Sildenafil citrate is a highly effective erectogenic agent. However, predicting which patients will respond to this agent is often difficult. While the patient response to this agent is dependent on the nitric oxide-guanylate cyclase-cyclic guanosine monophosphate cascade, the integrity of penile arterial flow and venocclusive mechanism is also important. Duplex Doppler penile ultrasonography can reliably document penile hemodynamics. This study aimed at defining response rates based on degree of penile vascular sufficiency.
This study enrolled patients who met strict criteria for sildenafil citrate response who had also undergone penile ultrasound. Correlation was drawn between the nature and the severity of the vascular insufficiency and the response rate to sildenafil citrate.
The distribution of vascular diagnoses was arteriogenic 64%, venogenic 6%, mixed vascular insufficiency 18%, and normal 12%. The best response was seen in those men with normal vascular studies, 80% responding. Fifty-three percent of all men with any abnormality on penile ultrasound responded; 65% of men with arteriogenic erectile dysfunction (ED), 25% of patients with venogenic ED, and 6% of men with a mixed vascular insufficiency were responders. There was a correlation between the degree of vascular impairment and the response rate. All men with venogenic ED who responded had mild leak.
These data demonstrate a correlation between the nature and severity of penile vascular disease and the ability to respond to sildenafil citrate. These data may be useful to the sexual medicine practitioner when counseling patients regarding oral erectogenic therapy.
"The common underlying vascular abnormalities were corporal VOD alone or combined with arterial insufficiency. These abnormalities were the causes of failure, and are very difficult to treat, as those cases were predicted to be non-responders according to Mullhall et al. ; they stated that the presence of any degree of venous leak resulted in reduced efficacy of sildenafil, with only five of 46 (11%) patients responding to sildenafil. Also, corporeal VOD alone or combined with arterial disease is the specific haemodynamic abnormality causing no response to intracavernous pharmacotherapy . "
[Show abstract][Hide abstract] ABSTRACT: Objective
To investigate the effect of chronic use of sildenafil and intracavernous injection (ICI) with trimix in men not responding to on-demand monotherapy with sildenafil or ICI with prostaglandin-E1 (PGE1).
Patients and methods
The study included 40 patients with erectile dysfunction (ED), with a mean (SD) age of 50.7 (11.3) years and unresponsive to on-demand sildenafil or ICI with PGE1 as monotherapy. They were assessed using the Sexual Health in Men (SHIM)-5 score for ED severity, penile colour Doppler ultrasonography (CDUS) for peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistance index (RI) with an ICI test using 0.25 mL of trimix of papaverine, PGE1 and phentolamine. Testosterone, prolactin and cholesterol levels were assessed. Patients received 25 mg sildenafil daily for 8 weeks, combined with twice weekly ICI with 0.25 mL of trimix. After treatment, the Erection Hardness Score (EHS), penile CDUS with ICI and ED Inventory of Treatment Satisfaction were assessed.
The mean (SD) SHIM-5 score before treatment was 8.3 (0.5) in 15 of the 40 men and 6.3 (0.4) in 25. Penile haemodynamics were normal in five (13%), showed arterial insufficiency in five (13%), venous occlusive disease in 26 (65%) and mixed vascular in four (10%). There was an improved SHIM-5 score in 28 (70%) patients, as shown by their haemodynamic values, duration of erection and EHS with therapy, and 66% satisfaction with treatment. Adverse effects (penile pain, headache, facial flushing, dyspepsia, nasal congestion, dizziness) were reported in 17 patients (43%).
Chronic use of trimix plus daily low-dose sildenafil improved penile haemodynamics in these patients with ED not responding to on-demand phosphodiesterase-5 inhibitors or ICI with PGE1 monotherapy.
Arab Journal of Urology 06/2011; Volume 9, 153–158(2):153-158. DOI:10.1016/j.aju.2011.06.008
"In the next future, non-invasive vascular testing should be recommended in all impotent men presenting with vascular risk factors, especially in those not responding to first-line orally active drugs and seeking for an explanation as to why these agents failed in their cases. In such cases, a frequent diagnosis of venous leakage or mixed arterio-venogenic ED has recently been reported (Mulhall et al., 2005), thus highlighting the role of penile duplex ultrasound in the prediction of response to oral agents. The advantage of ultrasound is the minimally-invasive nature of the procedure and the ability to screen patients to identify a normal erectile response. "
[Show abstract][Hide abstract] ABSTRACT: A number of disease processes of the penis including Peyronie's disease, priapism, penile fractures and tumors are clearly visualized with ultrasound. Diagnostic evaluation of erectile dysfunction (ED) by penile dynamic colour-duplex Doppler ultrasonography (D-CDDU) is actually considered a second level approach to ED patients because of the fact that intracavernous injections test IV with prostaglandin-E(1) may provide important information about the patients' erectile capacity. However, no direct vascular imaging and a high percentage of false negative diagnoses of vasculogenic ED are its major pitfalls and subsequent treatment decisions remain quite limited. The occurrence of ED and its sentinel relationship to cardiovascular disease has prompted more accurate vascular screening in all patients even in the absence of cardiovascular risk factors. The sonographic evaluation of the intima-media thickness of the carotid arteries may sometimes represent an early manifestation of diffuse atherosclerotic disease and endothelial damage. This latter finding is often the cause of failure to oral agents, i.e. phosphodiesterase inhibitors, because of inability of the dysfunctional endothelium to release nitric oxide. D-CDDU represents an accurate tool to investigate cavernous artery inflow and venous leakage when compared with more invasive diagnostic techniques i.e. selective arteriography and dynamic infusion cavernosometry along with cavernosography.
International Journal of Andrology 01/2006; 28 Suppl 2(s2):61-3. DOI:10.1111/j.1365-2605.2005.00587.x · 3.70 Impact Factor
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