Resumption of ambulatory status after surgery for nonambulatory patients with epidural spinal metastasis

Background context: Improving the surgical outcome of nonambulatory patients with metastatic epidural spinal compression has been of great interest lately. Although there have been many reports regarding the surgical outcome of spinal metastasis, the surgical outcome in terms of the probability of operative success for nonambulatory patients has not been thoroughly described. If the probability of ambulatory recovery is known, the optimal surgical indications can be determined and implemented.

Purpose: To predict the surgical outcome and probability of ambulatory resumption for nonambulatory patients with spinal metastasis.

Study design: Retrospective analysis.

Patient sample: The surgical outcomes of patients who could not ambulate independently because of spinal metastasis from 1987 to 2010 were analyzed.

Outcome measures: The primary end point was postoperative ambulatory status. The secondary end point was survival time.

Methods: Fifty-seven patients who could not ambulate independently at the time of surgery were included in the study. We defined "independent ambulation" as a better functional status than Nurick Grade 3, which is defined as "difficulty in walking which was not so severe as to require someone's help to walk." Preoperatively, functional status was Nurick Grade 4 in 21 patients and Grade 5 in 36 patients. Weakness developed 10.5 ± 11.9 days (median, 7.0; range, 1-80) before the operation and steadily worsened. Patients were unable to walk starting from 3.6 ± 4.9 days (median, 1.8; range, 0.5-23) before the operation. The spinal metastases were circumferentially decompressed.

Results: Postoperatively, 39 patients (68%) could walk. Complications occurred in 26% (15/57) of the patients, and the major complication rate was 12% (7/57). The mortality rate was 5% (3/57). The patient survival time was 287 ± 51 days (median, 128) after the operation. Postoperative ambulatory status (yes vs. no, p < .01) and occurrence of major complication (yes vs. no, p < .01) affected survival time. Overall, patients could walk for 193±41 days (median, 114) postoperatively. Motor grade (grade ≥ 4/5 vs. <4/5, p < .01) and the occurrence of a major complication (yes vs. no, p < .01) were significant factors for resumption of ambulation. The rate of ambulation resumption was 95% (20/21) in patients with a motor grade of 4 of 5, whereas it was 53% (19/36) in patients with a motor grade less than 4 of 5 (p < .01).

Conclusions: The survival time of nonambulatory patients was dependent on ambulation recovery. About 95% of the nonambulatory patients could walk after surgery, when the operation was done in a timely manner with good remaining motor function. However, given the short life expectancy and the considerable surgical complication rate, surgery should only be prudently recommended to patients with optimal indications.