In this study, we investigated the incidence rate of duodenal perforation among patients undergoing ERCP and compared patients’ and procedure’s characteristics to a control group. Our results revealed that perforations occurred in a comparable rate (1.34%) to published series. Our study also disclosed that failure to cannulate the CBD was the main predictor of perforation during ERCP.
The reported incidence of ERCP related perforations varied between 0.11% and 2.4%6 [7]. In one large analysis of 21 prospective surveys of post-ERCP complications in adults (16,855 patients) between 1977-2006, 101 patients experienced perforation (0.60%). The mortality rate in that study was 9.9% [3]. In another review of 18 (mainly retrospective) studies conducted between 2000-2014, the incidence rate of EIP was 0.39%, with an overall mortality of 7.8% [8]. Surprisingly, published numbers did not seem to decline significantly over the last 20 years as ERCP became more popular and widely available.
Published data revealed that the incidence rate of ERCP perforations corresponds with volume of cases at each institution, as highest volume centers (which perform more than 1000 ERCPs per year) reported lower incidence rates (Bill et al. 0.44%, Jin et al. 0.27%, Kim J et al. 0.61%, Howard et al. 0.6%, Dubecz et al. 0.09%) [9–13], compared to the lower volume ones (less than 500 ERCPs per year) (Turner et al. 2.4%, Stapler et al. 1%, Miller et al. 1.65%, Rabie et al. 1.67%, Koc et al. 0.94%) [5, 6, 14–16]. The correlation between incidence of perforation and volume of ERCP cases needs further analysis to elaborate statistical significance. These observations, however, indicate that ERCP remains an invasive procedure which may carry significant morbidity and mortality, even in skilled hands or at high volume units.
“Difficult cannulation” is a term employed to describe failure to gain access into bile duct by the conventional cannulation technique. Factors that may contribute to this difficulty include presence of periampullary diverticula, altered anatomy and bulky papilla. In many studies, this situation has been defined as a leading cause of perforation [17]. The risk is highest as precut papillotomy (or sphincterotomy) is attempted by the endoscopist to overcome this challenge. In Vezakis et al. review, endoscopic sphincterotomy was responsible for 41% of perforations [8]. Another study by Stapfer and colleagues found that cannulation of the ampulla was considered difficult by the endoscopist in 10 of 14 patients who had perforations (out of 1413 ERCPs) [5]. In their review of 21 prospective reports of ERCP complications, Andriulli et al. found that the overall complication rate was significantly higher whenever therapeutic interventions were utilized during ERCP [3]. Complications were also significantly higher in studies with a precut sphincterotomy rate of over 10%. Fifty years after the advent of therapeutic ERCP, difficult cannulation is still a condition that is frequently encountered, which may –although rarely- predispose to perforation and subsequent morbidity and death.
There appears to be a consensus on electing surgery for the treatment of free duodenal wall perforations (type I), which commonly present with signs of peritonitis [12, 18–20]. In our group of patients with perforation, surgery was required in 5/13(38%), 4/5 of the operated patients had type I (free wall) perforation. Surgical intervention is conducted in higher risk injuries that are more likely to progress into sepsis, which explains –in part- the higher morbidity observed in this subgroup. Because duodenal or duct wall defect identification during surgery might be very challenging, especially if diagnosis is delayed (>6 hours post ERCP) [21, 22], surgery can be limited to perform proper drainage and debridement of unhealthy tissue, which can reduce the risk of systemic manifestations and sepsis. Diversion surgeries (Roux-en-Y bypass) have been reported in management of large duodenal perforations [5]. However, in ERCP most perforations are small, unless caused by the scope itself.
Endoscopic repair of duodenal perforations, particularly small defects(<10mm) that are recognized during ERCP has been reported [23, 24]. The latter development of endoscopic clipping (through-the-scope clips), suturing and closure devices (ligation band, fibrin glue, and endo-loops) as well as covering luminal stents has made endoscopy more efficient in treating injuries similar to perforations and bleeding [25–31]. With the growing body of evidence supporting the use of these techniques for the management of ERCP complications, endoscopist expertise, perforation type and diameter remain important predictors of the outcomes.
In other types of perforation, i.e. types I, II and IV, the injury is less likely to manifest as peritonitis, but rather as retroperitoneal (and to a less extent intraperitoneal) fluid or air accumulation. Conservative measures in such circumstances vary from simply restricting oral intake with parenteral nutrition, hydration and coverage with broad spectrum antibiotics to percutaneous drainage of collections under ultrasound or CT guidance.
It is critical to recognize if leakage has stopped after the endoscopy or still ongoing, as the patient may have experienced transient fluid extravasation during the procedure due to duct or duodenal wall puncture. The presence of enlarging pockets of pus or fluid collections, especially in the retroperitoneal space, does not necessarily indicate an active leakage, which can usually be excluded utilizing CT scan with water soluble contrast (Gastrografin), or fluoroscopic imaging (meal). This may instead indicate inadequate drainage or persistent infection that mandates repositioning of the drain, upgrading the size of the drain or placing another drain. It may also be helpful to consider adding antifungals after submitting samples for cultures.
The following are literature-based guidelines which can be driven to conclude when and how to intervene in patient with suspected or proved ERCP-induced perforation;
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Suspicion is raised whenever cannulation is difficult, the threshold for obtaining a post ERCP CT scan to exclude perforation has to be lowered, since early detection may improve outcomes.
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Active intraperitoneal contrast extravasation from duodenal wall on CT scan is considered a reasonable indication for prompt operative exploration.
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The main target of surgical exploration is to control sepsis by drainage of accumulated fluids. Repair of the defect, if identified, is another target with special attention to prevent occlusion of the ducts.
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The presence of free fluids inside the peritoneum or in the retroperitoneal space is an indication for drainage, this can be achieved by interventional radiology (IR) under CT scan or ultrasound guidance, or by surgery if IR service is not available or the collection is not accessible.
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Most of bile duct perforations can be managed by internal biliary stents, along with drainage of any collection. External nasobiliary drainage is considered a valid alternative for internal stenting.
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Failure of non-operative measures, which can be defined as the persistence of abdominal sepsis (significant pain, tenderness and ileus), as well as fever and continuous elevation of inflammatory markers (leukocytes, CRP, ESR, etc.), indicates prompt conversion into surgical approach.
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Prolonged restriction of oral intake may not be of any help if there is no evidence of an ongoing leakage.
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ERCP perforation remains an event that has to be approached by both surgeons and endoscopists.
This study has some limitations. Firstly, it is a retrospective study. Secondly, the sample size of patients with EIP was relatively small to evaluate risk factors with statistical significance. Thirdly, we assume that a small group of patients with type IV perforation may have not been detected, due to lack of abdominal or systemic manifestations.
In conclusion, fifty years after introduction of ERCP for therapy, it remains an invasive procedure which may carry significant morbidity and mortality, even in skilled hands or at high volume units. Selection of patients for ERCP must be strict, it has to be done for therapeutic indications. Difficult cannulation is still a condition that is frequently encountered, and considered the main risk factor for perforation. Early diagnosis and appropriate surgical or percutaneous drainage yield favorable outcomes.