Routine postoperative imaging early after lumbar decompression surgery: a prospective evaluation.

STUDY

DESIGN

Prospective cohort study.

OBJECTIVE

To determine the value of routine postoperative magnetic resonance imaging early after lumbar decompression in patients with nonspecific symptoms.

SUMMARY OF BACKGROUND DATA: Imaging after lumbar surgery may be performed more readily in patients even with nonspecific symptoms and without neurological deficit.

METHODS

Patients undergoing elective lumbar decompression surgery completed standardized questionnaires, were assessed neurologically on admission, and underwent magnetic resonance scanning within 72 hours after surgery. Residual stenosis was graded as absent or mild (outcome A) or moderate to severe (outcome B). Surgical technique and intraoperative complications and postoperative neurological status were recorded.

RESULTS

We recruited 28 consecutive patients who reported significant improvement in preoperative symptoms. In two-thirds of all patients, postoperative images showed at least one segment with moderate or severe residual stenosis (outcome B). Radiological outcome did not correlate with postoperative pain. Patient satisfaction index was comparable in groups A and B. The cross section of the spinal canal was significantly wider with a drain in situ. This did not, however, translate into a difference in overall visual analogue scale score or wound discomfort. Patients tended to report more back and leg pain with drains and were less satisfied with the result of the operation.

CONCLUSION

Early postoperative magnetic resonance scans in patients with nonspecific symptoms frequently show radiologically relevant stenosis, which is associated with neither outcome nor patient satisfaction. Drain placement is associated with less radiological narrowing but with lower patient satisfaction. Imaging without clinical correlate may yield nondiscriminatory information likely to unsettle and puzzle both patients and health care providers.

LEVEL OF EVIDENCE: 3.