The small intestine is the most difficult part of the luminal gastrointestinal tract to access. Since the advent of capsule, balloon and spiral enteroscopy techniques, we are capable to entirely visualize the mucosa of the small bowel. In addition, device-assisted enteroscopy techniques also allow us to provide endoscopic therapy for various small bowel disorders. Deep enteroscopy is performed in many centers around the world. This collaborative project is a testament to this universal procedure. The two main objectives of this teaching video are 1. To present the principles of deep enteroscopy using the most current techniques and 2. To demonstrate common and uncommon small bowel pathologies. The collection of pathologies and therapeutic interventions shown here is such that this teaching video also serves as a reference atlas for beginners and experts in small bowel diseases. There is a large variety of methods to investigate a small bowel. These methods are divided into radiologic, endoscopic and explorative laparotomy. We will now focus on endoscopic methods to visualize the small bowel mucosa. Without capsule endoscopy, deep enteroscopy using video endoscopes would make much less sense. Capsule endoscopy is a very valuable semi-noninvasive method to search for small bowel diseases. The capsules are pretty small, measuring about 1 inch long and a half inch wide. Current capsule endoscopes are able to shoot around 70,000 pictures and have batteries that last around 10 hours, allowing for recordings of the entire small bowel. Sensors are incorporated into a belt which is worn for the duration of the examination. The data recorder is attached to the sensor belt. The blinking light indicates a functioning capsule endoscope. The transit of the capsule endoscope can be traced using a mini monitor. The capsule endoscope can be easily swallowed with a glass of water. Often, capsule endoscopic findings are sufficient to determine medical management. Other times, capsule endoscopy findings will prompt an invasive enteroscopy to obtain tissue or perform a specific therapeutic intervention, such as argon plasma coagulation for bleeding lesions or resection of small bowel polyps. In patients with Crohn's disease, capsule endoscopy can be useful to reach a diagnosis, determine the extent of disease, and to evaluate mucosal healing. In patients with obscure GI bleeding, capsule endoscopy can be useful to determine the source and guide therapy. In this patient with small bowel angio-dysplasias, a balloon enteroscopy was then performed and the angiovascular malformations were cauterized using argon plasma coagulation. Capsule endoscopy is also useful to evaluate patients with malabsorption. However, if tissue for diagnosis is required, then a deep enteroscopy is indicated. Capsule endoscopy is also useful to diagnose and monitor patients with polyposis syndromes, such as Poitier-Jager syndrome or familial adenomatous polyp syndrome, FAP. Capsule endoscopy can also be useful to find small bowel tumors, such as this case of adenocarcinoma. However, submucosal tumors, such as gastrointestinal stromal tumors, are often missed by capsule endoscopy. Modern invasive small bowel endoscopy is now defined as device-assisted enteroscopy. These methods truly allow for a deep inspection and therapeutic interventions of the small bowel. Those, we call them collectively deep enteroscopy. Thus, invasive enteroscopy remains a very important tool for diagnosing and treating small bowel disorders. Most of the literature available on deep enteroscopy deals with double balloon enteroscopy. However, recent data suggests that all three devices have similar capabilities to inspect the small bowel when the approach is from the oral route. Nonetheless, when inspecting the small bowel from the anal route or when defining total enteroscopy as entire small bowel visualization using both the oral and anal routes, both double and single balloon enteroscopy have better percentages of completeness. In addition, the diagnostic yield and amount of therapeutic interventions is higher when using balloon-assisted methods. The indications for deep enteroscopy are broad. The most common indication is obscure gastrointestinal bleeding, either occult or overt. Other important indications are the evaluation of ulcerative and malabsorptive small bowel conditions such as Crohn's disease and celiac disease. Because capsule endoscopy is a non-invasive imaging test, it is often used first in patients with suspected small bowel disorders. This often leads to findings that require deep enteroscopy. The main advantage of deep enteroscopy is its ability to provide endoscopic therapy. This slide clearly demonstrates that the most common indications for deep enteroscopy are obscure gastrointestinal bleeding and Crohn's disease. First, we will briefly show the principles of various methods for deep enteroscopy. We will then focus on live oral balloon enteroscopy followed by anal enteroscopy. During the next few minutes of the demonstration, we will show you some basic technical aspects and then provide you with several useful tips and tricks to perform deep enteroscopy. Patient preparation for deep enteroscopy follows the same principles as for any endoscopy of the gastrointestinal tract, including a thorough history and physical examination and review of the laboratory and x-ray data. In contrast to other luminal gastrointestinal endoscopies, though, deep enteroscopy can result in pancreatitis in about 1-2% of cases. This potential complication should be explained to the patients during the preoperative informed consent. The type of sedation employed depends on the patient's clinical status as assessed by the American Society of Anesthesiology Classification and the disease process being investigated. Patients with comorbidities or those being investigated for severe or complex diseases should preferably undergo the procedure under general anesthesia or professionally supervised deep sedation. The guidelines for the use of NAPs vary amongst various countries. Nevertheless, the scientific literature has documented the safety of NAPs, therefore making it our preferred method of sedation. There are some relative and absolute indications for the use of fluoroscopy during deep enteroscopy. A relative indication is its utilization during the initial learning curve of deep enteroscopy or in those low-volume centers. Absolute indications are for therapeutic interventions such as extraction of foreign bodies, stent placement, and dilation of small bowel strictures, as will be explained and demonstrated in this teaching video. Modern deep enteroscopy is a modification of push enteroscopy, where the overtube plays a central role to manipulate the intestines and allow for advancement of the enteroscope. For double balloon enteroscopy, two balloons are necessary to retract and stabilize the small bowel. The balloons are inflated and deflated using a special balloon pump controller. Understanding the basic mechanisms of the technique of double balloon enteroscopy will enable you to comprehend and master the aspects of the other methods of deep enteroscopy. The key to success in investigating and treating small bowel disorders lies in knowing the technique and a coordinated teamwork. The mechanism of double balloon enteroscopy is a utilization of one balloon on the scope and one on the overtube, which allow for pulling back or retracting the small bowel proximal to the overtube and then allow for advancement of the enteroscope. Single balloon enteroscopy is a modification of double balloon technique. Here only one balloon on the tip of the overtube is utilized. The principle of pushing and pulling is the same as in double balloon enteroscopy. Spiral enteroscopy uses the principle of corkscrewing the overtube inside the intestines. Advancement is really fast, however deep intubation is less than with balloon assisted techniques. The balloon enteroscope consists of a special enteroscope, overtube, balloons and the balloon pump controller. We also like to use a flushing pump connected to the working channel of the enteroscope. Before starting the procedure, we always make sure that all the connecting lines, balloons and water pump work perfectly. Newer overtubes come with a special latex seal which allows for the overtube to get attached to the handle of the enteroscope. The attachment of the overtube to the enteroscope impedes sliding of the tube while inserting and handling the enteroscope. Intubation of the esophagus using the enteroscope is the same as with a gastroscope. Once the tip of the endoscope has reached the stomach, the overtube is handed over to the assistant. While the endoscopist holds back on the endoscope, the assistant carefully advances the overtube until the mark on the scope is reached. The enteroscope is always advanced using slight torquing, pushing and pulling maneuvers. This close-up view exemplifies the key handling maneuvers of the enteroscope. These maneuvers prevent overstretching of the bowel while they permit the smooth advancement of the enteroscope within the lumen. Once the overtube has reached the scope and both balloons are inflated, the assistant or endoscopist pulls both out. It is important to keep the enteroscopic position while pulling back. Both the assistant and endoscopist should keep an eye on the monitor. This maneuver can also be performed by an endoscopist. The key aspects are to hold both the overtube and the scope tightly and pull out smoothly. This is another example of scope and balloon pull-out using the single-balloon system. Once the overtube has reached the tip of the scope and the overtube balloon is inflated, the shortening or pull maneuver can be performed. Note how the small bowel is shortened or contracted. After pulling out, a new cycle begins and the scope is pushed in again. Sometimes, while we perform the shortening or pull maneuver, we also advance or push the scope simultaneously. This method is useful at the beginning of the investigation, and it may shorten the procedure time. However, if using a double-balloon enteroscope, remember to deflate the scope balloon before pushing the scope while pulling the inflated overtube. Occasionally, total enteroscopy can be achieved when performing oral enteroscopy. This is not common. Usually, it is necessary to perform both oral and anal balloon enteroscopies to achieve a total inspection of the small bowel. This video shows you a total enteroscopy. The enteroscope traverses the eunum and reaches the terminal ileum. Note how the scope traverses the proximal part of the ileocecal valve to then smoothly enter the cecum. While introducing the enteroscope into the rectum and advancing through the sigmoid colon, it is useful to keep the handle of the scope at a higher position to prevent the overtube to slide down. The scope is advanced similarly to a colonoscopy. Once the scope has been inserted, the overtube is handed over to the assistant. The overtube is advanced over the scope. Once the overtube has reached the tip of the scope, the balloon is inflated and the assistant pulls out. One of the key aspects for a successful ileum intubation is to have the ileocecal valve on the left side of the monitor. Another key trick to intubate the ileum is to have enough scope out of the overtube. This allows for better manipulation of the endoscope. The scope is twisted to the left and the big wheel is turned up. Immediately after entering the ileum, the scope is pulled out slightly, then immediately twist the shaft to the right and gently push in while carefully blowing some air with the blue button. The overtube should be held straight to allow the endoscopist to push the scope deeply into the ileum. While the endoscopist pushes the endoscope, the assistant should counter-tract with the overtube. Once the scope is about 20 to 30 cm inside of the terminal ileum, the overtube is pushed inside. This video shows the smooth advancement of the scope during an anal balloon enteroscopy. Spiral enteroscopy is based on the utilization of an overtube, which has a corkscrew-like tube called on its tip. Any enteroscope and also pediatric colonoscopes can be inserted through the tube to perform the procedure. In contrast to balloon enteroscopy methods, where the push and pull maneuvers are essential to advance the scope, during spiral enteroscopy the luminal advancement occurs as a screwing movement, which is induced by a clockwise twisting or turning on the handles of the overtube with both hands. An essential part of deep enteroscopy is to know the appearance of the normal mucosa. There are many diseases such as celiac disease, Whipple's disease and inflammatory jejunitis that may result in only minimal mucosal changes. The water immersion technique is a very useful technique to characterize the small bowel villi. It is particularly useful when evaluating patients with celiac disease. This patient has normal villus architecture. Chromoendoscopy of the small bowel can be useful to detect and characterize polyps and tumors. In FAP adenomas, they appear as wide, flat polyps. Virtual chromoendoscopy with magnification techniques allow for further characterization of mucosal vessels, villi and abnormal structures. As in any part of the luminal gastrointestinal tract, advanced endoscopic methods are gaining in importance in small bowel endoscopy. Several studies have shown that advanced imaging methods such as virtual chromoendoscopy are useful for the detection and characterization of small bowel adenomas and angio-dysplasias. Eye scan is a new dialysed chromoendoscopy method that enables the characterization of mucosal surface and subsurface patterns. The villus architecture in Peyer's patches can be characterized very well as seen in this example. Confocal laser endomicroscopy is based on tissue illumination with a low-power laser. The laser light is reflected from the tissue and refocused onto the detection system by the same lens, meaning that only returning light refocused through the pinhole is detected. Therefore, confocal laser endomicroscopy provides high-resolution images, thus enabling optical biopsies and in vivo histology. The thousand-fold image enhancement clearly allows for a detailed villus examination. When utilizing two or more advanced small bowel methods, we call it multi-modal small bowel endoscopy. There is a wide variety of utensils and accessories for small bowel endoscopy available, ranging from snares, biopsy forceps, nets, needles, probes, etc. The most common procedure done during deep endoscopy is tissue retrieval with biopsy forceps. Histology is essential for the diagnosis of common and uncommon small bowel diseases. is important to mark lesions and thus help the surgeon find those during operation. However, the most common indication for tattooing is to determine the deepest point of insertion during oral or anal deep endoscopy. When performing the endoscopy on the opposite route, finding this spot will indicate a total small bowel inspection. Endia-ink can result in mucosal and peritoneal inflammation. Because we prefer to pre-inject first with saline, create the bleb, and then inject the ink into the mucosal cushion. This video shows how the submucosal bleb is created first, followed by injection of the ink into the bleb. We want to emphasize that since the advent of deep endoscopy, the nomenclature of gastrointestinal bleeding has changed. We now talk about upper, middle, and lower GI bleeding. The books on GI bleeding are now being rewritten. The most common cause of small bowel bleeding are angiovascular dysplasias or angiovascular malformations. Occasionally, these are found actively bleeding, but most of the time, arteriovascular malformations are found in patients with obscure occult GI bleeding, such as in this patient with Osler-Weber-Rendoux. This pulsating lesion on the left is a du LaFoix's lesion, which had already resulted in massive bleeding requiring the transfusion of 10 units of packed red blood cells. Portal jejunopathy is a relatively new condition that in the past was unrecognized. Now we know that portal jejunopathy is an important cause of GI blood loss in cirrhotic patients. Anastomosis and enteritis should be always considered in patients with previous radiation for pelvic and gynecologic tumors. Patients with Roux-en-Y anastomosis can bleed from the anastomosis. In the past, reaching this area was almost impossible. The use of a water flush is a definite advantage of deep enteroscopy over capsule endoscopy. The water flush is useful to remove blood and blood clots. Capsule endoscopy and deep enteroscopy are complementary tests in the evaluation of obscure GI bleeding. We have proposed this practical algorithm to investigate and treat patients with obscure gastrointestinal bleeding. We always repeat both EGD and colonoscopy as we have previously demonstrated that up to 30% of lesions are missed by previous endoscopies. If the repeat endoscopies are negative and the bleeding persists, we use capsule endoscopy first if there is occult obscure GI bleeding, but prefer to use deep enteroscopy methods if the bleeding is overt. Always keep in mind that angiography, computed tomography and surgical intervention may be life-saving in certain circumstances. The spectrum of ulcerative giunitis is growing and includes Crohn's disease, non-steroidal anti-inflammatory agents, vasculitis and infections. The endoscopic differentiation of Crohn's from other causes of ulcerative giunitis can be very difficult. Crohn's disease results in small and large ulcers and is often accompanied by mucosal pseudopolyps. The ulcers of non-steroidal giunopathy tend to occur on the tip of the folds and are often circumferential. In Crohn's disease, the ulcers more often follow the longitudinal axis of the intestine. Histology can be of paramount importance to define the etiology of ulcerative giunitis. In amyloidosis, the ulcers are usually deep, confluent and large. Crohn's disease of the small bowel often results in aftos lesions. However, other diseases, such as Beschett's disease, can cause these same erosions. The endoscopic spectrum of Crohn's disease of the small bowel is wide and our experience continues to expand. Here we appreciate the large variety of ulcers which can be superficially, but also confluent and other times deep with associated stenosis of the affected segment. The videos show the endoscopic appearance of two different patients with Crohn's disease of the small bowel. We always correlate the endoscopic findings with histology and the clinical and laboratory data of the patient, as there are no set criteria to make a diagnosis of Crohn's based solely on endoscopic appearance. Celiac disease can affect any part of the small bowel. Occasionally, celiac disease only affects the jejunum or ilium. Classic endoscopic findings of celiac disease are serrated mucosal folds and mossy system of the mucosa. The immersion technique is of paramount importance for the evaluation of patients with SPRU. Notice the flat villi and mossy system of the mucosa. The presence of small erosions, ulcerated folds, masses or ulcers suggest the presence of EATL or Enteropathy Associated T-Cell Lymphoma. The endoscopic spectrum of Whipple's disease is broad. Recently, we described the presence of ring-like structures inside of the engorged small bowel villi. In addition, the presence of a milky exudate suggests lymphangiectasias, which are very common in Whipple's disease, as the lymphatic drainage is blocked by the bacilli, which invade the submucosal lamina propria and lymphatic vessels. Now we are able to diagnose infectious diseases such as Whipple's disease during live endoscopy using confocal laser endomicroscopy. Since the advent of deep enteroscopy, we have been diagnosing more malignant tumors of the small bowel in alive patients. Formerly, these tumors were mainly diagnosed at autopsy. This circumferential mass and stenosis is a classic appearance of small bowel adenocarcinoma. Often adenocarcinoma of the small bowel presents as a vulnerable ulcerated mass. This ulcerated mass can be huge and penetrate deeply into the serosa or adjacent intra-abdominal structures. Another common small bowel tumor are GISTs or gastrointestinal stromal tumors. These tumors originate from the cells of Cajal and those are located submucosally. Often they only become apparent when they bleed, cause obstruction or metastasize. This patient with neurofibromatosis von Recklinghausen's disease had a large GIST of the upper jejunum. Bleeding from a GIST is usually massive and requires the joint action of endoscopists, surgeons and radiologists. Neuroendocrine tumors of the small bowel are very difficult to diagnose. In general, many tests are necessary to detect such tumors. Neuroendocrine tumors typically present as submucosal masses. Occasionally, neuroendocrine tumors ulcerate through the mucosa. Ulcerated carcinoids are mostly yellow ulcers. Neuroendocrine tumors rarely bleed. However, when this happens, the bleeding is usually massive and severe. Kaposi's sarcoma is an infectious disease caused by a herpes virus. Small bowel Kaposi's presents as submucosal hemorrhages, mucosal edema, thickened folds, vascular malformations or larger red-purplish nodules. The main hemostatic methods used for small bowel bleeding are injection, argon plasma coagulation and CLIPS. This patient with a large bleeding, du Lafoie's lesion is being treated with fibrin glue injection. When performing argon plasma coagulation or APC of the small bowel, careful attention must be paid to the settings used as the power coagulation energy delivered with the same watts differs among the APC generations used. Too many watts can lead to a catastrophic perforation. Gentle but efficient and coordinated movements of the probe and scope are mandatory when performing APC. In patients with Osler-Weber-Rindau, we only perform APC when there is proximal jejunal disease and less than 100 lesions or there is clinical bleeding. In addition, we do not perform more than 25 APC applications per endoscopic session. Several types of CLIPS can be applied through the working channel of the enteroscopes. CLIPS are particularly useful for sealing visible, active spurting or oozing vessels. The resolution CLIPS have the advantage of reopening and repositioning capabilities. This permits for a more targeted and specific deployment of the CLIP. Endoscopic resection of polyps is the second most common therapeutic intervention of the small bowel. The most common indications for polypectomy or mucosectomy are Poitz-Jager syndrome and familial adenomatous polyposis syndrome. Because the small bowel wall is very thin, we generally use injection-assisted polypectomy methods or the submucosal cushion. Be careful with the use of epinephrine as there are reports of small bowel infarctions due to epinephrine. In this patient with Poitz-Jager syndrome, we removed 20 hamartomatous polyps during one session. There are several types of snares that can be used during enteroscopy. Advanced neoplasia or lesions larger than 10 mm in size should be removed using mucosectomy or piecemeal mucosectomy techniques. The three most common causes of small bowel strictures of the small bowel are Crohn's disease, tumors, and non-steroidal anti-inflammatory drugs. The endoscopist should attempt to define whether the stricture is inflammatory or fibrotic. Inflammatory strictures should be managed medically. Fibrotic strictures are amenable to endoscopic therapy if they are few, less than 3 or 4 mm long and not too tight. We always use fluoroscopy when dilating strictures. The use of contrast during fluoroscopy can be very helpful to define the type and the length of a given stricture. In addition, fluoroscopy is essential to follow the wire inserted through the stricture. The size of the balloon used for dilation will depend on the appearance of the stricture. We prefer to use, through the scope, over the wire, three-staged balloons. Once the balloon catheter has been advanced through the stricture, a coordinated balloon dilation ensues. It is often helpful to gauge the success of dilation by looking at the fibrotic channel throughout the inflated balloon. The most common foreign body extracted with deep enteroscopy methods are retained capsule endoscopes. Most capsule endoscopes get stuck at tumors and small bowels, Crohn's strictures. This case demonstrates a classic impaction of a capsule endoscope in a patient with Crohn's strictures. We recommend using fluoroscopy when retrieving foreign bodies. Fluoroscopies may not only help to locate the target, but will also be helpful to define the length and type of stenosis. Large coins can get trapped in the small bowel, especially if strictures are present. Currently, there are many case reports documenting on the successful extraction of various types of needles from the small bowel. Even larger foreign bodies, such as partial dentures, can be removed using deep enteroscopy techniques. Self-expandable metal stents may be useful to palliate malignant small bowel strictures. First, we locate the stenosis endoscopically. Then a wire is placed through the stenosis. The overtube is left in place while the endoscope is removed over the wire. Then a stent is advanced over the wire and released under fluoroscopic control. Deep enteroscopy has also gained importance for the evaluation of patients with gastric bypass and excluded stomach. If necessary, even a percutaneous gastrostomy PEG tube can be placed using the deep enteroscopy technique. The performance of direct percutaneous endoscopic eunostomy has also been reported by us and others. We have proposed an algorithm for categorizing the complications associated with deep enteroscopy. There are complications which are common to both diagnostic and therapeutic enteroscopy and complications resulting mainly from therapeutic interventions. The most common complication of deep enteroscopy, either diagnostic or therapeutic, is pancreatitis. Bleeding is mainly associated with therapeutic enteroscopy. However, perforation, although rare, can occur both after diagnostic or therapeutic interventions.

deep enteroscopy

small intestine

capsule endoscopy

double balloon enteroscopy

single balloon enteroscopy

spiral enteroscopy

small bowel disorders