Reply: Blocked drain switch-hepatic venous outflow obstruction

To the editor, We thank Dr. Guo and colleagues for their interest in our manuscript published in Liver Transplantation regarding hepatic venous outflow obstruction after adult living donor liver transplantation.1 They discussed 2 different choices of venous access (femoral and internal jugular) and highlighted the differences in procedure-related risks and successful rates of these 2 accesses. They suggested that we should provide more information about the selection of interventional radiology access to guide clinical practice. We agree with the opinion that femoral vein access is theoretically safer than internal jugular vein access. However, catheter canulation to the hepatic vein is sometimes difficult in femoral vein access due to the acute angle between the hepatic vein and the IVC (especially for right liver grafts), as Dr. Guo mentioned. This also stands true for stent insertion, and there is a risk of unstable stent positioning or stent migration. Currently, we have no uniform criteria for the choice of venous access, and it is decided on a case-by-case basis. We preferred the use of femoral access during the early era (2000–2010), but we have experienced several cases in which stent insertion was difficult. Recently, internal jugular vein access is more often selected because it is technically easier. In fact, most (4/5) of the stent placement in our cohort was performed by internal jugular access. In addition, when repeated interventional radiological procedures are needed, it is important to select suitable venous access based on the angiographic findings of the initial session. In fact, in many patients in our study, the first angiogram and balloon angioplasty were performed with femoral access, but the second procedure (either repeat balloon angioplasty or stent placement) was performed by internal jugular access. There is no need to adhere to one approach. Regarding success rates, we believe there is no difference between the two approaches if an experienced interventional radiologist selects the appropriate venous access and carefully carries out the procedure. Regarding the risks associated with internal jugular vein access, we believe it is safe if the venous puncture is performed under both ultrasound and fluoroscopic guidance. Among the 15 patients in our study, we did not experience any serious complications related to venous puncture. As mentioned by Dr. Guo, the working space tends to be smaller in jugular vein access; however, there is still enough space for 2 interventional radiologists to safely and efficiently perform the procedures. In conclusion, based on our experience, both accesses are feasible and have similar success rates. It is paramount to select the access that is favorable from the venous anatomy standpoint and the type of procedure according to each individual patient.