Vascular lesions
Angiodysplasia
Dieulafoy lesion
Ischemic enteritis
Varices
Portal enteropathy
Aortoenteric fistula
Phlebectasia
Telangiectasia (Osler-Rendu-Weber disease, Turner’s syndrome, systemic sclerosis)
Hemangioma (blue rubber bleb nevus syndrome, Klippel-Trenaunay-Weber syndrome)
Inflammatory lesions
Nonsteroidal anti-inflammatory drug (NSAID)-induced enteropathy
Crohn’s disease
Celiac disease (ulcerative jejunitis)
Vasculitis/ Behcet’s disease
Amyloidosis
Radiation enteritis
Eosinophilic enteritis
Anastomotic ulcer
Nonspecific ulcer
Polypoid lesions
Inflammatory polyp
Lipoma
Hamartoma
Adenomyoma
Lymphangioma
Peutz-Jeghers syndrome
Cronkhite-Canada syndrome
Gardner’s syndrome
Neoplastic lesions
Gastrointestinal stromal tumor (GIST)
Adenoma
Adenocarcinoma
Leiomyosarcoma
MALT lymphoma
Follicular lymphoma
T-cell lymphoma
Neuroendocrine tumor (carcinoid)
Metastasis (melanoma, breast, renal cell)
Diverticulosis
Meckel’s diverticulum
Small bowel diverticulosis
Diverticula retracted by tumors
Diverticula retracted by adhesions
Other lesions
Intestinal intussusception
Whipple’s disease
Strongyloidiasis
Cytomegalovirus
Mycobacterium tuberculosis
Mycobacterium avium complex
Blastomycosis
Fig. 14.1
The most common causes of small bowel bleeding are arteriovenous malformations (AVMS). These can be single (a) or multiple (b). Even small AVMs can result in significant bleeding. Water immersion endoscopy is of particular use to visualize active bleeding, as the blood will spurt into the water (c)
Fig. 14.2
Blood clots and fresh blood may obscure the field of view (a). During device-assisted enteroscopy, the lumen can be cleansed using water flushed through the accessory channel of the scope. In this case, argon plasma coagulation is applied to a bleeding AVM (b, c)
Fig. 14.3
Dieulafoy lesions often cause massive overt obscure GI bleeding. Part A shows large amount of fresh blood clots in a patient with Dieulafoy lesion (a). In this case the lesion was treated using combination therapy starting with injection (b, c). The lesion was first injected with saline-epinephrine mixture (1:20,000) and then cauterized with argon plasma coagulation
Fig. 14.4
Ulcers with visible vessels are found occasionally in patients with overt or occult OGIB
Fig. 14.5
Small bowel polyps and tumors are an important cause for both occult and overt OGIB. The tumors include, but are not limited to, carcinoma (a), gastrointestinal stromal tumor (GIST) (b, c), neuroendocrine tumors (NET) (d, e) and lipomas (f). GIST and NET are most commonly submucosal lesions, often missed by capsule endoscopy
Fig. 14.6
An uncommon but important lesion resulting in OGIB found during retrograde deep enteroscopy is Meckel’s diverticulum (a, b). The ulcers on the diverticulum’s edge are often subtle and can be easily missed (arrows)
Enteroscopic Diagnosis and Accessories for Small Bowel Bleeding
The preferred endoscopic methods to investigate small bowel bleeding include capsule endoscopy (CE) and device-assisted enteroscopy (DAE) [1, 2, 8]. CE does not allow for therapeutic interventions, but is a useful test to screen for causes of OGIB [8]. DAE includes overtube-assisted enteroscopy, balloon-assisted enteroscopy (BAE), and spiral enteroscopy [5, 7–9]. Whereas traditional push enteroscopy allows for the investigation of the proximal third of the small bowel, DAE enables deeper assessment of the small bowel (deep enteroscopy), including the potential for total examination of the small intestine (complete enteroscopy) [2–9]. Deep enteroscopy has significantly increased our ability to treat and palliate small intestinal bleeding (Table 14.2) [3, 6, 8, 10–23].
Table 14.2
Long-term outcomes of patients with GI bleeding treated using balloon-assisted enteroscopy
Author (reference number) | Year | Number of patients | Diagnostic yield | Patients with AVM | Endoscopic treatment | Follow-up months (range) | Overall re-bleeding rate |
---|---|---|---|---|---|---|---|
Samaha [10] | 2012 | 261 | 51 % | 129 | 129 | 22 (1–52) | 46 % |
May [11] | 2011 | 63 | NR | 44 | 44 | 55 | 42 % |
Fujita [12] | 2010 | 87 | 46 % | NR | 21 | 41 (2–66) | 44.8 % |
Shinozaki [13] | 2010 | 200 | 77 % | 29 | 25 | 30 (6–78) | 39 % |
Gerson [14] | 2009 | 85 | NR | 43 % | 30 (19–51) | 40 % | |
Arakawa [15] | 2009 | 162 | 64 % | 26 | 19 | 18.5 | 31 % |
Hindryckx [16] | 2008 | n/a | n/a | 18 | 10 | 21 | 38 % |
Albert [17] | 2008 | n/a | n/a | 112 | 36 | 20.7 | 31 % |
Madisch [18] | 2008 | 124 | 49 % | n/a | n/a | 18 % | |
Ohmiya [20] | 2007 | 479 | 58 % | 63 | 63 | 55 | 42 % |
Hsu [21] | 2007 | 20 | 75 % | n/a | n/a | 35 % | |
Sun [22] | 2007 | 152 | 75 % | n/a | n/a | 16 | 12 % |
Important differences in endoscopic approach, however, exist when treating small bowel bleeding relative to other parts of the luminal GI tract:
1.
The small bowel is long and has many loops, often making it more difficult to obtain a good endoscopic position to target the lesion of interest. Thus, advanced endoscopic skills are needed to maneuver the enteroscope within the tortuous and long small bowel.
2.
The small bowel wall is very thin. Therefore, particular attention should be given when applying noncontact or contact thermal therapies, such as argon plasma or bipolar coagulation.
3.
The utilization of available hemostatic devices during deep enteroscopy for small bowel bleeding can be challenging, in part due to difficult instrument passage through the long working channel of the enteroscope. The endoscopist should be familiar with the advantages and limitations of particular hemostatic devices, such as clip placement, contact coagulation, and argon plasma coagulation, in the context of deep enteroscopy (Table 14.3).
Table 14.3
Endoscopic hemostatic techniques for small bowel bleeding
Thermal therapy | Argon plasma coagulation |
Electrocoagulation | |
Monopolar | |
Bipolar/Multipolar | |
Heater probe | |
Injection therapy | Epinephrine |
Fibrin glue/thrombin | |
Cyanoacrylate | |
Mechanical | Endoscopic clips |
Detachable snare (endoloop) |
Technical Details of Enteroscopes and Devices Used for Therapeutic Enteroscopy
Knowledge of the technical details of the deep enteroscopes and accessories available are mandatory when planning endoscopic hemostasis (Tables 14.4 and 14.5) [5, 8, 25]. The spiral overtube is no longer available on a commercial basis and will not be detailed any further. A key difference as regards therapeutic enteroscopy is the need for longer and smaller caliber devices, which can be advanced through the working channel of the enteroscope. The enteroscopes are long and the diameters of their working channels are similar or smaller than that of a diagnostic upper endoscope (Table 14.5). Based on the type of deep enteroscope utilized, proper selection and familiarity with particular hemostatic devices become important. The staff should be well trained in maneuvers related to deep enteroscopy, such as handling of the balloon overtube, as well as devices utilized during the procedure. In addition, the endoscopist treating midgut bleeding should be experienced in small bowel therapeutic endoscopy.
Table 14.4
Selected hemostatic tools available for use during deep enteroscopy