Sympathetic Nerve Block and Neurolysis

Published on 10/03/2015 by admin

Filed under Neurosurgery

Last modified 10/03/2015

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Chapter 10 Sympathetic Nerve Block and Neurolysis

Sympathetic nerve block may relieve pain by several mechanisms. One possible mechanism is interruption of afferent nociceptive fibers that accompany the autonomic nerves. Another possible mode of action of sympathetic block involves disruption of reflex control systems, which causes alteration of peripheral or central sensory processing. Finally, the peripheral vasodilation caused by sympathetic block may relieve ischemic pain and facilitate the healing of painful skin ulcers.

Procedures

Stellate Ganglion

Unlike other types of neurolytic techniques, radiofrequency thermocoagulation (RFTC) does not tend to produce Horner’s syndrome (unilateral miosis ptosis, anhidrosis, and enophthalmos), and it can be performed simply with very little morbidity.

Technique

Stellate ganglion block

The simplest and most satisfactory approach is the anterior paratracheal approach, which is performed as follows:

We prefer thoracic sympathetic block to stellate ganglion block for block of the upper extremity sympathetic nerve.

Pulsed radiofrequency lesioning or radiofrequency thermocoagulation of the stellate ganglion

Some authors had introduced the technique of radiofrequency lesioning of the stellate ganglion under the guidance of fluoroscope. We do not agree with their techniques and do not perform the procedure under the guidance of fluoroscope. One author introduced the technique previously in his book. According to his technique the radiofrequency needle tip should rest at the junction of the transverse process and the vertebral body. Where is the stellate ganglion?

The stellate ganglion formed by the fusion of the inferior cervical and the first thoracic ganglion as they meet anterior to the vertebral levels of the C7 and T1 vertebra. The ganglion lies on the longus colli at the vertebral level covered by prevertebral fascia and is surrounded by important structures, such as common carotid artery, internal jugular vein, thyroid, vagus nerve, phrenic nerve, and brachial plexus. The distance from the junction of the transverse process and the vertebral body to the stellate ganglion may show individual differences according to the individual shape and volume of longus colli. We, therefore, cannot estimate where the ganglion is on the lateral image of C-arm. In addition, the location of the ganglion is also highly variable. We, also cannot estimate where the ganglion is on the AP image of C-arm. When we use the radiofrequency lesioning techniques (Fig. 8-16) we should remember how and where the lesion is made. If radiofrequency needle tip rests at the junction of the transverse process and the vertebral body, where the radiofrequency lesion is made? These are the reason why we do not perform the procedure under the guidance of fluoroscope.

Ultrasound-guided and CT-guided radiofrequency lesioning of the stellate ganglion can be alternative procedures. However, the identification of the ganglion or its chain at the vertebral levels on the ultrasound or CT images is also very difficult.

Thoracic Sympathetic Ganglion

Techniques

Thoracic sympathetic block

The following procedure is used for thoracic sympathetic block:

Splanchnic Nerve

Anatomy

As shown in Figure 10-6, the greater (T5 through T10), lesser (T10 and T11), and least (T11 and T12) splanchnic nerves cross the lateral side of the body of T12 as they sweep forward to penetrate the diaphragm and form the celiac plexus. The pleura are attached posteriorly to the vertebral bodies and create a well-defined compartment.

image

Figure 10–6 Position of the splanchnic nerves and celiac plexus. T10, tenth thoracic vertebra; L1 and L2, first and second lumbar vertebrae.

(Modified from Justins DM: Pain and autonomic nerve block. In Wildsmith JAW, Armitage EN, McClure JH [eds]: Principles and Practice of Regional Anaesthesia, 3rd ed. Edinburgh, Churchill Livingstone, 2002, pp 291-309.)