The current status of living donor liver transplantation

Human mesenchymal stromal cell lysates as a novel strategy to recover liver function

AIM

It is unknown if the beneficial effects of mesenchymal stromal cells (MSC) transplantation into the liver are dependent on their anchorage and differentiation into hepatocytes or rather the result of the release of stem cell intracellular content with hepatoprotector properties.

MATERIALS & METHODS

The effects of intact MSC transplantation were compared with the infusion of MSC lysates in an experimental rat model of acute liver failure.

RESULTS

A more powerful hepatoprotective and antiapoptotic effect was obtained after infusion of MSC lysates than intact MSC. Changes in IL-6 levels and miRNAs might explain the beneficial effects of MSC lysates.

CONCLUSION

Infusion of MSC lysates show a better hepatoprotective effect than the transplantation of intact MSC.

A graft to body weight ratio less than 0.8 does not exclude adult-to-adult right-lobe living donor liver transplantation

Many centers require a minimal graft to body weight ratio (GBWR) >or= 0.8 as an arbitrary threshold to proceed with right-lobe living donor liver transplantation (RL-LDLT), and there is often hesitancy about transplanting lower volume living donor (LD) liver grafts into sicker patients. The data supporting this dogma, based on the early experience with RL-LDLT at Asian centers, are weak. To determine the effect of LD liver volume in the modern era, we investigated the impact of GBWR on the outcome of RL-LDLT with a GBWR as low as 0.6 at the University of Toronto. Between April 2000 and September 2008, 271 adult-to-adult RL-LDLT procedures and 614 deceased donor liver transplants were performed. Twenty-two living donor liver transplantation (LDLT) cases with a GBWR of 0.59 to 0.79 (group A) were compared with 249 LDLT cases with a GBWR >or= 0.8 (group B) and with 66 full-graft deceased donor liver transplants (group C), who were matched 3:1 according to donor and recipient age, Model for End-Stage Liver Disease score, and presence of hepatitis C and hepatocellular carcinoma with the low-GBWR group. Portal vein shunts were not used. Markers of reperfusion injury [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)], graft function (international normalized ratio and bilirubin), complications graded by the Clavien score, and graft and patient survival were compared. As expected, LD recipients had a significantly shorter cold ischemia time (94 +/- 43 minutes for A, 96 +/- 57 minutes for B, and 453 +/- 152 minutes for C, P = 0.0001). However, the peak AST, peak ALT, absolute decrease in the international normalized ratio, day 7 bilirubin level, postoperative creatinine clearance, complication rate graded by the Clavien score, and median hospital stay were similar in all groups. The rate of biliary complications was higher with LD grafts than deceased donor grafts (19% for A versus 10% for B and 0% for C, P = 0.2). Patient survival was similar in all groups at 1, 3, and 5 years (91% for A versus 89% for B and 93% for C at 1 year, 87% for A versus 81% for B and 89% for C at 3 years, and 83% for A versus 81% for B and 87% for C at 5 years, P = 0.63). A Cox proportional regression analysis revealed only hepatitis C virus as a risk factor for poorer graft survival and not GBWR as a continuous or categorical variable. In conclusion, we found no evidence of inferior outcomes with smaller size grafts versus larger size LD grafts or full-size deceased donor grafts. Further studies are warranted to examine the factors affecting the function of smaller grafts for living liver donation and thereby define the safe lower limits for transplantation.

Liver transplantation: from Child to MELD

The widespread availability of transplantation in most major medical centers in the United States, together with a growing number of transplant candidates, has made it necessary for primary care providers, especially internal medicine and family practice physicians to be active in the clinical care of these patients before and after transplantation. This review provides an overview of the liver transplantation process, including indications, contraindications, time of referral to a transplant center, the current organ allocation system, and briefly touches on the expanding field of living donor liver transplantation.

[The role of imaging methods in the pre- and intra-operative evaluation, and in post-operative follow-up of living donors in liver transplantation in Hungary]

The evaluation protocol for liver donors can vary from centre to centre, but the main points are the same. Medical history, physical examination, common laboratory tests and psychosocial evaluation are followed by imaging, and specific haemostasis and viral serology tests. The first imaging examinations have the aim of excluding any disease; conventional chest radiography and abdominal ultrasound are performed. Liver volume, fat content, and vascular and biliary anatomy are then evaluated with contrast-enhanced, multiphase, multidetector row CT/CTA and MR cholangiography. Ultrasound guided liver biopsy, and in some cases digital subtraction angiography, should also be performed. During the first phase of the donor operation, intraoperative investigations are done: cholangiography for the final evaluation of the biliary tree and ultrasound of the hepatic and portal venous system to help draw the resection plane. Donors have regular imaging examinations in the early postoperative period for early detection of complications: mainly US or CT to check the remnant hepatic vascularisation and fluid collections in the operated area, or X-ray for thoracic disorders. It is recommended that regular checkups are performed in the late postoperative period. The paper describes the imaging protocol for donor evaluation applied at our institute at the beginning of our living related liver transplantation programme.

Preliminary experience in adult-to-adult living donor liver transplantation in a single center in China

The aim of this paper is to report the authors' experience in performing adult-to-adult living donor liver transplantation (LDLT) by using a modified technique in using grafts of the right lobe of the liver. From January 2002 to September 2006, 56 adult patients underwent LDLT using right lobe grafts at the West China Hospital, Sichuan University Medical School, China. All patients underwent a modified operation designed to improve the reconstruction of the right hepatic vein (RHV) and the tributariers of the middle hepatic vein (MHV) by interposing a vessel graft, and by anastomosing the hepatic arteries and bile ducts. There were no severe complications or deaths in all donors. Fifty-two (92.8%) recipients survived the operations. Among the 56 recipients, complications were seen in 15 recipients (26.8%), including hepatic vein stricture (one case), small-for-size syndrome (one case), hepatic artery thrombosis (two cases), intestinal bleeding (one case), bile leakage (two cases), left subphrenic abscess (one case), renal failure (two cases) and pulmonary infection (five cases). Within three months after transplantation, four recipients (7.14%) died due to small-for-size syndrome (one case), renal failure (one case) and multiple organ failure (two cases). All patients underwent direct anastomoses of the RHV and the inferior vena cava (IVC), and in 23 cases, reconstruction of the right inferior hepatic vein was also done. In 24 patients, the reconstruction of the tributaries of the MHV was also done by interposing a vessel graft to provide sufficient venous outflow. Trifurcation of the portal vein was seen in nine cases. Thus, veno-plasty or separate anastomoses were performed. The graft and recipient body weight ratios (GRWR) were between 0.72% and 1.43%, and in three cases it was <0.8%. The graft weight to recipient standard liver volume ratios (GV/SLV) were between 31.86% and 71.68%, among which four cases had <40%. No "small-for-size syndrome" occurred. With modification of the surgical technique, especially in the reconstruction of the hepatic vein to provide sufficient venous outflow, living donor liver grafts in adults using the right lobe of the liver can become a relatively safe procedure and prevent the "small-for-size syndrome".

Posttransplant diabetes mellitus in liver transplant recipients

CONTEXT

Approximately 20% of liver transplant recipients develop posttransplant diabetes mellitus. Hepatitis C, a leading indication for liver transplantation, has been identified as a risk factor for posttransplant diabetes mellitus and is an observation that is not well described.

OBJECTIVE

To evaluate the incidence of posttransplant diabetes mellitus and risk factors associated with this condition.

DESIGN

A retrospective chart review.

SETTING

A large urban transplant center.

PATIENTS

One hundred fifteen liver transplant recipients who received a transplant between January 1, 1998, and August 31, 2001.

RESULTS

The rate of posttransplant diabetes mellitus, calculated at 3-month intervals in the first year after liver transplantation, ranged from 19.4% to 24.6%, which is similar to the averages reported in most published studies. The cumulative rate of posttransplant diabetes mellitus, which includes all patients who developed this condition during the time studied, was 31.3%. Clinical and demographic factors, including immunosuppression regimens, were similar between patients with and without posttransplant diabetes mellitus. Two risk factors for posttransplant diabetes mellitus were identified: hepatitis C, which was the leading indication for transplantation in this group (54.8%), and cytomegalovirus infection during the first year after transplantation. Other clinical and demographic variables, such as gender, age, ethnicity, rejection episodes, body mass index, and immunosuppression, were not identified as risk factors for posttransplant diabetes mellitus in liver transplant recipients.