Blood gas changes in the corpora cavernosa: metabolic and histomorphometric implications in the patient with erectile dysfunction

PURPOSE: We evaluated corpora cavernosa metabolism in flaccidity and in erection, analyzing some blood gas analytical parameters and comparing them by histomorphometric examination to find a direct relation between biochemical-metabolic parameters and histological data. MATERIALS AND METHODS: We selected 33 patients with erectile dysfunction and divided them into 2 groups, including 1-those with congenital penile deviation who were responders to prostaglandin E1, and 2-those with severe organic erectile dysfunction who were not responders to prostaglandin E1. We evaluated O(2) and CO(2) pressure, pH and O(2) saturation in blood samples. We then made a histomorphometric study of cavernous tissue. We obtained specimens by cavernous biopsies and calculated O(2) and CO(2) exchange, the Haldane effect and the respiratory quotient into the corpora cavernosa. All data were evaluated by statistical analysis. RESULTS: Mean O(2) arterial pressure and saturation +/- SD were lower in group 2 than in group 1 (74.85 +/- 8.78 versus 96.43 +/- 14.87 and 94.98 +/- 1.4 versus 97.35 +/- 0.83, respectively). Mean CO(2) arterial pressure was 35.59 +/- 4.78 group 1 versus 38.8 +/- 2.71 in group 2 with borderline statistical significance. The Haldane effect was superior in flaccidity than in erection because of the influence of arterial-venous O(2) difference and the respiratory quotient, which was also an inverse ratio. Cavernous histomorphometry showed that in group 1 smooth muscle was a mean of 38.8 +/- 8.94% of cavernous tissue versus 24.9% in group 2. CONCLUSIONS: Our study shows that starting with blood gas analytical data we can completely study the metabolism of the corpora cavernosa and its relationships to erectile dysfunction. Cavernous histomorphometry can suggest the presence of smooth muscle into cavernous tissue, whereas our mathematical elaboration allowed us to evaluate all data in a more complete manner.