Image Guidance Technologies for Interventional Pain Procedures: Ultrasound, Fluoroscopy, and CT

Chronic pain is a common medical condition. Patients who suffer uncontrolled chronic pain may require interventions including spinal injections and various nerve blocks. Interventional procedures have evolved and improved over time since epidural injection was first introduced for low back pain and sciatica in 1901. One of the major contributors in the improvement of these interventions is the advancement of imaging guidance technologies. The utilization of image guidance has dramatically improved the accuracy and safety of these interventions. The first image guidance technology adopted by pain specialists was fluoroscopy. This was followed by CT and ultrasound. Fluoroscopy can be used to visualize bony structures of the spine. It is still the most commonly used guidance technology in spinal injections. In the recent years, ultrasound guidance has been increasingly adopted by interventionists to perform various injections. Because its ability to visualize soft tissue, vessels, and nerves, this guidance technology appears to be a better option than fluoroscopy for interventions including SGB and celiac plexus blocks, when visualization of the vessels may prevent intravascular injection. The current evidence indicates the efficacies of these interventions are similar between ultrasound guidance and fluoroscopy guidance for SGB and celiac plexus blocks. For facet injections and interlaminar epidural steroid injections, it is important to visualize bony structures in order to perform these procedures accurately and safely. It is worth noting that facet joint injections can be done under ultrasound guidance with equivalent efficacy to fluoroscopic guidance. However, obese patients may present challenge for ultrasound guidance due to its poor visualization of deep anatomical structures. Regarding transforaminal epidural steroid injections, there are limited evidence to support that ultrasound guidance technology has equivalent efficacy and less complications comparing to fluoroscopy. However, further studies are required to prove the efficacy of ultrasound-guided transforaminal epidural injections. SI joint is unique due to its multiplanar orientation, irregular joint gap, partial ankylosis, and thick dorsal and interosseous ligament. Therefore, it can be difficult to access the joint space with fluoroscopic guidance and ultrasound guidance. CT scan, with its cross-sectional images, can identify posterior joint gap, is most likely the best guidance technology for this intervention. Intercostal nerves lie in the subcostal grove close to the plural space. Significant risk of pneumothorax is associated with intercostal blocks. Ultrasound can provide visualization of ribs and pleura. Therefore, it may improve the accuracy of the injection and reduce the risk of pneumothorax. At present time, most pain specialists are familiar with fluoroscopic guidance techniques, and fluoroscopic machines are readily available in the pain clinics. In the contrast, CT guidance can only be performed in specially equipped facilities. Ultrasound machine is generally portable and inexpensive in comparison to CT scanner and fluoroscopic machine. As pain specialists continue to improve their patient care, ultrasound and CT guidance will undoubtedly be incorporated more into the pain management practice. This review is based on a paucity of clinical evidence to compare these guidance technologies; clearly, more clinical studies is needed to further elucidate the pro and cons of each guidance method for various pain management interventions.

Facet injection trends in the Medicare population and the impact of bundling codes

BACKGROUND CONTEXT

Interventional spine procedures have seen a steady increase in utilization over the last 10 to 20 years. In 2010, the Current Procedural Terminology (CPT) codes for facet injections were bundled with image guidance (fluoroscopic or computed tomography) and limited billing to a maximum of three levels. This was done in part because of increased utilization and to ensure that procedures were done appropriately with image guidance.

PURPOSE

The study aimed to evaluate if the CPT code changes correlated with a decreased utilization of facet injections.

STUDY DESIGN

This is a retrospective time series study.

PATIENT SAMPLE

The sample was composed of 100% Medicare Part B claims submitted for facet joint injections from 2000 to 2012, as documented in the Centers for Medicare & Medicaid Services (CMS) Physician Supplier Procedure Summary (PSPS) master files.

OUTCOME MEASURES

Procedure numbers and trends were the outcome measures.

METHODS

The trends of facet injections were analyzed from 2000 to 2012 using the CMS PSPS master files. The total number of lumbosacral and cervical-thoracic facet injections was noted. Changes over those years were calculated with specific attention to 2010, when CPT were bundled with image guidance and injections were limited to no more than three levels. Also, to account for the growth in the Medicare population, a calculation was done of injections per 100,000 Medicare enrollees. No funding was used for this study.

RESULTS

Facet injection utilization increased from 2000 to 2012, with an average growth rate of 11% per year for lumbosacral facet injections and 15% for cervical-thoracic facet injections (per 100,000 Medicare enrollees). The largest growth occurred from 2000 to 2006 (25% growth per year for lumbosacral and 32% for cervical-thoracic injections per 100,000 Medicare enrollees) and this leveled off from 2007 to 2012 (-3% growth per year for lumbosacral and -2% for cervical-thoracic injections per 100,000 Medicare enrollees). The biggest drop in these procedures was in 2010, when there was a drop of 14% for lumbosacral facet injections and 15% drop for cervical-thoracic facet injections (per 100,000 Medicare beneficiaries).

CONCLUSIONS

Facet injection utilization notably increased from 2000 to 2006 but began to level off from 2007 to 2012. The most notable drop was in 2010, which correlated with the release of new CPT codes that bundled image guidance and limited procedures to three levels or less.