New Thrombectomy Technique for Total Portal Vein Thrombosis in Liver Transplantation

I am Dr. Wellington Andraus, and I'm from University of Sao Paulo in Brazil. As you know, portal vein thrombosis is a real challenge in liver transplantation, increasing the bleeding, morbidity, and mortality to the procedure. Here we describe a new technique that facilitates the removal of the portal vein thrombosis. We do a circle incision near the liver without cutting the thrombosis. And the advantage of this procedure is that it's easier to remove the entire thrombus without fracturing. So this is a new tool for portal vein thrombosis in liver transplantation that many times is a real challenge for the procedure. Thank you. This is a CT scan of a cirrhotic patient in the wait list for liver transplantation. We can observe a complete thrombosis of the main portal vein as well as of its left and right branches. It is classified, therefore, as a grade two portal vein thrombosis in the Yerdel classification. This is a CT scan of a cirrhotic patient with acute and chronic liver failure. We can observe an extensive chronic thrombosis in the main portal vein that's partially recanalized and also extends to the intra-hepatic branches. After the hepatic artery and common bile duct have been ligated, we dissect the portal vein as caudally as possible in order to reach a segment of the vein without thrombus. Once isolated the portal vein, we use a vessel loop as a tourniquet to avoid damage to the vein. In the more cranial portion of the vein, we applied a vascular clamp in this case. We then incised the portal vein near the clamp in a circular fashion without cutting the thrombus. We start to evert the wall of the vein, separating it from the thrombus. As you can see in this case, we do gentle movements to separate the wall of the vein from the thrombus. The thrombus remains stable during this technique and we use a combination of forceps, periosteal dissector, and also we sometimes cut the portion of the thrombus that are more firmly attached to the wall of the vein. So now we continually progress towards the vessel loop, carefully separating the wall of the vein from the thrombus. Compared to the traditional technique, we feel that it's easier to perform a total thrombectomy using this approach because the thrombus is not fractured during the thrombectomy. So now we can see that we have almost reached the portion of the vein without thrombus. And once the thrombus has been removed from the vein, it remains attached to the explanted liver. Thrombus has been completely removed and we are checking the integrity of the portal vein in order to later perform the end-to-end portal vein anastomosis to revascularize the liver graft. In this second case, we have ligated with silk the right and left portal veins of the native liver because they also contain the thrombus. Another difference in this case is that we have performed a very extensive caudal dissection of the portal vein, reaching the hepato-pancreatic portion. In order to perform a full vascular control of the area in which we are going to perform the thrombectomy, we also had in this case to isolate and apply a tourniquet in a branch of the hepato-pancreatic portion of the portal vein. And here we can see the final aspect using this approach, where the thrombus remains uncut and the wall of the portal vein has been completely averted until the region with the vessel loop. In this first case, we can see that we have obtained a very good portal flow after the thrombectomy. We can remove now the vessel loop and replace it with a portal clamp in order to continue the total hepatectomy. We can also see that the thrombus remains attached to the native liver. And here we can see the liver graft after vascularization, showing signs of good perfusion. This is a postoperative CT scan performed eight days after the transplantation. We can see that the portal vein is patent and with a good flow. The liver graft has a good aspect as well. In the second case, this is the final moment of the thrombectomy, and you can see after the thrombus has been removed, we have obtained a very good portal flow. This is a picture of the explanted liver in the second case. We can see that the thrombus remains attached to it, including its portion in the right and left portal veins. This is a picture of the liver graft after vascularization, showing good signs of perfusion. In this CT scan performed six days after the transplantation, we can observe that the portal flow of the liver graft is preserved. As demonstrated in these cases, performing thrombectomy in chronic thrombosis is feasible with this new approach. Fixating the thrombosis with a clamp or a suture to the portal vein or portal branches guarantees the stability of the structures for a better and safer separation of the portal vein from the thrombus, ensuring total thrombectomy with no thrombus left in the wall or looming off the vein. Optimal portal flow can then be obtained, leading to physiological and anatomical restoration of the portal system. In comparison to the traditional technique, this new approach presents less risk of vascular injuries and of incomplete thrombectomy, as the thrombus is removed without fragmentation. It does seem to be a reliable option for cases with chronic Yerdel grade two portal vein thrombosis. As we have performed this technique in only two cases, further experience is needed to verify total results. For that reason, we encourage more transplant surgeons to replicate this approach in similar cases.