Background: There is abundant literature on the long-term complications of intrathecal pumps (ITP), spinal cord stimulators (SCS), and peripheral nerve stimulators (PNS) used in the treatment of chronic pain. There is less information, however, on the perioperative complications of these procedures.
Objective: Exploration of the perioperative outcomes of implantable pain devices.
Study design: Observational study.
Setting: University hospitals, community hospitals, specialty hospitals, attached surgery centers, and freestanding surgery centers
Methods: Data were obtained from the National Anesthesia Clinical Outcomes Registry (NACOR) of the Anesthesia Quality Institute (AQI). Information was collected on patient demographics, procedure information, anesthetic administered, diagnosis linked to the procedure, and perioperative outcomes.
Results: The search yielded 12,611 ITP, 19,276 SCS, and 15,184 PNS cases from 2010 to 2014. In this sample, the majority of procedures were performed at community hospitals, not university medical centers. The most common diagnosis cited for an ITP was an implant complication (n = 2,570), followed by spasticity, and non-malignant back pain. For SCS, the most common diagnoses were lower back pain (n = 5,515) or radiculopathy (n = 2,398). For PNS, by far the most common diagnosis related to urinary dysfunction (n = 8,745), with painful bladder syndrome a small minority (n = 133). General anesthetics were more often performed for ITP than for SCS and PNS procedures (60.6% vs. 31.8% and 32.2%, respectively). Hemodynamic instability was a common outcome (13.9% for ITP procedures); other common outcomes for all the procedures included case delays, inadequate pain control, and extended PACU stays.
Limitations: Despite the large sample size in this study, not all medical centers transmit their outcome data to NACOR. Furthermore, some institutions do not report clinical outcomes for every case to NACOR, making the sample size of assessing complications smaller and potentially more biased. Finally, procedures identified in the NACOR database using CPT may be similar but not identical and therefore potentially influence outcomes.
Conclusions: Databases such as NACOR can provide rich information on ITP, SCS, and PNS for physicians performing these procedures. In this sample, ITP procedures, performed on the patients with the most severe cormobidities and often-requiring general anesthesia, were the most likely to be associated with hemodynamic instability, inadequate pain control, and extended PACU stays. Complications relating to the ITP are also the most common reason for an operation. These findings underscore the importance of proper patient selection for ITP and other implantable pain devices, in particular for patients with malignant pain or multiple co-morbidities. To identify the root causes of complications, additional information is needed on the procedure performed (e.g., an implant vs a revision), the surgical technique used, and the device implanted, as well as on specific patient comorbidities. Such information will likely become more available as resources like NACOR expand and as electronic medical record systems and coding become more integrated.