The main complication of video capsule endoscopy is capsule retention (frequency 1–2%).52 Retention is more common in cases of stenosis, especially those associated with Crohn’s disease. The identification of a radiological abnormality of the small bowel is associated with a risk of capsule retention of 15.4%, usually requiring surgical or DBE exploration for retrieval.53
10.5 Colonoscopy
Colonoscopy is the gold standard for diagnosis of colorectal cancer and treatment of colorectal polyps. The rate of significant adverse events for diagnostic colonoscopy ranges from 0.02 to 0.07%.54 The bowel preparation itself, if performed with sodium phosphate, may be associated with hypovolemia, hyperphosphatemia, and eventually death. Age, preexisting renal failure, and the use of nonsteroidal anti-inflammatory drugs (NSAIDs) are risks factors for this complication.55
10.5.1 Perforation
The reported frequency of this most feared complication varies in the literature. In a multicenter, prospective survey of 9,223 colonoscopies performed in England, the perforation rate was 0.11% for diagnostic and 0.21% for therapeutic colonoscopy.54
Three different mechanisms exist by which colonic perforation might occur during endoscopy: pneumatic perforation of an already weakened colonic wall; mechanical perforation owing to excessive pressure by the scope against the colonic wall; and posttherapeutic colonoscopy perforation, which can occur when the colonic wall has been made fragile by polypectomy, EMR, ESD, and/or coagulation during therapeutic colonoscopy. Following the results of a report of 183 colonic perforations, the most predominant site of perforation was the sigmoid colon (72%), followed by the ascending and descending colon (8.6% each), the rectum (6.9%), and the transverse colon (3.4%).56 Risks factors for perforation during colonoscopy include the following: therapeutic colonoscopy (polypectomy, EMR, stricture dilation, and argon plasma coagulation use), age > 75 years, diverticular disease, previous intra-abdominal surgery, colonic obstruction, and female gender.57
Intraprocedural perforations occurring during EMR or ESD (the latter in approximately 30% of cases)58 are frequently recognized immediately, with the “target sign” on the resection specimen useful. EMR perforation risk factors include transverse or right colon location, en-bloc resection, and presence of high-grade dysplasia or submucosal cancer in the resected specimen.59 In most situations, the recognition of peritoneal structures is obvious, but a sudden lack of insufflation and/or acute pain are signs that perforation has occurred.56 In half of cases, perforations are < 2 cm in length and are not easily recognized. This is why, the diagnosis is often delayed (from 1 hour to weeks after the procedure).56 An overt perforation with associated peritonitis is easy to diagnose, while patients having localized peritoneal signs due to minimal perforation, sometimes delayed and known as “the postpolypectomy syndrome” or “transmural burn syndrome,” may be more challenging to diagnose. The clinical outcome of postpolypectomy syndrome is usually favorable with conservative treatment.58 In any case of suspected perforation, an abdominal CT scan is the preferred examination for differentiating colonic perforation from postpolypectomy syndrome, which is characterized by the absence of diffuse air leak.
10.5.2 Management of Colonic Perforation
Owing to the frequency and diversity of perforation types (mechanisms, size, and location), management remains controversial (
Although most patients with colonic perforation require surgical intervention, some can be effectively managed conservatively, especially if the endoscopist is able to close the perforation endoscopically.65,66 The efficacy of clipping, in terms of intention to treat, is not fully determined; a review of 75 cases revealed a success rate ranging from 69 to 93%, without mortality in patients in whom endoscopic closure was achieved,66 but these values are probably overestimates. Key factors for endoscopic success are small perforations (<2 cm), early recognition, a clean bowel, and prompt and complete closure.67 Over-the-scope clips, such as the OVESCO (Ovesco Endoscopy, Germany), are being used with favorable results. A recent systematic review of all iatrogenic GI perforations reported clinically successful endoscopic closure in 90% using standard clips and 88% using over-the-scope clips.45 Although this likely does not represent a true comparison, it stresses the fact that, at least in the colon, standard TTS clips remain the first choice.59 Prospective randomized studies are needed to define the role of various techniques of endoscopic closures. When endoscopic treatment of a perforation is foreseen, CO2 insufflation (if not already used) should be immediately instituted and special attention given to a possible drop in blood pressure related to a decreased cardiac preload induced by intraperitoneal hypertension. Prompt peritoneal decompression should be performed by needle puncture. Conservative treatment consists of bowel rest, intravenous hydration, administration of broad-spectrum antibiotics, and close clinical monitoring. Successful closure is noted by clinical improvement within the first 48 hours. Such an approach can be considered for all patients who are in good clinical condition with localized symptoms of peritonitis and in whom the perforation is contained, either by endoscopic closure or by spontaneous sealing.67,68
Fig. 10.2 Intrarectal indometacin must be administered before any procedure performed on an intact papilla. High-risk patients (acinarization [a], multiple manipulations on a normal pancreas) may benefit from additional prevention of pancreatitis with PPS. If a guidewire is inserted into the pancreas, it can be left in place and may facilitate further biliary cannulation (b). At the end of the procedure, it is used to insert a PPS (5Fr, without proximal flaps) (c).
Surgical treatment is standard for patients with generalized peritonitis and/or objective failure of endoscopic closure, in patients who deteriorate under conservative treatment, and finally in patients presenting with colonic disease that otherwise requires surgery (such as colon cancer). Simple closure of the perforation is often possible in the absence of intraperitoneal fecal contamination; resection with immediate intestinal anastomosis and colectomy with temporary colostomy are alternatives.
The outcomes of patients with colonic perforation requiring surgery are associated with morbidity and mortality rates of 21 to 53% and 0 to 26%, respectively.57,58,68 Surgical site infection is frequent, and leading causes of death are cardiopulmonary complications and multiple organ failure.57,58
10.5.3 Bleeding
Bleeding is the most frequent complication after polypectomy (incidence: 0.3–6.1%).69,70 There is no evidence that aspirin or NSAID use increases the risk of bleeding after mucosal biopsy or polypectomy.71 However, the reader is referred to national societal guidelines concerning the management of anticoagulation and antiplatelet agents during endoscopy.5 The risk of bleeding depends on the type and size of the polyp and the technique of polypectomy.
Immediate bleeding occurring during endoscopy (1.5% of cases) must be differentiated from delayed bleeding occurring from a few hours to 1 month after polypectomy (2% of cases). In most cases, persistent active bleeding can be managed endoscopically using endoscopic hemostatic tools, such as snaring of residual stalks for compression,