Ranjith Babu, MS 1 Jonathan Choi, MD 1 Adam Back, MD 1 Vijay Agarwal, MD 1 Matthew Hazzard, MD 1 Beatrice Ugiliweneza, MSPH PhD 2 Chirag G. Patil, MD MS 3 Maxwell Boakye, MD 2 Nandan Lad, MD PhD 1 1)Division of Neurosurgery, Duke University Medical Center 2)Center for Advanced Neurosurgery, University of Louisville 3)Center for Neurosurgical Outcomes Research, Cedars-Sinai Medical Center Underutilization of Spinal Cord Stimulation in Patients with Failed Back Surgery Syndrome

FAILED BACK SURGERY SYNDROME (FBSS) FBSS affects 5-40% of all patients who undergo lumbosacral spine surgery for back pain. Treatment options include conventional medical management, repeat lumbar surgery, or spinal cord stimulation (SCS). The goal of this study was to determine real world utilization of SCS and compare complications, charges, and healthcare resource use in a large, independent cohort of FBSS patients undergoing surgical intervention.

METHODS Patients 18 years and older with a diagnosis of FBSS or post- laminectomy pain syndrome who underwent SCS or lumbar surgery: N = 16,455 All patients: N = 16,455Matched Patients with > 2 years post-operative enrollment: N = 222 Lumbar Surgery N = 16,060 SCS N = 395 Lumbar Surgery N = 111 SCS N = 111

CHARACTERISTICS FOR ALL PATIENTS Lumbar ReoperationSCSp-value Age [mean(SD)]54 (13)54 (12) Gender (female)55.3%63.8% Charlson index %77.7% 112.4%18.0% 22.9%2.0% >=31.0%2.3% Type of insurance < Commercial71.8%65.1% Medicaid7.5%19.0% Medicare20.7%16.0%

POSTOPERATIVE COMPLICATIONS OF PATIENTS UNDERGOING LUMBAR REOPERATION FOR SCS Complications Lumbar ReoperationSCSp-value Index Hospitalization1886 (11.7%)20 (5.1%)< days2225 (14.4%)25 (6.7%)< days2074 (14.4%)22 (6.5%)<0.0001

HEALTHCARE RESOURCES USED IN MATCHED PATIENTS WITH TWO YEARS FOLLOW-UP Lumbar ReoperationSCSp-value Hospital DaysIndex Hosp3 (2)2 (1)<0.0001* mean (SD)Post-op 2yr3 (6)4 (9) Hospital chargesIndex Hosp40,433 (32240)31,210 (27327)0.0162* Post-op 2yr15,150 (39268)19,972 (44086) Outpatient chargesPost-op 2yr20,210 (23334)20,156 (20672) ER chargesPost-op 2yr765 (1808)815 (1454) Medication ChargesPost-op 2yr5,766 (7462)9,332 (13218) Total costs2 years82,586 (66154)80,669 (68575)0.8772

In the PROCESS trial, 100 FBSS patients underwent SCS or conventional medical management (CMM). 47% of SCS patients and 7% of CMM patients achieved 50% or greater relief of leg pain at 2 years. In a trial by North et al, 50 patients underwent either SCS or lumbar reoperation. 47% of SCS patients and 12% of lumbar reoperation patients achieved at least 50% pain relief. SCS EFFICACY IN PRIOR RANDOMIZED CONTROLLED TRIALS

Our data shows that at 90 day follow-up, the SCS group has a lower complication rate than lumbar surgery (6.5% vs. 14.4%). At 2 years, the overall healthcare costs are similar in the SCS and lumbar reoperation groups. COMPLICATION RATES AND COST

Despite increased efficacy, decreased complication rate, and equivalent costs, only 2.4% of 16,455 patients undergoing surgical treatment for FBSS had SCS in the studied cohort. This may be due to SCS being perceived as a salvage operation, with patients undergoing many reoperations prior to being referred for SCS. Nonetheless, the low market penetration suggests that there is significant room for growth. ONLY A SMALL FRACTION RECEIVE SCS

This is the largest study to date comparing SCS to lumbar reoperation, demonstrating SCS to have a lower complication rate, shorter hospital stay, and comparable overall healthcare costs. Additional objective studies are needed to increase awareness of the benefits of SCS for the treatment of chronic pain syndromes such as FBSS. CONCLUSION

Thank you Acknowledgements Duke Neurosurgical Outcomes Center Nandan Lad, MD PhD