# Successful Multimodality Endoscopic Treatment of Gastric Outlet Obstruction Caused by an Impacted Gallstone (Bouveret's Syndrome)

Authors: Jason N. Rogart; Melissa Perkal; Anil Nagar
Journal: Diagnostic and Therapeutic Endoscopy
 (2008)

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## Abstract

Bouveret's syndrome is a rare condition of gastric outlet obstruction resulting from the migration of a gallstone through a choledochoduodenal fistula.  Due to the large size of these stones and the difficult location in which they become impacted, endoscopic treatment is unsuccessful and most patients require surgery. We report the case of an elderly male who presented with nausea and hematemesis, and was found on CT scan and endoscopy to have an obstructing gallstone in his duodenal bulb.  After several endoscopic sessions and the use of multiple instruments including a Holmium: YAG laser and electrohydraulic lithotripter, fragmentation and endoscopic removal of the stone were successful.  We believe this to be the first case of Bouveret's syndrome successfully treated by endoscopy alone in the United States. We describe the difficulties encountered which necessitated varied and innovative therapeutic techniques.


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## Body

## 1. Introduction

Gastric  outlet obstruction by a
gallstone migrating through a cholecystoduodenal
fistula (Bouveret’s syndrome) is a very rare condition, accounting for fewer
than 5% of cases of gallstone ileus [1].
Patients are often elderly with underlying comorbidities, which poses
significant challenges to both surgeons and endoscopists.  Though there have been several cases of
Bouveret’s syndrome reported in the literature, there are only a few descriptions
of successful treatment with endoscopy alone.
We report an unusual case of a large obstructing gallstone trapped in
the duodenal bulb and we discuss our successful endoscopic management using multiple
therapeutic modalities.


## 2. Case Report

An 85-year-old male with advanced
Alzheimer’s dementia, diabetes mellitus, and atrial fibrillation presented with
several days of nausea, vomiting, and lethargy. There was no report of
abdominal pain, fever, or chills.  His
vital signs were stable and his abdominal exam benign.  Nasogastric lavage was significant for one liter
of coffee-ground material.  His laboratory
examination demonstrated a white blood cell
count of 25 000/cm2, Hematocrit of 33%, creatinine of 1.5 mg/dL, and normal liver enzymes.  A CT scan (see
Figure 1) showed a markedly distended stomach, air in the biliary tree, and a thickened
gallbladder containing one or  two  large gallstones,  the largest 3×2.5 cm in
size, which appeared to be abutting the duodenal wall in an area of significant
inflammation.Computed tomography (CT) scan of abdomen and pelvis. (a) Axial image showing pneumobilia (arrow) and a dilated fluid-filled stomach (*). (b) 1-2 large gallstones (arrow) can be seen within an area of inflammation
where the gallbladder is in close proximity to the duodenum. (c) Coronal reconstruction showing gallstone within duodenum (long arrow), Pneumobilia (short arrows), and dilated stomach (*) are also seen.
(a)(b)(c)Endoscopy demonstrated old blood in
a distended stomach, and a large gallstone in the duodenal bulb obstructing the
pylorus (see Figure2(a)).  Due to the
patient’s advanced age and significant comorbidities, the patient’s surgeon
advocated endoscopic treatment.  The
position of the gallstone, the surrounding ulcerated mucosa, and the size of
the fistula’s orifice made attempts to  extraction
difficult despite the use of grasping forceps, jumbo biopsy forceps, different-sized and shaped snares, retrieval baskets and nets, as well as biliary
balloons and controlled radial expansion (CRE) balloons  (see Figure 2(b)).  There was no room to maneuver a mechanical
lithotripter around the stone, so a Holmium: YAG laser lithotripter was used (Boston
Scientific Microvasive, Natick, Mass, USA).
A 365-micron laser fiber was passed down one channel of a
double-therapeutic gastroscope (GIF 2T160, Olympus America, Inc., Pa, USA), and constant sterile water irrigation was infused
through the second channel.  Using a
total of 3840 joules, 3917 pulses per second for a total time of 7 minutes and
27 seconds, the laser successfully produced
small cracks in the stone and ultimately fragmented the proximal portion (see Figure 3(a)); however, the procedure was terminated due to rapid atrial fibrillation
and long procedure time.(a) large gallstone in the duodenal bulb, obstructing the pylorus. (b) Attempts to extract the stone failed with multiple instruments, including biliary and CRE balloons (*). The orifice of the choledochoduodenal fistula (arrow) can be seen.
(a)(b)Two different lithotripters were used to fragment the stone. (a) Holmium: YAG laser produced small cracks on the proximal surface (arrows) but the majority of the stone still remained impacted. (b) Electrohydraulic lithotripsy (IEHL) successfully shattered the outer “shell” of the stone (white arrow) and left behind a smaller, much harder core (black arrow). (c) Ultimately, the majority of the stone was fragmented after extensive use of both lithotriptors.
(a)(b)(c)Three days later endoscopy was
repeated, and an intracorporeal electrohydraulic lithotripter (IEHL; Northgate
Technologies, Ill, USA), which was previously unavailable, was employed, as
working with the Holmium: YAG laser had been only partially successful.  Using a 1.9F fiber (power of 1, increased to
40; frequency of 10, increased to 30) under constant saline irrigation, IEHL
was successful at shattering the outer “shell” of the stone and breaking it
into two large pieces, leaving behind an extremely hard, smaller core (see Figure3(b)).  Ultimately, the majority of the
stone was fragmented (Figure 3(c)) though the larger
piece still could not be removed easily from the duodenal bulb. Using a
“double-snare” technique, two jumbo polypectomy snares (3×6 cm, Cook Endoscopy,
Ind, USA) were used to grasp the still-impacted large stone fragment at
different angles and pull it into the stomach (see Figure 4).  Examination of the remainder of the duodenum
showed no other stones.  The large
cholecystoduodenal fistula was visualized, and the gastroscope easily passed
into the lumen of the gallbladder (see Figure 5).  Due to the length of the procedure, we chose
to complete the endoscopy another  day.Figure 4
Double-snare extraction technique.  Two overlapping jumbo polypectomy snares
(arrows) were used to grasp the stone at different angles, providing adequate leverage for extraction into the stomach.Visualization of the choledochoduodenal fistula. (a) After stone extraction, the large orifice
of the fistula (arrow) can be seen in the duodenal bulb, whose mucosa is diffusely ulcerated. (b) The gastroscope passed easily through the fistula into the lumen of the gallbladder.
(a)(b)On repeat endoscopy, the largest
stone fragment had again become impacted in the duodenal bulb, but was
extracted by placing a biliary balloon behind it and a polypectomy snare around
its center.  In the stomach, the largest
stones could not be crushed despite use of a mechanical lithotripter. To
further break up the stones, we used the Holmium: YAG laser (1000-micron fiber for 128 joules for 427 pulses
per second for a total delivery time of 2 minutes and 49 seconds) to bore multiple
holes into the center of each fragment, which was then crushed with a biliary stone
basket.  The larger fragments were
removed perorally (see Figure6) with a Roth net (US Endoscopy, Ohio, USA), while
the very small pieces were left behind to pass spontaneously.  Two weeks later, a fourth endoscopy was
performed to place a gastrostomy feeding tube, and no residual stones were seen
in the stomach or duodenum.  Additionally,
the orifice of the cholecystoduodenal fistula was significantly smaller.  Two months later, the patient remained asymptomatic.Figure 6
The largest stone fragments were removed perorally.  The inner composition of the largest piece
can be seen, measuring greater than 1 cm in diameter.


## 3. Discussion

Bouveret’s syndrome was first
described in 1896 by Leon Bouveret, a French internist and masterful
diagnostician, who reported two patients with large gallstones causing gastric
outlet obstruction, both of whom died [2].
This is a very rare condition, representing fewer than 5% of cases of
gallstone ileus, which itself complicates cholelithiasis in only 0.3–4% of
cases [1].  The condition has been
associated with significant mortality despite modern surgical techniques, and
is estimated to be 12–30% [3].  The first
case of successful endoscopic management of Bouveret’s was in 1985 [4]. Since
then there have been only a few other reports of endoscopic successes, some
requiring up to eight sessions [5–9] despite the use of multiple devices
including mechanical lithotriptors, electrohydraulic lithotripsy, and a variety
of laser lithotripters (e.g., Holmium: YAG, Rhoadmine 6G, FREDDY).  Even extracorporeal shock wave lithotripsy (ESWL),
another option for nonsurgical treatment, is rarely successful [10] and not
always readily available.  In a recent
review of the literature, Lowe et al. demonstrated that more than 90% of
patients ultimately require surgical management [1].Our case is representative of the
typical patient with Bouveret’s, as well as the difficult challenges involved
in approaching the endoscopic management.
Due to multiple comorbidities and a severely ulcerated duodenum, the
surgeons were hesitant to operate.  The
large size of the stone (more than 3 cm in diameter), its location, and the
propensity for instruments to follow the fistulous tract rather than the
duodenal lumen made maneuvering extremely difficult, and precluded the use of a
mechanical lithotripter.We chose the Holmium: YAG laser and IEHL
because of their prior successes in treating difficult common bile duct stones,
as well as their availability at our institution.  We found the Holmium: YAG laser to be useful
in producing initial cracks in the stone’s surface; IEHL, however, seemed to be
more effective in uniformly shattering the outer surface though not very
effective at attacking its harder, inner core.
Using both lithotripters required a significant amount of time, in part
because of the minimal working space as well as the extreme care involved in
avoiding further damage to the already ulcerated bulbar mucosa.  Using laser or IEHL fibers of larger diameter
may have improved the efficiency of lithotripsy, but these were not available
to us.  When approaching the large stone fragments
in the stomach, we found “drilling” multiple holes with the Holmium: YAG laser
to weaken the internal structure of the stone’s core to be a very useful
technique which then allowed us to easily crush these large fragments with a
basket.    We also found that to successfully extract
the stone from the bulb after lithotripsy, a single instrument did not provide
enough leverage or balance.   Using two
instruments with a double-channel gastroscope, however, was proved to be successful twice (once
using two snares, once using a snare and a biliary balloon).Another important observation in
our case was that between the second and third endoscopies, one of the stone fragments
left in the stomach again became impacted in the duodenal bulb.  Fortunately, this happened to be quite a
large fragment, for a smaller piece might have traversed the duodenum and
lodged in the ileum causing a distal gallstone ileus requiring surgery.  This complication has indeed been reported several
times in the literature [11, 12].  We
therefore recommend that caution be used when leaving stones in the stomach
between treatment sessions.  A
nasogastric tube was used to decrease the risk of vomiting and aspirating stone
fragments.  Finally, two weeks after
stone extraction, the size of the fistula was seen to be much smaller.  Surgical closure of the fistula is not
currently recommended; in fact in patients with Bouveret’s undergoing
enterolithotomy, the fistulas are left undisturbed and usually do not cause
complications [1].We believe our case to be the first
full-length report of the successful treatment in the United States of
Bouveret’s syndrome with endoscopy alone, as well as a unique description of
the complementary use of different lithotriptors and instruments.  Our experience suggests that endoscopists
faced with this clinical problem should use a double channel gastroscope,
initiate stone fragmentation with IEHL as first line management, crush stone
fragments that are left in the stomach to prevent ileal obstruction, and expect
multiple endoscopic sessions. We anticipate that due to the aging population in
the US
and the epidemic of obesity, Bouveret’s will likely become more common than
previously reported.  It is, therefore,
important for endoscopists to be familiar with the multiple options available
to effectively treat these difficult cases without surgery.



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