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The Feasibility and Efficacy of Intraoperative Neural Monitoring in Developing Countries. H.B. Calder, Ph.D. Biotronic Ann Arbor, MI. Humanitarian Neural Monitoring With NGO Surgical Excursions.
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The Feasibility and Efficacy of Intraoperative Neural Monitoring in Developing Countries H.B. Calder, Ph.D. Biotronic Ann Arbor, MI
Humanitarian Neural Monitoring With NGO Surgical Excursions • It is common for surgeons to be invited to provide surgical services in developing countries through non-governmental agencies (NGO’s). • We feel this is an excellent means of giving back to the world community with like-kind contributions.
The Need for Neural Monitoring in Global Outreach Programs • These pool of patients for which surgeries are performed require the most complex procedures • Spinal cord injuries are certain to happen given enough surgeries.
Most of the events will involve ischemic mechanisms rather than trauma. Immediate intervention can be very successful. • With a tortuous spinal column there may be multiple incidents, so a single evaluation of function such as the wake up test will not be timely. • Neural monitoring in some countries will certainly be as unavailable as surgical skills.
These cases may involve surgical approaches that involve new and unknown risks. • There is not time to do staged procedures. • There may not be a full armamentarium of instrumentation available. The surgical team is ad hoc. • You depend upon the local nursing and anesthesia support team. Therefore there is a higher risk of neurological events than you would find with your “home” team in an environment used to doing these procedures. • You need to know about neural status at all times.
The Timeliness of Neural Monitoring Information is Valuable • The immediate feedback of neural monitoring may help modify the surgical approach. • We have learned that combined anterior/posterior approaches are associated with a much higher risk of spinal cord ischemia. • The conventional technique of vertebrectomy for kyphosis is associated with increased risk of spinal cord injury.
Experience With Neural Monitoring in FOCOS patients 1999-2005 • 98 FOCOS Patients who underwent spinal deformity surgery in Ghana or Barbados • Scoliosis surgeries 67 • Kyphosis surgeries 31 Study Sample
Methods • SSEP and TcMEP monitoring were performed on every patient in the sample after 2000 and reliable responses from one or both modalities were obtained for all patients. • SSEP and TcMEP monitoring was performed according to ASNM guidelines • TcMEP and SSEP 88 • SSEP monitoring only (Prior to 2000) 9 • TcMEP only 1 • Small percent of patients were also monitored using H-Reflex responses. These data were not included in the analysis for this study
Methods, cont. • Anesthesia: • Generally, TIVA was used on all patients • NMB maintained at 2/4 twitches or better • Determination of significant changes: • SSEP: 50% amplitude reduction, 10% latency increase, or a significant change from baseline • TcMEP: interventions involved loss of response from steady state
Findings: Big Picture • Total Patients Monitored 98 • Significant changes 25 (25.5%) • SSEP and TcMEP changes 16 (64%)* • SSEP changes only 4 (16%)* • TcMEP changes only 5 (20%)* *Percent of all patients with interventions (25)
Interventions as a Function of Pathology Interventions as a percentage of patients in group
Interventions as a Function of Curve Angle Mean Curve Angle *Significant at <.05
Outcomes • No patients had permanent paraplegia. • 3 patients had transient paraplegia which partially resolved to the point of ambulation. • 1 patient had a long-term foot drop.
Conclusions • The degree of spinal deformity encountered in these populations is unusually severe • The inherent risk of intraoperative neural compromise (25.5% in this sample) dictates that neural protection be part of every international outreach program • Risk of neural compromise increases with complexity of surgery • Risk of injury increases with increased curve angle for scoliosis patients • Risk of neural compromise is especially high for kyphosis surgeries • A full complement of neurophysiological monitoring modalities can be reliably provided in developing countries
Staffing for Neural Monitoring • Montoring volunteers should have a minimum credential of CNIM with extensive experience in spinal cord monitoring (not pedicle screw stimulation)0 • These are altruistic individuals who would be happy to join your team. • Give them plenty of notice
Professional Support for Neural Monitoring The American Society of Neurophysiological Monitoring has constituted a global outreach committee to ecourage its members become involved in international philanthropic activities. ASNM.org
Sophisticated and Compact Equipment is Available • Neural monitoring equipment has evolved to compact PC based systems. • A modern portable system can perform all modalities of neural monitoring including SSEP, TCMEP, EMG, and Reflexes. • Equipment is no longer a barrier.
Costs for Neural Monitoring • The benefits are unquestionably greater than the costs. • Many technicians are interested in being involved in an outreach program. Most of them would be delighted to cover some or all of the cost of their trips as part of their philanthropic endeavors. • Often their employer is willing to cover their activity. We are covering the salaries and expenses for twelve weeks of global outreach services. Many of my peers are doing the same. your endeavors if • The cost to your program many be minimal. Usually just housing and food
Poor Countries – Not Poor Medicine • These excursions should have the highest quality of surgical services – including neural monitoring.