LITMIR.BIZ

Скачать книгу

      Variceal ligation

      In patients with active bleeding from EV, hemostasis can be achieved by band ligation. This is a local endoscopic therapy that involves placing a rubber band around the culprit EV. Band ligation is also performed in patients requiring primary or secondary prophylaxis for EV bleeding. This typically consists of repeated sessions of band ligation until the varices are obliterated. Sclerotherapy with injection of sodium morrhuate (5%) and sodium tetradecylsulphate (1%) is also an option [17]. However, this has been largely replaced by band ligation.

      Local endoscopic therapy for management of gastric varices (GV) may involve transendoscopic obturation by injection of cyanoacrylate glue into the varices [18,19]. There is a small probability of fatal pulmonary embolism [20]. While cyanoacrylate glue is commonly utilized in Europe and Asia, it is not yet approved for this specific use in the United States.

      Stricture dilation

      Options available for stricture dilation include tungsten‐weighted dilators that do not require endoscopy or sedation, wire‐guided bougie dilation, or TTS balloon dilators, the latter of which allow for dilation under direct endoscopic visualization [21]. The TTS balloon dilators are 3.0–8.0 cm in length and range from 6.0 to 20.0 mm in diameter. Under direct visualization, the soft tip of the balloon dilator is advanced gently past the stricture and the balloon is inflated. For complex strictures, fluoroscopy is useful to delineate anatomy and confirm that the tip of the balloon is in the lumen beyond the stricture. Dilation carries a significant perforation risk of approximately 1–2%, and it is common to dilate strictures gradually over a period of days to weeks [22].

      PEG tube placement

      PEG tubes can provide enteral nutrition to patients with chronic feeding problems stemming from neurologic conditions, malignancies, or other associated medical disorders. The trainee should learn that there are contraindications to placement of PEG tubes, which include the presence of bowel distension or obstruction, ascites, obstructing esophageal or gastric malignancies, and the presence of portal hypertension or other hypercoagulable states. The pull technique is illustrated in Chapter 30 of this book (Figure 30.1) and remains the most popular method of placement. This technique commonly requires two physicians, one performing the endoscopy and one responsible for the cutting portion. With the patient in the supine position, the endoscope is advanced into the stomach. The stomach should be fully insufflated and a point of maximum transillumination should be identified along the anterior wall of the stomach. Using a single finger, one‐to‐one indentation of the abdominal wall should be seen by the endoscopist. If this is unable to be achieved, there may be overlying bowel loops or fluid, and PEG placement should not occur via endoscopic means.

Once the insertion site is identified, local anesthesia with 1% lidocaine should be injected at the site. The second physician should make a small skin incision at the site measuring approximately 1.0 cm. The trocar with the introducer needle should then be advanced through the incision, maintaining the trocar at a 90° angle. The needle should then be removed, and a guidewire introduced through the trocar. The endoscopist should grasp the guidewire with a snare and remove the endoscope along with the guidewire through the mouth. The suture loop attached to the PEG tube should then be tied to the guidewire. The opposite end of the guidewire should be gently pulled away from the abdominal wall so that the PEG tube can be pulled into the stomach until the bumper is along the anterior gastric wall. It is recommended to reintroduce the endoscope to confirm proper placement of the PEG bumper. Once confirmed, the external portion of the PEG tube can be cut to the desired length and secured. There are variable data regarding when tube feeds following PEG tube placement can be initiated. Traditionally, tube feedings have been delayed until the next day or up to 24 hours after PEG placement if the PEG site is intact and the abdominal exam is benign. However, some data suggest that early feeding (less than 4 hours after placement) is a safe alternative to delayed feeding with no overall differences in complication rates [23].

      Stenting

Placement of endoscopic stents can be considered for palliative treatment of malignant strictures, for refractory benign esophageal strictures, and for management of esophageal perforations and fistulas. Uncoated (also called uncovered) self‐expanding metal stents (SEMS) are associated with extensive hyperplastic tissue ingrowth that can prevent removal and eventually result in obstruction [24]. For this reason, partially covered esophageal SEMS have replaced uncovered esophageal SEMS for the palliation of malignant obstruction. Fully covered SEMS can generally be removed (Figure 5.12) and have therefore been used for perforations or strictures that do not respond to standard dilation. However, as stents carry significant risks of migration and perforation, it is reasonable to attempt at least three standard endoscopic dilations of benign strictures and consider the addition of four‐quadrant steroid injection of the stricture prior to stenting. Most esophageal stents are delivered over a guidewire after first removing the endoscope, typically with fluoroscopy to confirm positioning. A standard or ultrathin endoscope can be advanced alongside the stent delivery catheter to observe the deployment. Some newer stent models with less bulky delivery systems can be placed directly through the endoscope channel (TTS).

      Advanced endoscopic resection and endoscopic submucosal dissection

Standard snare polypectomy and endoscopic mucosal resection of polyps are skills that are generally learned during colonoscopy training, as these procedures are more commonly performed in the colon. In the United States, endoscopic submucosal dissection (ESD) is not yet widely practiced, unlike in Asia where it is frequently used to treat early gastric cancer in endemic areas. Training for ESD and related techniques such as tunneling resection or per‐oral endoscopic myotomy (POEM) is generally not part of standard gastroenterology fellowship programs; after acquiring skills in standard EGD, physicians that are interested in learning ESD or POEM may choose to obtain training in specialized advanced endoscopy programs in the United States or overseas [25]. Educational courses, such as those offered by ASGE, can provide an introduction to the techniques and may include hands‐on training using ex‐vivo porcine models, which provide a realistic experience aside from the absence of bleeding and fibrosis. There are several noteworthy technical aspects of ESD that deserve mention. Many gastric lesions are best approached with the endoscope retroflexed because the endoscope tip is often more stable in retroflexion (the angulated portion of the shaft rests stably in contact with the gastric wall) and because the electrocautery knives used often approach the lesion at an optimal angle parallel to the submucosal plane. During training, the endoscopist must therefore become familiar with maneuvering of the retroflexed endoscope. Fine tip control using both the up–down and left–right dials is important during ESD. For this reason, many endoscopists performing the procedure hold the endoscope in an alternative position in which the index and middle finger wrap around to support the dials rather than resting on the suction and insufflation buttons (Figure 5.13). Because of the complex and repetitive motions required during ESD, some endoscopists prefer to have an expert assistant hold the shaft or advance the electrocautery knife as required.

Figure 5.12 (a) Mid‐esophageal cancer with luminal obstruction. (b) Subsequent stent placement over the area occupied by the neoplasm.

Figure

Скачать книгу