Gastroenterological Endoscopy. Группа авторов
does decrease the rate of other adverse events, such as stent migration and tumor ingrowth.26 After placement of a stent across the gastroesophageal junction, proton pump inhibitor (PPI) use and postural precautions are mandatory. The efficacy of antireflux stents has not been established.27
Late complications of stenting also include relapsing stenosis due to tissue hyperplasia (in the uncovered parts of partially covered stents) and tumor overgrowth. If the stent is placed for a benign indication, tissue hyperplasia may be treated by temporary placement of a second fully covered stent inside the first one, which will pressure necrose the inflammatory tissue and allow stent removal.24,25,26 Following SEMS removal, secondary fibrotic strictures at the proximal or distal ends may occur, and are usually easily managed with dilation.
Polypectomy, Endoscopic Mucosal Resection, and Endoscopic Submucosal Dissection
Polypectomy, endoscopic mucosal resection (EMR), and endoscopic submucosal dissection (ESD) are commonly associated with bleeding, although most bleeding is intraprocedural, controlled endoscopically, and is not clinically relevant. Perforation occurs in 3% of esophageal resections and in 1% of gastric resections.28,29,30 Cicatricial strictures are a late complication that mainly occur after circumferential esophageal resection.31 Delayed bleeding after esophageal or gastric EMR/ESD is uncommon (< 5%).28,30 To prevent delayed bleeding, some authors recommend coagulation of all visible submucosal vessels during the procedure for gastric resections, but this and second-look endoscopy are not routinely recommended.32 PPI therapy is usually prescribed after the procedure. Delayed bleeding occurs more frequently after duodenal mucosal resection compared with esophageal and gastric resection, with bleeding rates ranging from 4 to 33%. Some authors suggest closure of the mucosa after resection with placement of multiple clips.33
In the last two decades, ablative therapies (such as argon plasma coagulation, photodynamic therapy, and mainly radiofrequency ablation) have emerged for the treatment of premalignant or early superficial malignant lesions, and as palliative therapy for some advanced tumors. Photosensitivity is a specific complication associated with the use of photodynamic therapy, but can also result in the development of strictures, especially when applied in the esophagus.34,35 Stricture formation as a late complication can occur after circumferential radiofrequency ablation for treatment of dysplastic Barrett’s esophagus.
Hemostasis of Nonvariceal Bleeding
Hemostasis of nonvariceal bleeding includes a combination of injection therapy and thermal or mechanical therapy. Although adrenaline injection (0.1 mg/mL) does not result in complications, injection of sclerosants (such as polidocanol, ethanolamine, or absolute alcohol) should be avoided as they do not control bleeding36 and could lead to life-threatening tissue necrosis.37 Coaptive coagulation can be obtained by the use of bipolar coagulation or heater probes. Perforation rates with these devices range from 0 to 2%, and are increased when treatment is repeated.38,39 Monopolar probes have higher rates of perforation and have largely been abandoned.
Endoscopic tools available to treat esophageal variceal bleeding include band ligation, variceal obliteration, and sclerotherapy. Endoscopic band ligation is as effective as sclerotherapy with fewer and less severe complications (perforation rates: < 0.7 vs. 2–5%; superficial ulceration rates: 5–15 vs. 70–90%, respectively) and a major impact on overall mortality. It has become the preferred technique for acute bleeding, and primary and secondary prophylaxis of variceal bleeding.40,41,42 Injection of cyanoacrylate is more effective than endoscopic band ligation for gastric variceal bleeding but is not without risks, such as embolization, which occurs in 2 to 5% of cases.43 Pulmonary embolism is usually limited and with marginal clinical consequences. Paradoxical embolism may occur (especially in unsedated patients who have transient opening of the foramen ovale) with lethal outcome.
Removal of Foreign Bodies
Adverse event rates encountered during the removal of foreign bodies can reach 8%.44 The most common complication is aspiration pneumonia, which can be prevented by endotracheal intubation, sometimes difficult in an emergency situation. Another major complication is mucosal tearing, which occurs during retrieval of sharp objects through the esophagus. Tearing can be prevented by using a protector hood at the distal extremity of the scope or by the use of an overtube. However, an overtube itself can induce mucosal tearing and perforation of the esophagus. Its use should be restricted to patients placed in the left lateral decubitus position in order to ensure neck overextension during overtube insertion.
10.3.3 Management of Upper Gastrointestinal Perforation
While perforation is a feared and well-known complication of upper GI endoscopy, its management has evolved and is no longer considered an absolute indication for surgery. Endoscopic closure of small perforations (< 2 cm) recognized during the procedure can be achieved using through-the-scope (TTS) clips. Larger over-the-scope closing devices may be useful in selected situations.45,46 SEMSs (partially or fully covered) have also been used to treat large perforations, especially those occurring after dilatation.24,26 An algorithm for the management of upper GI perforation is presented in
In the case of suspected delayed esophageal perforation (characterized by persistent or increasing pain, fever, respiratory distress, and hemodynamic instability), a water-soluble contrast radiographic study is the examination of choice. Alternatively, computed tomography (CT) scan of the neck and chest can be used. Endoscopic closure can be performed in concert with drainage of any fluid visualized collection, when possible.24
In the case of gastric or duodenal perforation, the same principles are applicable, but endoscopic closure mainly relies on the use of clips combined with gastric aspiration.45
10.3.4 Management of Upper GI Bleeding
Bleeding during therapeutic endoscopy is part of the procedure especially during polypectomy, EMR, or ESD. Immediate and late bleeding can be managed using coagulation forceps (preferred during EMR or ESD) or clips. Bleeding occurring after esophageal stenting, especially when occurring late after the initial procedure, should always be evaluated by proper imaging, given the potential risk of esophago-aortic fistulas.48
10.4 Small Bowel Endoscopy
Various endoscopic techniques can be used to explore the small intestine. These include push enteroscopy, single and double-balloon enteroscopy (SBE and DBE, respectively), spiral enteroscopy, and video capsule endoscopy. The most widely available published data concern DBE and video capsule endoscopy. The most common adverse events associated with DBE include perforation, bleeding, pancreatitis, and adverse events related to sedation. The rate of adverse events associated with DBE ranges from 0.4 to 0.8% for diagnostic procedures and 3 to 4% for therapeutic procedures.49,50 The rate of pancreatitis associated with the antegrade DBE is consistently reported to be around 0.3%. The mechanisms of pancreatitis remain poorly understood. Pancreatitis may be prevented by avoiding inflation of the balloon at the duodenal level.51 Management of perforation following enteroscopy usually requires prompt surgical intervention.
Fig. 10.1 Perforation during colonoscopy may occur after polypectomy (a, c) or may be due to direct trauma