Time spent per patient in lumbar spinal stenosis surgery

To examine the time needed from a surgeon's viewpoint to treat a patient operated for lumbar spinal stenosis. We firstly aimed to give evidence of the wide ranging duration of standardized procedure. Secondly, we investigated factors affecting the time allocated to each patient.

438 medical records of patients operated on for lumbar decompression without fusion (2005-2011) were retrospectively examined. Primary data were operative time (OT, min), length of stay (LoS, days) and number of postoperative visits. A fourth parameter was calculated, the time spent per patient (TSPP, min) by summing the time spent in surgery, during inpatient and outpatient follow-up visits. Factors that influenced these medical resources were examined.

Median (5th-95th percentile) LoS was 5 days (2-15), OT 106 min (60-194), number of medical visits 5 (2-11) and TSPP 329 min (206-533). In descending order, factors predicting LoS were age, no. of levels, sex, operative technique, cardiovascular risk index, dural tear and haematoma. Factors predicting OT were number of levels, dural tear, foraminotomy, synovial cyst and body mass index. The statistical model could predict 36% of the TSPP variance. We recommend that surgeons add 35 min for each level, 29 min for patients over 65 years, 30 min for women, 132 min for dural tear and 108 min for epidural haematoma.

TSPP treated for lumbar spinal stenosis is highly variable, yet partially predictable. These data may help individual surgeons or heads of departments to plan their activities.