Thermal Radiofrequency Ablation of the Articular Branch of the Lateral Pectoral Nerve: A Case Report and Novel Technique.

The lateral pectoral nerve (LPN) innervates anterior shoulder structures. We report a novel technique for radiofrequency ablation (RFA) of the articular branch of the LPN (abLPN) to treat persistent anterior shoulder pain. Ultrasound and fluoroscopy were used to identify bony and vascular landmarks to target the midlateral and superior-lateral coracoid process (CP). Multiple thermal RFA lesions were delivered along this location without complication using a 20-gauge cannula. As a result, the patient has continued substantial relief of resting and dynamic deep anterior shoulder pain beyond 3 months. Ablation of the abLPN may provide anterior shoulder analgesia without causing motor weakness.

Cadaveric Study of the Articular Branches of the Shoulder Joint.

BACKGROUND AND OBJECTIVES: This cadaveric study investigated the anatomic relationships of the articular branches of the suprascapular (SN), axillary (AN), and lateral pectoral nerves (LPN), which are potential targets for shoulder analgesia. METHODS: Sixteen embalmed cadavers and 1 unembalmed cadaver, including 33 shoulders total, were dissected. Following dissections, fluoroscopic images were taken to propose an anatomical landmark to be used in shoulder articular branch blockade. RESULTS: Thirty-three shoulders from 17 total cadavers were studied. In a series of 16 shoulders, 16 (100%) of 16 had an intact SN branch innervating the posterior head of the humerus and shoulder capsule. Suprascapular sensory branches coursed laterally from the spinoglenoid notch then toward the glenohumeral joint capsule posteriorly. Axillary nerve articular branches innervated the posterolateral head of the humerus and shoulder capsule in the same 16 (100%) of 16 shoulders. The AN gave branches ascending circumferentially from the quadrangular space to the posterolateral humerus, deep to the deltoid, and inserting at the inferior portion of the posterior joint capsule. In 4 previously dissected and 17 distinct shoulders, intact LPNs could be identified in 14 (67%) of 21 specimens. Of these, 12 (86%) of 14 had articular branches innervating the anterior shoulder joint, and 14 (100%) of 14 LPN articular branches were adjacent to acromial branches of the thoracoacromial blood vessels over the superior aspect of the coracoid process. CONCLUSIONS: Articular branches from the SN, AN, and LPN were identified. Articular branches of the SN and AN insert into the capsule overlying the glenohumeral joint posteriorly. Articular branches of the LPN exist and innervate a portion of the anterior shoulder joint.

Digital Subtraction Angiography Use During Epidural Steroid Injections Does Not Reliably Distinguish Artery from Vein.

BACKGROUND: Epidural steroid injections (ESIs) are among the most common procedures performed in an interventional pain management practice. It is well known that tragic complications may arise from ESIs, most commonly those performed using a transforaminal approach. Digital subtraction angiography (DSA) has been hailed as a fluoroscopic technique that can be used to detect arterial placement of the injection needle, and therefore as a safety measure that can decrease the incidence of catastrophic sequelae of these procedures. OBJECTIVE: The objective of this article was to review existing scientific pain literature to determine if DSA can distinguish arterial vs. venous uptake. STUDY DESIGN: Narrative review. METHODS: The current narrative review of DSA in interventional spine was completed with a PUBMED search using the key words: digital subtraction angiography, epidural, fluoroscopy, intravascular injection, paraplegia, and quadriplegia in accordance with Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) guidelines. RESULTS: After identification of duplicate articles, 383 articles were screened by title, abstract, and/or full article review. Ten of these articles were deemed appropriate, after applying inclusion and exclusion criteria, as they specifically looked at the use of digital subtraction angiography in interventional spine epidural injections. This included 4 case reports, 3 prospective studies, one retrospective analysis, one prospective cohort study, and one meta-analysis. All of the available studies claiming that DSA was capable of detecting vascular spread are likely accurate, but no significant detection of specifically arterial spread has been reported. The known catastrophic complications related to ESIs are purported to be due to arterial injection of insoluble steroids or local anesthetic and detection of arterial spread of contrast during fluoroscopy would be of obvious benefit to the interventionalist. LIMITATIONS: Small study size, non-randomized studies between DSA and real time fluoroscopy. CONCLUSION: Existing studies do not support that DSA can predict arterial spread. In fact, DSA exposes the practitioner and the patient to higher levels of radiation without objective evidence of any safety parameters. KEY WORDS: Digital subtraction angiography, real-time fluoroscopy, transforaminal epidural injection, particulate steroids, cervical radicular artery, lumbar radicular artery, spinal cord injury.