Albrecht Bornscheuer

HTK-solution (Bretschneider) for human liver transplantation. First clinical experiences.

ZusammenfassungDie kardioplegische Lösung HTK nach Bretschneider ist bisher noch nicht im Bereich der klinischen Lebertransplantation verwendet worden. Hier werden die ersten Ergebnisse von 14 Patienten vorgestellt, denen eine mit HTK-Lösung protektionierte Leber transplantiert wurde. Die Eignung der HTK-Lösung konnte gezeigt werden. Alle Transplantate zeigten eine Primärfunktion mit Ausnahme eines Transplantates, bei dem die initiale Nichtfunktion zweifelsfrei spenderbedingt war. Die höchsten friihpostoperativen Werte der Transaminasen, die als Zeichen des Ischämieschadens herangezogen wurden, waren durchschnittlich und vergleichbar mit den Transaminasenausschüttungen nach anderen Lösungen. Unter Verwendung der HTK-Lösung konnte eine Primarfunktion selbst bei solchen Transplantaten erzielt werden, die prospektiv als solche von problematischer oder geringer Qualität eingeschätzt worden waren, and Lebern mit schlechten Funktionstesten (MegX) funktionierten von Beginn an. Deshalb scheint die HTK-L6sung die Ausweitung der Akzeptanzkriterien für Spenderlebern zu ermöglichen. Es war nicht das Ziel dieser Studie, die kalte Ischämiezeit zu verlängern, aber drei Transplantate mit 11 h and 12 h 25 min nahmen unmittelbar nach Reperfusion ihre Funktion auf. Wie weft die kalte Ischämiezeit ausgedehnt werden kann, ist noch eine offene Frage. Alle Spenderlebern wurden aufgrund der geringen Viskosität der HTK-Lösung schlagartig gekühlt und homogen perfundiert. Alle Lebern hatten eine weiche Konsistenz nach der Perfusion, was kein oder nur ein geringes Zellödem bedeutet. Aus diesen Gründen ist HTK eine effektive Lösung für die Leberkonservierung.SummaryThe cardioplegic HTK-solution (Bretschneider) has not been used in human liver transplantation as yet. Herein the first results obtained from 14 patients with HTK-preserved liver grafts are presented. The suitability of HTK-solution could be shown. All grafts functioned primarily except one, where initial non-function was obviously due to donor reasons. The early postoperative peak values of transaminases as a sign of ischemic damage were average and similar to the values of other flushout solutions. Using HTK primary function could be achieved even in livers prospectively assessed as only of fair quality, and livers with poor donor function tests (MegX) functioned from the beginning. HTK-solution therefore seems to allow widening of the acceptance criteria for donor livers. It was not the aim of this trial to extend cold ischemic time, but 3 livers with 11 h and 12 h 25 showed immediate function. How far cold ischemic time can be extended is a still open question. All livers were rapidly cooled and homogeneously flushed out due to the low viscosity of HTK-solution. All livers had a soft consistency after perfusion indicating a low degree of cell edema. HTK therefore is an effective solution for liver preservation.

Ex-vivo resection techniques in tissue-preserving surgery for liver malignancies

Abstract Some primary and secondary liver tumours are not absolutely irresectable, but cannot be resected using a conventional approach because of the limited warm ischaemia tolerance of the liver or poor accessibility of the tumour region. In such situations, the techniques of ex vivo liver surgery, pioneered by Rudolf Pichlmayr some 10 years ago, offer new chances for R0 resection. All the three different approaches, namely ”in situ”-, ”ante situm”-, and ”ex situ” resection, require the use of measures originally developed for transplantation, such as hypothermic liver perfusion and veno-venous bypass. They differ mainly in the extent to which major vessels are divided in order to achieve optimal mobility of the organ. The results show that radical resection can be achieved accomplished in many cases. If necessary, complex vascular reconstructions can be performed. Although perioperative morbidity and mortality are high, there are a number of long-term survivors. Tumour recurrence, however, remains the main problem over the long term. In conclusion, ex vivo liver surgery is an important extension of surgical treatment possibilities. However, the procedure is suitable only for a small number of carefully selected patients and should be reserved for use in specialised centres. Furthermore, in view of the fact that the results are not yet optimal, additive and adjuvant treatment modalities are needed.

Tissue oxygen saturation of human hepatic grafts after reperfusion: paradoxical elevation in poor graft function

The present study investigated the pathophysiology of primary nonfunction (PNF) of grafted livers with regard to hepatic tissue oxygenation. Hemoglobin oxygen saturation in hepatic tissue (H−So2) after reperfusion was determined using near-infrared spectroscopy. Graft tissue oxygen consumption was also estimated according to Ficks principle. Six grafts with PNF were compared with 40 functioning grafts. One PNF graft with extremely low and heterogenous H−So2 after reperfusion was found to contain multiple intrahepatic portal thrombi. However, five other PNF grafts showed no lower and, on the contrary, more homogeneous H−So2 at the end of the operation. As a whole, mean H−So2 was negatively correlated and the coefficient of variation (CV) of H−So2 was positively correlated with graft tissue oxygen consumption at the end of the operation; grafts whose H−So2 showed a secondary decrease had better initial function. In later relaparotomy, the H−So2 of the five PNF grafts was significantly higher and more homogeneous than that of the functioning grafts. These results suggest that the H−So2 level reflects tissue oxygen consumption as well as oxygenation, and that the dissociation of both factors can occur in hepatic graft reperfusion. Not only low and heterogeneous H−So2 but also high and homogenous H−So2, suggesting some shunt mechanism, can be signs of poor graft function.

The course of untreated acute rejection and effect of repeated anti-CD3 monoclonal antibody treatment in rhesus monkey liver transplantation.

The effect of single and repeated treatment of liver allograft rejection using an anti-CD3 monoclonal antibody (FN 18) was studied in a rhesus monkey model. Eight RhLA-mismatched monkeys received initial postoperative immunosuppression with CsA/prednisolone for 28 days. After cessation, acute rejection occurred in all animals (days 28–50). Control animals (n = 3) receiving no rejection treatment developed a chronic progressive rejection and died at days 112–160. In the animals treated with FN 18 (n = 5), the first acute rejection was successfully reversed. T lymphocytes were cleared from the peripheral blood and the graft. Increased class I and class II MHC-antigens on hepatocytes were reduced to normal levels within 5 days of treatment. The second rejection treatment remained ineffective in two animals with antiidiotypic antibodies to FN 18 but was successful in two animals with a low antimouse response. These four animals survived 1 GO-SOS days. The results have a number of implications regarding the course of untreated rejection in human liver transplant recipients and repetitive rejection treatment with monoclonal antibodies.

Reduced P-selectin expression on circulating platelets after prolonged cold preservation in renal transplantation

Abstract: The uremic state in patients with terminal renal insufficiency is accompanied by a bleeding tendency connected with platelet dysfunction. Prolonged cold ischemia and inflammatory interactions between leukocytes, platelets and endothelial cells contribute to ischemia‐/reperfusion (I/R) injury and may impair long‐term graft survival. We evaluated the influence of the duration of cold preservation time on the expression of platelet GPIIb/IIIa and P‐selectin and on the formation of leukocyte‐platelet complexes after kidney transplantation. Fourteen patients undergoing kidney transplantation were divided into group I with long preservation time (26.6 ± 1.9 h) and group II with short preservation time (8 ± 6.1 h). Five venous blood samples (3 ml) were taken before induction of anesthesia, 12 h, 2, 7 and 14 d after transplantation. Surface expression of the GPIIb/IIIa, P‐selectin and the percentage of platelet‐granulocyte complexes were quantified by flow cytometry. Additionally blood from seven healthy volunteers was analyzed. GPIIb/IIIa and P‐selectin expression on circulating platelets were significantly decreased in the long and the short‐term graft preservation group compared with healthy volunteers. A significantly reduced P‐selectin expression was found in the long‐term preservation group compared with the short‐term group. The percentage of platelet‐granulocyte complexes also decreased in both preservation groups in the first 2 d after reperfusion and remained in this state in the long‐term preservation group. Reduced expression of P‐selectin on circulating platelets may be an indicator of I/R injury after prolonged kidney graft preservation.

In-situ, ante-situm, and ex-situ surgical approaches for otherwise irresectable hepatic tumors

SummaryBackground: Primary liver tumors or liver metastases may be either irresectable, or only resectable at high risk because of their local relation to important vascular structures (hilum of liver, venous confluens, V. cava).Methods: Technically advanced methods of liver resection based on hypothermic perfusion are described, analyzed, and discussed.Results: The techniques of ex-situ, ante-situm, or in-situ liver surgery under hypothermic perfusion permit resection under complete vascular occlusion without considerable time limitations, and with optimized exposition. If required, extended vascular reconstructions may be performed. The results, however, show that these techniques of resection are associated with a relevant morbidity and mortality, although radical resection can be achieved in many instances. Good results can be obtained with increasing experience and optimized indications in selected cases.Conclusions: These advanced approaches to liver resection have enriched the surgical armament and can be useful in defined situations.ZusammenfassungGrundlagen: Primäre Lebertumoren oder Lebermetastasen können aufgrund ihrer Lagebeziehung zu kritischen Gefäßstrukturen (Leberhilus, venöser Konfluens oder V. cava) nicht oder nur mit hohem operativem Risiko resezierbar sein.Methodik: Technisch fortgeschrittene Methoden der Leberresektion unter hypothermer Perfusion werden vorgestellt, analysiert und diskutiert.Ergebnisse: Die Techniken der Leberresektion unter hypothermer Perfusion ex situ, ante situm oder in situ erlauben eine Resektion unter komplett ischämischen Bedingungen, ohne relevante Zeitlimitierung und mit optimaler Exposition. Falls erforderlich, können auch komplexe Gefäßrekonstruktionen durchgeführt werden. Die Ergebnisse zeigen, daß diese Verfahren der Resektion mit einer relevanten Morbidität und Mortalität verbunden sind, in vielen Fällen jedoch eine radikale Resektion erreicht werden kann. Mit zunehmender Erfahrung und optimierter Indikationsstellung können in ausgewählten Fällen gute Ergebnisse erzielt werden.Schlußfolgerungen: Insgesamt erweitern diese fortgeschrittenen Verfahren der Leberresektion das Rüstzeug des Chirurgen und können bei bestimmten Indikationen sinnvoll sein.

Renal Transplantation Normalized Hydrogen Peroxide Production of Neutrophils within the First Day

Background: Hemodialysis patients are in a state of oxidant stress. In renal transplantation reactive oxygen species (ROS) are considered to be important factors of ischemia-reperfusion injury. Neutrophils produce ROS as part of the host defense against invading bacteria. This study was designed to investigate whether neutrophil function in hemodialysis patients is immediately affected by renal transplantation. Methods: We evaluated the neutrophil respiratory burst and phagocytic activity in renal transplant patients with living-related donor (LRD) and cadaveric donor (CAD) grafts using flow cytometry techniques. Twenty patients (LRD = 6, CAD = 14) and 20 healthy volunteers were included in the study. Venous blood samples were drawn before anesthesia, 5 min before reperfusion, 1 h and 1, 3 and 7 days after reperfusion. Results: Before surgery, a significant increase in hydrogen peroxide production in neutrophils was seen for both renal transplantation groups compared to healthy subjects. Within 24 h after reperfusion hydrogen peroxide production almost decreased to normal values. The phagocytic capacity of neutrophils was continuously depressed. There were no differences between the CAD and LRD groups. Conclusions: We found that the enhanced respiratory burst activity of patients with chronic renal failure decreased to normal values within 1 day following renal transplantation. Our results suggest that reduced respiratory burst activity resulting in a diminished risk of tissue damage by the uncontrolled production of ROS.

Potential various appearances of hyperacute rejection in human liver transplantation

ZusammenfassungBei 2 von 81 Lebertransplantationen wurde ein Transplantatversagen beobachtet, das auf eine hyperakute Abstoßung zurückgeführt wurde. Bei der ersten Patientin, die in einer schwierigen, 19 Einheiten Blut und Plasma erfordernden Operation transplantiert wurde, zeigte sich zunächst eine gute Sofortfunktion des Transplantates, bis es am Tag 1–2 zu einem plötzlichen Funktionsverlust kam. Das Cross-match war positiv. Der zweite Patient erhielt ein drittes Transplantat, nachdem das erste eine spenderbedingte Nichtfunktion aufgewiesen hatte und das zweite, blutgruppeninkompatible Organ abgestoßen worden war. Das dritte Transplantat, das in einer unkomplizierten, nur 10 Einheiten Blut und Plasma erfordernden Operation transplantiert wurde, zeigte eine Sofortfunktion. Innerhalb weniger Stunden kam es jedoch zum Funktionsverlust. Beide Transplantatversagen werden auf immunologische, einer hyperakuten Abstoßung entsprechende Vorgänge zurückgeführt. Somit konnten zwei unterschiedliche Erscheinungsformen beobachtet werden: der sogenannte “Delayed Type” bei der ersten Patientin und die mehr klassische Form bei dem zweiten Patienten. Für die Diagnosestellung „hyperakute Abstoßung” werden zwei Befunde für erforderlich gehalten: 1. histologische Befunde von Nekrosen und herdförmige Immunglobulinablagerungen, besonders IgG, IgM, IgA, C3-Komplement-Komponente, Properdin und Fibrinogen, und 2. der Nachweis zumindest einer kurzzeitigen initialen Transplantatfunktion, um eine initiale Nichtfunktion aufgrund anderer Ursachen auszuschließen. Die seltene Diagnosestellung bei der klassischen Form einer hyperakuten Abstoßung und hypothetische Gründe für die häufigere Beobachtung des “Delayed Type” werden diskutiert.SummaryOut of 81 liver transplantations 2 graft failures were diagnosed to be due to hyperacute rejection. In the first patient the operative procedure was difficult requiring 19 units of blood and plasma, but the graft was functioning well from the beginning until day 1–2, when rapid deterioration occurred. The cross-match was positive. The second patient received a third graft after the first graft had failed due to donor reasons and the second ABO-incompatible graft had been rejected. The third graft transplanted in an uncomplicated operation requiring only 10 units of blood and plasma failed within hours. Both incidences are throught to be a consequence of an immunological assault, consistent with hyperacute rejection. Thus two different clinical appearances could be observed: the so-called delayed type in the first patient and the more classical type in the second patient. For establishing diagnosis of hyperacute rejection two prerequisites were considered essential: 1) histological findings of necrosis and patchy deposits of immunoglobulins, namely IgG, IgM, IgA, C-3 complement component, properdine and fibrinogen, and 2) the proof of at least a short period of an initial function of the graft prior to deterioration in order to exclude primary non-function due to other causes. The low frequency of the appearance of the classical hyperacute rejection and hypothetical causes for the more frequent appearance of the delayed type are discussed.

Anesthesiological management during isolated liver perfusion.

The treatment of irresectable hepatic metastases is limited by the systemic toxicity of anticancer agents. Isolated hyperthermic liver perfusion (IHLP) with anticancer agents is a new therapy for irresectable liver tumors. The risks of this therapy lie in the extended operation, the anhepatic phase and the possibility of liver damage due to the anticancer drug and hyperthermia. Experience of this method is rare, and the side effects are not well known. To estimate the individual risk of patients before isolated liver perfusion an extended evaluation of the preoperative conditions is usual. Titration of all anesthetic agents is advisable to prevent cardiovascular changes and to avoid an extended recovery time after therapy. Based on our experience with IHLP in ten patients, we prefer coinduction with midazolam and thiopentone. After intubation, intermittent positive pressure ventilation with positive end-expiratory pressure is instituted with 30% oxygen in air. Pancuronium bromide is used to provide muscular paralysis, and isoflurane is administered throughout the procedure. Anesthesia is supplemented by fentanyl and midazolam. Invasive hemodynamic monitors may be placed after induction of anesthesia. Our first results with IHLP indicate that, under the conditions of elevated monitoring, complete isolation of the liver, a good wash-out and a safe anesthesiological management, no major disturbances must be expected during the therapy. The patients are more compromised by the therapy during the following days. Low diastolic blood pressure and loss of resistance after perfusion were the first signs of a toxic reaction.

The surgical technique of isolated hyperthermic arterial liver perfusion in humans.

Various techniques of isolated liver perfusions have been described, using hepatic artery or both hepatic artery and portal vein. In this paper the technique of isolated arterial liver perfusion is presented. Twelve patients suffering from non-resectable liver tumors underwent this approach. All of them had been previously unsuccessfully treated by resection or systemic chemotherapy. The liver perfusions were performed without technical problems. No operative death occurred. The mean operating time was 413 +/- 29 min. Although the perfusion medium was oxygenated and the absolute anoxic period was shorter than 10 min in all cases the perfused livers showed a marked postoperative increase of liver enzyme levels. Further studies should be aimed at reducing this hepatic injury and simplifying the complex surgical procedure.