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exposure to radiotherapy. The technical and clinical successes of
stenting are lower when compared with primary colorectal tumors.
Proper patient and family counseling is key in setting a realistic
expectation and preparing the patient for the potential need for
surgical intervention in case of an immediate technical failure or
long-term clinical failure.
Benign Colonic Disease
Benign colonic strictures resulting in clinically significant obstruction can be caused by factors related to diverticulitis, inflammatory bowel disease, ischemia, radiation, postoperative anastomotic
strictures, or complex colorectal fistulas including colovesical and
colovaginal fistulas. Anastomotic strictures are known to be the
most common complication following colonic surgery, seen in up
to 30% of cases. The bulk of scientific literature on the management
of benign colonic strictures stems from Crohn’s disease strictures,
which are usually found at the ileocecal valve or at the surgical
anastomoses. The available data on management of strictures from
other etiologies, such as diverticular disease, colonic ischemia, and
radiation injury, are limited.
The morphology of benign strictures differs from malignant
ones in that they are associated with increased fibrosis and scarring;
thus, therapy is more challenging. Some of the endoscopic therapies
include endoscopic balloon dilation (EBD), intralesional steroid
injections, SEMS placement, endoscopic incisional therapies, and
more recently, placement of a lumen-apposing metal stent (LAMS).
Graded EBD is the recommended initial treatment for benign strictures and should be considered before alternative endoscopic or
surgical therapies. On one hand, balloon dilation has a high clinical
success exceeding 88% (Fig. 2), but on the other hand it has a high
recurrence rate of 30% to 88%, often requiring redilations. Strictures
remain refractory in >20% of cases and may eventually require
surgical revision. Patients with complex anastomoses or multiple
strictures are less likely to have favorable treatment outcomes compared with those with a short (<4 cm) focal stricture in a straight
colonic segment. In patients with Crohn’s disease, it is preferable to
avoid dilation in the setting of poor prognostic factors for response
to dilation, such as active inflammation, presence of large ulcers
within a stricture, or smoking. Intralesional steroid injection is a
known adjunct that can enhance the effectiveness of balloon dilation,
reducing the time to redilation, and should be considered, especially
in cases of acute inflammatory strictures.
On the basis of paucity of data and heterogeneous studies,
SEMS should not be used as first-line therapy for benign strictures.
Uncovered colonic SEMS are typically not removable and may predispose patients to long-term complications. The use of fully covered
self-expandable metal stents (FCSEMS) in benign colonic strictures
is not FDA approved; however, off-label use of FCSEMS could be
considered in refractory or recurrent benign colonic strictures. Some
of their drawbacks include patient intolerance, iatrogenic stricture
formation, and a high rate of early stent migration of up to 40%,
which may reduce long-term clinical success. Recently, endoscopic
suturing of FCSEMS to overcome migration has been used, but
A
C
FIG. 2 Endoscopic balloon therapy for benign strictures. (A) History of colonic diverticulitis status after sigmoid colectomy and colostomy followed by
takedown complicated by stricture at left-sided colorectal anastomosis with erythema and edema. (B) The stricture was approximately 3 mm in width
(compared with opened biopsy forceps). (C) A long 0.035-inch guidewire was passed across the stricture, and a through-the-scope dilating balloon was
used to dilate the stricture to 11 mm. (D) Water was infused, and the balloon was pulled close to the scope lens to enable visualization of the lumen of the
stricture during dilation. (From Copland AP, Wang AW. Clinical Gastrointestinal Endoscopy (3rd ed.). Chapter 40: Colonic Strictures.)
B
D
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FIG. 3 Lumen-apposing metal stent for benign colonic stricture from Crohn’s disease. (A) Crohn’s disease–related high-grade stricture. (B and C) Endoscopic view
of fully covered lumen-apposing, self-expanding metal stent (AXIOS; Boston Scientific). (D) Stricture following removal of lumen-apposing metal stent showing significant improvement. (From Clinical Gastroenterology and Hepatology Image of the Month: Treatment of Crohn’s Disease Anastomotic Stricture with a Lumen-Apposing Metal Stent.
Jordan E. Axelrad, Simon Lichtiger, Amrita Sethi. Published May 18, 2017. Figures A, B, and D: doi.org/10.1016/j.cgh.2017.05.016.)
this procedure is expensive and technically difficult and should be
performed by experienced endoscopists. Caruso etal. (2015) performed a retrospective analysis of 16 patients who had postsurgical
anastomotic colorectal strictures that were refractory to endoscopic
dilation and underwent stent therapy, and they reported a 100%
technical and early clinical success with median follow-up of 21
months. Prolonged clinical success was achieved in 9/16 (56%)
cases. There were no major complications, including perforation
and bleeding. Stent migration occurred in 3 (19%) cases, and a
larger median stent diameter was significantly associated with a
more successful clinical outcome (26 mm vs. 20 mm,P = 0.006).
In certain clinical situations, covered esophageal stents have also
been used in an off-label manner to treat benign colonic strictures.
Unfortunately, most covered esophageal stents come on a stiff
introducer (ranging from 16Fr to 24Fr in size) and within short
catheters and must be passed over a guidewire, not through the
scope channel (TTS), thus limiting their use to left-sided colonic
strictures. However, one commercially available covered esophageal stent in the United States made by Taewoong Medical (Niti-S
Esophageal TTS, Gyeonggi-do, South Korea) comes on a 10.5Fr
flexible catheter that can be deployed through the channel of a
therapeutic gastroscope, which might enable successful covered
metal stenting of difficult to reach or angulated colonic strictures.
Endoscopic incisional therapies using a sphincterotome or a
needle-knife to perform strictureplasty allows for controlled radial
mucosal incisions along the circumference of the stricture. Whereas
there is evidence that this may be a viable approach in select cases,
such procedures should only be performed by interventional endoscopists with considerable expertise and in settings with the appropriate radiologic and surgical backup.
Lastly, the use of a LAMS for benign gastrointestinal strictures
has emerged as an alternative to other traditional endoscopic
therapies. The unique design, short length, saddle shape, and
wide flange at each end are design features that facilitate stent
retention, which improves patient tolerance and makes them less
prone to migration (Fig. 3). Their safety and long-term efficacy
data are lacking; however, they might be an alluring prospect for
benign strictures. With an increasing interest in endoscopic intraluminal surgery, newer technologies will undoubtedly become
available in the future. The management of colonic obstruction is
summarized in Figure 4.
CONTRAINDICATIONS
TO COLONIC STENTS
The absolute contraindications to stent placement include the
presence of colonic perforation or severe colonic ischemia with
impending necrosis, which can be assessed with a thorough physical
examination and radiologic imaging. Other contraindications are
summarized in Table 1.
Technical Considerations
Types of Colonic Stents
Currently all commercially available SEMS for MCO are uncovered because of the high rate of migration associated with covered
SEMS. Most commercially available SEMS work with the same
mechanism; the main features to consider include stent dimensions, material, design, and delivery system. The various types of
colonic stents are summarized in Table 2.
Benign
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Colonic Obstruction
Graded EBD +/-Intralesional
steroid injections
FCEMS
Endoscopic incisional
therapies- needle knife
LAMS
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Bridge to surgery
219
SEMS
Malignant
Emergency Surgery
FIG. 4 Summary of management of colonic obstruction/stricture.
Palliative therapy
Extrinsic compression
TABLE 1 Contraindications to SEMS Placement
Contraindication
Absolute
Relative • Distalrectallesionswith5cmfromthedentateline(stentscrossingtheanalvergecaninduceseverepain,
Special
considerations
SEMS, Self-expandable metal stent
• Colonicperforationorseverecolonicischemiawithimpendingnecrosis
tenesmus, bleeding, and risk of migration)
• Presenceofdiffuseperitonealcarcinomatosis(higherfailurerate)
• Persistentseverecoagulopathy(riskofbleeding)
• Tumorsclosetotheanalverge(<5cm)
• Lesionsintortuousorangulatedportionsofthecolon,suchasthesplenicflexure(technicallychallengingandmay
have a higher failure rate)
• Theuseofprophylacticstentsinpatientswithmetastaticdiseasetopreventpotentialobstructionisnotrecommended.
• Right-sidedorproximalcoloniclesionsarebettermanagedwithsurgicalresectionwithprimaryanastomosisor
stoma creation. Although SEMS placement is performed in some palliative cases, it is not recommended given the
technical challenges and non-inferiority to surgery.
TABLE 2 Various Types of Colonic Stents
Manufacturer Model Name Stent Covering
Boston Scientific WallFlex colonic* Uncovered TTS, 10F Nitinol 22, 25/27, 30 60, 90, 120
Taewoong Medical Niti-S enteral
Ultraflex preci-
sion colonic*
Wallstent colonic
and duodenal
endoprosthesis*
colonic D type*
Niti-S Enteral
Colonic S-type*
Delivery
System Material
Uncovered Non-TTS,
Nitinol 25/30 (proximal
OTW, 16F
Uncovered TTS, 10F Stainless
Uncovered TTS, 10F Nitinol 18, 20, 22, 24, 26, 28/,
Body Diameter/Flange
Diameter (mm) Length (mm)
flange)
20, 22/Minimal, no
steel
flare
57, 87, 117
60, 90, 120
60, 80, 100, 120
no flare
Partially covered TTS, 10F Nitinol 20, 22/28, 30 60, 80, 100,120
Partially covered NON-TTS Nitinol 22, 24, 26, 28/30, 32, 34 60, 80, 100, 120
Continued
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TABLE 2 Various Types of Colonic Stents—cont’d
Delivery
Manufacturer Model Name Stent Covering
Cook Endoscopy Evolution colonic* Uncovered TTS Nitinol 25/30 60, 80,100
M.I. Tech Hanarostent
colon/rectum*
Choostent
colon/rectum
(CCC)
EndoChoice Bonastent Uncovered/partially
ELLA-CS SX-ELLA colorec-
tal (Enterella)
S & G Biotech EGIS colorectal Covered single or double TTS, 10F Nitinol 20, 22 60, 80, 100, 120
Hercules SP col-
orectal stent
dual type
Leufen Medizintechnik
OHG
MICRO-TECH
Europe (Dusseldorf,
Germany)
Ecostent Uncovered Non-TTS Nitinol 30/36 both ends flared 8, 10
MICRO-TECH
colon and rectum stent
Uncovered and fully
covered
Fully covered NON-TTS Nitinol 22, 24/30, 32, both
covered
Uncovered and
covered
Inner uncovered, outer
partially covered
Composed of two
separate stents
sequentially deployed
Uncovered and par-
tially covered
System Material
TTS: 10.2F, 10.5F;
NON-TTS 24F
TTS, 10F and
12F
Non-TTS, 15F
(uncovered),
18F (covered)
Non-TTS Nitinol 28 outer, 18 inner 110, 130,
TTS, non-TTS Nitinol 30/36
Nitinol 20, 22, 24/26, 28, 30 60, 70, 80, 90, 100,
Nitinol 22, 24, 26 60, 80, 100
Nitinol 20, 22, 25 82, 90, 113, 135
Body Diameter/Flange
Diameter (mm) Length (mm)
110, 120, 130,
140, 150, 160
100, 180
ends flanged; available symmetric and
asymmetric
150, 170,
190(outer)
8, 10, 12
25/30(covered)
*FDA approved
Stent Dimensions
The uncovered stents in the United States come in sizes that fall between
5.7 and 12 cm in length and mid-body diameters of 20 to 30 mm (with
variably flanged ends that are wider than the width of the stent body)
after deployment. They come within a 10Fr catheter that fits through the
accessory channel of an adult colonoscope or a therapeutic gastroscope
(with a channel diameter of at least 3.7 mm), which allows for the stent
to be placed using both endoscopic and fluoroscopic visualization.
Stent Material
SEMS are composed of a radiopaque, woven, metal mesh with a
cylindrical shape that exerts self-expansion forces. In their unexpanded form, they fit through the channel of an endoscope. Following deployment to the desired location, they expand to oppose the
luminal surface of interest. Although the basic delivery system and
deployment mechanism are identical, stents are classified based on
their coating and manufacture material.
Stents are made from stainless steel or other alloys such as Nitinol (comprising nickel and titanium) or Elgiloy (comprising cobalt,
chromium, and nickel). Nitinol is the most widely used metal alloy.
Its main advantage over other stent materials is its malleability at low
temperatures and strong radial forces at body temperature without
losing its flexibility (Fig. 5). Stainless steel stents are relatively stiff
and may affect the quality of imaging studies such as MRI. Stents
made of Elgiloy are thinner, more elastic, and more flexible, and they
are MRI-compatible with less imaging artifact.
Covered versus Uncovered Stents
Uncovered stents have bare wires, while covered stents have a silicone
membrane over the bare wires. Covered stents can be subdivided into
fully and partially covered stents. Although covered stents reduce the risk
of tumor ingrowth and can be used to seal fistulas, fully covered stents
have less anchoring power and an increased risk of migration compared
with uncovered stents. Partially covered stents with flared uncovered segments at both ends were developed to overcome migration risk. Patency
rates between uncovered and covered SEMS are thought to be similar,
however more data are required to validate these findings. In a systemic
review and meta-analysis by Mashar et al. (1 RCT and 9 observational
studies including 753 patients) comparing covered and uncovered stents
in management of MBO, uncovered stents were associated with a lower
risk of complications (RR 0.57, 95% CI 0.44–0.74, P<0.0001), tumor
overgrowth (RR 0.29, 95% CI 0.09–0.93,P
(RR 0.29, 95% CI 0.17–0.48,P< 0.00001); longer duration of patency
(MD 18.47, 95% CI 10.46–26.48, P < 0.00001); lower need for stent
reinsertion (RR 0.38, 95% CI 0.17–0.86,P
tumor ingrowth (RR 4.53, 95% CI 1.92–10.69, P = 0.0008). Rates of
technical success (RR 1.02, 95% CI 0.99–1.04,P = 0.21), clinical success
(RR 1.03, 95% CI 0.98–1.08,P = 0.32), perforation (RD 0.01, 95% CI
0.03–0.02, p = 0.65), bleeding (RD 0.00, 95% CI 0.03–0.03, P = 0.98),
stool impaction (RR 0.56, 95% CI 0.12–2.04, P = 0.38), and stent
obstruction (RR 2.23, 95% CI 0.94–5.34,P = 0.97) were similar. These
results concluded that uncovered stents were superior in the management of MBO. It is worth mentioning that only uncovered colonic
SEMS are available in the United States.
= 0.04), and stent migration
= 0.02); and higher risk of
Technical Aspects of Stent Deployment (Box 1)
Pre-stent placement
Before performing colonic SEMS placement, one should assess the
location and morphology of the stricture (Fig. 6). The imaging modalities commonly used include a retrograde water-soluble contrast enema
(barium enema or Gastrografin) (Bracco Diagnostics Inc., Monroe
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FIG. 5 Various types of self-expandable uncovered metal colonic stents. (From Baron TH, Wong Kee Song LM, Repici A. Role of self-expandable stents for patients
with colon cancer (with videos). Gastrointest Endosc. 2012;75:653–662.)
Township, NJ) or cross-sectional imaging (CT scan). These imaging
modalities can help delineate the anatomy (number, length, location,
and degree of stricturing) and in some cases reveal synchronous proximal lesions and rule out the presence of a leak or perforation. CT scans
can also assist with defining the surrounding soft tissue, lymph nodes,
and more distant organs, which can be critical in cases of mass lesions,
as well as in inflammatory bowel disease, which can be further complicated by fistulas or abscesses. Patients are usually given one or two
cleansing enemas to prepare the distal colon. Oral bowel prep should be
avoided as it may worsen the symptoms of obstruction. In some cases,
BOX 1 Technical Aspects of Stent Placement
Prerequisites
Thorough history and physical examination; rule out perforation
Assess location and morphology of stricture with contrasted
imaging:
Retrograde barium/Gastrografin enema or CT with contrast
Avoid oral mechanical bowel prep; consider enemas
Diagnostic colonoscopy (some cases)
a diagnostic colonoscopy is warranted in determining the etiology of a
stricture as it can help obtain sampling for pathologic diagnosis.
In patients with complete obstruction and dilated colon proximally, prophylactic intravenous antibiotic therapy is recommended
by the surgical societies. It is postulated that during insufflation for
stent deployment, the increase of wall tension and intestinal barrier
damage may cause microperforations resulting in bacterial translocation. However, several studies report a negligible risk of infection
within 48 hours post-stenting. Likewise, Kim et al. performed a propensity score-matched analysis of prophylactic antibiotics for colonic
stenting that did not show significant differences in infectious
complications (such as fever, bacteremia, and systemic inflamma-
Intraprocedural
Endoscopy suite or operating room
General anesthesia preferred
Left lateral position
Therapeutic gastroscope or colonoscope (depending on location)
CO
insufflation
2
Stent Deployment
Combined endoscopy and fluoroscopy technique
TTS stent deployment with guidewire
tory response syndrome) between patients who received antibiotic
prophylaxis and those who did not. The ESGE and ASGE do not
recommend the routine use of antibiotic prophylaxis.
Stent Deployment Process
Post-stent care
Confirm large bowel decompression on endoscopy
Post-procedure imaging (x-ray or CT)
Repeat x-ray in 2 days to confirm stent expansion and position
The procedure is usually carried out in the endoscopy suite or operating room depending on the physician performing the procedure.
TTS, Through the scope.
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A
FIG. 6 Morphology of colonic stricture with apple core lesion, pathognomic for colonic adenocarcinoma. (A) Barium enema showing morphology of colonic
stricture. (B) CT abdomen and pelvis (sagittal view) with intravenous and intraluminal contrast showing a colonic stricture (arrow). (From Copland AP, Wang AW.
Clinical Gastrointestinal Endoscopy 3rd ed. Chapter 40: Colonic Strictures.)
B
FIG. 7 Through-the-scope (TTS) colonic self-expandable metal stent placement process. The endoscope is passed to the lesion, and a guidewire is
advanced across the obstruction (far left).(A) The catheter is advanced across the lesion. (B) The predeployed stent is advanced through the endoscope
channel and across the lesion. (C) The restraining sheath is withdrawn. (D) The stent is fully deployed. (From Baron TH, Wong Kee Song LM, Repici A. Role of
self-expandable stents for patients with colon cancer (with videos). Gastrointest Endosc. 2012;75:653–662.)
Anesthesia choice is based on physician preference, but intubation
is recommended in cases of acute colonic obstruction given the risk
of aspiration during the procedure. Patients are placed in the left
lateral position to facilitate passage of the endoscope. For left-sided
colonic strictures, a therapeutic gastroscope is often the instrument
of choice, but for more proximal or right-sided strictures, an adult
colonoscope may be required. CO
as CO
is more rapidly absorbed and leads to reduced abdominal
2
discomfort and may decrease the risk of perforation.
A SEMS can be loaded using two different delivery systems:
through-the-scope (TTS) stents or over-the-wire (OTW) stents. TTS
insufflation is preferred over air
2
stents are traditionally loaded into 10Fr catheters, introduced over
the guidewire, and placed across the stricture under endoscopic and
fluoroscopic guidance. OTW stents are passed over the guidewire and
placed under fluoroscopic visualization. The use of simultaneous sideby-side endoscopy with a small-caliber endoscope is recommended
in some cases but not mandatory. This technique is preferred in case
of rectal or sigmoid strictures, acute angulations, or other conditions
with poor endoscopic visualization. Both fluoroscopic and endoscopic
guidance is preferred as fluoroscopy not only assists in defining the
stricture but also adjunctively guides stent placement. TTS colonic
SEMS placement is illustrated in Figure 7 and Video 1.
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TABLE 3 Technical Tips for Stent Deployment and Guidewire Passage
Instrument Technical Tip
Triple-lumen biliary
occlusion (stone
retrieval) catheter
Guidewires Using hydrophilic biliary guidewires (e.g., Glidewire; Boston Scientific)
Cap, sphincterotome For lesions at flexures or corners, a clear cap to obtain a more en face view and a sphincterotome, preferably a
Stent deployment SEMS should be of suitable length to bridge the stricture and extend at least 2 cm on each side of the
On reaching the stricture, a guidewire with a hydrophilic soft/
floppy tip (typically a 0.035-inch-diameter guidewire for added stiffness) is passed across the stricture. Careful guidewire passage and
measuring the appropriate stricture length are key steps to technical
success of the stent deployment process. A few additional technical
tips are described in Table 3.
Deployment of TTS uncovered or covered metal stents follows
similar principles and involves an assistant deploying the stent
while the endoscopist pulls back on the restraining catheter until
the stent is released. The stent is then deployed by withdrawing the
constraining sheath or unraveling string (depending on the device).
Most colonic SEMSs deploy from a proximal (oral) to distal (rectal)
fashion. Although there is no validated rule for stent deployment,
it is recommended that the SEMS should be of suitable length to
bridge the stricture and extend at least 2 cm on each side of the
obstruction once the stent is deployed. One must also account for
the degree of shortening that occurs during deployment and stent
migration away from the endoscope. If stent coverage is inadequate, an additional stent can be deployed overlapping the existing
stent. It is important to keep the wire in place across the lesion
until the final position of the stent is assessed radiographically
because passing a wire through a newly deployed stent can be technically challenging. In patients who present with complete colonic
obstruction, consideration should be given to leaving the guidewire
in place after stent deployment to pass a colonic decompression
tube through the stent and into the proximal bowel if immediate
passage of stool does not occur after stent placement. For rightsided colonic obstruction, stents can also be successfully placed
proximally, although the lesions typically require a TTS SEMS
placed via an adult colonoscope.
After stent deployment, additional balloon dilation is not recommended because it is associated with a high risk of perforation.
Because of the nature of the self-expansion, stents are allowed to
slowly expand over time. The peristaltic movements of the colon
after decompression may facilitate full expansion. Immediately after
stent placement, the enema examination can be repeated to document post-stenting patency and correct positioning, although this is
not always needed.
FOLLOW-UP CARE
Immediately following stent placement, large bowel decompression,
confirmed on endoscopy, is suggestive of successful deployment of
a stent. If a nasogastric tube is present, it can often be removed the
following day. A postprocedural abdominal radiograph or CT is
Method 1: Catheter with the balloon inflated to 12–15 mm and positioned just distal to or impacted at the
obstruction site followed by stricturogram
Method 2: Biliary stone retrieval balloon passed beyond the stricture and then inflated to a large-diameter 12–15
mm, and balloon is withdrawn until it abuts the proximal shelf of the stricture meeting resistance. The endoscopist then holds the catheter at the biopsy port. The balloon is deflated and withdrawn while keeping the finger position on the catheter. When the balloon is seen endoscopically on the distal aspect of the stricture, the
distance from the endoscopist’s fingers to the biopsy port corresponds to the length of the stricture.
rotatable sphincterotome (e.g., Autotome RX; Boston Scientific), are used to orient the catheter in the direction of the lumen.
obstruction.
Keep in mind the degree of SEMS shortening during deployment and stent migration away from the endoscope.
FIG. 8 Postprocedural abdominal radiograph demonstrating a well-posi-
tioned transverse colon stent across a malignant stricture.
obtained immediately after stent placement to confirm position and
exclude free air (Fig. 8). An abdominal x-ray is repeated within 24 to
48 hours when full expansion of the stent is expected. A liquid diet
can typically be initiated within 24 to 48 hours of stent placement in
most patients. Several days are needed for complete decompression
to a normal-sized colon.
OUTCOMES AND ADVERSE EVENTS
The mortality rate of colonic stenting is roughly 1.5% to 3%.
Technical success (immediate or short-term success) is defined
223
224 ENTERAL STENTS IN THE TREATMENT OF COLONIC OBSTRUCTION
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FIG. 9 (A) Endoscopic view of carcinoma ingrowth with obstruction
of stent 6 months after initial deployment. (B) Successful fulguration
of carcinoma ingrowth inside the stent using argon plasma coagulation.
(C) Rectosigmoid resection specimen reveals stent erosion.
as the ability to safely deploy and properly position the stent across
the stricture without any immediate complication. Clinical success
(long-term success) is defined as the ability to achieve long-term
decompression without the need for operative intervention to treat
long-term failure of the stent or related complications. Colonic stenting has a high technical success of 80% to 100% and clinical success
of 70% to 100%. The rates of complications are variable across studies
but can be broadly divided into early (<2 weeks) and late (>2 weeks)
complications, with an overall complication rate of 10% to 15%.
Early Complications
Perforation
The most feared complication is perforation. The rate of perforation
in malignant obstruction is 6% across various studies, while that of
silent or microperforations is up to 14%. Angiogenesis inhibitors (e.g.,
bevacizumab) are independent risk factors of perforation, even in the
absence of stenting, and are known to increase the rate of perforation
to 12.8%. The ESGE does not recommend the combination therapy of
stent with antiangiogenic drugs (Fig. 9). Perforation rates are highest
in colonic SEMS deployment for benign strictures (18%). When large
perforations occur, they are best managed operatively. Microperforations may be managed with bowel rest and intravenous antibiotics.
(inadequate stricture coverage), incomplete expansion, or undetected synchronous tumors. Stent migration rates are determined by
the type of stent deployed, the degree of stenosis, the proximal and
distal clearance, and the flare diameter. Short stents, smaller-diameter stents (<25 mm), and covered stents have higher rates of migration. SEMS migration can typically be managed endoscopically by
removing the migrated stent with the goal of either placing a larger
stent or a different type of stent that might be less prone to migration.
Other alternatives to replacing a migrated SEMS include observation
(particularly if the stricture has become more patent following stenting) or more definitive surgical intervention.
Abdominal/Rectal Pain and Incontinence
Abdominal/rectal pain and incontinence may occur if stents are
placed within 5 cm of the anal verge. Pain is also commonly caused
by mucosal irritation from the stent itself. Bleeding may occur in
up to 5% of patients. This is usually mild to moderate in severity,
however endoscopic interventions are recommended before surgery.
Late Complications
Late stent migration can be seen in cases following chemotherapy or
radiotherapy with subsequent tumor shrinkage.
Stent Migration and Failure
Failure of the stent to resolve the obstruction and early stent migration (seen in 4%–11.7%) should raise suspicion for stent malposition
Occlusion by Fecal Impaction and/or Tumor Ingrowth
Tumor ingrowth has been reported in 15% of patients. Although
most patients currently treated with palliative stents succumb to their
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disease before obstructing, the impact of newer chemotherapeutic
agents on long-term survival may affect the rate of this long-term
complication. Tumor ingrowth and fecal impaction of the stent can
be managed endoscopically by placing another stent through the
occluded stent.
CONCLUSION
Colonic SEMS are an important part of the treatment armamentarium of managing obstructing colorectal cancer. It is a
relatively safe and effective procedure that is used for palliation
of obstruction and as a bridge to a safer, less morbid surgery. As
newer technologies and medical therapies continue to evolve, surgeons and gastroenterologists must work in close collaboration to
appropriately select patients who would most benefit from these
interventions.
S u g g e S t e d R e a d i n g S
Abelson JS, Yeo HL, Mao J, Milsom JW, Sedrakyan A. Long-term postproce-
dural outcomes of palliative emergency stenting vs stoma in malignant
large-bowel obstruction. JAMA Surg. 2017;152(5):429–435.
Allievi N, Ceresoli M, Fugazzola P, Montori G, Coccolini F, Ansaloni L.
Endoscopic stenting as bridge to surgery versus emergency resection for
left-sided malignant colorectal obstruction: an updated meta-analysis. Int
J Surg Oncol. 2017;2017:2863272.
Ansaloni L, Andersson RE, Bazzoli F, etal. Guidelenines in the management
of obstructing cancer of the left colon: consensus conference of the World
Society of Emergency Surgery (WSES) and Peritoneum and Surgery (PnS)
Society. World J Emerg Surg. 2010;5:29.
Arezzo A, Forcignanò E, Bonino MA, etal. Long-term oncologic results after
stenting as a bridge to surgery versus emergency surgery for malignant
left-sided colonic obstruction: a multicenter randomized controlled trial
(ESCO Trial). Ann Surg. 2020;272(5):703–708.
Baron TH, Wong Kee, Song LM, Repici A. Role of self-expandable stents
for patients with colon cancer (with videos). Gastrointest Endosc.
2012;75(3):653–662.
Caruso A, Conigliaro R, Manta R, etal. Fully covered self-expanding metal
stents for refractory anastomotic colorectal strictures. Surg Endosc.
2015;29(5):1175–1178.
Cirocchi R, Farinella E, Trastulli S, et al. Safety and efficacy of endoscopic
colonic stenting as a bridge to surgery in the management of intestinal
obstruction due to left colon and rectal cancer: a systematic review and
meta-analysis. Surg Oncol. 2013;22(1):14–21.
Faraz S, Salem SB, Schattner M, etal. Predictors of clinical outcome of colon-
ic stents in patients with malignant large-bowel obstruction because of
extracolonic malignancy. Gastrointest Endosc. 2018;87(5):1310–1317.
Ferrada P, Patel MB, Poylin V, etal. Surgery or stenting for colonic obstruc-
tion: A practice management guideline from the Eastern Association for
the Surgery of Trauma. J Trauma Acute Care Surg. 2016;80(4):659–664.
Foo CC, Poon SHT, Chiu RHY, Lam WY, Cheung LC, Law WL. Is bridge
to surgery stenting a safe alternative to emergency surgery in malignant
colonic obstruction: a meta-analysis of randomized control trials. Surg
Endosc. 2019;33(1):293–302.
Frago R, Ramirez E, Millan M, Kreisler E, del Valle E, Biondo S. Current man-
agement of acute malignant large bowel obstruction: a systematic review.
Am J Surg. 2014;207(1):127–138.
Huang X, Lv B, Zhang S, Meng L. Preoperative colonic stents versus emer-
gency surgery for acute left-sided malignant colonic obstruction: a
meta-analysis. J Gastrointest Surg. 2014;18(3):584–591.
Jain D, Sandhu N, Singhal S. Endoscopic electrocautery incision thera-
py for benign lower gastrointestinal tract anastomotic strictures. Ann
Gastroenterol. 2017;30(5):473–485.
Kim EJ, Kim YJ. Stents for colorectal obstruction: Past, present, and future.
World J Gastroenterol. 2016;22(2):842–852.
Kim JS, Lee WS, Chung CY, etal. Clinical impact of prophylactic antibiotic treat-
ment for self-expandable metallic stent insertion in patients with malignant
colorectal obstruction. Gastroenterol Res Pract. 2015;2015:416142.
Lee KM, Shin SJ, Hwang JC, etal. Comparison of uncovered stent with cov-
ered stent for treatment of malignant colorectal obstruction. Gastrointest
Endosc. 2007;66(5):931–936.
Legnani PE, Kornbluth A. Therapeutic options in the management of stric-
tures in Crohn’s disease. Gastrointest Endosc Clin N Am. 2002;12(3):589–
603.
Mashar M, Mashar R, Hajibandeh S. Uncovered versus covered stent
in management of large bowel obstruction due to colorectal malignancy: a systematic review and meta-analysis. Int J Colorectal Dis.
2019;34(5):773–785.
Naveed M, Jamil LH, Fujii-Lau LL, etal. American Society for Gastrointestinal
Endoscopy guideline on the role of endoscopy in the management of
acute colonic pseudo-obstruction and colonic volvulus. Gastrointest
Endosc. 2020;91(2):228–235.
Neo VSQ, Jain SR, Yeo JW, etal. Controversies of colonic stenting in obstruc-
tive left colorectal cancer: a critical analysis with meta-analysis and
meta-regression. Int J Colorectal Dis. 2021;36(4):689–700.
Phillips RK, Hittinger R, Fry JS, Fielding LP. Malignant large bowel obstruc-
tion. Br J Surg. 1985;72(4):296–302.
Pirlet IA, Slim K, Kwiatkowski F, Michot F, Millat BL. Emergency preop-
erative stenting versus surgery for acute left-sided malignant colonic
obstruction: a multicenter randomized controlled trial. Surg Endosc.
2011;25(6):1814–1821.
Pisano M, Zorcolo L, Merli C, etal. 2017 WSES guidelines on colon and
rectal cancer emergencies: obstruction and perforation. World J Emerg
Surg. 2018;13:36.
Ribeiro IB, Bernardo WM, Martins BDC, etal. Colonic stent versus emer-
gency surgery as treatment of malignant colonic obstruction in the
palliative setting: a systematic review and meta-analysis. Endosc Int Open.
2018;6(5):E558–E567.
Ribeiro IB, de Moura DTH, Thompson CC, de Moura EGH. Acute abdom-
inal obstruction: Colon stent or emergency surgery? An evidence-based
review. World J Gastrointest Endosc. 2019;11(3):193–208.
Saida Y. Current status of colonic stent for obstructive colorectal cancer in
Japan; a review of the literature. J Anus Rectum Colon. 2019;3(3):99–105.
Saif MW, Elfiky A, Salem RR. Gastrointestinal perforation due to bevacizum-
ab in colorectal cancer. Ann Surg Oncol. 2007;14(6):1860–1869.
Shin SJ, Kim TI, Kim BC, Lee YC, Song SY, Kim WH. Clinical appli-
cation of self-expandable metallic stent for treatment of colorectal
obstruction caused by extrinsic invasive tumors. Dis Colon Rectum.
2008;51(5):578–583.
Sloothaak DA, van den Berg MW, Dijkgraaf MG, etal. Oncological outcome
of malignant colonic obstruction in the Dutch Stent-In 2 trial. Br J Surg.
2014;101(13):1751–1757.
Spannenburg L, Sanchez Gonzalez M, Brooks A, et al. Surgical outcomes
of colonic stents as a bridge to surgery versus emergency surgery for
malignant colorectal obstruction: A systematic review and meta-analysis
of high quality prospective and randomised controlled trials. Eur J Surg
Oncol. 2020;46(8):1404–1414.
Spinelli P, Dal Fante M, Mancini A. Self-expanding mesh stent for endoscopic
palliation of rectal obstructing tumors: a preliminary report. Surg Endosc.
1992;6(2):72–74.
Tan CJ, Dasari BV, Gardiner K. Systematic review and meta-analysis of
randomized clinical trials of self-expanding metallic stents as a bridge to
surgery versus emergency surgery for malignant left-sided large bowel
obstruction. Br J Surg. 2012;99(4):469–476.
van Hooft JE, Bemelman WA, Oldenburg B, etal. Colonic stenting versus
emergency surgery for acute left-sided malignant colonic obstruction: a
multicentre randomised trial. Lancet Oncol. 2011;12(4):344–352.
van Hooft JE, Veld JV, Arnold D, et al. Self-expandable metal stents
for obstructing colonic and extracolonic cancer: European Society of
Gastrointestinal Endoscopy (ESGE) Guideline—Update 2020. Endoscopy.
2020;52(5):389–407.
Wang X, He J, Chen X, Yang Q. Stenting as a bridge to resection versus emer-
gency surgery for left-sided colorectal cancer with malignant obstruction:
A systematic review and meta-analysis. Int J Surg. 2017;48:64–68.
Webster PJ, Aldoori J, Burke DA. Optimal management of malignant left-sid-
ed large bowel obstruction: do international guidelines agree?. World J
Emerg Surg. 2019;14:23.
Ye GY, Cui Z, Chen L, Zhong M. Colonic stenting vs emergent surgery for
acute left-sided malignant colonic obstruction: a systematic review and
meta-analysis. World J Gastroenterol. 2012;18(39):5608–5615.
Zhang Y, Shi J, Shi B, Song CY, Xie WF, Chen YX. Comparison of efficacy
between uncovered and covered self-expanding metallic stents in malignant large bowel obstruction: a systematic review and meta-analysis.
Colorectal Dis. 2012;14(7):e367–e374.
226 MANAGEMENT OF ACUTECOLONIC PSEUDO-OBSTRUCTION (OGILVIE’S SYNDROME)
https://t.me/med1917
Management of
AcuteColonic
Pseudo-Obstruction
(Ogilvie’s Syndrome)
Marshall S. Bedine, MD
cute colonic pseudo-obstruction (ACPO), often known as Ogilvie’s
syndrome, is a condition of sudden onset associated with an acute
A
dilation of the colon with no evidence of mechanical obstruction. The
syndrome was first reported by William Ogilvie in 1948.
Pathogenesis of ACPO has been thought to be related to
impairment of the autonomic nervous system leading to an atonic
distal colon and functional obstruction. When this occurs, colonic
diameter increases with a rise in tension on the colonic wall. This,
in turn, increases the risk of colonic ischemia and perforation as
the colon dilates and cecal diameter exceeds 10 to 12 cm. Ischemia
with or without perforation increases rapidly as the colon dilates,
particularly if the duration of distention exceeds 6 days.
ACPO most often occurs in hospitalized or institutionalized
patients usually with severe comorbid illness. Associated conditions include infection, cardiac disease, and inoperative trauma
as well as orthopedic procedures including hip and spine surgery
or after pelvic surgery. In one study, 92% of postpartum cases of
ACPO were in patients following cesarean section after complicated pregnancies. The incidence of ACPO is approximately 1:1000
of hospitalized patients. If colonic ischemic or perforation occur,
the mortality may be as high as 50%.
CLINICAL MANIFESTATIONS AND
DIAGNOSIS
Clinical manifestations of ACPO may occur gradually or rapidly
with abdominal pain occurring in 80% of patients associated with
distention. Nausea and vomiting are frequent, and constipation or
even diarrhea has been reported in 40% to 50%.
Physical examination reveals a protuberant abdomen that is
tympanic to percussion and associated with bowel sounds in up
to 90% of patients. Fever, abdominal tenderness, and peritoneal
signs are worrisome and suggest colonic ischemia or impending
perforation.
The diagnosis of ACPO is made on imaging studies. CT of the
abdomen and pelvis typically demonstrate proximal colon dilation
with an intermediate transition zone near the splenic flexure (Fig. 1).
Occasional dilation may extend to the rectum. This will exclude a
mechanical obstruction. Plain abdominal films can be used to monitor interval changes of colonic dilation (Fig. 2). Contrast enemas
can be hazardous and may increase the risk of perforation. Stool
cultures and stool evaluation for Clostridioides difficile toxin should
be obtained. Hypokalemia, hypocalcemia, and hypomagnesemia are
common and should be corrected. The differential diagnoses include
acute mechanical obstruction, toxic megacolon, and chronic intestinal pseudo-obstruction.
MANAGEMENT
Initial management of ACPO should include keeping the patient
NPO, attempting decompression with nasogastric and rectal tube
suction, and avoiding inciting medications such as opioids, anticholinergics, antipsychotics, cytotoxic drugs, calcium channel blockers,
and clonidine (Fig. 3). Fluid and electrolyte imbalance should be
corrected. Mobilizing the patient, if possible, should be considered.
Positioning the patient in a prone position with hips elevated can
be helpful in allowing the patient to pass gas for relief of distention.
These maneuvers should be considered for 24 to 48 hours as long
as the patient is undergoing frequent physical examinations and
abdominal films at 12-hour intervals. The response to conservative
management may vary between 20% and 92%. A surgical consultation should be obtained as soon as a diagnosis has been made to
guarantee optimal care (Box 1).
When conservative management is ineffective, pharmacologic agents
should be considered. The primary pharmacologic treatment of ACPO
A B
FIG. 1 CT images of colonic dilation, with arrows denoting transition point in the absence of mechanical obstruction (A), consistent with Ogilvie’s syn-
drome, and a ruler demonstrating cecal diameter at the typical threshold of concern for perforation (12 cm) (B). (From Pereira etal. Ogilvie’s syndrome—acute
colonic pseudo-obstruction. J Visceral Surg. 2015;152:99–105.)
122.50 mm
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