Biomechanical and histologic comparison of single-layer continuous Cushing and simple continuous appositional cystotomy closure by use of poliglecaprone 25 in rats with experimentally induced inflammation of the urinary bladder.
OBJECTIVE
To biomechanically and histologically compare single-layer continuous Cushing and simple continuous appositional cystotomy closure in rats with xylene-induced cystitis.


METHODS
40 female Sprague-Dawley rats.


METHODS
Rats were anesthetized, their urinary bladders catheterized and evacuated, and xylene instilled in each bladder for 5 minutes and then aspirated. Forty-eight hours later, ventral midline celiotomy and cystotomy (8 mm) were performed. Cystotomies were closed with 6-0 poliglecaprone 25 by use of a single-layer continuous Cushing or simple continuous appositional pattern (20 rats/group), and cystotomy times were recorded. Rats were allocated to healing durations (5 rats/group) of 0, 3, 7, and 14 days. Celiotomies were closed in a routine manner. After the allotted healing interval, another celiotomy was performed, the urethra cannulated, and ureters ligated. The cannula was secured to the urethra, and the bladder infused at 0.1 mL/min. Leak pressure volume, leak pressure, peak pressure volume, and peak pressure were recorded via a pressure transducer. Bladders were harvested and histologically assessed.


RESULTS
Cystotomy time, biomechanical testing values, and overall inflammation scores did not differ between closure methods for any healing duration. Both methods had significantly greater leak pressures, with the appositional method also having significantly greater peak pressures on day 7, compared to day 0. Biomechanical testing values decreased from day 7 to 14 as a result of juxtaincisional weakening of the bladder and xylene-induced changes in collagen.


CONCLUSIONS
Simple continuous appositional was equal biomechanically and histologically to continuous Cushing for all comparison variables. Poliglecaprone 25 was acceptable for cystotomy closure.
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA.
Blake Eason
BE
Hildreth
Gary W
GW
Ellison
John F
JF
Roberts
Christopher A
CA
Adin
Timothy J
TJ
Holloway
Linda L
LL
Archer
James M
JM
Van Gilder
D000818:Animals; D003559:Cystostomy / Q000379:methods*; D004146:Dioxanes; D004195:Disease Models, Animal; D004867:Equipment Design; D005260:Female; D007249:Inflammation / Q000601:surgery*; D011091:Polyesters; D051381:Rats; D017207:Rats, Sprague-Dawley; D013537:Sutures; D001745:Urinary Bladder Diseases / Q000601:surgery*
D004146:Dioxanes; D011091:Polyesters; C095495:glycolide E-caprolactone copolymer