Imagine undergoing a complex spinal procedure with the assurance that any potential nerve damage can be detected and corrected in real-time. That's the premise of a groundbreaking new study from Houston Methodist Hospital that could revolutionize the way spinal surgeries are monitored.

The research highlights transabdominal motor evoked potential (MEP) neuromonitoring, a novel technique that measures electrical activity in peripheral nerves and muscles by directly stimulating the inferior aspect of the spinal cord, bypassing the brain and the effects of general anesthesia.

"In spinal surgeries, particularly those involving the lower back, there is a significant risk of impacting nerves critical to mobility and overall quality of life," said Dr. Comron Saifi, the C. James and Carole Walter Looke Chair in Orthopedic Spine Surgery at Houston Methodist Hospital and principal investigator of the study. "Our primary objective is to treat the patient's spine related pain and dysfunction in the safest way possible. To achieve this, it is imperative to utilize a reliable method for monitoring the integrity of the patient's nerves, particularly during complex spine procedures."

In 2022, Houston Methodist became the first known program to adopt the novel transabdominal MEP technique for lumbosacral spine surgery and has now published the first peer-reviewed study comparing this technique to the standard transcranial MEP approach.

"Transcranial neuromonitoring of the lumbar spine presents limitations, largely due to false positives and negatives influenced by anesthesia, blood pressure and other patient-specific factors," noted Dr. Saifi.

False positives can lead to unnecessary additional surgical interventions, extending operation times and increasing patient exposure to anesthesia. Conversely, false negatives can result in undetected nerve damage until after the surgery.

Dr. Saifi and colleagues at Houston Methodist sought a more reliable method that bypasses the brain, directly stimulating the inferior aspect of the spinal cord.

This transabdominal approach avoids the interference of anesthesia and other systemic factors affecting the central nervous system.

The study, which monitored 220 patients undergoing spinal fusion surgery using both transcranial and transabdominal neuromonitoring techniques, found the transabdominal method to be significantly more reliable. The key findings include:

• Baseline reliability: Transabdominal MEP achieved 99.6% reliability in baseline muscle activation compared to 89.8% for transcranial MEP
• False positives: The transabdominal technique had a false positive rate of just 1.4%, significantly lower than the 11% observed with transcranial MEP
• True positives: The transabdominal approach detected three true positives missed by the transcranial system
• Quality and accuracy: During 40 random spot tests, the quality and accuracy of data provided by the transabdominal method matched or exceeded that of the transcranial approach

Dr. Saifi emphasized that this study is the first of its kind to directly compare these two neuromonitoring techniques in spine surgery. The results suggest that transabdominal MEP could establish a new standard of care for lumbosacral spine surgery, offering a more accurate and effective solution for intraoperative monitoring.

This advancement could have significant implications for patient safety and surgical outcomes. By reducing false positives, surgeons can avoid unnecessary procedures and prolonged operation times. The improved accuracy of the transabdominal method also ensures that genuine neurological concerns are identified and addressed in real-time during surgery.

"By enhancing the reliability and precision of intraoperative monitoring, this novel technique has the potential to reduce surgical risks and improve patient outcomes, representing a substantial advancement in the field of spine surgery," said Dr. Saifi, who credits the study's success to the strong multidisciplinary collaboration at Houston Methodist.

The 220 cases included in the research were conducted by a team of eight spine surgeons, five board-certified neurophysiologists and seven neurologists — an exceptionally robust assembly of expertise for a study on a novel surgical technique.

"This is the embodiment of our motto, 'Leading Medicine,'" Dr. Saifi explained. "It requires substantial effort to innovate in surgical practices and even greater dedication to rigorously study and advocate for widespread adoption. However, the potential to fundamentally improve patient care and outcomes on a larger scale is what drives us."

Moving forward, the team plans to conduct further studies to solidify these findings and explore additional applications of transabdominal MEP in various types of spinal surgeries. They hope that these efforts will lead to the widespread adoption of the technique, ultimately elevating global standards of surgical care.