Abstracts

Rationale: The practice at Mayo Clinic for several years had been to perform a brain MRI three months following resective epilepsy surgery in addition to an EEG and other selected tests. The estimated per-exam fee, for MRI brain without contrast is $3543 and exam without and with contrast is $5175, based on the National Market Reference Point(NMRP) 85%ile. The value of a routine post surgical MRI has not been examined. Methods: Epilepsy surgery cases were obtained from a log of all electrocorticography (ECOG) studies performed at Mayo Clinic, Rochester. 173 patients underwent ECOG from 2006-2008. Of these, 76 were excluded (31=MRI not performed, 22=ECOG done as part of surgical mapping for brain tumor surgery, 23=surgical resection not done), leaving 97 patients. Preoperative MRI findings were categorized as lesional or non-lesional. Postoperative MRI findings were categorized as expected, unexpected clinically significant, or unexpected insignificant. Surgeries were categorized as temporal, extratemporal or both; and lesionectomy, corticectomy, or both. The electronic medical record (EMR) was reviewed to determine surgical outcome (seizure free, auras only, significant seizure reduction, or no reduction), and to identify unexpected postoperative neurological complaints and findings. Results: 97 patients underwent 98 surgeries. 52(54%) were male. Median age at time of surgery was 33.7 years (range 10-76 years). Median time between surgery and post-op routine MRI of the head was 105 days (range 38-364 days). 66(67.3%) surgeries were lesional (35=MTS) and 32(32.7%) non-lesional. 38(39%) surgeries were corticectomies, 4(4%) were lesionectomies and 56(57%) underwent a combined lesionectomy/ corticectomy. Postoperatively, 74(76.3%) of the patients were seizure free, 2(2.1%) reported continued auras, 12(12.3%) had a significant seizure reduction, and 9(9.3%) had no reduction. 3(3%) patients complained of headaches and 1(1%) complained of tingling in the fingers. In 96(98%) of the surgeries, the postoperative MRI showed expected findings. In 2(2%) surgeries, the postoperative MRI showed an unexpected clinically insignificant finding. One had a convexity extradural hematoma and one had a small region of infarction deep to the cortical resection. Conclusions: We did not demonstrate value for brain MRI as part of the routine post-surgical follow-up process and have since discontinued this practice. The charges for the studies performed during this study were equivalent to >$400,000 based on NRMP fee estimates. Value assessment of clinical processes is essential to identifying opportunities for cost effectiveness.