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Keywords
Celiac plexus block, Endoscopic Ultrasound
Introduction
Chronic abdominal pain can be a disabling
symptom in patients with pancreatic cancer and chronic pancreatitis.
When conservative therapy fails to adequately control the
patient's pain, celiac plexus neurolysis or block may provide
significant relief from pain. Celiac plexus block has traditionally
been performed percutaneously under radiologic guidance (1).
EUS provides an alternative method for performing celiac plexus
neurolysis. The celiac plexus is not visible by EUS. However,
the celiac ganglion is consistently located at the origin
of the celiac artery from the aorta. Since celiac artery is
well visualized during EUS, celiac plexus neurolysis can be
performed using a trans-gastric anterior approach.
Body
Efficacy and Patient Selection
The most appropriate candidates for EUS
guided celiac plexus neurolysis are patients with unresectable
pancreatic cancer with significant pain that are completely
or partially refractory to narcotic pain medications. EUS
guided celiac plexus neurolysis may provide effective palliation
of pancreatic cancer pain in 78-88% of patients (2, 3).
The efficacy of celiac plexus block in patients
with chronic pancreatitis is less well established and the
results are not as favorable in patients with pancreatic cancer.
There is some data suggesting that the efficacy of celiac
block under EUS guidance may be slightly better than CT guided
percutaneous block in patients with chronic pancreatitis (4).
Thus, celiac nerve block may be an option in selected cases
of chronic pancreatitis with disabling pain that is refractory
to narcotics and other medical measures. The decision to perform
EUS guided celiac nerve block in patients with chronic pancreatitis
should be made on a case-to-case basis with informed consent
explaining the risk of complications and somewhat limited
efficacy.
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Figure
1 |
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Figure
2A |
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Figure
2B |
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Figure
3A |
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Figure
3B |
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Figure
3C |
Equipment
1. Curved linear array echoendoscope ( GF-UC3OP
Olympus Corp, Melville, NY, FG 36UX Pentax Corp., Orangeburg,
NY).
2. Twenty two gauge EUS guided fine needle aspiration needle
(Wilson Cook, Winston-Salem NC; Olympus Corp, Melville, NY;
Mediglobe Corp, Temple, AZ.
3. 0.25% Bupivacaine for nerve block.
4. 98% dehydrated alcohol for injection or Triamcinolone acetonide
(40mg/ ml).
Technique
1. Patient fasting post midnight.
2. Informed consent.
3. Continuous normal saline infusion through an intravenous
line.
4. Conscious sedation with demerol and midazolam.
5. Per-oral insertion of a curved linear array echoendoscope.
6. The aorta is identified along its longitudinal axis while
imaging through the distal esophagus.
7. While maintaining the longitudinal view of the aorta on
the ultrasonic screen(Figure 1), the echoendoscope is gently
advanced towards the cardia/proximal stomach until the take
off of the celiac artery from the aorta is identified(Figure
2A, 2B).
8. The echoendoscope is slowly rotated clockwise or anti-clockwise
so that the celiac artery take-off is not visible. Color Doppler
is used to rule out major vessels between the transducer and
the peri-aortic space in this position.
9. A-22-gauge EUS guided FNA needle is connected to a 10cc
syringe (containing 5cc of normal saline) after removing the
stylet.
10. The needle with its outer sheath is loaded through the
biopsy channel of the echoendoscope and is slowly advanced
through the gastric wall into the peri-aortic space on the
side of the celiac artery(Figure 3A). An aspiration test is
preformed by gently pulling the plunger of the syringe. If
no blood return is seen in the syringe, the plunger is pushed
forward expelling a few cc of saline to clear the needle of
any tissue material.
11. The syringe with saline is disconnected and 3 cc's of
0.25% bupivacaine is injected slowly with a syringe(figure
3B). This is followed by injection of 10cc. of 98% dehydrated
alcohol for injection. In patients with chronic pancreatitis,
10cc of 0.25% bupivacaine mixed with 40mg of triaimcinolone
may be injected instead of the bupivacaine and alcohol combination
suggested above(Figure 3C).
12. The needle is then withdrawn from the peri-aortic space
into its outer sheath. The echoendoscope is then rotated to
the opposite side (clockwise or anti-clockwise) and similar
procedure is repeated as in step 11.
13. In selected cases when it is technically difficult to
find a good avascular window on either side of the celiac
artery, a single midline injection may be made in the peri-aortic
space at the angle between the take off of the celiac artery
and the aorta (Figure 2A).
14. The patient is then transported to the recovery room.
Post Procedure Recovery
1. Normal saline infusion is continued in
the recovery room.
2. The patient is observed for about 2 hours and monitored
especially for hypotension.
3. The patient is checked for the presence of orthostatic
hypotension prior to discharge.
Complications
A small percentage of patients undergoing
EUS guided celiac plenus neurolysis or block may experience
postural hypotension and diarrhea (2). These complications
are due to the sympathetic blockade and are usually self limited
and / or easily treatable by saline infusion (postural hypotension)
and anti-diarrheals. A single case of pseudoaneurysm of the
splenic artery after EUS guided celiac neurolysis using bupivacaine
and alcohol has been reported (5). There has also been a case
report of an intra-abdominal abscess occurring after EUS guided
celiac plexus block in a patient with chronic pancreatitis
using bupivacaine and steroids (5). This patient was on a
chronic proton pump inhibitors (PPIs), and the authors have
postulated that overgrowth of bacteria in the stomach due
to the PPI may have contributed to this complication. I prefer
to have patients stop their PPIs at least 5-7 days prior to
a planned EUS guided celiac neurolysis or block. In addition,
I give a single dose of IV antibiotic(usually of the quinolone
group) during or immediately after the procedure followed
by followed by the same antibiotic per orally for 5 days.
Some authors have suggested that antibiotics are not necessary
when bupivacaine and alcohol are used due to the bactericidal
properties of alcohol. The most dreaded complication of celiac
plexus neurolysis is paraplegia. This complication is seen
in about 1% of patients undergoing percutaneous radiology
guided celiac plexus neurolysis through a posterior approach
(1,6). Since EUS guided celiac plexus neurolysis is preformed
through an anterior approach with a short needle track it
has been theorized that the chances of paraplegia may be less
by using EUS as compared to a posterior percataneous approach(7).
Although no cases of paraplegia during celiac block have been
reported with the EUS approach, a theoretical risk of this
complication should still be kept in mind (and explained to
the patient during informed consent).
References
1. Lillemoe KD, Cameron JL, Kaufman HS,
et al Chemical Spanchnicectomy in patients with unresectable
pancreatic cancer: A prospective randomized trial
Ann Surg 1993: 217:447-457
2. Wiersema MJ, Wiersema LM Endosonography guided celiac
plexus neurolysis Gastrointest Endosco 1996;44:656-662
3. Gunartanam NT, Sarma AV, Norton ID, et al A prospective
study of EUS-guided celiac plexus neurolysis for pancreatic
cancer pain Gastrointest Endosc 2001;54:316-24
4. Gress F, Schmitt C, Sherman S, et al A prospective
randomized comparison of endoscopic ultrasound and computed
tomography guided celiac plexus block for the management of
chronic pancreatitis. Am J Gastroeneterol 1999;
94: 900-905
5. Gress F, Ciaccia D, Kiel J, Sherman S, et al. Endoscopic
ultrasound guided celiac plexus block for management
Gastroinestinal Endoscopy 1997;45:173(abstract)
6. Van Dongen RT, Crul BJP Paraplegia following celiac
plexus block Anesthesia 1991;46:862-863
7. Wiersema MJ Endosonography guided celiac plexus neurolysis
In: Bhutani MS (ed). Interventional Endoscopic Ultrasonography,
Harwood Academic Publishers, Amstedam, 1999;p117-123
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