Clinical Application of Ultrasound-guided Electrode Placement and Detection of Nerve Action Potential

Abstract

Objective: To explore a minimally invasive detection method to evaluate the early-stage quality of nerve suture by combining ultrasound and nerve electrophysiological examinations. Methods: Ten patients with median and/or ulnar nerve injuries undergoing nerve suture surgery were recruited. Ultrasound examination found that the nerve injury was sutured and continual nerve suture was observed. Electrophysiological examination detected no nerve function. Stimulating electrode and recording electrode were located beside the nerve guided by ultrasound after nerve suture. Nerve action potential (NAP) was detected with these electrodes under ultrasound. Surgical exploration was conducted and NAP detection was performed during surgery. The amplitude, latency and wave shape of NAP between ultrasound-guided and intraoperative detection were statistically compared. Results: Among 10 patients, 3 patients were diagnosed with median nerve injury, 2 cases of ulnar nerve injury and 5 cases of median nerve complicated with ulnar nerve injuries. NAP could not be detected under ultrasound or during surgery in 3 median nerves from 3 cases and 2 ulnar nerves from 2 cases. NAP was detected in 10 nerves from the remaining 5 cases. The detection results of NAP under ultrasound and during surgical exploration showed consistent performance in testing the conduction of nerve suture. Wilcoxon's signed-rank test indicated no significant difference in the amplitude and latency detected under ultrasound and during surgical exploration. The negative-phase waves were equally detected under ultrasound and during surgical exploration. Conclusion: Ultrasound-guided detection of NAP can substitute surgery and serve as a minimally invasive approach to evaluate the function of nerve suture site.