The primary endpoint of this study was the rate of recurrent biliary obstruction (RBO) until undergoing surgery or being diagnosed as unresectable. The secondary endpoints were time to RBO, factors related to RBO, complications related to endoscopic retrograde cholangiography (ERC), and postoperative complications.
Cases were collected at a single center and reviewed retrospectively. This study was approved by the Institutional Review Board of Nagoya University Hospital (No. 2016-0032) and was performed according to the guidelines set forth in the Helsinki Declaration for biomedical research involving human subjects (clinical trial registration number: UMIN000025631).
This study included patients diagnosed with suspected resectable PHCC based on multidetector row computed tomography and treated with the IS or FCSEMS as final scheduled preoperative biliary drainage (FSPBD) between May 2017 and August 2019 at Nagoya University Hospital. The following exclusion criteria were applied: (i) difficulty in using the endoscopic approach to the duodenal papilla; (ii) Eastern Cooperative Oncology Group performance status 2-4; (iii) percutaneous transhepatic biliary drainage before FSPBD; (iv) FSPBD accompanied by endoscopic nasobiliary drainage; and (v) FSPBD using both IS and FCSEMS.
The most appropriate surgical procedure was planned based on multidetector row computed tomography, evaluated the patient's condition (presence of obstructive jaundice or cholangitis), and then performed ERC. The endoscope used was a JF260V™ or TJF260V™ (Olympus Medical Systems Corporation, Tokyo, Japan); VisiGlide2™ (Olympus Medical Systems Corporation, Tokyo, Japan), EndoSelector™ (Boston Scientific Japan, Tokyo, Japan), or M Through™ (Medicos Hirata, Osaka, Japan) was used as the guidewire. During ERC, malignancy and longitudinal tumor progression were assessed by intraductal ultrasonography19 and biliary forceps biopsy20,21 and drainage of the future remnant liver lobe(s) was performed. Endoscopic nasobiliary drainage was selected when the total bilirubin level was more than 3 mg/dl22, and IS or FCSEMS was used instead when the total bilirubin level was less than 3 mg/dl if the waiting period before surgery was expected to exceed two weeks.
Stents were placed in the left bile duct in cases of planned right hepatectomy, in the right bile duct in cases of left hepatectomy, in the left lateral sectional bile duct in cases of right hepatic trisectionectomy, and in the right posterior sectional bile duct in cases of left hepatic trisectionectomy.
IS and FCSEMS are indicated for patients in whom cholangiography shows that the lower end of the stenosis is more than 20 mm from the papilla. When the confluence of the first bile duct on the future remnant liver lobe(s) is more than 5 mm from the upper end of the stenosis, FCSEMS is indicated, and when it is less than 5 mm, IS is indicated.
In this study, FCSEMS (Niti-S™, 6 mm x 40 mm; Century Medical Inc, Tokyo, Japan or Hanaro™, 6 mm x 60 mm; Boston Scientific Japan, Tokyo, Japan) was used depending on the stenosis length. The FCSEMS was placed above the papilla in such a way that the upper end of the stent would not obstruct the bile duct branch of the future remnant liver lobe(s) and the lower end of the stent would be more than 20 mm above the papilla. The IS was placed with its upper end in the bile duct of the future remnant liver lobe(s) and the lower end more than 20 mm above the papilla. An IS with a preloaded thread, Amsterdam type (Through＆Pass™ 7 Fr 9 cm deep or light angle; Gadelius Medical K. K, Tokyo, Japan), was used. Deep-angle stents were used when the bending from the hilar bile duct to the inserted bile duct was strong and light-angle stents when the bending was weak (Figure 1).
When RBO occurred after stenting, endoscopic treatment was performed immediately. The IS or FCSEMS was grasped with forceps and removed, and endoscopic nasobiliary drainage was placed in the same bile duct branch and/or in the undrained bile duct branch of the future excisional liver lobe(s).
Adverse events after ERC, such as cholangitis, cholecystitis, and pancreatitis, were assessed based on Tokyo criteria 201423.
RBO is defined as redilatation of intrahepatic bile ducts with elevated hepatobiliary enzyme levels and includes segmental cholangitis in undrained areas (bile duct branch of future excisional liver lobe). Patients who did not develop RBO until surgery or those who were diagnosed as unresectable were considered censored cases. Time to RBO was defined as the time between FSPBD and RBO.
Factors affecting RBO in both groups were evaluated. Stenosis length was defined as the distance from the lower end to the upper end of the stenosis in the bile duct branch of the future remnant liver lobe(s). Obstruction of bile duct branches by stenting was defined as stent occlusion of the bile duct branch of the future excisional liver lobe(s) that could be opacified at ERC. The distance from the stenosis to the branch was defined as the distance between the upper end of the stenosis and the confluence of the first branch of the future remnant liver lobe(s).
Bile leakage, liver failure and pancreatic fistula were examined according to the International Study Group of Liver Surgery and International Study Group of Pancreatic Surgery. Grades B and C, which require active therapeutic intervention, were assessed as postoperative complications24-26. Bile leakage and liver failure were classified as with or without hepatectomy and pancreatic fistula as with or without pancreatectomy.
Statistical calculations were performed using SPSS 27.0 (SPSS, Chicago, Illinois, USA). The analyses were performed using the Mann-Whitney U test for continuous variables and the chi-squared test for categorical variables. Continuous parameters are presented as medians (ranges). Time to RBO was calculated using the Kaplan–Meier method and the log-rank test.
For patients in each group who required reintervention due to RBO after FSPBD, risk factors for RBO were calculated by univariate analysis and then examined by Cox proportional hazard analysis; multivariate analyses included factors with P<0.2 in univariate analysis. The analysis also checked for noncollinearity among these factors.