The safest procedure to obtain cerebrospinal fluid (CSF) is lumbar puncture. However, there are situations where lumbar puncture is either contraindicated or technically not feasible. This includes infections in the lumbar area, obesity, previous spinal surgery, previous spinal fusion, a history of arachnoiditis, and the previous injection of chemotherapeutics. The usual and safe alternative method is a lateral cervical puncture under such circumstances.
Cisternal puncture describes the suboccipital access to cisterna magna, a CSF-containing space. It is a less frequently used procedure due to the high incidence of complications. As a result, cisternal puncture should be performed by a Neurological Surgeon for patients whose CSF cannot be accessed by lumbar puncture or lateral cervical puncture.1 It will be described in this chapter for the sake of completeness.
Dr. Mullan introduced a method for performing a percutaneous cordotomy using a lateral cervical puncture in the early 1960s.2 He introduced a strontium-90 needle through the C1-C2 interspace and into the subarachnoid space under fluoroscopic guidance. He then directed the needle anteriorly toward the anterior dura mater to interrupt the spinal thalamic fibers in an attempt to control intractable pain. The lateral cervical puncture is a direct derivative of this technique.
ANATOMY AND PATHOPHYSIOLOGY
Lateral cervical puncture involves the placement of a spinal needle into the C1-C2 interspace, posterior and inferior to the vertebral artery. The vertebral artery ascends through the foramina in the transverse processes of the cervical vertebrae beginning at the sixth cervical vertebra. It winds behind the lateral mass of the atlas (C1) to enter the skull through the foramen magnum (Figure 145-1). Inserting the needle 1 cm inferior to the tip of the mastoid process and 1 cm posterior from that point will avoid puncturing the vertebral artery (Figure 145-2).
The course of the vertebral artery at the level of C1-C2. A. Posterior view. B. Lateral view.
Anatomic landmarks for the lateral cervical puncture. The site for insertion of the needle is represented by an ⊗.
The spinal canal is formed by sequential vertebral foramina and is triangular in shape. Its lateral width is greater than the anteroposterior width. The spinal canal is more spacious in the upper cervical spine, allowing for safe placement of a needle into the C1-C2 interspace. The sagittal diameter of the spinal canal is approximately 23 mm at C1 and 20 mm at C2. The cross-sectional area of the cervical spinal canal is greatest at C2 and progressively decreases. It is smallest at the level of C7. The vertebral canal is narrower in women than in men. The spinal canal at the level of C1-C2 can be divided into three parts. ...