Enhancement of erectile responses to vasoactive drugs by a variable amplitude oscillation device.

The limitations of intracavernosal injection (ICI) of vaso-active drugs as a diagnostic tool in the evaluation of erectile dysfunction are well recognized and, prominently, include the artifacts induced by the unfamiliar environment on the patient. We report on the benefits of adding a vibratory stimulus to ICI to improve the sensitivity of this test in a population of 170 patients with erectile dysfunction who were evaluated using a standard protocol. Intracavernosal pressure was measured following ICI alone and ICI with vibratory stimulation of the penis. A statistically significant improvement in intracavernosal pressure (ICP) with the addition of vibration was observed in 87% of the subjects as compared to ICI. In 52% the improvement in ICP was greater than 20% over that achieved by ICI. This study showed that the addition of vibration to intracavernosal administration of vaso-active drugs significantly increases the erectile response in a controlled and reproducible manner. Vibratory stimulation provides a better reflection of erectile potential than the pharmacological challenge alone.

Surgical treatment of penile veno-occlusive dysfunction: is it justified?

OBJECTIVES: Veno-occlusive dysfunction is a commonly diagnosed cause of impotence. Surgical removal of the intermediate (deep dorsal vein and its tributaries) venous system of the penis has been advocated as an effective treatment but recurrence of the dysfunction is common after a few months. We studied prospectively the first 100 cases of veno-occlusive dysfunction undergoing surgical treatment at our institutions. METHODS: One hundred consecutive patients undergoing penile venous ligation surgery were evaluated. All patients had a comprehensive workup prior to therapy. Surgery involved excision of the intermediate venous drainage. Short-term results were investigated by personal interview, and long-term outcome was determined by separate telephone interview of patients and their partners when available. RESULTS: Short-term success (3 months) was 62%, and long-term success (45 months) was 31%. Historical factors, preoperative testing results, and histologic assessment of the surgical specimens were not found to be helpful in predicting outcome. CONCLUSIONS: Despite the mediocre long-term results of the surgical procedure and lack of preoperative predictive factors, we believe that venous leak surgery could be offered to well-selected patients in whom the only other available alternative would be a prosthetic device.

Diurnal penile tumescence recording in the etiological diagnosis of erectile dysfunction.

Rapid eye movement sleep occurs during napping. We investigated the appearance of penile tumescence during periods of day napping in a population of 18 impotent men who, in addition, underwent a comprehensive sleep investigation for impotence, including polysomnographic recording and nocturnal penile tumescence monitoring. Of the subjects 16 (88%) had rapid eye movement sleep during the night. Four patients who did not have erections on 2 separate sessions of nocturnal sleep recording also did not experience penile tumescence during the day. Of the 12 patients with documented erections at night 9 (75%) also exhibited erectile episodes during napping. Diurnal penile tumescence recording is less cumbersome, less expensive and more convenient to perform than its nocturnal counterpart. Diurnal penile tumescence appears to be a summary reflection of nocturnal penile tumescence episodes. The consistency between nocturnal and diurnal penile tumescence suggests that further study of this new technique is worthwhile. Validation of diurnal penile tumescence may offer a viable alternative to the comprehensive assessment of impotent men.

Topical glyceryltrinitrate causes measurable penile arterial dilation in impotent men.

The current understanding of the intracavernous changes that cause or accompany penile erections has encouraged the use of vasodilators as therapy for erectile dysfunction. An established vasodilator, glyceryltrinitrate, was selected for in vivo study because of its rapid transdermal absorption. Color coded duplex ultrasound was used to assess penile vascular response. In a large group of men with erectile dysfunction significant dilation was noted in response to a small amount of nitroglycerine paste applied to the penis. There is a measurable vasodilatory response that can be induced by synthetic nitrates in penile tissue in impotent men.

Topical nitroglycerin: a potential treatment for impotence.

The effect of 2 per cent nitroglycerin paste applied to the penile shaft of impotent subjects was evaluated in a placebo controlled double-blind study under laboratory conditions. After application of nitroglycerin paste or a placebo ointment base, penile tumescence was recorded through a strain gauge transducer while subjects viewed an erotic video presentation. Relative to the placebo paste the number of subjects demonstrating an increase in penile circumference after nitroglycerin (18 of 26) was significantly different than all other outcome possibilities (p less than 0.05). Noninvasive vascular assessment by ultrasonography demonstrated an increase in diameter and blood flow in the cavernous arteries after application of nitroglycerin paste. Nitroglycerin paste increases blood flow in the cavernous arteries and improves tumescence after erotic stimulation. This agent may represent a new therapy for impotence.

Oral and transcutaneous pharmacologic agents in the treatment of impotence.

The pharmacologic treatment of erectile failure is now a reality. However, current agents have major drawbacks. Some require invasive administration, whereas others offer only marginal effect. The use of hormones should be limited to well-documented cases of endocrine dysfunction. Oral and transcutaneous agents remain experimental, but new drugs are under investigation and show early encouraging results.

Double-blind trial of yohimbine in treatment of psychogenic impotence.

48 subjects meeting strict diagnostic criteria for psychogenic impotence took part in a 10 week placebo-controlled, double-blind, partial crossover trial of yohimbine (18 mg a day) for restoring erectile function. At the end of the first arm of the trial 62% of the yohimbine group and 16% of the placebo group reported some improvement in sexual function (chi 2 = 10.41, df = 2, p less than 0.05). 21% of the originally placebo-treated group noticed some improvement over pre-treatment levels when they were put on yohimbine in the second arm of the trial. Overall 46% of those who received yohimbine reported a positive response to the drug, a response rate very similar to that observed in a previous study of patients with organic impotence. Response to yohimbine thus seems to be unrelated to current groupings of the cause of impotence. Yohimbine is a safe treatment for psychogenic impotence that seems to be as effective as sex and marital therapy for restoring satisfactory sexual functioning.

Is yohimbine effective in the treatment of organic impotence? Results of a controlled trial.

Yohimbine is an alpha-adrenoceptor blocker that has been used in the treatment of erectile dysfunction. Adequate trials of this substance in a clearly defined organically impotent population are not available. We conducted a randomized, controlled study with partial cross-over of yohimbine versus placebo in 100 organically impotent men. The first phase of the study showed a positive response in 42.6 per cent of the patients receiving yohimbine versus 27.6 per cent in the placebo group. Although favorable to the test medication these values did not reach statistical significance (p equals 0.42). A similar pattern was noted in the second phase of the study. The over-all response rate of 43.5 per cent was consistent with a previous noncontrolled trial but it was much lower than previous studies. The response rate of organically impotent patients to yohimbine is at best marginal. Owing to its ease of administration, safety and modest effect it still is used in those patients who do not accept more invasive methods. Adrenoceptors are involved in the erectile process, although other neurotransmitter systems also are putative modulators of penile erection, including cholinergic, dopaminergic and vasoactive intestinal polypeptide pathways. It is beyond reasonable expectation that a single agent be of value for all cases of organic impotence. However, yohimbine has shown modest effectiveness at the doses used in this trial (18 mg. per day). Higher doses or a different route of administration may produce different effects.

Screening assessment of penile tumescence and rigidity. Clinical test of Snap-Gauge.

A study was conducted to investigate the clinical usefulness of the Snap-Gauge, a device intended to provide an economical alternative to complete nocturnal penile tumescence (NPT) recording. Twenty-one patients were assessed using the Snap-Gauge either during NPT recording or during the corporeal calibration test (CCT), or both. Patient acceptance of the device was excellent. The results indicate a fair degree of consistency between the Snap-Gauge and CCT measurements. The Snap-Gauge and NPT findings were less consistent. The results suggest that the Snap-Gauge is a reliable and useful screening device for assessing impotent patients. However, it is not an adequate substitute for a more complete NPT monitoring with polysomnographic recording.

The pharmacokinetics of yohimbine in man.

The kinetic disposition of yohimbine was examined in eight young male subjects following a single oral dose of 10 mg yohimbine hydrochloride. The drug was rapidly absorbed (absorption half-time 0.17 +/- 0.11 h) and rapidly eliminated from the plasma (elimination half-life 0.60 +/- 0.26 h). This clearance of yohimbine from plasma was constant over approximately 10 elimination half-lives, suggesting that distribution into a second pharmacokinetically distinct compartment was not responsible for the rapid decline in plasma yohimbine levels. Urinary excretion and the partitioning of the drug into red blood cells (RBC) was investigated. In the 24 h following oral administration of the drug, virtually no yohimbine was eliminated in the urine (0.35 +/- 0.50% of the administered dose). Furthermore, only 20% of blood-borne yohimbine was located in RBC. These results suggest that yohimbine is eliminated primarily through metabolism since the rapid plasma clearance of yohimbine was not the result of renal elimination or sequestration by RBC.

Prevalence and significance of tobacco smoking in impotence.

We investigated the incidence of cigarette smoking in a sample of patients and compared these figures with estimates of smoking among males in the general population. Among 178 impotent patients the number of current smokers (58.4%) and current ex-smokers combined (81%) was significantly higher than would be expected among males in the general population. In each age group, and at all levels of tobacco use, impotent patients smoked more than would be expected from population estimates. Smoking and nonsmoking impotent patients did not differ in terms of their hormonal profile; however, mean penile blood pressure (PBI) was lower among patients who smoked than among those who did not. A significantly higher proportion (20.9%) of impotent patients with a history of smoking showed abnormally low PBI compared with nonsmoking patients (8.8%). This study adds to preliminary evidence that smoking may be a significant risk factor in impotence, and its effects are evident in the small vasculature.

The unreliability of nocturnal penile tumescence recording as an outcome measurement in the treatment of organic impotence.

We investigated the degree of congruence between outcome measures used to evaluate pharmacological treatment of impotence. After a comprehensive multidisciplinary assessment 17 patients were treated with an adrenergic blocker during an 8-week interval. Nocturnal penile tumescence recordings were made before treatment (as part of the assessment procedure) and at its conclusion. As part of a larger study the use of nocturnal penile tumescence monitoring has been examined as a possible outcome measure. Patient and partner self-reports also were used to evaluate treatment outcome. A comparison of patient and partner self-reports with nocturnal penile tumescence records showed little agreement between the 2 measures. These findings suggest that despite its intuitive appeal as an index of erectile function nocturnal penile tumescence recording is not a reliable index of therapeutic effectiveness. Furthermore, these findings lend support to the hypothesis that nocturnal penile tumescence and sexual erections may be separate phenomena, perhaps under the control of different mechanisms.

Sub-nanogram analysis of yohimbine and related compounds by high-performance liquid chromatography.

A sensitive (50 pg/ml) method is described for the analysis of yohimbine in blood by high-performance liquid chromatography with fluorescence detection. The chromatographic behaviour of eserine (employed as internal standard), reserpine, corynanthine, yohimbinic acid, and yohimbine are examined on a series of reversed-phase and normal-phase chromatographic columns with methanol-water mobile phases.

Endocrine dysfunction in impotence: incidence, significance and cost-effective screening.

A comprehensive evaluation of impotence includes assessment of the functional integrity of the hypothalamic-pituitary-gonadal axis. However, little is known about the incidence or significance of hormonal abnormalities in an unselected group of men with erectile failure. A systematic multidisciplinary, multidimensional assessment of 256 impotent men showed clearly an organic etiology in 35.9 per cent, psychogenic in 38.3 per cent and mixed or uncertain in 25.8 per cent. The incidence of hypothalamic-pituitary-gonadal axis abnormalities in the entire group was 17.5 per cent but in only 12.1 per cent did they contribute clearly to erectile dysfunction. A cost-effective screening of the endocrine system in impotent men includes a thorough history and physical examination, and a serum testosterone determination. More sophisticated and expensive investigations should be reserved for patients with a history of drug use known to induce hormonal abnormalities or with somatic evidence of hypogonadism and a depressed serum testosterone level.

Evaluation of the urological assessment in impotence: findings with a new diagnostic rating scale.

We report the findings of a critical evaluation of urological assessment in impotence. Initially, a rating scale (Q scale) was developed, which included the individual elements of the urological assessment, such as testicular size, serum testosterone level and so forth. The items in the scale were derived from the files of patients with erectile dysfunction and were scaled according to predetermined categories. Following this, the rating scale was applied to 67 impotent patients in whom the etiology had been established clearly using criteria that were independent of the urological assessment (that is a psychiatric interview and nocturnal penile tumescence evaluation). Statistical analysis of the results indicated that the 2 diagnostic groups differed significantly on a number of the individual scale items. However, no single item by itself could be used as a reliable indicator of etiology. Further analysis indicated that when the items were considered in combination, rather than singly, etiology was identified correctly in 95 per cent of the patients in the sample. Replication of these findings in a cross-validation study will help to standardize the urological assessment and to promote the development of a common language to facilitate communication in this field.

Nocturnal penile tumescence with stamps: a comparative study under sleep laboratory conditions.

The usefulness of nocturnal penile tumescence with stamps to measure erections during sleep has been evaluated under laboratory conditions and compared to strain gauge recording. If the ring of stamps does not break a diagnosis of organic dysfunction is supported. However, if breakage occurs at the perforations no diagnostic conclusion can be made. The diagnostic importance of nocturnal penile tumescence with stamps is limited.

A new device for diagnostic screening of nocturnal penile tumescence.

An erectometer for the measurement of sleep erections is described. Comparative studies using simultaneously strain gauges and the new device indicate that it possesses a significant potential for valid measurement of the circumferential increase that may occur during sleep. Because of its reliability, simplicity and low cost the erectometer is proposed as a screening procedure or as a diagnostic alternative when sleep laboratory facilities are not feasible.

Dysfunction of the detrusor and urethra in multiple sclerosis: the role of drug therapy.

Urinary tract disorders secondary to multiple sclerosis are common. In this series of 24 patients with multiple sclerosis, 5 had normal function of the detrusor, 3 had detrusor hypotonicity and 16 had detrusor hyperreflexia. The proximal urethra was evaluated using radiologic and electromyographic techniques. These studies showed that 5 patients had a normal urethra, 15 had some degree of somatic dyssynergia and 3 had sympathetic dyssynergia. Detrusor hyperreflexia with somatic dyssynergia was found in 11 patients and was the most common pattern. The therapeutic response to standard pharmacologic preparations was also evaluated. The regimen was based on the clinical and urodynamic findings for each patient. Dicyclomine hydrochloride was the drug of choice for detrusor hyperreflexia, bethanechol chloride for hypotonicity, dantrolene sodium for somatic dyssynergia and phenoxybenzamine hydrochloride for sympathetic dyssynergia. The authors found that most of their patients were amenable to drug therapy, the exception being those with advanced neurologic lesions.