Periampullary perforations

Perforation can occur in 0.3% to 1% of ERCPs. Risk factors include sphincterotomy, sphincter of Oddi dysfunction, and dilated common bile duct. Elderly patients tend to have periampullary diverticulum, which can increase the risk of perforations not only by making cannulation more difficult but also by distorting anatomic landmarks used to perform sphincterotomy. Periampullary perforations can be divided into 4 subgroups according to Stapfer and colleagues.

Type I corresponds to lateral or medial duodenal wall perforations, type II peri-Vaterian injury, type III bile or pancreatic duct injury, and type IV the presence of retroperitoneal air alone.

Type I lesions are the result of a countercoup injury with the tip of the scope; they are large and usually require surgical correction with an omental patch, pyloric exclusion, gastrojejunostomy, or other surgical intervention. However, there have been successful cases of endoscopic closure using endoclips or over-the-scope (OTS) clips when the size is less than 15 mm. Clipping using through-the-scope (TTS) mucosal clips can be achieved by placing multiple clips in a linear fashion when the perforation is small and accessible, or with the aid of a transparent cap to suction tissue when angulation is present. Medial wall perforations are more difficult to close endoscopically because of their anatomic location and the risk of clipping the ampulla.

Management of type II injuries is less clear. Treatment is possible using a biliary stent or a TTS clip in addition to the use of a nasoduodenal drain to divert pancreatic and biliary secretions, which are toxic and can lead to clinical decompensation. However, 10% to 43% of patients will require surgical intervention.

Type III perforations are generally easy to treat. Bile duct perforations can be managed by a plastic stent or temporary placement of fully covered self-expandable metal stents (FCSEMS).

Type IV perforations are usually managed conservatively with no surgical intervention, even when large extravasation of air exists in the absence of tension pneumoperitoneum. Pneumoperitoneum can be present in up to 29% of asymptomatic patients who undergo uncomplicated interventions.

Nonperiampullary perforations

Duodenal perforations that are not periampullary are the result of direct trauma to the duodenum from the endoscope or the result of therapeutic interventions such as polypectomies or stricture dilations. Similar to type I perforations, they are mostly managed surgically because of the anatomic difficulty for endoscopic clip deployment. However, TTS clips and OTS clips have been deployed successfully in humans. The use of the FCSEMS is another available option. If retroperitoneal collections develop they can be drained by Interventional radiologists. If blood clots are seen in the drainage catheters the clinician should be suspicious for development of vascular complications such as pseudoaneuvrysms. When hemodynamic instability occurs or endoscopic and interventional radiologic procedures fail, surgical exploration is required.

Colonic perforations

Colonic perforations related to diagnostic colonoscopy are typically due to mechanical trauma secondary to impaction of the endoscope tip, or antimesenteric impaction of the endoscope body against the colonic wall. The sigmoid colon is the most common site of colon perforation owing to its tortuous nature and frequent presence of diverticula, pedunculated polyps, and postoperative adhesions in this region. The rate of perforation in the rectosigmoid colon was reported to be 65%. The descending and ascending colon is the site of perforation in 15% and 8% of cases, respectively. Another area where perforations tend to occur is the cecum. Cecal perforations are induced by barotrauma, typically present in a difficult colonoscopy with overinflation. Perforation rates in the ascending colon and rectum are reported to be equal to that of the cecum, at 4%.

These perforations remain unrecognized until pneumoperitoneum develops. When it occurs, needle decompression should be performed to eliminate tension pneumoperitoneum. Further management depends on the clinical status of the patient, the size of the perforation, the presence of extraluminal fecal soiling, the degree of colon preparation, and the time elapsed after the perforation. When the perforation is recognized during or immediately after the procedure, closing with TTS clips or OTS clips should be attempted when the perforation is less than 2 cm. Band ligation can also be useful for closing colon perforations that fail placement of TTS mucosal clips. It is recommended to close vertical perforations from the top down and horizontal/circular perforations from left to right.

A new innovative approach to close colonic perforations, termed the tulip bundle technique, has been described, which requires an endoloop, TTS clips, and glue. Clips are positioned on the perforation edges, followed by tightening of the defect with an endoloop and applying glue to their bases to complete the closure.

Colonic perforations related to therapeutic colonoscopic interventions differ in mechanism from those caused by diagnostic colonoscopy. More frequently localized to the cecum and right-side colon, transmural electrocautery injury is the leading cause of perforation. For example, during polypectomy the identification of a target sign on the excision site and on the specimen indicates perforation, and should be closed endoscopically immediately.

It is very important to monitor patients closely for any deterioration that would require surgical intervention. Abdominal computed tomography (CT) with rectal contrast can help identify continuous leakage. If a collection is identified, it should be drained. When colonic perforations open into the peritoneal space, surgical exploration with washout and fecal diversion is recommended. Perforations isolated to the extraperitoneal space generally can be treated nonoperatively.

Rectal perforations

Causes of rectal perforation include endoscope retroflexion, endoscopic mucosal resection, and ESD. Rectal perforation is diagnosed by direct or radiographic visualization of evidence of unintended penetration beyond the rectal mucosa. Typically these perforations are moderate, and lead to subcutaneous emphysema that is treated by nothing per mouth and broad-spectrum antibiotics. These emphysemas usually resolve in a matter of days. Defect closure using TTS clips and OTS clips can be effective.