Conservative management of asymptomatic spinal lipomas of the conus.

Objective: The natural history of spinal lipomas of the conus (SLCs) has not been well studied. Because of disappointing long-term results with early surgical treatment of asymptomatic children with SLCs, we have followed a protocol of conservative management for these patients. The results are presented in this report.

Methods: Since 1994, all asymptomatic children with SLCs who were examined at Necker-Enfants Malades Hospital were subject to a protocol of conservative management. The records for those patients were reviewed, to determine the incidence and timing of neurological deterioration. The findings were compared with those for a previously reported historical cohort of asymptomatic patients who underwent early surgery at our institution.

Results: Fifty-three asymptomatic children (35 girls and 18 boys) with SLCs were monitored, with conservative management. During a mean follow-up period of 4.4 years (range, 12 mo to 9 yr), 13 patients (25%) exhibited neurological deterioration. At 9 years, the actuarial risks of deterioration, as determined with the Kaplan-Meier method, were 33% for the conservatively treated patients and 46% for the surgically treated patients. With a Cox proportional-hazards model, there was no significant difference in the risks of neurological deterioration for patients who were treated conservatively and those who underwent early surgery.

Conclusion: The incidences and patterns of neurological deterioration seemed to be very similar, regardless of whether early surgery was performed. These results suggest that conservative treatment of asymptomatic patients is a reasonable option. A more definitive randomized study will be required to clarify the relative efficacy of early surgery for SLCs among asymptomatic patients.