Influence of barbed suture on leak pressures after double-layer inverting closure of cystotomy sites in sheep

To determine the influence of barbed suture on double-layer inverting closure of cystotomy sites in sheep.

Ex vivo study.

Urinary bladders harvested from ovine (n = 26) cadaveric specimens.

After collection and specimen preparation, a 3-cm-long incision was created on the ventral aspect of the urinary bladder. The cystotomy was repaired with barbed (n = 13) or nonbarbed analogous monofilament absorbable suture (n = 13) in a double-layer inverting suture pattern. Time required for closure in seconds was recorded for each test. Each bladder was connected to a pressure transducer to monitor intraluminal pressure during infusion with dyed Hartmann's solution until leakage occurred. Intraluminal pressure at time of initial leakage and leakage site were also recorded. Two-sample t tests were used to compare initial leakage pressure and closure time between the 2 types of suture (P = .05).

The mean ( ± SD) leakage pressure of ovine urinary bladder incisions did not differ between closures with barbed sutures (42.3 ± 21.7 mmHg) and nonbarbed closures (32.5 ± 14.4 mmHg, P = .187). Cystorrhaphies were performed faster with barbed suture (307 ± 50 seconds) than with nonbarbed suture (390 ± 62 seconds, P = .001).

The use of barbed suture did not affect mean leakage pressure of ovine urinary bladder incisions but decreased the time required to complete cystorrhaphies in this model.

This study provides evidence to support the use of knotless barbed suture for open ovine cystorrhaphies. Use of such suture for laparoscopic and laparoscopic-assisted procedures in sheep warrants caution until cyclic and in vivo testing is performed with appropriate laparoscopic instrumentation.