Eishi Totsuka

Porcine partial liver transplantation: A novel model of the “small‐for‐size” liver graft

Increasing shortage of cadaveric grafts demands the utilization of living donor and split liver grafts. The purpose of this study was to 1) define the “small‐for‐size” graft in a pig liver transplant model 2) evaluate pathological changes associated with small‐for‐size liver transplantation. Pigs were divided into four groups based on the volume of transplanted liver: (a) control group (n=4), 100% liver volume (LV) (b) group I (n=8), 60% LV (c) group II (n=8), 30% LV (d) group III (n=15), 20% LV. Tacrolimus and methyl prednisone were administered as immunosuppression. Animals were followed for 5 days with daily serum biochemistry, liver biopsies on day 3 and 5 for light microscopy, and tissue levels of thymidine kinase (TK) and ornithine decarboxylase (ODC). Liver grafts were weighed pretransplant and at sacrifice. All the recipients of 100%, 60%, and 30% grafts survived. Transplantation of 20% grafts (group III) resulted in a 47% mortality rate. Group III animals showed significantly prolonged prothrombin times (p<0.05), elevated bilirubin levels (p<0.05), and ascites. The rate of regeneration, as indicated by TK activity and graft weight was inversely proportional to the size of the transplanted graft. The severity of the microvascular injury was inversely proportional to graft size and appeared to be the survival‐limiting injury. Frank rupture of the sinusoidal lining, parenchymal hemorrhage, and portal vein injury were prominent in group III animals 1 hour following reperfusion. This study established a reproducible large animal model of partial liver grafting; it defined the small‐for‐size syndrome in this model and described the associated microvascular injury. (Liver Transpl 2004;10:253–263.)

Protective role of nitric oxide in ischemia and reperfusion injury of the liver

Abstract Background: The suppressed production of nitric oxide (NO), associated with endothelial dysfunction, is thought to be a cause of ischemia and reperfusion injury of the liver. But findings of the salutary effects of NO enhancement on such injury have been conflicting. In this study, we tested our hypothesis that NO enhancement would attenuate ischemic liver injury. For this purpose, an NO precursor, L-arginine, and a novel NO donor, FK409, were applied to a 2-hour total hepatic vascular exclusion model in dogs. Study Design: L-arginine was administered IV at a dose of 100 mg/kg twice (n = 5), while 300 mg/kg twice of FK409 was infused continuously into the portal vein (n = 5). The drugs were given to the animals for 30 and 60 minutes before and after ischemia, respectively. Nontreated animals were used as the control (n = 10). Two-week survival, systemic and hepatic hemodynamics indices, liver function tests, energy metabolism, and histopathology were analyzed. Results: Both treatments comparably augmented hepatic tissue blood flow, decreased liver enzyme release, and increased high-energy phosphate restoration during the reperfusion period, all of which contributed to rescuing all of the treated animals from the 2-hour total hepatic ischemia. In contrast, ischemia caused 70% mortality in the control group. Histologically, structural abnormality and neutrophil infiltration were markedly attenuated by the treatments. Systemic hypotension was observed in the animals treated with FK409, however. Conclusions: Our data demonstrate that NO enhancement alleviates the liver injury caused by ischemia and reperfusion. The supplementation of L-arginine, rather than FK409, is considered more applicable to clinical use because of the absence of systemic adverse effects.

Influence of cold ischemia time and graft transport distance on postoperative outcome in human liver transplantation.

Abstract.Purpose: The association between hepatic allograft cold ischemia time (CIT) and graft transport distance (GTD) in human liver transplantation was examined by investigating whether extended graft transportation prolongs the CIT and adversely affects graft survival.Methods: We retrospectively analyzed 186 consecutive orthotopic liver transplants (OLTs) done between May 1997 and July 1998. The number of miles from the donor hospital to the University of Pittsburgh Medical Center in a straight line was measured in each case, and defined as the GTD. The OLTs were divided into two groups according to whether the GTD was ≤200 miles or >200 miles. The latter group was then subdivided into groups of GTD 200–400 miles, GTD 400–600 miles, and GTD >600 miles. The CIT and graft outcome within 90 days after OLT were assessed.Results: Extended GTD prolonged the CIT (P < 0.001). The rate of hepatic allograft loss in the long GTD group was significantly higher than that in the short GTD group (P= 0.018). When the OLTs were subdivided according to GTD, the CIT increased and graft survival decreased as the GTD extended. Hepatic allograft transportation for a long distance prolonged the CIT and decreased the graft survival rate.Conclusion: Since prolonged CIT is a major risk factor, avoiding long-distance graft transportation is recommended when the donor risk factors are high.

Attenuation of ischemic liver injury by prostaglandin E1 analogue, misoprostol, and prostaglandin I2 analogue, OP-41483

BACKGROUND Prostaglandin has been reported to have protective effects against liver injury. Use of this agent in clinical settings, however, is limited because of drug-related side effects. This study investigated whether misoprostol, prostaglandin E1 analogue, and OP-41483, prostaglandin I2 analogue, which have fewer adverse effects with a longer half-life, attenuate ischemic liver damage. STUDY DESIGN Thirty beagle dogs underwent 2 hours of hepatic vascular exclusion using venovenous bypass. Misoprostol was administered intravenously for 30 minutes before ischemia and for 3 hours after reperfusion. OP-41483 was administered intraportally for 30 minutes before ischemia (2 microg/kg/min) and for 3 hours after reperfusion (0.5 microg/kg/min). Animals were divided into five groups: untreated control group (n=10); high-dose misoprostol (total 100 microg/kg) group (MP-H, n=5); middle-dose misoprostol (50 microg/kg) group (MP-M, n=5); low-dose misoprostol (25 microg/kg) group (MP-L, n=5); and OP-41483 group (OP, n=5). Animal survival, hepatic tissue blood flow (HTBF), liver function, and histology were analyzed. RESULTS Two-week animal survival rates were 30% in control, 60% in MP-H, 100% in MP-M, 80% in MP-L, and 100% in OP. The treatments with prostaglandin analogues improved HTBF, and attenuated liver enzyme release, adenine nucleotrides degradation, and histologic abnormalities. In contrast to the MP-H animals that exhibited unstable cardiovascular systems, the MP-M, MP-L, and OP animals experienced only transient hypotension. CONCLUSIONS These results indicate that misoprostol and OP-41483 prevent ischemic liver damage, although careful dose adjustment of misoprostol is required to obtain the best protection with minimal side effects.

Attenuation of ischemic liver injury by monoclonal anti-endothelin antibody, AwETN40 ☆

BACKGROUND Enhanced production of endothelin-1 (ET-1), vasoconstrictive 21 amino acids produced by endothelial cells during ischemia and after reperfusion of the liver, is known to cause sinusoidal constriction and microcirculatory disturbances, which lead to severe tissue damage. Using a 2-hour hepatic vascular exclusion model in dogs, we tested our hypothesis that neutralization of ET-1 by monoclonal anti-ET-1 and anti-ET-2 antibody (AwETN40) abates vascular dysfunction and ameliorates ischemia/reperfusion injury of the liver. STUDY DESIGN After skeletonization, the liver was made totally ischemic by cross-clamping the portal vein, the hepatic artery, and the vena cava (above and below the liver). Veno-venous bypass was used to decompress splanchnic and inferior systemic congestion. AwETN40, 5 mg/kg, was administered intravenously 10 minutes before ischemia (treatment group, n = 5). Nontreated animals were used as controls (control group, n = 10). Animal survival, hepatic tissue blood flow, liver function tests, total bile acid, high-energy phosphate, ET-1 levels, and liver histopathology were studied. RESULTS Treatment with AwETN40 improved 2-week animal survival from 30% to 100%. Hepatic tissue blood flow after reperfusion was significantly higher in the treatment group. The treatment significantly attenuated liver enzyme release, total bile acid, and changes in adenine nucleotides. Immunoreactive ET-1 levels in the hepatic venous blood of the control group showed a significant increase and remained high for up to 24 hours after reperfusion. Histopathologic alterations were significantly lessened in the treatment group. CONCLUSIONS These results indicate that ET-1 is involved in ischemia/reperfusion injury of the liver, which can be ameliorated by the monoclonal anti-ET-1 and anti-ET-2 antibody AwETN40.

Kidney transplantation for end-stage renal failure in liver transplant recipients with hepatitis C viral infection.

Background. End-stage renal failure after successful liver transplantation (LTx) has been described in up to 5% of patients. Kidney transplantation (KTx) has been the treatment of choice in these cases. However, in recipients infected with hepatitis C virus (HCV), the augmentation of immunosuppression after KTx may result in an increased viral load. This, in turn, may adversely affect the liver allograft. Method. The present study retrospectively examined the outcome in 17 patients (3 females and 14 males, mean age 51.1±11.3 years) who received KTx after LTx. The mean interval from LTx to KTx was 57.6±32.1 months. The mean follow-up was 41.7 ±20.5 months after KTx, and 99.6±37.7 months after LTx. Sixteen of the 17 patients received tacrolimus-based immunosuppression at the time of KTx. Results. During the follow-up period, one patient underwent combined liver and kidney retransplantation 3.7 years after KTx and 12.7 years after LTx. She subsequently died secondary to primary nonfunction. Four other patients died, two of lung cancer, one of pancreatitis/sepsis, and one of severe depression leading to noncompliance. A total of 29 episodes of biopsy-proven acute renal allograft rejection (1.7 episodes/patient) were encountered and treated with steroids. Seven patients experienced a rise in liver function tests during the period of increased steroid dosage. Four patients received no treatment, and their liver function returned to baseline. The remaining three were treated with interferon. Overall 1- and 3-year actuarial patient and liver allograft survival was 88% and 71% (after renal transplantation); corresponding 1- and 3-year actuarial graft survival was 88% and 61%. Twelve patients are alive with normal liver function. One patient is on dialysis, because of renal allograft loss to noncompliance. Conclusion. In this series, LTx recipients with HCV infection were able to undergo KTx with a reasonable degree of success. KTx should be offered for end-stage renal failure after LTx, even in the presence of HCV infection, to individuals with stable liver function and no signs of liver failure.

The effects of intraportal prostaglandin E1 administration on hepatic warm ischemia and reperfusion injury in dogs.

To determine the route of prostaglandin E1 (PGE1) administration which would have the greatest protective effect against hepatic warm ischemia, two experiments were performed using dogs. The pharmacokinetics of PGE1 were investigated in a preliminary study, after which, the effects of PGE1 in a 90-min warm ischemic liver model were examined. The dogs were divided into three groups of ten, according to the treatment given: group A was an untreated control group, group B received PGE1 intravenously, and group C received PGE1 intraportally. The PGE1 was infused continuously at a rate of 0.02 μg/kg/min before and after ischemia. All the dogs in groups A and B died within 24 h of induced ischemia. Whereas, six of the ten dogs in group C survived for over 3 days. The arterial ketone body ratio was not maintained in groups A and B, but it was in group C. Furthermore, in group C the serum lipid peroxide level, which reflects hepatocellular membrane damage, was maintained at a lower level than that in the other groups after ischemia. Electron microscopy revealed sinusoid destruction and changes in both the plasma membrane and parenchymal cell mitochondria in groups A and B, while in group C these structures were well preserved. These findings confirmed that intraportally administered PGE1 improved the hepatic microcirculation and stabilized the hepatocellular membranes. Our results indicate that intraportal administration of PGE1 has a greater protective effect than intravenous administration against warm ischemic liver injury.

Warm ischemia and reperfusion injury in diet-induced canine fatty livers.

BACKGROUND Fatty liver is associated with primary nonfunction after liver transplantation, contributing a shortage of suitable liver grafts. Because extensive investigation of mechanisms underlying such nonfunction has been limited largely to rodents, we made a new fatty liver model in dogs and studied primary nonfunction after warm ischemia. METHODS We developed a diet rich in fat but deficient in choline to induce fatty change in canine liver and investigated effects of 60 min of warm ischemia and reperfusion in dogs with such fatty livers. RESULTS Microscopically evident steatosis increased with duration of dietary manipulation (up to 12 weeks), as did hepatic total lipid and triglyceride levels. No dog with >30% of steatotic hepatocytes, >445 mg/g hepatic total lipid or >145 mg/g hepatic triglyceride survived after 60 min of warm ischemia. Arterial ketone body ratios decreased and blood endotoxin increased after reperfusion in nonsurvivors. The main histologic finding in livers of nonsurvivors was marked sinusoidal congestion. CONCLUSIONS Damage to hepatocytes and nonparenchymal cells after warm ischemia and reperfusion was thought to be closely related to sinusoidal microcirculatory disturbances in fatty livers. The canine fatty liver model reported here may be useful in studying the pathology of primary nonfunction and in establishing criteria for allowable degrees of fatty change in potential liver grafts.

Current status of autonomic nerve-preserving surgery for mid and lower rectal cancers: Japanese experience with lateral node dissection.

Surgical practices for treatment of rectal cancer in Japan have changed from extended dissection along perivascular or parietal plane to pelvic autonomic nerve-preserving procedures without compromising radicality of surgical resection. Previous surgical results suggested the significant advantages of extended surgery in survival and local recurrence rate of Dukes B and C patients. More than 15 percent of patients with cancer in the lower rectum have extramesorectal spread to lateral pelvic nodes that can be removed by lateral dissection for local control and cure. Initially the total nerve-preserving procedure has been introduced for a complete preservation of para-aortic and intrapelvic nervous system in patients with early-stage cancer not requiring para-aortic and lateral lymph-node dissection. However, the concept of aggressive surgery for advanced rectal cancer has led to various types of pelvic autonomic nerve-preserving procedures, in which extended lymph-node dissection plus nerve-preserving technique with resection of one or more autonomic nervous segments has been performed. During two decades, total pelvic autonomic nerve-preserving procedure with lateral lymph-node dissection has been used increasingly for Dukes C lesion without increased local recurrence. The overall status of pelvic autonomic nerve-preserving procedures according to clinical experiences in Japan is reviewed in the context of cadaveric anatomic findings, Japanese vs. Western techniques and concepts, and our own clinical data.

Influence of donor condition on postoperative graft survival and function in human liver transplantation.

BODY condition of a brain death patient, such as blood electrolytes and cardiovascular system, is often unstable because of lack of homeostasis, experience of hypoxia, and multiple severe body injuries. Therefore, postoperative hepatic allograft function should be associated with general condition of cadaveric organ donor. For this reason, several retrospective analyses of donor variables have attempted to identify risk factors predictive of both patient and graft survival after liver transplantation. In the present study, we investigated influence of donor condition, including age, need for vasopressor, and serum sodium concentration, on early postoperative graft outcome in human liver transplantation by means of prospective collection of donor and recipient data.