Perioperative Outcomes of Spinal Cord Stimulator Placement in Patients with Complex Regional Pain Syndrome Compared with Patients without Complex Regional Pain Syndrome

Abstract

Complex regional pain syndrome (CRPS) is a multifaceted disorder resulting in an abnormal pain response to tissue injury. Among key CRPS features are neurogenic inflammation, maladaptive plasticity, and vasomotor dysfunction, which can result in severe pain and disability. Spinal cord stimulation (SCS) is an efficacious treatment for several chronic pain conditions and may improve pain and life quality in CRPS patients with CRPS. However, little information exists regarding perioperative outcomes of patients with CRPS undergoing surgical implantation of an SCS device. Patients were included if they underwent an SCS procedure at our institution between 2008 and 2016 for chronic pain. Cases were excluded if the procedure involved stimulator removal or if it was an outpatient procedure. Multivariate regression assessed the effect of CRPS and other clinical variables on perioperative outcomes. Eighty-one inpatient SCS implantation cases for chronic pain were included, with 9 patients (11.1%) having a CRPS diagnosis. The CRPS cohort received higher mean quantities of intraoperative opioids and had a lower proportion of patients reporting meaningful pain reduction (16.7%) in the 24-hour postoperative setting compared with patients without CRPS (35.9%), although this was not statistically significant. Multivariate regression modeling suggested that CRPS was a significant predictor of increased odds of extended time to the postanesthesia care unit discharge (P= 0.0406) and higher direct costs of hospitalization (P= 0.0326). Our data suggest that CRPS may pose several unique risks in the perioperative period after inpatient SCS implantation. These findings support the need for future prospective investigations examining risks and outcomes for SCS procedures in this population.