ABSTRACT
The pathophysiology of decreased bladder compliance from late radiation damage to the bladder wall in the patients includes cellular depletion and obliterative endarteritis leading to fibrosis and increased collagen content. The behavior of the bladder during filling depends on both mechanical and neuromuscular properties. Mechanical properties depend on tissue composition and structure of the bladder wall. High compliance of the bladder during initial filling is due primarily to its elastic and viscoelastic properties. Decreased compliance occurs due to several factors, including: fibrosis, bladder muscle hypertrophy, neurologic disease or injury affecting the lower urinary tract, and ischemia. Bladder muscle hypertrophy is often secondary to chronic bladder outlet obstruction. In normal bladders, delivery of blood flow is able to increase to match the large increase in surface area during filling. Increased intravesical pressure and intramural tension in low compliant bladders leads to a significant decrease in blood flow to the bladder wall.
