BACKGROUND: The sleeve gastrectomy is being performed increasingly as a primary procedure for the treatment of morbid obesity. A minimally invasive approach is currently applied to the procedure. The two major steps are dissection and stapling. For dissection, several tools have been developed. The goal of this study was to compare the efficiency and the ergonomics of two ultrasonic devices during the sleeve gastrectomy.MATERIALS AND METHODS: Thirty patients were randomised for the use of a cordless Sonicision™ (Covidien, Mansfield, MA) or a cord-containing HARMONIC ACE®+ (Ethicon Endo-Surgery Inc., Cincinnati, OH) during dissection. Both devices were assessed for objective and subjective measures.RESULTS: There was no significant difference in duration of the procedures. The assembly and installation time of the Sonicision™ were significantly shorter; however, the dismantle time was not. No difference in plume formation or dissection failures was found between the devices. Scrub nurses scored the Sonicision™ significantly clearer and easier in use and more reliable. The surgeons, however, did not find one of the devices easier in use, more reliable or precise, but they did report better manoeuvrability of the Sonicision™.CONCLUSION: In comparison to the wired HARMONIC ACE®+, during sleeve gastrectomy, the cordless Sonicision™ was considered easier to use, faster during assembling and installation, and more reliable with better manoeuvrability. Surgeons scored both devices equally effective. Both ultrasonic devices can be used easily and safely for a sleeve gastrectomy.@en