Anterior thoracic spinal cord herniation (ATSCH): surgical treatment and postoperative course. An individual patient data meta-analysis of 246 cases

BACKGROUND: Anterior thoracic spinal cord herniation (ATSCH) is a rare cause of progressive myelopathy. Early surgery is essential, but there is no agreement about the best surgical approach.

OBJECTIVE: To identify factors that determine surgical results, and to find evidence for the most favorable technique to correct ATSCH.

METHODS: To find relevant literature, computerized databases of PubMed, EMBASE, and ISI Web of Science were searched. The current study comprised case-reports published between 1974 and 2018, and the data-set was completed with 12 cases treated in our own institute. Patient characteristics were analyzed following the principles of an individual participant data (IPD) meta-analysis.

RESULTS: Brown-Séquard-like neurological deficit prior to surgery was associated with postoperative motor-function improvement when compared to patients with para-paresis (P=0.04). In the univariate analysis, widening of the dura defect (WDD) was more prevalent among improved patients, whereas anterior dura patch (ADP) and application of Intra Operative Neurophysiological Monitoring (IONM) were not. In the multivariate analysis the favorable association with WDD disappeared, which is explained by the dominant influence of a Brown-Séquard-like deficit on outcome.

CONCLUSIONS: In general, postoperative results after surgery for ATSCH are favorable, with a high percentage of patients experiencing postoperative improvement. Postoperative motor function improvement is more likely to occur in patients with a Brown-Séquard-like neurological deficit. The WDD should be favored above the application of a patch as the technique of choice in surgical treatment of ATSCH.