[Design of an improved percutaneous transhepatic cholangio drainage tube based on MRCP imaging data]

Objective: Quantified MRCP imaging data was used as a reference for design and preparation of a modified percutaneous transhepatic cholangio drainage (PTCD) tube. Methods: 3.0 T upper abdominal MR and MRCP imaging data of 2 300 patients treated from July 2015 to July 2020 at the Department of Radiology of the Affiliated Cancer Hospital of Zhengzhou University were screened and a total of 381 patients diagnosed with biliary duct structures were identified. Causative etiologies among these patients included pancreatic adenocarcinoma (pancreatic head), cholangiocarcinoma, ampullary carcinoma, as well as intrahepatic and/or extrahepatic bile duct dilation. An improved PTCD tube was designed based on MRCP quantification of left and right hepatic and common hepatic duct length. Results: In the setting of biliary obstruction caused by malignancy, the distance of the left hepatic duct from its origin to the point of left and right hepatic duct confluence was 15.9±3.8 mm, while the distance of the right hepatic duct from its origin to the point of left and right hepatic duct confluence was 12.4±3.2 mm; the length of the bile duct from its origin to the point of left and right hepatic duct confluence was 34.0±8.1 mm. The improved PTCD tube design incorporated an altered length of the drainage orifice. Conclusion: MRCP imaging of the biliary tract is effective for measuring biliary tract length in the setting of pathological dilation. Based on our biliary tract measurements, a modified PTCD tube was designed to more effectively meet drainage requirements and manage biliary obstruction caused by Bismuth-Corlette type Ⅱ and Ⅲ malignancies.