Canine Bladder Blood Flow and Oxygenation: Changes Induced by Filling, Contraction and Outlet Obstruction

PURPOSE: To study changes in bladder blood flow and oxygenation associated filling, contraction and outlet obstruction. MATERIALS AND METHODS: Intravesical pressure, bladder flow, bladder wall oxygen tension, iliac artery blood flow and systemic blood pressure were measured simultaneously in anesthetized dogs (N = 18). RESULTS: In the empty bladder, blood flow and oxygen tension in the bladder were greater than at the dome with and without outlet obstruction. Bladder filling caused a significant decrease in bladder wall blood flow and oxygen tension with or without outlet obstruction. Spontaneous bladder contractions resulted in a marked decrease in bladder wall perfusion in the obstructed bladder but not in the unobstructed bladder. Pelvic nerve stimulation produced strong bladder contractions associated with significant drop in bladder wall perfusion and bladder oxygenation in both the open and closed bladder neck models. Little change was noted after stimulation of the hypogastric nerve. CONCLUSIONS: Bladder distention and contraction, especially against a closed bladder neck, induce significant ischemia and hypoxia of the bladder wall. These findings may be important in the pathophysiology of a variety of common clinical problems.