Anatomy of the ureterovesical junction. The ureterovesical junction permits free antegrade urine flow from the upper urinary tract into the bladder and prevents retrograde urinary reflux from the bladder into the ureter and kidney. Passive compression of the distal sub-mucosal portion of the ureter against the detrusor muscle as a result of bladder filling impedes vesicoureteral reflux (VUR). An active mechanism preventing reflux also has been proposed in which contraction of longitudinally arranged distal ureteral muscle fibers occludes the ureteral lumen, impeding retrograde urine flow [1-3]. (From Politano [4]; with permission.)

0 0

Post a comment