Yoshiaki Kawaguchi

We encountered a very rare case of bile duct carcinoma associated with congenital biliary dilatation (CBD) in a 16-year-old female who was admitted to our hospital because of right upper abdominal pain and vomiting. Abdominal computed tomography demonstrated a cystic dilatation of the common bile duct measuring 7 cm in diameter and two enhanced tumors 4 cm in diameter located in the inferior bile duct and middle bile duct. Magnetic resonance cholangiopancreatography clearly demonstrated a cystic dilatation of the extrahepatic bile duct (Todani’s CBD classification: type 4-A). Endoscopic retrograde cholangiopancreatography also revealed two tumors. Biopsy results of one of the tumors confirmed adenocarcinoma. Excision of the perihilar bile duct and subtotal stomach-preserving pancreaticoduodenectomy with dissection of the major lymph nodes were performed. A postoperative histopathologic examination revealed a well-differentiated tubular adenocarcinoma, which remained within the mucosal layer, and no lymph node metastasis was found. The postoperative course was uneventful, and the patient was discharged 10 days after surgery and has remained disease-free for 21 months.

In this case report, we describe the extremely rare case of a collision tumor comprising cancers of the bile duct and the pancreas. A 70-year-old man was referred to our hospital with a diagnosis of obstructive jaundice. He was diagnosed with pancreatic head cancer, and we performed a pancreaticoduodenectomy with lymph node dissection. At laparotomy, there were two palpable masses in the vicinity of the confluence of the cystic duct and the head of the pancreas. The resected specimen demonstrated tumors at the confluence of the cystic duct and in the pancreatic head. Histopathological examination demonstrated a moderately differentiated tubular adenocarcinoma in the pancreatic head and a well-differentiated tubular adenocarcinoma at the confluence of the cystic duct. Immunostaining was negative for p53 and MUC6 in the pancreatic head tumor; however, immunostaining was positive for both in the tumor located at the confluence of the cystic duct. The two tumors were histologically different and were diagnosed as collision cancer caused by the collision of the bile duct and pancreatic cancers.

Aim. To analyze the risk factors for pancreatic stent migration, dislocation, and fracture in chronic pancreatitis patients with pancreatic strictures.Materials and Methods. Endoscopic stent placements (total 386 times) were performed in 99 chronic pancreatitis patients with pancreatic duct stenosis at our institution between April 2006 and June 2014. We retrospectively examined the frequency of stent migration, dislocation, and fracture and analyzed the patient factors and stent factors. We also investigated the retrieval methods for migrated and fractured stents and their success rates.Results. The frequencies of stent migration, dislocation, and fracture were 1.5% (5/396), 0.8% (3/396), and 1.2% (4/396), respectively. No significant differences in the rates of migration, dislocation, or fracture were noted on the patient factors (etiology, cases undergoing endoscopic pancreatic sphincterotomy, location of pancreatic duct stenosis, existence of pancreatic stone, and approach from the main or minor papilla) and stent factors (duration of stent placement, numbers of stent placements, stent shape, diameter, and length). Stent retrieval was successful in all cases of migration. In cases of fractured stents, retrieval was successful in 2 of 4 cases.Conclusion. Stent migration, fracture, and dislocation are relatively rare, but possible complications. A good understanding of retrieval techniques is necessary.

Congenital inferior vena cava (IVC) anomalies are silent and detected incidentally on imaging. Double IVC is the most common IVC anomaly and is usually characterized by the presence of an IVC on each side of the abdominal aorta. In contrast, right double IVC, which is defined as two post-renal IVCs positioned to the right of the abdominal aorta, is seldom recognized. We report a rare case of a complete right double IVC with a circumcaval ureter that was incidentally detected by CT and describe the embryological and clinical implications.

To analyze the risk factors for biliary stent migration in patients with benign and malignant strictures. Endoscopic stent placement was performed in 396 patients with bile duct stenosis, at our institution, between June 2003 and March 2009. The indications for bile duct stent implantation included common bile duct stone in 190 patients, malignant lesions in 112, chronic pancreatitis in 62, autoimmune pancreatitis in 14, trauma in eight, surgical complications in six, and primary sclerosing cholangitis (PSC) in four. We retrospectively examined the frequency of stent migration, and analyzed the patient factors (disease, whether endoscopic sphincterotomy was performed, location of bile duct stenosis and diameter of the bile duct) and stent characteristics (duration of stent placement, stent type, diameter and length). Moreover, we investigated retrieval methods for migrated stents and their associated success rates. The frequency of tube stent migration in the total patient population was 3.5%. The cases in which tube stent migration occurred included those with common bile duct stones (3/190; 1.6%), malignant lesions (2/112; 1.8%), chronic pancreatitis (4/62; 6.5%), autoimmune pancreatitis (2/14; 14.3%), trauma (1/8; 12.5%), surgical complications (2/6; 33.3%), and PSC (0/4; 0%). The potential risk factors for migration included bile duct stenosis secondary to benign disease such as chronic pancreatitis and autoimmune pancreatitis (P = 0.030); stenosis of the lower bile duct (P = 0.031); bile duct diameter > 10 mm (P = 0.023); duration of stent placement > 1 mo (P = 0.007); use of straight-type stents (P < 0.001); and 10-Fr sized stents (P < 0.001). Retrieval of the migrated stents was successful in all cases. The grasping technique, using a basket or snare, was effective for pig-tailed or thin and straight stents, whereas the guidewire cannulation technique was effective for thick and straight stents. Migration of tube stents within the bile duct is rare but possible, and it is important to determine the risk factors involved in stent migration.

Hemobilia represents gastrointestinal bleeding that develops as a result of communication between blood vessels and the biliary tract, which causes the blood to reach the duodenal papilla. It is characterized by biliary colic as the initial symptom, and the complications of cholangitis, obstructive jaundice and/or anemia. In general, definitive diagnosis is made by esophagogastroduodenoscopy which confirms bleeding from the duodenal papilla. Abdominal US and abdominal enhanced CT are performed to identify the source of the bleeding, as well as ERCP for biliary drainage to control the comorbid cholangitis. If active hemorrhage accompanied by worsening of the anemia is suspected, abdominal angiography is performed to selectively image the hepatic artery. Then, embolization of the culprit vessel is recommended. In our patients with difficult hemostasis, because of the direct compression hemostasis to the tumor site achieved with the fully covered metallic stent and secondary compression hemostasis due to blood clots, the bleeding could be controlled.

Aims: Our aim was to investigate plasma amino acid levels in chronic pancreatitis (CP) patients and examine their relationship with exocrine insufficiency. Methods: Thirty-nine patients with alcoholic CP and 20 healthy controls were examined. CP patients were divided into an exocrine normal group (n = 28) and an exocrine insufficiency group (n = 11). Selected clinical and laboratory values were compared among the three groups, and the effect of an elemental diet was observed in 6 patients of the exocrine insufficiency group. Results: Total amino acid concentration was significantly higher in the control group than in the exocrine normal group and exocrine insufficiency group (p = 0.032, p = 0.020). In the exocrine insufficiency group, significant reductions in the concentrations of serum histidine and methionine were found compared with the control group and exocrine normal group (histidine: p = 0.032, p = 0.045; methionine: p = 0.043, p = 0.049). In the exocrine normal group and exocrine insufficiency group, significant elevation in the concentration of serum glutamate was found compared with the control group (p = 0.036, p = 0.029). Elemental diet improved these amino acid concentrations. Conclusion: Patients with CP exhibit alterations in the levels of several amino acids, such as histidine, methionine, and glutamate. These amino acid deficiencies seem to correlate with exocrine insufficiency and be improved by an elemental diet.

To determine the effectiveness of pancreatic duct (PD) stent placement for the prevention of pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP) in high risk patients. Authors conducted a single-blind, randomized controlled trial to evaluate the effectiveness of a pancreatic spontaneous dislodgement stent against post-ERCP pancreatitis, including rates of spontaneous dislodgement and complications. Authors defined high risk patients as having any of the following: sphincter of Oddi dysfunction, difficult cannulation, prior history of post-ERCP pancreatitis, pre-cut sphincterotomy, pancreatic ductal biopsy, pancreatic sphincterotomy, intraductal ultrasonography, or a procedure time of more than 30 min. Patients were randomized to a stent group (n = 60) or to a non-stent group (n = 60). An abdominal radiograph was obtained daily to assess spontaneous stent dislodgement. Post-ERCP pancreatitis was diagnosed according to consensus criteria. The mean age (± standard deviation) was 67.4 ± 13.8 years and the male: female ratio was 68:52. In the stent group, the mean age was 66 ± 13 years and the male: female ratio was 33:27, and in the non-stent group, the mean age was 68 ± 14 years and the male: female ratio was 35:25. There were no significant differences between groups with respect to age, gender, final diagnosis, or type of endoscopic intervention. The frequency of post-ERCP pancreatitis in PD stent and non-stent groups was 1.7% (1/60) and 13.3% (8/60), respectively. The severity of pancreatitis was mild in all cases. The frequency of post-ERCP pancreatitis in the stent group was significantly lower than in the non-stent group (P = 0.032, Fisher's exact test). The rate of hyperamylasemia were 30% (18/60) and 38.3% (23 of 60) in the stent and non-stent groups, respectively (P = 0.05, χ(2) test). The placement of a PD stent was successful in all 60 patients. The rate of spontaneous dislodgement by the third day was 96.7% (58/60), and the median (range) time to dislodgement was 2.1 (2-3) d. The rates of stent migration, hemorrhage, perforation, infection (cholangitis or cholecystitis) or other complications were 0% (0/60), 0% (0/60), 0% (0/60), 0% (0/60), 0% (0/60), respectively, in the stent group. Univariate analysis revealed no significant differences in high risk factors between the two groups. The pancreatic spontaneous dislodgement stent safely prevented post-ERCP pancreatitis in high risk patients. Pancreatic stent placement is a safe and effective technique to prevent post-ERCP pancreatitis. Therefore authors recommend pancreatic stent placement after ERCP in high risk patients.