Utility of endoscopic retrograde cholangiopancreatography in management of pediatric pancreaticobiliary disease

The use of diagnostic and therapeutic endoscopic retrograde cholangiopancreatography (ERCP) is steadily increasing in the management of pancreaticobiliary diseases in children [1]. While magnetic resonance cholangiopancreatography (MRCP) is one of the diagnostic imaging modalities available for detecting anatomical abnormalities, MRCP images cannot fully identify anatomical abnormalities in pediatric patients. Therefore, there is a need to identify the scope and utility of ERCP in children with pancreaticobiliary diseases.

We previously performed ERCP in asymptomatic patients with congenital biliary dilatation (CBD) to ascertain anatomical details [2, 3]. Of late, however, ERCP is performed only in symptomatic CBD patients for therapeutic purposes, so as to avoid associated complications.

In addition to CBD, ERCP is also performed for the treatment of choledocholithiasis and for the investigation and treatment of unexplained pancreatitis.

The etiologies of pediatric pancreatitis include drugs, infections, trauma, and anatomical abnormalities. In Japan, Suzuki et al. reviewed 145 pediatric patients with acute pancreatitis and reported that 54.5% of cases were caused by anatomical abnormalities [4]. For patients with unexplained pancreatitis, ERCP and endoscopic transpapillary therapy have been performed as required to detect anatomical abnormalities. The purpose of this study was to evaluate the utility of ERCP in pediatric patients with pancreaticobiliary diseases.

This study was approved by the ethics committee of our institution (#2020 − 0635).

Because this was a retrospective observational study and the data analyzed were anonymized, informed consent from participants or their parents/guardians was obtained through an opt-out method on our hospital website in accordance with the Ethical Guidelines for Medical and Health Research Involving Human Subjects in Japan. A retrospective review was performed concerning patients who underwent ERCP for the treatment of biliary tract disease and detailed investigation of the cause of pancreatitis at our institution, from January 1999 to December 2020. Our current treatment strategy for preoperative management of CBD is shown in Fig. 1. Extrahepatic bile resection was performed within 1 month after stenting. The strategy for pancreatitis suspected to be caused by anatomical abnormalities is shown in Fig. 2. ERCP for symptomatic CBD was performed as early as the regular examination schedule permitted after referral to our institution, while ERCP for pancreatitis was scheduled once the clinical symptoms of pancreatitis improved; in both instances, the procedures was performed under general anesthesia. Pancreatitis was defined as the presence of abdominal pain with hyperamylasemia and inflammation. All endoscopic procedures were performed by trained gastroenterologists. For endoscopy, PJF-7.5 (tip outer diameter, 7.8 mm; channel diameter, 2.0 mm; Olympus) and JF-240 (tip outer diameter, 12.6 mm; channel diameter, 3.2 mm; Olympus) were used for infants and school-age children, respectively. The endoscope was selected depending on the body size of the patient and the procedure to be performed. PJF-7.5 was used only for contrast and stent tube insertion. We selected JF-240 for papillotomy since it allowed us to deliver various devices. Endoscopic pancreatic stenting (EPS) was performed for flexion, stenosis, and dilatation of the pancreatic duct to prevent pancreatitis. Stent replacement was performed every three to six months after EPS. Endoscopic transpapillary therapy (stent tube insertion or papillotomy) was attempted when drainage of the bile duct or pancreatic duct drainage was deemed necessary.

Over the 22-year observation period, ERCP was performed in 52 patients for the treatment of biliary diseases, and in 13 patients for the examination and treatment of pancreatic diseases. These patients comprised 24 boys and 41 girls with an age range of 3 months to 14.8 years (median 4.8 years). We have successfully performed ERCP on a child as young as 3 months and 5 kg.

ERCP appears to be technically difficult and challenging in children because of their narrow airways and smaller anatomical dimensions compared to adults [5]. Improved designs of endoscopes and associated accessories have facilitated the development of ERCP procedures in children [1]. We found that diagnostic and therapeutic ERCP procedure could be successfully performed in childhood, even at three months of age. The only severe complication noted after ERCP was common bile duct injury; there were no cases of severe pancreatitis, bleeding, or perforation.

Our complication rate 1.5% (1/65) was lower than 7.7% incidence typically reported in pediatric large case series [6, 7]. Pediatric ERCP was performed by the most skilled gastroenterologist in our institution, and the use of PJF-7.5 (tip outer diameter, 7.8 mm; channel diameter, 2.0 mm; Olympus) may have avoided unnecessary pressure on the pancreatic duct and thus avoided post-ERCP pancreatitis.

Endoscopic biliary drainage with a temporary stent is adequate for symptomatic relief of CBD. We previously reported that endoscopic short-tube stenting is beneficial in children because it does not require tube management [3]. In our present study, ERCP for biliary tract disease was highly successful and effective. Four patients had unsuccessful stenting, but one patient had symptomatic improvement with guidewie manipulation. Thus, three (5.8%) of the 52 biliary disease cases failed to be treated by ERCP owing to difficulties encountered in cannulation, when the narrow segment was right-angled, or the body size of the patient was too small for the procedure. Percutaneous transhepatic biliary drainage may be useful when stent tube placement is unsuccessful. It has been reported that early biliary decompression should be performed when symptoms persit, but no definite protocol has been established [3, 8]. It is not necessary to perform ERCP in all symptomatic CBD patients, as symptoms may improve with fasting alone. Although there is certainly no statistical evidence to suggest the usefulness of our current treatment strategy for preoperative management of CBD (Fig. 1), our strategy is very safe and effective in carefully selecting patients for ERCP with few complications and safe surgery.

In this study, patients who underwent ERCP for determination of the cause of and treatment for pediatric pancreatitis were also evaluated. ERCP was useful for understanding pancreatic duct anatomy. MRCP can reportedly be evaluated in the same way as ERCP [9]; however, in our experience, the images were unclear and difficult to evaluate. ERCP evaluation in children should be strongly considered because minor artifacts, as seen on MRCP, make evaluation difficult.

We reported four cases of pancreatitis after congenital duodenal atresia/stenosis surgery. Duodenal atresia and stenosis are often accompanied by pancreaticobiliary anomalies due to developmental reasons [10‐12]. Growth may also lead to impaired pancreatic drainage due to ductal angulation. Detailed examination of pancreatitis after duodenal atresia associated with an annular pancreas can lead to the diagnoses of pancreaticobiliary maljunction, pancreas divisum, and CBD requiring surgical treatment in some patients [10‐12]. Since a wide variety of anatomical abnormalities have been observed, there is a need to carefully search for underlying causes and to develop treatment strategies for pancreatitis after congenital duodenal atresia/stenosis surgery. In Case 2, a pancreatic duct stent was emplaced because the Wirsung duct was bent, and in Case 3, a pancreatic duct stent was placed in the dominant dorsal duct from the accessory papilla. These results suggested that stenting of the pancreatic duct should be useful for improving the angulation and drainage of the pancreatic duct.

In our study, EPS for chronic pancreatitis improved the stenosis that had caused acute exacerbations and, eventually, patients were followed up after repeated stenting without recurrence of pancreatitis. Endoscopic treatments for chronic pancreatitis have been reported to be effective, and favorable results have recently been reported with EPS [5, 13]. EPS can be performed safely even in pediatric patients, and is often the first choice for endoscopic treatment.

In addition, the indications for endoscopic minor papilla sphincterotomy can be decided by placing a pancreatic duct stent in patients with pancreatic divisum and setting the follow-up period. Endoscopic minor papilla sphincterotomy encompasses risk for certain complications such as perforation, bleeding, and acute pancreatitis, and incomplete incision may result in scar stenosis and impaired drainage [14]. Since there is no evidence recommending the direction and extent of the incision, the policy adopted at our institution is to consider minor papillotomy in patients aged 2 years or older (the JF-240 body size that allows the endoscope to be inserted). Thus, the indications for papillotomy should be carefully considered. These experiences suggest that our diagnosis and treatment strategies for pancreatitis in children (Fig. 2) are effective.

In conclusion, ERCP and transendoscopic therapy are sufficiently feasible in pediatric patients and should be actively introduced for the investigation and treatment of pancreaticobiliary diseases.