Corporeal structure and vascular micro architecture with X-ray micro computerized tomography in normal and diabetic rabbits: Histopathological correlation

Purpose: The pathophysiology of diabetes mellitus induced erectile dysfunct ion is poorly understood. In patients with diffuse venous leakage structura l changes in the corpora cavernosa have correlated with failure of the veno -occlusive mechanism. Three-dimensional (D) micro computerized tomography ( CT) has proved to be an important imaging technique for the intact kidney, heart, liver and bone, We examined control and diabetic rabbit penises by 3 -D micro CT and quantified any structural changes. Materials and Methods: Male white New Zealand rabbits were treated with all oxan to induce diabetes or used as normal controls. Via aortic access at la parotomy the penile vascular tree was vasodilated with papaverine and perfu sed with radiopaque silicone rubber. X-ray micro CT was then performed at 2 1 mum. resolution and images were analyzed in 3-D using custom software. Results: Nine diabetic rabbits with blood glucose greater than 400 mg./dl. and 9 control animals were used for micro CT analysis. Significant decrease s (p <0.05) were observed in the. mean sinusoidal and vascular volume fract ion plus or minus standard error of mean of the corpus cavernosum in the di abetic (323.7 +/- 43.1 mm.(3) and 37.9 +/- 2.0%, respectively) and control (510.1 +/- 47.4 mm.(3) and 53.1 +/- 3.80%, respectively) groups. Also, the mean left and right cavernous artery luminal cross-sectional area in diabet ics (0.15 +/- 0.02 and 0.16 +/- 0.01 mm.(2), respectively) versus controls (0.3 +/- 0.01 and 0.2 +/- 0.01 mm.(2), respectively) was significantly decr eased (p <0.05). Furthermore, the mean left and right total cavernous arter y luminal volume in diabetics (0.4 +/- 0.07 and 0.4 +/- 0.09 mm.(3), respec tively) versus controls (1.0 +/- 0.13 and 0.9 +/- 0.11 mm.(3), respectively ) was significantly decreased (p <0.05). Conclusions: Diabetic rabbit penises showed a significant decrease in corpo real vascular volume as well as decreased cavernous artery diameter and lum inal volume compared to controls. This finding correlated well with the mea n decrease in trabecular smooth muscle in control and severely diabetic rab bits on histopathological studies (42.2% +/- 1.5% versus 35.8% +/- 1.5%). T his combination of potential arterial insufficiency as well as an increase in diffuse connective tissue mag contribute to the Overall pathophysiology of diabetic erectile dysfunction. These results suggest that 3-D x-ray micr o CT with molecular analysis may be a powerful tool for examining the patho physiology of diabetic erectile dysfunction.