Effects of a Domino Liver Transplantation Program on Patient Survival and Waiting List Time: A Single-Center Retrospective Study

Explanted livers from patients with familial amyloid polyneuropathy have often been used for domino liver transplantation (DLT). This has expanded the organ pool for liver transplantation. We evaluated the effects of a single-center DLT program on waiting list duration and patient survival. Liver transplants conducted from 2007 to 2017 were analyzed. Selected patients, all liver transplant candidates above the age of 60 years and patients with hepatocellular carcinoma, were offered DLT. Survival, time on waiting list, and operative factors were evaluated. The study group included 485 patients transplanted with grafts from deceased donors (conventional liver transplantation) and 149 patients who were offered and accepted a potential DLT, of whom 34 underwent DLT and 115 did not; these patients received a deceased donor graft (non-DLT). Five-year and overall estimated survival rates respectively were 79% and 54.4% for DLT and 67.6% and 46.7% for non-DLT (P = .67, log rank test). No differences were noted in survival (P = .816) or waiting times (P = 1.0) between DLT and non-DLT groups. As expected, survival time in the conventional liver transplantation group was longer (84.7% and 60.6%, P < .001). Donor age and ischemia time were significantly different between DLT and non-DLT (P < .001). DLT has enabled 6% additional transplantations without affecting waiting time or survival (34/600).

The determinants and significance of intraluminal stent protrusion in patients with acute myocardial infarction

Background

The mchanisms leading to intraluminal stent protrusion in patients following primary coronary angioplasty for ST-elevation myocardial infarction (STEMI) are not fully elucidated.

Purpose

We sought to investigate composition of stent protrusion, its systemic and local determinants as well as its consequences for epicardial blood flow restoration in STEMI patients.

Methods

We enrolled 85 STEMI patients with median age 61 (interquartile range 54–69) years. In all patients optical coherence tomography of an infarct-related artery was performed first following epicardial blood flow restoration after aspiration thrombectomy and second after final stent deployment. On admission, besides standard laboratory investigations we measured calibrated automated thrombogram parameters including time to start clotting, time to peak thrombin generation, peak thrombin generation and endogenous thrombin potential as well as ex vivo measured fibrin clot permeability reflecting fibrin pore size and fibrin clot lysis time.

Results

A median volume of stent protrusion was 13.4 (8.5–25.4) mm3 while atherothrombotic burden defined as a ratio of free intraluminal thrombus and tissue protrusion divided by stent volume was 6 (3.9–7.5)%. The main component of stent protrusion was lipid tissue in 32 (37.6%), fibrous tissue in 27 (31.8%) and thrombus in 26 (30.6%) patients. A volume of stent protrusion was correlated with total stent volume (R=0.79, P&lt;0.001) and the length of lipid reach pool in the naïve coronary vessel intima (R=0.31, P=0.007) whereas atherothrombotic burden was correlated with residual thrombus volume before stent implantation (R=0.34, P=0.003), arcus of maximal lipid reach pool in the naïve coronary vessel intima (R=0.25, P=0.03) and stent area (R=0.26, P=0.02). The residual thrombus volume after aspiration thrombectomy was correlated with clot permeability (R=0.024, P=0.04) and inversely correlated with time to peak thrombin generation (R=−0.23, P=0.04). A temporary deterioration of epicardial blood flow of at least 1 point in Thrombolysis in Myocardial Infarction scale following stent implantation detected in 20 (23.5%) patients was associated with shorter lag time (3.0 [2.7–3.3] vs. 3.3 [3.0–4.0] min, P=0.015), shorter time to peak thrombin generation (5.7 [5.3–6.1] vs. 6.3 [5.7–7.1] min, P=0.026) and more frequent presence of lipid-rich stent protrusion (65 vs. 29%, P=0.007) as compared to the patients without slow-flow phenomenon after stent deployment.

Conclusions

The total volume of stent protrusion is correlated with local determinants including stent size and lipid content in the naïve coronary artery intima. After adjustment for stent volume, atherothrombotic burden is additionaly affected by residual thrombus volume after aspiration thrombectomy. However, patients with faster thrombin formation and lipid-rich stent protrusion are more prone to slow-flow phenomenon following stent implantation.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Science Center of Poland

Liver Transplantation for Acute Intermittent Porphyria

Recurrent attacks of acute intermittent porphyria (AIP) result in poor quality of life and significant risks of morbidity and mortality. Liver transplantation (LT) offers a cure, but published data on outcomes after LT are limited. We assessed the pretransplant characteristics, complications, and outcomes for patients with AIP who received a transplant. Data were collected retrospectively from the European Liver Transplant Registry and from questionnaires sent to identified transplant and porphyria centers. We studied 38 patients who received transplants in 12 countries from 2002 to 2019. Median age at LT was 37 years (range, 18-58), and 34 (89%) of the patients were women. A total of 9 patients died during follow-up, and 2 patients were retransplanted. The 1-year and 5-year overall survival rates were 92% and 82%, which are comparable with other metabolic diseases transplanted during the same period. Advanced pretransplant neurological impairment was associated with increased mortality. The 5-year survival rate was 94% among 19 patients with moderate or no neuropathy at LT and 83% among 10 patients with severe neuropathy (P = 0.04). Pretransplant renal impairment was common. A total of 19 (51%) patients had a GFR < 60 mL/minute. Although few patients improved their renal function after LT, neurological impairments improved, and no worsening of neurological symptoms was recorded. No patient had AIP attacks after LT, except for a patient who received an auxiliary graft. LT is a curative treatment option for patients with recurrent attacks of AIP. Severe neuropathy and impaired renal function are common and increase the risk for poor outcomes. If other treatment options fail, an evaluation for LT should be performed early.

Intrahepatic Microdialysis for Monitoring of Metabolic Markers to Detect Rejection Early After Liver Transplantation

OBJECTIVES

The clinical and biochemical manifestations of acute rejection after liver transplantation are nonspecific, and a liver biopsy is often needed to verify the diagnosis. This may delay treatment. The aim of this study was to evaluate whether monitoring of intrahepatic glucose, lactate, pyruvate, and glycerol by microdialysis can be used to predict rejection early after liver transplantation.

METHODS

Seventy-one patients undergoing liver transplantation were included in the study. The patients were monitored using microdialysis for up to 6 days postoperatively. Patients who developed acute rejection within 1 month were identified according to standard protocol. Area under the curve (AUC) was calculated for 12-hour intervals for glucose, lactate, pyruvate, glycerol, and lactate/pyruvate ratio. Patients with and without rejection were compared with respect to these parameters, as well as standard liver blood investigations and time-zero biopsies.

RESULTS

The lactate/pyruvate ratio was higher at 0 to 12 hours in the group with rejection as compared to the group without rejection. Glucose was lower in the group with rejection at 24 to 48 hours. Also, the intrahepatic lactate levels at 48 to 72 hours and pyruvate levels at 60 to 72 hours after liver transplantation, were higher in the rejection group. The lactate/pyruvate ratio at 0 to 12 hours and lactate at 60 to 72 hours were two independent risk factors for rejection within the first month after liver transplantation. No significant differences in glycerol levels could be detected between the two patient groups.

CONCLUSIONS

Microdialysis monitoring following liver transplantation may be useful in the detection of the metabolic events that precede rejection. The metabolic patterns detected by microdialysis early after transplantation indicate a possible relation between primary ischemia-reperfusion injury and the development of rejection. Identifying these patterns may help to identify patients at risk for the development of acute rejection and may help select those who may benefit from higher dose of immunosuppression early after liver transplantation.

Association of post-reperfusion syndrome and ischemia-reperfusion injury with acute kidney injury after liver transplantation

BACKGROUND

Acute kidney injury (AKI) is frequently observed after orthotopic liver transplantation (OLT) even in patients with previously normal renal function. In this study, we investigated the impact of factors such graft steatosis, post-reperfusion syndrome (PRS), and hepatic ischemia reperfusion injury (HIRI) on the development of AKI after OLT in adult patients.

METHODS

We retrospectively examined consecutive adult patients who underwent OLT at our institution between July 2011 and June 2017. AKI was diagnosed based on the criteria proposed by the International Kidney Disease Improving Global Outcomes (KDIGO) workgroup. Peak aspartate aminotransferase (AST) level within 72 hours after OLT was used as a surrogate marker for HIRI. Graft steatosis was diagnosed by histopathological examination using specimens biopsied intraoperatively at the end of transplantation procedure and categorized as <10%, 10%-20%, 20%-30%, and ≥30% of hepatic steatosis.

RESULTS

Out of 386 patients, 141 (37%) developed AKI (KDIGO stage 1:71 patients; stage 2:29 patients; stage 3:41 patients). Multivariable logistic regression analysis revealed that cold ischemic time (P = .012) and HIRI (P = .007) were independent risk factors for post-OLT AKI. Multivariable analysis also revealed that graft steatosis was associated with HIRI but not directly with AKI. PRS was not associated with HIRI or AKI in the multivariable analyses.

CONCLUSION

Our results indicate that greater severity of liver graft injury during transplantation negatively affects renal function after OLT. As expected, the severity of liver graft steatosis contributes to accelerated liver injury occurring during the transplantation procedure.

Regulation of bile acid metabolism in biliary atresia: reduction of FGF19 by Kasai portoenterostomy and possible relation to early outcome

BACKGROUND

Fibroblast growth factor 19 (FGF19) is produced in the small intestine and is involved in suppression of hepatic bile acid (BA) synthesis. FGF19 is also expressed in the liver and serum levels are elevated in adults with cholestatic liver disease. This may reflect a rescue mechanism to dampen liver injury caused by increased intrahepatic BAs.

OBJECTIVES

To examine circulating FGF19 at early stages of biliary atresia and at short-term follow-up post-Kasai portoenterostomy (KPE) in relation to noncholestatic infants. The relationship between FGF19, BAs and markers for BA synthesis and hepatic gene expression of factors involved in BA metabolism were also evaluated.

METHODS

Liver tissue, portal and peripheral blood samples were obtained from fifteen patients at KPE; additional blood was collected 4-6 months after surgery. Two control groups were included; to examine possible changes related to surgery and to compare FGF19 in biliary atresia to noncholestatic infants.

RESULTS

Circulating FGF19 levels correlated to its hepatic gene expression at time of KPE in biliary atresia and levels were elevated compared to noncholestatic infants. At follow-up, FGF19 levels were markedly reduced, and the decline coincided with reductions in bilirubin and conjugated chenodeoxycholic acid and with increased levels of the BA synthesis marker C4.

CONCLUSION

Elevated circulating FGF19 in biliary atresia is of hepatic origin and reduced following KPE. Changes in serum FGF19 may reflect the level of restoration of the enterohepatic circulation, and this warrants further long-term studies on the role of FGF19 in the cholestatic liver.

Gas Chromatographic Determination of Deoxynivalenol in Wheat with Electron Capture Detection: Collaborative Study

Ten laboratories participated in a collaborative study of a method for the determination of deoxynivalenol in wheat by gas chromatography with electron capture detection. Each laboratory analyzed 6 samples in duplicate. Each collaborator received samples spiked at the 100.3, 501.3, and 1002.6 ng/g levels; a control sample; and 2 naturally contaminated samples. The average recovery (outliers excluded) for the spiked samples was 92.2%. The mean repeatability and reproducibility, respectively, were 32.2 and 41.3% for the spiked samples and 30.9 and 47.6% for the naturally contaminated samples. The method was adopted official first action.

Transfer of Hemolysis, Elevated Liver Enzymes, and Low Platelets Syndrome by a Liver Graft From a Pregnant Female Donor to a Male Recipient: A Case Report

Eclampsia with hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome is a rare complication of pregnancy. HELLP syndrome may occur up to a week postpartum in women with eclampsia. CASE REPORT: We report a case of liver transplantation with the organ procured from a pregnant (gestation week 28) female donor who suffered brain death after cerebellar hemorrhage owing to eclampsia. Liver function tests were normal at the time of liver procurement. The liver graft was matched to a 62-year-old man with primary sclerosing cholangitis. On day 7 after an uneventful transplantation, the recipient presented with increased aminotransferases and severe thrombocytopenia. The recipient also developed hypertension and hyperthermia and a clinical picture of HELLP syndrome. The patient underwent emergency liver retransplantation on day 12 after the first transplantation. Intraoperatively, massive necrosis of the liver graft with diffuse subcapsular hematomas was seen. CONCLUSIONS: It appears that in our case, HELLP syndrome was transferred to and occurred in a male recipient. Eclampsia in the donor without overt HELLP syndrome may persist and be transferred by liver graft, developing into HELLP syndrome even in a male recipient. Therefore, liver grafts from female donors with eclampsia should be used with caution. Emergency retransplantation may be necessary.

A giant exoplanet orbiting a very-low-mass star challenges planet formation models

Surveys have shown that super-Earth and Neptune-mass exoplanets are more frequent than gas giants around low-mass stars, as predicted by the core accretion theory of planet formation. We report the discovery of a giant planet around the very-low-mass star GJ 3512, as determined by optical and near-infrared radial-velocity observations. The planet has a minimum mass of 0.46 Jupiter masses, very high for such a small host star, and an eccentric 204-day orbit. Dynamical models show that the high eccentricity is most likely due to planet-planet interactions. We use simulations to demonstrate that the GJ 3512 planetary system challenges generally accepted formation theories, and that it puts constraints on the planet accretion and migration rates. Disk instabilities may be more efficient in forming planets than previously thought.

Characteristics and risk factors for recurrence of nonalcoholic steatohepatitis following liver transplantation

OBJECTIVES

Nonalcoholic steatohepatitis (NASH), which is a common and increasing indication for liver transplantation (LT), is known to recur after LT. Since the recurrence of NASH can lead to graft failure, the identification of predictive factors is needed and preventive strategies should be implemented.

METHODS

We retrospectively examined 95 patients who had undergone LT for NASH or alcoholic liver disease (ALD) as a primary indication. We evaluated peritransplant characteristics and histological findings 1-year post LT among liver transplant patients due to NASH or ALD.

RESULTS

Pre-LT body mass index (BMI) was higher and pre-LT diabetes was more prevalent in NASH patients than in ALD patients (p < .01). The difference of BMI persisted at 3 months and 1 year after LT. There were no differences between the groups regarding histopathological findings including the degree of steatosis and fibrosis in 1-year biopsy. In multivariate analysis, recipient age and 1-year BMI were independent risk factors for post-LT fatty liver disease development. Regarding predictive factors of NASH recurrence, the prevalence of pre-LT insulin-dependent diabetes was significantly higher in patients who developed NASH recurrence than those who did not. The increase of HbA1c at 1-year post-LT checkup was higher in patients who developed recurrence than those who did not, although the difference did not reach statistical significance.

CONCLUSIONS

The results of this study suggest that insulin-dependent diabetes has detrimental effects on NASH recurrence following LT. Optimal glycemic control should be recommended, but studies are needed to prove its preventive effect on NASH recurrence.

Pharmacokinetics and Anticoagulant Effect of Hirudin in Man

The pharmacokinetics and the effects on the haemostatic system of hirudin were assessed in six healthy subjects after single intravenous or subcutaneous dose (1000 AT-U/kg). When hirudin was given intravenously first-order elimination kinetics followed the initial distribution phase. The decline in plasma hirudin concentration was most adequately expressed by a biexponential equation describing a two compartment model. A mean elimination half-life of 0.84 hr and a mean volume of distribution of 12.9 1 were calculated. After subcutaneous injection a low hirudin level (∼0.5 AT-U/ml) was maintained for a prolonged period of time.

In the 24 hour-urine up to 50 per cent of the administered amount of hirudin was excreted in active form.

Thrombin time, partial thromboplastin time and prothrombin time measured in plasma samples ex vivo were prolonged dependent on the hirudin plasma level. Platelet counts, fibrinogen level and the fibrinolytic system were unchanged. Bleeding time was prolonged twice at maximum.

Subcutaneous or intravenous administration of pure hirudin was tolerated without side-effects.

Influence of Cyproheptadine on Endotoxin-Induced Disseminated Intravascular Coagulation (DIC) in Weaned Pigs

Changes in the coagulation system typical of consumption reaction, microthrombosis in the lungs and other organs and haemodynamic disturbances caused by infusion of endotoxin in weaned pigs were prevented by treatment with the serotonin receptor antagonist cyproheptadine.

Comparative Studies on Thrombin Inhibitors in Experimental Microthrombosis

The influence of thrombin inhibitors, which differ both in their chemical structure and type of inhibition on thrombin-induced microthrombosis was studied in rat lungs. The antithrombotically effective doses and blood levels of the compounds correlated with their kinetic constants for inhibition of thrombin. In preventing microthrombosis, some of the synthetic inhibitors tested surpassed the effectiveness of heparin and approached that of the naturally occurring inhibitor hirudin.

Pharmacological Studies on the Antithrombotic Action of Hirudin in Experimental Animals

The pharmacodynamics and pharmacokinetics of hirudin were studied in dogs, rabbits and rats. Hirudin proved to be a well tolerated substance with low toxicity. After intravenous injection it was eliminated with a half time of 50 to 60 min. It was nearly completely excreted through the kidneys in biologically active form. The efficacy of hirudin in preventing venous thrombosis, vascular shunt occlusion and disseminated intravascular coagulation in rats was demonstrated.

Anticoagulant and Antithrombotic Action of Novel Specific Inhibitors of Thrombin

A series of new specific inhibitors of thrombin, cyclic amides of Nα-arylsulfonyl-amidinophenylalanine, was studied for anticoagulant action in vitro and in vivo. The inhibitors showed strong anticoagulant effects in vitro. The time course of the anticoagulant effect of the inhibitors in rabbits and rats was monitored using plasma thrombin time determinations. In rats, the inhibitors prevented the formation of experimental venous thrombi and of thrombin-induced microthrombosis. The new derivatives of benz-amidine presented may be useful as immediately acting anticoagulants.

Studies in Experimental Animals on Disseminated Intravascular Coagulation (DIC)

Changes in the clotting system, as well as morphological and functional alterations corresponding to that of the pathologic phenomenon of disseminated intravascular coagulation (DIC) or consumption coagulopathy, were produced by thrombin infusion (550 NIH U × kg−1 × h−1) in rats and simultaneous inhibition of fibrinolysis by PAMBA (100 mg/kg).

Changes in the fibrinogen level and platelet count as well as the appearance of fibrin monomers and the formation of microthrombi in several organs were evaluated. Simultaneously, the function of the respiratory system was investigated by continuous measurement of oxygen consumption as well as elasticity and water content of the lung. From the time course of the alterations in the several parameters, conclusions can be drawn for the pathogenesis and the possible therapeutic influence on DIC.

Comparison of the Anticoagulant and Antithrombotic Effects of Synthetic Thrombin and Factor Xa Inhibitors

The anticoagulant effect of selected synthetic inhibitors of thrombin and factor Xa was studied in vitro in commonly used clotting assays. The concentrations of the compounds doubling the clotting time in the various assays were mainly dependent on their thrombin inhibitory activity. Factor Xa inhibitors were somewhat more effective in prolonging the prothrombin time compared to the activated partial thromboplastin time, whereas the opposite was true of thrombin inhibitors.

In vivo, in a venous stasis thrombosis model and a thromboplastin-induced microthrombosis model in rats the thrombin inhibitors were effective antithrombotically whereas factor Xa inhibitors of numerically similar IQ value for the respective enzyme were not effective at equimolar dosage

The results are discussed in the light of the different prelequisiles and conditions for inhibition of thrombin and factor Xa in the course of blood clotting.

Antithrombin- und Antiplasminwirkung von 4-Amidinophenylbrenztraubensäure (APPA) in vivo

Es wurde die Antithrombin- und Antiplasmin Wirkung der 4-Amidinophenylbrenztraubensäure (APPA) an Kaninchen untersucht. Dabei hat sich gezeigt, daß die in biochemischen Untersuchungen als kompetitiver Hemmstoff der Gerinnungsfermente wirkende Verbindung auch in vivo antikoagulierende und antifibrinolytische Wirkungen entfaltet, die sich sowohl nach intravenöser als auch nach oraler Gabe des Inhibitors messend verfolgen lassen.

Die Wirkung von Thrombininfusionen oder Streptokinaseinfusionen wurde bei Gegenwart des Inhibitors im Blut unterbunden.

Die Resorptionsquote der APPA nach oraler Applikation beträgt 45% und die Halbwertzeit 100 min. Ein Teil der applizierten Inhibitormenge wird in unveränderter Form mit dem Urin ausgeschieden.

APPA stellt ein pharmakologisches Modell für eine neue Klasse von Stoffen zur medikamentösen Beeinflussung der Blutgerinnungs- und Fibrinolyse Vorgänge dar.

Pharmakokinetik von Hirudin bei gestörter Nierenfunktion

Die Pharmakokinetik von r-Hirudin wurde bei 9 Patienten mit verschiedenen Stadien einer chronischen Niereninsuffizienz untersucht. Rekombinantes Hirudin wurde einmalig intravenös in einer Dosierung von 0,1 mg/kg verabreicht, und es wurden die Eliminationshalbwertszeit, die kumulative Hirudinexkretion im Urin sowie Gerinnungsglobaltests und die Blutungszeit bestimmt.

Bei gesunden Probanden betrug die Eliminationshalbwertszeit 0,9 ±0,2 h. Innerhalb von 48 Stunden wurden 38 ± 10% der applizierten Hirudindosis in unveränderter Form im Urin ausgeschieden, hauptsächlich während der ersten Stunde. Bei sieben Patienten mit chronischer Niereninsuffizienz lag die Eliminationshalbwertszeit zwischen 15 und 41 Stunden. Während bei drei dieser Patienten die kumulative Hirudinausscheidung im Urin auf 70-80% der injizierten Dosis erhöht war, betrug sie bei den vier anderen Patienten 39 ± 8%, jedoch zeitlich deutlich verzögert. Bei den zwei bilateral nephrektomierten Patienten wurde eine Eliminationshalbwertszeit von 141 ± 14 h ermittelt. Die renalen Clearancewerte von Kreatinin und Hirudin korrelieren linear miteinander mit einem Koeffizienten von 0,872. Bei allen untersuchten Patienten waren die aktivierte partielle Thromboplastinzeit und die Blutungszeit nur geringgradig verlängert.

Diese Ergebnisse bestätigen die tierexperimentellen Befunde, daß Hirudin nicht extrarenal metabolisiert bzw. eliminiert wird. Aus den Untersuchungen ist zu folgern, daß die bei eingeschränkter Nierenfunktion veränderte Pharmakokinetik von Hirudin eine individuell angepaßte, verminderte Dosierung erfordert.

Albumin mass balance and kinetics in liver transplantation

Background

In major abdominal surgery albumin is shifted from the circulation, presumably leaking into the interstitial space, contributing to a 30–40% decrease in plasma albumin concentration. During and after liver transplantation exogenous albumin is infused for volume substitution and to maintain plasma albumin concentration. Here we used liver transplantation as a model procedure for the study of albumin mass balance and kinetics during major abdominal surgery with albumin substitution.

Methods

Patients were studied during liver transplantation (n = 16), and until postoperative day 3 (POD 3) (n = 11). Cumulative perioperative albumin shift was assessed by mass balance of albumin and hemoglobin. Synthesis rates of albumin and fibrinogen were estimated by the flooding technique using deuterium-labeled phenylalanine. Albumin distribution was assessed by radioiodinated human serum albumin.

Results

At the end of surgery, 37 ± 17 g of albumin (p < 0.0001) had shifted from plasma, and this amount was stable until POD 3 (48 ± 33 g, p = 0.0017 versus baseline). There was 91 ± 37 g exogenous albumin infused peroperatively and another 47 ± 35 g was infused postoperatively until POD 3. Absolute synthesis rates of albumin and fibrinogen on POD 3 were 239 ± 84 mg/kg body weight/day and 33 mg/kg body weight/day (range 5–161), respectively.

Conclusions

Albumin net leakage from plasma progressed until the end of surgery, and was then unaltered until POD 3. This is in contrast with the normalization of the cumulative albumin shift identified at day 3 after non-transplant major abdominal surgery. Liver synthesis of export proteins was high compared to reference values at the third postoperative day, suggesting rapid recovery of synthesis capacity.

Trial registration

Swedish Medical Product Agency, EudraCT 2015-002568-18. Registered on 15 July 2015.