Conus Medullaris Level Not Linked to CSF Leak Risk in Spinal Surgery, Finds Study
UK: A new study published in Apollo Medicine has explored whether the anatomical level of the conus medullaris influences the likelihood of cerebrospinal fluid (CSF) leaks during spinal surgery, a complication that can significantly affect patient outcomes.
The investigation, led by Dr. Rajesh Botchu from the Department of Musculoskeletal Radiology at the Royal Orthopaedic Hospital, Birmingham, UK, and colleagues, retrospectively assessed 55 patients who experienced post-operative CSF leaks. Patient records and MRI scans were reviewed, with cases stratified by spinal pathology, age, and sex.
The analysis revealed several interesting trends. Patients who developed CSF leaks were more frequently operated on for disc pathologies compared with spinal stenosis. Those with spinal stenosis were generally older, and women were more represented in the CSF leak group. A noteworthy finding was that patients with disc pathologies typically had a higher conus level than those with spinal stenosis. Importantly, none of the patients with low-lying conus (at or below L3) experienced a CSF leak.
Despite these observations, the study concluded that there was no direct correlation between the conus level and the risk of CSF leaks. Instead, incidental durotomies and CSF leaks remain important concerns in spinal surgery, where factors beyond the conus level may play a more influential role.
Commenting on the study, Dr. Rajesh Botchu told Medical Dialogues, “The level of conus is important and should be included in the MRI. Spinal surgeons need to be aware of the level of conus, as a low-level conus might result in increased morbidity.”
When asked about the significance of conus level assessment before surgery, Dr. Botchu noted, “There is a theoretical risk of increased dural tears and CSF leaks in patients with low-lying conus.” However, he emphasized that the findings of the current study suggest otherwise. “Our study shows that surgical technique is an important factor for CSF leaks, and the level of conus is not an important factor,” he clarified.
Dr. Botchu further highlighted revision surgeries as a major risk factor for intraoperative CSF leaks. “The main risk factor I feel is in revision surgery,” he explained.
On practical measures to minimize this complication, he stressed the importance of surgical precision and patient awareness. “Surgeons should be aware of high-risk patients, particularly those undergoing revision discectomies, and ensure meticulous dissection of the dura,” he advised.
The findings underline the complexity of CSF leak risk in spinal surgery. While anatomical considerations like conus level may not directly influence incidence, the importance of refined surgical technique and risk stratification cannot be overstated.
By highlighting that conus level may not be a determining factor, the study encourages surgeons to focus on modifiable elements—particularly careful handling during revision surgeries—to reduce morbidity linked to CSF leaks.
"The research adds to the growing body of literature aimed at improving surgical outcomes in spine care and reinforces the role of tailored surgical approaches based on patient-specific risk profiles," the authors concluded.
Reference:
Kennedy, R., Ali, A., Hughes, S., Hassan, F., & Botchu, R. Does the Level of the Conus Medullaris Affect CSF Leak Incidence During Spinal Surgery? Apollo Medicine. https://doi.org/10.1177/09760016241305066
