Biomedical subjects
Publications and source records attributed to R Virag.
A multidisciplinary approach with emphasis on hemodynamic tests was used to diagnose 421 patients with arteriogenic, venogenic or mixed arteriogenic/venogenic impotence who underwent a vascular surgical procedure. With an average follow-up of nearly five years, approximately 50% of patients were cured and an additional 20% were improved.
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A very large amount of human material (7 embryos, 12 stillborns, 12 penes of males aged between 2 and 86 years, as well as bioptical material from 80 subjects affected by impotence problems) has been examined so as to study the penis arterial and venous walls, the blood flow regulation mechanisms and the intracavernal trabecular morphology. The amount of muscle tissue and of collagenous connective tissue has been numerically quantified by computer-assisted methods. This study enables the authors to underline three fundamental facts: (a) it confirms the normal penile erection mechanism, and the consequent theory, (b) it confirms that vascular sclerosis is a systemic phenomenon correlated to age, and that the penis is not exempt, and (c) in the case of impotence problems, the same sclerosis phenomenon may appear at an earlier age, and therefore induce pathological impotence.
Between 1977 and 1986, 3,500 patients were examined for the symptom of impotence; 1,250 of them received multidisciplinary investigation permitting the diagnosis of a pure organic or mixed disorder in 85% of cases, including 62% of vascular disease subdivided into arterial (40%) and venous (22%). For 1,062 patients, 1 or several of the following therapies were used: intracavernous infusion of vasoactive drugs (N = 725), auto-injections (N = 235), vascular surgery (N = 357) and prostheses (N = 23). The diagnostic approach, formerly analytical and making use of multiple non-invasive methods, such as nocturnal erection plethysmography (NPT) and invasive methods (artificial erection, arteriography) have been transformed by the use of pharmacological tests associated with visual sexual stimulation (VSS) which enable, together with Doppler velocimetric examination, simple screening of vascular impotence based on the study of 4 parameters: penile pressure index (PPI) when less than 0.91 is always a sign of an arterial problem, the severity of which is directly proportional to the lowering of this index and the association with maintenance insufficiency; the initial intracavernous flow rate (IICF) depends overall on the maintenance flow and the state of erectile tissue, resulting from pharmacological stimulation by a low dose of papaverine (8 mg); penile rigidity attained by the combined action of pharmacological and visual sexual stimulation, reflecting the functional erectile capacity; the duration of the rigidity thus obtained on stoppage of VSS indicating the capacity for maintenance of erection. In the event of suspicion of an isolated venous leak or in association with arterial problems, it is the artificial erection with cavernosography, carried out after pharmacological stimulation, which enables the severity of the leak to be assessed. The following specific investigations are carried out to investigate a specific associated etiology: electromyogram for neurological disorders, hormone assay for endocrine disorders and psychological study using the MMPI questionnaire (Multiphasic Minnesota Personality Inventory). One can thus distinguish several groups of patients suffering from vascular impotence depending on the degree of arterial involvement: minor (PPI between 0.75 and 0.9), moderate (PPI between 0.65 and 0.75) and severe (PPI less than 0.65); depending on the degree of venous leaking: absent (MI less than 0.3 and/or MF less than 25 ml/min), minor (MI between 0.3 and 0.5 and MF between 30 and 50 ml/min), moderate (MI between 0.5 and 75 ml/min) and severe (MI greater than 0.75 and/or MF greater than 75 ml/mn).(ABSTRACT TRUNCATED AT 400 WORDS)
The discovery of the papaverine erection test by Virag in 1982 stimulated the interest of research workers in the physiology of the penis. Since then, the scheme of functioning proposed by Conti [Acta anat. 14:217-262, 1952] in 1952 has been frequently cited in the literature, although its finalism is evident. It is based upon the presence of regulatory mechanisms along penile arteries, veins and arteriovenous anastomoses. In spite of the fact that these anastomoses were unanimously admitted, recently the presence of arterial and venous cushions has been controverted or even denied. Before attempting any functional explanation using nerves and chemical mediators, we made sure first of the concrete material reality of these anatomical structures. Thirty-five years after the main study, the present observations confirm the morphologic descriptions made in 1952. The contrary would have been astonishing. In fact, arterial and venous cushions were demonstrated by the School of Anatomy of Padova, the most ancient and venerable of all (Fallope, 1550), then by other institutes of morphology that dealt with these cushions in practically all the organs of the human body. It remains to establish their role in erection - whether it is null, complementary or primordial: that is the question.
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The main non invasive test to quantify arteriogenic impotence is the penile blood pressure (P.B.P.I.). However, its signification is still in discussion. In this work, after discussion of the previous literature, we have revisited the P.B.P.I. signification by quoting it in comparison to the dynamic tests of erection (artificial erection, papaverine test, nocturnal penile tumescence (N.P.T.) with the findings of arteriography. A series of 51 cases having been studied with the multidisciplinary evaluation that we recommend were analyzed and compared to the location of the arterial lesions (aorto-iliac and/or internal pudendal) and to the response to the 80 mg papaverine test (rigidity and initial intracavernous flow (I.I.F.). A significant difference (p less than 0.05) for P.B.P.I. has been demonstrated between normal arteriograms and bilateral lesions. The P.B.P.I. is significantly lower when the lesions are located to the main arteries and bilateral. I.I.F. helps to differentiate hemodynamically severe arterial lesions where surgery is recommended from mild lesions where intracavernous drugs are first proposed. After discussion of the risks of the 80 mg papaverine test in unspecialized units, the authors propose a standardized method to evaluate the penile arteries, using the Doppler and the 8 mg papaverine mini-test which does not carry the risks of prolonged erection. This approach allows a precise morphologic and hemodynamic evaluation for the arterial impotence.
The length and the proximal and distal circumferences of the flaccid and erect penis were measured as part of the aetiological investigation of 62 impotent patients. These measurements, compared with the quantitative study of penile rigidity, demonstrate the lack of correlation between circumference changes and rigidity and constitute a simple method for the measurement of penile volume variations and, when compared with penile rigidity, provide important information concerning the physiology of erection and its dysfunction.
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The distribution of four main arterial risk factors (ARF) (diabetes, smoking, hyperlipidaemia (HLP), and hypertension) was investigated in 440 impotent men (mean age 46.8) in whom the penile blood-pressure index (PBPI) (ie, the ratio of the lowest systolic pressure in one of the four main arteries of the penis to the systolic pressure in the arm) was measured. In 222 the cause (organic or functional) of impotence was sought by further investigations, such as cavernosonography. 80% of this subgroup had organic impairment of erection. In 53% of these there was evidence of an arterial lesion. Smoking (64%), diabetes (30%), and HLP (34%) were all significantly more common in the 440 impotent men than in the general male population of a similar age. Whenever two or more ARFs were present mean PBPI was significantly lower. The frequency of organic impotence increased from 49% in the absence of any ARF to 100% in patients with 3 or 4 ARFs. It is concluded that increase in the frequency of impotence with age is mainly related to arteriosclerotic changes for the arteries of the penis and that the ARF and PBPI should be evaluated first in any patient complaining of impotence.
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Concentrations of vasoactive intestinal polypeptide were measured in blood drawn from the cavernous spaces of corpus cavernosum of the human penis during tumescence and erection, and the effect of injecting the polypeptide into the cavernous spaces was studied. A significant release of the polypeptide was shown during tumescence and erection. Injection of exogenous vasoactive intestinal polypeptide induced erection. These findings support the concept of vasoactive intestinal polypeptide as a neurotransmitter in penile erection and suggest that it might have a clinical use in patients suffering from erectile dysfunction.
The use of artificial erection (AE) for the diagnosis and treatment of erectile failure was studied in 180 impotent males selected from a group of 440 men who underwent a complete multidisciplinary approach including nocturnal penile tumescence (NPT), arterial, neurologic, hormonal, and psychologic studies. Five groups were identified: (1) nonorganic (15.3%) impotence considered as a control group for AE normal values; (2) arterial (26.6%); (3) neurologic (12.2%); (4) arterial and neurologic (19.4%); and (5) a group of 47 remaining patients (26.1%) with abnormal NPT and normal arterial and neurologic studies who had the highest flow to obtain and maintain erection and were classified as "venous incompetence." Results of AE flows of patients of groups 2, 3, 4, and 5 are presented and discussed in the focus of erectile physiology, pathophysiology of erectile failure, and surgery. Patients of groups 2 and 4 with normal flows had a 26.6 per cent rate of improvement due to AE. Results and comments indicate that AE ranks as a major procedure in the diagnosis and treatment of impotence.
The effect of intracavernous injection of papaverine (ICIP) has been investigated in 45 men: 6 normally potent volunteers, 10 psychogenic, and 29 organic impotent males. The first two groups obtained erections within 10 minutes, lasting from 1 to 4 hours, after injection of 80 mg of papaverine. Those belonging to the organic group experienced delayed, weaker and shorter erections, related to various degrees of arterial and/or venous and neurologic lesions. Haemodynamic and radiologic studies done concomitantly, showed a strong vasodilation in the penile arteries (even when pathologic) and a diminished outflow from the cavernous bodies. Subsequently, a pilot study was performed in a series of 63 patients suffering from various degrees of angiogenic impotence, in order to study the therapeutic effect of repeated intracavernous injections of papaverine completed by intracavernous infusion of heparinized saline. Erections improved significantly in 66% of the patients with a mean follow up of one year.
The injection of 80 mg of Papaverine into one of the corpora cavernosa of the penis produces an erectile response which is proportional to the local haemodynamic conditions. On the basis of this test, the investigation of penile rigidity coupled with Doppler velocity studies permit cases of impotence due to vascular disease to be differentiated from other abnormalities of erection. The intensity of the response is proportional to the quality of the local vascular reaction. The intense vaso-dilatation of the cavernous arteries leads the author to propose the use of this drug and this route of administration in the treatment of certain cases of poor erection due to arterial disease.
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