One of the first systems developed in laparoscopic surgery was the ultrasonic-dissector.14--17 Therefore, the ultrasonically activated scalpel has been modified for use in laparoscopic surgery. It works with shears, usually oscillating at a frequency of 55.500 Hz and leads to a coagulation temperature between 50 and 100°C, while laser and other coagulation devices reach temperatures of 150 to 400° C. Ultrasonic-dissection separates tissue with a cavitational effect and achieves hemostasis by disrupting protein structure and forming a coagulum. It produces minimal local heat. A laparoscopic hook is used for cutting and tamponading tissues and vessels smaller than 2 mm. For larger vessels, up to 3 to 5 mm in diameter, ultrasonic coagulating shears are used. The laparoscopic tools are available as 5 and 10 mm instruments, and they offer the advantage of dividing tissue at the time of coagulation. The local heat to the surrounding region is not as much as in electrocautery, but it does exist.
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