Hemodynamics of Penile Erection: III. Measurement of Deep Intracavernosal and Subtunical Blood Flow and Oxygen Tension (original) (raw)
J Urol, 1999
Purpose: The extent to which hemodynamic erectile responses predict penile buckling forces has not previously been analytically investigated. An engineering study was performed to compare hemodynamic data with penile buckling force values. Methods: Dynamic infusion pharmacocavernosometry studies in 21 impotent patients (age 43, range 24±62 y) were accomplished to obtain information during penile erection concerning hemodynamic values, penile buckling forces and their determinants: intracavernosal pressure, erectile tissue mechanical properties and penile geometry. Results: In the 21 patients, discrepancies existed in several patients who demonstrated normal hemodynamic values (low¯ow-to-maintain and high equilibrium intracavernosal pressures) but elevated cavernosal compliance values and diminished penile buckling forces. There was poor correlation between cavernosal compliance and equilibrium intracavernosal pressure (r 70.36); better correlation between compliance and expandability (r 70.72) and best correlation between dimensionless compliance and the dimensionless product of expandability with equilibrium pressure (r 70.88). These data implied that cavernosal compliance was dependent on multiple factors, not only equilibrium intracavernosal pressure. Conclusions: Hemodynamic indices which correlate with intracavernosal pressure alone do not predict penile buckling forces since the latter are dependent not only on intracavernosal pressure but also on penile geometry and erectile tissue properties. The most relevant tissue property in predicting adequate penile buckling forces is cavernosal expandability. A new impotence classi®cation system and diagnostic algorithm based on the determinants of penile rigidity and not exclusively on hemodynamic responses is proposed.
Cavernosal Arterial Anatomic Variations and Its Effect on Penile Hemodynamic Status
The Journal of Urology, 2002
Objecti6e: With continuous improvements in ultrasound technology, small vessels with remarkably slow blood flow that may not be assessed by color Doppler ultrasonography, can be evaluated using power Doppler ultrasonography. In the present study, penile arterial anatomic variations were determined with power Doppler ultrasonography and its impact on penile hemodynamic status. Methods: A total of 54 patients with erectile dysfunction were evaluated with power Doppler ultrasonography. The effects of vascular anatomic variations and the structure of the corpora cavernosa and tunica albuginea on vascular status were assessed on both sides. Results: A normal penile vascular system was observed in 35.2% and 25% of 54 patients (mean age: 46.6 911.5 years) at the radix and mid-shaft of the penis, respectively. Pure arterial component was observed in 40.7% (22/54) and 47.2% (17/36) of the patients at the base and mid-shaft of the penis, respectively. Penile arterial insufficiency was severe in 9.2 and 5.5% of the patients at the base and mid-shaft of the penis, respectively, whereas intrapenile truncus was found in six patients (5.5%), the ratio of single cavernosal artery, intrapenile and extrapenile bifurcations were 69.4, 7.4 and 12.0%, respectively. Twenty (18.5%) dorso-cavernosal perforators, 15 (13.9%) cavernoso-dorsal and 30 (27.8%) intercavernosal branches were found. Peak systolic blood flow velocity values were decreased in 12 of 36 patients (33.3%) distally, while increased blood flow was observed in 11 (30.5%). Conclusions: Hemodynamic parameters might be variable at either side of the penis and depend on intrapenile arterial anatomic variations. Parameters determined using power Doppler ultrasonography should be evaluated from the proximal to distal side of the penis to obtain reliable and standard results. However, variations of penile arterial anatomy and its effect on penile hemodynamic changes should not be overlooked especially in the patients who are candidates for penile reconstructive or vascular surgery.
International Journal of Impotence Research, 1997
Radionuclide tracer techniques are intimately associated with some of the early ground-breaking investigations in erectile dysfunction and have evolved along with the ®eld. At the present time, the various investigations can be grouped into four categories: labeled blood-pool; tracer washout; tracer washin and combined blood-poolatracer and tracer washout examinations. Blood pool studies are most useful in assessing the integrity of arterial in¯ow, but may also be used to generate indices of venous leak. A non-imaging version of the blood-pool test may represent a simple and cost-effective alternative. Washout of intracavernosal xenon during erection seems the most rigorous method of testing venous integrity. Washout using 99m Tc-labeled substances may emerge as a convenient alternative to the more technically dif®cult xenon examinations. Dual-isotope blood pool and washout examinations, though complicated, represent an ideal method of analyzing penile hemodynamics, with potential to contribute signi®cantly to the understanding of penile physiology. Development of improved pharmacologic stimuli and augmentation of testing protocols by intracavernosal pressure monitoring may further improve the utility of quantitative and physiologic nuclear medicine examinations in erectile dysfunction.
The Journal of Urology, 1993
The evaluation of vasculogenic impotence by color flow Doppler ultrasound after injection of intracavernous vasoactive agents allows for simultaneous visualization in real time of arterial and venous blood flow. Normal arterial blood flow parameters after prostaglandin E1 injection have yet to be standardized. Our study was initiated to evaluate blood flow parameters in a normal control population after prostaglandin E1 and visual stimulation. A total of 20 healthy male volunteers 45 to 60 years old with histories of normal sexual function was selected. All volunteers were given intracavernous injections of 10 JIg. prostaglandin E1 and received concurrent visual stimulation by means of an erotic video. All patients developed rigid erections with no complications. Using color flow Doppler ultrasound measurements were done before and after prostaglandin E1 injection of right and left superficial and deep cavernous artery diameters, peak blood flow velocities and blood flow volumes. Results (mean plus or minus standard error) showed a significant increase in diameters after prostaglandin E1 in the superficial (20% increase) and deep (70% increase) penile arteries. Blood flow volume increased 3-fold for the superficial penile arteries (from 7.3 ± 1.4 to 20 ± 3.5 cc per minute) and 4-fold for the deep cavernous arteries (from 3.8 ± 1 to 12.5 ± 1.8 cc per minute). Peak blood flow velocity increased 2-fold (from 22 ± 3 to 46 ± 7 cm. per second) for the superficial arteries and 3-fold (from 12.5 ± 2 to 37 ± 5 em. per second) for the deep cavernous arteries. These data suggest control values for normal erectile function in middle-aged men as a 70% increase in deep cavernous artery diameter, a systolic peak blood flow velocity greater than 30 cm. per second and more than 10 cc per minute of blood flow volume. With these standards the clinician may assess, design and follow treatment strategies for vasculogenic impotence.
Annals of the New York Academy of Sciences, 2007
A noninvasive diagnostic device was developed to assess the vascular origin and severity of penile dysfunction. It was designed and studied using both a mathematical model of penile hemodynamics and preliminary experiments on healthy young volunteers. The device is based on the application of an external pressure (or vacuum) perturbation to the penis following the induction of erection. The rate of volume change while the penis returns to its natural condition is measured using a noninvasive system that includes a volume measurement mechanism that has very low friction, thereby not affecting the measured system. The rate of volume change (net flow) is obtained and analyzed. Simulations using a mathematical model show that the device is capable of differentiating between arterial insufficiency and venous leak and indicate the severity of each. In preliminary measurements on young healthy volunteers, the feasibility of the measurement has been demonstrated. More studies are required to confirm the diagnostic value of the measurements.
A dual-radioisotope technique for the evaluation of penile blood flow during tumescence
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 1992
A technique is described for concomitant study of both arterial and venous penile blood flow during tumescence. Dual-isotope acquisition is started after labeling red cells in vivo with 99mTc. Xenon-133 in saline is then injected into the corpus cavernosum followed with vasoactive drugs to induce an erection. The resulting xenon and technetium time-activity curves are inputs for a one-compartment model. In 14 subjects, the average peak arterial flow rate (PAF) for normal males was calculated as 13.0 +/- 1.28 ml/min (avg +/- s.d.) compared to 16.1 +/- 5.14 and 5.02 +/- 1.78 ml/min for patients with venous leak (VL) or arterial insufficiency (AI), respectively. Peak venous flows (PVF) were 4.25 +/- 1.17, 12.1 +/- 3.75, and 3.78 +/- 1.00 ml/min for normal, VL and AL respectively. Al patients have significantly lower PAF than normal (p = 0.002) or VL patients (p = 0.018), and VL patients had significantly higher PVF than normal (p = 0.012) or Al (p = 0.018). The technique may be helpful...
A pilot study of penile hemodynamics in men with penile curvatures
International Journal of Impotence Research, 2017
Penile curvature (PC) is bothersome to the patient. PC is either congenital or acquired. In most of the circulatory system, blood flows in a laminar profile with minimal energy expenditure. When a fluid passes in a curved tube, the laminar profile is disturbed and changed into a turbulent flow. It increases the energy expenditure and reduces the flow. Turbulent flow may have a role in the development of an atherosclerotic plaque and in localizing its site. The aim of this research was to study penile hemodynamics before and after correction of PC. This prospective study included 20 participants, with PC more than 30°. For each participant, preoperative color duplex doppler ultrasonography (CDDU), correction of the curvature using 16 dot plication technique and postoperative CDDU were done. Furhtermore, arterial systolic velocity was estimated distal to the site of curvature/correction every 5 min for 25 min. The degree of curvature ranged from 30°to 90°with a mean of 55 ± 18.98. Comparative study between the preoperative and post-operative data proved a significantly higher postoperative peak systolic velocity distal to the site of correction, whereas CDDU data had insignificant differences. We concluded that correction of PC is associated with improvement of penile arterial blood flow distal to the site of correction.
Automated Bedside Measurement of Penile Blood Flow Using Pulse-Volume Plethysmography
Surgery Today, 2006
ful marker for assessing not only penile blood flow but also pelvic ischemia caused by internal iliac artery (IIA) occlusion. 4 Because Doppler PBP measurement is relatively easy and noninvasive, it is widely used in screening for vasculogenic impotence; however, the technique is time-consuming and requires much direct penile manipulation. Thus, a technique with less direct manipulation has been sought. We describe a new method for measuring both PBP and PBI using a device originally designed to measure ankle blood pressure (pulse wave velocity; PWV) and automatically calculate the ankle brachial blood pressure index (ABI). The purpose of this study was to assess the utility of this device and compare its results with those obtained by the Doppler ultrasound technique. Materials and Methods Forty men who underwent surgery in the Department of Surgery II at Hamamatsu University Hospital participated in this study. We conducted a private interview with each patient to obtain detailed information on sexual function, with emphasis on erectile capability. All measurements were done with the patients in the supine position. We measured the pressure in the bilateral dorsal penile arteries using Doppler ultrasonography (Model 811-B, Parks Medical Electronics, Aloha, OR, USA) by placing a 2.0-cm-wide cuff around the base of the penis. The higher of the two values was taken as the PBP, and the brachial systolic blood pressure was measured as the ratio of PBP divided by brachial systolic BP. Subsequently, a relatively new device,
Urology, 2002
Objectives. To assess the hemodynamics of the cavernous arteries (CAs) and helicine arteries (HAs) using power Doppler imaging (PDI) in patients with erectile dysfunction (ED). Methods. Forty-two patients with and without a definite vascular component of ED were examined by PDI. The hemodynamic variables of the CAs and HAs were measured after intracavernous injection of 20 g of prostaglandin E 1 . Results. The CAs and HAs were visualized clearly and could be evaluated by PDI after prostaglandin E 1 injection in all patients. The hemodynamic variables of both the CAs and HAs differed between the groups. In the nonvasculogenic group, all 18 patients had normal cavernous arterial flow and achieved a full rigid erection. The mean peak systolic velocity in the HA was 19.5 cm/s on the right and 19.1 cm/s on the left. In the vasculogenic group, 43% of the 14 patients with normal cavernous arterial flow achieved a full rigid erection and had hemodynamic variables comparable to those in the nonvasculogenic group, but 57% failed to achieve a full rigid erection and their mean peak systolic velocity in the HA (8.5 cm/s, P ϭ 0.0065 on the right; and 7.0 cm/s, P ϭ 0.0024 on the left) was lower than in the nonvasculogenic group. Ten patients had reduced cavernous arterial flow and a full rigid erection could not be achieved. The mean peak systolic velocity (7.8 cm/s, P ϭ 0.0009 on the right; and 6.5 cm/s, P ϭ 0.0004 on the left) was lower than in the nonvasculogenic group. Conclusions. PDI is useful for evaluating the hemodynamics of the penile arterial system in patients with ED. Our data suggest that abnormalities of the HA contribute to ED. UROLOGY 60: 480-484, 2002. © 2002,
Intracavernous pressure changes during reflexive penile erections in the rat
Physiology & Behavior, 1995
BERNABI~, J., O. RAMPIN, F. GIULIANO AND G. BENOIT. lntracavernous pressure changes during reflexive penile erections in the rat. PHYSIOL BEHAV 57(5) 837-841, 1995.-Reflexogenic penile erections have been previously described in the rat. However, exact involvement of the corpus cavernosum in reflex responses is indefinite. We report changes in intracavemous pressure (ICP) recorded in 10 awake rats by means of a telemetric device. The ICP changes and penile reflex responses (lengthening of the penile body, glans erection, cup, and flip) were recorded during ex copula tests. Each type of penile response was characterized by a specific ICP variation. Mean maximal ICP increase during lengthening of the penile body was 58.6 mmHg, during glans erection 67.3 mmHg, during cups 99.1 mmHg, and 215.2 mmHg during flips. ICP increases to 35.1 mmHg immediately preceding each cluster of penile responses. This study provides quantitative data on the involvement of the corpus cavernosum during reflexive ,erections. Tumescence of the corpus cavernosum was present during glans erection and suprasystolic ICP peaks occurred during flips. ICP measurements during reflexive erections should bring new insights into the analysis of their physiological mediation. Corpus cavernosum Telemetry Penile reflex Rat