Bursting tension of medium and large canine arteries sealed with ultrasonic energy or suture ligation

Objective-To compare bursting tension of arteries >= 3mm in diameter sealed with ultrasonic energy (UE) with arteries ligated with suture. Study Design-Experimental, nested factorial design. Sample Population-Vascular segments from canine cadavers. Methods-Arterial segments (12) were collected from each of 16 canine cadavers and equally divided into 2 groups based on vessel diameter (medium, 3.0-< 4.5mm; large, 4.5-< 6.0mm). Arterial specimens (3) from each group were sealed with either UE (Harmonic Scalpel (R), HS, power level 3) or suture ligation. The mean bursting pressure and tension were determined and compared. Results-Bursting tension was significantly higher (P <.0001) for sutured arteries than UE-occluded arteries, irrespective of size. Bursting tension was significantly higher (P=.0013) for medium than large UE-occluded arteries, whereas there was no difference associated with size for ligated arteries. UE energy failed to seal I medium artery and 7 large arteries. Compared with normal blood pressure, bursting pressures were 3.5 times greater for sutured arteries irrespective of size, 1.8 times greater for medium UE-occluded arteries, and approached normal blood pressure for large UE-occluded arteries. Conclusion-At the power level tested, UE should not be used to seal arteries > 4.5 mm in diameter. Suture provided an optimal seal for arteries < 6.0mm in diameter. Clinical Relevance-Use of UE to occlude arteries during laparoscopic surgery is advantageous because only I instrument is required to simultaneously cut and coagulate tissue, but care should be exercised where large arteries might be encountered. (c) Copyright 2005 by The American College of Veterinary Surgeons.