Mistakes in ... 2021 - 15

ueg education
Mistakes in... 2021
caution. These features might obscure the
presence of pancreatic tumour and diminish the
accuracy of pancreatic sampling (54% and 74%
versus 89% and 91% in the presence versus the
absence of chronic pancreatitis, respectively),25,26
even in the case of small pancreatic lesions
<1 cm in diameter (80% versus 98%).27
These
lesions are difficult to see especially when
lobularity is present without honey-combing.27
Contrast highlights an adenocarcinoma
as a hypoenhanced lesion caused by important
fibrosis and the upward dilated ducts are more
clearly visualised.28
CH-EUS can guide EUS
Figure 4 | A patient with a past history of renal cancer. A pancreatic tail lesion missed by a radial scope and
detected with linear one.
gastrojejunal anastomosis with Billroth II and
Roux-en-Y reconstructions, EUS-FNA/FNB is
performed via the jejunal limbs using a linear
echoendoscope by gradual insertions followed
by scanning under fluoroscopy. In case of total
gastrectomy with Roux-en-Y reconstruction and
jejunal interposition it is more difficult to reach the
lesions in the head of the pancreas.20,21
The risk of
perforation is 1-6% and placing a guidewire or a
catheter using a balloon-assisted enteroscope may
increase safety.20
The use of a forward-viewing
echoendoscope is effective for evaluating the
periampullary area in 75% of patients with an
existing Billroth II reconstruction, but not in
those with a Roux-en-Y anastomosis.22
Passing the echoendoscope through a
malignant oesophageal stenosis (15-42% of
cases) may be difficult and increase the risk of
perforation.23
FNB in patient management, a fully expanded
Author, year and
reference number
Bekkali (2019)31
Number of patients
with stents
141 SEMS
149 PS
341 no stent
Antonini (2017)30
Kim (2015)32
56 PS
74 no stent
65 PS
11 SEMS
105 no stent
Siddiqui (2012)33
Ranney (2012)34
577 PS
100 SEMS
105 PS
45 SEMS
64 no stent
Fisher (2011)35
98 PS
72 no stent
FNA
FNA
100
90
64
88
89
92
No
FNA
100
100 vs 99
-
covered stent allows guidewire-assisted passage
of the echoendoscope (to avoid accidentally
impinging of the stent) under fluoroscopic control.
A duodenal stenosis caused by an ulcer, scarring
or by external compression related to a pancreatic
head tumour impedes the passage of the
echoendoscope at the closest point to access
the tumour by EUS-FNA/FNB.24
Using the long
position of the echoendoscope in the duodenal
bulb or sampling from the stomach should be
performed, but placing too much pressure on the
duodenal wall must be avoided because of the risk
of mechanical injury and perforation.
Mistake 4 Not tailoring the approach of EUS
tissue acquisition within the target lesion
Regardless of the use of EUS-FNA/
A negative result after sampling a solid lesion
that's surrounded by parenchyma with features
of chronic pancreatitis should be treated with
sampling within a lesion by avoiding the necrotic
areas, although for adenocarcinoma in a normal
pancreas it did not increase the accuracy of
sampling.29
Performing tissue acquisition,
preferably with FNB needles for procuring core
biopsy samples, eventually under CH-EUS
guidance and even repeating the procedure,
establishes the correct diagnosis.
The presence of a metallic biliary stent placed
for biliary obstruction may affect the EUS result
due to acoustic shadowing. This impedes
correct visualization of the tumour behind the
stent and the diagnostic yield is lower (Table 1).30-35
Torqueing or changing to the long position of
the echoendoscope provides a better window
for passing the needle; some authors even
recommend stent removal before tissue
acquisition. When a plastic stent is placed, the
orientation of the needle inside the lesion should
avoid the stent to stay away from further
dysfunctionalities, but the accuracy of tissue
sampling is not influenced.30
The orientation of the needle inside the
lesion should be established using the fanning
technique. However, the presence of necrosis
inside a mass impedes diagnosis and the needle
should avoid this part of the lesion.36
In such
EUS needle ROSE (%) Diagnostic accuracy rate of TA (%)
Stent
FNB
FNB
FNA or FNB
16
23
45
81 PS
79 SEMS
89
77
86
89
No stent
84
Influence of stents on TA
diagnostic rate
Yes
Odds ratio = 1.96 for SEMS
No
Yes
No difference PS-SEMS
No
-
Table 1 | Influence of biliary stents on EUS-guided tissue acquisition yield. FNA, fine-needle aspiration; FNB, fine-needle biopsy; PS, Plastic stent; SEMS, self-expandable
metal stent; TA, Tissue acquisition.
3
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