Constantin Gomes1, Mathieu Kuchenbuch1, Grégory Lucas2, Soizic Argaud3, Philippe Violas2, Paul Sauleau4,5. 1. Department of Neurophysiology, Rennes University Hospital, 35033, Rennes, France. 2. Department of Pediatric Orthopedic Surgery, Rennes University Hospital, 35033, Rennes, France. 3. "Behavior and Basal Ganglia" Research Unit (EA 4712), EA 4712 "Comportement et Noyaux Gris Centraux", Faculté de Médecine, Université de Rennes 1, Avenue Léon Bernard, 35043, Rennes, France. 4. Department of Neurophysiology, Rennes University Hospital, 35033, Rennes, France. paul.sauleau@univ-rennes1.fr. 5. "Behavior and Basal Ganglia" Research Unit (EA 4712), EA 4712 "Comportement et Noyaux Gris Centraux", Faculté de Médecine, Université de Rennes 1, Avenue Léon Bernard, 35043, Rennes, France. paul.sauleau@univ-rennes1.fr.
Abstract
PURPOSE: To assess the validity and utility of monopolar stimulation (between a peridural needle and a large adhesive anode placed in the sternal area) for intraoperative monitoring in scoliosis surgery. METHODS: This procedure was assessed during 41 operations involving either arthrodesis with posterior instrumentation or a Vertical Expandable Prosthetic Titanium Rib (VEPTR). Responses evoked by monopolar stimulation were compared with those evoked by bipolar stimulation between two epidural needle electrodes. Potentials evoked by monopolar stimulation in the upper limbs were compared with those evoked in the lower limbs during the same stimulation procedure. RESULTS: Monopolar stimulation yielded equivalent and, if anything, more stable responses in the lower limbs. Recording in the upper limbs was satisfactory and allowed a decrease in responses to be detected in two patients. Acceptable thresholds for changes in amplitude relative to baseline were 40 % for upper limbs and 30 % for lower limbs. CONCLUSIONS: Monopolar stimulation can be used to monitor the spinal cord during surgery for scoliosis correction. This procedure is more convenient for the surgeon and allows for the combined recording of responses in all four limbs, which can be useful in the case of surgical techniques such as those involving a VEPTR.
PURPOSE: To assess the validity and utility of monopolar stimulation (between a peridural needle and a large adhesive anode placed in the sternal area) for intraoperative monitoring in scoliosis surgery. METHODS: This procedure was assessed during 41 operations involving either arthrodesis with posterior instrumentation or a Vertical Expandable Prosthetic Titanium Rib (VEPTR). Responses evoked by monopolar stimulation were compared with those evoked by bipolar stimulation between two epidural needle electrodes. Potentials evoked by monopolar stimulation in the upper limbs were compared with those evoked in the lower limbs during the same stimulation procedure. RESULTS: Monopolar stimulation yielded equivalent and, if anything, more stable responses in the lower limbs. Recording in the upper limbs was satisfactory and allowed a decrease in responses to be detected in two patients. Acceptable thresholds for changes in amplitude relative to baseline were 40 % for upper limbs and 30 % for lower limbs. CONCLUSIONS: Monopolar stimulation can be used to monitor the spinal cord during surgery for scoliosis correction. This procedure is more convenient for the surgeon and allows for the combined recording of responses in all four limbs, which can be useful in the case of surgical techniques such as those involving a VEPTR.
Authors: Ahmad Nassr; Annalise Noelle Larson; Benjamin Crane; Kim W Hammerberg; Peter F Sturm; Steven M Mardjetko Journal: J Pediatr Orthop Date: 2009 Jan-Feb Impact factor: 2.324