Symptomatic retethering of the spinal cord in postoperative lipomyelomeningocele patients: a meta-analysis

Background: Timing of surgical treatment for tethered cord syndrome due to a lipomyelomeningocele (LMM) has been controversial. The purpose of this study was to evaluate populations of patients treated surgically for LMM in a meta-analysis in order to better understand how outcomes differ based on follow-up time, symptomatology, and LMM classification.

Methods: An extensive search on PubMed and Google Scholar was performed for LMM and surgical outcomes to identify case series of patients for inclusion in this analysis. Patients were sorted based upon symptomatology prior to surgery and Chapman’s LMM classification, where possible. Deterioration rates were determined by symptomatic retethering of the spinal cord that led to repeat surgery.

Results: Of 608 (19 %) patients, 115 were included in the study experienced deterioration leading to repeat surgery. Symptomatic and asymptomatic patients did not experience significantly different rates of deterioration after surgical untethering. There was a significant positive linear correlation between follow-up time of studies and percentage of patients deteriorating with an increase of 3.3 % per year of follow-up. Transitional LMM had a significantly higher rate of deterioration compared to the caudal type along with the entire patient pool.

Conclusions: Outcomes of primary surgical treatment in regard to late deterioration are not significantly affected by patient symptomatology. Patient deterioration increases linearly over time. Additional studies should be performed to adequately determine the natural history of asymptomatic patients that are treated conservatively for LMM.