Vascular Erectile Dysfunction Research Articles

The Role of Penile Color-Duplex Ultrasound for the Evaluation of Erectile Dysfunction

In the era of orally active agents, dynamic penile color-duplex ultrasound (D-PCDU) is not considered a necessary first screening for all patients with erectile dysfunction (ED). Various parameters, such as peak systolic flow velocity, end diastolic velocity, resistance index, acceleration time, and degree of arterial dilatation, have been suggested for the diagnosis of vascular ED by D-PCDU. To highlight the clinical utility and evidence-based interpretation of D-PCDU criteria. Extensive, unsystematic PubMed literature search reviewing relevant data on D-PCDU in the evaluation of male ED. The advantage of ultrasound is the minimally invasive nature of the procedure and the ability to screen patients to identify a normal arterial response of cavernous arteries. Men with sexual dysfunctions above 55 years of age and comorbidities are more likely to have multi-organ vascular dysfunction and may necessitate further testing because erectile failure may be the first presenting symptom requiring investigation and treatment even in the absence of cardiovascular risk factors. All patients affected with Peyronie's disease and younger men with persistent ED, a history of pelvic traumas, or fractures of the penile shaft should be offered ultrasonographic penile blood flow studies before referral to surgery or more invasive vascular investigations. In the near future, D-PCDU may be used in preference to patients presenting with or without vascular risk factors, particularly those not responding to first-line orally active drugs and seeking an explanation as to why these agents failed.

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.

ORIGINAL RESEARCH—ERECTILE DYSFUNCTION: Erectile Dysfunction Severity Might be Associated with Poor Cardiovascular Prognosis in Diabetic Men

ABSTRACT Introduction Although erectile dysfunction (ED) might be associated with coronary heart disease (CHD), there is no evidence it predicts poor cardiovascular prognosis. On the other hand, an abnormal heart rate profile during exercise stress testing predicts poor cardiovascular prognosis in high-risk patients, such as diabetic men, even in the absence of CHD. Aim In order to study if ED predicts poor cardiovascular prognosis in high-risk patients, we examined the association between ED and heart rate profile during exercise stress testing in diabetic men with no CHD. Main Outcome Measures Erectile dysfunction severity, exercise capacity during exercise stress testing, and heart rate decrease after exercise stress testing. Methods A retrospective study. The medical charts of diabetic men with vascular ED from a single-sex clinic were reviewed, as well as the medical charts of body mass index (BMI)- and age-matched diabetic men without ED going through routine check-ups. All men underwent routine treadmill stress testing according to the Bruce protocol in order to characterize heart rate profile during exercise. The Sexual Health Inventory for Men (SHIM) questionnaire was used to characterize ED. Results Included were 18 diabetic men with ED (SHIM questionnaire scores 5–21) and 18 diabetic men without ED (SHIM questionnaire scores 22–25), 40 years of age or older. None of the men had signs of coronary insufficiency during exercise treadmill stress testing. Although the two groups did not statistically differ with respect to the mean age, the mean BMI, the prevalence of cardiovascular risk factors, and the mean exercise treadmill stress testing findings, the SHIM questionnaire scores were significantly associated with low metabolic equivalents (r = 0.51, P = 0.03) and delayed heart rate recovery during the first 2 minutes after exercise (r = 0.55, P = 0.018) only among diabetic men with ED. Conclusion Erectile dysfunction severity might be associated with poor cardiovascular prognosis in adult diabetic men with no CHD.

Presence of LDL Modified by Myeloperoxidase in the Penis in Patients with Vascular Erectile Dysfunction: A Preliminary Study

ObjectiveErectile dysfunction (ED) is a major vascular disorder. Atherosclerosis is closely related to lipoprotein metabolism and especially, oxidative modifications of low-density lipoproteins (LDLs), which are involved in early development of the atherosclerotic lesions. Current major questions include how LDLs are oxidised (OxLDL) in vivo. Myeloperoxidase (MPO) is an enzyme present in the azurophile granules of neutrophils and monocytes that can contribute to LDL oxidation in the presence of H2O2. We have developed a new monoclonal antibody against LDL modified by MPO (Mox-LDL) and have used it on penile biopsies from patients operated on for penile implant. MethodsSeven patients with vascular ED and one impotent patient after radical prostatectomy (RP) underwent biopsy of the cavernous body during penile implant procedures. An immunohistochemical study with a monoclonal antibody against Mox-LDL and an antibody against apoprotein B (ApoB), the protein moiety of LDL, to confirm the presence of LDL was performed. ResultsThe staining was positive for Mox-LDL and ApoB and was present between the endothelial cells of the sinusoid spaces and the smooth muscle cells in the seven patients with vascular ED. The patient with RP was negative for Mox-LDL. DiscussionBecause it is known that modified LDL could decrease nitric oxide production, Mox-LDL could be one of the agents responsible for ED. Further studies are needed to confirm this hypothesis.

Subclinical Coronary Artery Atherosclerosis in Patients With Erectile Dysfunction

OBJECTIVES The purpose of our study was to assess the prevalence and extent of coronary artery atherosclerosis in asymptomatic patients with vascular erectile dysfunction (ED). BACKGROUND An association between ED and ischemic heart disease has been suggested, but it is unknown if it represents a marker of subclinical coronary atherosclerosis. METHODS We studied 70 consecutive patients with vascular ED, evaluated by penile Doppler, and 73 control subjects with no history of coronary artery disease. We measured traditional coronary risk factors, circulating levels of C-reactive protein (CRP), endothelial function by ultrasound of brachial artery, and coronary artery calcification by multi-slice computed tomography. RESULTS The patients and the control group were similar for age, race, and coronary risk score. Patients with ED had significantly higher high-sensitivity C-reactive protein levels (2.62 vs. 1.03 mg/l, p < 0.001). Flow-mediated dilation of the brachial artery was more impaired in patients with ED than in controls (2.36 vs. 3.92, p < 0.001). Coronary artery calcification was more frequent in individuals with ED than in control subjects (p = 0.01). Multiple logistic regression analysis showed that patients with ED had an overall odds ratio of 3.68 for having calcium score above the 75th percentile, compared to the controls. CONCLUSIONS Coronary atherosclerosis is more severe in patients with vascular ED; ED predicts the presence and extent of subclinical atherosclerosis independent of traditional risk factors for cardiovascular disease. Thus, ED may be considered an additional, early warning sign of coronary atherosclerosis.

Curing erectile dysfunction: Pro

This study tested the hypothesis that sildenafil daily for 1 year can cure vascular erectile dysfunction (ED). In a prospective, randomized controlled trial, patients were assigned to two groups: group I, 50 mg of sildenafil daily at bedtime; group II, 50 to 100 mg of sildenafil on demand. The primary efficacy measures were International Index of Erectile Function domain score and peak systolic velocity (PSV) of penile arteries after treatment and following the nonmedicated periods. Treatment with 50 mg daily sildenafil for 1 year resulted in enduring normalization of erectile function in 59% of patients and a PSV of the cavernous arteries improved from 29.4 ± 9.8 cm/sec to 38.9 ± 10.3 cm/sec (P < 0.05). Sildenafil taken daily for 1 year resulted in ED regression and may be a useful tool for curing ED.

Subclinical Coronary Artery Atherosclerosis in Patients With Erectile Dysfunction

The purpose of our study was to assess the prevalence and extent of coronary artery atherosclerosis in asymptomatic patients with vascular erectile dysfunction (ED). An association between ED and ischemic heart disease has been suggested, but it is unknown if it represents a marker of subclinical coronary atherosclerosis. We studied 70 consecutive patients with vascular ED, evaluated by penile Doppler, and 73 control subjects with no history of coronary artery disease. We measured traditional coronary risk factors, circulating levels of C-reactive protein (CRP), endothelial function by ultrasound of brachial artery, and coronary artery calcification by multi-slice computed tomography. The patients and the control group were similar for age, race, and coronary risk score. Patients with ED had significantly higher high-sensitivity C-reactive protein levels (2.62 vs. 1.03 mg/l, p < 0.001). Flow-mediated dilation of the brachial artery was more impaired in patients with ED than in controls (2.36 vs. 3.92, p < 0.001). Coronary artery calcification was more frequent in individuals with ED than in control subjects (p = 0.01). Multiple logistic regression analysis showed that patients with ED had an overall odds ratio of 3.68 for having calcium score above the 75th percentile, compared to the controls. Coronary atherosclerosis is more severe in patients with vascular ED; ED predicts the presence and extent of subclinical atherosclerosis independent of traditional risk factors for cardiovascular disease. Thus, ED may be considered an additional, early warning sign of coronary atherosclerosis.

Pathophysiology of Erectile Dysfunction

Multiple regulatory systems are involved in normal erectile function. Disruption of psychological, neurological, hormonal, vascular, and cavernosal factors, individually, or in combination, can induced erectile dysfunction (ED). The contribution of neurogenic, vascular, and cavernosal factors was thoroughly reviewed by our committee, while psychological and hormonal factors contributing to ED were evaluated by other committees. To provide state of the art knowledge on the physiology of ED. An international consultation in collaboration with the major urology and sexual medicine associations assembled over 200 multidisciplinary experts from 60 countries into 17 committees. Committee members established specific objectives and scopes for various male and female sexual medicine topics. The recommendations concerning state-of-the-art knowledge in the respective sexual medicine topic represent the opinion of experts from five different continents developed in a process over a 2-year period. Concerning the pathophysiology of ED committee, there were seven experts from five different countries. Expert opinion was based on the grading of evidence-based medical literature, widespread internal committee discussion, public presentation, and debate. The epidemiology and classification of neurogenic ED was reviewed. The evidence for the association between vascular ED and atherosclerosis/hypercholesterolemia, hypertension and diabetes was evaluated. In addition, the pathophysiological mechanisms implicated in vascular ED were defined, including: arterial remodeling, increased vasoconstriction, impaired neurogenic vasodilatation, and impaired endothelium-dependent vasodilatation. The possible mechanisms underlying the association between chronic renal failure and ED were also evaluated as well as the evidence supporting the association of ED with various classes of medications. A better understanding of how diseases interfere with the physiological mechanisms that regulate penile erection has been achieved over the last few years, which helps establish a strategy for the prevention and treatment of ED.

Might erectile dysfunction be due to the thermolabile variant of methylenetetrahydrofolate reductase?

Hyperhomocysteinemia is considered one of the most important cardiovascular risk factors increasing considerably the risk of stroke and myocardial infarction. With respect to endothelial function, direct effects of hyperhomocysteinemia on vascular endothelial cells have been demonstrated through the reduction of endothelial nitric oxide production. In this paper, we report the case of a young man with homozygote genotype mutated with 5-methylenetetrahydrofolate reductase (MTHFR) thermolabile variant who, in the absence of relational stress, developed an erectile dysfunction (ED) refractory to the vasoactive type-V phosphodiesterase (PDE5) inhibitor therapy. After one month of treatment with 5 mg/day folic acid and 1000 microg/day cyanocobalamin, the patient restarted the assumption of 50 mg sildenafil, obtaining satisfying erections during sexual intercourse. We suggest that hyperhomocysteinemia may interfere with penile blood supply and, thus, be responsible for ED. If this relationship is confirmed, plasma levels and urinary homocysteine (HCy) should be evaluated in selected young patients with vascular ED. Furthermore, careful attention should be given to the risk of ED when dealing with this metabolic disturbance.

Relationship Between the Severity of Penile Curvature and the Presence of Comorbidities in Men With Peyronie's Disease

We investigated the relationship between penile curvature severity and co-morbidities in men with Peyronie's disease (PD) and assessed whether the severity of curvature had an impact on penile vascular status and/or erectile function. Based on a 10-year period 469 patients with PD were retrospectively evaluated in regard to age at diagnosis, type and degree of penile curvature, erectile dysfunction (ED) and other comorbidities, such as diabetes mellitus, hypertension, serum lipid abnormalities, smoking and ischemic heart disease. To assess penile vascular status all men with PD underwent penile duplex Doppler ultrasound evaluation. The severity of penile curvature was classified using the Kelami system, that is grade 1--curvature 30 degrees or less, grade 2--30 to 60 degrees and grade 3--greater than 60 degrees. Mean patient age was 54.8 +/- 4.3 years (range 18 to 79) and the mean duration of symptoms was 24.8 +/- 13.7 months (range 3 to 120). The most common penile abnormality was dorsal curvature in 47.1% of patients. The most frequently documented co-morbid conditions in association with PD were hypertension in 27.2% of cases, smoking in 25.5%, hypercholesterolemia in 18.3%, diabetes mellitus in 17.2%, hyperlipidemia in 15.7% and a history of penile trauma in 13.2%. There was no relationship between the number or severity of each of these co-morbid conditions and the severity of the penile abnormality. In addition, there was no relationship between the severity of penile curvature and penile vascular status in patients with PD. Moreover, the prevalence of these comorbidities, except smoking and penile trauma history, was significantly higher in patients with PD and concurrent ED than in patients with PD only. While co-morbid conditions, such as hypertension, smoking, hypercholesterolemia, diabetes mellitus and hyperlipidemia, are commonly seen in patients with PD and may seem to be risk factors for PD, there was no statistical relationship between penile curvature severity and any of these comorbidities. Similarly there was no statistically significant relationship between the severity of curvature and penile vascular status or ED. The fact that the prevalence of associated comorbidities is higher in patients with PD and ED than in patients with PD only indicates that these comorbidities are more likely related to ED than to the pathogenesis of PD.

Impaired brachial artery endothelium-dependent and -independent vasodilation in men with erectile dysfunction and no other clinical cardiovascular disease

ObjectivesThe goal of this study was to determine whether patients with vascular erectile dysfunction (ED) and no other clinical cardiovascular disease have structural and functional abnormalities of other vascular beds. BackgroundIn many ED patients, vascular disease is the major underlying cause. It may be that ED is an early marker of atherosclerosis in patients without clinical cardiovascular disease. MethodsWe assessed systemic vascular structure and function in 30 patients with ED and 27 age-matched normal control (NL) subjects. We measured vascular parameters, including: 1) carotid and brachial artery diameters, intima-media thickness, compliance, and distensibility; 2) aortic pulse wave velocity; 3) coronary calcification; and 4) brachial artery endothelium-dependent and -independent vasodilation. ResultsThere were no significant differences in baseline demographics, coronary artery risk score, or lipid values between the two groups. Most structural and functional vascular parameters were similar in the ED and NL groups. Brachial artery flow-mediated vasodilation (FMD) (1.3 vs. 2.4%, p = 0.014) and vasodilation to nitroglycerin (NTG) (13.0 vs. 17.8%, p < 0.05) were significantly reduced in ED patients, compared with NL subjects. In addition, there was a significant correlation between FMD and vasodilation to NTG in ED patients (r = 0.59, p < 0.05) but not in NL subjects. ConclusionsPatients with ED but no clinical cardiovascular disease have a peripheral vascular defect in endothelium-dependent and -independent vasodilation that occurs before the development of other overt functional or structural systemic vascular disease and is independent of other traditional cardiovascular risk factors.

Erectile dysfunction: symptom or disease?

Erectile dysfunction (ED) has been defined by the National Institute of Health (NIH) as the inability to achieve and/or to maintain an erection for a sufficiently long period of time so as to permit satisfactory sexual intercourse. ED affects millions of men throughout the world and could have a negative influence on the individual's well-being as well as on the quality of life of affected subjects. Discordant data have been reported on ED epidemiology with prevalence ranging from 12% to 52%, probably depending on the different criteria utilized in the different studies for patient selection. ED is a symptom, sometimes the first, of different pathological conditions. In 15.7% of 45-yr-old patients with vascular ED a dynamic ergometric test has shown electrocardiographic alterations in the absence of any cardiac symptom. In 15% of the patients with ED, high fasting glucose plasma levels are discovered for the first time and in patients with ED and normal fasting glucose plasma levels the prevalence of undiagnosed diabetes mellitus is 12.1% after an oral glucose tolerance test (OGTT). The different risk factors are often additive in the possible development of systemic vasculopathy, neuropathy and ED. ED, underestimated in clinical practice due to archaic prejudice which hinders the patient in spontaneously revealing the problem and the physicians in investigating it, can mark the point where evaluation and prevention of important diseases (such as diabetes, arterial hypertension, atherosclerosis) hitherto unknown by the patients, can begin. The physicians' cultural baggage must include the ability to identify the pathology that can determine ED and the ability to program a specific diagnostic workup. In this paper the different specialists involved in ED diagnosis agreed that a clinical approach which allows the identification of systemic pathologies contributing to the development of ED constitutes an improvement in disease prognosis and may either induce a spontaneous reduction of ED or facilitate its specific treatment.

Surgical management of erectile dysfunction.

Since the introduction of sildenafil citrate, oral systemic therapy has become the first line of therapy for men with erectile dysfunction (ED). Men who are not candidates for or who fail treatment with an oral agent may choose second-line therapies such as intraurethral prostaglandins, penile injection therapy, sex therapy, or a vacuum erection device. These secondline therapies may be unpalatable or inadequate for some men, and these men constitute the candidates for surgical intervention for ED. This article reviews surgical management of vascular ED, surgical management of Peyronie's disease, and penile prosthesis implantation. At the current time, the appropriate candidate for penile revascularization is a young man with proven arterial insufficiency resulting from pelvic trauma. Results in other populations are disappointing. Peyronie's disease with curvature significant enough to interfere with intercourse may be managed with tunical lengthening or shortening procedures in potent men and with prosthetic implantation in men with ED. Modern three-piece penile prostheses are associated with excellent device reliability, high rates of patient satisfaction, and acceptably low complication rates.

The Place of Surgery for Vascular Impotence in the Third Millennium

With the arrival of new oral therapies the question arises about the role of surgery in patients with vascular impotence. We compared the sexual satisfaction rate in patients with arterial and/or venous impotence treated with 4 surgical techniques with long-term followup. Surgery was performed in 130 patients with vascular erectile dysfunction by 1 surgeon. Two young patients (2%) with traumatic arterial lesions underwent penile revascularization (group 1), while 128 with arterial and/or venous impotence were also treated with surgery, including 11 of 130 (8%) with deep dorsal penile vein resection (group 2), 39 (30%) with arterialization of the deep dorsal penile vein (group 3) and 78 (60%) with penile implants (group 4). Sexual satisfaction, defined as the possibility of satisfactory sexual intercourse without any additional treatment or pain, was evaluated by patient interview. Of the 130 patients 111 (85%) participated in the sexual life events interview, including 2 of 2 (100%) in group 1, 7 of 11 (63.6%) in group 2, 33 of 39 (85%) in group 3 and 69 of 78 (88%) in group 4. Mean followup was 50, 48, 46 and 54 months for groups 1 to 4, respectively. The sexual satisfaction rate was 2 of 2 (100%) for penile revascularization, 1 of 7 (14%) for venous resection, 4 of 33 (12%) for arterialization and 64 of 69 (93%) for penile implantation. Complications occurred in 9.5%, 12.5% and 20.5% of the patients in groups 2 to 4, respectively. Except for young patients with traumatic arterial lesions this study demonstrated the poor sexual satisfaction rate in impotent patients treated with the vasculogenic approach and the high rate of satisfaction in those treated with penile implants. Better selection criteria must be applied for vascular surgical treatment for impotence.

Review: The vascular system and erectile dysfunction in diabetes — the role of penile Doppler

Diabetes is associated with an increased risk of Dvasculogenic erectile dysfunction due to arterial occlusive disease and impaired vascular smooth muscle relaxation. Doppler ultrasound of the cavernosal artery offers a functional evaluation of penile haemodynamics, in particular the accurate assessment of arterial insufficiency. The current role of penile Doppler testing in the assessment of diabetic patients with erectile dysfunction is reviewed.

Penile pharmacotesting in diagnosing male erectile dysfunction: evidence for lack of accuracy and specificity.

Penile pharmacotesting (PPT) with alprostadil (PGE1) represents the most common diagnostic approach to male erectile dysfunction (ED). A positive response - i.e. normal erectile rigidity of sustained duration - is presumed to exclude venous or arterial pathology with enough accuracy. To test this assumption we compared PPT vs. flowmetric results obtained by colour-duplex Doppler ultrasound (CDDU) in patients (pts) undergoing diagnostic evaluation for ED under conditions of maximal cavernous relaxation. A total of 195 non-consecutive impotent pts were diagnosed after dynamic CDDU as non-vasculogenic (NOR), or having arteriogenic (AR), veno-occlusive (VO) or mixed (MX) ED. Maximal erection obtained after PPT was scored as: type-1 (full tumescence - no sustained rigidity, angle on the abdominal plane >90 degrees), type-2 (sustained partial erection, valid for intromission, angle=90 degrees) and type-3 (sustained full erection, angle <90 degrees). Comparing PPT with flowmetric results, we found that a type-3 response had 20% false negative diagnosis of NOR (17% of AR- and 3% of VO- and MX-ED, respectively), while a type-2 response had 63% false negative diagnosis (20% of AR, 37% of VO- and 6% MX-ED, respectively). Type-1 response was associated with the presence of VO dysfunction in 99% of cases. These data suggest that a positive response to PPT (type-2 and type-3) assessed by the visual rating of erection is associated with both arterial (up to 20%) and/or VO (up to 43%) ED, as detected by CDDU. We conclude that PPT alone is a misleading diagnostic test to exclude vascular ED and that dynamic CDDU should be offered to pts investigated for male ED.

New concept parameters of RigiScan in differentiation of vascular erectile dysfunction: is it a useful test?

The aim of this study is to investigate the value of new nocturnal penile tumescence recording parameters, such as tumescence activity unit and rigidity activity unit values, total erection number and erection times, in differentiating between psychogenic erectile dysfunction and organic erectile dysfunction. We also aimed to determine the role of these parameters in differentiating arterial erectile dysfunction from veno-occlusive dysfunction. Eighty-seven consecutive patients were allocated into three groups as psychogenic, arterial and venous erectile dysfunction after investigations. Nocturnal penile tumescence recording parameters between psychogenic and vascular erectile dysfunction and arterial and veno-occlusive dysfunction were compared. Mann-Whitney U-test, Pearson's chi2 test and correlation coefficient tests were used for statistical analysis. Depending on intracavernous injection, penile Doppler ultrasonography and cavernosometry tests, 37 patients (43%) had psychogenic impotence while 50 (57%) had organic pathologies. Of the 50 patients diagnosed with vascular impotence, 29 (48%) had arterial failure and 21 (42%) had veno-occlusive dysfunction. Nocturnal penile tumescence recording revealed psychogenic erectile dysfunction in 34 patients (39%) and vascular erectile dysfunction in 53 patients (61%). Nocturnal penile tumescence recording has been regarded as the gold standard and, in our series, it showed 90.6% sensitivity and 88.2% specificity in differentiating the cause of erectile dysfunction. Values of rigidity activity unit and tumescence activity unit were significantly higher in patients with psychogenic impotence (P < 0.001), when compared with vascular impotence. In patients with a vascular cause, no difference was found between arterial failure and veno-occlusive dysfunction with regard to tip tumescence activity unit, base tumescence activity unit, tip rigidity activity unit, base rigidity activity unit and erection time (P > 0.001). However, patients with arterial failure had less erection than patients with veno-occlusive dysfunction (P < 0.001). New recording parameters of nocturnal penile tumescence can differentiate organic and psychogenic erectile dysfunction more precisely. However, these recording parameters cannot distinguish subgroups with a vascular cause of erectile dysfunction.

Sex inventories: can questionnaires replace erectile dysfunction testing?

Objectives. “Paper and pencil” sexual inventories are widely used by the pharmaceutical industry for categorizing the severity of erectile dysfunction (ED) and for efficacy end points of drug therapy. The International Index of Erectile Function (IIEF) evaluates several domains of male sexual behavior: erection, orgasm, desire, and satisfaction. We compared the subjective IIEF score for erectile function with the severity and etiology of ED as determined by pharmacologic testing with prostaglandin E 1 (PGE 1) and color duplex Doppler ultrasound testing (penile blood flow study [PBFS]). Methods. Five questions from the IIEF that require the patient to quantify his erectile performance were compared with PBFS data. Examiners were unaware of IIEF scores during testing. PBFSs were performed after PGE 1 injection, privacy, and self-stimulation; dosing was 6 μg (50 to 59 years) or 10 μg (60 years or older). PBFS diagnoses were arterial insufficiency (AI) for peak systolic velocity (PSV) less than 25 cm/s; cavernous venous occlusive disease (CVOD) for PSV greater than 35 cm/s and resistive index (RI) less than 0.9; and mixed vascular erectile dysfunction for a PSV from 25 to 35 cm/s and RI less than 0.9. A normal vascular diagnosis required a PSV greater than 35 cm/s and an RI of 0.9 or greater. Visual ratings of the erectile responses without Doppler assessment (inadequate, adequate, or excellent) were also compared with the IIEF and Viagra Study Group criteria (Q3+4). Results. Eighty-nine patients underwent the complete evaluation. Eight patients (9%) were found to be normal vascularly (mean PSV 40.9 cm/s, mean RI 0.99). Thirty-four patients (38%) had AI (mean PSV 17.5, mean RI 0.74), 33 patients (37%) had mixed vascular ED (mean PSV 29.1, mean RI 0.80), and 14 patients (16%) had CVOD (mean PSV 45.9, mean RI 0.73). The mean IIEF score for the normal responders was 13.3; patients with AI, mixed vascular ED, and CVOD had mean IIEF scores of 6.9, 8.5, and 8.1, respectively. IIEF and Q3+4 values differed significantly between the normal and abnormal groups ( P <0.05 and P <0.025, respectively), but no statistically significant differences in IIEF or Q3+4 scores were noted among the subgroups of abnormal responders. Analysis of the visual ratings of erections demonstrated that IIEF scores were significantly different between inadequate and excellent responders ( P <0.05). Conclusions. IIEF scores did not statistically differentiate among the specific etiologies of ED as determined by evidence-based testing with PBFS. Furthermore, patients with normal results after testing with PGE 1 (10 μg or less) had surprisingly low self-ratings of erectile performance (13 of 25 points). For the primary caregiver, the IIEF may help in the taking of the male sexual history, but for the specialist, sexual inventory scores will not distinguish among the various etiologies of vascular ED and do not predict the results of pharmacologic testing.

Diabetes and vascular impotence: does insulin dependence increase the relative severity?

Diabetes is a well documented risk factor for vascular erectile dysfunction (ED). We evaluated the relative roles of insulin dependence (IDDM) vs oral agent controlled diabetes (NIDDM) in predicting the etiologies and severity of ED: arterial insufficiency (AI), venous leakage (CVOD), and mixed vascular disease. The impact of additional risk factors were also analyzed: hypertension (HTN), coronary artery disease (CAD), and smoking (SM). Retrospective data on 105 patients complaining of impotence who underwent pharmacotesting with PGE1 (Caverject) and color duplex Doppler was reviewed. Penile blood flow study (PBFS) data following a period of privacy and self-stimulation was compared. PBFS diagnostic criteria were: AI for peak systolic velocity (PSV) < 25 cm/s; CVOD for PSV > or = 35 cm/s and resistive index (RI) < 0.9; mixed vascular disease for PSV > or = 25 cm/s, PSV < 35 cm/s and RI > 0.9. Consistent dosing of PGE1 was used; 6 mcg for age < 60 y and 10 mcg for age > or = 60 y. Patients were NIDDM (79 out of 105) and IDDM (26 out of 105). Mean ages for NIDDM and IDDM were respectively 60, and 55 y. The relative significance of insulin dependence was assessed by Student's t-test. The most common etiology of ED was arterial insufficiency: mean PSV's did not significantly vary and were: 23.5 cm/s for NIDDM, and 21.6 cm/s for IDDM. PBFS parameters did not vary significantly for the risk factors of SM or HTN and diabetes. Mean peak systolic velocities were significantly different among diabetics with coronary artery disease: NIDDM/CAD, 22.9 cm/s compared to IDDM/CAD, 14.8 cm/s (P = 0.006). We found among the 105 diabetics the most common etiology of vascular ED based on Doppler criteria was arterial insufficiency, 64%. Statistical analysis of additional risk factors (SM, HTN, CAD) suggested that patients with IDDM and CAD have more severe cavernosal arterial insufficiency than patients with NIDDM and CAD. This data tends to support the theory that microangiopathy is the predominant factor in diabetic impotence, and that insulin dependent diabetes with 'large vessel' coronary heart disease have a similar pathology in the 'small vessels' regulating penile inflow which is unfortunately worse than their non-insulin dependent counterparts.

A dose-response study of alprostadil in patients with erectile dysfunction

The efficacy and safety of alprostadil were investigated in this open-label study of 105 men with various etiologies of erectile dysfunction (ED). Initially, patients received an intracavernous injection of alprostadil 2.5 μg, with subsequent increases in dose until a full erection (lasting 30 to 60 minutes) was achieved or a dose of 40 μg was reached. Ninety-eight (96.1%) of the 102 patients who completed the study achieved a full erection. More patients with psychogenic ED (46.5%) versus those with vascular ED (4.0%) responded to a 2.5-μg dose. Penile pain was reported by 12 (11.4%) of 105 patients. There were no reports of erections lasting longer than 4 hours, penile hematoma, or penile abnormalities.