Effects of vesical and perfusion pressure on perfusate flow, and flow on vesical pressure, in the isolated perfused working pig bladder reveal a potential mechanism for the regulation of detrusor compliance

Abstract

Perfusate flow is dependent on bladder perfusion pressure, and not necessarily reciprocally dependent on vesical pressure. Vesical pressure is highly sensitive to the level of perfusate flow, which supports the hypothesis that vesical pressure is dependent on the level of detrusor smooth muscle contractile activity (tone), and that compliance is dependent on bladder perfusion.

Potential vascular mechanisms in an ex vivo functional pig bladder model

“…Although porcine models have been developed to evaluate whole bladder function ex vivo, few have expressly focused on evaluation of bladder perfusion. In a previous study, we prepared an isolated perfused working pig bladder model which confirmed that decreased bladder perfusion occurs with increasing vesical pressure during the filling phase . This study demonstrated that normal bladder filling may be associated with transient periods of relative ischemia.…”

“…At the time of use, additional dissection was performed to remove excess tissue, and each bladder was weighed. Cannulation of the right and left vesical arteries as well as one ureter (used for intravesical pressure monitoring) was performed and a urethral catheter was placed as previously described . A 22‐gauge Jelco IV catheter (Smiths Medical, Minneapolis, MN) was carefully inserted into the anterior detrusor muscle with care taken not to violate the bladder lumen.…”

An external compress‐release protocol induces dynamic elasticity in the porcine bladder: A novel technique for the treatment of overactive bladder?

“…Bladders from adult male (castrated) and female pigs were obtained from local abattoirs immediately after slaughter. As previously described, the dissection included removal of the bladder, urethra, ureters, and vascular tree including a section of the aorta, iliac arteries, branching vesical arteries, and corresponding venous system . The aorta was cannulated and cold‐perfused with heparinized Krebs‐Henseleit (KH) buffer .…”

“…As previously described, the dissection included removal of the bladder, urethra, ureters, and vascular tree including a section of the aorta, iliac arteries, branching vesical arteries, and corresponding venous system . The aorta was cannulated and cold‐perfused with heparinized Krebs‐Henseleit (KH) buffer . Tissues were stored in 3‐(N‐morpholino) propanesulfonic acid (MOPS) based buffer and transported to the lab for use within approximately 3 hours or stored for use within 48 hours .…”

“…The present study utilizes an innovative external bladder compression protocol to test the hypothesis that dynamic elasticity can be manipulated in a noninvasive manner. The aim of this study was to determine if strain softening produced by repeated noninvasive isovolumetric compression‐release cycles is equivalent to strain softening produced by filling and passive emptying in an isolated perfused pig bladder model . As a result, this study may represent an essential step toward the development of a novel, noninvasive technique to identify dynamic elasticity and to reduce intravesical pressure and possibly urinary urgency.…”