2. Coeliac Plexus

Question 1

The coeliac plexus

Answer 1

The coeliac plexus is the largest sympathetic plexus and lies anterior to the abdominal
aorta where, as a dense network of nerve fibres,

it surrounds the root of the coeliac artery at the level of L1.

It is a bilateral structure. There are two ganglia, right and left, which are closely
related to the crura of the diaphragm

The plexus receives the greater splanchnic nerve (fibres from T5 to T9 or 10)
and the lesser splanchnic nerve (fibres from T9/10 or T10/11).

Question 2

Relations

Answer 2

Superiorly lie the crura of the diaphragm;

posteriorly is the abdominal aorta;

laterally are the adrenal glands in the superior poles of kidneys

anterior relation is the pancreas

Question 3

Plexus block

Dx

Answer 3

Diagnostic: coeliac plexus block using local anaesthetic alone can be used for
diagnostic purposes, and for attempting to break a sympathetically mediated acute
pain cycle.

Question 4

Plexus block

Answer 4

Therapeutic: the plexus can be blocked in conjunction with intercostal nerves to
provide analgesia for intra-abdominal surgery.

This technique does not have many enthusiasts.

More commonly it is used for the relief of malignant visceral pain,
typically that due to carcinoma of the pancreas.

Neurolytic blocks give good analgesia
in up to 90% of patients, although the effect may only last for a number of months

Question 5

Non malignant pain

Answer 5

Non-malignant pain: the commonest such condition is chronic pancreatitis. Many
clinicians are reluctant to use coeliac plexus block in such patients both because of
the risks of paraplegia (1–2 per 1,000 owing to acute ischaemia at the watershed area
of the cord) and because its effective duration is limited.

Question 6

Technique of Coeliac Plexus Block

Answer 6

The patient lies prone. The procedure should be done under X-ray control.

The spinous process of T12 forms the apex of a flattened triangle whose base is a line
joining the twelfth ribs, and which ends 7–8 cm from the midline.

A 10–15 cm 20G needle (
Directed towards 1st lumbar vertebrae

Encounters body - redirected walked off anterolateral side of vertebrae + further advanced 2cm

The diffuse nature of the para-aortic plexus means that 20–25 ml of local anaesthetic
will be required on each side. Neurolytic agents should be injected only under X-ray
control, after needle placement has been confirmed by contrast media.

All neurolytic drugs lead to indiscriminate neural destruction. Alcohol (50–100%) is
usually preferred to phenol (5–8%) for coeliac plexus block. It can be very painful on
injection, but does not cause the vascular injury that is associated with phenol

The duration of effective action may be limited to 1–6 months. The neuritis that
can accompany the regeneration of nerves may be as severe as the original
symptoms

Question 7

Complications

Answer 7

: these include hypotension (it is a sympathetic block);

anterior spinal artery syndrome
(see under ‘The Blood Suppply to the Spinal Cord’); subarachnoid,

epidural and intrapsoas injection;

intravascular injection
(the aorta is very accessible on the left, the inferior vena cava is less vulnerable on the right);

retroperitoneal haemorrhage;

and visceral puncture.

The kidney is the organ that is most vulnerable.

The neurolytic agent may also spread unpredictably,
causing paresis, paralysis and dysaesthesia.