Harmonic Scalpel

The Harmonic Scalpel system consists of : a current generator, and hand piece that houses an ultrasonic transducer, an instrument having an end effector (specific types include blade or shears) used to cut tissue, a foot pedal, and a hand switching adaptor.

The Harmonic Scalpel is the leading ultrasonic cutting and coagulation surgical device. It is a comprehensive system that has been used by thousands of surgeons worldwide in a broad range of both endoscopic and open surgical procedures.

How does it work?

Ultrasound is the basis for an efficient surgical instrument: the Harmonic Scalpel cuts and coagulates by using lower temperatures than those used by electro surgery or lasers. Harmonic Scalpel technology controls bleeding by coaptive coagulation at low temperatures randing from 50 degrees Celsius to 100 degrees Celsius: vessels are coapted (tamponaded) and sealed by a protein coagulum. Coagulation occurs by means of protein denaturation when the blade couples with protein, denaturing it to form a coagulum that seals small coapted vessels. When the effect is prolonged, secondary heat is produced that seals larger vessels. By contrast, electro surgery and lasers coagulate by burning (obliterative coagulation) at higher temperatures (150 Degrees C to 400 Degrees C). Blood and tissue are desiccated and oxidized (charred), forming eschar that covers and seals the bleeding area. Re-bleeding can occur when blades removed during electro surgery stick to tissue and disrupt the eschar.

Surgeons control the harmonic Scalpels coagulation rate and cutting speed by the time and force applied to the tissue by the end effector, and by the selected excursion level of the end-effector. At the tip of the end-effector, energy is delivered to tissue where it creates several effects within the tissue. Conversion of mechanical energy to heat from friction at the blade tissue interface occurs along with bulk heating due to tissue's viscoelastic nature. The Harmonic Scalpel uses ultrasonic technology, and energy that allows both cutting and coagulation at the point of impact. It is used for surgical procedures in which soft-tissue incisions will be made and in which bleeding control and minimal lateral thermal damage to tissue are desired. The instrument can be used as an adjunct to, or substitute for, electro surgery lasers and steel scalpels. When compared with electro surgery, fewer instrument exchanges are needed, less tissue charring and desiccation occur, and visibility in the surgical field is improved.

The Ultrasonic instrument has gained popularity in the operating room because of: the control given to the surgeon, reduced tissue damage, decreased operating times and more rapid healing.