Therapeutic Applications of Wired Enteroscopy: When & How?

Transcription

1 Session I LGS-I: Small Bowel Endoscopy: What Can We Do in 2013? Therapeutic Applications of Wired Enteroscopy: When & How? Hironori Yamamoto, M.D. Gastroenterology Center, Jichi Medical University, Shimotsuke, Tochigi, Japan Introduction The small bowel is a long (5 7 m) and tortuous organ that is freely mobile in the abdominal cavity. These anatomical features complicate endoscopic examination using conventional endoscopes and have kept this region the uncharted territory of endoscopy. Double balloon enteroscopy (DBE) was developed to overcome the limitation of conventional push enteroscopy. 1 DBE features not only deep intubation of the small bowel, but also the improved control of the endoscope tip, even in the distal small intestine. DBE enabled endoscopic scrutiny and therapeutics in the small intestine. Single balloon enteroscopy (SBE) was developed later as a simplified form of DBE. SBE omits endoscope balloon of DBE. In SBE, instead of endoscope balloon, hooking with the endoscope angle is used to grip the small intestine. Balloon assisted enteroscopy (BAE) is the general term for DBE and SBE. BAE revolutionized the management of small intestinal diseases. In this lecture, therapeutic applications of wired enteroscopy, mainly focusing on DBE, will be explained. Basic principles For the proper use of DBE, it is important to understand how DBE works. DBE enables deeper intubation of the small intestine by effective shortening of the intestine. In push enteroscopy, advancement occurs at the expense of constant stretching and lengthening of the intestine. The transmission of force to the endoscope tip diminishes, resulting in lack of advancement of the endoscope (Figure 1, upper panel). DBE solves this problem by mounting a balloon onto a flexible overtube, which is passed Figure 1. Basic principles of double balloon enteroscopy. Upper panel: Stretching of a curved intestine in push enteroscopy. Lower panel: Inhibition of intestinal stretching by the overtube with balloon attached. 112 IDEN 2013

2 LGS-I: Small Bowel Endoscopy: What Can We Do in 2013? over the scope. Once inflated, the balloon grips and holds the intestine in place, preventing stretching of the intestine. Consequently, advancement of the endoscope shaft does not stretch the intestine, and the pushing forces are more effectively transmitted to the endoscope tip (Figure 1, lower panel). 2 Endoscopic therapies Endoscopic therapy using standard colonoscopy accessories is possible using the therapeutic type of DBE and SBE. Therapy includes hemostasis with clips (Quick Clip HX 201UR and EZ Clip HX 610, Olympus, Tokyo, Japan; Resolution Clip 2261, Boston Scientific, Natick, Massachusetts, USA), and argon plasma coagulation (APC) (APC 300 and Erbotom ICC 200, Erbe Elektromedizin, Tüebingen, Germany), polypectomy, endoscopic mucosal resection (EMR), balloon dilation (CRE Wireguided Balloon Dilator, Boston Scientific), stent placement, and retrieval of foreign bodies. In the small intestine, we carry out APC with the argon gas flow rate at 2.0 L/minute, and the electric current at 40W. In order to obtain the maximum control of the accessories during endoscopic therapy, the endoscope shaft should be maximally straightened before passing the accessory. This is possible by gently pulling and shaking the endoscope shaft with both the balloons inflated to grip the intestine near the lesion. When the insertion of accessory devices is difficult due to looping of the endoscope, a small amount of olive oil can be injected through the accessory channel for lubrication. Many types of endoscopic therapies become easier with a 4 mm transparent hood mounted to the tip of the endoscope. The hood minimizes the need for air insufflation and maintains the endoscopic view by keeping the endoscope tip a fixed distance from the target. Because the intestinal wall is thin, careful attention should be paid to prevent complications, such as perforation, when performing endoscopic therapies. Submucosal injection of % saline ± epinephrine is useful for the prevention of bleeding and perforation. Impact on management of small intestinal diseases DBE enables endoscopic treatment of small intestinal diseases that historically required open surgery. For ex- A B Figure 2. (A) Identification of the bleeding point with observation under water. (Bb) Endoscopic hemostasis with clip placement. IDEN

3 IDEN 2013 A B C Figure 3. (A) Anastomotic stricture in a patient with Crohn s disease. (B) Balloon dilation using a controlled radial expansion balloon catheter (CRETM Wireguided Balloon Dilator, Boston Scientific). (C) Endoscopic view after the dilation. ample, endoscopic hemostasis and accurate diagnosis of the bleeding source may avoid surgical exploration and possible resection of the intestine (Figure 2). Endoscopic polypectomy in the small intestine has dramatically changed the management of patients with Peutz Jeghers syndrome. 3 Endoscopic dilation of small intestinal strictures may avoid or reduce the number of surgical resections (Figure 3). Even in diseases that require surgical resection for curative therapy, such as small intestinal tumors, early detection and accurate diagnosis by DBE may improve the prognosis of the patients. Endoscopic classification of vascular lesions of the small intestine Small intestinal vascular lesions are often reported as angiodysplasia or arteriovenous malformation (AVM). However, small intestinal vascular lesions observed by endoscopy vary in appearance. Angioectasia is a venous lesion that requires cauterization; a Dieulafoy s lesion and AVM may cause arterial bleeding, which requires clipping or laparotomy. We have proposed an endoscopic classification of small intestinal vascular lesions, Yano Yamamoto classification, for better description of characteristics of the lesions and better selection of the appropriate treatment. 4 We classified vascular lesions in the small intestine into the following 6 groups (Figure 4): Type 1a, punctulate erythema (<1 mm), with or without oozing 114 IDEN 2013

4 LGS-I: Small Bowel Endoscopy: What Can We Do in 2013? Type 1b, patchy erythema (a few mm), with or without oozing Type 2a, punctulate lesions (<1 mm), with pulsatile bleeding Type 2b, pulsatile red protrusion, without surrounding venous dilatation Type 3, pulsatile red protrusion, with surrounding venous dilatation Type 4, other lesions not classified into any of the above categories Being different in size from one another, types 1a and 1b are both venous/capillary lesions and are considered angioectasia. Type 2 Figure 4. Endoscopic classification of small intestinal vascular lesions (Yano Yamamoto classification). lesions, subclassified into type 2a and 2b based on the presence or absence of protrusion, are arterial lesions and are considered Dieulafoy s lesions. Type 3 represents AVMs. Type 4 is a vascular lesion with unusual morphology and is unclassifiable. I believe that this classification is useful for selecting the hemostatic procedure and outcome studies. Tips & Tricks for easy control of the endoscope 1. Insertion with the minimum of force Forceful insertion doesn t work in BAE because gripping force by the balloon is limited to minimum to minimize the risk of perforation. Therefore, techniques for BAE should enable the advancement of the endoscope tip with the minimum of force. Endoscope advancement is supported by the inflated overtube balloon; inflation is kept to a minimum to ensure safety. Forceful insertion withdraws the overtube rather than advancing the endoscope tip. The proper insertion force needs to be applied to advance the endoscope tip smoothly. Forceful insertion of a sharply angled endoscope should be avoided. The operator should insert the endoscope while reducing the angle as much as possible and swinging the tip so that the endoscope forms a large arc. 2. Avoid making complicated loops Small intestine can make complicated loops. If complicated loops are made, insertion force applied to the endoscope shaft cannot be transmitted to the endoscope tip effectively even with BAE. Successful BAE requires an understanding of how the configuration of the endoscope and inflation of the balloon affect advancement. During training, fluoroscopic monitoring is very helpful. The configuration of the endoscope can be optimized under fluoroscopy by retracting the endoscope and the overtube with both balloons inflated. Jiggling movement during the retraction is useful to simplify the shape of the endoscope shaft. With experience, fluoroscopy becomes unnecessary for insertion of BAE. IDEN

5 IDEN Avoid over insufflation Air insufflation during insertion must be kept to a minimum. Air pockets will encumber pleating of the intestine over the overtube. Less air will also minimize patient discomfort. A short hood attached to the tip of the endoscope is useful to keep the tip a distance from the wall, and therefore reduce the need for air insufflation. The hood will also help to negotiate bends. The use of CO2 instead of air for insufflation is also recommended. CO2 insufflation In BAE, insufflated gas is trapped by the balloons. The trapped gas in the small intestine hampers the shortening of the small intestine. Because CO2 is absorbed rapidly from the intestinal lumen, effective shortening of the small intestine can be easily achieved by using CO2 insufflation. Effective shortening of the small intestine enables better arrangement of the shape of the endoscopic shaft, which provides better control of the endoscope tip and accessory devices in therapeutic application. Patient s discomfort due to bowel distention after the procedure can be avoided by CO2 insufflation. Conclusions BAE has dramatically improved small bowel diagnoses and therapeutics. It is important to maintain good control of endoscope by arranging the shape of the endoscope shaft for effective procedures of BAE. Transparent hood, CO2 insufflation and submucosal injection are useful tips to make endoscopic treatment in the small bowel easier and safer. References 1. Yamamoto H, Sekine Y, Sato Y, Higashizawa T, Miyata T, Iino S, Ido K, Sugano K. Total enteroscopy with a nonsurgical steerable double balloon method. Gastrointest Endosc 2001;53: Yamamoto H. Foreword: double balloon endoscopy. Gastrointest Endosc 2007;66:S2. 3. Sakamoto H, Yamamoto H, Hayashi Y, Yano T, Miyata T, Nishimura N, Shinhata H, Sato H, Sunada K, Sugano K. Nonsurgical management of small bowel polyps in Peutz Jeghers syndrome with extensive polypectomy by using double balloon endoscopy. Gastrointestinal endoscopy 2011;74: Yano T, Yamamoto H, Sunada K, Miyata T, Iwamoto M, Hayashi Y, Arashiro M, Sugano K. Endoscopic classification of vascular lesions of the small intestine (with videos). Gastrointest Endosc 2008;67: IDEN 2013