**4.2 VCE in confirmed small bowel CD**

In patients with confirmed CD on ileo-colonoscopy, further small bowel evaluation is warranted irrespective of findings on ileo-colonoscopy (**Figure 2**). In this regard, dedicated small bowel cross sectional imaging (CTE/MRE) scores over VCE due to the ability to assess strictures, transmural involvement, intra-abdominal complications (abscess/fistula), extra-intestinal manifestations and anatomical distribution of the disease [2]. VCE is recommended subsequently if cross sectional imaging is non-contributory and if VCE findings could influence management. Small bowel CD only visible on VCE with normal cross sectional imaging is a new entity. A recent retrospective study have showed that it has a more favourable course compared to general CD with lower risk of complicated disease and requirement of step up therapy [15]. If VCE is indicated in confirmed CD, functional patency of the bowel should be confirmed with patency capsule given high rate of

**51**

*Role of Small Bowel Endoscopy in Diagnosis and Management of Inflammatory Bowel Disease…*

capsule retention in known CD (upto 13%) [2, 16]. In 27–40% cases, CTE/MRE finding suggestive of small bowel stricture may preclude VCE. However, not all strictures cause significant mechanical obstruction and patency capsule can be useful in this scenario [5]. The negative predictive value for ruling out a stricture is not different between patency capsule and non-enteroclysis small bowel radiologic

Meta-analysis by Dionisio et al. have shown that VCE was superior to small bowel follow through (SBFT)/small bowel enteroclysis (36%) and CTE (39%) with higher diagnostic yield (71%). In comparison, the diagnostic yield of VCE was inferior to MRE (79%) [18]. However, VCE is superior to CTE/MRE in diagnosing proximal small bowel lesions and detects small bowel lesions in 50% patients with previously diagnosed ileal CD [19]. VCE can also be considered when symptoms suggestive of small bowel disease (anaemia, malnutrition, pain abdomen) do not correlate with imaging findings. In a retrospective study, VCE led to a change in management in 45% cases in these settings [19]. VCE can be helpful in suspected flares of CD, where small bowel cross sectional imaging is normal [20]. Another indication of VCE is longitudinal follow up of small bowel CD to see for response to therapy such as mucosal healing [2]. Endoscopic mucosal healing has emerged as an important therapeutic target in CD as it can predict future relapses. In a prospective, observational cohort study from Israeli IBD Research Nucleus (IIRN) it was shown that VCE predicted both short and long term flare risk in patients with quiescent, asymptomatic CD. Increment in Lewis score was better than MRE global score [21]. Similarly, in a prospective study including paediatric CD patients, VCE based treat to target strategy significantly increased number of

Capsule retention in established CD can be treated with an observant, conservative trial of medical therapy using steroids and/or immunomodulators failing which endoscopic retrieval with DAE can be be attempted. Even in case of failure of endoscopic retrieval of retained capsule, most of the patients can be managed conservatively in the absence of obstructive symptoms [23]. Only a minority finally require surgery (**Figure 1B**). In a retrospective study of more than 2300 patients, among 301 CD patients (196 with confirmed small bowel involvement), 5 (1.6%) developed capsule retention but only 2 required surgical intervention [24].

Objective clinical activity scores are recommended to assess disease severity, small bowel involvement and response to medical therapy [2]. However, it should be borne in mind that these scores are for assessing type, location and severity of small bowel involvement but not for diagnosis of small bowel CD. For diagnosis of small bowel CD, Mow et al. proposed a cut off of more than 3 ulcers which is widely used for diagnosis of CD and has modest positive predictive value (PPV): 50–70% [25]. This however does not give any idea about location, severity and other inflammatory features such as edema and stenosis [2, 13]. There are two widely used validated scores to assess severity of small bowel CD on VCE: the Lewis score (LS) and the Capsule endoscopy Crohn's disease activity index (CECDAI) (**Tables 1** and **2**) [26, 27]. LS is based upon distribution and presence of ulcers (**Figure 3A, B**), villous edema and stenosis (**Figure 3C**). CECDAI evaluates severity of inflammation, extent of disease and stenosis. Among the two, CECDAI is simpler and was shown to be more reflective for active small bowel inflammation than LS in a comparative study [28]. There is strong correlation between LS and CECDAI but only moderate correlation with stool biomarkers such as faecal calprotectin [29]. A study showed that LS between 135–790

*DOI: http://dx.doi.org/10.5772/intechopen.96006*

examination according to a retrospective study [17].

patients achieving mucosal healing or deep remission [22].

**4.3 Role of VCE scores to evaluate CD**

was equivalent to 4.9–6.9 score in CECDAI [28].

#### *Role of Small Bowel Endoscopy in Diagnosis and Management of Inflammatory Bowel Disease… DOI: http://dx.doi.org/10.5772/intechopen.96006*

capsule retention in known CD (upto 13%) [2, 16]. In 27–40% cases, CTE/MRE finding suggestive of small bowel stricture may preclude VCE. However, not all strictures cause significant mechanical obstruction and patency capsule can be useful in this scenario [5]. The negative predictive value for ruling out a stricture is not different between patency capsule and non-enteroclysis small bowel radiologic examination according to a retrospective study [17].

Meta-analysis by Dionisio et al. have shown that VCE was superior to small bowel follow through (SBFT)/small bowel enteroclysis (36%) and CTE (39%) with higher diagnostic yield (71%). In comparison, the diagnostic yield of VCE was inferior to MRE (79%) [18]. However, VCE is superior to CTE/MRE in diagnosing proximal small bowel lesions and detects small bowel lesions in 50% patients with previously diagnosed ileal CD [19]. VCE can also be considered when symptoms suggestive of small bowel disease (anaemia, malnutrition, pain abdomen) do not correlate with imaging findings. In a retrospective study, VCE led to a change in management in 45% cases in these settings [19]. VCE can be helpful in suspected flares of CD, where small bowel cross sectional imaging is normal [20].

Another indication of VCE is longitudinal follow up of small bowel CD to see for response to therapy such as mucosal healing [2]. Endoscopic mucosal healing has emerged as an important therapeutic target in CD as it can predict future relapses. In a prospective, observational cohort study from Israeli IBD Research Nucleus (IIRN) it was shown that VCE predicted both short and long term flare risk in patients with quiescent, asymptomatic CD. Increment in Lewis score was better than MRE global score [21]. Similarly, in a prospective study including paediatric CD patients, VCE based treat to target strategy significantly increased number of patients achieving mucosal healing or deep remission [22].

Capsule retention in established CD can be treated with an observant, conservative trial of medical therapy using steroids and/or immunomodulators failing which endoscopic retrieval with DAE can be be attempted. Even in case of failure of endoscopic retrieval of retained capsule, most of the patients can be managed conservatively in the absence of obstructive symptoms [23]. Only a minority finally require surgery (**Figure 1B**). In a retrospective study of more than 2300 patients, among 301 CD patients (196 with confirmed small bowel involvement), 5 (1.6%) developed capsule retention but only 2 required surgical intervention [24].

#### **4.3 Role of VCE scores to evaluate CD**

Objective clinical activity scores are recommended to assess disease severity, small bowel involvement and response to medical therapy [2]. However, it should be borne in mind that these scores are for assessing type, location and severity of small bowel involvement but not for diagnosis of small bowel CD. For diagnosis of small bowel CD, Mow et al. proposed a cut off of more than 3 ulcers which is widely used for diagnosis of CD and has modest positive predictive value (PPV): 50–70% [25]. This however does not give any idea about location, severity and other inflammatory features such as edema and stenosis [2, 13]. There are two widely used validated scores to assess severity of small bowel CD on VCE: the Lewis score (LS) and the Capsule endoscopy Crohn's disease activity index (CECDAI) (**Tables 1** and **2**) [26, 27]. LS is based upon distribution and presence of ulcers (**Figure 3A, B**), villous edema and stenosis (**Figure 3C**). CECDAI evaluates severity of inflammation, extent of disease and stenosis. Among the two, CECDAI is simpler and was shown to be more reflective for active small bowel inflammation than LS in a comparative study [28]. There is strong correlation between LS and CECDAI but only moderate correlation with stool biomarkers such as faecal calprotectin [29]. A study showed that LS between 135–790 was equivalent to 4.9–6.9 score in CECDAI [28].

*Endoscopy in Small Bowel Diseases*

to lack of gold standard for CD diagnosis and non-specific nature of findings on VCE. The lesions detected in VCE can be due to other causes such as non-steroidal anti-inflammatory drugs (NSAIDs) use, cryptogenic multifocal ulcerated stenosing enteritis, intestine tuberculosis, lymphoma, small bowel malignancy and intestinal Behcet's disease. VCE findings like small mucosal breaks or erosions are seen in upto 20% of normal individuals. Hence, the positive predictive value (PPV) of VCE is dependent on the patient population and criteria for CD diagnosis in VCE [13]. Lewis score (LS) can be helpful in this regard. LS <135 signifies clinically non-significant lesion. LS > 135 detects significant small bowel lesion with 83.2% overall accuracy. LS between 135–790 is mild and > 790 indicates moderate to severe

*Algorithm for small bowel evaluation in a suspected or known case of Crohn's disease (CD). DAE- device assisted enteroscopy, MRE- magnetic resonance enteroclysis, CTE- computed tomography enteroclysis,* 

In patients with confirmed CD on ileo-colonoscopy, further small bowel evaluation is warranted irrespective of findings on ileo-colonoscopy (**Figure 2**). In this regard, dedicated small bowel cross sectional imaging (CTE/MRE) scores over VCE due to the ability to assess strictures, transmural involvement, intra-abdominal complications (abscess/fistula), extra-intestinal manifestations and anatomical distribution of the disease [2]. VCE is recommended subsequently if cross sectional imaging is non-contributory and if VCE findings could influence management. Small bowel CD only visible on VCE with normal cross sectional imaging is a new entity. A recent retrospective study have showed that it has a more favourable course compared to general CD with lower risk of complicated disease and requirement of step up therapy [15]. If VCE is indicated in confirmed CD, functional patency of the bowel should be confirmed with patency capsule given high rate of

**50**

disease [14].

**Figure 2.**

*VCE- video capsule endoscopy.*

**4.2 VCE in confirmed small bowel CD**


**Table 1.**

*The Lewis score for the assessment of small bowel lesions using small bowel capsule Endoscopy [26].*

In a retrospective study on patients with established CD, VCE led to treatment escalation in 45% patients. The indications of small bowel VCE were unexplained anaemia, discrepancy between symptoms and imaging, evaluation of full extent of CD to document mucosal healing [30]. Nevertheless, the risk of capsule retention even with normal cross sectional imaging study should be kept in mind in established CD prior to VCE and hence patency capsules are strongly recommended [12].

#### **4.4 Role of patency capsule**

Patency capsule use is strongly recommended in stablished CD prior to small bowel VCE to assess functional patency of small bowel. Patency capsule can be used selectively (in patients with symptoms of intestinal obstruction/history of intestinal obstruction or surgery/ patients with stricture on cross sectional imaging) or non-selectively (in all CD patients). A retrospective multi-center study have shown that the risk capsule retention was not significantly different with non-selective use (2.1%) compared to elective use (1.5%). But retention rate is as high as 11% after positive patency test [31].

**53**

*Role of Small Bowel Endoscopy in Diagnosis and Management of Inflammatory Bowel Disease…*

**CECDAI Proximal Distal**

Two types of patency capsules have been described: the Given patency capsule (M2A) and the Agile patency capsule. Agile capsule has two timer plugs compared to one timer plug in Given patency capsule. Agile capsule starts dissolving after 30 hours compared to 40–100 hours with Given patency capsule. Given capsule is composed of lactose whereas Agile capsule is composed of dissolvable components surrounding a small radio frequency identification tag which can be detectable by X ray [32, 33]. Rare cases of symptomatic intestinal occlusion have been reported with patency capsules [33, 34]. Agile capsule further reduces the risk of symptomatic intestinal obstruction. Hence, risk of symptomatic obstruction is minimal and patency capsules can be used safely. Most of the cases of abdominal pain due to obstruction is relieved by conservative measures with only a small minority requir-

*The capsule endoscopy Crohn's disease activity index (CECDAI) for the assessment of small bowel lesions using* 

Given unclear benefit of non-selective use of patency capsules in CD and high risk of capsule retention in CD, the use of patency capsule should be based on

Intestinal resection is eventually required in upto three fourth of CD patients after 20 years of disease [36]. Postoperative recurrence after ileo-colonic resection can occur in upto 70% patients after 20 years post surgery. Ileal lesions can be scored by Rutgreet's score at the first ileocolonoscopy (ideally at 6 months postoperatively) which help to predict post operative recurrence: i0, no lesions: i1—less

clinical history, imaging finding, clinician's discretion and availability.

ing endoscopic or surgical intervention [33, 35].

**4.5 Assessment of postoperative CD recurrence**

*DOI: http://dx.doi.org/10.5772/intechopen.96006*

1 = Mild to moderate edema/hyperemia/denudation

3 = Bleeding, exudate, aphthae, erosion, small ulcer (≥ 0.5 cm)

2 = Severe edema/hyperemia/denudation

4 = Moderate ulcer (0.5–2 cm), pseudopolyp

**CECDAI Scoring System**

**A. Inflammation score**

5 = Large ulcer (2 cm) **B. Extent of disease score**

3 = Diffuse disease **C. Narrowing (stricture)**

1 = Focal disease (single segment) 2 = Patchy disease (multiple segments)

**Segmental score = A × B + C**

*small bowel capsule Endoscopy [27].*

**Total score = (A1 × B1 + C1) + (A2 × B2 + C2)**

0 = None

0 = None

0 = None 1 = Single-passed 2 = Multiple-passed

**Table 2.**

*Role of Small Bowel Endoscopy in Diagnosis and Management of Inflammatory Bowel Disease… DOI: http://dx.doi.org/10.5772/intechopen.96006*


#### **Table 2.**

*Endoscopy in Small Bowel Diseases*

**Villous appearance** Normal - 0

**Ulcer** None-0

**Villous appearance** Normal - 0

**Ulcer** None-0

**Stenosis (rated for the whole** 

**First tertile**

**Second tertile**

**Third tertile**

**study)**

**Table 1.**

In a retrospective study on patients with established CD, VCE led to treatment escalation in 45% patients. The indications of small bowel VCE were unexplained anaemia, discrepancy between symptoms and imaging, evaluation of full extent of CD to document mucosal healing [30]. Nevertheless, the risk of capsule retention even with normal cross sectional imaging study should be kept in mind in established CD prior to VCE and hence patency capsules are strongly recommended [12].

**Stenosis** None-0 Ulcerated - 24 Traversed - 7

**Parameters Number Longitudinal extent Descriptors**

**Villous appearance** Normal - 0 Short segment - 8 Single - 1

**Ulcer** None-0 Short segment - 5 <1/4–9

Short segment - 8 Long segment - 12 Whole tertile - 20

> Short segment - 5 Longsegment-10 Whole tertile - 15

Edematous - 1 Long segment - 12 Patchy −14

Single - 3 Long segment - 10 1/4–1/2–12 Few-5 Whole tertile - 15 >1/2–18

> Short segment - 8 Long segment - 12 Whole tertile - 20

> > Short segment - 5 Longsegment-10 Whole tertile - 15

Single −14 Non-ulcerated - 2 Not traversed - 10

Whole tertile - 20 Diffuse - 17

Single - 1 Patchy −14 Diffuse −17

< 1/4–9 1/4–1/2–12 >1/2–18

Single - 1 Patchy −14 Diffuse −17

< 1/4–9 1/4–1/2–12 >1/2–18

Edematous - 1

Single-3 Few-5 Multiple - 10

Multiple - 10

Edematous - 1

Single-3 Few-5 Multiple - 10

Multiple - 20

*The Lewis score for the assessment of small bowel lesions using small bowel capsule Endoscopy [26].*

Patency capsule use is strongly recommended in stablished CD prior to small bowel VCE to assess functional patency of small bowel. Patency capsule can be used selectively (in patients with symptoms of intestinal obstruction/history of intestinal obstruction or surgery/ patients with stricture on cross sectional imaging) or non-selectively (in all CD patients). A retrospective multi-center study have shown that the risk capsule retention was not significantly different with non-selective use (2.1%) compared to elective use (1.5%). But retention rate is as high as 11% after

**52**

**4.4 Role of patency capsule**

positive patency test [31].

*The capsule endoscopy Crohn's disease activity index (CECDAI) for the assessment of small bowel lesions using small bowel capsule Endoscopy [27].*

Two types of patency capsules have been described: the Given patency capsule (M2A) and the Agile patency capsule. Agile capsule has two timer plugs compared to one timer plug in Given patency capsule. Agile capsule starts dissolving after 30 hours compared to 40–100 hours with Given patency capsule. Given capsule is composed of lactose whereas Agile capsule is composed of dissolvable components surrounding a small radio frequency identification tag which can be detectable by X ray [32, 33]. Rare cases of symptomatic intestinal occlusion have been reported with patency capsules [33, 34]. Agile capsule further reduces the risk of symptomatic intestinal obstruction. Hence, risk of symptomatic obstruction is minimal and patency capsules can be used safely. Most of the cases of abdominal pain due to obstruction is relieved by conservative measures with only a small minority requiring endoscopic or surgical intervention [33, 35].

Given unclear benefit of non-selective use of patency capsules in CD and high risk of capsule retention in CD, the use of patency capsule should be based on clinical history, imaging finding, clinician's discretion and availability.

#### **4.5 Assessment of postoperative CD recurrence**

Intestinal resection is eventually required in upto three fourth of CD patients after 20 years of disease [36]. Postoperative recurrence after ileo-colonic resection can occur in upto 70% patients after 20 years post surgery. Ileal lesions can be scored by Rutgreet's score at the first ileocolonoscopy (ideally at 6 months postoperatively) which help to predict post operative recurrence: i0, no lesions: i1—less

#### **Figure 3.**

*Small bowel capsule endoscopy (A-C) and enteroscopy (D-F) in Crohn's disease (CD). A and B showing ulcers in CD, C. ulcerated stricture in CD, D. large deep ulcer in CD on device assisted enteroscopy (DAE), E. tight inflammatory stricture in CD, F. mildly inflamed stricture in CD on DAE.*

#### **Figure 4.**

*Post-operative recurrence of Crohn's disease (CD) (A-B) and endoscopic management of CD strictures. A. Ileal recurrence of CD on ileoscopy. B. Anastomotic site recurrence of CD after ileo-cecal resection in CD seen on colonoscopy. C. Inflammatory stricture in CD- not ideal for endoscopic dilatation, D and E- mild or non- inflammatory fibrotic stricture - ideal for endoscopic dilatation, F. endoscopic balloon dilatation being performed in CD stricture.*

than 5 aphthous lesions: i2- >5 aphthous lesions with normal mucosa between the lesions, or skip areas of larger lesions or lesions confined to the ileocolonic anastomosis (i.e., <1 cm in length); i3-diffuse aphthous ileitis with diffusely inflamed mucosa; i,4-diffuse inflammation with larger ulcers, nodules, and/or narrowing.

**55**

*Role of Small Bowel Endoscopy in Diagnosis and Management of Inflammatory Bowel Disease…*

Apart from prediction of post operative recurrence, treatment can be decided based

Ileo-colonoscopy is the standard test to diagnose post operative recurrence of CD (**Figure 4A, B**), but emerging data shows that VCE can diagnose CD recurrence in significantly higher number of patients compared to ileo-colonoscopy and can lead to change in management in more than half of the patients [38–40]. A recent study has shown that ileal rather than anastomotic recurrence is more likely to predict long term outcomes in CD (**Figure 4A, B**) [41]. Hence, VCE has the potential to improve clinical outcomes in postoperative CD beyond the scope of

VCE in IBD-U can detect new small bowel lesions compatible with CD in 17–70% patients. However, a normal VCE can not preclude the future evolution of new small bowel lesions suggestive of CD [42, 43]. In a study 5/25 (20%) IBD- U patients with normal VCE developed CD on follow up [44]. This is particularly important in paediatric IBD. Additional information provided by VCE can impact

The drawbacks of VCE like lack of therapeutic ability, low specificity and inability to perform histological confirmation are circumvented by DAE. DAE includes double balloon enteroscopy (DBE), single balloon enteroscopy (SBE), balloon guided enteroscopy (BGE) and spiral enteroscopy. The detailed technical

SBE, in contrast to DBE does not have any balloon at the tip of the enteroscope and hence handling of the balloon control unit is easier. DBE may be preferred over SBE in the presence of adhesions. Additionally, during retrograde DAE, which is technically more difficult than antegrade DAE, SBE may be more prone to backward slippage compared to DBE due to lack of balloon at the

A novel through the scope (TTS), on-demand balloon assisted enteroscopy have been recently described which can be performed by push and pull technique by a disposable advancing balloon through the working channel of a colonoscope with a minimal working channel diameter of 3.7 mm. The advantage of this technique is feasibility, safety and shorter procedure duration without adverse events. The learning curve is also smaller as compared to other DAE techniques. The main drawback of this procedure is sub-optimal stability of endoscope during therapeutic procedures due to lack of aching balloon. This has been recently overcome by using a colonoscope with an integrated latex free balloon at the bending section. In a multi-centre study in adults, the average insertion length were 158 cm (50–350 cm) and 89 cm (20–150 cm) from antegrade and retrograde approach respectively, with an average procedure time of 15.5 minutes [47]. More recently, the feasibility and safety of this NaviAid AB device (Smart Medical Systems Ltd., Ra'anana, Israel) has

aspects of all DAE techniques are out of the scope of the current chapter.

*DOI: http://dx.doi.org/10.5772/intechopen.96006*

ileo-colonoscopy.

upon the scoring system for recurrent CD [37].

**4.6 Assessment of IBD-unclassified (IBD-U)**

management in this scenario [45].

**5. Enteroscopy in IBD**

**5.1 SBE/DBE**

**5.2 BGE**

enteroscope tip [46].

*Role of Small Bowel Endoscopy in Diagnosis and Management of Inflammatory Bowel Disease… DOI: http://dx.doi.org/10.5772/intechopen.96006*

Apart from prediction of post operative recurrence, treatment can be decided based upon the scoring system for recurrent CD [37].

Ileo-colonoscopy is the standard test to diagnose post operative recurrence of CD (**Figure 4A, B**), but emerging data shows that VCE can diagnose CD recurrence in significantly higher number of patients compared to ileo-colonoscopy and can lead to change in management in more than half of the patients [38–40]. A recent study has shown that ileal rather than anastomotic recurrence is more likely to predict long term outcomes in CD (**Figure 4A, B**) [41]. Hence, VCE has the potential to improve clinical outcomes in postoperative CD beyond the scope of ileo-colonoscopy.

#### **4.6 Assessment of IBD-unclassified (IBD-U)**

VCE in IBD-U can detect new small bowel lesions compatible with CD in 17–70% patients. However, a normal VCE can not preclude the future evolution of new small bowel lesions suggestive of CD [42, 43]. In a study 5/25 (20%) IBD- U patients with normal VCE developed CD on follow up [44]. This is particularly important in paediatric IBD. Additional information provided by VCE can impact management in this scenario [45].

### **5. Enteroscopy in IBD**

The drawbacks of VCE like lack of therapeutic ability, low specificity and inability to perform histological confirmation are circumvented by DAE. DAE includes double balloon enteroscopy (DBE), single balloon enteroscopy (SBE), balloon guided enteroscopy (BGE) and spiral enteroscopy. The detailed technical aspects of all DAE techniques are out of the scope of the current chapter.

#### **5.1 SBE/DBE**

*Endoscopy in Small Bowel Diseases*

**54**

**Figure 4.**

*performed in CD stricture.*

**Figure 3.**

than 5 aphthous lesions: i2- >5 aphthous lesions with normal mucosa between the lesions, or skip areas of larger lesions or lesions confined to the ileocolonic anastomosis (i.e., <1 cm in length); i3-diffuse aphthous ileitis with diffusely inflamed mucosa; i,4-diffuse inflammation with larger ulcers, nodules, and/or narrowing.

*Post-operative recurrence of Crohn's disease (CD) (A-B) and endoscopic management of CD strictures. A. Ileal recurrence of CD on ileoscopy. B. Anastomotic site recurrence of CD after ileo-cecal resection in CD seen on colonoscopy. C. Inflammatory stricture in CD- not ideal for endoscopic dilatation, D and E- mild or non- inflammatory fibrotic stricture - ideal for endoscopic dilatation, F. endoscopic balloon dilatation being* 

*Small bowel capsule endoscopy (A-C) and enteroscopy (D-F) in Crohn's disease (CD). A and B showing ulcers in CD, C. ulcerated stricture in CD, D. large deep ulcer in CD on device assisted enteroscopy (DAE), E. tight* 

*inflammatory stricture in CD, F. mildly inflamed stricture in CD on DAE.*

SBE, in contrast to DBE does not have any balloon at the tip of the enteroscope and hence handling of the balloon control unit is easier. DBE may be preferred over SBE in the presence of adhesions. Additionally, during retrograde DAE, which is technically more difficult than antegrade DAE, SBE may be more prone to backward slippage compared to DBE due to lack of balloon at the enteroscope tip [46].

#### **5.2 BGE**

A novel through the scope (TTS), on-demand balloon assisted enteroscopy have been recently described which can be performed by push and pull technique by a disposable advancing balloon through the working channel of a colonoscope with a minimal working channel diameter of 3.7 mm. The advantage of this technique is feasibility, safety and shorter procedure duration without adverse events. The learning curve is also smaller as compared to other DAE techniques. The main drawback of this procedure is sub-optimal stability of endoscope during therapeutic procedures due to lack of aching balloon. This has been recently overcome by using a colonoscope with an integrated latex free balloon at the bending section. In a multi-centre study in adults, the average insertion length were 158 cm (50–350 cm) and 89 cm (20–150 cm) from antegrade and retrograde approach respectively, with an average procedure time of 15.5 minutes [47]. More recently, the feasibility and safety of this NaviAid AB device (Smart Medical Systems Ltd., Ra'anana, Israel) has been shown in paediatric population [48]. Therapeutic interventions can be performed after removing the balloon catheter. This novel technique obviates the need for a enteroscope and setting up of over-tube balloons.

#### **5.3 SE/NMSE**

Spiral enteroscopy(SE) involves the use of over-tube with raised spiral edges which is rotated clockwise for advancement of enteroscope pleating small bowel loops. The over-tube has been now been replaced by novel motorised spiral enteroscopy (NMSE) composed of a reusable endoscope with integrated motor permitting rotation of a short spiral over-tube in the insertion tube portion of the endoscope and a motor control unit. The motor control unit is composed of a foot pedal and visual force gauge. The advantages of NMSE are shorter procedure time, relative ease of use, high diagnostic yield (>80%), higher total enteroscopy rates (>60%) [49–51]. Therapeutic interventions like stricture dilatation and retrieval of retained capsule endoscope have been described with NMSE [52]. Due to large diameter of overture in NMSE, it is not suitable for use in children.

#### **5.4 Indications of DAE in CD**

DAE in CD is indicated particularly in suspected isolated small bowel CD in whom ileo-colonoscopy/ small bowel cross sectional imaging are inconclusive and histological diagnosis can alter patient management (**Figure 3D**-**F**). In patients with established CD, DAE can diagnose and treat stenotic complications (**Figure 4C**-**F**), assess mucosal healing for adjusting medical therapy and precisely locate lesions to direct targeted resection (**Figure 2**) [9].

DAE in suspected and established CD is done for diagnostic and therapeutic intent respectively. In suspected CD, DAE is performed to confirm CD beyond the reach of endoscopy and ileo-colonoscopy by obtaining biopsy and thus excluding alternative diagnosis like tuberculosis and small bowel malignancy. The diagnostic yield ranges between 22–70% in suspected CD.

#### *5.4.1 Diagnostic DAE*

Diagnostic yield is particularly higher if DAE is preceded by other small bowel investigations like CTE/MRE/VCE which help to identify the lesion and guide insertion route (oral or rectal). Total enteroscopy rates in this setting ranges from 20–80% [53, 54]. Diagnostic yield of DAE is comparable to VCE according to two meta-analysis which concluded that VCE should be considered first due to noninvasive nature [55, 56]. But, histological confirmation can not be obtained by VCE which is important in areas where infections (like tuberculosis) predominate. It should be borne in mind that DAE is technically challenging specially in the presence of adhesions, associated with higher rates of complications (0.72% major complications rate, 10 times higher perforation rate compared to colonoscopy) in CD and requires deep sedation/general anaesthesia [57, 58]. Perforation risk is higher in patients with active CD, altered anatomy and anastomotic ulcerations [58]. Hence, DAE should be performed only if the findings can alter therapeutic management. In a prospective study, DAE led to step up in therapy in three forth of CD patients leading to clinical remission in nearly 90% patients [59].

Most of the studies on DAE in CD patients has been done with SBE or DBE. The diagnostic yield (**Table 3**) of DAE in suspected and known CD are 27%–79% and 53%–87% respectively. The agreement between small bowel imaging and DAE is higher in patients with known CD (75.6%) compared to those with suspected CD

**57**

**Author** **Broide et al, 2020** **Holleran et al, 2018** **Tun et al, 2016** **Christian et al, 2016**

**Rahman et al, 2015** **Navaneethan et al, 2014**

**Schulz et al,** 

DBE

Adult CD

Retrospective

16

0

69

**2014**

**Urs et al, 2014**

**Uchida et** 

DBE

Paediatric

Prospective

8

4

CD

**al,2012**

**De Riddler et al,** 

SBE

Paediatric

Prospective

14

6

CD

**2012**

**Di Nardo, 2012**

**Möschler et al,** 

DBE

Adult CD

Prospective

193

47

**2011**

**Kondo et al,** 

DBE

Adult CD

Retrospective

25

50

47

53

**2010**

SBE

Paediatric

Prospective

16

14

CD

DBE

Paediatric

Prospective

3

5

66 75 57 87

64

83

75

100

CD

SBE or DBE

Adult CD

Retrospective

22

43

27

53

DBE

Adult CD

Retrospective

43

38

79

87

77

82 53

Retrograde SBE

DBE

Adult CD Adult CD

Retrospective

29

41.4

Retrospective

100

0

SBE

Adult CD

Retrospective

13

39

39

77

69

BGE

Paediatric IBD

Prospective

15 (IBD)

16 (IBD)

**DAE system**

**Patient subgroup**

**Study design**

**Suspected CD (n)**

**Known CD (n)**

**Diagnostic yield suspected CD (%)**

**Diagnostic yield confirmed CD (%)**

**Impact on management: suspected CD (%)**

**Impact on management: confirmed CD (%)**

*Role of Small Bowel Endoscopy in Diagnosis and Management of Inflammatory Bowel Disease…*

*DOI: http://dx.doi.org/10.5772/intechopen.96006*

45

> 17


*Role of Small Bowel Endoscopy in Diagnosis and Management of Inflammatory Bowel Disease… DOI: http://dx.doi.org/10.5772/intechopen.96006*

*Endoscopy in Small Bowel Diseases*

**5.4 Indications of DAE in CD**

*5.4.1 Diagnostic DAE*

direct targeted resection (**Figure 2**) [9].

yield ranges between 22–70% in suspected CD.

leading to clinical remission in nearly 90% patients [59].

**5.3 SE/NMSE**

been shown in paediatric population [48]. Therapeutic interventions can be performed after removing the balloon catheter. This novel technique obviates the need

Spiral enteroscopy(SE) involves the use of over-tube with raised spiral edges which is rotated clockwise for advancement of enteroscope pleating small bowel loops. The over-tube has been now been replaced by novel motorised spiral enteroscopy (NMSE) composed of a reusable endoscope with integrated motor permitting rotation of a short spiral over-tube in the insertion tube portion of the endoscope and a motor control unit. The motor control unit is composed of a foot pedal and visual force gauge. The advantages of NMSE are shorter procedure time, relative ease of use, high diagnostic yield (>80%), higher total enteroscopy rates (>60%) [49–51]. Therapeutic interventions like stricture dilatation and retrieval of retained capsule endoscope have been described with NMSE [52]. Due to large diameter of

DAE in CD is indicated particularly in suspected isolated small bowel CD in whom ileo-colonoscopy/ small bowel cross sectional imaging are inconclusive and histological diagnosis can alter patient management (**Figure 3D**-**F**). In patients with established CD, DAE can diagnose and treat stenotic complications (**Figure 4C**-**F**), assess mucosal healing for adjusting medical therapy and precisely locate lesions to

DAE in suspected and established CD is done for diagnostic and therapeutic intent respectively. In suspected CD, DAE is performed to confirm CD beyond the reach of endoscopy and ileo-colonoscopy by obtaining biopsy and thus excluding alternative diagnosis like tuberculosis and small bowel malignancy. The diagnostic

Diagnostic yield is particularly higher if DAE is preceded by other small bowel investigations like CTE/MRE/VCE which help to identify the lesion and guide insertion route (oral or rectal). Total enteroscopy rates in this setting ranges from 20–80% [53, 54]. Diagnostic yield of DAE is comparable to VCE according to two meta-analysis which concluded that VCE should be considered first due to noninvasive nature [55, 56]. But, histological confirmation can not be obtained by VCE which is important in areas where infections (like tuberculosis) predominate. It should be borne in mind that DAE is technically challenging specially in the presence of adhesions, associated with higher rates of complications (0.72% major complications rate, 10 times higher perforation rate compared to colonoscopy) in CD and requires deep sedation/general anaesthesia [57, 58]. Perforation risk is higher in patients with active CD, altered anatomy and anastomotic ulcerations [58]. Hence, DAE should be performed only if the findings can alter therapeutic management. In a prospective study, DAE led to step up in therapy in three forth of CD patients

Most of the studies on DAE in CD patients has been done with SBE or DBE. The diagnostic yield (**Table 3**) of DAE in suspected and known CD are 27%–79% and 53%–87% respectively. The agreement between small bowel imaging and DAE is higher in patients with known CD (75.6%) compared to those with suspected CD

for a enteroscope and setting up of over-tube balloons.

overture in NMSE, it is not suitable for use in children.

**56**

