Introduction
Gastric outlet obstruction (GOO) can occur from malignant and benign etiologies. Prior
to the identification of H. Pylori and the advent of proton pump inhibitors, peptic
ulcer disease (PUD) was the most common cause of GOO [1]
[2]. Since then, however, malignant disease has become the leading etiology of GOO [3]
[4]. Nevertheless, GOO from benign etiologies remains an important and difficult to
treat pathology that can occur secondary to different disease processes including
PUD, acute and chronic pancreatitis, caustic injury from substance ingestion, NSAID-induced
stricture, and Crohn’s disease [1]
[5]. In terms of management, endoscopic balloon dilation (EBD) has largely replaced
surgery as the first line treatment [1]. Although, clinical success is high with EBD in peptic strictures, it frequently
requires multiple endoscopy sessions with repeat dilations, a risk of perforation
in 3 – 7 %, and limited long-term response of 70 – 80 % [1]
[6]
[7]
[8]
[9]
[10]. In addition, EBD may be less successful in other diseases such as caustic injury
[11]
[12] and strictures secondary to pancreatitis due to more severe and extensive fibrostenotic
changes [5]. Other treatment modalities such as enteral stenting are associated with limited
data to support its regular use while surgery is invasive and associated with significant
risk for surgical morbidity [1]
[13]
[14]
[15]
[16].
Endoscopic ultrasound guided gastroenterostomy (EUS-GE) with a lumen apposing metal
stent (LAMS) is a novel technique described in the management of GOO [17]
[18]. It entails the insertion of the LAMS from the stomach to the small bowel distal
to the obstruction, thereby effectively bypassing the luminal compromise[19]. Small retrospective and prospective series have shown promising results with high
clinical success, safety, and low risk for stent obstruction [20]
[21]
[22]. However, the majority of the data on EUS-GE have involved patients with malignant
GOO and its efficacy in benign disease is largely undefined. The primary aim of this
international multicenter retrospective series is to ascertain the role of EUS-GE
in benign GOO by looking at technical feasibility, clinical success, and safety.
Patients and methods
This is a retrospective multicenter study involving 5 centers (3 North America, 1
Europe, and 1 Asia). The institutional review board at each participating center approved
this study. All consecutive patients who underwent EUS-GE for benign GOO between January
2014 and October 2016 were included. Patients were identified using center-specific
endoscopic or billing databases. Patients with malignant GOO were excluded. Several
patients in this study were individually reported in other separate publications but
those were not focused on benign disease [18]
[23]. Using electronic medical records, the following data were recorded: patient demographics,
etiology of GOO, anatomic site of obstruction (categorized as prepyloric/pyloric,
duodenal bulb, second part of duodenum, and descending duodenum), prior endoscopic
stenting and/or dilation, total procedure time, type/size/number of stent(s) used,
technical success, reasons for technical failure, EUS-GE technical approach, location
of needle puncture, whether the LAMS was dilated post insertion and caliber of dilation,
procedure related adverse events (AEs) with severity graded per the American Society
of Gastrointestinal Endoscopy (ASGE) lexicon [24], time to oral intake, type of diet tolerated after EUS-GE, post-procedure length
of hospital stay, need for re-intervention, and total duration of follow-up.
Study endpoints
The primary endpoint was the rate of clinical success defined as ability to tolerate
oral intake without vomiting. Diet tolerated was graded as 0 = no oral diet, 1 = liquids
only, 2 = soft solids, 3 = almost complete diet, 4 = full diet [25]. Secondary endpoints include procedure time, rate of technical success defined as
adequate positioning and deployment of the stent as determined endoscopically and
radiographically, and rate of AEs with the severity graded per the ASGE Lexicon [24].
EUS-GE techniques
All patients received intravenous antibiotics immediately prior to the procedure.
EUS-GE was performed in an endoscopy unit or in an operating room with general anesthesia
and endotracheal intubation. Informed consent was obtained from all patients prior
to the procedure. All EUS-GE were performed using therapeutic echoendoscopes by expert endoscopists
at tertiary care centers with or without trainee involvement. Decision regarding whether
or not subsequent stent removal was performed and timing of stent removal were at
the discretion of the endoscopist based on patients’ clinical evolution. 1 of the
following technical approaches was used (decision regarding the approach used was
at the discretion of the endoscopist):
Direct gastroenterostomy
DGE entails direct puncture of a small bowel loop adjacent to the gastric wall using
a therapeutic echoendoscope ( [Fig. 1]). To facilitate the puncture, a forward-viewing gastroscope (GIF-Q180 or GIF-Q190,
Olympus Corporation, Tokyo, Japan) is first inserted and fluid infused into the small
bowel distal to the obstruction. Generally, a total of 500 ml of fluid using a combination
of saline, methylene blue, and contrast is infused. A 19-gauge needle can then be
used as a “finder” needle to locate a small bowel loop closest to the stomach with
aspiration of blue-tinged fluid confirming the correct puncture site. The puncture
position may then be confirmed via enterogram. The needle is withdrawn while keeping
the endoscope in a stable position. A cautery-assisted LAMS (Axios stent, Boston Scientific
Corporation Inc., Marlborough, MA, USA) is then inserted directly across the stomach
and into the small bowel followed by stent deployment forming the gastroenterostomy.
Fig. 1 Direct EUS-guided gastroenterostomy. a Using a forward-viewing gastroscope, the small bowel is filled with saline mixed
with methylene blue and contrast. b Transgastric puncture of the small bowel with a 19-gauge needle. c Aspiration of blue-tinged fluid confirming the proper location of the puncture. d LAMS insertion with cautery assistance and stent deployment as seen on EUS. e Dilation of the stent with a 15-mm radial expansion balloon. f Endoscopic view of the gastroenterostomy stent post dilation.
Balloon assisted gastroenterostomy
The balloon assisted gastroenterostomy (BAGE) method has been developed with the hope
of improving small bowel access and possibly facilitating stent insertion with the
help of a guidewire. A stone retrieval or dilating balloon is inserted over a wire
across the obstruction. Following inflation of the balloon with contrast fluid, EUS-guided
puncture of the balloon is performed transgastrically with a 19-gauge needle. A guidewire
is then advanced deep into the small bowel to guide subsequent insertion of a LAMS.
EUS-guided double-balloon-occluded gastrojejunostomy bypass
Recently, a specialized double-balloon enteric tube (Tokyo Medical University Type;
Create Medic, Yokohama, Japan) has been introduced to facilitate EUS-GE [21]
[26] but is not yet available outside Japan. The balloon delivery catheter is inserted
over a wire across the obstruction. Water with contrast is then used to inflate both
balloons to anchor and seal the small bowel at 2 ends. Saline is then infused generously
between the 2 balloons. This water insufflation allows for approximation of small
bowel loop to the gastric wall leading to easier and safer transgastric EUS puncture
and stent insertion with the cautery tip assisted LAMS.
Statistical analysis
Continuous variables were reported as means with standard deviations (SD) or, for
skewed data, medians with interquartile ranges (IQR). Comparison of linear variables
was performed with the t-test and categorical variables by using the chi-square test.
A level of significance of P < 0.05 was adopted for all inferential testing. Statistical analysis was performed
by using SPSS version 16 (SPSS Inc, Chicago, Ill).
Results
A total of 26 patients (46.2 % female; mean age 57.7 ± 13.9 years) underwent EUS-GE
for benign GOO due to strictures from chronic pancreatitis (n = 11, 42.3 %), surgical
anastomosis (n = 6, 23.1 %), peptic ulcer disease (n = 5, 19.2 %), acute pancreatitis
(n = 1, 3.8 %), superior mesentery artery syndrome due to severe anorexia from colorectal
cancer (n = 1, 3.8 %), caustic injury (n = 1, 3.8 %), and duodenal wall hematoma from
blunt abdominal wall injury (n = 1, 3.8 %)([Table 1]). In the 6 patients with surgical anastomosis the type of surgery and site of obstruction
were: Billroth I for gastric cancer with stenosis at the gastoduodenal anastomosis
n = 1, duodenal repair post ERCP perforation complicated by duodenal stricture n = 1,
roux-en-y reconstruction with stricture at the gastrojejunostomy n = 2, proximal jejunal
resection for neuroendocrine tumor complicated by proxima jejunal stricture n = 1,
and undefined n = 1. Patients presented with predominant symptoms of nausea and vomiting
or abdominal pain in 21 and 5 cases, respectively. The decision to proceed to EUS-GE
in patients with conditions such as SMA syndrome, hematoma compression, and acute
pancreatitis was due to failure of conservative approach with a feeding tube, severity
of patients’ symptoms and predicted likelihood of prolonged obstruction. The site
of GOO was prepyloric/pyloric in 10 (38.5 %) patients, duodenal bulb in 4 (15.4 %),
second part of duodenum in 7 (26.9 %), and descending duodenum in 5 (19.2 %). A total
of 11 (42.3 %) patients had previous endoscopic therapy including 10 patients who
underwent endoscopic balloon dilation (EBD), 3 patients who underwent both EBD and
enteral stenting (ES), and 1 patient who underwent ES only. EUS-GE was performed as
a first line treatment in 15 (56.7 %) of the patients. Reasons for proceeding directly
to EUS-GE include high-grade obstruction with inability to traverse the obstruction
with a guidewire to allow for EBD (n = 1) and GOO secondary to etiologies that are
unlikely to respond to EBD (n = 12) or at risk of perforation due to ulceration (n = 2)
near the stricture. The mean number of prior dilation sessions per patient was 2.2 ± 1.1
with a mean maximal dilation diameter of 18.5 ± 2.2 mm. In the 4 patients with previous
enteral stenting, stent failure was due to stent migration (n = 1, esophageal partially
covered stent Niti-STM, Taewoong Medical co, South Korea) and stent obstruction (n = 3: LAMS n = 1, esophageal
partially covered stent Niti-STM n = 2).
Table 1
Baseline characteristics of patients undergoing EUS-GE for benign GOO[1].
|
Mean Age ± SD, years
|
57.7 ± 13.9
|
|
Female n (%)
|
12 (46.2)
|
|
Etiology n (%)
|
|
|
11 (42.3)
|
|
|
6 (23.1)
|
|
|
5 (19.2)
|
|
Acute pancreatitis
|
1 (3.8)
|
|
Superior mesenteric syndrome
|
1 (3.8)
|
|
Caustic stricture
|
1 (3.8)
|
|
External compression from a hematoma
|
1 (3.8)
|
|
Location of the obstruction n = (%)
|
|
|
10 (38.5)
|
|
|
4 (15.4)
|
|
|
7 (26.9)
|
|
|
5 (19.2)
|
|
History of prior enteral stent n = (%)
|
4 (15.4)
|
|
Mean number of previous enteral stents per patient
|
2.3 ± 1.3
|
|
Reason for enteral stent failure
|
|
|
3 (75)
|
|
|
1 (25)
|
|
History of prior dilation
|
10 (38.5)
|
|
Mean number of previous dilations ± SD
|
2.2 ± 1.1
|
|
Mean maximum dilation diameter (mm) ± SD
|
18.5 ± 2.2
|
1 Total number of patients = 26; SD, standard deviation
All EUS-GE procedures were performed with a 15-mm LAMS (cautery-assisted n = 24, non-cautery-assisted
n = 2) with the direct approach (n = 15, 57.7 %), balloon-assisted technique (n = 7,
26.9 %), or the EPASS technique (n = 4, 15.4 %) ( [Table 2]). Technical success was achieved in 25/26 (96.2 %) cases and dilation of the LAMS
performed in 13/25 (52 %) with a mean max diameter of 14.6 ± 1.0 mm. The mean procedure
time was 44.6 ± 26.1 minutes.
Table 2
EUS-GE procedure characteristics[1].
|
Type of Procedure
|
|
|
15 (57.7 %)
|
|
|
4 (15.4 %)
|
|
|
7 (26.9 %)
|
|
Procedure time in minutes
|
44.6 ± 26.1
|
|
Part of small bowel punctured
|
|
|
5 (19.2 %)
|
|
|
20 (76.9 %)
|
|
|
1 (3.8 %)
|
|
Type of Stent Used
|
|
|
24 (92.3 %)
|
|
|
2 (7.7 %)
|
|
Dilation of LAMS (n = 25)
|
13 (52 %)
|
|
Mean maximum dilation diameter (mm) ± SD
|
14.6 ± 1.0
|
1 Total number of patients = 26; EUS-GE, endoscopic ultrasound-guided gastroenterostomy;
LAMS, lumen apposing metal stents; EPASS, EUS-guided double-balloon-occluded gastroenterostomy
bypass
Clinical success was observed in 21/25 (84.0 %) cases with a median follow-up duration
of 176.5 (IQR: 47 – 445.75) days. Of those with clinical success, 66.7 % (14/21) were
able to tolerate a full diet, 14.2 % (3/21) an almost a complete diet, 4.8 % (1/21)
a soft diet, and 14.2 % (3/21) a liquid diet. The mean time to per oral intake was
1.4 ± 1.9 days. Clinical failure occurred in 4 patients: 2 patients required the insertion
of a percutaneous enteric gastrostomy with jejunostomy tube extension (PEG-J) for
suspected gastroparesis, 1 patient had PEG insertion for decompression of ileus, and
1 patient was managed surgically. The latter had failed to respond clinically to the
stent and following elective removal of the LAMS at 88 days post EUS-GE was discovered
to have gastric leak. The patient underwent emergency laparoscopic gastric wedge resection
and Billroth II reconstruction. The patient recovered uneventfully from the surgery
and had resolution of the gastric outlet obstruction following resection of the obstructed
pylorus secondary to a peptic stricture. The etiology of GOO in patients with clinical
failures included peptic stricture (n = 2), chronic pancreatitis (n = 1), and superior
mesenteric artery (SMA) syndrome (n = 1) ([Fig. 2]). In terms of safety, there were 2 procedure related AEs, which were rated as mild
in severity. These AEs were due to misdeployment of the LAMS with the distal end failing
to anchor in the small bowel. Both cases were managed with insertion of a fully covered
esophageal stent 18 × 60 mm (Niti-STM, Taewoong Medical co, Korea) through the LAMS to serve as a bridge during the index
procedure. No further sequelae were seen in these 2 patients. As aforementioned, there
was also a case of gastric leak needing surgical intervention following stent removal.
This complication was rated as a severe AE.
Fig. 2 Clinical outcomes and etiology of gastric outlet obstruction
In terms of reintervention, of the 21 patients with initial clinical success, unplanned
reintervention was performed in only 1 (4.8 %) patient due to stent obstruction secondary
to food impaction. This was successfully managed with endoscopic stent cleaning. Overall,
2 patients underwent elective LAMS stent removal with 1 patient due to inadequate
clinical response and the other following resolution of GOO due to a large hematoma
that subsequently resolved. As aforementioned, the stent removal for the former was
complicated by a gastric leak requiring surgery while the latter was uneventful with
no observed AE.
Discussion
EUS-GE is a novel and promising modality in the management of GOO. It offers the potential
benefits of a surgical bypass while maintaining a minimally invasive approach. Data
supporting the use of EUS-GE, however, have largely focused on malignant GOO [20]
[21]
[22]. To our knowledge, this present study is the first published data aiming at ascertaining
the role of EUS-GE in benign GOO. Overall, the rates of both technical and clinical
success were 96.2 % and 84.0 % respectively, with3 adverse events noted.
Benign GOO can arise from several etiologies with differing pathophysiology and response
to treatment. Endoscopic balloon dilation (EBD) has largely replaced surgery as the
initial treatment modality [1]. Clinical success with EBD, however, has been variable in the literature for benign
disease. GOO secondary to PUD appears to have the highest response rate to EBD. In
fact, 70 – 80 % of patients can achieve long-term symptomatic relief with the combination
of H. pylori eradication and EBD [1]
[5]
[6]
[7]
[8]
[9]
[10]. However, limited non-surgical options are available in patients who fail EBD. In
addition, EBD appears to be have limited effectiveness in other pathologies of benign
GOO. In caustic injury induced GOO, for example, EBD requires more endoscopic sessions
(range 2 – 13) and appears to be less effective in achieving long-term symptomatic
relief [11]
[12]. Strictures associated with chronic pancreatitis can also be especially difficult
to treat. In a series of 4 patients treated with EBD for chronic pancreatitis, all
4 patients failed to achieve symptomatic relief and underwent surgical intervention
[27]. Poor response to EBD in pancreatitis was also noted in another small series where
50 % of patients needed surgical intervention [28]. Extensive fibrosis and inflammation is believed to be the reason for the refractoriness
to dilation. In addition, although generally safe, EBD has been associated with a
perforation rate of 3 – 7 % [1]
[7]
[10]. Enteral stenting has also been explored in the management of benign GOO. Although
small series have shown promising results, stent migration occurs in up to 60 % of
the cases with fully covered metal stents, while uncovered metal stents are generally
prohibited due to risk of permanent stent anchoring [13]
[14]
[15]
[16].
EUS-GE may be a promising modality in benign GOO especially in patients who have failed
EBD, those with GOO etiologies that are unlikely to respond to dilation therapy, or
when dilation is technically not possible, such as when the obstruction is not traversable
with a guidewire. In our series, 84.0 % of the patients achieved clinical success
with EUS-GE with 42.3 % of the patients having failed previous EBD and/or ES. Clinical
success remained promising at 80.0 % in patients with technically successful EUS-GE
and failure with previous EBD and/or ES. The rate of unplanned re-intervention following
initial clinical success was also low at 4.7 %. This is in contrast to EBD, which
often requires several endoscopic sessions to achieve the appropriate luminal diameter
especially in non-peptic ulcer induced strictures [1]
[6]
[7]
[8]
[9]
[10]. In addition, the clinical success of EUS-GE is unlikely to vary according to the
etiology given that it is bypassing the anatomic site of obstruction instead of restoring
luminal patency through the stricture. In terms of safety, there were 2 mild AEs due
to stent misdeployment managed successfully with insertion of a bridging fully covered
metal esophageal stents. In addition, there was 1 severe AE following elective stent
removal resulting in a gastric leak needing emergency surgical management. To our
knowledge, this is first reported case of gastric leak post stent removal for EUS-GE
and there are currently no data in the literature looking at the safety of gastroenterostomy
stent removal. Although EUS-GE is promising, it is important to keep in mind that
it is still a developing technique in the management of benign GOO. The long-term
effects of an indwelling LAMS and the safety of its removal are still to be further
elucidated, while the technique remains to be perfected. Until further data is available,
EUS-GE in benign GOO is best reserved for patients who have failed EBD or if EBD is
not possible. It may also be considered in GOO etiologies that tend to have a poor
response to dilation, such as strictures secondary to pancreatitis or caustic injury.
Our study is limited by its retrospective design. Consecutive patients were used to
limit selection bias and although it is the largest and only series focused on benign
GOO, it remains a small study involving 26 patients. Also, follow-up time of 176.5
(IQR: 47 – 445.75) days is relatively short and longer follow-up data will be needed
to ascertain the long-term clinical effectiveness and safety of EUS-GE. In addition,
all procedures were performed by expert endoscopists at tertiary centers; therefore,
our results may not be generalizable to community hospitals. As with any developing,
novel technique, EUS-GE should be performed by experienced endoscopists at centers
with the appropriate surgical and interventional radiology backup.
Conclusion
In conclusion, EUS-GE is a promising modality for the management benign GOO caused
by a variety of etiologies and may be especially useful in those who fail to respond
to endoscopic balloon dilation. Questions regarding the safety of long-term stent
indwelling and subsequent stent removal, however, remain to be elucidated. Larger
studies and prospective data are needed to further validate this novel endoscopic
technique in treating benign GOO.
Chen YI, James TW, Agarwal A et al. EUS-guided gastroenterostomy in management of
benign gastric outlet obstruction Endoscopy International Open 2018; 06: E363–E368. DOI: 10.1055/s-0043-123468
In the above mentioned article was middle name of an author missing. Correct is: Theodore
W. James
