electrosurgery

Electrosurgery uses high-frequency alternating current to produce tissue effects—such as cutting, coagulation, desiccation, or fulguration—during surgical procedures. It relies on current passing through the patient's tissues via an active electrode and a return electrode, creating localized heating that achieves the desired effect. This differs from electrocautery, where a heated instrument directly contacts tissue without current traversing the patient.

Mechanism: Tissue heating results from resistive heating as electrical energy is converted to heat within the tissue. In cutting modes, a continuous waveform rapidly vaporizes tissue to create an incision; in coagulation modes, an intermittent or pulsed waveform delivers energy in bursts, causing slower heating and vessel coagulation. Blended modes combine aspects of both aims.

Devices: Monopolar systems require a dispersive return pad placed away from the surgical site; current travels through the body to complete the circuit. Bipolar systems pass current between the two tips of a forceps and do not require a separate return pad. Use of insulation on instruments and proper grounding are essential to limit unintended current paths.

Safety: Potential risks include unintended thermal spread to adjacent tissue, burns at the electrode site, smoke plume, and interference with implanted devices. Proper pad contact, sterile technique, appropriate power settings, and adequate irrigation reduce risk. Pacemakers and other implants may be affected; bipolar devices reduce current through the patient and are often preferred in patients with implants.

Applications and history: Electrosurgery is used across general, laparoscopic, dermatologic, gynecologic, urologic, ENT, dental, and ophthalmic procedures. The technology was developed in the early 20th century by William T. Bovie, whose device popularized electrosurgery and led to widespread adoption.