Analyses of the risk and operative stress for donors in living-related partial liver transplantation

Pathologic Analysis of Right-Lobe Graft Failure in Adult-to-Adult Live Donor Liver Transplantation

Live donor adult liver transplantation (LDALT) utilizing right-lobe grafts is now acceptable as an alternative to cadaveric orthotopic liver transplantation (OLT). However, some LDALTs fail and require urgent OLT or result in recipient death. Our aim was to determine the basis of LDALT failure. Liver specimens from 49 LDALT recipients were evaluated and the findings correlated with clinical outcome. Ten patients (20.4%) had either early (< 1 month) or late (> 1 month) graft failure. Eight early failures, 7 of which occurred among our first 25 cases, were due to extensive liver parenchymal necrosis as a result of hepatic artery thrombosis (n=3), portal vein thrombosis (n= 1), hyperperfusion syndrome (n= 1), complete graft thrombosis (n= 1) with Factor V Leiden on a regimen of therapeutic heparin (n=1), sepsis and concomitant graft dysfunction with venous outflow tract injury (n=I), and venous outflow tract thrombosis and parenchymal thermal injury with sepsis (n=1). Preoperative, intraoperative, or postoperative severe vessel wall injury was evident in 6/8 early failures. TWo patients had late graft failure, 1 from recurrent hepatitis C and 1 with sepsis/multisystem organ failure. There were no significant differences in graft size, rejection episodes, or operative or ischemic times between patients with and without graft failure. In conclusion, LDALT failed in 10/49 (20%) of our patients, with 8/10 occurring within 1 month post-LDALT owing to vascular/thrombotic complications experienced during the early phase of our institutional experience. Perioperative vessel wall injury appeared to be a major factor in predicting early graft loss.

Ethics Committees at Work

The Research Center for Surgery (RCS) in Moscow is recognized as one of the largest and most prestigious surgical institutions in Russia. In this 400-bed facility more than 3,000 surgical procedures are performed annually, including heart, liver, and pancreas interventions and the reimplantation of limbs. The main focus of the research program at the RCS is on the transplantation of organs and reconstructive surgery. All procedures are free of charge to the patient.

Microsurgical reconstruction of hepatic artery during living donor liver transplantation

Living donor liver transplantation (LDLT) has become a well-recognized treatment modality for patients with end-stage liver disease. Arterial reconstruction during LDLT is perhaps the most important aspect of the grafting procedure. Although microsurgical hepatic artery reconstruction has become the essential technique in LDLT, it poses significant challenges even to experienced microsurgeons. In this report, the experiences of 155 microsurgical reconstructions of the hepatic artery in 150 LDLTs were reviewed, and the problems that were encountered and the solutions are discussed. From June 1999-March 2004 150 LDLTs were performed on 148 recipients at Ege University Organ Transplantation and Research Center. Hepatic arterial thrombosis was encountered in 3 patients. Microsurgical technique has overcome the difficulties in LDLT. This has increased liver transplantations in the presence of limited cadaver grafts and has decreased the patient mortality in the waiting list.

Stress response to hepatectomy in patients with a healthy or a diseased liver

Partial hepatectomy is a major upper abdominal operation associated with certain stress to the patient. Successful adaptation to such stress is a prerequisite for survival. Donor hepatectomy with maximal safety is a principal concern during living donor liver transplantation. The purpose of the study was to compare the stress response by assessing cytokines and the acute-phase response induced by hepatectomy in patients with a healthy liver and those with a diseased liver. Fourteen patients undergoing partial right hepatectomy were enrolled in this study. Seven of them were donors for living related liver transplantation (group 1, or GI); the other seven were patients with hepatocellular carcinoma due to chronic hepatitis B (Child's class A) (GII). Blood samples for interleukin-6 (IL-6), tumor necrosis factor-alpha (TNFalpha), and C-reactive protein (CRP) assays were collected before the operation, at the beginning and end of the operation, and 24 and 48 hours after the operation. The data were analyzed and compared in the same group using the Friedman test and between groups using the Mann-Whitney U-test. A value of p < 0.05 was regarded as significant. Results showed that resection of the liver in patients with both healthy and disease livers leads to significant increases in IL-6 and CPR but not TNFalpha. Significantly lower levels of IL-6 before and after operation in GI patients compared to those in GII patients suggests that GI patients adapted to surgical stress more easily than did the GII patients.

Living donor liver transplantation: summary of a conference at The National Institutes of Health

Living donor liver transplantation for adults was developed only recently in an attempt to increase the pool of donor organs; to reduce morbidity and mortality; and to improve the long-term survival of patients in need of liver transplant. Within a few brief years, this procedure has gained widespread support by both the public and transplant community. The procedure will soon be performed by nearly 80% of all liver transplant programs in the United States. Unfortunately, the long-term risks of the procedure to the recipient and especially the donor remain undefined. In response to the rapid growth and enthusiasm for this procedure, the National Institutes of Health sponsored a workshop, the goals of which were to review the scientific, medical, and nonmedical issues associated with living donor liver transplantation, and to define questions for future basic and clinical investigations which could improve the success and applicability of this procedure.

Graft size assessment and analysis of donors for living donor liver transplantation using right lobe

BACKGROUND

Modality of living donor liver transplantation (LDLT) has been expanded to adult cases. However, the safety of right lobectomy from living donors has not yet been proven.

METHODS

A total of 62 cases of LDLT, using the right lobe, were reviewed. Study 1: Discrepancy between estimated graft volume and actual graft weight was evaluated. Study 2: Postoperative liver functions were analyzed in relation to residual liver volume (RLV) or age. Residual liver volume of donors was defined using two indices, (RLV = estimated whole liver volume - estimated graft volume and %RLV = RLV/estimated whole liver volumex100). Donors were divided into two groups on the basis of either %RLV (<40%; 40%< or =) or age (<50 years old; 50 years old < or =). Study 3: Right lobe donors were compared with left lobe donors (35 cases) in terms of their postoperative liver functions.

RESULTS

Study 1: The relationship between estimated graft volume and actual graft weight was linear (y=159.136+0.735x, R2=0.571, P<0.001). Study 2: %RLV ranged from 23.5% to 55.8% (mean +/- SD: 43.2+/-6.0). Fifteen cases showed %RLV less than 40%. Postoperative bilirubin clearance was delayed in that group (%RLV<40%). Serum total bilirubin values on postoperative day 7 in the older group (age > or =50) were significantly higher than those in the younger group (age<50). Study 3: Postoperative liver functions of right lobe donors were significantly higher than those of left-lobe donors. Eleven donors (17.7%) had surgical complications, all of which were cured with proper treatment.

CONCLUSIONS

Right lobectomy from living donors is a safe procedure with acceptable morbidity, but some care should be taken early after the operation for donors with small residual liver and aged donors.

Guidelines for donor selection and an overview of the donor operation in living related liver transplantation

Guidelines for donor selection and an overview of the donor operation are reported on the basis of our experience with 120 cases of living related liver transplantation (LRLT) in pediatric patients. Once the parents had clearly expressed their desire to serve as donors, tests were performed to functionally and anatomically screen the donor livers to determine whether or not the parents' general physical condition allowed them to serve as donors. We then evaluated which of the two parental candidates was more suitable as a donor. The wishes of the family as to which parent should serve as donor was considered secondary and taken into account only in a few cases in which certain functional and/or anatomical abnormalities were uncovered that made the prime candidate less suitable. For the 120 LRLTs, 135 candidates were evaluated as potential donors, 15 (11.1%) of whom were rejected for various reasons. The mean volume of blood loss during the donor operation decreased significantly from 489 g in the first 60 LRLTs to 390 g in the latter 60 LRLTs; this was accompanied by a significant decrease in the mean volume of autologous blood transfused from 449 g to 390 g. Mean cold ischemia time of the graft increased significantly from 71.4 to 128.0 min, while mean operation time conversely decreased from 6.7 to 6.2 h. Bile leakage from the cut surface of the remnant liver, which was the only post-operative surgical complication encountered, was noted in five cases. We conclude that donor candidates should be strictly selected according to basic guidelines, taking into account both the results of preoperative screening and the wishes of the family. With this accumuled experience, we have been able to simplify our LRLT operative procedure, resulting in decreases in blood loss volume, blood transfused, and operation time.

Guidelines for donor selection and an overview of the donor operation in living related liver transplantation

Guidelines for donor selection and an overview of the donor operation are reported on the basis of our experience with 120 cases of living related liver transplantation (LRLT) in pediatric patients. Once the parents had clearly expressed their desire to serve as donors, tests were performed to functionally and anatomically screen the donor livers to determine whether or not the parents' general physical condition allowed them to serve as donors. We then evaluated which of the two parental candidates was more suitable as a donor. The wishes of the family as to which parent should serve as donor was considered secondary and taken into account only in a few cases in which certain functional and/or anatomical abnormalities were uncovered that made the prime candidate less suitable. For the 120 LRLTs, 135 candidates were evaluated as potential donors, 15 (11.1%) of whom were rejected for various reasons. The mean volume of blood loss during the donor operation decreased significantly from 489 g in the first 60 LRLTs to 390 g in the latter 60 LRLTs; this was accompanied by a significant decrease in the mean volume of autologous blood transfused from 449 g to 390 g. Mean cold ischemia time of the graft increased significantly from 71.4 to 128.0 min, while mean operation time conversely decreased from 6.7 to 6.2 h. Bile leakage from the cut surface of the remnant liver, which was the only post-operative surgical complication encountered, was noted in five cases. We conclude that donor candidates should be strictly selected according to basic guidelines, taking into account both the results of preoperative screening and the wishes of the family. With this accumuled experience, we have been able to simplify our LRLT operative procedure, resulting in decreases in blood loss volume, blood transfused, and operation time.

Experiences of 120 microsurgical reconstructions of hepatic artery in living related liver transplantation

BACKGROUND

We reviewed 120 microsurgical reconstructions of a hepatic artery in living related liver transplantation and discussed the problems encountered.

METHODS

From January 1991 to July 1994 we performed a series of 105 living related liver transplantations on children with end-stage liver disease. Arterial reconstruction was performed under the optical field of a continuous zoom magnification of approximately 10 times with an operating microscope.

RESULTS

Twenty-six percent of the graft arteries were less than 2 mm in diameter. The time required for an arterial reconstruction was 49.5 +/- 1.8 minutes. In 15 of the 31 cases in which there were two graft arteries, two arterial reconstructions were required. The caliber differences between the graft artery and the recipient artery in 30 instances was dealt with by cutting an undersized artery obliquely (17 instances), by fish-mouth method (10 instances), by end-to-side anastomosis (1 instance), or by funnelization method (2 instances). In one case we performed an intimal dissection of a recipient hepatic artery and substituted a splenic artery. Consequently, hepatic arterial thrombosis occurred in only two cases (1.7%).

CONCLUSIONS

Microsurgical technique has overcome the high risk of hepatic arterial thrombosis in cases of fine graft arteries, enabled the reconstruction of arteries with caliber difference, and decreased arterial complications with its delicate manipulation.

Intraoperative measurement of the graft oxygenation state in living related liver transplantation by near infrared spectroscopy

Graft oxygenation plays an important role in successful liver transplantation. Intraoperative changes in the oxygenation state of the liver graft were measured by near infrared spectroscopy in 28 cases of living related liver transplantation. Oxygen saturation of hemoglobin in the liver (hepatic SO2) changed from 81.2% +/- 1.5% (mean +/- SEM) before donation (in the donor) to 49.7% +/- 4.2% after portal reflow, to 58.4% +/- 5.0% after arterial reflow, and then to 71.4% +/- 3.9% before closure. Mean hepatic SO2 was positively correlated with portal flow rate as measured by duplex Doppler sonography. Cases with low portal flow rate showed a high coefficient of variation (SD/mean) of hepatic SO2, indicating heterogeneous tissue oxygenation. Though graft size was expected to affect the graft oxygenation state, hepatic SO2 was fairly independent of the graft-to-recipient weight ratio. In two cases with markedly low hepatic SO2, postoperative graft dysfunction occurred. This study suggest that the method of near infrared spectroscopy is reliable and useful for assessing the graft oxygenation state in liver transplantation.

Living related liver transplantation in children

We reviewed 37 living related liver transplantations (LRLT) performed by our department during the last 27 months on children with end-stage liver disease. The patients were 15 boys and 22 girls aged 7 months to 15 years with biliary atresia (27), cryptogenic cirrhosis (3), Budd-Chiari syndrome (2), progressive intrahepatic cholestasis (2), protoporphyria (1), Wilson's disease (1), and fulminant hepatitis (1). The donors were 14 fathers and 23 mothers. Grafts were made from the left lateral segment (19), left lateral segment with partial S4 (11), left lobe (6), and right lobe (1). After graft harvesting all donors resumed normal liver function and normal life. The recipient underwent total hepatectomy with preservation of the inferior vena cava. FK506 and low-dose steroids were used for immunosuppression. The survival rate was 90% (27/30) in elective cases and 57% (4/7) in emergency cases. Six recipients had functioning grafts but died of extrahepatic complications. Hepatic vein stenosis occurred in 3 cases at 3 months after LRLT and was successfully treated by balloon dilatation. Portal vein stenosis occurred in 1 case at 8 months after LRLT and was also safely dilated. We incurred no hepatic artery thrombosis after introducing microsurgery techniques. Among 12 viral, 5 bacterial, and 3 fungal postoperative infections, 1 Candida pneumonia and 1 EBV-associated lymphoma were lethal. Three patients with ABO-blood group compatible grafts and one with an incompatible graft developed acute rejection, which was controlled in evey case by steroid bolus and/or increasing the dose of FK506. There were no definite episodes of rejection in ABO-identical cases. Children with moderate growth retardation (> or = -1.5 SD of normal growth) caught up in growth soon after LRLT, but those with severe retardation (<-1.5 SD) were slow to attain age-normal height. Appropriate timing, meticulous surgical procedures, and comprehensive management of complications are crucial for successful outcome with LRLT. LRLT is a promising option for alleviating the shortage of livers for pediatric transplantation and may be regarded as an independent modality to supplement cadaver donation.

Liver transplantation from living related donors: review of world experience and its implications for India

Living related liver transplantation (LRLT) was made possible because of a better understanding of the anatomy of the liver and advances made in hepatic surgical techniques. It was developed to reduce the waiting period for pediatric recipients. In countries like Japan, which do not have brain stem death legislation, LRLT is the only modality available for treating end stage liver disease. The world experience has shown that LRLT has been successfully performed in a variety of conditions leading to acute and chronic liver failure not only in children, but in young adults as well. The initial results of LRLT appear to be better than liver transplantation from cadaveric organs in terms of graft survival and function. Donor safety has been of prime concern. LRLT has tremendous potential in India with or without the brain stem death legislation. Liver transplantation has not been performed in India although the need and expertise for it exists.

Delayed oxidation of intramitochondrial pyridine nucleotide oxidoreduction state as compared with tissue oxygenation in human liver transplantation

Intra- and post-operative oxygenation of graft liver and subsequent oxidation of the intramitochondrial oxido-reduction state of pyridine nucleotide were studied in partial liver transplantation from living related donors with the ratio of acetoacetate to beta-hydroxybutyrate in arterial blood (AKBR), the ratio of oxidized flavoprotein to reduced pyridine nucleotide (FP/PN ratio) and oxygen saturation of hemoglobin in liver tissue (hepatic SO2). Decreased hepatic SO2 and its heterogenous distribution after reflow of portal vein and hepatic artery were normalized by the end of operation, while the intramitochondrial oxido-reduction state was still reduced at the end of operation and was normalized only at 24 h after the operation. The observed delay in oxidation of the intramitochondrial oxido-reduction state as compared with tissue oxygenation indicates the transition of the intramitochondrial oxido-reduction state associated with the initiation of metabolic activity from the cold preserved state, and suggests an important role for microcirculation in the normalization of the oxido-reduction state.

Short-term changes in lipid and protein metabolism in liver transplants from living-related donors

The effects of liver transplantation involving living-related donors were investigated in 20 pediatric cases in terms of protein and lipid metabolism using the extent of cholesterol esterification and the levels of total cholesterol, lecithine-cholesterol acyltransferase, apolipoprotein A-I, cholinesterase, and rapid turnover proteins as parameters. Cholesterol esterification increased from preoperative values of 39% +/- 4% to 67% +/- 1% (mean +/- SEM, n = 17) at 3 weeks after liver transplantation in successful cases but decreased from the preoperative value of 45% +/- 10% to 26% +/- 6% (n = 3) at 3 weeks in unsuccessful cases. Cholinesterase, transferrin, and prealbumin levels remained low after 3 weeks even in successful cases. Patients who had partial liver transplantations from living-related donors showed rapid recovery of cholesterol esterification. However, patients with graft livers required an extensive period before normalization of protein metabolism occurred, indicating the necessity for long-term follow-up of recipient development.