Value and pitfalls of neurophysiological monitoring in thoracic and thoracoabdominal aortic replacement and endovascular repair.

ABSTRACT

BACKGROUND: The aim of our study was to analyze the neurophysiological monitoring method with regard to its potential problems during thoracic and thoracoabdominal aortic open or endovascular repair. Furthermore, preventive strategies to the main pitfalls with this method were developed. METHODS: Between 11/2000 and 05/2007 in 97 cases open surgery or endovascular stentgraft-implantation was performed on the thoracic or thoracoabdominal aorta. Intraoperatively, neurophysiologic motor- and somatosensory-evoked potentials were monitored. RESULTS: Our cases were divided into four groups event-free patients with normal potentials (A, 63 cases), with correlation of modified evoked potentials and neurological outcome (B, 14 cases), false-positive or false-negative results (C, 4 cases), and medication interaction or technical issues (D, 16 cases). We observed a sensitivity of 93 % and a specificity of 96 % for the neurophysiological monitoring. CONCLUSIONS: Monitoring spinal cord function during surgical and endovascular interventions on the thoracic and thoracoabdominal aorta is necessary. It can be made more effective by precisely analyzing the interference factors of the neurophysiological monitoring method itself. Successful strategies of immediate troubleshooting could be identified.