Intracavernous Injection Of Vasoactive Drugs Research Articles

Traitement de l'érection peropératoire par le bloc pénien

Erection during endoscopic or penile surgery is a troublesome event. In this case report, the erection was first treated with intracavernous injection of etilefrine (8 mg) and detumescence was obtained rapidly. However, one hour later, the erection occurred again. Therefore a dorsal penile nerve block was performed by the median route, using 8 mL of 0.25 % bupivacaine injected into the subpublic space. Mechanisms and treatments of intraoperative erections are discussed. Repeated intracavernous injections of vasoactive drugs may be dangerous, whereas a penile nerve block carries a lower risk of cardiovascular complications and provides an improved postoperative analgesia.

Role of cyclic adenosine monophosphate in prostaglandin E1-induced penile erection in rabbits.

To investigate the role of cyclic adenosine monophosphate (cAMP) in penile erection in relation to the effect of prostaglandin E1 (PGE1) male adult New Zealand white rabbits were utilized as a model to study intracavernous pressure (ICP) in vivo. After intracavernous injection of PGE1 (0.2-1.6 micrograms/kg) and 8-bromocyclic adenosine monophosphate (8-Br-cAMP, 0.5-1.5 mg/kg), both drugs raised the ICP in a dose-dependent manner. The increased ICPs induced by PGE1 and 8-Br-cAMP were 33.4 +/- 8.12 and 24.1 +/- 4.9 mm Hg, respectively (p < 0.05, paired Student's t test). Administrations of cyclic adenosine monophosphothioate, Rp-isomer (cAMP antagonist, 0.02-0.08 mumol/kg) prior to PGE1 injections inhibited the effect of PGE1 in vivo in a dose-dependent manner. The systemic blood pressures and heart rates in rabbits were unchanged during all the intracavernous injections. The corpus cavernosal tissues isolated from rabbits were studied for the cAMP contents after incubation of different doses of PGE1 in vitro. The cAMP contents were also elevated in a manner parallel with the increases in PGE1 concentrations (3-9 microM). We conclude: (1) the feasibility of intracavernous injection of vasoactive drugs is similar to that in man, thus the rabbit can be used as a suitable alternative for the studies of penile erection, and (2) cAMP is mediated in PGE1-induced relaxation of the rabbit corpus cavernosum, and the cAMP system only participates partially in penile erection.

Dose Evaluation Study of Alprostadil in Erectile Dysfunction

ABSTRACT: Intracavernous injection of vasoactive drugs is an important therapeutic advance for the treatment of erectile dysfunction. Namely three drugs used alone or in combination have gained clinical acceptance: papaverine, papaverine and phentolamine, and alprostadil.Since the first reports on the use of alprostadil in 1987, investigators of many countries published studies reporting the efficacy of alprostadil in inducing erections with tolerable local side‐effects. Based on his personal experience, methodology, and support to the patients who entered a self‐injection program, the author performed a formal dose evaluation study in 116 patients who self‐injected alprostadil for treatment of erectile dysfunction.Of the 296 patients seen during the years of 1988 to 1992 and who were eligible for self‐injection of alprostadil to maintain their capacity for intercourse, only 116 patients were entered in the selfinjection program. Their ages were between 27 and 69 years old (average 53). One hundred eleven (94.8%) have elected a dose equal or inferior to 20 mcg of alprostadil as the minimal dose producing complete and functional erections. The optimal dose range is decided for each patient based on his satisfaction and tolerance and includes erections of 1 to 2 hours long, without adverse systemic or local reactions. The side effects were minimal (16 cases = 13.78%). They were hematoma (12), prolonged erection (2), fibrosis with penile curvature (1), and dizziness (1). The results are similar to others related in previous literature.The author believes that intracavernous injection of vasoactive drugs is an important instrument to deal with impotence and alprostadil is the drug of choice for the self‐injection program. Longterm use of alprostadil and its effects, social acceptability, and its adoption by national health authorities are, according to the author, issues that need to be addressed.

The Audio Visual Sexual Stimulation (AVSS) Test in the Clinical Approach to Erectile Disorders

ABSTRACT: The Audio Visual Sexual Stimulation (AVSS) test represents a simple method to investigate impotence (Condra et al, 1991). It represents the most physiological and less invasive test that is able to induce an erectile response in the laboratory (Wagner et al, 1981). It does not require complicated tools and gives us much information concerning the nature of erectile disorders and also a first insight on the etiological causes (Virag, 1987). The patient is placed in a diagnostic room that should be sufficiently comfortable and watches an “erotic” videotape. The patient also uses earphones to stimulate the hearing and to be isolated from the ambient.A Rigiscan Is applied to obtain a real‐time recording of the erectile response elicited by the AVSS (Pozza et al, 1990). The same procedure is utilized performing the AVSS after intracavemous Injection (ICI) test if the induced erection is not completely rigid.We can have four different responses to AVSS: (1) completely negative or absent response with a fiat tracing on Rigiscan, (2) feeble erectile activity when the Rigiscan shows erectile activity with rigidity of less than 50%, (3) moderate or fair activity if the erection is between 50 and 70% in rigidity, (4) good response when the patient gets an erection with rigidity above 70%.We can also obtain an erectile response characterized by moderate to good but of very brief duration. That means that there is a loss of rigidity during the blank periods of the AVSS.A group of 250 patients complaining of erectile disorders was investigated. The relationships with intracavernous injection of vasoactive drugs and conclusive diagnosis were evaluated.Good responses exclude the presence of relevant organic disease. Negative responses to the AVSS test could be due to relevant organic disease but also to cultural, social, and angiogenic factors. Feeble or moderate responses are considered to be related to organic factors and require other investigations. The presence of alternating erections is independent from the degree of penile rigidity. This pattern is very frequent in patients affected by venogenic impotence. Only 10 psychogenic patients (14.2%) showed feeble response compared to 42 arteriogenic (46.1%) and 19 venogenic ones (40.4%). A good response was observed in 13 venogenic patients (27.6%) even if with alternating erections. It was also observed in seven arteriogenic (7.7%), whereas it was present in 22 psychogenic patients (31.4%). Actually, we found that a feeble erection was associated with organicity in 84.8% of cases (73 out of 86), and a good one was associated with psychogenic causes in 37.5% (15 out of 40).A particular group of patients is that affected by corporal venoocclusive dysfunction (CVOD). Many of these patients show a peculiar erectile response characterized by good, complete erections during the AVSS with sudden decrease of rigidity during the blank periods of the video. Many patients (41 out of 54 cases: 75.9%) with such erectile response showed CVOD, which was confirmed by dynamic cavernometry. The AVSS represents the ideal test in the diagnostic approach to erectile disorders also because it is simple, cheap, and not invasive. The test could represent an acceptable diagnostic tool for those patients who refuse the ICI test or who have diseases that make the ICI dangerous (coagulation problems, hemodialysis, etc.).

Assessment of blood flow in different segments of the penis by duplex sonography in subjects with normal erectile potency

Correct evaluation of erectile potency requires careful assessment of the hemodynamics of the cavernous area. Pulsed Doppler flow velocity measurement of cavernous arteries after intracavernous injection of vasoactive drugs represents an effective, repeatable and minimally invasive technique. However, doubts remain concerning the procedures employed and the results obtained. Based on the assumption that all flowing viscous fluids are subjected to a significant decrease in pressure and, hence, velocity the smaller the vessel diameter is, the pulsed Doppler flow velocity measurement was used to evaluate such a decrease in three consecutive segments of the penis (a, b and c). A statistically significant decrease in velocity ( P < 0.0001 on the right and left) was observed between the arterial segments a, b and c in cavernous arteries of subjects with normal erectile function. Therefore, we stress that in the vascular evaluation of the penis, one should take into account the values obtained in each penile segment because a reduction in flow velocity in a proximo-distal direction can be regarded as physiologic. Misinterpretation of results can thus be prevented, avoiding a wrong diagnosis of arteriogenic erectile insufficiency.

Predictive Value of Real-Time Rigiscan Monitoring for the Etiology of Organogenic Impotence

We performed routine diagnostic evaluations in 160 consecutive patients from our impotence clinic. After the diagnostic studies were completed, the results of RigiScan**Dacomed, Minneapolis, Minnesota. monitoring during visual sexual stimulation before and after intracavernous injection of vasoactive drugs were compared to the results of standardized pharmacological testing, single potential analysis of cavernous electrical activity and pharmacocavernosometry. The results suggest RigiScan monitoring to be a highly accurate method to evaluate and document objectively the erectile response after intracavernous injection of vasoactive drugs. Although pathological monitoring after intracavernous injection is significantly associated with pathological findings in the specific evaluation, the predictive value of RigiScan monitoring for specific organogenic etiologies is not satisfactory, since normal monitoring showed no convincing correlation to single potential analysis of cavernous electrical activity or cavernosometry.

Venous Leaks: Anatomical and Physiological Observations

A total of 50 patients with impotence underwent cavernosometry and cavernosography with intracavernous injection of vasoactive drugs. Several hemodynamic parameters were analyzed, including the pressure response curve after injection of vasoactive drugs and infusion of saline, the volume required to achieve erection, venous outflow resistance, erection maintenance infusion rate, rate of pressure decrease after discontinuation of infusion and post-infusion steady state pressure.On the basis of cavernosometric findings, venous leakage was ruled out in 4 patients. In the remaining 46 patients leak sites visualized during cavernosography included superficial dorsal vein in 1 (2.2%), deep dorsal vein in all 46 (100%), cavernous veins in 32 (69.6%), glans in 19 (41.3%) and corpus spongiosum in 14 (30.4%). Aberrant veins were documented in 7 patients (15.2%) communicating with the saphenous vein in 4 (8.9%), scrotal veins in 2 (4.4%) and femoral veins in 1 (2.2%). Eight patients (17.4%) had leakage through the deep dorsal vein as the only venous site, 17 (36.9%) had leakage through 2 venous sites, 14 (30.4%) had leakage through 3 venous sites and 7 (15.2%) had leakage through 4 venous sites.Correlations among hemodynamic and radiographic observations allowed the identification of 4 different types of cavernosometric findings. While type I represented normal penile vascular findings, types III and IV represented venous leakage. Type II could represent no leak, a mild leak or an undetected arterial problem. Accuracy of interpretation of a study may be improved by taking more than 1 parameter into consideration, including erection maintenance infusion rate, intracavernous pressure decrease within the first 5 seconds after discontinuation of infusion and the final steady state intracavernous pressure. The majority of patients have more than 1 leak site (82.6%). The most commonly combined sites of leakage are the deep dorsal and cavernous veins.

Pharmacologically Induced Erections Among Geriatric Men

Intracavernous injection of vasoactive drugs for the treatment of erectile impotence has become a standard therapeutic technique. Previous reports detailing experience with this treatment are based on patient populations significantly younger than most patients who suffer from impotence. The geriatric population, which comprises the majority of patients with impotence, is unique due to the physical, psychological and social changes associated with the aging process. To characterize better elderly men with impotence, and determine whether intracavernous injection therapy is safe and effective in this age group, a retrospective analysis was performed upon patients attending the male sexual dysfunction clinic at our university medical center who received a standard papaverine and phentolamine mixture (30mg. papaverine and 1.0mg. phentolamine per ml.). The etiology of impotence, degree of patient satisfaction and complication rate of 65 patients 65 years or older (mean age 70 years) undergoing papaverine plus phentolamine self-injection therapy were compared to a similar sized group of impotent men approximately 20 years younger (mean age 47 years). Significant differences in etiology of impotence were evident between the 2 groups. Treatment response rates were equal for the 2 age groups although elderly patients required a higher dose of papaverine and phentolamine to obtain an erection, and used the medication less frequently. Complications were few, of minimal consequence and occurred with equal frequency between the 2 age groups.

Simplified Tourniquet for Intracavernous Pharmacotherapy

A simplified tourniquet, the Barretta Laso, is described for use during intracavernous injection of vasoactive drugs. The advantages of this device over current tourniquet methods include simple application; easy control of the degree of constriction; and quick, single-handed release.

Vacuum Constriction Device for Management of Erectile Impotence

A mechanical device for treatment of impotence based on the concept of entrapment of blood in the penis following vacuum-assisted tumescence is described and more than 15,000 units have been marketed. A total of 1,517 users who acquired the device between 1974 and 1987 completed a questionnaire concerning the system. Of these patients 92 per cent either achieved an erection or an erection-like state that was satisfactory for intercourse and 77 per cent had intercourse at least every 2 weeks. No serious ill effect from use of the device has been reported and it is particularly effective in the management of partial impotence. In selected patients the device is an alternative to either surgical placement of a penile prosthesis, intracavernous injection of vasoactive drugs or sexual abstinence.

Incidence, pathophysiology and treatment of prolonged erections

Prolonged erections (pharmacologically induced erections over 6 hours) are the most inconvenient side effects encountered in the diagnosis and therapy of erectile dysfunction with intracavernous injection of vasoactive drugs. Out of a total of 29 prolonged erections, 26 were seen after diagnostic use in 300 patients and 3 after therapeutic application in more than 4800 protocolled autoinjection of a standardized vasoactive solution (papaverine hydrochloride 15 mg/ml and phentolamine mesylate 0.5 mg/ml). In 25 of these 29 prolonged erections intracavernous injections of the alpha-receptor stimulant metaraminol was done and led to flaccidity in all cases. Another patient with a papaverine-induced erection lasting 26 h did not respond to intracavernous metaraminol and required puncture and aspiration; he lost spontaneous erectability and cavernosal response to vasoactive drugs. Metaraminol was also injected intracavernosally in a further 32 patients with pharmacologically induced full erections: flaccidity was obtained in all patients.

Intracavernous injection of vasoactive drugs in the rabbit.

To investigate the erectile response and side effects of intracavernous injection of vasoactive agents, 7 groups of 5 rabbits each underwent injection of either isotonic saline or 1 of 6 drugs. Phentolamine most consistently produced full erection with few inflammatory reactions, while phenoxybenzamine produced erection but also severe inflammation and sclerosis of the corpus cavernosum. With prostaglandin E1, neither erection nor inflammation was observed.

Evaluation of Vasculogenic Impotence

Penodynamics, the functional evaluation of erection after intracavernous injection of vasoactive drugs, is a simple screening test that excludes significant vascular problems if full erection occurs within a reasonable period of time. Although it is more invasive than the penile brachial index (PBI), it is well tolerated and easy to perform. There is good evidence that studies on the flaccid penis are less accurate and do not correlate well with the results of functional papaverine testing. To evaluate arteriogenic impotence, sonography and pulsed Doppler analysis combined with papaverine injections provide objective and reproducible measurements of diameter increase and blood flow of each penile artery and have the advantage of being a functional study. Although this equipment is expensive, it is available in many centers where noninvasive vascular flow studies are performed. With training, the technique can be mastered by anyone. The arterial response to papaverine and the resulting erection allow indirect judgment about the venous system. Therefore, the whole penile vasculature can be evaluated with this technique. Currently, many drugs or drug combinations are used to induce artificial erection, not only for diagnosis but also as a therapeutic alternative to penile prostheses. The only physiologic agent is prostaglandin E1, a substance that seems to be as effective as papaverine but can be metabolized within the cavernous tissue and reportedly results in fewer incidences of prolonged erection and priapism. The use of vasoactive drugs is also very helpful for angiographic studies by improving flow and diameter of the penile vessels, which will result in better images of the arterial lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Intracavernous injection of vasoactive drugs, an alternative for treating impotence in spinal cord injury patients.

We report on our results with the intracavernous injection and self-injection of papaverine-phentolamine in a group of spinal cord injury patients with erectile impotence. This technique offers the possibility of achieving a full erection which continues for a few hours and disappears afterwards. In our limited experience no major complications have occurred. If our findings are confirmed, in future, the self-injection technique may become a valuable alternative to implanting a prosthesis in impotent paraplegics and tetraplegics.