Three-way bipolar forceps: a novel bipolar coagulator system for nerve stimulation and detection of nerve potentials

Preoperative characterization of brain anatomy by magnetic resonance imaging and intraoperative functional characterization of the nervous system is essential in patients undergoing radical resection of brain tumors. A novel integrated system was developed combining conventional bipolar forceps with an electric stimulator and an oscilloscope. The system consists of a mechanical switching circuit allowing a wide range of electric characteristics and was designed to perform intraoperative electrophysiological studies, including functional mapping and measurements of motor evoked potentials (MEPs) and somatosensory evoked potentials (SEPs). This system achieved a significant reduction in exchange time (from 3.63+/-1.00 sec to 1.12+/-0.42 sec) between coagulation and stimulation, and reproducible measurement of MEPs from porcine limbs by cortical stimulation using the bipolar forceps. Functional mapping under awake craniotomy was carried out by cortical stimulation in patients with glioblastoma, and median nerve SEPs with high signal-to-noise ratio were elicited from the bipolar forceps on the sensory cortex of patients under general anesthesia. This integrated system is technically easy to operate and allows functional monitoring of an area that would otherwise be difficult to access using conventional methods. This three-way bipolar forceps system may reduce postoperative complications in patients undergoing neurosurgical procedures.