Therapeutic Possibilities with DBE: A Focus on Accessories

Hemostasis 

Argon plasma coagulation (APC) 

Small bleeding lesions, such as angiodysplasias or minor ulcers, may be treated by local heat application. Both available enteroscopes (Fujinon), the EN-450P5 with a 2.2-mm working channel and the EN-450T5 with a 2.8-mm channel, allow the use of a specially developed argon plasma probe (Fig. 1). To facilitate advancement of this probe, particularly through the diagnostic enteroscope (P5), we use medium chain triglycerides (MCT) as a lubricant.

Table 1. Accessories for Treating Small Bowel Pathology

			Usable for Channel Size:
	Procedure/Type of Accessory	Company, Article No.	2.2 mm EN-450P5	2.8 mm EN-450T5
	1. Hemostasis
	Argon coagulation probes	eg, ERBE 20132-212	x	x
		eg, ERBE 20132-166		x
		or ERBE 20132-179 (multiple use)
	Lubricant	Fresenius Kabi MCT oil	x	x
	Injection needle	Fujinon F2EZTV1805250HP-S
		Medwork 500753	x	x
	Epinephrine	1:20,000 dilution	x	x
	Fibrin glue	Various providers	x	x
	Metal clip	Boston Scientific Resolution Clip 22612		x
		Olympus Quick Clip HX-201UR-135
	Hot biopsy forceps	Fujinon F6HOPK2304250X		x
	2. Polypectomy
	Snares	Recommendation: Ø15 mm, eg:	x	x
		- Fujinon F4E0PK1815250MP-S
		- MTW S052011212
		Combined Ø 15 mm/Ø 30 mm:
		- Medwork 501844
	Retrieval basket	Fujinon ROT-E45-25-350-EIN	x	x
	Polyp retriever	Fujinon F7GZEW1835250C-S	x	x
		Medwork 500618
	3. Treatment of stenoses
	Stepwise inflatable balloons	Boston Scientific CRE TTS balloons 6-8		x
		mm (No. 5845), 8-10 mm (No. 5846), 10-12
		mm (No. 5847), 12-15 mm (No. 5848)
	Guidewire	Fujinon F3LQPK 0850650X-S (650 cm)	x	x
	4. Retrieval of foreign bodies
	Snares	See polypectomy	x	x
	Metal basket	Fujinon F1NSEW1825250Z-S	x	x
	5. Tattooing
	Injection needle	Fujinon F2EZTV1805250HP-S
		Medwork 500753	x	x
	Sterile ink	Spot Ink, GI Supply	x	x

View Large Image Download to PowerPoint

Figure 1. Application of argon plasma coagulation in a patient with multiple angiodysplasias. (A) Before coagulation. (B) After coagulation. (Color version of figure is available at www.techgiendoscopy.com.)

In our experience, it may be advisable to treat small angiodysplasias during the insertion of the scope in the yet untouched small bowel, since during retraction minor iatrogenic lesions caused by propulsion of the instrument are difficult to differentiate from genuine hemorrhagic lesions.

Because the wall of the small bowel is quite thin and perforations may occur,1, 9 low-level coagulation settings should be chosen to produce coagulation confined to the superficial layers. For the choice of mode and the power settings, it is advisable to adhere to the manufacturer’s recommendations. For example, using the ERBE Vio APC 2 generator it is recommended to use either the “Precise” mode (effect “E4” or “E5”), which allows a constant depth of coagulation within a range of 1 to 5 mm distance between the probe and the small bowel wall, or the “Pulsed” mode or “Forced” mode at 20 W to 30 W. The “Pulsed” APC (effect 1 or 2) is particularly useful in patients with multiple angiodysplasias, because it causes reliable ignition at a distance up to 5 mm. As in APC of the right colon, the tip of the APC probe should not touch the bowel wall, because gas blebs or even perforations may occur, and the application duration should be confined to a maximum of 1 to 2 sec.

Polypectomy and Mucosectomy 

Polypectomy in the small bowel is associated with an elevated risk of perforation.9, 10 As in upper GI and colon endoscopy, submucosal injection of a small amount of saline elevates the polyp from the lamina muscularis propria and, thereby, increases the safety margin (Fig. 2). Again, the power settings of the generator should be chosen as low as possible. In particular, the coagulation component should be kept to a minimum. Using the ERBE Vio 2 generator, it is recommended to use “Endo Cut Q” at “Effect 1” (or at most “Effect 2”), because higher “Effects” (≥3) may produce more in-depth coagulation which may result in direct or delayed perforation. If bleeding occurs, one might gently touch the bleeding lesion with the tip of the loop and coagulate (mode: “forced coagulation,” Effect 2, 60 W), or use a hot biopsy forceps. Alternatively, diluted epinephrine may be injected.

View Large Image Download to PowerPoint

Figure 2. Removal of a flat adenoma in the jejunum. (A) Native polyp. (B) Injection of 3 mL of diluted epinephrine. (C) Snare in position. (D) After diathermic removal.

Companies offer a variety of snares of different sizes (Table 1). Usually, a diameter of 10 to 15 mm is adequate. If polypectomy in a single piece seems too risky, large broad-based polyps or flat lesions can be removed using the piecemeal technique with a smaller snare. One company offers a snare with a special shape which can grasp smaller (15 mm diameter) and larger (30 mm diameter) areas.

The resected specimens may be captured with the snare itself, or, more elegantly, with a net-shaped basket. Resecting multiple polyps, as eg, in Peutz-Jeghers syndrome, is challenging and time-consuming. In this case, one might start with the resection of the most distant polyp, which can be retrieved by catching the polyp in the basket or loop and pulling the scope with its balloon deflated through the fixed overtube. After removing the distal balloon, the enteroscope can be reinserted and the other polyps may be subsequently removed.

Treatment of Enteral Stenoses 

DBE, for the first time, provides access to enteral stenoses and the treatment option of balloon dilation. The most favorable indications are short stenoses, eg, in Crohn’s disease or NSAID-induced scars. Malignant stenoses which cannot be treated by surgical resection may be dilated as well.1, 11, 12, 13

Dilations with through-the-scope balloons require the therapeutic enteroscope with a 2.8-mm working channel. In difficult anatomical situations, eg, angulated small bowel loops, it may be advisable to delineate the position of the stenosis by fluoroscopy using water-soluble contrast which may be applied via a ERC catheter or, if the channel is occupied by another tool, even via the overtube. The balloon may then be placed into the stenosis, and dilated at least to the diameter of the enteroscope which may be passed beyond the stenosis.1, 11, 12, 13 Even three or more stenoses can be successfully dilated, as we could show in a patient with Crohn’s disease who had already undergone multiple bowel resections.2 In this patient, we were able to re-establish the passage to the colon.

Whether wider diameters (>12 mm) should be chosen must be judged individually while keeping in mind the risk of perforation.1, 11, 12, 13 With forceful advancement, while slightly going to and fro, one will eventually succeed in pushing the balloon out of the distal tip, even in a curved and unfavorable position of the distal end.1, 11, 13

Using the diagnostic enteroscope with a narrow channel, the dilation may be performed using a different technique, as has already been described in the original DBE paper by Yamamoto and coworkers.11 A long flexible guidewire (0.035 inches, 650 cm) is introduced through the enteroscope and placed with its tip beyond the stenosis. The enteroscope is removed while leaving the guidewire and the overtube in place, and the balloon system is advanced to the stenosis where the dilation is performed under fluoroscopic observation. Subsequently, the endoscope may be reintroduced to document the success of the procedure.

The endoscope removal method may also be used to insert a stent introducer through the overtube and, thus, place a self-expandible metal stent (eg, Enteral Wallstent) into an enteral stenosis, as has been performed recently (A. Taylor, personal communication).13, 14 In our view, stenting of enteral stenoses is strictly reserved to inoperable patients with small bowel malignancy. The possibility of treatment failures (eg, stent dislocation) must be kept in mind. Also, despite technical success, more distal stenoses might cause occlusion and should be excluded before considering this procedure.

Retrieval of Foreign Bodies 

Foreign bodies, such as video capsules that have been retained because of an unexpected stenosis, can be retrieved by DBE (Fig. 3). The foreign body may be grasped by a basket or a snare which can be applied in both types of enteroscopes.15

View Large Image Download to PowerPoint

Figure 3. Extraction of a retained video capsule using a polypectomy snare. (Color version of figure is available at www.techgiendoscopy.com.)

Tattooing 

Pathologic findings, such as tumors that cannot be removed by standard polypectomy or endoscopic mucosal resection, may be marked for subsequent operative resection by injecting sterile ink into the submucosal layer (Fig. 4). It is advisable to ascertain that the needle tip is positioned correctly in the submucosa to avoid the peritoneal cavity being contaminated by transmural ink application. To achieve this, a small quantity of saline should be injected submucosally at first. Once lifting of the mucosa indicates the intramural position of the needle tip, the whole volume of ink (we use 5 mL per injection) can be securely applied. If no submucosal cushion appears, the injection should be repeated at another site.

View Large Image Download to PowerPoint

Figure 4. Application of a submucosal tattoo. Before ink injection, the correct position of the needle tip in the submucosa was ascertained. (Color version of figure is available at www.techgiendoscopy.com.)