Lumbar sympathectomy. Stellate ganglion blockade. Coeliac plexus block. Splanchnic nerve block, страница 4

Entry of the needle tip into a large vessel, the peritoneal cavity or a viscus should all be diagnosed before injection if the procedure is done with radiological control.

1. Hypotension is sometimes seen, particularly orthostatic hypotension. This may last up to 3 days and should be treated with bed rest and avoidance of sudden changes to the upright posture.

2. Backache may be due to local trauma, irritation of alcohol in the psoas muscle or the involvement of the lumbar plexus.

3. Retroperitoneal haemorrhage.

Figs. 211:2.

Needlepoints 1-2 cm in front of LI and within the shadow of the lateral wall of the vertebral body. Courtesy of Dr. G.RM. Carmichael.

Fig. 211:1.

Splanchnic nerve block

Because all the sympathetic sensory nerves from the abdominal viscera are located within the splanchnic nerves, it is possible to achieve the same analgesic results by blocking the splanchnic nerves as would be obtained with a coeliac plexus block. The parasympathetic nerves and many of the afferent sympathetic pathways involving the coeliac plexus remain undisturbed.

Anatomy

There are three splanchnic nerves, the greater, the lesser and the lowest. The greater splanchnic nerve is derived from sympathetic (afferent and efferent) fibres arising in or passing through-the 5th to the 9th thoracic ganglia of the sympathetic chain. It runs over the bodies of the thoracic vertebra, becoming more anterior as it descends. It enters the abdomen by piercing the crus of the diaphragm and ends in the coeliac plexus. The lesser splanchnic nerve is from fibres arising in or passing through the 10th and llth thoracic ganglia, and the lowest splanchnic nerve from the 12th ganglia. All three nerves are in close relationship with each other as they enter the abdomen on the anterior and superior aspect of the 12th thoracic vertebra (Fig. 213:1 and 2).

Indications

1. Pain of acute or chronic pancreatitis

2. Visceral pain due to cancer

Patient position

Prone with a pillow under the abdomen.

Landmarks

1. Twelfth rib

2. Midline

Needle insertion

A wheal is raised 8-10 cm lateral to the midline just below the 12th rib. The needle is inserted cephalad and medially so as to contact the body of the 12th thoracic vertebra (Fig. 213:4). Using radiological control the needle is redirected and advanced until it is over the upper and anterior quadrant of the body of the 12th vertebra in the lateral view and within the lateral boundaries of the vertebral body in the anteroposterior view (Fig. 213:3).

Drugs and dose

A preliminary injection of 1-2 ml of radio-opaque dye is made to exclude an intravascular position of the needle. If the dye stays in close relationship to the vertebral body, then 10 ml of 6-10% phenol with added dye may be injected.

If a local anaesthetic is to be used (e.g. in acute pancreatitis) then 10-15 ml of l°7o lidocaine or 0.25% bupivacaine or their equivalent should be used and a catheter similar to that used for continuous epidural block can be inserted for repeated injections.

A bilateral injection may be necessary, but substantial pain relief can occur with a unilateral block. If a bilateral block is done then care must be taken in interpreting the lateral view of the radiological picture, and it is helpful to screen continuously during the injection.

Complications

Orthostatic hypotension.

Fig. 213:1.

1. Greater splanchnic nerve

2. Lesser splanchnic nerve

3. Least splanchnic nerve

4. Coeliac ganglion and plexus

5. Left branch of hepatic artery

6. Right branch of hepatic artery

7. Cystic artery

8. Common hepatic artery and hepatic plexus

9. Right gastric artery

10. Gastroduodenal artery

11. Superior pancreaticoduodenal artery

12. Right gastroepiploic artery

13. Superior mesenteric ganglion, artery and plexus

14. Aorticorenal ganglion and renal artery with plexus

15. Ovarian/testicular artery and plexus

16. Phrenic plexus and inferior phrenic artery

17. Left gastric artery and plexus

18. Splenic artery and plexus

19. Pancreatic branch

20. Gastric arteries

21. Splenic branch