**2. Diagnosis**

#### **2.1 Ileocolonoscopy**

Colonoscopy with intubation of the terminal ileum and multiple biopsies is recommended as part of the initial evaluation of patients with suspected CD [5]. It has been reported a successful ileal intubation rate as high as % when the cecum is reached [6]. A minimum of two biopsies from five different sites, including the rectum and the ileum, should be obtained for a reliable diagnosis of CD. Samples are preferably obtained both from areas which are involved by the disease and from uninvolved areas. Mucosal changes suggestive of CD include discontinuous segments of edema, friability, ulcerations, fistulous orifices and stenosis (**Figure 1**). With respect to the histological exam, macroscopic and microscopic features include discontinuous chronic inflammation, with lymphocytes and plasma cells, focal crypt distortion and granulomas. Although the presence of granulomatous inflammation is helpful, it is not required for diagnosis and is seen in only 33% of patients with CD [7].

Ileocolonoscopy is also helpful for the detection of stenosis, allowing tissue sampling for pathological diagnosis of dysplasia and cancer. Complementary radiological techniques to rule out additional stenotic lesions are necessary when the lesion is impassable with the endoscope.

Attempts to quantify the distribution and severity of mucosal involvement of the colon and the ileum in patients with CD have led to the development of multiple endoscopic scoring systems. Endoscopic scores that have been validated for ileocolonoscopy include both the Crohn's Disease Endoscopic Index of Severity (CDEIS) [8]

#### **Figure 1.**

*Endoscopic appearance of Crohn's disease - discontinuous segments of edema, friability, ulcerations (A) and stenosis (B and C).*

**29**

**Table 2.**

Presence of narrowing

*Endoscopy in Small Bowel Crohn's Disease DOI: http://dx.doi.org/10.5772/intechopen.95925*

Deep ulceration (0 for none, 12 points if present)

Surface involved by disease (cm)

Surface involved by ulceration (cm)

**Table 1.**

Superficial ulceration (0 for none, 6 points if present)

and the Simple Endoscopic Score for Crohn's Disease (SES-CD) [9]. The CDEIS includes six endoscopic variables (presence of deep ulcers, superficial ulcers, nonulcerated stenosis, ulcerated stenosis, proportion of ulcerated surface and proportion of surface affected by disease), assessed in five bowel segments (terminal ileum, right colon, transverse, left colon and sigmoid, rectum) (**Table 1**). The CDEIS is complicated to use and requires training and experience. Therefore, it is used mainly in clinical trials. On the other hand, the SES-CD has been helpful to translate endoscopic activity into clinically meaningful and is easier to use and understand. The SES-CD includes four variables, each considered in five bowel segments (ulcer size, extent of

> **Transverse colon**

Total 1 + 2 + 3 + 4 Total A Number of segments totally or partially explored n Total A divided by n Total B Quote 3 if ulcerated stenosis anywhere C Quote 3 if nonulcerated stenosis anywhere D Total B + C + D CDEIS

*Crohn's disease endoscopic index of severity (CDEIS). CDEIS includes deep ulceration (no = 0, yes = 12), superficial ulceration (no = 0, yes = 6), surface involved by disease (0–10), ulcerated surface (0–10), and ulcerated or non-ulcerated stenosis (no = 0, yes = 3), each considered in five ileocolonic segments. Severe disease:* 

*CDEIS* ≥*12, moderate disease: CDEIS = 9–12, mild disease: CDEIS = 3–9, remission: CDEIS <3.*

**Variable 0 1 2 3**

Ulcerated surface None <10% 10–30% >30% Affected surface None <50% 50–75% >75%

None Single, can be passed Multiple, can be

*Simple endoscopic score for Crohn's disease (SES-CD). SES-CD = sum of all variables of each explored segment (ileum, right colon, transverse colon, left colon and rectum). Severe disease: SES-CD* ≥*16, moderate disease:* 

(0.2–0.5 cm)

*SES-CD = 7–15, mild disease: SES-CD = 3–6, inactive disease: SES-CD <3.*

Size of ulcers None Aphthous ulcers

**Left colon**

Large ulcers (0.5-2 cm)

passed

**Rectum Sum**

Total 1

Total 2

Total 3

Total 4

Very large ulcers (>2 cm)

Impassible

ulcerated surface, extent of affected surface and stenosis) (**Table 2**).

**colon**

**Ileum Right** 

### *Endoscopy in Small Bowel Crohn's Disease DOI: http://dx.doi.org/10.5772/intechopen.95925*

*Endoscopy in Small Bowel Diseases*

the management of patients with CD.

sis and is seen in only 33% of patients with CD [7].

the lesion is impassable with the endoscope.

**2. Diagnosis**

**2.1 Ileocolonoscopy**

Endoscopy has major implications not only for the diagnosis of CD but also for treatment and follow-up. Indeed, ileocolonoscopy and upper gastrointestinal endoscopy have well-established roles in assessing disease activity and therapeutic intervention. However, the small bowel is one of the most common areas affected in patients with CD, which is often inaccessible to conventional endoscopy. In addition, at the time of diagnosis, up to 30% of patients have only small bowel involvement, especially in the young ones [2, 3]. The advent of video capsule endoscopy and both balloon-assisted and spiral enteroscopy is revolutionizing the management of small bowel CD [4]. In fact, these techniques allowed direct visualization of the entire small bowel which can assist in the diagnosis of CD. Moreover, device-assisted enteroscopy enables direct tissue sampling and allows therapeutic interventions. In this chapter, we aim to review the role of small bowel endoscopy in

Colonoscopy with intubation of the terminal ileum and multiple biopsies is recommended as part of the initial evaluation of patients with suspected CD [5]. It has been reported a successful ileal intubation rate as high as % when the cecum is reached [6]. A minimum of two biopsies from five different sites, including the rectum and the ileum, should be obtained for a reliable diagnosis of CD. Samples are preferably obtained both from areas which are involved by the disease and from uninvolved areas. Mucosal changes suggestive of CD include discontinuous segments of edema, friability, ulcerations, fistulous orifices and stenosis (**Figure 1**). With respect to the histological exam, macroscopic and microscopic features include discontinuous chronic inflammation, with lymphocytes and plasma cells, focal crypt distortion and granulomas. Although the presence of granulomatous inflammation is helpful, it is not required for diagno-

Ileocolonoscopy is also helpful for the detection of stenosis, allowing tissue sampling for pathological diagnosis of dysplasia and cancer. Complementary radiological techniques to rule out additional stenotic lesions are necessary when

Attempts to quantify the distribution and severity of mucosal involvement of the colon and the ileum in patients with CD have led to the development of multiple endoscopic scoring systems. Endoscopic scores that have been validated for ileocolonoscopy include both the Crohn's Disease Endoscopic Index of Severity (CDEIS) [8]

*Endoscopic appearance of Crohn's disease - discontinuous segments of edema, friability, ulcerations (A) and* 

**28**

**Figure 1.**

*stenosis (B and C).*

and the Simple Endoscopic Score for Crohn's Disease (SES-CD) [9]. The CDEIS includes six endoscopic variables (presence of deep ulcers, superficial ulcers, nonulcerated stenosis, ulcerated stenosis, proportion of ulcerated surface and proportion of surface affected by disease), assessed in five bowel segments (terminal ileum, right colon, transverse, left colon and sigmoid, rectum) (**Table 1**). The CDEIS is complicated to use and requires training and experience. Therefore, it is used mainly in clinical trials. On the other hand, the SES-CD has been helpful to translate endoscopic activity into clinically meaningful and is easier to use and understand. The SES-CD includes four variables, each considered in five bowel segments (ulcer size, extent of ulcerated surface, extent of affected surface and stenosis) (**Table 2**).


#### **Table 1.**

*Crohn's disease endoscopic index of severity (CDEIS). CDEIS includes deep ulceration (no = 0, yes = 12), superficial ulceration (no = 0, yes = 6), surface involved by disease (0–10), ulcerated surface (0–10), and ulcerated or non-ulcerated stenosis (no = 0, yes = 3), each considered in five ileocolonic segments. Severe disease: CDEIS* ≥*12, moderate disease: CDEIS = 9–12, mild disease: CDEIS = 3–9, remission: CDEIS <3.*


#### **Table 2.**

*Simple endoscopic score for Crohn's disease (SES-CD). SES-CD = sum of all variables of each explored segment (ileum, right colon, transverse colon, left colon and rectum). Severe disease: SES-CD* ≥*16, moderate disease: SES-CD = 7–15, mild disease: SES-CD = 3–6, inactive disease: SES-CD <3.*

It is important to note that up to 25% of patients have isolated proximal small bowel disease beyond the reach of even complete ileocolonoscopy [10]. Therefore, radiological imaging should be performed in all patients with suspected CD to complement ileocolonoscopy.

#### **2.2 Upper gastrointestinal endoscopy**

The presence of CD of the upper gastrointestinal tract, including the duodenum, is uncommon in adults, with most studies showing a prevalence range of 0.3–5% [11]. Moreover, the majority of patients are asymptomatic at the time of evaluation [12]. However, it is important to note that CD in the proximal gastrointestinal tract is associated with a worse prognosis and there is usually a low threshold to initiate therapy with anti-tumor necrosis factor (TNF).

CD involving the upper gastrointestinal tract is almost invariably accompanied by small or large bowel involvement [13]. Esophagogastroduodenoscopy is recommended in patients with upper gastrointestinal signs and symptoms, being still debated whether asymptomatic adult CD patients should routinely undergo upper endoscopy [6]. In fact, esophagogastroduodenoscopy may support the diagnosis when it is difficult to obtain a histological diagnosis of CD. In addition, a more recent prospective registry reported a higher prevalence of upper gastrointestinal involvement in asymptomatic patients than initially expected, suggesting a place for a standard gastroscopy to correctly evaluate disease extent at diagnosis [12].

Endoscopic features suggestive of upper gastrointestinal involvement include mucosal nodularity, aphthous ulcers, superficial erosions, antral thickening and duodenal strictures [1]. Histologic changes consistent with CD are granulomatous inflammation, focally enhanced gastritis and focal cryptitis of the duodenum.

In the presence of upper tract stenosis, balloon dilatation is recommended as first-line therapy, followed by proton pump inhibitors as second-line and steroids/ thiopurines/surgery as third-line [14]. Currently, there is no credible evidence to support the best modality to assess response to treatment of upper gastrointestinal CD, therefore it must be primarily monitored by the reference standard endoscopy.

#### **2.3 Video capsule endoscopy**

Video capsule endoscopy is a method of endoluminal examination of the small bowel using a wireless capsule-shaped tool which is swallowed and then propelled through the gastrointestinal tract by gut motility [15]. Preparations for a video capsule endoscopy study usually include 8–12 hours' fasting and some method of bowel cleansing (e.g. polyethylene glycol preparation). During the battery life of the capsule, images of the small bowel are recorded and reformatted into a continuous video file. After 8–10 hours, the antenna and storage unit are removed and the images transferred to a computer with specially adapted software. Images are then downloaded, processed and examined by a trained gastroenterologist (**Figure 2**).

In addition to the small-bowel capsule, there are currently two more: the esophageal and the colon capsules [16]. The esophageal capsule is the same size as the small bowel capsule, but has lenses on both ends of the 'pill.' The capsule battery life is only 20 minutes (vs. 8–12 hours for small-bowel capsules), cameras are located on both ends of the capsule and take 18 frames per second (vs. 2–3 frames per second for small-bowel capsules). On the other hand, the second-generation colon capsule endoscope is equipped with two high-resolution cameras providing a viewing angle of 172° in front and back, senses the moving speed of the capsule endoscope and captures 4 to 35 images per second [17]. This capsule was primarily utilized

**31**

tory burden and diagnosis of CD.

*Endoscopy in Small Bowel Crohn's Disease DOI: http://dx.doi.org/10.5772/intechopen.95925*

capsule examination.

**Figure 2.**

*Crohn's disease.*

CD suspicion.

in screening for colonic neoplasia, particularly in situations such as incomplete colonoscopy. However, it can play a key role in the diagnosis and evaluation of CD extent, severity and prognosis, with treatment modifications based on data from

*Video capsule endoscopy images showing mucosal inflammation and ulcerations consistent with a diagnosis of* 

Video capsule endoscopy is a useful adjunct in the diagnosis of patients with small bowel CD since it allows for direct visualization of the mucosa of the entire small intestine. It is able to identify mucosal lesions compatible with CD in patients in whom conventional endoscopic and small bowel radiographic imaging modalities have been nondiagnostic, especially in the proximal small bowel [18]. Several meta-analyses have examined the diagnostic yield of video capsule endoscopy in the evaluation of patients with suspected CD and showed that it is superior to small bowel barium studies, computed tomography enterography and ileocolonoscopy, with an incremental yield of diagnosis of 32%, 47% and 22%, respectively [19]. Moreover, video capsule endoscopy has a negative predictive value of 96%, essentially ruling out small bowel CD [20]. On the other hand, a study examining the sensitivity and specificity of different endoscopic and radiologic exams showed that the specificity of video capsule endoscopy was significantly lower than the other tests [21]. In fact, detected lesions are nonspecific and cannot be distinguished from those seen in patients treated by nonsteroidal anti-inflammatory drugs (NSAIDs). Therefore, video capsule endoscopy should be reserved for cases in which ileocolonoscopy plus small bowel radiography is not diagnostic, but there is a high rate of

Although there are no validated diagnostic criteria for the diagnosis of CD, the presence of more than three small bowel ulcerations, in the absence of NSAIDs ingestion for at least 1 month before the exam, constitutes the most commonly used diagnostic criterion in practice [22]. In addition, there are currently two validated indexes available, the Capsule Endoscopy Crohn's Disease Activity Index (CECDAI) [23] and the Lewis Score [24], which assess the disease location and activity of small bowel involvement. The CECDAI was validated in a multicenter prospective study of patients with isolated small bowel CD and evaluates the following three endoscopic parameters: inflammation, extent of disease and strictures for both the proximal and the distal segments of the small bowel, based on the transit time of the capsule (**Table 3**). The Lewis score is another scoring system based on the evaluation of three endoscopic parameters: villous appearance, ulcers and strictures (**Table 4**). The small bowel is divided into three equal parts and, for each tertile, a subscore is determined. The Lewis Score is the sum of the worst affected tertile plus the stenosis score. Both the scoring systems are incorporated into the software platform of the capsules and assists in the quantification of small bowel inflamma-

**Figure 2.**

*Endoscopy in Small Bowel Diseases*

complement ileocolonoscopy.

**2.3 Video capsule endoscopy**

**2.2 Upper gastrointestinal endoscopy**

therapy with anti-tumor necrosis factor (TNF).

It is important to note that up to 25% of patients have isolated proximal small bowel disease beyond the reach of even complete ileocolonoscopy [10]. Therefore, radiological imaging should be performed in all patients with suspected CD to

The presence of CD of the upper gastrointestinal tract, including the duodenum, is uncommon in adults, with most studies showing a prevalence range of 0.3–5% [11]. Moreover, the majority of patients are asymptomatic at the time of evaluation [12]. However, it is important to note that CD in the proximal gastrointestinal tract is associated with a worse prognosis and there is usually a low threshold to initiate

CD involving the upper gastrointestinal tract is almost invariably accompanied by small or large bowel involvement [13]. Esophagogastroduodenoscopy is recommended in patients with upper gastrointestinal signs and symptoms, being still debated whether asymptomatic adult CD patients should routinely undergo upper endoscopy [6]. In fact, esophagogastroduodenoscopy may support the diagnosis when it is difficult to obtain a histological diagnosis of CD. In addition, a more recent prospective registry reported a higher prevalence of upper gastrointestinal involvement in asymptomatic patients than initially expected, suggesting a place for

a standard gastroscopy to correctly evaluate disease extent at diagnosis [12].

Endoscopic features suggestive of upper gastrointestinal involvement include mucosal nodularity, aphthous ulcers, superficial erosions, antral thickening and duodenal strictures [1]. Histologic changes consistent with CD are granulomatous inflammation, focally enhanced gastritis and focal cryptitis of the duodenum. In the presence of upper tract stenosis, balloon dilatation is recommended as first-line therapy, followed by proton pump inhibitors as second-line and steroids/ thiopurines/surgery as third-line [14]. Currently, there is no credible evidence to support the best modality to assess response to treatment of upper gastrointestinal CD, therefore it must be primarily monitored by the reference standard endoscopy.

Video capsule endoscopy is a method of endoluminal examination of the small bowel using a wireless capsule-shaped tool which is swallowed and then propelled through the gastrointestinal tract by gut motility [15]. Preparations for a video capsule endoscopy study usually include 8–12 hours' fasting and some method of bowel cleansing (e.g. polyethylene glycol preparation). During the battery life of the capsule, images of the small bowel are recorded and reformatted into a continuous video file. After 8–10 hours, the antenna and storage unit are removed and the images transferred to a computer with specially adapted software. Images are then downloaded, processed and examined by a trained gastroenterologist (**Figure 2**). In addition to the small-bowel capsule, there are currently two more: the esopha-

geal and the colon capsules [16]. The esophageal capsule is the same size as the small bowel capsule, but has lenses on both ends of the 'pill.' The capsule battery life is only 20 minutes (vs. 8–12 hours for small-bowel capsules), cameras are located on both ends of the capsule and take 18 frames per second (vs. 2–3 frames per second for small-bowel capsules). On the other hand, the second-generation colon capsule endoscope is equipped with two high-resolution cameras providing a viewing angle of 172° in front and back, senses the moving speed of the capsule endoscope and captures 4 to 35 images per second [17]. This capsule was primarily utilized

**30**

*Video capsule endoscopy images showing mucosal inflammation and ulcerations consistent with a diagnosis of Crohn's disease.*

in screening for colonic neoplasia, particularly in situations such as incomplete colonoscopy. However, it can play a key role in the diagnosis and evaluation of CD extent, severity and prognosis, with treatment modifications based on data from capsule examination.

Video capsule endoscopy is a useful adjunct in the diagnosis of patients with small bowel CD since it allows for direct visualization of the mucosa of the entire small intestine. It is able to identify mucosal lesions compatible with CD in patients in whom conventional endoscopic and small bowel radiographic imaging modalities have been nondiagnostic, especially in the proximal small bowel [18]. Several meta-analyses have examined the diagnostic yield of video capsule endoscopy in the evaluation of patients with suspected CD and showed that it is superior to small bowel barium studies, computed tomography enterography and ileocolonoscopy, with an incremental yield of diagnosis of 32%, 47% and 22%, respectively [19]. Moreover, video capsule endoscopy has a negative predictive value of 96%, essentially ruling out small bowel CD [20]. On the other hand, a study examining the sensitivity and specificity of different endoscopic and radiologic exams showed that the specificity of video capsule endoscopy was significantly lower than the other tests [21]. In fact, detected lesions are nonspecific and cannot be distinguished from those seen in patients treated by nonsteroidal anti-inflammatory drugs (NSAIDs). Therefore, video capsule endoscopy should be reserved for cases in which ileocolonoscopy plus small bowel radiography is not diagnostic, but there is a high rate of CD suspicion.

Although there are no validated diagnostic criteria for the diagnosis of CD, the presence of more than three small bowel ulcerations, in the absence of NSAIDs ingestion for at least 1 month before the exam, constitutes the most commonly used diagnostic criterion in practice [22]. In addition, there are currently two validated indexes available, the Capsule Endoscopy Crohn's Disease Activity Index (CECDAI) [23] and the Lewis Score [24], which assess the disease location and activity of small bowel involvement. The CECDAI was validated in a multicenter prospective study of patients with isolated small bowel CD and evaluates the following three endoscopic parameters: inflammation, extent of disease and strictures for both the proximal and the distal segments of the small bowel, based on the transit time of the capsule (**Table 3**). The Lewis score is another scoring system based on the evaluation of three endoscopic parameters: villous appearance, ulcers and strictures (**Table 4**). The small bowel is divided into three equal parts and, for each tertile, a subscore is determined. The Lewis Score is the sum of the worst affected tertile plus the stenosis score. Both the scoring systems are incorporated into the software platform of the capsules and assists in the quantification of small bowel inflammatory burden and diagnosis of CD.


#### **Table 3.**

*Capsule endoscopy Crohn's disease activity index (CECDAI). CECDAI = proximal segment (A x B + C) + distal segment (A x B+C). Clinical or endoscopic remission: CEDAI <4.*


#### **Table 4.**

*Lewis score. Score total = worst-affected tertile villous appearance and ulcers plus stenosis score. Clinically insignificant inflammation: Lewis score <135, mild inflammation: Lewis score = 135–790, moderate to severe inflammation: Lewis score >790.*

Video capsule endoscopy may also identify a site for directed visualization with other endoscopic techniques. In fact, it can be complementary to device-assisted endoscopy since findings may help direct the most effective route of intubation (oral versus anal), in order to obtain a histopathological diagnosis or therapeutic intervention.

In addition, video capsule endoscopy allows detection of subtle small bowel lesions, which may affect the therapeutic management. Because of the high sensitivity of video capsule endoscopy, it has a potential role in the assessment of mucosal healing after drug therapy and can be used in the follow-up of treated patients. In fact, video capsule endoscopy has a significant impact on disease management and is associated with earlier escalation of therapy. In the largest retrospective series of patients with established CD that were evaluated with video capsule endoscopy, a change in management was suggested in 40–52% of individuals [25, 26].

The main advantage of video capsule endoscopy is the ability to visualize all of the small bowel with minimal discomfort for the patient. However, it lacks therapeutic capabilities and there is some risk of impaction due to possible strictures.

**33**

copy in ease of use and procedural duration [34].

*Endoscopy in Small Bowel Crohn's Disease DOI: http://dx.doi.org/10.5772/intechopen.95925*

**2.4 Device-assisted endoscopy**

tion or general anesthesia.

examination.

overtube.

The capsule retention rate in patients with suspected CD is 1.5–5.4% but can reach 13% in those with established CD, particularly if there are known intestinal stenosis [27, 28]. Therefore, those with obstructive symptoms or established CD of the small bowel should always have small bowel imaging and/or patency capsule evaluation before video capsule endoscopy to decrease the risk of capsule retention. Video capsule endoscopy is considered safe if the patency capsule is excreted before 30 hours, an intact capsule is excreted after 30 hours or passage to the colon of an intact patency capsule has been radiologically confirmed. Another disadvantage of video capsule endoscopy is that the quality of images is not comparable to the view achieved at conventional endoscopy with gas insufflation. In addition, it has been reported that the caecum is not reached in 8–40% of video capsule endoscopy studies [22, 29]. Finally, the most serious complication reported with video capsule

Device-assisted endoscopy is a generic term for any endoscopic technique that includes assisted progression (i.e. balloons and overtubes) and comprises doubleballoon enteroscopy, single-balloon enteroscopy and spiral enteroscopy [31]. Device-assisted endoscopy allows direct mucosal visualization of the entire small bowel as well as tissue sampling and therapeutic intervention (**Figure 3**). However, it is technically challenging and may require a bi-directional approach, deep seda-

Double-balloon enteroscopy was introduced in 2001 as the first method for device-assisted enteroscopy [32]. It allows deep intubation of the small bowel by pleating the bowel onto a long and flexible endoscope fitted with an overtube. The endoscope and the accompanying overtube have balloons at their distal end. By intermittent inflation and deflation of these two balloons, combined with instrument insertion and retraction, large portions of the small bowel can be visualized directly. Oral and anal routes are used to achieve a complete small bowel

Single-balloon enteroscopy is able to achieve a complete examination of the small bowel using principles similar to double-balloon enteroscopy. However, in contrast to double-balloon enteroscopy, this exam has only one balloon at the distal end of the overtube, which simplifies the preparation of the scope before starting the procedure. Single-balloon enteroscopy uses scope tip angulation and suction instead of balloon inflation to maintain a stable position while advancing the

Spiral enteroscopy is based on a completely different concept, by pleating of the bowel on the instrumentation shaft by active rotation instead of applying pushing force. The distal end of the overtube harbors a flexible spiral thread for pleating the small intestine over the overtube. By manually rotating the overtube, the spiral engages the small bowel which is thus pleated onto or unpleated from the overtube, respectively, depending on the direction of the spiral rotation. Spiral assisted endoscopy has been approved for both anterograde and retrograde enteroscopy. The Motorized Spiral Enteroscope is a new technology with an incorporated user-controlled motor contained in the handle of the endoscope [33]. This would offer the possibility to accelerate the procedure, facilitate insertion and simplify the technique with a single operator. Recently, Beyna et al. demonstrated that the Motorized Spiral Enteroscope is effective for diagnostic and therapeutic antegrade enteroscopy and may compare favorably with traditional methods of deep enteros-

endoscopy is perforation, which has been exceedingly rare [30].

*Endoscopy in Small Bowel Crohn's Disease DOI: http://dx.doi.org/10.5772/intechopen.95925*

*Endoscopy in Small Bowel Diseases*

**Parameter Score and descriptor**

A - Inflammation 0 - None

B – Extent of disease 0 – None

C - Stricture 0 – None

**Parameter Descriptor or** 

Villous appearance 0- Normal

Ulcers 0- Normal

Stenosis 0- None

*inflammation: Lewis score >790.*

Video capsule endoscopy may also identify a site for directed visualization with other endoscopic techniques. In fact, it can be complementary to device-assisted endoscopy since findings may help direct the most effective route of intubation (oral versus anal), in order to obtain a histopathological diagnosis or therapeutic

*Lewis score. Score total = worst-affected tertile villous appearance and ulcers plus stenosis score. Clinically insignificant inflammation: Lewis score <135, mild inflammation: Lewis score = 135–790, moderate to severe* 

1 – Mild to moderate (edema, hyperemia or denudation) 2 – Severe (edema, hyperemia or denudation) 3 – Bleeding, exudate, erosion aphthae, ulcers <0.5 cm

4 – Pseudopolyp, ulcers 0.5-2 cm

1 – Sigle segment (focal disease) 2–2-3 segments (patchy disease) 3 - >3 segments (diffuse disease)

3 – Obstruction (non-passage)

*Capsule endoscopy Crohn's disease activity index (CECDAI). CECDAI = proximal segment (A x B + C) +* 

**Longitudinal extent Descriptor**

1- Single 14- Patchy 17- Diffuse

9- < ¼ 12- ¼ - ½ 18- > ½

7- Transversed 10- Not transversed

8- Short-segment (<10%) 12- Long-segment (11–50%) 20- Whole tertile (>50%)

5- Short-segment (<10%) 10- Long-segment (11–50%) 15- Whole tertile (>50%)

2- Nonulcerated 24- Ulcerated

5 – Ulcers >2 cm

1 – Single-passed 2 – Multiple-passed

*distal segment (A x B+C). Clinical or endoscopic remission: CEDAI <4.*

**number**

3- Single 5- Few (2–7) 10- Multiple (≥8)

14- Single 20- Multiple

1- Edematous

In addition, video capsule endoscopy allows detection of subtle small bowel lesions, which may affect the therapeutic management. Because of the high sensitivity of video capsule endoscopy, it has a potential role in the assessment of mucosal healing after drug therapy and can be used in the follow-up of treated patients. In fact, video capsule endoscopy has a significant impact on disease management and is associated with earlier escalation of therapy. In the largest retrospective series of patients with established CD that were evaluated with video capsule endoscopy, a

The main advantage of video capsule endoscopy is the ability to visualize all of the small bowel with minimal discomfort for the patient. However, it lacks therapeutic capabilities and there is some risk of impaction due to possible strictures.

change in management was suggested in 40–52% of individuals [25, 26].

**32**

intervention.

**Table 4.**

**Table 3.**

The capsule retention rate in patients with suspected CD is 1.5–5.4% but can reach 13% in those with established CD, particularly if there are known intestinal stenosis [27, 28]. Therefore, those with obstructive symptoms or established CD of the small bowel should always have small bowel imaging and/or patency capsule evaluation before video capsule endoscopy to decrease the risk of capsule retention. Video capsule endoscopy is considered safe if the patency capsule is excreted before 30 hours, an intact capsule is excreted after 30 hours or passage to the colon of an intact patency capsule has been radiologically confirmed. Another disadvantage of video capsule endoscopy is that the quality of images is not comparable to the view achieved at conventional endoscopy with gas insufflation. In addition, it has been reported that the caecum is not reached in 8–40% of video capsule endoscopy studies [22, 29]. Finally, the most serious complication reported with video capsule endoscopy is perforation, which has been exceedingly rare [30].

#### **2.4 Device-assisted endoscopy**

Device-assisted endoscopy is a generic term for any endoscopic technique that includes assisted progression (i.e. balloons and overtubes) and comprises doubleballoon enteroscopy, single-balloon enteroscopy and spiral enteroscopy [31]. Device-assisted endoscopy allows direct mucosal visualization of the entire small bowel as well as tissue sampling and therapeutic intervention (**Figure 3**). However, it is technically challenging and may require a bi-directional approach, deep sedation or general anesthesia.

Double-balloon enteroscopy was introduced in 2001 as the first method for device-assisted enteroscopy [32]. It allows deep intubation of the small bowel by pleating the bowel onto a long and flexible endoscope fitted with an overtube. The endoscope and the accompanying overtube have balloons at their distal end. By intermittent inflation and deflation of these two balloons, combined with instrument insertion and retraction, large portions of the small bowel can be visualized directly. Oral and anal routes are used to achieve a complete small bowel examination.

Single-balloon enteroscopy is able to achieve a complete examination of the small bowel using principles similar to double-balloon enteroscopy. However, in contrast to double-balloon enteroscopy, this exam has only one balloon at the distal end of the overtube, which simplifies the preparation of the scope before starting the procedure. Single-balloon enteroscopy uses scope tip angulation and suction instead of balloon inflation to maintain a stable position while advancing the overtube.

Spiral enteroscopy is based on a completely different concept, by pleating of the bowel on the instrumentation shaft by active rotation instead of applying pushing force. The distal end of the overtube harbors a flexible spiral thread for pleating the small intestine over the overtube. By manually rotating the overtube, the spiral engages the small bowel which is thus pleated onto or unpleated from the overtube, respectively, depending on the direction of the spiral rotation. Spiral assisted endoscopy has been approved for both anterograde and retrograde enteroscopy.

The Motorized Spiral Enteroscope is a new technology with an incorporated user-controlled motor contained in the handle of the endoscope [33]. This would offer the possibility to accelerate the procedure, facilitate insertion and simplify the technique with a single operator. Recently, Beyna et al. demonstrated that the Motorized Spiral Enteroscope is effective for diagnostic and therapeutic antegrade enteroscopy and may compare favorably with traditional methods of deep enteroscopy in ease of use and procedural duration [34].

**Figure 3.**

*Device-assisted endoscopy images showing mucosal inflammation and ulcerations consistent with a diagnosis of Crohn's disease.*

Device-assisted endoscopy is not part of routine diagnostic testing in patients with suspected CD and should not be the first-line procedure in the evaluation of small bowel [1]. However, it may provide additional information when it is required biopsy of small bowel tissue to histological corroboration. Indeed, compared with video capsule endoscopy and small bowel imaging techniques, the advantages of device-assisted endoscopy include the evaluation of atypical lesions, the ability to obtain biopsies for histopathology and the potential for therapeutic intervention.

Device-assisted endoscopy studies in individuals with suspected CD have not included large numbers of patients but report a diagnostic yield as high as 80% [35]. In fact, device-assisted endoscopy is more sensitive in detecting lesions in patients with suspected CD than multiple radiographic imaging techniques. Nevertheless, because of the invasive and potentially time-consuming nature of the exam, it should be reserved for patients with high clinical suspicion of CD despite negative conventional studies (including ileocolonoscopy, video capsule endoscopy and radiographic imaging), particularly if endoscopic and histologic finding would alter disease management or potential therapeutic intervention is required [36]. In a prospective trial, positive findings at device-assisted enteroscopy led to a step-up of medical therapy in 74% of patients, leading to clinical remission in 88% [37]. In addition, device-assisted endoscopy may be preferable to video capsule endoscopy if there is a clinical suspicion of obstruction because it may allow therapeutic intervention and be safer, simply by avoiding capsule retention.

In patients with established CD, device-assisted endoscopy is indicated when endoscopic visualization and biopsies are necessary from areas of the small bowel inaccessible to conventional endoscopy [1]. Usually, previous video capsule endoscopy provides information on the optimal route of approach (oral or rectal) and lesion location. Adhesions may limit examination by device-assisted endoscopy and, in these circumstances, double-balloon enteroscopy may be preferred to single-balloon enteroscopy. In addition, device-assisted endoscopy has the capacity for endoscopic therapy, including dilation of small bowel strictures, removal of impacted capsules and treatment of bleeding lesions (*vide infra*).

Overall, diagnostic device-assisted endoscopy is safe, with few reports of complications (<1%) [38]. However, there appears to be an increased risk of complications in the case of active CD or previous intestinal surgery. The risk of perforation is 0.12% without therapeutic intervention and 1.74% with therapeutic intervention, the majority of which occurred after stricture dilatation [39]. Bleeding occurs in approximately 2.5%. In addition, device-assisted endoscopy involves risks related to sedation, in contrast to video capsule endoscopy where no sedation is required.

**35**

**Figure 4.**

*Endoscopy in Small Bowel Crohn's Disease DOI: http://dx.doi.org/10.5772/intechopen.95925*

**3.1 Treatment of intestinal strictures**

strictures will be more likely over time.

treated with medical therapy.

Strictures in CD develop during the course of the disease or as the presenting feature and are believed to result from partial healing and localized fibrosis. In addition, almost one-third of CD patients develop an anastomotic stricture after ileocecal resection/right hemicolectomy [40]. As a progressive disease, anastomotic

Immunomodulators and biologic agents have been widely used for the treatment of CD, however endoscopic dilatation is a preferred technique for the management of symptomatic and mild to moderate stenosing disease [41]. Indeed, medical therapy for stricture management is limited due to fibrotic nature. Endoscopic dilatation may prevent or delay the need for surgical resection or strictureplasty. Moreover, endoscopic balloon dilation should be performed to access the mucosa proximal to strictures and evaluate disease activity, that otherwise may be missed if we only relied on symptoms or biochemical markers [42]. Thus, it can provide

adequate endoscopic therapy and adjust or optimize medical therapy.

Endoscopic balloon dilation may be used in Crohn's strictures of the gastric outlet, duodenum, colon, ileocolonic anastomosis and of the small bowel, if accessible [43]. It is performed using a through-the-scope balloon catheter, which is a simple and safe procedure (**Figure 4**). The dilation procedure is performed with monitoring of the pressure of the inflated balloon using a dilator with or without X-ray guidance. When performing endoscopic balloon dilation, forcible dilation to achieve a larger dilation diameter or pressure is not recommended, as it could lead to intestinal perforation. The length of the balloons for inflation is about 5 cm; therefore, stenoses longer than 5 cm are considered unsuitable for endoscopic balloon dilation. Moreover, intestinal strictures with deep ulcers and fistulous complications are contraindications for endoscopic dilatation. In case of long or inflammatory strictures, balloon dilation may significantly increase the risk of perforation [44]. Hence, inflammatory and ulcerative strictures should be primarily

Over the last years, there is increasing evidence for endoscopic balloon dilation as a safe and minimally invasive effective method for the treatment of stricturing disease. In a retrospective single tertiary center study, Lopes et al. evaluated the long-term efficacy and safety of endoscopic balloon dilation in ileocolonic

*A segment of short stenosis is delineated using injection of contrast via a catheter (A). A guide wire is inserted* 

*through the stenosis and a balloon is then advanced over the wire and carefully inflated (B).*

**3. Treatment**
