RISK FACTORS ASSOCIATED WITH HEPATIC ARTERY THROMBOSIS: ANALYSIS OF 1050 LIVER TRANSPLANTS

Prediction of hepatic artery occlusion after liver transplantation by ultrasound characteristics and clinical risk factors

BACKGROUND

Hepatic artery occlusion (HAO) after liver transplantation (LT) is a devastating complication, resulting in early graft loss and reduced overall survival. Ultrasound is an established assessment method for HAO in patients following LT, especially those with complex hepatic artery reconstruction.

AIM

To investigate the ultrasound characteristics and analyze the risk factors associated with HAO in patients after LT.

METHODS

We retrospectively analyzed the ultrasound characteristics and the clinic risk factors associated with HAO in 400 adult LT patients who were enrolled and treated at the Third People's Hospital of Shenzhen between November 2016 and July 2022. Fourteen patients diagnosed with acute HAO (A-HAO) by surgery and fifteen diagnosed with chronic HAO (C-HAO) were included. A control group of 33 patients without HAO complications during the same period were randomly selected using a random number table. All patients underwent an ultrasonography examination. Parameters including resistance index (RI), peak systolic velocity (PSV), and portal vein velocity (PVV) were compared across the groups. Additionally, basic clinical data were collected for all patients, including gender, age, primary diagnosis, D-dimer concentration, total operation time, cold ischemia time, hot ischemia time, intraoperative blood loss and transfusion, intraoperative urine volume, infusion, model for end-stage liver disease (MELD) score, and whether complex hepatic artery reconstructions were performed. Furthermore, risk factors influencing HAO formation after LT were analyzed.

RESULTS

Compared to the non-HAO group, PVV and RI were higher in the A-HAO group, while PSV was lower. Conversely, both PSV and RI were lower in the C-HAO group compared to the non-HAO group. The proportion of patients undergoing complex hepatic artery reconstructions and the gamma-glutamyltransferase (GGT) level before occlusion were significantly higher in the A-HAO group compared to the non-HAO group. However, there were no distinct differences between the two groups in D-dimer, MELD score, pre-occlusion alanine transaminase and aspartate transaminase levels, or intraoperative conditions.

CONCLUSION

Ultrasound features of the hepatic artery before occlusion are significantly associated with postoperative HAO development. Additionally, complex hepatic artery reconstructions, defined as revascularization of the graft requiring additional anastomosis between donor hepatic arteries, constitute a risk factor for A-HAO. Besides, abnormal pre-occlusion GGT elevation is an important biochemical indicator. Therefore, ultrasound examination serves as an important tool for screening HAO, especially in patients with the identified risk factors.

THE OPTIMUM LEVEL OF MELD TO MINIMIZE THE MORTALITY ON LIVER TRANSPLANTATION WAITING LIST, AND LIVER TRANSPLANTED PATIENT IN SÃO PAULO STATE, BRAZIL

BACKGROUND

After validation in multiple types of liver disease patients, the MELD score was adopted as a standard by which liver transplant candidates with end-stage liver disease were prioritized for organ allocation in the United States since 2002, and in Brazil, since 2006.

AIMS

To analyze the mortality profile of patients on the liver transplant waiting list correlated to MELD score at the moment of transplantation.

METHODS

This study used the data from the Secretary of Health of the São Paulo State, Brazil, which listed 22,522 patients, from 2006 (when MELD score was introduced in Brazil) until June 2009. Patients with acute hepatic failure and tumors were included as well. We also considered the mortality of both non-transplanted and transplanted patients as a function of the MELD score at presentation.

RESULTS

Our model showed that the best MELD score for patients on the liver transplant waiting list associated to better results after liver transplantation was 26.

CONCLUSIONS

We found that the best score for applying to liver transplant waiting list in the State of São Paulo was 26. This is the score that minimizes the mortality in both non-transplanted and liver transplanted patients.

A Single-Center's Early Surgical Outcomes of Living Donor Liver Transplantation

BACKGROUND

Living donor liver transplantation (LDLT) has become an increasingly common surgical option because the number of cadaveric donors is insufficient to fulfill the organ needs of patients facing end-stage cirrhosis. Many centers are investigating different surgical techniques to achieve lower complication rates. We aimed to examine our complication rates in light of demographic data, graft data, and perioperative findings as a single-center experience.

METHODS

The study included one hundred and three patients who underwent LDLT for end-stage liver cirrhosis. Demographic data; sex; age; blood group; Model for End-Stage Liver Disease score; Child score; etiology; liver side; graft-to-recipient weight ratio; hepatic artery, portal vein, and bile anastomosis type rates; anhepatic phase; cold ischemia time; operation time; and blood product transfusion rates were analyzed. Biliary complications in patients with single or multiple biliary anastomoses, right or left liver transplants, and with or without hepatic artery thrombosis were analyzed statistically.

RESULTS

There was no significant difference in biliary complications between patients who underwent single or multiple bile anastomosis (P = .231) or patients receiving right lobe and left lobe transplants (P = .315). Although there was no statistically significant difference in the rate of portal vein thrombosis between the regular and reconstructed portal vein anastomosis groups (P = .693), the postoperative portal vein thrombosis rate was statistically higher in patients with left lobe transplants (P = .044).

CONCLUSIONS

Vascular and biliary complication rates can be reduced with increasing experience.

INDICATION FOR LIVER TRANSPLANTATION DUE TO HEPATOCELLULAR CARCINOMA: ANALYSIS OF 1,706 PROCEDURES OVER THE PAST DECADE IN THE STATE OF PARANÁ

BACKGROUND

Patients listed for liver transplantation and hepatocellular carcinoma are considered priority on the waiting list, and this could overly favor them.

AIM

This study aimed to evaluate the impact of this prioritization.

METHODS

We analyzed the liver transplants performed in adults from 2011 to 2020 and divided into three groups: adjusted Model of End-Stage Liver Disease (MELD) score for hepatocellular carcinoma, other adjusted Model of End-Stage Liver Disease situations, and no adjusted Model of End-Stage Liver Disease.

RESULTS

A total of 1,706 patients were included in the study, of which 70.2% were male. Alcoholism was the main etiology of cirrhosis (29.6%). Of the total, 305 patients were with hepatocellular carcinoma, 86 with other adjusted Model of End-Stage Liver Disease situations, and 1,315 with no adjusted Model of End-Stage Liver Disease. Patients with hepatocellular carcinoma were older (58.9 vs. 53.5 years). The predominant etiology of cirrhosis was viral hepatitis (60%). The findings showed that group with adjusted Model of End-Stage Liver Disease had lower physiological Model of End-Stage Liver Disease (10.9), higher adjusted Model of End-Stage Liver Disease (22.6), and longer waiting list time (131 vs. 110 days), as compared to the group with no adjusted Model of End-Stage Liver Disease. The total number of transplants and the proportion of patients transplanted for hepatocellular carcinoma increased from 2011 to 2020. There was a reduction in the proportion of patients with hepatocellular carcinoma and adjusted Model of End-Stage Liver Disease of 20 and there was an increase on waiting list time in this group. There was an increase in the proportion of those with adjusted Model of End-Stage Liver Disease of 24 and 29, but the waiting list time remained stable.

CONCLUSION

Over the past decade, prioritization of hepatocellular carcinoma resulted in an increased proportion of transplanted patients in relation to those with no priority. It also increased waiting list time, requiring higher adjusted Model of End-Stage Liver Disease to transplant an organ.

Prädiktoren für erfolgreiche Lebertransplantationen und Risikofaktoren

Die Lebertransplantation ist die einzige kurative Therapieoption einer chronischen Leberinsuffizienz im Endstadium. Daneben stellen onkologische Lebererkrankungen wie das HCC eine weitere Indikation für die Lebertransplantation dar, ebenso wie das akute Leberversagen.

Seit der ersten erfolgreichen Lebertransplantation durch Professor Thomas E. Starzl im Jahr 1967 haben sich nicht nur die chirurgischen, immunologischen und anästhesiologischen Techniken und Möglichkeiten geändert, sondern auch die Indikationen und das Patientengut. Hinzu kommt, dass die Empfänger ein zunehmendes Lebensalter und damit einhergehend mehr Begleiterkrankungen aufweisen.

Die Zahl an Lebertransplantationen ist weltweit weiter ansteigend. Es benötigen aber mehr Menschen eine Lebertransplantation, als Organe zur Verfügung stehen. Dies liegt am zunehmenden Bedarf an Spenderorganen bei gleichzeitig weiter rückläufiger Zahl postmortaler Organspenden.

Diese Diskrepanz zwischen Spenderorganen und Empfängern kann nur zu einem kleinen Teil durch Split-Lebertransplantationen oder die Leberlebendspende kompensiert werden.

Um den Spenderpool zu erweitern, werden zunehmend auch marginale Organe, die nur die erweiterten Spenderkriterien („extended donor criteria [EDC]“) erfüllen, allokiert. In manchen Ländern zählen hierzu auch die sogenannten DCD-Organe (DCD: „donation after cardiac death“), d. h. Organe, die erst nach dem kardiozirkulatorischen Tod des Spenders entnommen werden.

Es ist bekannt, dass marginale Spenderorgane mit einem erhöhten Risiko für ein schlechteres Transplantat- und Patientenüberleben nach Lebertransplantation einhergehen.

Um die Qualität marginaler Spenderorgane zu verbessern, hat sich eine rasante Entwicklung der Techniken der Organkonservierung über die letzten Jahre gezeigt. Mit der maschinellen Organperfusion besteht beispielsweise die Möglichkeit, die Organqualität deutlich zu verbessern. Insgesamt haben sich die Risikokonstellationen von Spenderorgan und Transplantatempfänger deutlich geändert.

Aus diesem Grunde ist es von großer Bedeutung, spezifische Prädiktoren für eine erfolgreiche Lebertransplantation sowie die entsprechenden Risikofaktoren für einen schlechten postoperativen Verlauf zu kennen, um das bestmögliche Transplantat- und Patientenüberleben nach Lebertransplantation zu ermöglichen.

Diese Einflussfaktoren, inklusive möglicher Risiko-Scores, sollen hier ebenso wie die neuen technischen Möglichkeiten in der Lebertransplantation beleuchtet werden.

PROTOCOL FOR LIVER TRANSPLANTATION IN HILAR CHOLANGIOCARCINOMA

Background:

Hilar cholangiocarcinoma represents more than half of all cholangiocarcinoma cases, having poor prognosis and presenting a median overall survival after diagnosis of 12-24 months. In patients who have unresectable tumors with a better prognosis, the proposal to perform liver transplantation emerged for expanding the possibility of free margins by performing total hepatectomy.

Aim:

To provide a Brazilian protocol for liver transplantation in patients with hilar cholangiocarcinoma.

Method:

The protocol was carried out by two Brazilian institutions which perform a large volume of resections and liver transplantations, based on the study carried out at the Mayo Clinic. The elaboration of the protocol was conducted in four stages.

Result:

A protocol proposal for this disease is presented, which needs to be validated for clinical use.

Conclusion:

The development of a liver transplantation protocol for cholangiocarcinoma aims not only to standardize the treatment, but also enable a better assessment of the surgical results in the future.