Utility of endoscopic ultrasonography in endoscopic drainage of pancreatic pseudocysts in selected patients.

Abstract

To determine the effect of endoscopic ultrasonography (EUS) on endoscopic drainage of pancreatic pseudocysts and to determine patency with fistula dilation and placement of multiple stents.
Between September 1995 and January 1999, 19 patients underwent endoscopic drainage of pancreatic pseudocysts, 17 of whom were assessed by EUS before drainage. Radial EUS scanning was used to detect an optimal site of apposition of pseudocyst and gut wall, free of intervening vessels. A fistula was created with a fistulatome, followed by balloon dilation of the fistula tract. Patency was maintained with multiple double pigtail stents. The primary goal of this retrospective study was to determine whether EUS affected the practice of endoscopic drainage of pancreatic pseudocysts.
In 3 patients, drainage was not attempted based on EUS findings. In the other 13 patients (14 pseudocysts), creation of a fistula was successful on 13 occasions, and no immediate complications occurred. However, 1 patient subsequently developed sepsis that required surgery. All other patients were treated with balloon dilation, multiple stents, and antibiotics, with no septic complications. Of 14 pseudocysts (in 13 patients), 13 (93%) resolved.
Results of EUS may alter management of patients considered for endoscopic drainage of pancreatic pseudocysts. Endoscopic ultrasonography was useful for selecting an optimal and safe drainage site. The combination of balloon dilation, multiple stents, and antibiotics appears to resolve pancreatic pseudocysts without septic complications.

Full text

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Endoscopic US and Drainage of PseudocystsMayo Clin Proc, August 2001, Vol 76
794
Mayo Clin Proc. 2001;76:794-798794
© 2001 Mayo Foundation for Medical Education and Research
Original Article
Utility of Endoscopic Ultrasonography in Endoscopic Drainage of
Pancreatic Pseudocysts in Selected Patients
IAN D. NORTON, MBBS, PHD; JONATHAN E. CLAIN, MD; MAURITS J. WIERSEMA, MD;
EUGENE P. DIMAGNO, MD; BRET T. PETERSEN, MD; AND CHRISTOPHER J. GOSTOUT, MD
From the Division of Gastroenterology and Hepatology and Internal
Medicine, Mayo Clinic, Rochester, Minn.
Dr Norton is supported by the American Society for Gastrointestinal
Endoscopy/Olympus Endoscopic Training Scholarship.
Presented in part at Digestive Disease Week, New Orleans, La, May
19, 1998.
Individual reprints of this article are not available. Address corre-
spondence to Christopher J. Gostout, MD, Division of Gastroenterol-
ogy and Hepatology, Mayo Clinic, 200 First St SW, Rochester, MN
55905 (e-mail: gostout.christopher@mayo.edu).
T
ries.1-11 However, the optimal strategy for endoscopic
cystogastrostomy and cystoduodenostomy has yet to be
determined.12 In particular, selection of the puncture site is
a critical factor. The optimal site is a point at which there is
close apposition between the pseudocyst and the gut with-
out intervening vessels. Free perforation and hemorrhage,
2 major associated complications,1,13,14 occur when the
drainage site does not meet these criteria. Of note, the
optimal site is not always the location of maximal bulging
of the enteric wall seen at endoscopy. However, attempting
drainage without seeing a luminal bulge increases risk14
and decreases likelihood of success.15 Endoscopic ultra-
sonography (EUS) may be useful for selecting the site of
maximal apposition and for revealing whether vessels in-
tervene between the gut and the pseudocyst. Additionally,
EUS may be useful for identifying features of the fluid
he safety and efficacy of endoscopic drainage of pan-
creatic pseudocysts have been shown in many se-
• Objectives: To determine the effect of endoscopic ul-
trasonography (EUS) on endoscopic drainage of pancre-
atic pseudocysts and to determine patency with fistula
dilation and placement of multiple stents.
• Patients and Methods: Between September 1995 and
January 1999, 19 patients underwent endoscopic drainage
of pancreatic pseudocysts, 17 of whom were assessed by
EUS before drainage. Radial EUS scanning was used to
detect an optimal site of apposition of pseudocyst and gut
wall, free of intervening vessels. A fistula was created with
a fistulatome, followed by balloon dilation of the fistula
tract. Patency was maintained with multiple double pigtail
stents. The primary goal of this retrospective study was to
determine whether EUS affected the practice of endo-
scopic drainage of pancreatic pseudocysts.
• Results: In 3 patients, drainage was not attempted
based on EUS findings. In the other 13 patients (14 pseudo-
cysts), creation of a fistula was successful on 13 occasions,
and no immediate complications occurred. However, 1 pa-
tient subsequently developed sepsis that required surgery. All
other patients were treated with balloon dilation, multiple
stents, and antibiotics, with no septic complications. Of 14
pseudocysts (in 13 patients), 13 (93%) resolved.
• Conclusions: Results of EUS may alter management of
patients considered for endoscopic drainage of pancreatic
pseudocysts. Endoscopic ultrasonography was useful for se-
lecting an optimal and safe drainage site. The combination of
balloon dilation, multiple stents, and antibiotics appears to
resolve pancreatic pseudocysts without septic complications.
Mayo Clin Proc. 2001;76:794-798
collection that may affect subsequent management, such as
the presence of considerable amounts of solid debris,
which would necessitate prolonged lavage of the cavity.16
The routine use of EUS in this setting has been addressed
specifically in only 1 study,17 and some investigators have
considered EUS unnecessary as a routine part of endo-
scopic drainage.13 The aim of this study was to determine
whether EUS affects the practice of endoscopic drainage of
pancreatic pseudocysts.
PATIENTS AND METHODS
Patients were identified from the endoscopic database at
our institution. Patients were included in this study if their
records were eligible for review under current state law (no
patients were excluded on this basis). Clinical and proce-
dural details were obtained from the hospital record and the
endoscopic database. Patient follow-up was performed by
using a scripted telephone interview and by reviewing the
records of subsequent clinic visits. The study was approved
by the Mayo Foundation Institutional Review Board.
Between September 1995 and January 1999, 19 patients
underwent endoscopic drainage of pancreatic pseudocysts,
17 of whom underwent EUS before drainage. These pa-
tients were referred from our pancreas clinic. During the
same period, other patients at our institution were referred
via surgical channels and underwent surgical cystoenter-
ostomy or cystogastrostomy. Patients were considered po-
tential candidates for the endoscopic approach if computed
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Mayo Clin Proc, August 2001, Vol 76Endoscopic US and Drainage of Pseudocysts 795
tomography revealed apposition between the pseudocyst
and the upper gut. All patients were symptomatic (we do
not attempt drainage of asymptomatic pseudocysts). All
patients were examined with a radial echoendoscope
(EUM20 or EUM30, Olympus, Melville, NY) at 7.5 MHz.
If the pseudocyst was suitable for attempted drainage, the
site of maximal apposition between gut and pseudocyst
(with no intervening vascular structures) was identified by
obtaining a mucosal biopsy specimen from that site. Ex-
ceptions to this approach were the 2 most recent procedures
in patients 12 and 13, which were performed with a curved
linear array echoendoscope (FG-36UX, Pentax, Orange-
burg, NY). With this instrument, drainage of the pseudo-
cyst was by direct real-time EUS guidance.
All patients underwent endoscopic retrograde cholan-
giopancreatography to exclude a proximal pancreatic stric-
ture. Radial EUS scanning detected an optimal site of
apposition of pseudocyst and gut wall, free of intervening
vascular structures (Figure 1). Cystogastrostomy or cysto-
enterostomy puncture was performed with use of a 0.038-
in wire fistulatome (Wilson-Cook, Winston-Salem, NC).
After the pseudocyst cavity was entered, the fistulatome wire
core was removed and replaced with a floppy-tip guidewire
under fluoroscopic control. In every patient except patient 1,
the fistula tract was pneumatically dilated, initially to 8 mm
by using biliary balloons (Maxforce, Microvasive, Boston,
Mass) (Figure 2, A); then through-the-scope balloons (Rigi-
flex, Microvasive) were used for dilation up to 18 mm
(Figure 2, B and C). The tract was then stented with multiple
double pigtail stents (7F-10F) (Figure 2, D). If pseudocyst
contents were purulent or EUS showed a considerable solid
component, nasocystic lavage was performed. Patients re-
ceived parenteral antibiotics during the procedure and oral
ciprofloxacin while stents were in place. Follow-up com-
puted tomography was performed monthly to monitor
pseudocyst resolution. Stents were removed endoscopically
when the pseudocyst had resolved. In patients 12 and 13 in
the series, pseudocyst puncture, wire exchange, and initial
(over-the-wire) balloon dilation were performed under real-
time EUS guidance with use of a curved linear array endo-
scope (Figure 3), as previously described.18 Of note, in one of
these patients, drainage had initially failed after an appropri-
ate puncture site was detected with use of a radial scanner.
RESULTS
Endoscopic ultrasonography was performed before at-
tempted drainage in 16 patients with 17 pseudocysts and in
1 patient with an organized pancreatic necrosis (11 men
and 6 women with a median age of 45 years; range, 34-75
years). The cause of the pseudocysts and pancreatic necro-
sis was chronic pancreatitis in 9 patients (53%) and acute
pancreatitis in 8 patients (47%). Pain was the presenting
Figure 1. Radial endoscopic ultrasound image shows apposition of
pseudocyst (PCYST) and gastric (GAST) wall. STOM = stomach.
symptom in all subjects. Median pseudocyst size was 8 cm
(range, 5-14 cm).
Three patients did not undergo endoscopic drainage
because of EUS findings. One patient had extensive gastric
collateral vessels, one lacked apposition between the gas-
tric wall and the pseudocyst (distance between structures, 2
cm), and one had spontaneous reduction in pseudocyst size.
Drainage was unsuccessful in 1 patient without a luminal
bulge even though there was good apposition between the
luminal wall and the pseudocyst by EUS imaging. There-
fore, drainage was successful in 13 patients (76% [13/17]
of patients based on intention to treat and 93% [13/14] of
patients in whom drainage was attempted). Of 17 patients
in whom a pseudocyst was present, a pronounced extra-
luminal bulge was apparent in 12 (71%).
Drainage was through the gastric wall in 11 patients
(79%) and through the duodenal bulb in 3 (21%). The
details of the procedures are summarized in Table 1. No
immediate complications occurred.
Follow-up is available in 10 patients, with a median
follow-up of 6 months (range, 2-24 months). Late complica-
tions occurred in 2 patients (14%). Patient 1 developed
sepsis 5 days after insertion of a single 7F stent. This patient
received no prophylactic antibiotics and did not undergo
tract dilation. Nasocystic lavage did not control symptoms,
and he subsequently underwent excision of the pseudocyst
and distal pancreatectomy. Subsequent patients received
prophylactic antibiotics (ciprofloxacin) and maintenance an-
tibiotics while stents were in place, had balloon dilation of
the tract, and had placement of larger stents (10F or 11.5F).
No further infectious complications occurred. Patient 11
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Endoscopic US and Drainage of PseudocystsMayo Clin Proc, August 2001, Vol 76
796
Figure 2. Steps of endoscopic fistula formation. A, Initial dilation via wire-guided balloon. B,
Final dilation with “through-the-scope” balloon. C, Fistula after dilation. D, Multiple stents are
inserted to maintain patency and allow drainage both through and around the stents.
experienced sharp epigastric pain 1 week after stent place-
ment that was relieved by eating. On endoscopy, one of the
stents was impacting into the opposite gastric wall; the stent
was replaced with a shorter stent, and no further complica-
tions occurred. Of 14 pseudocysts (in 13 patients), 13 (93%)
resolved. Of patients in whom follow-up was available, 3
had died; all deaths were unrelated to the pseudocyst. Three
patients have had recurrence of pseudocysts, one of whom
presented with pain and chose surgical cystoenterostomy. In
the other 2 patients, recurrences were asymptomatic.
After resolution of the pseudocyst and stent removal,
patient 11 had a symptomatic recurrence that required re-
peated endoscopic drainage. Nine months after the second
procedure and removal of stents, a 6-cm asymptomatic
pseudocyst was detected and managed conservatively. Pa-
tient 4 died of unrelated causes 11 months after drainage;
an asymptomatic 7-cm pseudocyst was found at postmor-
tem examination.
DISCUSSION
Throughout the past 10 years, endoscopic drainage of
pseudocysts has gained acceptance as a relatively nonin-
vasive and efficacious technique.1-8 However, many issues
regarding endoscopic drainage have yet to be resolved,
including the best route of drainage (into the gut vs through
the papilla) and the most efficient, most cost-effective, and
safest way to establish drainage into the gastrointestinal
tract.
Our data demonstrate that EUS is useful for assessing the
applicability of endoscopic drainage of pancreatic pseudo-
cysts. Results of EUS affected the management of 3 patients
(18%). These patients did not undergo endoscopic drainage
because of inadequate apposition with the gut wall in one,
presence of extensive extragastric collateral vessels in one,
and spontaneous reduction in size of pseudocyst in one. No
immediate complications occurred in the patients who un-
derwent drainage. Fockens et al17 reported that routine EUS
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Mayo Clin Proc, August 2001, Vol 76 Endoscopic US and Drainage of Pseudocysts797
Table 1. Details of 13 Patients Who Underwent Endoscopic Ultrasonography
Before Drainage of Pancreatic Pseudocysts
Size of
pseudocyst
(cm)
Maximal
balloon dilation
(mm) Patient Drainage siteStents
1
2
11
11
Gastric body
Gastric fundus
Not applicable
6
2 × 7F
Nasocystic for 5 d,
then 2 × 10F
Nasocystic for 5 d,
then 2 × 11.5F
2 × 11.5F
2 × 11.5F
2 × 11.5F
1 × 11.5F
10F and 11.5F
2 × 11.5F
3 × 11.5F
35 Duodenal bulb6
4
5
6
7
8
9
12 Gastric body
Gastric body
Gastric body
Gastric fundus
Gastric body
Gastric antrum
Duodenal bulb
12
11.5
14
8
12
7
6
5
7
Not stated
8
18
12 10
11
(first drainage)
11
(second drainage)
12*
13*†
10 Gastric body155 × 10F
8
7
Gastric body
Duodenal bulb
Gastric body
12 3 × 10F
2 × 7F
Nasocystic for 6
wk, then 2 × 10F
6
8 12
*Drainage under real-time ultrasonographic guidance.
†Patient with liquefied pancreatic necrosis.
before pseudocyst drainage altered subsequent patient man-
agement in 38% of patients primarily because of poor cyst-
gut apposition, small pseudocyst, extensive varices, and dis-
covery that the lesion was not a pseudocyst. In contrast to our
approach, they did not routinely use EUS to select an optimal
drainage site, and they did not perform drainage under direct
EUS guidance, as we did in 2 patients (14%).
Severe hemorrhage from the fistula site is relatively
common (5%-15%)5,7,19 and potentially fatal. Many pa-
Figure 3. Entry of a needle into a pseudocyst under real-time
ultrasonographic guidance with use of a curved linear array in-
strument in the stomach.
tients with pseudocysts have gastric varices or extensive
extragastric collateral vessels as a result of either cirrhosis
with portal hypertension or splenic vein thrombosis. These
vessels may not be obvious during mucosal inspection.
Endoscopic ultrasonography is ideal for identifying these
vessels. One of our patients had extensive extragastric
collaterals that precluded endoscopic drainage. No hemor-
rhagic complications occurred after EUS selection of the
fistula site. Endoscopic ultrasonography is useful for
avoiding puncture of a splenic artery pseudoaneurysm, a
potentially fatal error. This infrequent complication after
acute pancreatitis may simulate pseudocyst formation and
occurred in 9% of patients in 1 series.13
Endoscopic ultrasonography is useful for reevaluating a
pseudocyst immediately before drainage. In one of our
patients the pseudocyst spontaneously decreased in size
(since findings on computed tomography 1 week previ-
ously), and the patient was managed conservatively. Simi-
larly, Fockens et al17 reported that a pseudocyst was not
seen with EUS in 9% (3/32) of patients. Moreover, they
changed the diagnosis in 6% of patients from pseudocyst to
another (cystic) lesion based on EUS findings.
Additionally, EUS has been used to locate a site for
puncture when the initial attempts at endoscopic punc-
ture were unsuccessful.15 An ultrasound probe inserted
through a standard endoscope channel was used for this
purpose.20 Of note, a pronounced extraluminal bulge was
not apparent in 5 (29%) of 17 patients in our series,
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Endoscopic US and Drainage of PseudocystsMayo Clin Proc, August 2001, Vol 76
798
further suggesting a role for EUS in targeting the site of
maximal apposition.
It was not possible to drain the pseudocyst in one of our
patients even though EUS findings were interpreted as
demonstrating a suitable site. This patient had no endo-
luminal bulge at endoscopy and declined further attempts
at endoscopic therapy. Drainage under real-time ultrasono-
graphic control would have likely been successful in this
patient, as it was in patients 12 and 13.
Should EUS be used in all patients? Because EUS al-
tered the management in 3 of our patients and was useful in
preventing damage to intervening vessels, we advocate use
of EUS in all patients considered for endoscopic drainage,
rather than those selected as “technically difficult” cases.
However, of importance, EUS is a technique in evolution.
Several reports have described linear scanning EUS instru-
ments that allow the entire procedure to be performed
under real-time ultrasonographic control.21,22 This ap-
proach was used in patients 12 and 13 in our series. Newer
linear instruments with a therapeutic channel are available,
allowing 10F stents to be placed under real-time EUS
control. This approach may become the treatment of choice
for endoscopic drainage of pseudocysts.
An important feature of our procedure is balloon dilation of
the fistula tract. Cautery incision to enlarge the initial puncture
is thought to increase the risk of hemorrhage, which we be-
lieve may be reduced by using balloon dilation. Patient 1 had
stents placed without dilation of the fistula tract. The pseudo-
cyst became infected after early occlusion of the single stent,
and ultimately this patient required surgery. After this experi-
ence, all patients had balloon dilation and placement of mul-
tiple stents with no infectious complications. Even with bal-
loon dilation, the tract progressively closes over time (as
evidenced by appearance at the time of stent removal). How-
ever, multiple stents allow drainage around and between the
stents even if the stents occlude. This technique is analogous to
that described by Baron et al16 for drainage of liquefied pan-
creatic necrosis. One patient early in our series was treated in
this fashion for organized pancreatic necrosis, although the
role of endoscopic drainage of this entity remains controver-
sial. Furthermore, current practice of endoscopic drainage of
organized necrosis includes lavage of the cavity for a pro-
longed period via either nasocystic drainage or percutaneous
gastrostomy extension tube.16
CONCLUSION
Our study showed the utility of EUS before attempted
endoscopic drainage of pancreatic pseudocysts. Use of
EUS allows reassessment of the lesion before drainage and
selection of an optimal site for controlled puncture (apposi-
tion and absence of vascular structures). Balloon dilation of
the drainage site appears to be a safe technique. In addition
to balloon dilation, the placement of multiple stents and
routine use of prophylactic antibiotics appear to ensure
drainage with little risk of infection.
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