Frequency and Causes of Failed Endoscopic Retrograde Cholangiopancreatography in AL-Rajhi Endoscopy Unit

• This analysis included 200 patients who underwent ERCP for different indications. Failure occurred in 28 patient (14%).
• Most cannulation failure was noted in patients with malignant obstruction, abnormal papillary variation; followed by altered anatomy with previous surgery.
• Additional predictors of failure were endoscopists’ experience < 5 years and higher body mass index.
• When ERCP failed to achieve drainage a second trail of ERCP within 3-7 days can be usueful, however definite management was percutaneous transhepatic drainage, surgical intervention and rendezvous technique.
• To overcome difficulties in Papillary cannulation early pre-cut fistulotomy may be preferable. In cases of frequent unintentional PD cannulation, double guidewire induced cannulation, trans-pancreatic pre-cut with the guidance of a guidewire as well as a pancreatic stent may be useful.
• Further clinical trials, training unification and clinical guidelines are needed to minimize procedure failure.

Table 1. Baseline data of the studied patients based on outcome of cannulation.

Despite advances and new developments in endoscopic accessories, selective biliary access fails in 5%-15% of cases, even in expert high volume centers. Various techniques, such as double-guidewire induced cannulation, pre-cut papillotomy, or transpancreatic sphincterotomy with or without placement of a pancreatic stent — have been used to improve cannulation success rates [10].

In the current study aimed to assess the frequency of failure of biliary cannulation during the procedure of ERCP and determine its possible risk factors. A total of 200 patients underwent ERCP were enrolled in the study at Al-Rajhi University Hospital between January 2020 and January 2021.

Out of those patients, successful papillary cannulation was achieved in 172 (86%) patients while in the other 28 (14%) patients, cannulation failed. This was consistent with previous reports about selective biliary access failure that may reach up to 5%—15% of cases, even in expert high volume centers [10].

In the current study, predictors of failed cannulation of major the papilla were endoscopists’ experience < 5 years (odd’s ratio= 2.50) and malignant obstruction (odd’s ratio= 4.55). Cotton et al. stated that the likelihood of successful cannulation is influenced by operator factors (experience) and patient factors (anatomy). Expert endoscopists are expected to be successful at biliary access in 95% to 100% of attempts, a goal that is supported by literature. Community success rates should exceed 90% [11].

In agreement with this study, two studies reported that a direct association between the case volume, local expertise, endoscopic training, and practice setting [12, 13]. Also, Cotton et al. and Lehman et al. reported that trainees are deemed competent to perform endoscopic procedures independently when a success rate of 80% to 90% is achieved [11, 14].

The current study stated that failed cannulation had a significantly higher frequency of complications. Thirteen patients (7.6%) and 3 (1.7%) patients with successful cannulation reported pancreatitis and bleeding, while pancreatitis, bleeding and duodenal perforation were reported in 10 (35.7%), 1 (3.6%) and 2 (7.1%) patients with failed cannulation, respectively

The increase in risk related to these technical aspects very likely depends on the fact that pre-cutting generally follows a number of failed cannulations attempts in a lengthy procedure. The risk of post-ERCP pancreatitis further increases with difficult cannulation in patients at high risk for this complication because risk factors have been shown to be independent in multivariate analysis so they might have a cumulative effect [15-17].

Also, the most frequently reported causes of failure were abnormal variation in papilla (53.6%) and infiltrated papilla (28.6%) followed by altered anatomy with previous surgery in 4 (14.3%) patients and large juxa-papillary diverticulum in one patient. Management of those patients was percutaneous transhepatic drainage (35.6%), second trail of ERCP (32.2%), surgical intervention (17.9%) and rendezvous technique (14.3%).

It’s known that when selective biliary access is difficult, despite frequent meaningful contact with the papilla or prolonged cannulation times without unintentional pancreatic duct cannulation, an early pre-cut fistulotomy may be preferable. In cases of frequent unintentional PD cannulation, double guidewire induced cannulation, transpancreatic pre-cut with the guidance of a guidewire as well as a pancreatic stent may be useful [18].

Haraldsson et al. studied a total of 1401 patients underwent ERCP with overall frequency of failed cannulation was 2.8%. The authorsstated that although the frequency of difficult cannulation among the different types in papilla variations was based on skill level, but the overall frequency of difficult cannulation regardless of papilla type was 42% in their study [19].

The study by Haraldsson et al serves as a reminder that anatomic differences in the shape and appearance of the major papilla can affect outcomes during ERCP. This information can potentially help with decision making during the procedure, but regardless of the type of papilla encountered, deep biliary cannulation is still the criterion standard for success [19].

When biliary cannulation fails, other classical techniques, such as radiologic and surgical approaches, may be used to access the bile duct. One recently proposed approach after a failed cannulation is to transform ERCP to an endosonography-guided cholangiopancreatography during the same session. These alternative techniques are more invasive than ERCP and may entail greater morbidity rates [7].

Here, in this study, we noticed that a second trial of ERCP was done in 9 (32.2%) patients with failed first trial of cannulation. The second trial was done within 4-7 days from the first trial, and all of them were successful. Kim et al. state that repeating ERCP a few days after the initial precut failure often reveals an open and easily accessible papilla, allowing cannulation in up to 85% of cases. Furthermore, this second ERCP within days also seems safe [20].

In spite of the efficacy and safety of a second ERCP, however, risk factors associated with this strategy have not been specifically assessed. Additionally, the precut technique used differs widely among endoscopists and institutions, and data assessing the success of a second ERCP are limited to single-center studies [20-22].

Based on the currently available data in the literature, the application of a stepwise algorithm rather than a single technique is needed to facilitate biliary access during ERCP without increasing complications. Several studies have demonstrated that repeating the ERCP within a few days after initial failed pre-cut is a successful strategy and should be tried before contemplating more invasive, alternative interventions [7, 21].

Percutaneous transhepatic biliary drainage is the conventional alternative method in patients who fail ERCP. However, percutaneous transhepatic biliary drainage is associated with high morbidity and can lower patients’ quality of life. It may also be difficult to carry out when the intrahepatic bile ducts are not dilated. ERCP occasionally fails because of surgically altered anatomy, gastric outlet obstruction, periampullary diverticulum, indwelling duodenal stent and large tumors [20].

In cases of failed cannulation in surgically altered anatomies, balloon enteroscopy-assisted ERCP is an alternative that has shown high technical and clinical success in specialized centers. Other procedures can be used as endoscopic ultrasound and percutaneous endoscopic rendezvous (PE-RV) may be preferred [23, 24].

The main limitations of the current study are being conducted in single center, relatively small sample size, no long term follow up of cases with failed trail of papillary cannulation. Yet, this study was the first study to discuss such an issue in our locality.

CONCLUSION

Frequency of difficult biliary cannulation is highly variable among different studies. Based on the current study, the most frequent risk factors for such issues were decreased endoscopist experience and malignant biliary obstruction leading to distorted anatomy. Efforts should be directed toward a standard simple documented definition for the selective biliary cannulation and clear reporting of failure or complications.

The Authors declare no conflict of interest or obtained any funding for this study.

Ethical considerations: This study was performed in line with the principles of the Declaration of Helsinki.