Technique of porcine liver procurement and orthotopic transplantation using an active porto-caval shunt.

The success of liver transplantation has resulted in a dramatic organ shortage. Each year, a considerable number of patients on the liver transplantation waiting list die without receiving an organ transplant or are delisted due to disease progression. Even after a successful transplantation, rejection and side effects of immunosuppression remain major concerns for graft survival and patient morbidity. Experimental animal research has been essential to the success of liver transplantation and still plays a pivotal role in the development of clinical transplantation practice. In particular, the porcine orthotopic liver transplantation model (OLTx) is optimal for clinically oriented research for its close resemblance to human size, anatomy, and physiology. Decompression of intestinal congestion during the anhepatic phase of porcine OLTx is important to guarantee reliable animal survival. The use of an active porto-caval-jugular shunt achieves excellent intestinal decompression. The system can be used for short-term as well as long-term survival experiments. The following protocol contains all technical information for a stable and reproducible liver transplantation model in pigs including post-operative animal care.

Liver transplantation in patients with end-stage liver disease requiring intensive care unit admission and intubation.

Data regarding transplantation outcomes in ventilated intensive care unit (ICU)-dependent patients with end-stage liver disease (ESLD) are conflicting. This single-center cohort study investigated the outcomes of patients with ESLD who were intubated with mechanical support before liver transplantation (LT). The ICU plus intubation group consisted of 42 patients with decompensated cirrhosis and mechanical ventilation before transplantation. LT was considered for intubated ICU patients if the fraction of inspired oxygen was ≤40% with a positive end-expiratory pressure ≤ 10, low pressor requirements, and the absence of an active infection. Intubated ICU patients were compared to 80 patients requiring ICU admission before transplantation without intubation and to 126 matched non-ICU-bound patients. Patients requiring ICU care with intubation and ICU care alone had more severe postoperative complications than non-ICU-bound patients. Intubation before transplantation was associated with more postoperative pneumonias (15% in intubated ICU transplant candidates, 5% in ICU-bound but not intubated patients, and 3% in control group patients; P = 0.02). Parameters of reperfusion injury and renal function on postoperative day (POD) 2 and POD 7 were similar in all groups. Bilirubin levels were higher in the ICU plus intubation group at POD 2 and POD 7 after transplantation but were normalized in all groups within 3 months. The ICU plus intubation group versus the ICU-only group and the non-ICU group had decreased 1-, 3-, and 5-year graft survival (81% versus 84% versus 92%, 76% versus 78% versus 87%, and 71% versus 77% versus 84%, respectively; P = 0.19), but statistical significance was not reached. A Glasgow coma scale score of <7 versus >7 before transplantation was associated with high postoperative mortality in ICU-bound patients requiring intubation (38% versus 23%; P = 0.01). In conclusion, ICU admission and mechanical ventilation should not be considered contraindications for LT. With careful patient selection, acceptable long-term outcomes can be achieved despite increased postoperative complications.

Subnormothermic ex vivo liver perfusion reduces endothelial cell and bile duct injury after donation after cardiac death pig liver transplantation.

An ischemic-type biliary stricture (ITBS) is a common feature after liver transplantation using donation after cardiac death (DCD) grafts. We compared sequential subnormothermic ex vivo liver perfusion (SNEVLP; 33°C) with cold storage (CS) for the prevention of ITBS in DCD liver grafts in pig liver transplantation (n = 5 for each group). Liver grafts were stored for 10 hours at 4°C (CS) or preserved with combined 7-hour CS and 3-hour SNEVLP. Parameters of hepatocyte [aspartate aminotransferase (AST), international normalized ratio (INR), factor V, and caspase 3 immunohistochemistry], endothelial cell (EC; CD31 immunohistochemistry and hyaluronic acid), and biliary injury and function [alkaline phosphatase (ALP), total bilirubin, and bile lactate dehydrogenase (LDH)] were determined. Long-term survival (7 days) after transplantation was similar between the SNEVLP and CS groups (60% versus 40%, P = 0.13). No difference was observed between SNEVLP- and CS-treated animals with respect to the peak of serum INR, factor V, or AST levels within 24 hours. CD31 staining 8 hours after transplantation demonstrated intact EC lining in SNEVLP-treated livers (7.3 × 10(-4) ± 2.6 × 10(-4) cells/µm(2)) but not in CS-treated livers (3.7 × 10(-4) ± 1.3 × 10(-4) cells/µm(2) , P = 0.03). Posttransplant SNEVLP animals had decreased serum ALP and serum bilirubin levels in comparison with CS animals. In addition, LDH in bile fluid was lower in SNEVLP pigs versus CS pigs (14 ± 10 versus 60 ± 18 µmol/L, P = 0.02). Bile duct histology revealed severe bile duct necrosis in 3 of 5 animals in the CS group but none in the SNEVLP group (P = 0.03). Sequential SNEVLP preservation of DCD grafts reduces bile duct and EC injury after liver transplantation.

Technique of subnormothermic ex vivo liver perfusion for the storage, assessment, and repair of marginal liver grafts.

The success of liver transplantation has resulted in a dramatic organ shortage. In most transplant regions 20-30% of patients on the waiting list for liver transplantation die without receiving an organ transplant or are delisted for disease progression. One strategy to increase the donor pool is the utilization of marginal grafts, such as fatty livers, grafts from older donors, or donation after cardiac death (DCD). The current preservation technique of cold static storage is only poorly tolerated by marginal livers resulting in significant organ damage. In addition, cold static organ storage does not allow graft assessment or repair prior to transplantation. These shortcomings of cold static preservation have triggered an interest in warm perfused organ preservation to reduce cold ischemic injury, assess liver grafts during preservation, and explore the opportunity to repair marginal livers prior to transplantation. The optimal pressure and flow conditions, perfusion temperature, composition of the perfusion solution and the need for an oxygen carrier has been controversial in the past. In spite of promising results in several animal studies, the complexity and the costs have prevented a broader clinical application so far. Recently, with enhanced technology and a better understanding of liver physiology during ex vivo perfusion the outcome of warm liver perfusion has improved and consistently good results can be achieved. This paper will provide information about liver retrieval, storage techniques, and isolated liver perfusion in pigs. We will illustrate a) the requirements to ensure sufficient oxygen supply to the organ, b) technical considerations about the perfusion machine and the perfusion solution, and c) biochemical aspects of isolated organs.

Low invasive in vivo tissue sampling for monitoring biomarkers and drugs during surgery.

The techniques currently used for drug, metabolite, and biomarker determination are based on sample collection, and therefore they are not suitable for repeated analysis because of the high invasiveness. Here, we present a novel method of biochemical analysis directly in organ during operation without need of a separate sample collection step: solid-phase microextraction (SPME). The approach is based on flexible microprobe coated with biocompatible extraction phase that is inserted to the tissue with no damage or disturbance of the organ. The method was evaluated during lung and liver transplantations using normothermic ex vivo liver perfusion (NEVLP) and ex vivo lung perfusion (EVLP). The study demonstrated feasibility of the method to extract wide range of endogenous compounds and drugs. Statistical analysis allowed observing metabolic changes of lung during cold ischemic time, perfusion, and reperfusion. It was also demonstrated that the level of drugs and their metabolites can be monitored over time. Based on the methylprednisolone as a selected example, the impairment of enzymatic properties of liver was detected in the injured organs but not in healthy control. This finding was supported by changes in pathways of endogenous metabolites. The SPME probe was also used for analysis of perfusion fluid using stopcock connection. The evaluation of biochemical profile of perfusates demonstrated potential of the approach for monitoring organ function during ex vivo perfusion. The simplicity of the device makes it convenient to use by medical personnel. With the microprobe, different areas of the organ or various organs can be sampled simultaneously. The technology allows assessment of organ function by biochemical profiling, determination of potential biomarkers, and drug monitoring. The use of this method for preintervention analysis could enhance the decision-making process for the best possible personalized approach, whereas post-transplantation monitoring would be used for graft assessments and fast response in case of organ failure.

Court decisions on medical malpractice.

BACKGROUND: Recent studies on court cases dealing with medical malpractice are few and far between. This retrospective study, therefore, undertakes an analysis of medical malpractice lawsuits brought before regional courts in two judicial districts of the federal state of Hesse. METHODS: Over a 5-year period (2006-2010), 232 court decisions on medical malpractice taken by the regional courts (Landgericht) of Kassel and Marburg were evaluated according to medical discipline, diagnosis, therapy, relevant level of care, charge of neglect of duty by the claimant party, outcome of the lawsuit, and further criteria. RESULTS: With certain overlaps, the disciplines most frequently confronted with claims of medical malpractice were accident surgery and orthopedics (30.2%; n = 70), dentistry (16.4%; n = 38), surgery (12.1%; n = 28), and gynecology and obstetrics (7.8%; n = 18), followed by the remaining medical disciplines (38.8%; n = 90). Malpractice allegations were brought against the practice-based sector in 35.8 % (n = 83) of cases, the hospital-based sector in 63.3% (n = 147) of cases, and other sectors in 0.9% (n = 2) of cases. The allegation grounds included false administration of treatment (67.2%; n = 156), false indication of treatment (37.1%; n = 86), false diagnosis (31.5%; n = 73), and/or organizational negligence (13.8%; n = 32). A breach of duty to inform was given as grounds for the claim in 38.8% (n = 90) of cases. A significant majority of 65.6% (n = 152) of cases ended in a court settlement. Of the cases, 18.9% (n = 44) were concluded by claim withdrawal, 11.2% (n = 26) by claim dismissal and 2.6% (n = 6) by criminal sentence. Of the cases, 1.7% (n = 4) were for purposes of securing evidence. CONCLUSION: Although there was no conclusive evidence of malpractice, two thirds of the cases ended in a court settlement. On the one hand, this outcome reduces the burden on the courts, but on the other, it can in the long term give rise to expectations that doctors will accept liability even in cases of inevitable deterioration following due and proper treatment.

Solid phase microextraction fills the gap in tissue sampling protocols.

Metabolomics and biomarkers discovery are an integral part of bioanalysis. However, untargeted tissue analysis remains as the bottleneck of such studies due to the invasiveness of sample collection, as well as the laborious and time-consuming sample preparation protocols. In the current study, technology integrating in vivo sampling, sample preparation and global extraction of metabolites--solid phase microextraction was presented and evaluated during liver and lung transplantation in pig model. Sampling approaches, including selection of the probe, transportation, storage conditions and analyte coverage were discussed. The applicability of the method for metabolomics studies was demonstrated during lung transplantation experiments.