Heterotopic Auxiliary Rat Liver Transplantation With Flow-regulated Portal Vein Arterialization in Acute Hepatic Failure

Acute hepatic failure poses a severe problem in clinical medicine leading to a mortality rate of 60 to 80%in acute hepatic failure. Auxiliary liver transplantation is a promising alternative therapy. After regeneration of the native liver, the immunosuppression can be discontinued and the liver graft can be explanted or left to atrophy.

However, the operative technique for auxiliary liver transplantation is controversial. The APOL method that is the orthotopic implantation of auxiliary segments averts most of the technical problems that could arise. However, this method necessitates extensive resections of both the native liver and the graft.

In 1998, Erhart and his team initiated the heterotopic auxiliary liver transplantation called halt By utilizing portal vein arterial called PVA, this technique showed promising initial clinical results. We have developed a halt technique with flow regulated portal vein arterial in the rat for research purposes. This video illustrates in detail this new Experimental technique 224 Syngen male Louis frats weighing 250 to 350 grams were operated.

Donor and recipient operations were performed under inhalation anesthesia. General anesthesia of the animals was induced with oph fluorine in a plexiglass box connected to the anesthesia machine at an oxygen flow meter rate of one liter per minute. The vaporizer had a concentration of 5%ease of fluorine.

The anesthesia was maintained at 1.5%Local ethics committee approval was obtained for all experiments, which were performed in accordance with the animal protection phia guidelines. During the following operation. The portal vein is arterialized via the right renal artery.

The blood flow in the Arterialized portal vein is regulated by a stench having an inner diameter of 0.3 millimeters and a length of eight millimeters. Pilot experiments had shown that a stent diameter of 0.3 millimeter yields an average blood flow in the Arterialized portal vein. That is within the upper physiological range.

The hepatic microcirculation is visualized by OPS imaging, a reflection spectroscopy technique that allows real-time observation of the hepatic microcirculation in vivo. Without the use of contrast agents under physiological saline immersion, the probe is gently positioned on the surface of the right liver lobe. It is important here not to compress the liver Parenchyma.

The donor operation is demonstrated First after median laparotomy. The left lateral lobe and the median lobe of the graft are resected as described by Higgins. Here you see the preparation of the Hepato duodenal ligament.

The bile Duct is ligated first in order to induce congestion and dilation of the small bile duct. The gastroduodenal vein in artery are ligated And transected. Then the CIC trunk, the common hepatic artery, the left gastric artery and the splenic artery are isolated Afterwards.

The left gastric artery and the splenic artery are transected. Here you see the CIC trunk and here The common hepatic artery. The congested bile duct is incised and a 20 gauge Stent is introduced into it.

The positioning of the stent must Ensure the drainage of the entire hiller bile duct system. The bile Duct is transected distally to the stent. The infra hepatic segment of the cable vein is isolated right above the right renal vein.

Here You see the tus after preparation, after ligation Of the aorta above the celiac trunk. The portal vein is clamped and incised. The perfusion catheter is now introduced and the perfusion is performed with 30 milliliters of histidine tryptophan gito glu solution.

The diaphragm and the sup hepatic cable vein are a cut to allow the purate to flow out. The CIC trunk along with an aortic patch is excised and rinsed with histidine tryptophan ketoglutarate solution. The infra hepatic cable vein is transected right above The right renal vein.

Then a stent with a diameter of 0.3 millimeters is placed in the portal vein and fixed with the ligature. The portal vein is transacted distally to the Scent. Here you see the bile duct, the portal vein, the celiac trunk, and the infra hepatic Caval vein.

After ligation of the supra hepatic caval vein, it is transected along with a cuff of diaphragm. The graft is explanted and stored in histidine tryptophan ketoglutarate solution at four degrees Celsius In a plastic bag on ice Corner, sutures are placed in the infra hepatic caval vein. The recipient operation Is demonstrated next.

After laparotomy and preparation, the infra hepatic caval vein, the right renal artery is first isolated. Then the ureter is ligated and transected. After the right renal artery has been clamped at its origin, the right renal Vein is ligated.

Then after transection of both Renal vessels, the nephrectomy is performed. Subsequently, the right renal Artery is shortened and rinse with heparin saline solution After proximal And distal clamping of the infra hepatic cable vein. The right renal vein is transected proximally to the ligature.

In this manner, an oval lumen is created in the infra hepatic cable vein. The graft is placed below the native liver. The donor's infra hepatic cable vein is anastomose end to side to the recipient's cable vein with an eight oh ethylene Running suture.

After Rinsing with heparin saline solution, the stent in the portal vein is introduced into the right renal artery. The portal vein and renal artery are connected with two stitches. Using a stent with an inner diameter of 0.3 millimeters and a length of eight millimeters allows an arterial venous anastomosis with standardized flow regulated Inflow rates.

The linking stent is fixed in the renal artery with a ligature To allow reperfusion. The arterial clamp is first removed, followed by both venous Clamps. Now You see the microcirculation at the moment of reperfusion starting from the interlobular vessels, continuing along the sinusoids and arriving to the central vein of the hepatic lobule.

Here you now see the reperfused graft, the arterialized portal vein, and the bile duct. The infrarenal aorta is prepared and then clamped and incised. An end To side anastomosis between the aorta and the celiac trunk using an aortic patch is performed with a 10 O ethylene running Suture.

After a purse string Suture has been applied, a small incision is made in the duodenal wall. The stented bile duct is then introduced in the duo denim and the purse string suture Is tightened. Finally, the duodenum and the bile duct are held tightly together with two stitches.

Here you See the reperfused graft and the native liver that had been sub totally resected to mimic acute liver failure. The animals were postoperatively injected with buprenorphine subcutaneously every eight to 12 hours. For two days.

The peri-operative survival rate was 90%and the six week survival rate was 80%During the first postoperative week, four rats died from peritonitis due to a dislocation of the stent and biliary leakage. Moreover, seven rats died from pneumonia, intraabdominal abscess, or ileus. The surviving animals were in excellent general condition.

Six weeks after operation, the parameters of liver synthesis were within the normal range. Here you see the scientists six weeks after heterotopic auxiliary rat liver transplantation with portal vein arterial. Six weeks after operation, the native liver regenerated showing an increase in weight from 2.3 plus or minus 0.8 grams to 9.8 plus or minus one gram.

At this time, the GRAT was atrophic and the liver weight decreased from 3.3 plus or minus 0.8 grams to 2.3 plus or minus 0.8 grams. The total weight of both livers was within the physiological ratio of liver weight to body weight in the histopathological stain with hematin eoin at six weeks after halt. Regular hepatocytes were observed with neither edema nor fatty degeneration.

All graphs showed slight proliferation of bile, ductile and cholangitis due to sludge formation. Only in two graphs could low grade interper CTUs hepatocellular necrosis be observed. The use of a stent having an inner diameter of 0.3 millimeters and a length of eight millimeters yields an average portal blood flow after reperfusion of the arterialized portal vein, that is within the upper physiological range.

The biliary drainage is the achilles heel of liver transplantation. In rat liver transplantation, the recipients often die within the first postoperative days due to biliary leakage and peritonitis. We perform the colo doho od ostomy using a stent, a per string suture, and two additional stitches which secure it against leakage and disconnection.

With this technique, the biliary complications were reduced to 4%In this current study, a subtotal resection of native liver was performed. We use this method first described by amond to induce acute liver failure. In contrast to the application of hepatotoxic agents, this method is standardized and shows no side effects on other organ systems or on the graft.

Unlike orthotopic liver transplantation, there's no end hepatic phase. During the heterotopic liver transplantation, the Anas can be performed without any time pressure. Moreover, in the heterotopic position, there is no interference by the moving diaphragm.

Furthermore, the recipient's portal vein is not clamped, thereby avoiding venous congestion of the small intestine, spleen, pancreas, and stomach. With this technique, we were able to obtain promising long-term results in terms of graft, morphology and function, heterotopic auxiliary rat liver transplantation with flow regulated portal. Vein arterial is an innovative technique that offers few pitfalls and is easy to learn.

This technique is suitable to investigate the effect of portal vein, arterial hepatic hyperperfusion, and blood flow regulation upon liver microcirculation function and morphology. This model enables future Studies on liver regeneration in inter liver competition.