Outcomes of Major Peri-Operative Neurologic Complications in Paediatric Spinal Deformity Surgery

Study Design: Retrospective review of patient charts and x-rays. Objective. To learn more about the associations and outcomes of major intra-operative neurologic deficits in paediatric spine deformity patients. Summary of Background Data. Factors in the literature linked with deficits include: kyphotic deformities, combined anterior and posterior surgery, implant factors, hypotensive anaesthesia, and vascular aetiology.

Methods: A spinal patient data-base at a paediatric medical center with a high volume of spinal surgery identified patients developing major neurological deficits during or shortly following corrective spine surgery. Only elective procedures were included, no trauma or tumour cases. Excluded also were operations in the region of the cauda equina or cases developing peripheral nerve problems. Factors reviewed included preoperative patient characteristics, intra and post-operative course, vital signs, blood work, surgical approaches, management of the neurologic complication, and long-term outcomes. X-rays were reviewed for extent of curve correction and distraction.

Results: Fourteen cases of neurologic deficit (92% complete bilateral motor, variable sensory) were identified, including seven girls and seven boys (average age 11.9 years) who presented with the following deformities: congenital scoliosis, four cases; kyphoscoliosis related to spondyloepiphyseal dysplasia, four cases; adolescent idiopathic scoliosis, three cases; syndrome related kyphoscoliosis, two cases; and one case of post-laminectomy kyphosis. Average followup was 5.9 years. Eight of fourteen cases had combined anterior and posterior approaches with half staged. In 5/14 cases deficits were discovered intra-operatively (SSEP and Stagnara wake-up tests) and two cases were first noted on patient arrival from the OR to the ICU after normal SSEP's and one normal wakeup test and one "equivocal" wakeup test. Seven of fourteen cases were delayed onset neurologic deficits beginning on average 32.9 hours post-operation (range 20 - 72 hours). Findings at re-operation showed one strut graft possibly placed too tightly causing acute stenosis, and one of tenting of the cord over the kyphotic apex. No direct cord injuries occurred during surgery. In 12/14 urgent re-operations after instrumentation was removed and curves released, when subsequent decompression of the dura occurred the dura was noted to be non-pulsatile, followed by a visual return of pulsation of the dura with decompression. One patient died following re-operation of an unusual, syndrome-related brain swelling. Two patients had full neurological recovery and 10 of 14 had remarkable motor recovery but were ultimately left with some residual motor deficit and almost always a bladder function problem.

Conclusions: Characteristics associated with major peri-operative neurologic deficits included congenital spine defomities, spinal stenosis with bone dysplasias, and combined anterior and posterior procedures. Intra-operative SSEP monitoring failed to detect two immediate postoperative paralyses. Half of the major peri-operative neurological deficits were of delayed onset, suggesting that close monitoring should continue postoperatively. The majority of patients will have major motor recovery but few will have complete recovery.