Acute pancreatitis is caused by various etiologies, although the pathogenic mechanisms are not fully understood [1]. The causes of acute pancreatitis are broadly categorized as obstruction, toxin, trauma, metabolic abnormalities, and infection. Iatrogenic pancreatitis occasionally develops from endoscopic retrograde cholangiopancreatography (ERCP), endoscopic sphincterotomy, or manometry of sphincter of Oddi [2-7]. However, acute pancreatitis after the insertion of a percutaneous transhepatic cholangiography (PTCS) catheter has not been previously reported. Hence, we report a case that presented with acute pancreatitis resulting from the obstruction of the main pancreatic duct due to compression by a stiff catheter and large stones in the common bile duct (CBD) following the insertion of a PTCS catheter.

A 65-year-old woman presented with postprandial epigastric pain that lasted for several days. Twenty years ago, the patient had undergone a subtotal gastrectomy with Billroth II for gastric ulcer and a cholecystectomy. Vital signs were stable. Tenderness of the epigastrium and right upper quadrant of the abdomen were observed in the physical examination. Results of laboratory examinations showed that white blood cell count was 4,050/mm³, aspartate transaminase was 1,035 IU/L, alanine transaminase was 824 IU/L, total bilirubin was 2.4 mg/dL, alkaline phosphatase was 1,343 U/L, and gamma-glutamyl transpeptidase was 342 U/L. Abdominopelvic computed tomography (CT) exhibited multiple large stones in the dilated CBD and left intrahepatic duct (Fig. 1A). The size of the largest CBD stone was about 3 cm. The patient was diagnosed with acute cholangitis due to multiple CBD stones. Antibiotics and stone removal were considered to treat the cholangitis. Percutaneous transhepatic biliary drainage (PTBD) was planned to resolve the biliary obstruction because of altered anatomy after subtotal gastrectomy with Billroth II anastomosis. A PTBD (8.5 French [Fr]) catheter was inserted through the left intrahepatic duct (Fig. 1B). PTBD catheter (Sung Won Medical Co., Ltd, Cheongju, Korea) is made from polyurethane. After one week, the PTBD tract was dilated using a 14-18 Fr dilator (Cook Medical, Bloomington, USA) in sequence. The tip of the 18 Fr PTCS catheter was located in the distal CBD across the large CBD stones. PTCS catheter (Akita Sumitomo Bakelite Co. Ltd, Dongguan, Japan) is made from polyvinyl chloride (Fig. 2). After insertion of the PTCS catheter, the CBD was straightened and the large stone was pushed to the medial side of CBD (Fig. 1C). The patient was discharged after tract dilatation, and PTCS was scheduled for two weeks later. However, the patient visited the emergency room for severe abdominal pain three days after discharge. Vital signs were stable. Laboratory examinations were as follow: aspartate transaminase 40 IU/L, alanine transaminase 41 IU/L, gammaglutamyl transpeptidase 156 IU/L, total bilirubin 0.5 mg/dL, amylase 3,394 IU/L, and lipase 2,965 IU/L. Abdominopelvic CT demonstrated diffuse swelling of the pancreatic head, dilated main pancreatic duct, and peripancreatic infiltration. A small amount of fluid collection was also observed in the anterior of pararenal space. Large CBD stones were located at the medial side of the pancreatic head and a PTCS catheter was inserted at the lateral side of the pancreas. Due to abdominal pain, elevated pancreatic enzymes, and radiologic abnormalities, the patient was diagnosed with acute pancreatitis. However, the main pancreatic duct showed slight dilatation on the CT scan, before insertion of a PTCS catheter (Fig. 3A). We confirmed that a huge stone was pushed to the pancreas by the stiff PTCS catheter, and the main pancreatic duct was dilated definitely following the compressed site formed by the stone (Fig. 3B). Other causes of acute pancreatitis, such as alcohol, drugs, and metabolic abnormalities, were excluded. Therefore, the cause of acute pancreatitis was attributed to the obstruction of the pancreatic duct after the insertion of the PTCS catheter which did not pass through the Ampulla of Vater (AOV). The catheter was repositioned about 3 cm back in order to resolve the compression of the main pancreatic duct. Abdominal pain and blood tests were improved after withdrawal of the PTCS catheter and conservative treatment. Follow-up CT revealed improvement of the dilation of the main pancreatic duct after one week (Fig. 3C). After confirming the improvement of the pancreatitis, PTCS was performed. All CBD stones were removed during two sessions of PTCS. Although balloon dilations of AOV and the reinsertion of the PTCS catheter in the distal CBD were performed, there was no recurrence of acute pancreatitis.

Acute pancreatitis is defined as acute and sudden inflammation of the pancreas. It is caused by various etiologies including gallstone, alcohol, hypertriglyceridemia, and anatomic abnormalities [2]. Moreover, iatrogenic pancreatitis can be caused by traumas induced by ERCP, endoscopic sphincterotomy, manometry, or surgery. PTCS is done in order to promote biliary drainage and to remove intrahepatic and CBD stones by using a flexible choledochoscope. PTCS is performed after insertion of a PTBD catheter and serial dilatation of the percutaneous transhepatic tract. PTCS has been associated with rare complications of the pancreatic system, if it does not perform the manipulations of AOV. In particular, there has been no report about acute pancreatitis following the insertion of a PTCS catheter. However, some cases of acute pancreatitis related percutaneous transhepatic biliary intervention have been reported [8-11]. In these reports, acute pancreatitis developed only in cases with stent or catheter insertion across the AOV. There was no acute pancreatitis without manipulation of AOV. It has been generally accepted that injury of AOV by mechanical stimulation and the obstruction of pancreatic duct by the inserted catheter or stent are the causes of acute pancreatitis.

In our patient, there was no cause for acute pancreatitis, such as alcohol, drugs, or metabolic abnormalities, except for PTCS catheter insertion. The PTCS catheter and large CBD stones were impacted in the narrow CBD and pressed the pancreatic head portion, although the catheter was not placed across the AOV. It suggests that PTCS catheter may have the own space in the narrow CBD and may shift the expansile force toward the pancreas than soft PTBD catheter. As a result, the stiff PTCS catheter and huge stones make a force toward the pancreatic head portion, which may raise obstruction of the main pancreatic duct following the compressed site. Actually, the definite upstream dilation of the main pancreatic duct was observed following the compressed area of the large CBD stone which was pushed by PTCS catheter. In order to resolve the pressure of the main pancreatic duct, the catheter was repositioned back about 3 cm. The compressed site of the CBD stone and catheter may be changed after withdrawal of the catheter, and the pressure of the main pancreatic duct was decreased. Acute pancreatitis was improved because of decompression of the pancreatic duct and conventional therapy. Moreover, there was not another event of acute pancreatitis, though manipulations of AOV and reinsertion of the PTCS catheter during two sessions of PTCS. For these reasons, acute pancreatitis of this patient was regarded as a complication that was induced by the compression of the main pancreatic duct by the catheter and large stones in the CBD. There was no report associated with catheter induced pancreatitis that was not associated with manipulation of AOV, although cases of acute pancreatitis due to distal biliary manipulation such as stent and catheter across the ampulla have been reported. However, we ascertain that acute pancreatitis can be caused by compressing the main pancreatic duct when an instrumental device is inserted within the narrow space of CBD. Therefore, diagnosis of acute pancreatitis should be attempted when the patient has new or worsened abdominal pain after the insertion of the instrument in CBD [12].

In conclusion, we suggest that an inserted instrument, such as a PTCS catheter, should be considered as a probable cause of acute pancreatitis, as the catheter and stones can obstruct the pancreatic duct. Further studies will be required to determine the prevalence and risk factors. Owing to the potential for fatal clinical deterioration, clinicians should be alert to the possibility of acute pancreatitis.