List of Abbreviations
The American Society for Gastrointestinal Endoscopy
Caspase recruitment domain-containing protein 15
Controlled radial expansion
Computed tomography enterography
Endoscopic balloon dilation
Endoscopic retrograde cholangiopancreatography
Examination under anesthesia
Inflammatory bowel disease
Ileal pouch-anal anastomosis
Nonsteroidal antiinflammatory drug
Primary sclerosing cholangitis
Tumor necrosis factor
Dr. Bo Shen is supported by the Ed and Joey Story Endowed Chair.
Stricture is a common complication in Crohn’s disease (CD) and inflammatory bowel disease-related surgeries. The disease phenotype of CD is classified as non-stricturing/non-penetrating (B1), stricturing (B2), or penetrating (B3), by the Montreal Classification. A population-based study showed that 81% of the patients had non-stricturing/non-penetrating disease, 4.6%, had stricturing CD, and 14.0% had penetrating CD, at diagnosis. However, the natural history of CD progresses over time with the majority of patients eventually developing stricturing and/or penetrating complication. Reported cumulative frequencies for the development of either stricture or fistula in CD ranged from 34% to 52% at 5 years, and 40%–70% at 10 years after diagnosis. The majority of the patients would eventually need surgery.
Stricturing CD has been managed with medical, endoscopic and surgical therapies, or combinations. It is believed that pure fibrotic stricture is rare and the inflammatory component of a stricture may be treated by antiinflammatory and immunosuppressive medications. A fibrosis-dominant is usually not amenable to the medical therapy. As a matter of fact, CD patients with dominant stricturing or obstructive symptoms were excluded in the majority of published, large randomized controlled trials in antitumor necrosis (TNF), antiintegrin, or antiinterleukin biologics. Surgical approach, including bowel resection with anastomosis and stricturoplasty, is effective in the management of strictures. However, it is often associated with a high risk of postoperative complications, bowel loss, and disease recurrence.
Between medical and surgical therapy, the emerging endoscopic treatment modalities have recently got the momentum, emerging as a valid option for complications of IBD. In this chapter, we discuss the principle, preparation, and the techniques of endoscopic management for CD-associated stricture and fistula based on current literature and our experiences in a tertiary Endoscopy Center for Inflammatory Bowel Disease (IBD) at the Cleveland Clinic.
In 2013, we proposed a classification system of IBD-related strictures, based on etiology, length, severity, number, characters, and complexity. IBD-related strictures can be classified into following categories: (1) primary (disease associated) versus secondary (e.g., anastomosis, nonsteroidal antiinflammatory drugs, ischemia); (2) short (≤4 cm) versus long (>4 cm), based on the length; (3) single versus multiple; (4) mild versus moderate versus severe; (5) straight versus angulated; (6) with or without prestenotic bowel dilation; (7) inflammatory versus fibrotic versus mixed; (8) ulcerated versus nonulcerated; and (9) simple versus complex (with concurrent fistula or abscess). For detailed description in the classification of stricture please see Chapter 7 .
The main purpose of proposing this classification is to identify the most suitable lesion to be treated with the best modality. The most suitable strictures for EBD treatment are those: (1) being short (<4 cm); (2) single and straight; (3) with the absence of prestenotic bowel dilation; (4) fibrotic without much concurrent inflammation ( Table 13.1 ).
|Candidate Lesions||Lesions to Be Avoided|
|Strictures||Short stricture (<4–5 cm)||Long stricture (≥4–5 cm)|
|Web-like stricture||Spindle-like stricture|
|Single or multiple but straight bowel lumen||Angulated stricture; multiple strictures with angulated lumen; stricture associated with abscess|
|Stricture far away from the fistula orifice of the proximal bowel||Stricture at proximity of the fistula orifice of the proximal bowel|
Stricture is a common complication in patient with CD or IBD surgery. The mainstays of endoscopic treatment for CD stricture are EBD and needle-knife stricturotomy (please see a separate Chapter 14 ). The immediate technical success, defined as the successful passage of the endoscope of the treated stricture, was achieved in 45% in earlier small studies to close to 100% in later larger studies. The majority of the patients remained surgery free at the end of follow-up.
Successful performance of EBD requires training of the endoscopist. In addition, the endoscopy team should prepare patient, room setting, equipment, and suppliers. The endoscopist should prepare a roadmap on the nature of the stricture before inserting endoscope, by reviewing history, previous endoscopy and operative reports, and preprocedural abdominal imaging. Patient’s bowel preparation is critical. Extreme cautions for aspiration in patients with stricture and partial bowel obstruction should be taken. The technical parts of EBD are discussed as follows:
EBD with a fluoroscopic guidance is preferred. The use of fluoroscopy allows for the roadmap of targeted stricture and the orientation of endoscope and balloon catheter. However, the use of fluoroscopy exposes patient, endoscopist, and endoscopy nurses to excessive ionizing radiation, even with personal protective equipment. In addition, fluoroscopy is not always logistically available, especially in the outpatient setting. Therefore, EBD is routinely performed fluoroscopic guidance in the treatment of tight, angulated, and multiple strictures not traversable to endoscope or strictures located at deep bowel.
Retrograde Versus Antegrade Dilation
The through-the-scope (TTS) hydrostatic balloon is most commonly used for the treatment of CD or non-CD–related strictures. There are two fashions of EBD, that is, retrograde and antegrade, which are applied for endoscopically traversable and nontraversable strictures, respectively. Retrograde EBD is always preferred, as the endoscopist can direct visualize the nature of stricture as well as the lumen and mucosa of the bowel segment proximal to the stricture. In retrograde EBD, the scope was pushed through the stricture, often with some resistance, followed by the introduction of the TTS balloon under direct endoscopic view. The scope was withdrawn along with the balloon. Once the balloon’s waist is across the stricture, it is inflated. There should be some degree of bleeding after dilation ( Fig. 13.1 ).
EBD for high-grade or angulated strictures, not traversable to the endoscope, can be challenging. One of the concerns is the blind passage of the balloon through the tight stricture may result in barotrauma from the tip of the balloon, potentially leading to perforation. Antegrade, wire-exchange technique may be attempted. The wire-exchange technique will help the blind trauma. The antegrade, wire-exchange technique involves the gentle passage of a soft guidewire equipped in the balloon, by the endoscopy nurse, while the endoscopist holds the endoscope steady, with the tip of the balloon being targeted to the lumen of stricture. If the endoscopy nurse voices no resistance in passing the guidewire through the stricture, the endoscopist can assume that the wire is within the lumen of the bowel. The endoscopist can push the balloon catheter forward, while the endoscopy nurse pulls back. The balloon catheter-wire exchange takes place over the stricture. Once the balloon is secured across the stricture with a finger of the left hand against the console of endoscope, the wire needs to be pushed forward again out of the tip of the balloon, which help to reduce the risk for perforation from the trauma by the tip of the balloon, in case the short balloon slips forward upon insufflation.
Graded Versus Nongraded Dilation and Duration of Insufflation
The balloon can be insufflated in a graded or nongraded fashion. To minimize the risk for perforation, we routinely perform the dilation in a graded fashion, starting with 16–18 mm balloon and progressing gradually to larger sizes. Therefore, CRE balloon (Boston Scientific, Marlborough, MA) with its capability of graded dilation is preferred. The duration of balloon inflation was determined based on the degree, length, and fibrosis of stricture, lasting between 5 and 20 s.
Short Versus Long Balloons
Two types of balloons, 5.5 and 8 cm, are commonly used. The proper size and length of balloon are chosen, based on the degree, length, and nature of stricture. Each of the balloons has pros and cons. The advantages of the short balloon are: (1) easiness to push and pull back through the operating channel; and (2) ability to reach strictures in the deep intestine via pediatric colonoscope; and (3) the equipped guidewire allows for wire-guided antegrade dilation in tight stricture. The main disadvantage of the short balloon is the difficulty in securing the balloon across the stricture, especially in a long stricture, with a risk of slippery of the balloon. The endoscopist may feel like holding a watermelon seed.
The main advantages of the long balloon are their application in longer stricture and ease for the endoscopist to hold cross the stricture. The main disadvantages of the long balloon are the lack of guidewire and difficulty in pushing through the biopsy channel, especially in small-caliber endoscopes.
Visualization of Stricture During and After Dilation
Some endoscopists may have a sense of security with a direct visualization of the stricture and its disruption through the insufflating balloon ( Fig. 13.2 ). This approach may cause issue of balloon’s forward slippery if the stricture is long and balloon is short. Others may find and can secure the position of the balloon better by not seeing the stricture through the insufflating balloon ( Fig. 13.2 ). There are no published data in the comparison of efficacy and safety between the two approaches. Endoscopist’s personal preference plays a role.
After dilation, we have a tendency to take a second look. The advantages of the second look are the assessment of the technical success of EBD (e.g., an easy passage through the dilated stricture), mucosa and luminal pattern of prestenotic bowel for those undergoing antegrade dilation, and identification and immediate management of procedure-associated complications (such as bleeding and bowel perforation), and the detection and treatment of additional strictures in the proximal segment of the gut. However, there is concern that the second look might result in additional trauma, leading to the complication. Therefore, the endoscopist should exert extreme caution.
Biopsy of Stricture
At the first or inception diagnostic or therapeutic endoscopy, the primary stricture or anastomotic stricture in patients with bowel resection for neoplasia should always be biopsied to exclude malignancy. In addition, those with refractory primary or secondary stricture to EBD or endoscopic stricturotomy should be periodically biopsied. Unfortunately, histologic evaluation is not reliable to differentiate an inflammatory stricture from a fibrotic one or to identification of ischemic component in patients with anastomotic stricture. Web-like strictures often result from medications, such as NSAID, pancreas enzyme supplements, and potassium chloride. Biopsy may show the pattern of mucosal injury, different from that of Crohn’s disease.
Distal Bowel and Anal Strictures
The anorectal area is a special zone for endoscopic treatment. The area is rich in nerve and blood supplies as well as vulnerable organs, such as bladder, vagina, and prostate. This has been a challenge for the endoscopic management in strictures at the distal rectum, distal ileal pouch, and anal canal. The endoscopist should be familiar with the orientation of the distal bowel anatomy when performing endoscopy. In the left lateral position, the anterior wall of the distal bowel is at 4 or 5 o’clock position and the posterior wall is at 10 or 11 o’clock position, if the endoscopist holds the scope straight. The orientation is different when the patient is put on supine position or lithotripsy position in operating room. Instillation of water through biopsy channel will demonstrate the gravity area, which will help the orientation.
EBD or bougie dilation may result in unintended iatrogenic trauma to the anterior wall of the distal bowel or to the adjacent organs, such as bladder and vagina, causing rectovaginal fistula (RVF) or pouch-vaginal fistula (PVF). This is a major disadvantage of EBD or bougie dilation, as the tear is blind and the endoscopist has no control in the location and depth of stricture intended to tear. In contrast, endoscopic stricturotomy can overcome this problem, as it can deliver the therapy to the designated spot and depth of treatment. To ensure a safe procedure, endoscopic stricturotomy needs to be performed along the posterior wall which is next to the presacral space. In addition, patients tolerate endoscopic stricturotomy better than barotrauma from EBD or bougie dilation.
It is important to keep concurrent inflammation at the distal large bowel or anal canal under control before EBD with medical therapy. This can make the stricture in the area more “fibrotic,” to reduce inflammation-associated bleeding from endoscopic therapy. EBD may be performed extremely carefully. The balloon size may be smaller (e.g., 16–18 mm) for female than that (e.g., 18–20 mm) for male patients, to reduce the risk for iatrogenic RVF or PVF. To reduce the discomfort, additional sedation, and topical lidocaine may be applied in the targeted area before EBD treatment. The endoscopist may leave a small open space between the distal tip of the scope and the proximal end of the balloon (the location of anal sphincter) when insufflating the balloon. The motion would allow for the anal sphincter to be minimally disturbed and to reduce discomfort. An endoscopic cap may be used to reduce the interference of view from contracting anal canal muscles during balloon insufflation.
Special Situations for Anastomotic Strictures
Bowel resection and anastomosis is the most commonly performed surgical modalities for CD. The anastomoses can be located at gastrojejunostomy, small bowel, ileocolon, colocolon, and colorectum. The anastomosis is fashioned into end-to-end, end-to-side, side-to-end, and side-to-side patterns.
Ileocolonic resection with ileocolonic anastomosis (ICA) is one of the most commonly performed surgical procedures in patients with CD. Side-to-side anastomosis with an intention of increasing anastomotic area is commonly performed. In this situation, the intubation through ICA can be challenging, as ICA is normally at a tangential view. This may result in difficult in EBD for ICA stricture. The retroflexion and 90-degree techniques may be used for dilation of ICA strictures. The 90-degree angle existing between the neoterminal ileum and side-to-side ICA leads us to develop the “90-degree technique.” The “90-degree technique” can be performed in either antegrade or retrograde fashion. When the balloon is placed across the angulated stricture, the endoscopist pushes the balloon forward, letting the balloon and balloon catheter form a 90-degree angle. It should be pointed out that the transverse staple line in the blind end of ileum is prone to the development of injury or perforation.
Stricture With Concurrent Fistula
Enteroenteric fistula (EEF), for example ileosigmoid fistula, is often associated with a bowel stricture distal to the primary opening of fistula. Whether stricture with associated EEF should be dilated depends on the distance between the stricture and the primary opening of the fistula. If the stricture is far away (>5 cm) from the primary opening of the fistula, gentle balloon dilation of the stricture may be attempted, with the intention to relief the intraluminal pressure and reduce the EEF fistula drainage. If the stricture is close to the fistula opening (<5 cm) or nearby abscess, endoscopic dilation should not be performed, to avoid a double bowel perforation at both the ends of fistula.
Strictures at the distal rectum, distal ileal pouch, or anal canal can be present near fistulae, such as RVF, PVF, and perianal fistula, or near abscess in the pelvis or perianal area. EBD is normally not recommended, due to concern of patient’s discomfort (especially in an outpatient setting), blind barotrauma, and iatrogenic fistula and abscess.
Combined With Other Treatment Modalities
EBD can be used in combination with other treatment modalitie, such as endoscopic stricturotomy. For the stricture close to vital organ, such as stricture at the distal rectum or distal ileal pouch in female patients, we can do an endoscopic stricturotomy with a light incision by a needle knife at the posterior wall of the stricture, followed by EBD. The incision with needle knife is intended to mark the place for balloon tear. The combined electric force (i.e., needle knife) and mechanical force (i.e., EBD) may reduce the risk for bleeding from the pure electric force. In addition, we may place clip(s) to the balloon-torn site at stricture, to prevent reclosure of the stricture ( Fig. 13.3 ).