Hepatic artery reconstruction using an operating microscope in pediatric liver transplantation-Is it worth the effort?

INTRODUCTION: In pediatric liver transplantation (pLT), hepatic artery thrombosis (HAT) is associated with inferior transplant outcome. Hepatic artery reconstruction (HAR) using an operating microscope (OM) is considered to reduce the incidence of HAT. METHODS: HAR using an OM was compared to a historic cohort using surgical loupes (SL) in pLT performed between 2009 and 2020. Primary endpoint was the occurrence of HAT. Secondary endpoints were 1-year patient and graft survival determined by Kaplan-Meier analysis and complications. Multivariate analysis was used to identify independent risk factors for HAT and adverse events. RESULTS: A total of 79 pLTs were performed [30 (38.0%) living donations; 49 (62.0%) postmortem donations] divided into 23 (29.1%) segment 2/3, 32 (40.5%) left lobe, 4 (5.1%) extended right lobe, and 20 (25.3%) full-size grafts. One-year patient and graft survival were both 95.2% in the OM group versus 86.2% and 77.8% in the SL group (p = .276 and p = .077). HAT rate was 0% in the OM group versus 24.1% in the SL group (p = .013). One-year patient and graft survival were 64.3% and 35.7% in patient with HAT, compared to 93.9% and 92.8% in patients with no HAT (both p < .001). Multivariate analysis revealed HAR with SL (p = .022) and deceased donor liver transplantation (DDLT) (p = .014) as independent risk factors for HAT. The occurrence of HAT was independently associated with the need for retransplantation (p < .001) and biliary leakage (p = .045). CONCLUSION: In pLT, the use of an OM is significantly associated to reduce HAT rate, biliary complications, and graft loss and outweighs the disadvantages of delayed arterial perfusion and prolonged warm ischemia time (WIT).

Plötzlicher Kindstod von zwei Säuglingen in Babytragehilfen.

Sudden unexpected death in infancy (SUDI), previously termed sudden infant death syndrome (SIDS), is the second leading cause of death in infants beyond the neonatal period in Germany, and a major cause of infant mortality in economically well developed countries (OECD Health Statistics, 2019). The risk of SUDI peaks at the age of 2-4 months and then decreases continuously till the end of the first year. A complex multifactorial cause, rather than a single characteristic factor, may cause SUDI within a critical period of infant development (Guntheroth WG et al., Pediatrics 2002; 110: e64-e64). Risk factors include prematurity, male gender, bottle-feeding, prone sleeping position, overheating, as well as exposure to smoke amongst others (Carpenter RG et al., Lancet 2004; 363: 185-191). Thus, health professionals consistently advise and educate parents about avoidable risk factors of SUDI at routine well-baby examinations. Since the advent of SUDI prevention strategies in the 1980s, the incidence has decreased 10fold, from 1,55/1.000 live births in 1991 to 0,15/1000 in 2015. This number seems to have reached a steady state (Statistisches Bundesamt Germany, 2015).

Severe Traumatic Brain Injury in children-paradigm of decompressive craniectomy compared to a historic cohort.

PURPOSE: Traumatic brain injury (TBI) is one of the leading causes of death and disability in children. Medical therapy remains limited, and decompressive craniectomy (DC) is an established rescue therapy in case of elevated intracranial pressure (ICP). Much discussion deals with clinical outcome after severe TBI treated with DC, while data on the pediatric population is rare. We report our experience of treating severe TBI in two different treatment setups at the same academic institution. METHODS: Forty-eight patients (≤ 16 years) were hospitalized with severe TBI (GCS ≤ 8 points) between 2008 and 2018 in a pediatric intensive care unit (ICU) at a specialized tertiary pediatric care center. Data on treatment, clinical status, and outcome was retrospectively analyzed. Outcome data included Glasgow Outcome Scale (GOS) at 3-, 12-, and 36-month follow-up. Data was compared to a historic cohort with 53 pediatric severe TBI patients treated at the same institution in a neurointensive care unit between 1996 and 2007. Ethical approval was granted (EA2/076/21). RESULTS: Between 2008 and 2018, 11 patients were treated with DC. Compared to the historic cohort, patients were younger and GCS was worse, while in-hospital mortality and clinical outcome remained similar. A trend towards more aggressive EVD placement and the internal paradigm change for treatment in a specialized pediatric ICU was observed. CONCLUSIONS: In children with severe TBI treated over two decades, clinical outcome was comparable and mostly favorable in two different treatment setups. Consequent therapy is warranted to maintain the positive potential for favorable outcome in children with severe TBI.

Complement activation in children with Streptococcus pneumoniae associated hemolytic uremic syndrome.

BACKGROUND: Hemolytic uremic syndrome caused by invasive pneumococcal disease (P-HUS) is rare in children and adolescents, but accompanied by high mortality in the acute phase and complicated by long-term renal sequelae. Abnormalities in the alternative complement pathway may additionally be contributing to the course of the disease but also to putative treatment options. METHODS: Retrospective study to assess clinical course and laboratory data of the acute phase and outcome of children with P-HUS. RESULTS: We report on seven children (median age 12 months, range 3-28 months) diagnosed with P-HUS. Primary organ manifestation was meningitis in four and pneumonia in three patients. All patients required dialysis which could be discontinued in five of them after a median of 25 days. In two patients, broad functional and genetic complement analysis was performed and revealed alternative pathway activation and risk haplotypes in both. Three patients were treated with the complement C5 inhibitor eculizumab. During a median follow-up time of 11.3 years, one patient died due to infectious complications after transplantation. Two patients showed no signs of renal sequelae. CONCLUSIONS: Although pathophysiology in P-HUS remains as yet incompletely understood, disordered complement regulation seems to provide a clue to additional insights for pathology, diagnosis, and even targeted treatment.

Outcome after pediatric liver transplantation for staged abdominal wall closure with use of biological mesh-Study with long-term follow-up.

Abdominal wall closure after pediatric liver transplantation (pLT) in infants may be hampered by graft-to-recipient size discrepancy. Herein, we describe the use of a porcine dermal collagen acellular graft (PDCG) as a biological mesh (BM) for abdominal wall closure in pLT recipients. Patients <2 years of age, who underwent pLT from 2011 to 2014, were analyzed, divided into definite abdominal wall closure with and without implantation of a BM. Primary end-point was the occurrence of postoperative abdominal wall infection. Secondary end-points included 1- and 5-year patient and graft survival and the development of abdominal wall hernia. In five out of 21 pLT recipients (23.8%), direct abdominal wall closure was achieved, whereas 16 recipients (76.2%) received a BM. BM removal was necessary in one patient (6.3%) due to abdominal wall infection, whereas no abdominal wall infection occurred in the no-BM group. No significant differences between the two groups were observed for 1- and 5-year patient and graft survival. Two late abdominal wall hernias were observed in the BM group vs none in the no-BM group. Definite abdominal wall closure with a BM after pLT is feasible and safe when direct closure cannot be achieved with comparable postoperative patient and graft survival rates.

Single-Pass Albumin Dialysis in the Treatment of Children with Liver Failure.

BACKGROUND AND AIMS: Acute and acute on chronic liver failure are life-threatening conditions, and bridging to transplantation is complicated by a paucity of suitable organs for children. While different modalities of extracorporeal liver support exist, their use in children is complicated by a large extracorporeal volume, and data on their use in children is limited. The aim of this analysis was to investigate the efficacy and safety of single-pass albumin dialysis (SPAD) in children with liver failure. METHODS: Retrospective medical chart review of pediatric patients with liver failure treated with SPAD. The decrease in hepatic encephalopathy (HE) and the serum levels of bilirubin and ammonia were measured to determine efficacy. Adverse events were documented to assess safety. RESULTS: Nineteen pediatric patients with a median age of 25.5 months and a median body weight of 11.9 kg were treated with SPAD between January 2011 and March 2018. Total bilirubin (p < 0.001) and ammonia (p = 0.02) significantly decreased after treatment with SPAD. As clinical outcome parameter, HE significantly improved (p = 0.001). Twelve patients were bridged successfully to liver transplantation. In all patients, 71 SPAD sessions were run. Clotting in the dialysis circuit was observed in 49% of all sessions. Heparin and citrate were used for anticoagulation and were significantly superior to dialysis without any anticoagulation (p= 0.03). Transfusion of packed blood cells (57%) and catecholamine therapy (49%) were frequently necessary. CONCLUSIONS: Treatment with SPAD was effective in detoxification, as measured by significant improvement of HE and clearance from surrogate laboratory parameters.

[New Challenges: Diagnosis of Brain Death in Newborn, Children and Adolescents]. / Neue Herausforderungen: Feststellung des irreversiblen Ausfalls der Hirnfunktion bei Neugeborenen, Kindern und Jugendlichen.

BACKGROUND: According to the current update of the German guideline on brain death (BD), participation of paediatricians is now mandatory for the examination of BD in patients younger than 14 years. The present analysis focuses on the previous practice and highlights the challenges that arise from the current update. METHODS: Retrospective evaluation of the patient registry of the German organ procurement organisation (north-eastern bureau) between January, 2001 and December, 2010 with specified paediatric age groups according to the 4th update of the German guideline on BD from the 1st of July 2015. RESULTS: 133 patients (0-17 years) received at least one BD examination. Secondary brain damage was most frequent within the first 6 months of life whereas traumatic and other causes of primary brain damage were predominantly observed thereafter. The number of patients who received BD examination by paediatricians or were treated on neonatal/paediatric intensive care units declined with increasing age. In more than two-third of all paediatric patients, no paediatrician was involved in BD diagnostics. DISCUSSION: After enforcement of the 4th update of the German guideline on BD, the participation of qualified paediatric physicians must be increased significantly compared to previous practice. Advancements in the specialist training of paediatric physicians, adjustments in patient-centered paediatric care and interdisciplinary diagnostic teams may be solutions to meet this demand.

Ibuprofen and indomethacin differentially regulate vascular endothelial growth factor and its receptors in ductus arteriosus endothelial cells.

BACKGROUND: Cyclooxygenase inhibitors are widely applied to facilitate ductal closure in preterm infants. The mechanisms that lead to patent ductus arteriosus closure are incompletely understood. Vascular endothelial growth factor plays pivotal roles during ductal closure and remodelling. Aim The aim of this study was to investigate the effects of ibuprofen and indomethacin on the expression of vascular endothelial growth factor and its receptors in a primary rat ductus arteriosus endothelial cell culture. METHODS: Protein expression of vascular endothelial growth factor and vascular endothelial growth factor receptor 1 and 2 was confirmed in rat ductus arteriosus and aorta by immunofluorescence staining. Fetal rat endothelial cells were isolated from ductus arteriosus and aorta using immunomagnetic cell sorting and treated with ibuprofen or indomethacin. mRNA expression levels were assessed by quantitative polymerase chain reaction analysis. RESULTS: In ductal endothelial cells, ibuprofen significantly induced vascular endothelial growth factor and its receptor 2, but not receptor 1, whereas indomethacin did not alter the expression levels of the vascular endothelial growth factor system. In contrast, ibuprofen significantly induced vascular endothelial growth factor and its receptors 1 and 2 in aortic endothelial cells, whereas indomethacin only induced vascular endothelial growth factor receptor 2. CONCLUSION: Our results indicate differential effects of ibuprofen and indomethacin on the expression levels of the vascular endothelial growth factor system in ductus arteriosus endothelial cells. In addition, vessel-specific differences between ductal and aortic endothelial cells were found. Further in vivo studies are needed to elucidate the biological significance of these findings.

Observational clinical study on organ dysfunction associated with dosing of antibiotics in a Pediatric Intensive Care Unit.

BACKGROUND: Medication errors are of concern especially in pediatric patients. This study investigates impact of dosing errors of antibiotics on outcome in critically ill pediatric patients. METHODS: Retrospective study including all consecutive patients admitted to one university pediatric intensive care unit (PICU) in 2010 with length of PICU stay >24 hrs, age <18 years and antibiotic therapy. Antibiotic dosages were evaluated for compliance with recommended dosing individually adapted for bodyweight, age and organ function. Primary endpoint was organ dysfunction defined as occurrence of liver injury (LI) or acute kidney injury (AKI) after initiation of antibiotic therapy. AKI was defined as reduced estimated glomerular filtration below 50 mL/min or renal replacement therapy. LI was defined as more than two-fold elevation of liver enzymes. Additionally, duration of PICU stay, ventilation and all-cause PICU mortality were investigated. RESULTS: Altogether 305 patients were evaluated with 2577 patient PICU days and 4021 antibiotic dosages. Overall 38.6% of dosages were incorrect according to recommendations and were applied in 130 patients (low-adherence-group). 175 children received antibiotic dosing according to recommendations (high-adherence-group). Patients in the low-adherence-group showed a 7-fold increase in adjusted risk to develop new-onset organ dysfunction (95% CI: 2.1-26.4), needed longer median PICU treatment (7 versus 3 days, P<0.001) and prolonged duration of mechanical ventilation (8 versus 2 days, P<0.001). In subgroup analyses, organ dysfunction and PICU mortality were associated with non-adherence to recommendations. CONCLUSIONS: Adherence to a bodyweight- and age-adapted dosage-protocol is associated with less organ dysfunction and a more favorable clinical outcome in pediatric patients.

A European multicenter outcome study on the different perioperative airway management policies following midface surgery in syndromic craniosynostosis: a proposal for a Standard Operating Procedure.

BACKGROUND: Perioperative airway management following midface advancements in children with Apert and Crouzon/Pfeiffer syndrome can be challenging, and protocols often differ. This study examined airway management following midface advancements and postoperative respiratory complications. METHODS: A multicenter, retrospective cohort study was performed to obtain information about the timing of extubation, perioperative airway management, and respiratory complications after monobloc / le Fort III procedures. RESULTS: Ultimately, 275 patients (129 monobloc and 146 Le Fort III) were included; 62 received immediate extubation and 162 delayed extubation; 42 had long-term tracheostomies and nine perioperative short-term tracheostomies. Short-term tracheostomies were in most centers reserved for selected cases. Patients with delayed extubation remained intubated for three days (IQR 2 - 5). The rate of no or only oxygen support after extubation was comparable between patients with immediate and delayed extubation, 58/62 (94%) and 137/162 (85%) patients, respectively. However, patients with immediate extubation developed less postoperative pneumonia than those with delayed, 0/62 (0%) versus 24/161 (15%) (P = 0.001), respectively. Immediate extubation also appeared safe in moderate/severe OSA since 19/20 (95%) required either no or only oxygen support after extubation. The odds of developing intubation-related complications increased by 21% with every extra day of intubation. CONCLUSIONS: Immediate extubation following midface advancements was found to be a safe option, as it was not associated with respiratory insufficiency but did lead to fewer complications. Immediate extubation should be considered routine management in patients with no/mild OSA and should be the aim in moderate/severe OSA after careful assessment.

Treatment of pediatric convulsive status epilepticus.

Status epilepticus is one of the most common life-threatening neurological emergencies in childhood with the highest incidence in the first 5 years of life and high mortality and morbidity rates. Although it is known that a delayed treatment and a prolonged seizure can cause permanent brain damage, there is evidence that current treatments may be delayed and the medication doses administered are insufficient. Here, we summarize current knowledge on treatment of convulsive status epilepticus in childhood and propose a treatment algorithm. We performed a structured literature search via PubMed and ClinicalTrails.org and identified 35 prospective and retrospective studies on children <18 years comparing two and more treatment options for status epilepticus. The studies were divided into the commonly used treatment phases. As a first-line treatment, benzodiazepines buccal/rectal/intramuscular/intravenous are recommended. For status epilepticus treated with benzodiazepine refractory, no superiority of fosphenytoin, levetirazetam, or phenobarbital was identified. There is limited data on third-line treatments for refractory status epilepticus lasting >30 min. Our proposed treatment algorithm, especially for children with SE, is for in and out-of-hospital onset aids to promote the establishment and distribution of guidelines to address the treatment delay aggressively and to reduce putative permanent neuronal damage. Further studies are needed to evaluate if these algorithms decrease long-term damage and how to treat refractory status epilepticus lasting >30 min.

Loss of cerebral blood flow and cerebral perfusion pressure in brain death: A transcranial Duplex ultrasonography study.

PURPOSE: We investigated cerebral perfusion pressure (CPP) at the time loss of cerebral blood flow (CBF) occurred during brain death (BD). We hypothesized that a critical closing pressure (CrCP) may be reached before CPP drops to 0 mmHg. MATERIALS AND METHODS: 14 patients with increasing intracranial pressure (ICP) leading to BD were included. Transcranial Duplex (TCD) ultrasonography was used to investigate CBF. Starting at a CPP of 30 mmHg, TCD was repeated until waveforms indicated loss of CBF. We then analyzed CPP by the time TCD indicated absent CBF and clinical BD was established. RESULTS: In 12 patients, CPP was positive when clinical BD was manifest and TCD illustrated absent CBF. Across all patients, mean CPP at clinical BD manifestation was 10.0 mmHg (range 0-20 mmHg); mean CPP by the time CBF stopped was 7.5 mmHg (0-20 mmHg). In four patients, clinical BD preceded loss of CBF. Here, the mean CPP difference from clinical BD to loss of CBF was 8.8 mmHg (5-15 mmHg). CONCLUSIONS: CrCP may be reached although CPP is still positive, resulting in complete loss of CBF and BD. By including bedside TCD, neuromonitoring may contribute to early identification of patients at risk to experience loss of CBF and subsequent BD.

Pneumonia in pediatric critical care medicine and the adherence to guidelines.

BACKGROUND: Different studies in adults reported significant outcome improvement for patients treated with high adherence to guidelines. The present study was initiated to evaluate the impact of adherence to antibiotic prescription guidelines on health outcomes of children on pediatric Intensive Care Unit (PICU) suffering from pneumonia. METHODS: This retrospective cohort study was conducted on a pediatric Intensive Care Unit at Charité Hospital Berlin. All patients with a length of stay (LOS) >24 hours, age <18 years, antimicrobial therapies, and a radiologically confirmed diagnosis of pneumonia according to the "Centers for Disease Control and Prevention" definitions were included during the study period of 2009 and 2010. Adherence to national guidelines was evaluated daily and two groups were defined: Low adherence group (LAG) with a presence of <70% of days with compliant therapy and high adherence group (HAG) with an adherence of ≥70%. RESULTS: High adherence was observed in 65 patients compared with 61 in low-adherence group. Number of patients needing invasive ventilation did not vary between HAG and LAG (N.=37 vs. N.=41; P=0.235). There was a statistically significant shorter duration of ventilation in HAG patients (P=0.031). Time to clinical recovery from pneumonia tended to be shorter in HAG patients (7.5d vs. 10.9d; P=0.07). There was a significant reduction in LOS in HAG patients (9.3d vs. 13.7d; P=0.016). However, mortality appeared comparable between groups. CONCLUSIONS: Similar to previous evidence in adult patients, children with pneumonia seem to benefit from guideline-based antibiotic therapy. Further studies are needed to explore strategies to improve guideline adherence.

Modified Zipper Method, a Promising Treatment Option in Severe Pediatric Immune-Mediated Neurologic Disorders.

OBJECTIVE: To introduce and evaluate a modified version of the "zipper method"-a treatment strategy alternating intravenous immunoglobulin (IVIG) and plasma exchange (PLEX) first reported for 9 pediatric cases of Guillain-Barré syndrome in 2018-for treatment of severe immune-mediated neurologic disorders in children. METHODS: The modified zipper method comprised longer intervals between PLEX-IVIG cycles (48 hours instead of 24 hours), more cycles (7-10 instead of 5), a consistent plasma volume exchange (instead of the original multistep approach), and variable infusion times for IVIGs (4-8 hours). The modified zipper method was applied as an individual treatment approach once standard therapy failed. The follow-up ranged from 6 months to 2 years. Cases were analyzed retrospectively. Disease severity was mainly quantified by the Guillain-Barré syndrome disability score. RESULTS: Four children (9-15 years) with (1) Miller-Fisher syndrome, (2) Bickerstaff brainstem encephalitis, (3) common Guillain-Barré syndrome, and (4) severe acute disseminated encephalomyelitis were treated by the modified zipper method. Results for duration of mechanical ventilation (median of 12 days, interquartile range [IQR] 8-16), hospital stay (median of 23 days, IQR 22-24), and time to unaided walking (median of 22 days, IQR 21-37) outperformed previous studies with IVIG/PLEX alone or IVIG + PLEX combinations unlike the zipper method. CONCLUSION: The modified zipper method is associated with a low mortality, a short mechanical ventilation time, a short hospital stay, and an excellent outcome in children with severe Guillain-Barré syndrome or acute disseminated encephalomyelitis. Our regimen is streamlined for applicability. Results emphasize its robust effectiveness as an option for therapy escalation in severe neuroimmunologic diseases. Now, multicenter trials are needed to evaluate this novel treatment strategy.

Over 30 Years of Pediatric Liver Transplantation at the Charité-Universitätsmedizin Berlin.

BACKGROUND: Pediatric liver transplantation (LT) is the treatment of choice for children with end-stage liver disease and in certain cases of hepatic malignancies. Due to low case numbers, a technically demanding procedure, the need for highly specialized perioperative intensive care, and immunological, as well as infectious, challenges, the highest level of interdisciplinary cooperation is required. The aim of our study was to analyze short- and long-term outcomes of pediatric LT in our center. METHODS: We conducted a retrospective single-center analysis of all liver transplantations in pediatric patients (≤16 years) performed at the Department of Surgery, Charité - Universitätsmedizin Berlin between 1991 and 2021. Three historic cohorts (1991-2004, 2005-2014 and 2015-2021) were defined. Graft- and patient survival, as well as perioperative parameters were analyzed. The study was approved by the institutional ethics board. RESULTS: Over the course of the 30-year study period, 212 pediatric LTs were performed at our center. The median patient age was 2 years (IQR 11 years). Gender was equally distributed (52% female patients). The main indications for liver transplantation were biliary atresia (34%), acute hepatic necrosis (27%) and metabolic diseases (13%). The rate of living donor LT was 25%. The median cold ischemia time for donation after brain death (DBD) LT was 9 h and 33 min (IQR 3 h and 46 min). The overall donor age was 15 years for DBD donors and 32 years for living donors. Overall, respective 1, 5, 10 and 30-year patient and graft survivals were 86%, 82%, 78% and 65%, and 78%, 74%, 69% and 55%. One-year patient survival was 85%, 84% and 93% in the first, second and third cohort, respectively (p = 0.14). The overall re-transplantation rate was 12% (n = 26), with 5 patients (2%) requiring re-transplantation within the first 30 days. CONCLUSION: The excellent long-term survival over 30 years showcases the effectiveness of liver transplantation in pediatric patients. Despite a decrease in DBD organ donation, patient survival improved, attributed, besides refinements in surgical technique, mainly to improved interdisciplinary collaboration and management of perioperative complications.

Viral infections in hospitalized children in Germany during the COVID-19 pandemic: Association with non-pharmaceutical interventions.

Background: Non-pharmaceutical interventions (NPI) during the COVID-19 pandemic aimed at prevention of SARS-CoV-2 transmission also influenced transmission of viruses other than SARS-CoV-2. The aim of this study was to describe and compare the burden of common viral respiratory and gastrointestinal infections in children admitted to Berlin University Children's Hospital (BCH) before and during the COVID-19 pandemic at different levels of public NPI measures. Methods: In this retrospective study, we analyzed the frequency of detection of common human respiratory and gastrointestinal viruses from January 2016 through January 2022 in all patients admitted to BCH. We compared virus detection before and during the COVID-19 pandemic at different levels of public NPI measures. Results: The frequency of detection of seasonal enveloped and non-enveloped viruses [Boca-, Corona-, Influenza-, Metapneumo-, Parainfluenza-, Rota-, and Respiratory Syncytial Viruses (RSV)] was diminished during the COVID-19 pandemic, whereas detection rates of non-seasonal viruses (Rhino-/Entero-, and Adenoviruses) were stable during the pandemic. After withdrawal of major NPI measures, we observed an out of season surge of the detection rates of Boca-, Corona-, Parainfluenzaviruses, and RSV. In contrast, no increased detection frequency was observed for Influenza-, Metapneumo-, and Rotaviruses as of January 2022. Conclusion: Corona-, Boca-, Parainfluenzaviruses, and RSV returned as frequently detected pathogens after withdrawal of major NPI measures. The out of season rise might be attributed to an "immune-debt" due to missing contact to viral antigens resulting in waning of population immunity during the COVID-19 pandemic.

Isolation and culture of fibroblasts, vascular smooth muscle, and endothelial cells from the fetal rat ductus arteriosus.

The ductus arteriosus (DA), a fetal arterial shunt vessel between the proximal descending aorta and the pulmonary artery, closes shortly after birth. Initial functional closure as a result of the DA's smooth muscle contraction is followed by definite anatomical closure. The latter involves several complex mechanisms like endothelial cushion formation and smooth muscle cell migration resulting in fibrosis and sealing of the vessel. These complex steps indicate highly specialized functions of the DA vascular smooth muscle cells (VSMCs), endothelial cells, and fibroblasts. Herein, we describe a new reproducible method for isolating VSMCs, endothelial cells, and fibroblasts of high viability from fetal rat DA using immunomagnetic cell sorting. Purity of the different cell cultures was assessed by immunohistochemistry and flow cytometry and ranged between 85 and 94%. The capability of the VSMCs to react to hypoxic stimuli was assessed by intracellular calcium and ATP measurements and by VEGF mRNA expression analysis. VSMCs respond to hypoxia with decreases in intracellular calcium concentrations and ATP levels, whereas VEGF mRNA expression increased 3.2-fold. The purified vessel-specific different cell types are suitable for subsequent gene expression profiling and functional studies and provide important tools for improving our understanding of the complex processes involved in the closure of the DA.

Continuous veno-venous single-pass albumin hemodiafiltration in children with acute liver failure.

OBJECTIVE: To investigate the applicability, efficacy, and safety of single-pass albumin dialysis in children. DESIGN: Retrospective data review of uncontrolled clinical data. SETTING: University-based pediatric intensive care unit collaborating with a local center for liver transplantation. PATIENTS: Nine children, aged 2 to 15 yrs, who were treated with single-pass albumin dialysis for acute liver failure of various origins under a compassionate-use protocol between 2000 and 2006. All patients met high-urgency liver transplantation criteria. INTERVENTIONS: Single-pass albumin dialysis was performed as rescue therapy for children with acute liver failure. MEASUREMENTS AND MAIN RESULTS: The decrease in hepatic encephalopathy (grades 1-4) and the serum levels of bilirubin, bile acids, and ammonium were measured to assess the efficacy of detoxification. As a measure of liver synthesis function, thromboplastin time and fibrinogen were analyzed. The safety of the procedure was assessed by documenting adverse effects on mean arterial blood pressure, platelet count, and clinical course. Seven out of nine patients were bridged successfully to either native organ recovery (n = 1) or liver transplantation (n = 6), one of them twice. Six out of nine patients undergoing single-pass albumin dialysis (ten treatments) survived. In six patients, hepatic encephalopathy could be reduced at least by one degree. Ammonium, bilirubin, and bile acid levels decreased in all patients. One patient had an allergic reaction to albumin. CONCLUSIONS: In childhood acute liver failure, treatment with single-pass albumin dialysis was generally well tolerated and seems to be effective in detoxification and in improving blood pressure, thus stabilizing the critical condition of children before liver transplantation and facilitating bridging to liver transplantation. It may be beneficial in avoiding severe neurologic sequelae after acute liver failure and thereby improve survival. Single-pass albumin dialysis is an inexpensive albumin-based detoxification system that is easy to set up and requires little training. Whether and to what extent single-pass albumin dialysis can support children with acute liver failure until native liver recovery remains unclear.