SURVIVAL AND COMPLICATIONS FOLLOWING SURGERY FOR SPINAL METASTASES: A POPULATION BASED STUDY

Abstract

A province-wide study designed to use administrative data to determine the rate of post-operative complications, the survival duration and predictors of outcome among patients undergoing surgery for metastatic disease of the spine.

Surgery for patients with spinal metastasis is primarily palliative. It is often fraught with complications, which may in fact diminish quality of life. Quantification of survival rates and the risk of potential complications following surgery is important to the clinician and the patient’s families for decision making.

All patients that underwent surgery for spinal metastasis between 1991 and 1998 were identified using the Ontario health insurance database and a hospital discharge registry.

The mean age at surgery was 60. 3 years (range: 13–92 years). The mortality files identified patients who were dead by October 1999. Information about individual inpatient admissions including post-operative complications was then collected. The survival rates and complications following surgery were quantified and the effect of several variables on these two parameters was computed.

The median and mean survival was 227 days and 793. 4 days respectively. The 30-day and 3-month mortality were 9% and 29% respectively. Advanced age at surgery, male sex, presence of a pre-operative neurological deficit and primary cancers of lung, gastrointestinal tract & melanoma are predictive of poor survival. 39% patients had complications. Pre-operative neurological deficit was associated with a 71% higher risk of developing post-op. wound infection.

In the past, surgery has been recommended in patients with an anticipated survival of at least three to six months. The current study shows that even patients preselected on the basis of predictions of longer survival, there is a potential for early mortality and significant complications. Hence, a careful estimation of the benefits of surgery versus surgery related morbidity must be made prior to offering surgery for palliation.