Colour duplex sonography in the assessment of impotence

Doppler evaluation of erectile dysfunction – Part 1

Erectile dysfunction (ED) is the consistent inability to achieve and maintain an erection sufficient for satisfactory sexual activity. Erectile dysfunction affects as many as 30 million men in America, with an increasing prevalence with age. Erectile dysfunction is secondary to organic, psychogenic and combined causes. The first part of this review article describes the guidelines for evaluation and treatment plans for men with ED. It also describes the normal sonographic anatomy of the penis, sonographic technique for evaluation of ED and the normal phases of erection.

Sildenafil citrate vs intracavernous alprostadil for patients with arteriogenic erectile dysfunction: a randomised placebo controlled study

We compared the effectiveness of sildenafil citrate and alprostadil in improving arterial penile inflow (peak systolic velocity (PSV)) and penile rigidity in 55 patients with erectile dysfunction caused by atherosclerosis. A total of 35 patients with pure vasculogenic impotency were randomly assigned to alprostadil (Av group; n=11), sildenafil (Sv group; n=12), or placebo (P group; n=12), and 20 patients with nonvasculogenic impotency were randomly assigned to alprostadil (A group; n=10) or Sildenafil (S group; n=10): Av and A used alprostadil injection (capable of giving a full erection) once a week for 1 month, Sv and S took daily oral sildenafil (25 mg) for 1 month, and P took daily oral placebo for one month. The PSV was measured with Duplex sonography and penile rigidity was assessed using the IIEF-15 questionnaire, both of which were administered before and after treatment. Although both treatments improved penile rigidity, they increased PSV only in the Av and Sv groups. Our results suggest that alprostadil and oral therapy should be the starting therapy in men with vasculogenic impotency, whereas alprostadil should be avoided as the first-line approach in men with nonvasculogenic impotency.

Is sildenafil failure in men after radical retropubic prostatectomy (RRP) due to arterial disease? Penile duplex Doppler findings in 174 men after RRP

Sildenafil is frequently the first-line treatment for post-radical retropubic prostatectomy (RRP) erectile dysfunction (ED) with maximum treatment satisfaction rates of 43%-80%. The etiology of erectile dysfunction after RRP has been attributed to psychogenic, vascular, veno- occlusive or nerve injury causes. The purpose of this study was to gain insight into the penile duplex Doppler arterial parameters in men with ED after RRP who failed sildenafil. The purpose was to assess whether sildenafil failure after RRP is associated with underlying corporal arterial disease. A total of 174 consecutive men presenting with sildenafil refractory ED after nerve-sparing RRP underwent color duplex penile Doppler evaluation with vasoactive injection. Mean age was 59.6 y and mean time from surgery was 11.6 months. Some 81% (141/174) of the men had no pre-operative ED (PED). Significant differences in penile duplex Doppler parameters for arterial disease were seen between men with and without PED. In men without PED, 19% (27/141) manifested arterial insufficiency. However, in men with PED, 50% (16/33) demonstrated arterial disease. Nerve sparing status did not affect the presence of arterial disease. Sildenafil refractory erectile dysfunction after RRP in men without PED is not predominantly associated with penile Doppler parameters consistent with arterial insufficiency.

Duplex ultrasound evaluation of cavernosal peak systolic velocity and waveform acceleration in the penile flaccid state: clinical significance in the assessment of the arterial supply in patients with erectile dysfunction

The aim of this paper was to establish if duplex ultrasound parameters obtained for assessment of the patency of cavernosal arteries in the penile flaccid state can give sufficient clinical information without the use of intracavernosal injection of vasodilatory drugs. We assessed mean cavernosal peak systolic velocity (PSV) in the penile flaccid state (basal PSV), and after PGE1 injection (dynamic PSV) in 339 unselected patients with erectile dysfunction. In 55 of these patients the waveform acceleration in the flaccid state was also assessed. The results of the study can be summarized as follows: (1) a significant relationship was found between basal and dynamic PSV in the 339 patients (r=0.477; p < 0.0001); (2) a basal PSV >12.5 cm/sec was predictive of a dynamic PSV >/=30 cm/sec in 129/139 (92.8%) of the patients, whereas in patients with a basal PSV </=12.5 a dynamic PSV both > or <30 cm/sec could be found; and (3) an acceleration >1 m/sec2 in the flaccid state was coupled to a dynamic PSV >30 cm/sec in 43/46 (93.5%) of the patients independent of the basal PSV. In conclusion, these results suggest that the combined duplex ultrasound assessment of PSV and waveform acceleration in the penile flaccid state can predict arterial dynamic inflow in the majority (51/55; 92.7%) of patients with erectile dysfunction, with less time and expense and less discomfort for the patient.

The correlation among cavernous pressure, penile rigidity and resistance index

PURPOSE

We define the precise meaning and diagnostic significance of the resistance index generated by duplex scanning.

MATERIALS AND METHODS

In 80 patients penile rigidity was clinically evaluated and a penile duplex scan was performed after intracavernous injection of 10 microg. prostaglandin E1. The intracavernous equilibrium pressure was measured in 34 of these patients.

RESULTS

We found a statistically highly significant linear relationship among cavernous pressure, resistance index and penile rigidity (p <0.001).

CONCLUSIONS

The resistance index and clinical degree of penile rigidity are 2 expressions of intracavernous pressure. Clinical observation of erection is equivalent to the resistance index in screening for cavernous leakage.

Power-Doppler with echo amplification in studying the microcirculation in arteriogenic erectile dysfunction: Preliminary experience

The authors emphasise the usefulness of Power-Doppler with echo amplification in studying the arterial microcirculation in selected patients with erectile deficit.

Ultrasound evaluation of the penis for assessment of impotence

Image directed Doppler ultrasonography of the cavernous arteries provides functional, quantifiable assessment of penile arterial flow during a pharmacological erection. In this respect, this modality is superior to arteriography as a means of evaluating arteriogenic impotence. Peak flow velocity, arterial dilatation, and vessel pulsation are the most reliable ultrasonic indicators of arterial health. Aberrant arterial anatomy should be noted as this may contribute significantly to total penile blood flow. A thorough understanding of erectile physiology and anatomy is necessary to properly perform and interpret Doppler ultrasound results.

Evaluation of impotent men with intracorporeal injection of papaverine and colour Doppler ultrasound

Fifty impotent patients have been evaluated with intracorporeal injection of papaverine and colour Doppler ultrasound. The papaverine tests were negative in 34 of 50 patients. Nineteen of 34 patients with negative papaverine results showed normal colour Doppler findings. In 14 of 16 patients with positive papaverine results the colour Doppler analysis revealed normal structure and functions. Correlation between intracorporeal papaverine injection and colour Doppler ultrasound results was found in 59% (p < 0.01). We concluded that intracorporeal papaverine injection is an effective, simple diagnostic test for beginning evaluation of impotent men. However, this screening test should be supported by colour Doppler ultrasound.

Assessment and treatment of impotence

Impotence is a common problem. History is primarily relied on to diagnose psychogenic impotence. Sex therapy is an effective treatment. Antihypertensive and psychiatric medicines often cause impotence, but most medicines should be considered a cause if this is supported by the history. Hormonal causes should be suspected in a patient with decreased libido or decreased testicular size, and testosterone should be measured in these cases. Hormone replacement may restore sexual function in hypogonadal men. Doppler sonogram or arteriography should be used to diagnose vascular impotence for men who would be good surgical candidates. Only young men without other illness are considered. There is little need to test neurologic function because there is no specific treatment for neurogenic impotence. These patients and patients who do not respond to the aforementioned treatments should be offered the vacuum erection device, penile self-injection therapy, or penile prosthesis. Choice depends on comorbid illness as well as patient preference. A basic algorithm for the evaluation and treatment of impotence is given in Figure 2.

Adenosine modulation of neurotransmission in penile erection

1. Adenosine inhibited the noradrenaline-induced contraction of rabbit corpus cavernosum in a dose-dependent manner. The effect of adenosine was greater in intact corpus cavernosa than in endothelium-denuded preparations. This finding indicates that the relaxing effect of adenosine is partially endothelium-dependent and involved in the release of endothelium-derived relaxing factors. 2. Adenosine and its analogues relaxed the noradrenaline-induced contractile response as well as inhibited the transmural nerve induced contraction with the potency order: NECA > R-PIA > adenosine. These data indicate that adenosine can modulate both the non-adrenergic non-cholinergic and adrenergic neurotransmission. DMPX, an adenosine antagonist selective for the A2 receptors, abolished the electrically elicited relaxation. However, CGS 21680, selective for A2a receptor, had no effect on relaxation. Therefore, adenosine receptors involved in the modulation of neurotransmission in rabbit corpus cavernosum appear to be A2b subtype. 3. Adenosine also induced an increase in human cavernosal arterial velocity and resistive index measured by colour duplex sonography. The combination of adenosine and 10 micrograms prostaglandin E1 was more effective in resistive index and erection grade than 20 micrograms prostaglandin E1 alone. Our results suggest that adenosine seems to be an important neuromodulator for penile erection and can be an effective and alternative combination in the treatment of impotence.

Morphodynamic assessment of penile circulation in impotent patients: the role of duplex and color Doppler sonography

Duplex and color Doppler sonography were used to assess the vascular status of 240 impotent patients. The tests were performed before and after intracorporal injection of a standard dose of a vasoactive mixture and measurements were done both at the crura and at the midshaft of the penis. Particular care was taken in the evaluation of cavernosal arteries diameter, wall pulsatility, morphology of spectral waveform, blood flow acceleration, systolic and diastolic flow velocity and flow volume. Resistance and pulsatility indexes of the cavernosal arteries were also measured. Flow along the deep dorsal vein was quantified when possible. Cavernosal artery peak systolic flow velocity, flow volume and acceleration were the best indicators of arterial penile circulation. Persistently elevated (> 10 cm/s) diastolic flow in the cavernosal arteries positively correlated with a diagnosis of venogenic impotence obtained by dynamic infusion cavernosometry--cavernosography in almost 80% of cases. Duplex and color Doppler sonography permit to thoroughly evaluate cavernosal arteries function and seem to have a promising role in the study of the veno-occlusive mechanism of the corpora cavernosa.