness of vardenafil versus papaverine in penile Doppler ultrasonography

PURPOSE: To evaluate erectile dysfunction, penile color Doppler ultrasound is currently considered the best method. But intracavernous injection is invasive and has adverse effects, such as prolonged erection and risk of priapism. In our study we want to evaluate whether vardenafil can be used instead of papaverine in penile Doppler ultrasonography. MATERIALS AND METHODS: A total of 24 patients with erectile dysfunction underwent color Doppler ultrasound before and after intracavernous injection of 60 mg papaverine with genital and audiovisual sexual stimulation. Peak flow and end diastolic velocity were measured in the recorded waveforms obtained 0, 1, 5, 10 and 20 min after injection. The patients also underwent color Doppler ultrasound after a 10-mg oral dose of vardenafil with genital and audiovisual sexual stimulation and at least 5 days after the prior examination. The same parameters were measured at 30, 45, 60, 75 and 90 min after the drug administration. We compared the results with the values obtained after papaverine injection. RESULTS: After oral vardenafil mean peak flow velocity significantly increased starting at 30 min and achieving a maximum value at 60 min. There were no significant differences in the 2 methods in mean peak velocity 1, 5, 10 and 20 min after papaverine injection, and 30, 45, 60, 75 and 90 min after oral vardenafil administration. Although papaverine injection is the gold standard for penile color Doppler ultrasound, it has severe adverse effects such as prolonged erection which we observed in 3 patients (12.5%) and required pharmacological detumescence. After vardenafil no severe adverse effects were observed. CONCLUSIONS: Vardenafil administration achieved increased peak flow velocity comparable to that after intracavernous papaverine injection. With no prolonged erection vardenafil is a safer alternative compared to more invasive intracavernous injection and is also an alternative for patients who fear injections.     

Correlation between penile angiography and duplex scanning of cavernous arteries in impotent men

During the diagnostic evaluation of patients with vasculogenic impotence duplex scanning has been proposed as a reliable noninvasive method to evaluate the cavernous arteries. However, the sensitivity and specificity of this test have never been elucidated. To provide insight into the clinical value of this test 25 men who presented with impotence and failed to respond to 60 mg. intracavernous papaverine were evaluated with duplex scanning and the results of this modality were compared to penile angiography. The cavernous arteries were considered normal by duplex scanning if the artery demonstrated either a 60% or greater increase in diameter and/or a peak flow velocity of greater than 25 cm. per second 5 minutes after papaverine injection. Penile angiography was considered normal if both cavernous arteries were visualized and appeared to be normal radiographically (after intracorporeal papaverine). In the 25 patients studied there was no significant difference in peak flow velocity between patients with normal or abnormal cavernous arteries by angiography. In addition, arterial dilatation (more than 60%) after papaverine injection did not correlate with the results of the angiogram. These data demonstrate that duplex scanning of the cavernous arteries does not correlate well with what is observed by penile angiography in a selected population of men with vasculogenic erectile dysfunction. Since penile angiography itself has limitations in the evaluation of the penile arteries, the reliability of duplex scanning to identify cavernous artery dysfunction needs additional confirmation.     

Evaluation of vasculogenic erectile impotence using penile duplex ultrasonography

A total of 140 patients underwent penile vascular evaluation with intracavernous papaverine injection combined with duplex ultrasonography. Of these patients 8 were potent men who were evaluated for reasons other than erectile failure. These potent men were used as controls to obtain normal values. The remaining 132 patients had erectile impotence of various etiologies. Real-time imaging with high resolution, high frequency probes allowed for visualization of the cavernous arteries along the entire length in addition to accurate measurement of the diameter. Simultaneous selectively focused Doppler ultrasonography was used to measure the blood velocity and other vascular parameters in the cavernous and dorsal arteries. Comparison of measurements before and after papaverine injection allowed for objective interpretation of the injection results. The results were analyzed and compared to other data available on the same patients, such as history and physical examination, nocturnal penile tumescence, penile blood pressures, selective arteriography and dynamic cavernosography. In addition to the 8 potent men, there were 35 patients (27% of the impotent patients) whose vascular findings were normal. A total of 78 patients (59% of the impotent patients) had arterial insufficiency; a subgroup of 13 patients had the pelvic arterial steal syndrome. Dynamic cavernosography confirmed venous leak in all 19 patients (14% of the impotent patients) whose penile duplex ultrasonography suggested the possibility of a venous leak. Ten patients (7%) had prolonged erection after papaverine injection and they were managed without consequences. One patient had a small hematoma that resolved uneventfully. Penile duplex ultrasonography was a helpful and objective method to evaluate vasculogenic impotence.     

Duplex scanning in suspected vasculogenic impotence: a worthwhile exercise?

The value of duplex scanning in the assessment of impotence was evaluated in 146 impotent men. Scanning was by means of a Diasonics DRF 400 and penile artery measurements were taken before and after the intracorporeal injection of papaverine hydrochloride. The penile/brachial index was measured in 82 patients and its predictive value compared with the results of duplex scanning and papaverine-induced erection. On scanning evidence of good arterial inflow but poor erections, indirect evidence of venous leakage was assumed. The results showed that the deep artery responses best characterised the erectile response, with the dorsal artery being less helpful. All 37 patients with full erections following papaverine exhibited bilateral deep artery peak velocities of greater than or equal to 25 cm/s. Of the remaining 109 sub-optimal responders, 17 also has this finding; all had undergone dynamic cavernosography, with 16 exhibiting venous leakage. The penile/brachial index was found to classify 13 patients incorrectly. A critical value of deep artery response to attain erection is postulated, enabling more logical use of cavernosography. The penile/brachial index was shown to be suspect and it was concluded that duplex scanning is a useful, non-invasive method in the assessment of impotence.     

Functional evaluation of penile arteries with duplex ultrasound in vasodilator-induced erection

In 657 impotent patients in whom erection was induced by intracavernous injection of papaverine, we evaluated changes in the pulsation, diameter, and blood flow velocity of the penile arteries by duplex sonography and pulsed Doppler spectrum analysis. An additional 18 patients who were proved to have good erection by nocturnal tumescence testing were used as controls. All patients were studied before achieving full erection after papaverine injection. In the flaccid state, the inner diameter of the deep penile arteries averaged 0.51 mm, and blood flow velocity was rarely measurable. The normal arterial reaction to papaverine was an initial increase in the inner diameter of the scanned segment of the cavernous artery with good concentric pulsations and a mean peak blood flow velocity of 34.8 cm per second and a mean diameter of 0.89 mm. With this technique, we assessed the functional capability of each deep and dorsal artery. Arterial and erectile response allowed indirect evaluation of the venous system. Of the 657 patients, 48 had neurogenic or psychogenic impotence or both. In 97, impotence could be ascribed to venogenic causes, in 210 to arteriogenic causes, and to mixed arteriogenic and venogenic causes in 282 patients. The exact cause of impotence in the remaining 20 patients could not be determined. Statistically, patients who were older or had diabetes mellitus or coronary artery disease tended to have smaller penile arteries and lower peak blood flow velocity after papaverine injection.     

选择不同剂量他达拉非治疗ED的临床标准初步探索

目的:本文通过观察不同剂量他达拉非(希爱力)对于勃起功能障碍(ED)患者的治疗效果,探索他达拉非剂量与阴茎血流彩色多普勒参数之间的关系。方法:对136例ED患者在治疗前后进行IIEF-5评分同时用彩色多普勒超声联合阴茎血管活性药物前列腺素(PGE1)注射试验,检测阴茎双侧海绵体动脉的收缩期最大流速(PSV)。根据治疗前不同的PSV值,随机分为4组,采用了疗程为4周的隔日晚餐后口服不同剂量他达那非的用药方案。A组:PSV>15 cm/s,选择10 mg剂量;B组:PSV>15 cm/s,选择5 mg剂量;C组:PSV<15 cm/s,选择10 mg剂量;D组:PSV<15 cm/s,选择5 mg剂量。结果:治疗4周后,经统计学分析,4组IIEF-5评分以及阴茎双侧海绵体动脉的PSV与治疗前相比均有显著提高(P<0.01)。而且治疗4周后,A组与B组IIEF-5评分以及阴茎双侧海绵体动脉的PSV之间没有明显差异;C组却显著高于D组(P<0.01)。结论:隔日口服不同剂量的他达那非均能有效提高ED患者阴茎海绵体动脉的收缩期最大流速,改善患者的勃起质量。PSV>15 cm/s的ED患者可选择小剂量5 mg隔日;PSV<15 cm/s的ED患者尽量选择较大剂量10 mg隔日,以取得更好的疗效。     

Impact of aging on penile hemodynamics in men responding normally to prostaglandin injection: A power Doppler study

AIM: Hemodynamic changes with aging in the penile arterial circulation, including the helicine arteries, were evaluated with power Doppler imaging in erectile dysfunction patients with a normal response to prostaglandin injection. METHODS: In 36 patients with erectile dysfunction and no definite vascular risk factors, 72 corpora were examined using power Doppler imaging. Patients were classified by age: younger than 40 years, from 40 to 49, or 50 and older. Hemodynamic variables in the cavernous arteries, helicine arteries and dorsal arteries were measured after intracavernous injection of prostaglandin E1 (20 microg). RESULTS: All cavernous arteries had a maximum peak systolic velocity of greater than 35 cm/s and a minimum end-diastolic velocity of less than 0 cm/s. Mean peak systolic velocity in the cavernous artery differed between groups (P = 0.016), especially between the younger than 40 age group and the 40-49 age group. Peak systolic velocity correlated negatively with age (P = 0.0048). In the helicine arteries and dorsal arteries, peak systolic velocity did not differ between groups and showed no correlation with age. End-diastolic velocity, resistance index and acceleration time did not differ between groups, or correlate with age for any artery. CONCLUSIONS: Hemodynamic change with aging occurs predominantly in the cavernous arteries, where peak systolic velocity decreases. The arterial circulation beyond the cavernous arteries, including the helicine arteries, as well as veno-occlusive mechanisms, may have an important role in maintaining erectile function in aging.