preparation and attachment of vascular cuffs for syngeneic liver grafting

Strategies for Efficient Vascular Anastomosis in Mouse Liver Transplantation

Mouse orthotopic liver transplantation (MOLT) is an effective experimental method first reported in 19911. This experimental model, which utilizes genetically modified mice and various research reagents, has played a pivotal role in investigating warm and cold ischemia and reperfusion injuries. However, the model&#39;s high technical complexity has hindered the development of basic medicine for liver transplantation2. MOLT involves three major steps: (1) retrieval of the liver from the donor mouse, (2) back table surgery, and (3) implantation of the liver into the recipient. Among these recipient procedures, vascular anastomosis poses the greatest challenge. While the suprahepatic inferior vena cava anastomosis is typically completed by hand stitching2, the infrahepatic inferior vena cava (IHIVC) and portal vein (PV) can be reconstructed more efficiently using plastic cuffs in place of hand-sewn sutures.
The anhepatic period signifies the interval between the removal of the recipient&#39;s native liver and the graft implantation. To ensure consistent results, it is imperative to limit the anhepatic time to less than 20 min. Consequently, studies employing this model have been confined to specific institutions3,4,5,6,7,8,9. Among the various stages of MOLT, achieving smooth PV and IHIVC reconstruction is crucial for minimizing anhepatic time and ensuring successful transplantation.
PV and IVC reconstruction is generally carried out using vascular cuffs since the cuff technique simplifies vascular anastomosis compared to hand-sewn sutures2,5,8. The technique involved in vascular cuff preparation and secure attachment of the cuff significantly impacts the complexity of recipient vascular reconstruction. Our objective is to provide detailed visual guidance for numerous technical tips related to the cuff method, thereby reducing the learning curve. These video clips will provide a clear understanding of how to attach the cuff to the vessels and reconstruct the PV and IHIVC during recipient surgery.

Author Spotlight: Exploring Cold Ischemia and Warm Reperfusion Injury in Fatty Liver Transplantation

Vascular Reconstruction with the Cuff Technique in Mouse Orthotopic Liver Transplantation

We focus our research on liver transplantation, in particular on cold ischemia and warm reperfusion injury. We use mouse liver transplantation model as a research tool for this purpose. Because the technique is difficult, so it can take a long time to learn and to achieve consistent results.In the future, we'd like to conduct research on fatty liver transplantation. This is still a problem to overcome on clinical liver transplantation.

Preparation and Attachment of Vascular Cuffs for Syngeneic Liver Grafting

To begin, prepare 16-gauge and 20-gauge intravenous catheters for the portal vein, or PV, and the infra hepatic inferior vena cava, or IHIVC, respectively. Using a scalpel, cut the catheter to create the cuff. Then with the back of the scalpel, create a shallow groove on the cuff's surface for thread fixation.Place small ice cubes in a rectangular-shaped plastic container, and position a small metal cup on top of the container. Fill the cup with organ preservation fluid and place the syngeneic liver graft in it. Under eight to 10 X magnification, gently roll the liver graft using a cotton swab, ensuring that the porta hepatis faces upwards.Thread the PV through the cuff, using a thread attached to the splenic vein. With the cuff handle at the 12:00 position, secure the handle and cuff with a bulldog clamp, positioning it two to three millimeters from the PV edge. Further secure the bulldog clamp using large vascular forceps and a fixation mold to establish the operative field.Next, increase the magnification to 15 to 20 X and carefully inspect the PV lumen. After grasping the PV lumen, externalize the thin wall of PV through the inner lumen of the cuff. Secure the fully externalized PV lumen with a double ligation using 8-O silk thread along the cuff's groove, and then cut the string.Similarly, attach the cuff to the IHIVC lumen, and fix it using 8-O silk thread. Then, to create a slipknot, pass the thread around the base of the IHIVC to temporarily ligate it.

preparation-attachment-vascular-cuffs-for-syngeneic-liver

Research

JoVE Journal

Medicine

Mouse orthotopic liver transplantation is an effective methodology for investigating the underlying mechanisms of liver ischemia and reperfusion injury. However, the technical challenges pose a barrier to utilizing this valuable experimental model and passing on these skills to the next generation. The most challenging aspect of this procedure is vascular reconstruction, including the portal vein (PV), infrahepatic inferior vena cava (IHIVC), and suprahepatic inferior vena cava. The use of plastic cuffs, rather than sutures, allows for smoother PV and IHIVC reconstruction. Vessels are reconstructed by attaching a cuff made from an intravenous catheter to the tip of the graft vessel and interposing the cuff into the recipient vessel. The two most crucial aspects are properly visualizing the inner lumen of the vessel and avoiding the use of excessive force. Our aim is to provide a technical overview of vascular reconstructions using the cuff technique in recipient surgery. These technical tips for the cuff technique are expected to help microsurgeons facilitate vascular reconstruction and advance their research.

This protocol provides technical information for vessel reconstruction using the cuff technique in mouse orthotopic liver transplantation.

Mouse orthotopic liver transplantation is an effective methodology for investigating the underlying mechanisms of liver ischemia and reperfusion injury. ...

Portal Vein and Infrahepatic Inferior Vena Cava Reconstruction in Mouse Liver Transplantation

After extracting the native liver from the anesthetized recipient mouse, gently grasp the recipient's liver portal vein or PV edge using pen forceps and secure it with a vice. Pass an eight oh silk thread around the PV and place a vascular clamp on it. Create a one fourth circumferential section approximately 0.5 millimeters from the PV edge.While passing saline through the hole, use a specialized instrument to enlarge the hole. Grip the cuff handle using straight forceps and insert it into the lumen. Then secure the cuff with an 8.0 silk thread.Remove the vascular clamp from PV to allow reperfusion of the liver. Finally, carefully release the pen forceps to complete the PV reconstruction. After positioning the liver lobe, Move the pen forceps attached to the recipient IHIVC dorsal to the graft's right lower lobe.Then secure the IHIVC with a vice. Rub away any remaining liver tissue around the recipient's IHIVC with a cotton swab. Pass an 8.0 silk thread around the recipient's IHIVC.Create a one fourth circumferential section, approximately 0.5 millimeters from the recipient's IHIVC edge. After flushing the lumen with saline, insert the cuff into the IHIVC lumen. Carefully secure the cuff with an 8.0 silk thread.Finally, remove the vascular clamp and pen forceps. The preservation of the graft at cold temperatures for one hour resulted in serum alanine aminotransferase levels, averaging approximately 2000 units per liter at six hours post reperfusion. A survival rate of 100%was observed at seven days following transplantation.