Trends in Functional Neurosurgery Procedures: Analysis of the Medicare Database 2000-2021

Introduction: Technological advancements and increasing indications have grown the number of procedures functional neurosurgeons perform. To date, no analysis has examined trends in the rates of functional procedures performed. The objective of this study is to characterize the number of functional neurosurgery procedures performed among the Medicare population from 2000 to 2021.

Methods: The American Medical Association Common Procedural Terminology manual was used to compile all procedures commonly performed by functional neurosurgeons. The Medicare Part B (MPB) National Summary data files were used to obtain procedural rates for deep brain stimulation and pulse generator replacement (DBS), trigeminal neuralgia treatment (TGN), cranial nerve stimulation (CNS), spinal cord stimulation (SCS), stereotactic/radiosurgery (SRS/RS), craniotomy for epilepsy monitoring (EM), and craniotomy for epilepsy treatment (ET).

Results: From 2000-2021, 795,517 functional procedures were billed to MPB. The annual number of procedures increased by 39,698 procedures (330.7%, p< 0.001) from 12,005 in 2000 to 51,703 in 2021. This change in annual volume varied by procedure type, with EM increasing from 1,720 procedures in 2000 to 4,453 procedures in 2021 (+2,733, +158.90%, p< 0.001), ET decreased from 316 procedures to 199 procedures (-177, -37.03%, p< 0.001), TGN decreased from 3,370 to 2,565 procedures (-805, -23.89%, p=0.119), SRS/RS increased from 2,773 to 11,887 in 2021 (+9,114, +328.67%, p< 0.001), DBS increased from 1,858 to 9,338 procedures in 2021 (+7,480, +402.58%, p< 0.001), CNS increased from 33 to 2,531 in 2021 (+2,498, +7,589.7%, (2011-2021: p=0.162), and SCS increased from 1,935 procedures in 2000 to 20,730 procedures in 2021 (+18,795, +971.3%,p < 0.001).

Conclusion : There has been an overall increase in functional neurosurgical procedures performed over the last two decades. Open approaches to epilepsy have been the only category to decrease in this time period. Spinal cord and cranial nerve stimulation have dramatically increased over this period, which may be indicative of other specialties using these codes for similar procedures.