After entering the abdomen through the right subcostal bilateral incision, vertically extended to the xifoides, the fixation elements for the liver are placed for its later removal, then the dissection of the vascular pedicles takes place: the supra and infra hepatic vena cava and the portal vein and the hepatic artery ligation and the bile duct. This stage of the surgery is characterized by bleeding, depending on adhesions, portal hypertension and coagulopathy.
To begin the clamping of the portal vein and the supra and infra hepatic vena cava is performed, and then the liver is removed. The implant of the new liver, that is orthopedically placed, consists in the anastomosis of the supra hepatic, infra hepatic and portal vein of the donor and recipient. Due to the clamping, in this phase some hemodynamic changes are produced, these changes in the past required the use of a veno-venous bypass.
With the vascular unclamping and the hepatic reperfusion the last stage of the procedure begins. In this stage the anastomosis of the hepatic artery and the bile duct is performed: bile duct-bile duct (with or without Kehr tube) or hepatic-jejunum. Once again the hemodynamic changes (hypotension, arrhythmia, etc.) and the acidosis, known as reperfusion syndrome and the coagulopathy (fibrinolysis) govern this stage of the procedure. The progressive hemodynamic stability depends on the well-functioning of the graft; and the coagulopathy and the portal hypertension depends on the internal means of the patient. At the same time a careful haemostasis of the vascular sutures and the bleeding bed takes place, before the closing of the abdomen.
Bench surgery: At the same time of the patient’s surgery this procedure is performed, where the hepatic graft is prepared before it is placed in the recipient. It’s liberated of the lymphatic ganglion structures and of fats that surround it, preparing the vascular pedicles for the anastomosis and correcting at the same time the artery variants if there were any. In the same way the hepatic reduction and/or the liver bipartition are performed.
The preservation of the vena cava of the recipient or “Piggy-back” makes the clamping of said vein unnecessary and assures the venous return to the atrium providing more hemodynamic stability, better renal perfusion and avoiding the use of the veno-venous bypass. To add to the splanchnic venous return it’s recommended to make a temporal portal-cava anastomosis. On the other hand, the conservation of the vena cava is essential when reduced-liver grafts are being used.
It is almost a norm in paediatric transplants. It consists in using hepatic segments to adapt them to the minor capacity of the abdomen of the recipient.
It is a direct consequence of the use of reduced livers and consists in the implant of the two segments obtained from one donor into two recipients. This procedure can take place both during the bench surgery (ex-situ) or during the ablation (in-situ).
It is a technique that allows the use of hepatic segments obtained from members of the family of the recipient that voluntarily offered be a donor. While at the beginning the use of the left lateral segment was widely used to solve the shortage of donors in pediatric patients, the technique has spread to adult recipients who receive an implant whether on the right or the left lobe.
It is the use of the native liver of a recipient who carries familial amyloidotic polyneuropathy who is being transplanted, as a donor graft to another recipient. Generally this is a patient with hepatocarcinoma or of advanced age.
Is a variation that consists in the implant of a reduced graft keeping part of the whole native liver, which suffers from potentially reversible hepatic failure (hepatitis due to virus A, autoimmune, etc.), with the intention of withdrawing the immunosuppression once it is recovered.
There are frequently used in cases of extensive thrombosis and/or poor quality of the recipient’s vessels.
The liver transplant is indicated for acute or chronic liver failure. The failure is evident in clinical signs such as jaundice, encephalopathy, ascites, and bacterial peritonitis; while hepatic synthesis disorders are evident in coagulopathy, hyperbilirubinemia, hypoalbuminemia, etc. The portal hypertension that chronic processes generate is characterized by splenomegaly, platelet count and digestive haemorrhage through oesophageal varices. The cause that originates the liver failure will determine the way it presents. In the acute form the patients present coagulopathy and encephalopathy, while in the chronic form the ascites, the abdominal bleeding, and the malnutrition predominate.
This is the most frequent cause worldwide. The origin of the cirrhosis divides patients in two groups: the hepatocellular group, mainly in adults, as a chronic viral infection of virus C, autoimmune and alcoholism; or the colestatic group, mainly in children, as biliary atresia, Alagille syndrome and errors of metabolism of the bile salts, primary biliary cirrhosis (in adults) and sclerosing cholangitis.
It is defined as the sudden onset of coagulopathy with or without encephalopathy after the appearing of jaundice in a patient with no chronic pathology previously known. It is more frequent in pediatric age and it represents the second cause of liver transplant in Argentina. The most frequent aetiology is the infection caused by the virus of hepatitis A (in decline after the mandatory vaccine in 2005) or undetermined (first cause in adult patients) followed by autoimmune hepatitis, Wilson disease, and the intake of drugs (acetaminophen); these last ones are found in both age groups.
The hepatocelularThe Hepatocellular carcinoma is the hepatic tumor that most frequently requires a transplant in adults. It is considered as a secondary complication of cirrhosis in 60% of cases, other aetiologies as hemochromatosis, tyrosinemia in children, and the B virus, among others, can also be the cause. In general it can be found in cirrhotic patients with good liver function. Even though the best results classically are obtained with single small lobular tumors, (Milan criteria), nowadays the expansion of this criteria presents promising results a priori.
The hepatoblastoma that is not resolved with chemotherapy and surgery is the liver tumor that is most frequently transplanted in children, achieving a survival rate of almost 90%.
Exceptionally other tumors are indicated for transplant: malign tumors in patients without cirrhosis as the hemangioendotelioma epiteloide, the variant fibrolamelar of the hepatocarcinoma, the massive metastasis of neuroendocrine tumors and in selected patients the cholangiocarcinoma.
Son más frecuentes en la edad pediátrica y tienen la particularidad de corregir en forma parcial o total el daño producido en otros órganos. Las enfermedades más frecuentes son: el déficit de alfa-1-antitripsina, la hipercolesterolemia primaria, la galactosemia, la hiperoxaluria primaria etc.
En los adultos la polineuropatía amiloidótica familiar es el defecto metabólico más frecuente.
The mere presence of chronic hepatic disease is not indication for transplant. Some patients with compensated cirrhosis have less mortality risk than with the transplant, while the uncompensated cirrhosis have bad prognosis without the transplant. The adaptation of the risk score MELD (“Model of End-stage Liver Disease”) and its pediatric variation PELD, that measures the probability of mortality in cirrhotic patients in a three-month period, has managed to quantitatively stratify the risk of death and it is the tool used to arrange the waiting list of patients of cadaveric organs.
A correct evaluation of a candidate for a liver transplant must not only assess the functioning of the rest of the organs: respiratory sufficiency, cardiac function and coronary and renal disease, viral replication (C virus and HIV), but also has to establish the probable contraindications of the procedure.
(Gentileza: INCUCAI ARGENTINA)