How to prevent lateral thermal damage to tissue using the harmonic scalpel: experimental study on pig small intestine and abdominal wall.

INTRODUCTION: When using a harmonic scalpel, the lower amount of energy that is transduced to the tissue reduces the chance of lateral thermal damage.
METHODS: Pigs (weight: 40 kg) were used as the experimental model. After anesthesia, tissue was coagulated using different application regimens for each group. The width of tissue necrosis was measured from the point of incision by the harmonic scalpel.
RESULTS: The pig abdominal tissues suffered mean thermal damage of 0.0825 (output power 3) and 0.2969 mm (output power 5) when used for 5 s; at 10 s these values were 0.3850 and 0.4793 mm, respectively. In a third experimental condition, with 10 s of application broken down into 2 parts of 5 s with a 5-second pause in-between, these values were 0.1876 and 0.2013 mm, respectively. The small intestine tissues suffered mean thermal damage of 0.1302 (output power 3) and 0.1771 mm (output power 5) at a duration of 5 s. After 10 s of application, these values changed to 0.2655 (output power 3) and 0.2983 mm (output power 5). In the third condition (activity for 5 s, pause for 5 s, activity for 5 s), they were 0.2011 and 0.2258 mm, respectively.
CONCLUSION: Coagulation necrosis is bigger if the usage is continuous rather than if it is disconnected/reconnected. Copyright 2009 S. Karger AG, Basel.