Application of computerised penile arterial waveform analysis in the diagnosis of arteriogenic impotence. An initial study in potent and impotent men

Validation of a continuous penile blood-flow measurement by pulse-volume-plethysmography

Today, in the assessment of cavernous artery blood-flow, the most commonly used technique is Doppler ultrasound velocimetry (continuous, pulsed, color-coded or power), which is often considered as the gold standard. Plethysmographic techniques and radioactive tracers have been widely used for the assessment of global penis flow variations but are not adequate for continuous blood-flow measurement. A new pulse-volume plethysmographic (PVP) device using a water-filled penile cuff was employed to assess continuous blood-flow measurement in the penis. Simultaneously Doppler velocity was recorded and served as a gold standard. A penile water-cuff is connected through a pressure tube to a three-way tap. The pulse-volume changes in the penile water-cuff are measured by means of a latex membrane placed over one of the three-way taps. The displacements of the latex are recorded by a photoplethysmograph. The third tap is connected to a 5 l perfusion bag placed 30 cm above the penis so as to maintain constant pressure in the whole device whatever the penis volume. Twenty-four volunteers were tested. The Doppler velocity signal and pulse volume of cavernous arteries were measured simultaneously after PGE1 intra-cavernous injection. Blood-flow variations were induced by increasing penis artery compression with a second penile water-cuff used as a tourniquet fitted onto the penis root, and the pressure of which could be modified by a water-filled syringe. The amplitude of the plethysmographic pulse-volume signal and the area under the Doppler velocity signal were correlated. The inter-patient (n=24) correlation ranged from 0.455 to 0.904, with a mean correlation of 0.704 and P<0.0001. PVP measurement by a water-filled cuff was validated by ultrasound velocimetry. This new continuous, non-invasive and easy-to-use technique enables physiological and physiopathological flow-measurement during sleep, under visual sexual stimulation (VSS), or following artificial erection. Simultaneous recording of penile blood-flow by PVP and intra-cavernous pressure (ICP) measured by a non-invasive device will provide fundamental inflow and outflow information in both physiological and pathophysiological conditions, and further enable venous leakage to be assessed by a mathematical model.

Non-invasive assessment of arteriogenic impotence: a comparative study

This study was undertaken to determine the relative accuracy of computerised Doppler waveform analysis and colour coded duplex ultrasonography in the diagnosis of arteriogenic impotence. Twenty men with ostensibly normal penile haemodynamics were compared with 50 men whose impotence was considered due to compromised penile haemodynamics. In each patient the penile arterial inflow was assessed by both methods of investigation, which were performed at an interval of 2 weeks. The results demonstrated both techniques to be sensitive in detecting penile artery insufficiency but colour coded duplex ultrasonography was significantly more accurate.

Pharmacocavernometry: a modified papaverine test

The papaverine test has become established in the investigation of impotence. Although a full response to papaverine excludes a significant vascular lesion, failure to respond may be due to either arterial deficiency or venous leakage. Pharmacocavernometry, which combines the papaverine test and an artificial erection test, was performed in 126 patients. Intracorporeal pressure was monitored following the intracorporeal injection of 80 mg papaverine; 10 min later, saline was infused to determine the presence of a venous leak. Five different responses were observed. Patients with a Type 1 or 2 response were psychogenic or neurogenic. Patients with a Type 3 response were arteriogenic and patients with a Type 4 or 5 response had significant venous leakage. The modified papaverine test permits more information to be gained concerning the aetiology of the impotence.

Saline-induced artificial erection without papaverine: a potential source of error in diagnosing cavernosal venous leakage

The diagnosis of venous leakage as a cause of impotence, based on failure to induce an artificial erection by means of rapid saline infusion alone, may be invalid. Our recent experience with 2 men whose impotence was subsequently found to be psychogenic in nature suggests that saline erection cavernosometry should routinely incorporate the intracavernosal administration of papaverine, in order to avoid a falsely positive diagnosis of venous leakage.

Neurophysiological investigation of diabetic impotence. Are sacral response studies of value?

The role of electrophysiologically elicited sacral responses in the detection of the neurological component of diabetic impotence has been evaluated in a detailed study using properly defined diagnostic criteria. The results prove that these tests are not reliable indicators of neuropathy and their relevance in the routine investigation of diabetic impotence is of questionable value.