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Complications of Cervical Discography

Wenxi (Richard) Gao MD, MA and Srdjan S. Nedeljković MD

Brigham & Women’s Hospital, Boston, MA, USA

Introduction

Neck pain remains a widespread issue among the general population and can often be disabling, with an annual incidence as high as 14.6% [1]. There are multiple possible sources of axial neck pain including muscles, ligaments, facet joints, and intervertebral discs. Initial evaluation should include a thorough history and physical exam and may include imaging such as X-ray, magnetic resonance imaging (MRI), and computerized tomography (CT) scans. Although MRI can accurately visualize anatomic changes, the abnormalities may not be the source of neck pain [2]. Also, imaging alone cannot reliably differentiate between symptomatic and asymptomatic degenerative discs. Cervical discography is a procedure that aims to identify painful discs from non-painful discs in order to confirm the diagnosis of “discogenic pain”. Smith and Cloward initially described cervical discography independently in the 1950s [3, 4]. Discography entails injecting a contrast agent into the nucleus pulposus of cervical intervertebral discs to identify painful discs as well as morphologic derangements [5]. A positive result involves reproducing pain symptoms with disc injection. The use of cervical discography has decreased due to improved quality of imaging techniques, concerns about lack of validity and procedural risks of complications, namely discitis, which will be discussed in this chapter.

Anatomy

Each of the seven cervical vertebrae (C2–3 through C7–T1) has intervertebral discs between the vertebral bodies. The cervical intervertebral discs are innervated by sensory (80%) and autonomic (20%) neurons [6]. Each disc is composed of fibrocartilaginous material that comprises the annulus fibrosis, with the nucleus pulposus in the center (Figure 21.1). The cervical nucleus pulposus is relatively smaller than its counterpart in the lumbar spine and, as a result, accommodates less contrast during discography. Cadaveric studies have shown that most cervical discs accept less than 0.5 ml, while degenerated discs may allow for an injection of 0.5–1.5 ml [7]. The cervical intervertebral discs are surrounded by critical structures including the airway, esophagus, major vessels, and neural structures that are important to avoid while performing cervical discography (Figure 21.2).

**Figure 21.1** Intervertebral disc [8].

Indications

To diagnose discogenic pain and document disc morphology
Pre-operative planning process to decide whether to operate on symptomatically painful discs and exclude asymptomatic ones
Cervical discography is generally not an initial diagnostic test for neck pain and should be performed after standard workup does not clearly identify a cause.

Contraindications

Symptoms of cervical myelopathy or cord compression
Coagulopathy
Allergy to contrast or dye
Infection (local or systemic)
Lack of patient consent.

Technique

Prior to patient positioning, intravenous (IV) access is obtained and pre-procedural antibiotics are administered. The patient is placed supine on the procedure table with the neck slightly hyperextended and support placed under the shoulders. The neck is then widely disinfected and draped. A C-arm fluoroscopy machine is placed to obtain a posteroanterior (PA) view of the target cervical discs, with care taken to align the vertebral end plates.

A right-sided approach is recommended in order to avoid potential puncture of the esophagus. The right carotid artery is manually displaced laterally and the skin is then anesthetized with local along the intended trajectory (Figure 21.3). Ultrasound (US) guidance may be used to better identify the vasculature (Figure 21.4). Under fluoroscopic guidance, in an ipsilateral oblique view, a 22–25 G needle is advanced into the center of the target disc, with confirmation in both the PA and lateral view. The disc may be injected individually, or additional needles may be inserted until there are needles in place for all cervical discs intended for injection. Once the needles are in position, between 0.25–0.5 ml of contrast is injected into the nucleus pulposus. In a normal disc, no pain will be elicited. In an abnormal disc, there may be extravasation of the contrast or pain may be elicited (Figure 21.5). A positive result occurs when the elicited pain is similar to the patient’s typical neck pain in both location and intensity, and especially when radicular pain is reproduced. Injection volume, disc appearance, pain scores, and pain locations should be noted for each level.