Antithrombin effect on coagulation and fibrinolytic profiles after living donor liver transplantation: a pilot study

Early after liver transplantation, patients are in a hypercoagulable state because of an imbalance between coagulation and fibrinolysis because of the slow recovery of depleted anticoagulant proteins. Antithrombin (AT) is used in anticoagulant protocols to prevent thrombosis. The subjects of the present study were 17 men and eight women that underwent living donor liver transplantation. The initial 15 cases were administered AT concentrate (1500 U/day) on postoperative days (POD) 1 through 3 (AT group) and the following 10 consecutive cases were not administered AT (control). AT, thrombin-AT complex, plasmin-alpha2 plasmin inhibitor complex, thrombomodulin, fibrin degradation product D-dimer (FDP-DD) level, prothrombin time international normalized ratio, activated partial thromboplastin time, and platelet counts were measured. In the AT group, AT activity was maintained at levels >80% for 5 days after transplantation. In the control group, AT activity did not return to normal during the first 2 weeks after the operation. FDP-DD levels were significantly higher in the control group than in the AT group (P < 0.05). Six patients in the control group and three patients in the AT group required transfusions with platelet concentrate (P < 0.05). AT supplementation might reduce FDP-DD levels and prevent decreased platelet counts in the early stages after liver transplantation.

Heparin-induced thrombocytopenia after liver transplantation

BACKGROUND

Unfractionated heparin sodium (UFH) or low-molecular weight heparin (LMWH) is used in anticoagulant protocols at several institutions to prevent thrombosis after liver transplantation. Heparin-induced thrombocytopenia (HIT) is an adverse immune-mediated reaction to heparin, resulting in platelet count decreases of more than 50%. The frequencies of HIT after liver transplantation and platelet factor 4/heparin-reactive antibody (HIT antibody) positivity in liver transplantation patients, however, are unknown.

PATIENTS AND METHODS

The 32 men and 20 women underwent living donor liver transplantation. We started LMWH (25 IU/kg/h) on postoperative day (POD) 1, switching to UFH (5000 U/d) on POD 2 or 3. The dose of UFH was changed according to the activated clotting time level. HIT antibody levels were measured the day before surgery and on POD 7 and 14. Platelet count was measured daily for 3 weeks.

RESULTS

The average platelet counts preoperatively, and on POD 7, 14, and 21 were 65, 88, 149, and 169 x 10(9)/L, respectively. Two patients developed hepatic artery thrombosis on POD 11 and 19, respectively, although they were HIT antibody-negative and their platelet counts were stable. In 2 other patients, the platelet count decreased suddenly from 107 x 10(9)/L on POD 4 to 65 x 10(9)/L on POD 6 and from 76 x 10(9)/L on POD 7 to 33 x 10(9)/L on POD 9, respectively. The heparin-induced platelet aggregation test was negative in these patients. The percentage of HIT antibody-positive patients was 0.5% preoperatively, 5.6% on POD 7, and 5.6% on POD 14. None of the subjects/patients developed UFH-related HIT.

CONCLUSIONS

In our series, the occurrence of HIT after liver transplantation was uncommon.

Impact of live donor age (>or=50) on liver transplantation

BACKGROUND

The question of whether donor age negatively impacts recipient outcome in adult-to-adult living donor liver transplantation (LDLT) is rarely discussed. The aim of this study was to evaluate the impact of older donor age (50 years or older) on recipient outcomes in adult-to-adult LDLT.

METHODS

LDLT data were retrospectively evaluated from our 299 LDLT cases in 297 recipients, which were divided into 2 groups: a younger group (group Y, donor age<50, n=237) and an older group (Group O, donor age>or=50, n=62). Clinical parameters of both recipients and donors were comparable between groups.

RESULTS

There was no difference between the groups in patient survival or postoperative complications of either donors or recipients. In recipients, graft regeneration was significantly impaired in Group O. Graft function, including protein synthesis and cholestasis, was comparable between the 2 groups.

CONCLUSION

Although the regeneration capacity of aged grafts was impaired, the function of grafts from older donors was comparable to that of those from younger donors. There was no difference in the clinical outcomes between the groups.

Impact of celiac axis stenosis on living donor hepatectomy

BACKGROUND

Celiac axis stenosis was once cited as a reason for exclusion from living donor liver transplantation. Donor hepatectomy, however, leaves the pancreaticoduodenal artery arcade untouched, and theoretically, celiac axis stenosis has no impact on otherwise possible donors.

METHODS

Among 350 consecutive adult living donors of liver transplantation at Tokyo University Hospital, we experienced 11 (3%) donors with celiac axis stenosis or occlusion due to the median arcuate ligament.

RESULTS

Harvesting of the right liver was the most common procedure (n = 8), followed by harvesting of segments II and III (n = 2), and left liver (n = 1). The postoperative course was uneventful in all of the donors.

CONCLUSIONS

Our results indicate that donor hepatectomy can be safely performed in the presence of significant celiac artery stenosis.

Renal impairment after living donor liver transplantation

BACKGROUND

There are few reports of postoperative renal impairment after living donor liver transplantation (LDLT).

METHODS

We reviewed 246 LDLT recipients to examine the effects of postoperative renal impairment on the results of LDLT.

RESULTS

The incidence of renal impairment and the requirements for postoperative renal replacement therapy were 29% and 9%, respectively. Intraoperative blood loss (P<.0001) and preoperative serum creatinine (P=.0002) were significant independent risk factors for the development of early renal dysfunction. Patients who required renal replacement therapy had a lower survival rate (P=.01).

CONCLUSIONS

We identified the risk factors for postoperative renal impairment, providing useful metrics to establish a treatment strategy for high risk liver transplant patients.

Relation Between the Middle Hepatic Vein Drainage Area Volume and Alanine Aminotransferease After Left Liver Harvesting

Complete outflow is impossible to maintain on both sides in donors undergoing hemiliver graft harvesting, because the middle hepatic vein (MHV) can be preserved on only one side. The area in which outflow veins are disrupted becomes congested and does not sufficiently regenerate. The relation between changes in alanine aminotransferase (ALT) and the congestive area volume of the congestive area is unknown. The 64 subjects presented herein were living donors who provided the left liver with the caudate lobe and MHV trunk. The midpoint between the tributaries of the MHV and the right hepatic vein was determined preoperatively using computed tomography. The midpoint between the tributaries of the MHV and right hepatic vein and the borderline between the right and left liver were used to predict the MHV drainage area volume. ALT was measured in donors on postoperative days 1, 3, 5, 7, 10, and 14. The patients were divided into three groups according to the ratio of calculated MHV drainage area volume in the remnant right liver: less than 15% (n = 21, group A); greater than 15% and less than 20% (n = 18, group B); greater than 20% (n = 25, group C). There were significant differences in the ALT levels between groups (P = .004). MHV drainage area volume, calculated using the present method, was associated with high ALT levels after left liver harvesting with the MHV. The present study suggests that persistently high ALT levels are associated with the volume of the interrupted MHV drainage area.

Simultaneous hepatic artery and portal vein thrombosis after living donor liver transplantation

Simultaneous hepatic artery and portal vein thrombosis rarely occurs after liver transplantation. The etiology is unknown. Of 213 patients (72 children and 141 adults) that underwent living donor liver transplantation (LDLT) from January 1996 to March 2003, 4 (2%) developed simultaneous thrombosis at 3 hours to 7 days (median, 4 days) after the operation. Emergent thrombectomy was performed in three patients; the remaining patient was registered in the Japan organ transplant network. All of the patients died due to hepatic failure (range, 18 hours to 6 days after the diagnosis; median, 2 days). Portal vein, hepatic artery, and hepatic vein velocity in the liver graft were measured every 12 hours by Doppler ultrasonography for 2 weeks after liver transplantation. These parameters were stable until just before the simultaneous thrombosis. These findings indicate that protocol Doppler ultrasonography can diagnose, but not predict, this fatal complication.