Posterior Thoracic Corpectomies with Cage Reconstruction for Metastatic Spinal Tumors: Comparing the Mini-Open Approach to the Open Approach

Presented at SMISS Annual Forum 2014
By Darryl Lau MD
With Dean Chou MD,

Disclosures: Darryl Lau MD None Dean Chou MD None,

Introduction:
Spinal metastases most commonly affect the vertebral bodies of the spinal column, and spinal cord compression is an indication for surgery. Commonly, an open posterior approach is taken to perform a transpedicular, costotransversectomy, or lateral- extracavitary corpectomy. As life expectancies are short with metastatic spinal disease, decreasing the morbidity of surgical treatment is critical. One potential approach to decreasing morbidity is utilizing minimally invasive surgery.

Aims/Objectives:
This study compares outcomes of patients who undergo mini-open vs. traditional open transpedicular corpectomy for spinal metastases in the thoracic spine.

Methods:
A consecutive cohort from 2006 to 2013 of 49 adult patients who underwent transpedicular corpectomies in the thoracic spine for spinal metastases was retrospectively identified. Patients were categorized into open surgery and mini-open surgery. The mini-open transpedicular corpectomy was performed with a midline facial incision only over the corpectomy level of interest and percutaneous instrumentation above and below that level. The open procedure consisted of a traditional posterior transpedicular corpectomy. Chi-square test and two-tailed t-test were employed to compare perioperative and follow-up outcomes between the two groups.

Results:
In the analysis, 21 patients had mini-open surgery, and 28 patients had open surgery. The mean age was 57.9 years, and 59.2% were male. There were no significant differences in demographics, comorbidities, tumor type, neurological status (ASIA score), number of corpectomies performed, and number of levels instrumented between the two groups. The open group had a mean operative time of 413.6 minutes, and the mini-open group had a mean operative time of 452.4 minutes (p=0.329). Compared to the open group, the mini-open group had significantly less blood loss (917.7 cc vs. 1697.3 cc, p=0.019) and a significantly shorter hospital stay (11.4 days vs. 7.4 days, p=0.001). There was a trend towards a lower perioperative complication rate in the mini-open group (9.5%) compared to the open group (21.4%), but this was not statistically significant (p=0.265). At follow-up, there were no significant differences in ASIA score (p=0.342), complication rate after the 30-day postoperative period (p=0.999), or need for surgical revision (p=0.803). The open approach had a higher overall infection rate of 17.9% compared to the mini-open approach (9.5%), but this was not statistically significant (p=0.409).

Conclusions:
The mini-open transpedicular corpectomy is associated with less blood loss and shorter hospital stay compared to open transpedicular corpectomy. The mini-open corpectomy also trended towards a lower infection and complication rates, but these did not reach statistical significance.