Intra-operative imaging for spinal level localisation in lumbar surgery.

Retrospective review of the practice of 3 surgeons in a single centre during a 1-year period. We aimed to investigate our adherence to the Society of British Neurological Surgeons (SBNS) guidelines regarding intra-operative imaging during lumbar surgery and to determine if this has any impact on length of surgery or complications rates, in particular rates of wrong-level surgery. The SBNS recommends three x-rays for intra-operative spinal localisation - one prior to incision, the second after exposure of the laminae and before the commencement of decompression, and the third at the end of the operation to confirm the adequacy of decompression. At our centre, surgeon A performs x-rays 1 and 3 routinely, and x-ray 2 in cases where the anatomy is uncertain, surgeon B performs x-ray 2 only, and the practice of surgeon C varies depending on the complexity of cases. We reviewed the surgical logbooks of 3 consultant neurosurgeons in our centre for the 1-year period between October 2015 and October 2016. Our study included 301 patients who had undergone lumbar decompression or lumbar discectomy during this period. There were no cases of wrong-level surgery. The incorrect spinal level was initially exposed in 13 cases (4.3%). 10 of these had x-ray 2 only, 1 had x-ray 1, 1 had x-rays 1 and 2, and 1 had all 3 x-rays. Surgeon B performed 8 of these cases, four were performed by surgeon C, and 1 by surgeon A. The median duration of surgery was 80 minutes for lumbar decompression and 67.5 minutes for lumbar discectomy. The median duration of surgery in patients in whom the wrong level was initially exposed was 85 minutes for lumbar decompression and 80 minutes for lumbar discectomy. Performance of the 3 recommended x-rays may increase the identification of wrong-level exposures before the commencement of decompression and may reduce the length of surgery.