Intraoperative Neural Mobility and Postoperative Neurological Recovery in Anterior Cervical Decompression Surgery: Evaluation With Intraoperative Sonography.

STUDY DESIGN

A study using intraoperative sonography (IOS) was conducted for evaluating neural mobility in anterior cervical decompression surgery.

OBJECTIVES

To analyze decompression status and mobility of the spinal cord and the nerve root during anterior cervical decompression and to clarify its relevance to the postoperative neurological recovery.

SUMMARY OF BACKGROUND DATA

Several papers introduced the usefulness of IOS assessments; however, there have been no reports systematically evaluating the neural mobility in anterior cervical decompression surgery.

METHODS

Eighty-four consecutive patients with compressive myelopathy who underwent anterior cervical decompression procedures were studied. The decompression status of the spinal cord was evaluated with IOS and classified into 3 grades according to the restoration pattern of the space ventral to the cord. Pulsatile motion of the spinal cord in cranio-caudal direction was named "sliding pulsation" and graded into 3 groups. The nerve root pulsation was also assessed using the IOS short-axis views. This study analyzed whether those neural mobility in anterior cervical decompression surgery had relevance to postoperative neurological recovery, which was assessed by the Japan Orthopaedic Association score.

RESULTS

The mean recovery rate of the Japan Orthopaedic Association score was 59.1% in total. According to the decompression status in IOS, 67 patients who acquired space ventral to the spinal cord indicated 64.3% of the recovery rate which was significantly higher than 36.6% of the other patients on an average. As to the sliding pulsation of the cord, 10 patients who failed to show this particular motion indicated significantly lower recovery rate as 36.9%. In addition, 6 patients who did not exhibit nerve root pulsation indicated just 29.3% of recovery rate, and 4 of them failed to show the cord sliding motion.

CONCLUSIONS

Sonographic evaluation during anterior cervical decompression surgery provided very useful information of neural decompression status that had significant correlation with postoperative neurological recovery.