In vivo comparison of the coagulation capability of SonoSurg and Harmonic Ace on 4 mm and 5 mm arteries.

INTRODUCTION: Ultrasonic dissectors are useful to ligate arteries, but their effectiveness on larger arteries has not been thoroughly documented in vivo. The purpose of this study is to determine the bursting pressure of sealed arteries and the incidence of failure to adequately seal 4 mm and 5 mm arteries in a porcine model using two commercially available ultrasonic coagulators.
METHODS: The splenic, renal, superior mesenteric and carotid arteries of 60 kg swine were dissected and sealed alternating between SonoSurg (SS), 70% output (Olympus Surgical America) and Harmonic Ace (HA), level 3, (Ethicon Endosurgery). The burst pressures of each sealed segment was measured by subjecting them to infusion of water at 50 ml/hr until the seal burst. The mean burst pressure, incidence of burst pressure less than 360 mm Hg and incidence of not sealing were calculated and compared with the t and chi-square tests. Significance was assumed at p = 0.05.
RESULTS: Each instrument was used to divide 44 arteries measuring between 4 and 5 mm (4.7 +/- 0.48 mm vs. 4.7 +/- 0.44 mm, p = NS, SS vs. HA, respectively) in diameter. The burst pressure (900.2 +/- 574.9 mmHg vs. 896.6 +/- 481.0 mmHg, p = NS) was not different comparing SS with. HA. Four vessels (9.1%) failed to seal with each instrument and resulted in immediate hemorrhage. Including the vessel that failed to seal initially, five vessels (11.4%) ligated with SS and six (13.6%) ligated with HA had burst pressure less than 360 mm Hg. This incidence of inadequate sealing was not significantly different between the two instruments when compared with chi-square analysis.
CONCLUSION: SS and HA seal 4-5 mm arteries with similar burst pressures. There is no difference in the incidences of failure to initially seal the arteries or in bursting pressure <360 mmHg in 4-5 mm arteries in the porcine model.