Technique of Porcine Liver Procurement and Orthotopic Transplantation using an Active Porto-Caval Shunt

The overall goal of this procedure is to reliably perform an allogeneic liver transplantation in pigs, ensuring stable animal hemodynamics per and postoperatively. This is accomplished by first implementing an active portal caval jugular shunt before cross clamping the vena CVA and portal vein in order to avoid intestinal congestion during the implantation phase. Next, an orthotopic liver transplantation by cava replacement technique is performed, starting with the supra hepatic cable anastomosis.

Then the portal vein is anastomosis and the liver is reperfused. Finally, the portal caval jugular shunt is removed and the remaining anastomosis of the infra hepatic vena cva, the hepatic artery and the common bile duct are completed. Ultimately, the pig has weaned off the anesthesia and monitored closely postoperatively.

The main advantage of this technique over existing methods like total vascular occlusion or passive inance, is that in this particular technique, splenic congestion during the anabolic phase is completely avoided. In this manner, we prevent venous hypertension and capillary damage that can lead to major intestinal ischemia and hemodynamic instability At after excising the liver from a donor pig and anesthetizing the recipient pig according to the text protocol, placed a recipient pig in a supine position on a surgical table on top of a heating pad. Following intubation, use cap geometry to confirm it has been performed correctly with pulse oximetry on the tail or ear of the pig.

Monitor the heart rate and oxygen saturation. Perform the Seldinger technique to insert a sheath inducer into the left external jugular vein that will be used later for an active portal cable jugular bypass. After inserting a total parenteral nutrition catheter into the right external jugular vein under sterile conditions, dissect the right carotid artery and insert a polypropylene catheter for invasive arterial pressure monitoring.

Then use two zero silk tie to surround the artery to allow emergency ligation. Next, make a midline laparotomy and insert an abdominal retractor to get sufficient access to the right upper quadrant. Then in middle steps, divide the hepato duodenal ligament close to the liver between ties.

Identify, divide and mark the branches of the hepatic artery and bile duct. Next, dissect the hepatic artery in the retrograde direction until reaching the division of the gastroduodenal artery. Then free the portal vein from adherent tissue using an electrocautery mobilized vena CVA from the retroperitoneum on the right side to expose the helium of the spleen approximately half along the spleen's length.

Carefully clear off the splenic artery and vein from adherent peritoneal layers. Then use 4 2 0 silk ties to surround both the splenic artery and vein. Insert an 8.5 French sheath inducer with two additional holes in the catheter's tip into the splenic vein pointing distally towards the portal vein with one of the two zero ties.

Fix the catheter distally to its insertion and use another two zero tie to close the vein proximal to the insertion. Next, fill saline into a bypass consisting of a centrifugal pump head, a jugular tube, and an inflow from both a portal branch and a caval branch. Put a tubing clamp onto the proximal end of the caval tubing.

Then connect the portal and the jugular opening of the bypass to both sheath introducer catheters and use a metal hose clamp ring to seal the connection. Place the centrifugal pump head into its pump position three minutes after administering 1000 milligrams of texa acid and 10, 000 IU of heparin intravenously. Open the clamps of both sheath introducer catheters and cross clamp the portal vein.

Next, start the centrifugal pump at about 1, 500 rounds per minute. Then using a deba back clamp cross clamp, the infra hepatic vena CVA just cranial to the renal veins. Apply firm pressure onto the liver tissue to squeeze out a portion of the remnant blood.

Then using a statsky clamp cross clamp the sup hepatic vena cava, including a diaphragmatic rim while retracting the liver coddly. Now cut the supra hepatic vena CVA directly at its border to the liver tissue, and cut the portal vein near the hepatic helium approximately four centimeters cranial to the infra hepatic CVA clamp. Cut a hole into the anterior wall of the vena cava into this hole.

Position the connector of the bypass cable opening with a lure lock facing anteriorly with one zero silk ties. Secure the connector in the infra hepatic cva. Then open the tubing clamp of the cable branch of the bypass.

Finally open the infra hepatic CVA clamp to allow a cable jugular bypass in addition to the existing portal jugular bypass. After increasing the pump's speed to about 2, 500 rounds per minute, confirm that the bypass outflow on the jugular side is between 900 to a thousand milliliters per minute. Using four zero monofilament polypropylene sutures.

Close all three phrenic vein oste osteos on the recipient side at the sup hepatic CVAs aperture stitch. Double armed four zero monofilament polypropylene sutures inside, outside in both corners of the SUP hepatic CVA on the recipient side. After placing the donor organ in the abdominal cavity, trim the donor S hepatic vena CVA to fit the recipient side.

Using the inside needles of the recipient side corner stitches, make it inside outside corner stitch on each of the sides of the super hepatic donor cva. Once the recipient and donor Austria are approximated, tie both endings of the left suture. Then make an outside inside stitch of the recipient kava back wall next to the tie and run over the back wall.

Ideally averting the kava wall with the remaining suture run over the front wall from the left corner. Then tie together both sutures used for the back and front walls. After trimming the donor portal vein to an appropriate length, use six zero monofilament polypropylene sutures to perform an end-to-end portal Vein anastomosis as just demonstrated shortly before completing the front wall, use another flush line to intubate the lumen of the infra hepatic hava and with one liter of room temperature saline.

Flush out the UW solution via the infra hepatic hava portal vein. Next, complete the anastomosis and tie the sutures leaving approximately 0.5 centimeters of growth factor. Then place another deba back clamp onto the donor infra hepatic cva.

Open the S hepatic CVA clamp and check for bleeding. Then open the portal clamp to reperfuse the liver, reclamp the recipient side of the infra hepatic vena cava and put a tubing clamp on the cable part of the bypass. After stopping the centrifugal pump, cut the ties of the cable connector and remove it.

Return the remaining blood from the bypass to the pig through the jugular catheter. Now close the clamp, the jugular catheter, and disconnect the bypass. Then after administering 100 milligrams of protamine sulfate to antagonize a heparin, use five zero monofilament sutures to perform an end-to-end anastomosis of the infra hepatic cva.

Again, reperfused infra hepatic lower CVA by releasing both clamps. After trimming an aortic patch around the donor's celiac trunk, put a bulldog clamp onto the common hepatic artery proximally to the junction of the gastroduodenal artery. Once the hepatic artery has been flushed with heparin, use six zero monofilament polypropylene sutures to anesti os.

The arterial osteo end to end in a running parachute technique, then reperfuse by first opening the distal and then the proximal bulldog clamps with 2 6 0 monofilament sutures. Use the running technique to anesti mos the bile duct end to end. After checking for hemostasis, remove the sheath introducer catheter from the splenic vein.

Use the two remaining ties to close the proximal and distal ends with the size one monofilament absorbable suture. Close the abdominal wall. Finally, use either a skin stapler or running two zero suture to close the skin.

Refer to the text protocol for postoperative care. In our first transplantation study, 100%of the recipient pigs receiving livers from a heart beating donor or HBD survived until the end of follow-up five days after transplantation. However, only 50%of pigs receiving livers from donors after circulatory death or DCD made it to the five day follow up analysis of blood samples from hepatocellular injury.

Biliary and liver function showed that a ST levels reached a peak after 24 hours in both groups. That was much higher in the DCD group compared to the HCD group and return to almost normal values after five days. Similarly, as shown in this graph, alkaline phosphatase values were markedly increased after 36 hours in the DCD group when compared to the HBD group as demonstrated here.

While total bilirubin was stable in the HPD group, it gradually increased in the DCD group until day five and shows a high standard deviation suggesting biliary injury in only a portion of the experimental group. In this figure INR as a marker of liver function showed a trend similar to the A ST values that peaked at 24 hours and were restored to almost normal values. After five days After watching this video, you should have a good understanding of how to use an active venous venous bypass during orthotopic pig liver transplantation.

This way, we ensure stable and mo conditions during the entire procedure.