Objective: Organic female sexual dysfunction may be related in part to vasculogenic impairment of the hypogastric-vaginal/clitoral arterial bed. The aim was to develop an animal model of vaginal engorgement insuf®ciency and clitoral erectile insuf®ciency.Methods: Pelvic nerve stimulated vaginal engorgement and clitoral erection were achieved in control (normal diet, n 8) and atherosclerotic (balloon injury of aorto-iliac arteries and 0.5% cholesterol diet, n 7) New Zealand White female rabbits. After 16 weeks, novel hemodynamic variables including vaginal wall and clitoral blood¯ow, vaginal wall and clitoral intracavernosal pressure, vaginal length, vaginal luminal pressure, blood levels of cholesterol and triglycerides, aorto-iliac angiography and vaginal wall and clitoral erectile tissue histology were recorded in the two groups.Results: Concerning pelvic nerve stimulated vaginal hemodynamic changes, there was signi®cantly less increase in blood¯ow (ml/min/100 gm tissue), wall pressure (mmHg) and length changes (mm) in atherosclerotic (9.3 AE 3.7, 4.8 AE 3.8, 67.3 AE 8.3) compared to control (13.9 AE 4.5, 5.5 AE 2.6, 74.1 AE 10.0) animals respectively. Histologic examination of clitoral erectile tissue demonstrated cavernosal artery atherosclerotic changes and diffuse vaginal and clitoral ®brosis. Aorto-iliac angiography in atherosclerotic animals revealed diffuse moderate to severe atherosclerotic occlusion.Conclusions: Vaginal engorgement and clitoral erection depend on increased blood in¯ow. Atherosclerosis is associated with vaginal engorgement insuf®ciency and clitoral erectile insuf®ciency.

Aim: An improved understanding of the relationship between radial and axial rigdity values would enable better appreciation of the clinical usefulness of RigiScan TM , the most widely utilized determination of erectile rigidity testing. Previous studies have shown that axial rigidity (measured by buckling forces) correlated well with radial rigidity (measured by RigiScan TM ) for radial rigidity values below 60%. For radial rigidity exceeding 60%, there was poor correlation. Heretofore, there has been no physiologic explanation of this phenomenon. Methods: During dynamic pharmacocavernosometry in 36 impotent patients, we investigated the relationship between axial buckling forces and RigiScan TM radial rigidity and, for the ®rst time, how they both vary with pressure, (which we varied over over a wide functional range). In addition, we recorded multiple penile length and diameter values enabling us to relate, also for the ®rst time, axial and radial rigidity to individual mechanical erectile tissue and penile geometric properties. Results: Marked differences were found in the manner RigiScan TM radial rigidity units and axial buckling force magnitudes increased with increases in intracavernosal pressure values in each individual. The former asymptotically approached a maximum ®nite value while the latter increased continuously towards in®nity. Based on data in this study, RigiScan TM radial rigidity values greater than 55% may be considered a necessary criteria for vaginal intromission capability in all partners but it is not a suf®cient one. Conclusions: Axial and radial rigidity share a common dependency upon intracavernosal pressure, however, they are also dependent upon other unique physical determinants. For axial rigidity, additional dependent variables include cavernosal erectile tissue properties and penile geometry, while for radial rigidity, this may include tunical surface wall tension properties. Clinical devices which assess functional penile rigidity should utilize axial and not radial rigidity testing.

In our previous studies we found that aging-associated ®brosis of clitoral cavernosal tissue correlated with the prevalence of cardiovascular disease in elderly women. The aim of this study was to determine speci®cally, arterial insuf®ciency-related structural changes of clitoral cavernosal tissue in a rabbit model. New Zealand white female rabbits were divided into clitoral cavernosal ischemia (CCI, n 5) and control (n 5) groups. The CCI group underwent balloon endothelial injury of the iliac arteries and received 0.5% cholesterol diet. The control group received a regular diet. After 16 weeks, arteriography was performed then the animals were sacri®ced. The iliac arteries and the entire clitoris were removed. Cross-sections of the iliac arteries and clitoris were processed for histologic eva1uation The percentage of smooth muscle and connective tissue in trichrome stained sections of clitoral cavernosal tissue was determined by computer-assisted histomorphometry. Arteriography revealed diffused occlusive disease in the common iliac, internal iliac and pudendal arteries in the CCI group. Histology showed that arterial occlusive disease spreads from the site of balloon injury to the smaller branches involving the clitoral cavernosal arteries. Diffuse ®brosis was observed in the clitoral cross-sections of the CCI group. The percentage of clitoral cavernosal smooth muscle (mean AE standard error) in the CCI group (53% AE 0.9%) was signi®cantly decreased compared with the control group (62% AE 0.8%) (P 0.0001). Chronic clitoral cavernosal ischemia causes signi®cant ®brosis and loss of smooth muscle in the clitoral cavernosal tissue. These ®ndings suggest that chronic clitoral cavernosal arterial insuf®ciency may play a role in the pathophysiology of female sexual arousal disorders.