Technique of Subnormothermic <em>Ex Vivo</em> 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 ...

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 ...

Normothermic <em>Ex Vivo</em> Kidney Perfusion for the Preservation of Kidney Grafts prior to Transplantation

Kidney transplantation has become a well-established treatment option for patients with end-stage renal failure. The persisting organ shortage remains a ...

Toronto General Hospital

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.

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

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.

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

Pancreas-kidney transplantation with enteric drainage has become a standard treatment in diabetic patients with renal failure. Leaks of the graft duodenum (DL) remain a significant complication after transplantation. We studied incidence and predisposing factors of DLs in both simultaneous pancreas-kidney (SPK) and pancreas after kidney (PAK) transplantation. Between January 2002 and April 2013, 284 pancreas transplantations were performed including 191 SPK (67.3%) and 93 PAK (32.7%). Patient data were analyzed for occurrence of DLs, risk factors, leak etiology, and graft survival. Of 18 DLs (incidence 6.3%), 12 (67%) occurred within the first 100 days after transplantation. Six grafts (33%) were rescued by duodenal segment resection. Risk factors for a DL were PAK transplantation sequence (odds ratio 3.526, P = 0.008) and preoperative immunosuppression (odds ratio 3.328, P = 0.012). In the SPK subgroup, postoperative peak amylase as marker of preservation/reperfusion injury and recipient pretransplantation cardiovascular interventions as marker of atherosclerosis severity were associated with an increased incidence of DLs. CMV-mismatch constellations showed an increased incidence in the SPK subgroup, however without significance probability. Long-term immunosuppression in PAK transplantation is a major risk factor for DLs. Early surgical revision offers the chance of graft rescue.

Vinzent N. Spetzler

Multi Organ Transplant Program,
Department of Surgery,
Multi Organ Transplant Program, Department of Surgery

Toronto General Hospital

Technique of Subnormothermic Ex Vivo Liver Perfusion for the Storage, Assessment, and Repair of Marginal Liver Grafts

Technique of Porcine Liver Procurement and Orthotopic Transplantation using an Active Porto-Caval Shunt

Normothermic Ex Vivo Kidney Perfusion for the Preservation of Kidney Grafts prior to Transplantation

Vinzent N. Spetzler

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Multi Organ Transplant Program,Department of Surgery,Multi Organ Transplant Program, Department of Surgery

Toronto General Hospital

Technique of Subnormothermic Ex Vivo Liver Perfusion for the Storage, Assessment, and Repair of Marginal Liver Grafts

Technique of Porcine Liver Procurement and Orthotopic Transplantation using an Active Porto-Caval Shunt

Normothermic Ex Vivo Kidney Perfusion for the Preservation of Kidney Grafts prior to Transplantation

Multi Organ Transplant Program,
Department of Surgery,
Multi Organ Transplant Program, Department of Surgery