The effect from different numbers of segmental arteries ligation to the spinal cord in the clinical practice of posterior vertebral column resection correction.

PURPOSE: In using posterior vertebral column resection (PVCR) to treat severe kyphoscoliosis, it is unavoidable to ligate and cut off several segmental arteries (SAs) of the spinal cord for exposure and hemostasis, but which would raise the neurological risks. The aim of this study is to explore the changes of intraoperative spinal cord monitoring (IOM) following ligating different numbers of SAs in PVCR.

METHODS

Twenty-one consecutive patients with severe kyphoscoliosis were included and treated by PVCR correction. In operation, according to ligate different numbers of SAs, the IOM changes were recorded, respectively. Examinations of the covariance between different numbers of SAs ligations and IOM changes were performed to reveal the effect to the spinal cord by SAs ligations.

RESULTS

In all the 21 cases, averaging 1.9 pairs of SAs were ligated. With the increased numbers of ligations, SSEP amplitudes and latencies were changed more obviously: from 1 to 3 pairs ligations, the mean decreased percentages of amplitudes were from 53.20 to 78.15%, the mean increased percentages of latency were from 1.23 to 1.40%, and the mean durations of decreased SSEP amplitudes were from 3.23 to 5.2 min; but without abnormal MEP changes. None occurred postoperative or delayed neurological deficit. Correlation analysis identified significant correlations between the number of SAs ligation and decreased percentage of SSEP amplitude (r = 0.945, P < 0.0001), and between the number of SAs being ligated and the duration of SSEP change (r = 0.945, P = 0.0002).

CONCLUSIONS

Following the increased number of SAs ligation, the amplitude of SSEP is decreased more obviously with a much longer duration of recovery and the risk to spinal cord will be increased greatly. In the PVCR correction on the basis of spinal shortening, the numbers of SAs ligations should be as less as possible for neurological safety.