Ex vivo comparison of single-layer and double-layer laparoscopic closure of equine bladders with 2 types of barbed sutures.

Objective: To compare laparoscopic single-layer versus double-layer closure of experimental, full-thickness incisions in adult equine urinary bladders using unidirectional and bidirectional barbed suture.

Study Design: Experimental, ex vivo, surgical study.

Sample Population: Thirty adult equine cadaver urinary bladders.

Methods: Bladders were randomly divided into 5 groups (n = 6): intact controls, bladders sutured with unidirectional or bidirectional barbed suture in a single-layer closure, and bladders sutured with unidirectional or bidirectional barbed suture in a double-layer closure. A 5-cm apical incision was created in each bladder assigned to a suture group, prior to closure in a laparoscopic trainer. After suturing, bursting pressures (BPs) were determined by filling the bladders with saline to failure. Continuous variables were compared among groups using generalized linear modeling with post hoc testing between groups, and categorical variables were compared using Fisher's exact test. Significance was set at P < .05.

Results: No difference in BP was detected between treatment groups, all failing at pressures lower than those of intact bladders. The 95% confidence interval for BPs exceeded a physiologically relevant threshold of 30 mm Hg after single-layer or double-layer closure. Irrespective of treatment group, surgical time decreased with experience, and the rate of reduction was greater for the single-layer than the double-layer closures.

Conclusion: In this ex vivo study, both closure techniques and both suture types appeared to be acceptable for laparoscopic closure of the urinary bladder in adult horses.