Human penile hemodynamics by Xenon-133 clearance method in physiological erection.

We measured penile blood flow during physiological erection using the Xenon-133 clearance method in order to diagnose the exact cause of impotence. In 16 patients, in whom complete erection was obtained after visual sexual stimulation, the mean penile blood flow during erection was apparently higher than that in the flaccid state. On the contrary, in 6 patients whose reaction to visual stimulation was poor, penile blood flow did not change before and after stimulation. We considered that increased arterial flow was indispensable, but complete venous outlet obstruction was not necessary to produce a rigid erection. In addition, in the flaccid state the mean penile blood flow in the poor response group was apparently higher than that in the response group. This means that some patients who fail to obtain sufficient erection after visual sexual stimulation have increased venous outflow from the corpus cavernosum in the flaccid state. Based on these findings, the main cause of erectile dysfunction in such cases is probably attributed to disorders of the venous outlet system in the cavernous body.     

Functional evaluation of penile hemodynamics

A multidisciplinary study was performed on 200 consecutive patients with erectile dysfunction more than 1 year in duration, which included a standardized intracavernous injection of a vasoactive substance mixture (15 mg. per ml. papaverine plus 0.5 mg. per ml. phentolamine). The multidisciplinary findings correlated well with the intracavernous dose needed for full erection. The group without pathological hemodynamic findings (36 patients) needed an average of 0.67 ml. and the group with pathological inflow (107) needed an average of 1.07 ml. In the venous insufficiency group (57 patients) only 18 achieved full erections with an average of 2.1 ml. (39 achieved tumescence only to 3 ml.). The results show that standardized intracavernous injection of a vasoactive substance mixture is a useful method to evaluate penile hemodynamics. This pharmacological test appears to be effective in the differential diagnosis of nonvascular and vascular erectile dysfunction.     

Animal models for studying penile hemodynamics

Animal models for the study of erectile function monitoring the changes in intracavernous pressure (ICP) during penile erection was reviewed. The development of new models using small commercially-available experimental animals, rats and mice, in the last decade facilitated in vivo investigation of erectile physiology. The techniqueenabled to evaluate even subtle erectile responses by analyzing ICP and systemic blood pressure. Moreover, the method has been well improved and studies using conscious animal models without the influence of any drug or anesthesia are more appropriate in exploring the precise physiological and pharmacological mechanisms in erection. Also, more natural and physiological sexual arousal instead of electrical or pharmacological stimulation is desirable in most of the studies.This article reviewed the development of ICP studies in rats and mice.     

Human penile ossification

True human penile ossification is rare. We report such a case with roentgenologic evidence and histologic confirmation, and we offer some comments concerning etiology.     

The effect of vacuum devices on penile hemodynamics

External vacuum devices are being used increasingly for the management of erectile dysfunction. There is limited information regarding the effect of vacuum devices on penile blood flow and potential for ischemic penile injury. The penile xenon washout rate was measured before and after application of 2 vacuum systems in 15 subjects. Compared to flaccid state measurements the xenon washout rate did not change significantly with the Synergist Erection System but it was significantly reduced with the Osbon ErecAid System. However, the degree and duration of decrease in penile blood flow that may result in ischemic changes are unknown.     

A discrepancy of penile hemodynamics during visual sexual stimulation observed by near-infrared spectroscopy

Background

In this paper, we observed a discrepancy of penile hemodynamics dependent on location by using near infrared spectroscopy (NIRS) sensor, and showcase NIRS as a potentially suitable sensor in supplementing the diagnosis and treatment of erectile dysfunction.

Methods

To observe the effect that location has on penile hemodynamics, the NIRS sensor was placed on the top and the side of genital organ, and oxy- (HbO), deoxy-(RHb), and total (HbT) hemoglobin concentration changes were acquired. Our results from 6 healthy subjects show that hemodynamic changes vary depending on where the probe was placed. To observe a statistical difference between the signals, a Wilcoxon signed-rank test was performed.

Results

The result shows a significant difference (p < 0.05) between concentration changes of RHb and HbT depending on the probes’ location. Moreover, the sensor placed on the top of the organ shows a rise of HbO and HbT concentration while RHb concentration decreased. However, hemodynamics from the side of the organ showed that RHb concentration increased along with HbO.

Conclusions

The outcomes demonstrates an ability of NIRS to be sensitive enough to detect the different hemodynamic changes in various locations of a healthy male genital organ during visual sexual stimulation. The results also show the importance of sensor location on the genital organ for the resulting hemodynamic changes. We can foresee our results as a way for clinicians to obtain more accurate hemodynamic measurements from the penis, and also show the likelihood for NIRS enhanced diagnosis tool of male erectile dysfunction over the current standards.     

Human bone microstructure studied by collagenase etching

Bone samples from the iliac crest of patients with no signs of bone disorder were treated with collagenase to remove the collagen component and so allow detailed observation of the mineral hydroxyapatite. Both polished and unpolished surfaces were studied in the scanning electron microscope and they showed that the mineral component of bone is composed of small rounded units about 10 nm across which are fused together to form larger spheroidal units roughly 100 nm in diameter. In the unpolished surfaces these 100 nm units are seen to aggregate to form columns approximately parallel to their neighbours and with numerous interconnections forming a continuous mineral phase. The polished sections also show the hydroxyapatite as a continuous phase of contiguous spheroids and the holes from which the collagen fibres were removed are clearly revealed. Lamellations in the surface are interpreted as resulting from adjacent layers of collagen fibres having orientations approximately perpendicular to each other.     

Laser oximetry: A novel noninvasive method to determine changes in penile hemodynamics in an anesthetized rabbit model

This study was designed to determine the utility and validity of laser oximetry in measuring changes in penile hemodynamics. Anesthetized male New Zealand White Rabbits were divided into 2 groups, and penile hemodynamics were assessed by either laser oximetry (oxyhemoglobin, deoxyhemoglobin concentration, and oxygen saturation) or intracavernosal pressure (ICP) monitoring during penile erection induced by pelvic nerve stimulation (PNS) or intracavernosal administration of phentolamine, nitroprusside, papaverine, or sildenafil. PNS caused significant frequency-dependent increases in penile ICP. PNS also caused significant increases in penile tissue oxyhemoglobin concentrations and tissue oxygen saturation in a frequency-dependent manner. The changes in oxyhemoglobin concentrations and oxygen saturation correlated with frequency-dependent increases in ICP. Intracavernosal vasoactive drug administration produced significant increases in ICP, tissue oxyhemoglobin concentration, oxygen saturation, and duration of response as a function of increasing drug concentration. Laser oximetry permits reproducible and valid assessment of changes in penile hemodynamics comparable to conventional ICP measurements. Thus, we consider laser oximetry a reliable technique in evaluating penile hemodynamics. Its sensitivity in detecting small changes in oxyhemoglobin concentration and its noninvasive nature make it advantageous over invasive methods such as ICP monitoring and laser Doppler flowmetry.     

血管性阳痿阴茎血流动力学研究及微循环检测

目的：研究血管性阳痿病人阴茎头微循环及其血流动力学特点,并对二者相关性进行比较。　方法：分别检测１７ 例血管性阳痿病人和１１ 名健康志愿者的阴茎头微循环,同时用超声多普勒研究其血流动力学指标,并分析二者间的相关关系。　结果：血管性阳痿病人与健康志愿者阴茎头微血管密度为（２７．１±５．２）条／ｍ ｍ ２ ｖｓ （４７．８±６．２）条／ｍ ｍ ２ （ Ｐ＜ ０．０１）,异常微血管百分率为（３２．１±３．４）％ ｖｓ （１２．８±１．３）％ （ Ｐ＜ ０．０１）及阴茎 臂指数（ Ｐ Ｂ Ｉ）值与对照组相比差异显著;阴茎血流动力学指标中 Ｐ Ｂ Ｉ值与微循环检测的两项指标均显著相关;阴茎血流动力学指标中阴茎各动脉的血流速度与微循环指标相关不明显。　结论：血管性阳痿病人的阴茎头微循环有器质性改变,这种改变与阴茎血流动力学之间相关不明显,阴茎血流动力学指标的检测易受各种因素的干扰。     

益肾壮阳膏对勃起功能障碍阴茎血流动力学的影响

目的:观察益肾壮阳膏对ED患者阴茎海绵体动脉血流动力学参数的影响,探讨其作用机制。方法:选取门诊92例ED患者,随机分为观察组(n=60)和对照组(n=32),分别予益肾壮阳膏和安慰剂治疗,疗程4周,比较治疗前后IIEF-5评分、阴茎勃起硬度评分(EHS)及阴茎海绵体动脉血流动力学参数。结果:治疗后观察组IIEF-5、EHS较治疗前显著升高[(19.18±3.56)分vs(12.63±3.78)分,(3.58±0.50)分vs(3.21±0.62)分,P均0.01],且显著高于对照组治疗后评分[(19.18±3.56)分vs(13.72±2.85)分,(3.58±0.50)分vs(3.28±0.58)分,P均0.01)];但两组间及组内治疗前后阴茎海绵体动脉收缩期峰值流速、舒张末期流速、阻力指数变化均无统计学意义(P均0.05)。观察组治疗有效率为73.33%,优于对照组的21.88%(Z=-4.665,P0.01)。结论:益肾壮阳膏对ED患者有较好的改善作用,可以提高阴茎勃起硬度及改善IIEF-5评分。但阴茎血流动力学无明显改变,其作用机制需进一步研究。     

Erectile mechanism studied using penile vascular casts in the dog

The possible mechanism of penile erection was discussed based on the findings obtained by the scanning electron microscope observations of the penile vascular casts in the dog. Polsters protruding into the lumen of the distal helicine arteries regulate blood flow into the cavernous spaces. The drainage veins from the corpus cavernosum penis arose on the dorsal surface and crept on the corpus until changing direction perpendicularly. This suggested that these veins were efficiently compressed between the tunica albuginea and the corpus cavernosum penis during erection. For a high pressure to be maintained in the cavernous spaces during erection, a closed system separated from the systemic circulation must be required.     

Hypothesis of human penile anatomy, erection hemodynamics and their clinical applications

Aim： To summarize recent advances in human penile anatomy, hemodynamics and their clinical applications. Methods： Using dissecting, light, scanning and transmission electron microscopy the fibroskeleton structure, penile venous vasculature, the relationship of the architecture between the skeletal and smooth muscles, and erection hemodynamics were studied on human cadaveric penises and clinical patients over a period of 10 years. Results： The tunica albuginea of the corpora cavernosa is a bi-layered structure with inner circular and outer longitudinal collagen bundles. Although there is no bone in the human glans, a strong equivalent distal ligament acts as a trunk of the glans penis. A guaranteed method of local anesthesia for penile surgeries and a tunical surgery was developed accordingly. On the venous vasculature it is elucidated that a deep dorsal vein, a couple of cavernosal veins and two pairs of para-arterial veins are located between the Buck＇s fascia and the tunica albuginea. Furthermore, a hemodynamic study suggests that a fully rigid erection may depend upon the drainage veins as well, rather than just the intracavemosal smooth muscle. It is believed that penile venous surgery deserves another look, and that it may be meaningful if thoroughly and carefully performed. Accordingly, a penile venous surgery was developed. Conclusion： Using this new insight into penile anatomy and physiology, exact penile curvature correction, refined penile implants and promising penile venous surgery, as well as a venous patch, for treating Peyronie＇s deformity might be performed under pure local anesthesia on an outpatient basis. （Asian J Androl 2006 Mar; 8： 225-234）     

Effects of extra—corporeal shock waves on penile hemodynamics and histopathology in rats

Aim: To study the effect of extra-corporeal shock wave (ESW) on the penile hemodynamics and histopathology in rats. Methods: Adult male Sprague-Dawley rats were divided at random into 3 groups. ESW application was performed with a Siemens Lithostar with the rats under anesthesia lying prone on the balloon probe. Rats in Group Ⅰ received a total of 1000 shocks at 18 kV and immediately underwent hemodynamic evaluation performed by direct electrostimulation of the cavernous nerve and measurement of intracavernous pressure (ICP). Rats in Group Ⅱ received 3 times 1000 shocks at 18 kV at weekly intervals and hemodynamic evaluation was performed 1 month after the last ESW application. Group Ⅲ served as the control. Histopathological examinations of penile tissues were done on Masson's trichrome and hematoxylin and eosin stained sections. Results: Penile hemodynamic evaluation showed a trend toward a diminished mean maximal ICP, duration of erection, ICP during the plateau phase and maximal ICP/blood pressur     

Human penile ossification. A case report

A 53-year-old man had suffered from plastic induration of the penis (Peyronie's disease) for 4 years. The firm plaque surgically removed from the proximal dorsal part of the penis showed bone formation at histologic examination.