This document reviews interventional endoscopic ultrasound (EUS) procedures, including EUS-guided fine needle aspiration (FNA). EUS-FNA is a safe and accurate procedure used to diagnose lesions in the esophagus, pancreas, lymph nodes, liver, lungs and other organs. It has a diagnostic accuracy of 64-94% for pancreatic masses. EUS also guides drainage of pancreatic pseudocysts and bile ducts when conventional endoscopy fails. Emerging applications include EUS-guided celiac plexus neurolysis for pain relief, fiducial placement for tumor localization, and ablation techniques for treating pancreatic cysts and tumors. In summary, the document outlines the various diagnostic and therapeutic applications of

1. Interventional Endoscopic Ultrasound (EUS): Current
Status

2. Review Article
Endoscopic ultrasound combines the concept of
endoscopy and intraluminal ultrasonography. Interventional
EUS started off in 1992, when Vilmann, et al., reported the
first case of EUS guided FineNeedle Aspiration Cytology
(FNAC) of pancreatic mass with a linear array echo-
endoscope [1]. It has grown in scope gradually over the next
two decades. This article will review the indications, accu-
racy, complications and limitations of interventional EUS.
EUS GUIDED FNA
A fundamental principle of EUS-fineNeedle is that the
information obtained should have the potential to affect
patient management. In addition, the indications for EUS-
FNA should be guided by its diagnostic accuracy, cost
effectiveness, and patient comfort and safety. EUS guided
FNAis used for evaluation of esophageal cancer, pancreatic
mass, celiac lymphnode, submucosal lesion, lung cancer,
mediastinal mass, liver mass and left adrenal mass.
Diagnostic yield of EUS guided FNAis listed in Table 1.
In esophageal cancer,EUS FNA is useful in determining
therapy in whom distant metastasis has been excluded by
CECT.Two important factors determining respectability are
spread to adjacent organs (T4) and involvement of celiac
lymph node. The involvement of celiac lymph node in
esophageal cancer portends a bad prognosis with a 5 year
survival of less than 10%. EUS FNA is superior to multislice
CT scans in assessing celiac node involvement [2-5].
The sensitivity and specificity of malignant lymph
node involvement by EUS FNA is 83-90% and
93-100% respectively [5,6]. CT combined with EUS has
been shown to be cost effective staging evaluation for
esophageal cancer [7].
Early diagnosis and resection alone provides hope of
long term survival in pancreatic cancer. The overall
prognosis of pancreatic cancer is poor . EUS is more
289 Apollo Medicine, Vol. 7, No. 4, December 2010
INTERVENTIONAL ENDOSCOPIC ULTRASOUND (EUS): CURRENT STATUS
Piramanayagam P* and Palaniswamy KR**
*Junior Consultant, **Senior Consultant, Department of Gastroenterology, Apollo Hospitals, Greames Raod,
Chennai 600 006, India.
Correspondence to: Dr K R Palaniswamy, Senior Consultant, Department of Gastroenterology, Apollo Hospitals,
Greames Raod, Chennai 600 006, India.
Key words: EUS-FNA, Diagnostic accuracy, EUS-guided procedures, Tumour localisation, Tumour therapy.
sensitive in detecting pancreatic tumors less than 2 cm
than other imaging modalities [8]. In evaluating solid
pancreatic masses, the result of EUS-FNA is excellent,
with a sensitivity of 64-94.7% and specificity of 97-100%.
Routine pre-operative FNA may be valuable in establishing
alternate diagnosis like pancreatic lymphoma, tuberculosis,
autoimmune pan-creatitis which may also present as focal
pancreatic mass lesions. Some centres attempt at biopsy
only if the lesion is unresectable. EUS FNA has a lower risk
of peritoneal carcinomatosis than CT guided FNA [9].
Pancreatic cysts may be pseudocysts, cystic neoplasm
of pancreas or simple cysts of pancreas. The management
varies and correct diagnosis becomes imperative. EUS
provides detailed images of pancreas, septations, nodule,
surrounding pancreatic parenchyma, relation to pancreatic
duct, nearby vessels, bile duct. EUS FNA of cystic lesion
provides with fluid for cytology, tumor markers (CEA, CA
19-9) , amylase, lipase. Fluid CEA level of more than 192
Table 1. Diagnosticyieldof EUSguidedFNAC
Author (year) Sensitivity Specificity
(%) (%)
Pancreas mass
Dewitt, et al.(2003) [11] 82
Liver SOL
Eloubeidi, et al. (2003) [12] 94.7 100
Bhutani, et al. (1997) [13] 64 100
Mediastinal node
Wallace, et al. (2001) [14] 87 100
Annema, et al. (2003) [15] 75 100
Hilar stricture
Fritscher-Ravens, et al. [16] 89 100

3. Apollo Medicine, Vol. 7, No. 4, December 2010 290
Review Article
ng/mL had an accuracy of 79% in correctly identifying
cysts which require surgery [10].
Erickson, et al. reported that failure to have a
cytopathologist in attendance increases the number of
passes, reduces definitive cytological diagnoses, prolongs
procedure time, increases risk and consumes additional
needles. If a cytopathologist or a cytotechnician is not in
attendance, three passes should be taken through lymph
nodes and five to six passes through pancreatic masses to
ensure adequate cellularity in >90% of cases [17].
EUS FNA has an overall complication rate of <1%. The
complications include scope associated perforations,
hemorrhage following aspiration of pseudocyst,
bacteremia following aspiration of cystic lesion. The risk
of acute pancreatitis following EUS FNA of pancreatic
mass lesions is 0.64%. Thus, EUS FNA is a safe and well
tolerated procedure [18,19].
EUS GUIDED MANAGEMENT OF PSEUDOCYST
EUS enables assessment of pseudocyst wall thickness,
confirmation of size, delineates contents (clear fluid vs.
walled off pancreatic necrosis), checks distance from the
gastrointestinal (GI) lumen, evaluates for intervening
vasculature. Only 50% ofpancreatic fluid collections cause
luminal compression [20]. EUS guided pseudocyst drainage
has added advantage of not needing luminal compression as
needle could be guided under sonographic guidance. EUS
also has the added advantage of having Doppler which will
help avoid major vessels on the wall of pseudocyst thus
Fig 1. EUS guided FNAC of celiac lymph node. Fig 2. EUS guided aspiration of pancreatic fluid collection.
minimising risk of bleeding. It has been shown in
randomised trial that endoscopic drainage (12%) is
associated with more complications that EUS guided
drainage (0%). The technical success and complication rate
, reinterventions were not significantly different for EUS
guided pseudocyst drainage as compared to surgical
intervention with added benefit of less hospitalisation time
and improved QOL [22].
EUS GUIDED CELIAC PLEXUS BLOCK/
NEUROLYSIS
Celiac plexus is localised anterior to the celiac trunk take
off from aorta. EUS guided celiac plexus neurolysis
involves injection of bupivacaine (3-10 mL) followed by
dehydrated absolute alcohol (10 mL). It provides pain relief
in upto 80% in pancreatic cancer patients at 10 weeks.
Celiac plexus block involves use of triamcinolone (40 mg)
in place of alcohol [23,24]. It provides temporary relief in
patients with chronic pancreatitis. It has been reported to be
successful in 55-80% of patients with chronic pancreatitis
who report improvement in pain scores and reduction in
opioid medicine requirements.
Complications of celiac plexus block or neurolysis are
infrequent and mostly self-limited. The most common side-
effects are transient diarrhea and hypotension; these can be
seen in up to 38% and 44% of patients, respectively [25].
Sympathetic blockade can manifest as diarrhea and
hypotension due to a relative unopposed visceral
parasympathetic activity. In most patients, the diarrhea is
mild and self-limiting and lasts less than 48hrs [26].

4. Review Article
291 Apollo Medicine, Vol. 7, No. 4, December 2010
Medium term pain relief is reported to be upto 70% [39].
Technical failures may be due to acute angle at which linear
EUS accesses pancreatic duct, difficulty in trasmural
dilation due to dense fibrosis. Stent migration and block are
observed in 5-44% on medium term follow up [40-41].
TUMOR LOCALISATION
EUS guided gold fiducial placements have been used to
localise pancreatic tumors planned for stereotactic
radiotherapy [42]. Localising small neuroendocrine
tumours at surgery may become difficult. Preoperative
tattooing or fiducial placement by EUS has been shown to
reduce operative time.
TUMOR THERAPY
EUS guided ethanol ablation with or without addition of
antitumor agents of pancreatic cysts has been reported in
case series. EUS-guided injection has been reported in
pancreatic neuroendocrine tumors,adrenal metastases and
GIST. EUS guided radioactive iodine seed implantation has
been studied in animal models [43]. EUS guided
photodynamic therapy is another exciting development
whereby light source can be passed through a large bore
EUS needle. EUS guided radiofrequency ablation has been
studied in porcine models [44].
SUMMARY
EUS guided FNA, pseudocyst aspiration, celiac plexus
neurolysis are all common interventional EUS procedures
done worldwide. EUS guided bile duct drainage and
pancreatic duct drainage are options to be considered when
access to desired duct is not achieved. Exciting new
developments like EUS guided tumor localisation and
ablation techniques are in clinical studies and will become
available in future.
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EUS GUIDED BILE DUCT DRAINAGE
Malignant biliary obstruction is managed
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Fig 3. EUS guided FNAC of liver SOL

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