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Zusammenfassung: Die Lebertransplantation ist bei Kindern mit akutem und chronischem Leberversagen, metabolischen Lebererkrankungen und -tumoren die Therapie der Wahl. Bei den meist sehr kleinen Empfängern sind die Ressourcen größenkompatibler Vollorgantransplantate jedoch begrenzt. Die Leberlebendspende konnte bei Kindern die Wartelistenmortalität fast vollständig eliminieren und weist exzellente Patienten- und Organüberlebensdaten auf. Da 80% der kindlichen Empfänger ein Gewicht <25 kg haben, ist die Spende der linkslateralen Lebersegmente II und III meist ausreichend. Durch eine Standardisierung des chirurgischen sowie des prä-, intra- und postoperativen Managements konnte sie zu einem Verfahren entwickelt werden, welches eine sehr niedrige Spendermorbidität und -mortalität aufweist. Die kindliche Lebendspende-Lebertransplantation setzt eine hohe Expertise in der Leberchirurgie und Splitlebertransplantation voraus und erfordert aufgrund der komplexen und oft organübergreifenden Krankheitsbilder eine enge Zusammenarbeit mit einem erfahrenen pädiatrischen Team. Sie sollte deshalb ausschließlich in Transplantationszentren durchgeführt werden, die diese Voraussetzungen erfüllen.

The T helper cell type 1 (Th1) cytokines interleukin (IL)-2 and interferon (IFN)- are mediators of acute graft rejection after liver transplantation and Th2 cytokines, such as IL-4 and IL-10, may have a protective role and correlate with graft acceptance. To test the hypothesis that infants aged <1 year have an immunological advantage with regard to graft acceptance because of a partially immature immune system with a physiological balance toward a Th2 cytokine profile, we conducted the present study.

The most common cause of portal hypertension in children with healthy livers is the prehepatic block. A 7-year-old girl had presented with portal vein thrombosis after umbilical vein catherization in the newborn period. She suffered from collateral circulation with recurrent bleeding episodes due to esophageal varices (stage III-IV) and developed hypersplenism. Ultrasound demonstrated an open branch of the left portal vein. Direct splenoportography showed an open and communicating superior mesenteric vein. Liver biopsy was normal. An autologous left jugular vein graft was used to create a bypass from the superior mesenteric vein to the umbilical portion of the left intrahepatic portal vein (mesentericoportal Rex-shunt). Postoperatively, normal intrahepatic portal vein flow was demonstrated by ultrasound. After 2 years of follow-up, the patient is asymptomatic with no signs of portal hypertension. In contrast to classic portosystemic shunt operations, this bypass restores physiological portal vein flow, thus avoiding the possible consequences of longterm portosystemic shunting and low-grade encephalopathy. Die häufigste Ursache einer portalen Hypertension bei Kindern mit nichtfibrotischer Leber ist die extrahepatische Pfortaderthrombose. Ein 7 jähriges Mädchen mit Pfortaderthrombose nach Katheterismus und folgender Nabelvenenentzündung wurde klinisch mit rezidivierenden Oesophagusvaricenblutungen Grad III-IV und Hypersplenismus auffällig. Bioptisch lag eine normale Leberhistologie vor. Dopplersonographisch konnte ein erhaltener linker Pfortaderast nachgewiesen werden. In der direkten Splenoportographie war eine offene V. mesenterica superior darstellbar. Es folgte der Entschluß zur Operation mit autologer Implantation der linken V. jugularis interna als Bypass von der V. mesenterica superior zum umbilicalen Anteil der linken intrahepatischen V. portae. Intra- und postoperativ zeigten sich dopplersonographisch intrahepatisch in der V. portae regelrechte Strömungsverhältnisse. Zwei Jahre nach der Operation sind die Zeichen der portalen Hypertension nicht mehr nachweisbar. Im Gegensatz zu den portosystemischen Shunts wird durch diesen Bypass die physiologische Pfortaderversorgung wiederhergestellt, wodurch die möglichen Komplikationen der portosystemischen Shunts vermieden werden können.

Abstract: Introduction: Living- related liver transplantation (LRLT) for paediatric recipients was developed 10 years ago to overcome the high mortality on the waiting list. Since then, liver transplantation programs around the world have begun to employ this method with encouraging results. This review describes the actual status of LRLT in children, aspects of donor selection, donor risks, and surgical technique, as well as an update of the results of the leading LRLT programs in the world. The donor operation has matured to the stage of being a standardised, teachable procedure with a low risk of morbidity or mortality. However, there is a percentage of potential donations that have to be declined for medical or socio- psychological reasons. LRLT provides grafts of excellent quality and short cold ischemic times. A major advantage is the fact that the optimal moment for the transplantation procedure can be chosen. Together with split-liver techniques, LRLT has a positive effect on the general situation of the paediatric waiting list for liver transplantation, with a reduction of pre-transplant mortality to nearly 0%.

Seventy two endoscopies of the upper gastrointestinal tract and one hundred and fifteen colonoscopies were performed in children aged nine months to seventeen years. The experience gained with different types of endoscopes suggests that endoscopy of the upper gastrointestinal tract should be only performed with pediatric instruments. These are: GIF-P12 (max. outer diameter 9 mm) and TX-72 (max. outer diameter 10 mm).

The shortage of pediatric donor livers has stimulated the development of advanced surgical approaches such as partial liver transplantation, which produces the same results as whole organ replacement. Differences in body weight between donor and recipient of more than four times, however, usually necessitate extended reduction hepatectomy and modified ways of performing vascular reconstruction. Therefore, following ex vivo “trisegmentectomy”, a new technique of hepatic venous drainage was developed with an end-to-side anastomosis of the left donor hepatic vein to the preserved recipient inferior vena cava. This operative technique was applied to four children, one of whom had a retransplantation performed in exactly the same fashion. There were no specific complications related to this particular surgical technique. From our preliminary experience we conclude that reduced-size liver transplantation can be safely performed with the described type of hepatic vein reconstruction, especially when large donor organs have to be used for small children.

Abstract. In order to obtain a better resolution of circulating PTH-fragments, we developed a radioimmunoassay with an antiserum raised against the synthetic 70–84 hPTH molecule in a sheep. [125I](69 Tyr) 70–84 hPTH was used as the radioactive tracer with the antiserum at a final dilution of 1:200 000. Displacement curves showed that only the 70–84 hPTH, (69 Tyr) 70–84 hPTH and 53–84 hPTH fragments were able to compete with the tracer. Synthetic 28–48 hPTH, 44–68 hPTH, (61 Tyr) 62–68 hPTH, purified 1–84 hPTH and 53–84 bPTH showed no ability to displace the tracer indicating that the idiotype of the antibody is directed against the 70–84 portion that is usually hidden within the globular structure of the intact molecule. Healthy adults revealed PTH-peptide levels of 153 ± 86 pg/ml (mean ± 2 sd); 2 sdrange: 67–239 pg/ml.C-terminal PTH-peptide (70–84 hPTH) concentration was normal in patients with primary hyperparathyroidism and chronic renal failure, thus excluding that neither the kidney nor the parathyroid gland is involved in the generation of this C-terminal PTH-peptide sequence. Increased levels of 70–84 hPTH immunoreactivity were found in most individuals with severe cholestatic liver disease. Since the liver appears to be responsible for part of the peripheral PTH metabolism, this assay system might be used as an indicator of altered liver function.

The pre-operative risk of paediatric liver transplantation candidates (n=41) was assessed in a prospective study by means of clinical symptoms, conventional static and liver blood flow dependent dynamic liver function tests. Nine patients died during the 365-day waiting period. The data were subjected as covariates to a survival analysis in the Cox proportional hazards model. There was a significant relationsship between the results of mono-ethylglycinexylidide (MEGX) formation and ICG test and the 365-day survival rate. In the stepwise analysis, none of the remaining parameters improved the predictive ability when added to the dynamic liver function test results. The assessment of post-transplantation liver function was studied in 27 patients during the first 28 postoperative-day period. In addition, liver function was studied in a cross-sectional study 1–7 years after successful liver transplantation in children with complete or partial rehabilitation. In the early postoperative period severe organ damage was indicated by both static and dynamic liver function tests. In the later course after transplantation no deterioration of liver function measured with MEGX formation was to be observed. These findings demonstrate the usefulness of dynamic liver function tests in the pre- and post-transplant assessment of liver function.

Summary Among the worldwide accepted indications for liver transplantation, inherited metabolic disorders play an increasing role. In some paediatric centres this indication runs second after extrahepatic biliary atresia.

Changes in arterial blood ketone body ratio (KBR) were investigated in 47 human liver transplantations. Of the 20 grafts preserved with University of Wisconsin (UW) solution, 10 had a cold preservation period of less than 10 h (UWS group) and 10 of more than 10 h (UWL group). In 27 other cases, grafts were preserved with EuroCollins (EC) solution for less than 10 h (EC group). In the EC group, KBR increased over 0.7 within 6 h after reperfusion of the graft in 17 cases (63%) and within 24 h in 7 cases (26%). In the 3 other cases, KBR failed to recover, and these patients underwent retransplantation. In the UW group, KBR recovered within 6 h in 13 cases (65%) and within 24 h in 7 cases (35%). There were no significant differences between the UWS and UWL groups. It is shown that the mitochondrial function of liver grafts preserved with UW solution can be well maintained even after extended preservation periods of more than 10 h.

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A method for rapid assessment of hepatic function in liver donors based on the formation of the lignocaine metabolite monoethylglycinexylidide (MEGX), was used in a prospective study of 69 donor-recipient pairs. The probability of graft survival over 120 days was significantly higher for livers from donors with MEGX test values above 90 μg/l than for those from donors with MEGX values of 90 μg/l or below. Other liver function tests (bilirubin, prothrombin time, activity of aminotransferases, glutamate dehydrogenase, and cholinesterase, indocyanine green clearance, and galactose elimination capacity) were inefficient at predicting early outcome of transplantation. For a 20-day graft survival, the MEGX test showed prognostic sensitivity of 73% and specificity of 78%. These findings suggest that the MEGX formation test could be valuable for selection of donor organs.

Posttransplant lymphoproliferative disorders (PTLD) have been recognized as severe side effects of immunosuppressive therapy after organ transplantation. However, no standard diagnostic and therapeutic approaches have been defined. Furthermore, few interdisciplinary perspectives comparing patients with heart/liver/kidney transplants are available. Here, we present results of a multicenter, retrospective analysis of pediatric patients treated for PTLD in Germany and Switzerland from 1990 to 2003. Patients were recruited by surveys through the working groups of pediatric renal, liver, and heart/lung transplantation as well as from the registry of pediatric Non-Hodgkin’s lymphomas (NHL-BFM). Inclusion criteria consisted of a history of solid organ transplantation, biopsy-proven diagnosis of PTLD, and age at onset of PTLD 18 years of less. Patient charts were analyzed for clinical course from transplant to onset of PTLD, virus serology, treatment regimen, and outcome. A total of 53 patients from 19 centers could be included, among them 25 renal graft recipients, 14 heart-, 11 liver-, and 1 lung transplant recipients as well as 2 patients after combined heart/lung transplantation. PTLD was diagnosed at a median time of 34 months [range 2 – 119 months] post organ transplantation. Histological evaluation based on the WHO classification showed 2 early lesion PTLD, 8 polymorphic PTLD, 26 high-grade B-cell lymphomas, 12 Burkitt-like lymphomas, 3 cases of Hodgkin’s disease and 2 T-cell lymphomas. Cytogenetic analysis revealed translocations involving chromosome 8 in five patients with Burkitt-like lymphomas. EBV gene products were detected in 31 tumors by in situ hybridization or immunohistochemistry, while 13 tumors were EBV negative (no data available on 9 tumors). EBV serology was negative in 55% of patients at the time of organ transplantation. However, in 29 patients EBV primary infection/reactivation was documented after organ transplantation (median time to infection/reactivation 5.9 months). In all patients immunosuppressive therapy was reduced. Treatment and follow up data were available in 51 patients: six patients remained in complete remission without additional treatment, in one patient autologous EBV-specific T-cells were infused. 41 patients received monoclonal antibodies (anti-CD20; n=7), chemotherapy (n=28), or a combination thereof (n=5). Fifteen of 51 patients died of progressing PTLD (n=7; among them 3 patients in which treatment was refused), treatment-related mortality (n=7), or fatal graft failure (n=2). Mortality was higher in patients with Burkitt-like lymphomas (7 of 12 patients) compared to all other entities (8 of 39 patients; p=0.026). Patients with stage IV disease had an inferior outcome compared to patients with stage I-III disease (mortality 6 of 7 vs. 9 of 44 patients, p=0.002). Thus, pediatric PTLD is a heterogeneous disease often associated with fatal outcome. The PED-PTLD study group has initiated a prospective multicenter trial of standardized diagnosis and treatment of PTLD after solid organ transplantation in children.