This is a retrospective, observational single-center study. The studies is to investigate the incidence of posterior epidural spinal hematoma(PSEH) and recognize the risk factors for it in a cohort of patients undergoing posterior thoracic surgery in isolation.

The study enrolled patients from January 2010 to December 2019, patients who developed PSEH after posterior thoracic surgery and underwent the hematoma evacuation. For each PSEH patients, 2 or 3 controls who did not develop the PSEH, underwent the same procedures of similar complexity at the same section of thoracic spine in the same period were collected. The preoperative and intraoperative factors, blood pressure related factors and radiographic parameters were collected to identify possible risk factors by comparing between two groups.

Inclusion Criteria:

Subjects satisfying the following criteria will be considered eligible for enrollment in this study:

1. Patient is ≥ 18 years and < 80 years of age;
2. Patient who received thoracic decompression surgery via posterior approach
3. Patient who diagnosed as symptomatic spinal epidural haematoma and received revision surgery.

Exclusion Criteria:

1. Thoracic spinal stenosis caused by trauma, tumor, infectious, deformity and other disease;
2. Symptomatic spinal epidural haematoma happened at cervicothoracic and thoracolumbar junction;
3. Initial surgeries were performed at other hospital;
4. Incomplete clinical data.

Between January 2010 and December 2019, 1612 patients were performed thoracic decompression surgery due to thoracic spinal stenosis (TSS) caused by thoracic disc herniation, ossification of posterior longitudinal ligament and ligamentum flavum with/without posterior instrumentation in our institution. The SSEH group patients were determined by symptom, MRI, intraoperative finding and underwent hematoma evacuation within one weeks of the initial surgery. For the control group, those who did not develop the SSEH, underwent the same procedures of similar complexity at the same section of thoracic spine in the same period (the same year or the following year) were randomly selected from the pool of patients.

We will make the clinical study report available for half a year after the publication of the results of the studys

The IPD will become available for half a year after the publication of the results of the study.

The IPD is available to the readers of the journal in which our research is published. The corresponding author of the published papers will review the requests