Patient Selection

Most celiac plexus blocks are carried out for cancer pain therapy, and the majority of blocks used for cancer pain are related to gastric or pancreatic malignancies. The celiac plexus provides innervation to most of the gut from the lower esophagus to the level of the splenic flexure of the colon. Therefore, celiac plexus block may be applicable to a wide variety of patients with intra-abdominal malignancy.

Pharmacologic Choice

The celiac plexus is primarily a sympathetic ganglion; thus, low concentrations of local anesthetics are successful in blocking the celiac plexus. For example, 0.5% lidocaine, 0.125% or 0.25% bupivacaine, or 0.1% or 0.2% ropivacaine is adequate. If celiac plexus neurolysis is sought, my choice is 50% alcohol, which is formulated by combining equal volumes of 100% alcohol with 0.25% bupivacaine or 0.2% ropivacaine, to a total of 50 mL.

Anatomy

The celiac plexus has also been called the solar plexus, the celiac ganglion, and the splanchnic plexus (Fig. 47-1). It is the largest of the three great plexuses of the sympathetic nervous system in the chest and abdomen: the cardiac plexus innervates the thoracic structures, the celiac plexus innervates the abdominal organs, and the hypogastric plexus supplies the pelvic organs. All three of these plexuses contain visceral afferent and efferent fibers. In addition, they contain some parasympathetic fibers that pass through after originating in cranial or sacral areas of the parasympathetic nervous system.

Figure 47-1. Celiac plexus block: anatomy.

The celiac plexus innervates most of the abdominal viscera, including the stomach, liver, biliary tract, pancreas, spleen, kidneys, adrenals, omentum, small bowel, and large bowel to the level of the splenic flexure. The celiac plexus receives its primary innervation from the greater, lesser, and least splanchnic nerves, which arise from T5 through T12. The splanchnic nerves innervate the celiac plexus after traversing the posterior mediastinum and entering the abdomen through the crura of the diaphragm, a variable distance above L1 (Figs. 47-2 and 47-3). The splanchnic nerves are preganglionic, and after they synapse in the celiac ganglion proper (or associated ganglia), their postganglionic fibers radiate to the abdominal viscera (Fig. 47-4). Autopsy examination has shown that the number of ganglia making up the celiac plexus ranges from one to five, with the size of ganglia ranging from 0.5 to 4.5 cm in diameter.

Figure 47-2. Celiac plexus block: cross-sectional anatomy.

Figure 47-3. Celiac plexus block: parasagittal anatomy.

Figure 47-4. Celiac plexus block: functional anatomy.