ABSTRACT
The liver and spleen are major biological barriers to translating nanomedicines because they sequester the majority of administered nanomaterials and prevent delivery to diseased tissue. Here we examined the blood clearance mechanism of administered hard nanomaterials in relation to blood flow dynamics, organ microarchitecture and cellular phenotype. We found that nanomaterial velocity reduces 1,000-fold as they enter and traverse the liver, leading to 7.5 times more nanomaterial interaction with hepatic cells relative to peripheral cells. In the liver, Kupffer cells (84.8 ± 6.4%), hepatic B cells (81.5 ± 9.3%) and liver sinusoidal endothelial cells (64.6 ± 13.7%) interacted with administered PEGylated quantum dots, but splenic macrophages took up less material (25.4 ± 10.1%) due to differences in phenotype. The uptake patterns were similar for two other nanomaterial types and five different surface chemistries. Potential new strategies to overcome off-target nanomaterial accumulation may involve manipulating intra-organ flow dynamics and modulating the cellular phenotype to alter hepatic cell interactions.
Subject(s)
Liver/metabolism , Nanostructures , Hardness , Liver/cytology , Phenotype , Surface PropertiesABSTRACT
OBJECTIVE: To compare the outcome of adult live donor liver transplantation (LDLT) with grafts from older versus younger donors. INTRODUCTION: Using older donor grafts for adult LDLT may help expand the donor pool. However, the risks of LDLT with older donors remain controversial, and many centers are reluctant to use live donors aged 45 years or older for adult LDLT. METHODS: Outcomes of patients receiving a LDLT graft from donors aged 50 years or older (nâ=â91) were compared with those receiving a live donor graft from donors younger than 50 years (nâ=â378). RESULTS: Incidences of biliary (LDLT <50: 24% vs LDLT ≥50: 23%; Pâ=â0.89) and major complications (LDLT <50: 24% vs LDLT ≥50: 24%; Pâ=â1) were similar between both groups of recipients. No difference was observed in 30-day recipient mortality (LDLT <50: 3% vs LDLT ≥50: 0%; Pâ=â0.13). The 1- (90% vs 90%), 5- (82% vs 73%), and 10- (71% vs 58%) year graft survival was statistically similar between both groups (Pâ=â0.075). Likewise, patient survival after 1- (92% vs 96%), 5- (83% vs 79%), and 10- (76% vs 69%) years was also similar (Pâ=â0.686). Overall, donors rate of major complications (Dindo-Clavien ≥3b) within 30 days was low (nâ=â2.3%) and not different in older versus younger donors (Pâ=â1). Donor median hospital stay in both groups was identical [LDLT <50: 6 (4-17) vs LDLT ≥50: 6 (4-14) days; Pâ=â0.65]. No donor death occurred and all donors had full recovery and returned to baseline activity. CONCLUSIONS: Right lobe LDLT with donors aged 50 years or older results in acceptable recipient outcome without increased donor morbidity or mortality. Potential live donors should not be declined on the basis of age alone.
Subject(s)
Liver Transplantation , Living Donors , Adolescent , Adult , Age Factors , Biomarkers/analysis , Female , Graft Survival , Humans , Length of Stay/statistics & numerical data , Liver Transplantation/mortality , Male , Middle Aged , Postoperative Complications/mortality , Prospective Studies , Treatment OutcomeABSTRACT
We developed a novel technique of subnormothermic ex vivo liver perfusion (SNEVLP) for the storage of liver grafts before transplantation. To test the safety of SNEVLP for the nonextended criteria grafts (standard grafts), we compared it to a control group with minimal cold static storage (CS) time. Heart-beating pig liver retrieval was performed. Grafts were either stored in cold unmodified University of Wisconsin solution (CS-1), in cold University of Wisconsin solution with ex vivo perfusion additives (CS-2), or preserved with a sequence of 3 hours CS and 3 hours SNEVLP (33°C), followed by orthotopic liver transplantation. Liver function tests and histology were investigated. Aspartate aminotransferase (AST) levels during SNEVLP remained stable (54.3 ± 12.6 U/L at 1 hour to 47.0 ± 31.9 U/L at 3 hours). Posttransplantation, SNEVLP versus CS-1 livers had decreased AST levels (peak at day 1, 1081.9 ± 788.5 versus 1546.7 ± 509.3 U/L; P = 0.14; at day 2, 316.7 ± 188.1 versus 948.2 ± 740.9 U/L; P = 0.04) and alkaline phosphatase levels (peak at day 1, 150.4 ± 19.3 versus 203.7 ± 33.6 U/L; P = 0.003). Bilirubin levels were constantly within the physiological range in the SNEVLP group, whereas the CS-1 group presented a large standard deviation, including pathologically increased values. Hyaluronic acid as a marker of endothelial cell (EC) function was markedly improved by SNEVLP during the early posttransplant phase (5 hours posttransplant, 1172.75 ± 598.5 versus 5540.5 ± 2755.4 ng/mL). Peak international normalized ratio was similar between SNEVLP and CS-1 groups after transplantation. Immunohistochemistry for cleaved caspase 3 demonstrated more apoptotic sinusoidal cells in the CS-1 group when compared to SNEVLP grafts 2 hours after reperfusion (19.4 ± 19.5 versus 133.2 ± 48.8 cells/high-power field; P = 0.002). Adding normothermic CS-2 had no impact on liver injury or function after transplantation when compared to CS-1. In conclusion, SNEVLP is safe to use for standard donor grafts and is associated with improved EC and bile duct injury even in grafts with minimal CS time.
Subject(s)
Liver Transplantation , Organ Preservation/methods , Perfusion , Animals , Bile Ducts/physiology , Endothelial Cells/physiology , Liver Function Tests , Male , Swine , Transplants/physiologyABSTRACT
Normothermic ex vivo liver perfusion (NEVLP) improves graft preservation by avoiding cold ischemia injury. We investigated whether the protective effects of NEVLP can be further improved by applying strategies targeted on reducing the activation of proinflammatory cytokines during perfusion. Livers retrieved under heart-beating conditions were perfused for 4 hours. Following the preservation period, a pig liver transplantation was performed. In group 1 (n = 5), anti-inflammatory strategies (alprostadil, n-acetylcysteine, carbon monoxide, sevoflurane, and subnormothermic temperature [33°C]) were applied. This was compared with a perfused control group (group 2) where livers (n = 5) were perfused at 37°C without anti-inflammatory agents, similar to the setup used in current European clinical trials, and to a control group preserved with static cold storage (group 3). During 3-day follow-up, markers of reperfusion injury, bile duct injury, and liver function were examined. Aspartate aminotransferase (AST) levels during perfusion were significantly lower in the study versus control group at 1 hour (52 ± 6 versus 162 ± 86 U/L; P = 0.01), 2 hours (43 ± 5 versus 191 ± 111 U/L; P = 0.008), and 3 hours (24 ± 16 versus 218 ± 121 U/L; P = 0.009). During perfusion, group 1 versus group 2 had reduced interleukin (IL) 6, tumor necrosis factor α, and galactosidase levels and increased IL10 levels. After transplantation, group 1 had lower AST peak levels compared with group 2 and group 3 (1400 ± 653 versus 2097 ± 1071 versus 1747 ± 842 U/L; P = 0.47) without reaching significance. Bilirubin levels were significantly lower in group 1 versus group 2 at day 1 (3.6 ± 1.5 versus 6.60 ± 1.5 µmol/L; P = 0.02) and 3 (2 ± 1.1 versus 9.7 ± 7.6 µmol/L; P = 0.01). A trend toward decreased hyaluronic acid, as a marker of improved endothelial cell function, was observed at 1, 3, and 5 hours after reperfusion in group 1 versus group 2. Only 1 early death occurred in each group (80% survival). In conclusion, addition of anti-inflammatory strategies further improves warm perfused preservation. Liver Transplantation 22 1573-1583 2016 AASLD.
Subject(s)
Allografts/metabolism , Anti-Inflammatory Agents/therapeutic use , Liver Transplantation , Liver/metabolism , Organ Preservation/methods , Perfusion/methods , Tissue and Organ Harvesting/methods , Acetylcysteine/therapeutic use , Alprostadil/therapeutic use , Animals , Aspartate Aminotransferases/metabolism , Biliary Tract/pathology , Bilirubin/analysis , Cold Ischemia/adverse effects , Cytokines/metabolism , Endothelial Cells/metabolism , Hyaluronic Acid/metabolism , Inflammation Mediators/metabolism , Liver/pathology , Male , Methyl Ethers/therapeutic use , Models, Animal , Reperfusion Injury/etiology , Reperfusion Injury/pathology , Reperfusion Injury/prevention & control , Sevoflurane , Sus scrofa , Swine , TemperatureABSTRACT
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.
Subject(s)
End Stage Liver Disease/surgery , Liver Transplantation/mortality , Adult , Humans , Intensive Care Units , Intubation, Intratracheal , Middle Aged , Ontario/epidemiology , Risk FactorsABSTRACT
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.
Subject(s)
Anastomotic Leak/physiopathology , Duodenum/physiopathology , Pancreas Transplantation/adverse effects , Pancreas Transplantation/methods , Adult , Cytomegalovirus Infections/prevention & control , Databases, Factual , Diabetes Complications/surgery , Diabetes Mellitus/surgery , Drainage , Female , Graft Rejection/epidemiology , Graft Survival , Humans , Immunosuppression Therapy , Kidney Transplantation/methods , Male , Middle Aged , Multivariate Analysis , Postoperative Complications , Reoperation , Reperfusion Injury , Retrospective Studies , Risk Factors , Treatment Outcome , Young AdultABSTRACT
Heme Oxygenase-1 and its product biliverdin/bilirubin have been demonstrated to protect against ischemia/reperfusion injury (IRI). We investigated whether increased preoperative bilirubin values of transplant recipients decrease IRI. Preoperative bilirubin levels of live donor liver recipients were correlated to postoperative liver transaminase as a marker of IRI. Additionally, two recipient groups with pretransplant bilirubin levels >24 µmol/l (n = 348) and ≤24 µmol/l (n = 118) were compared. Post-transplant liver function, complications, length of hospital stay, and patient and graft survival were assessed. Preoperative bilirubin levels were negatively correlated to the postoperative increase in transaminases suggesting a protective effect against IRI. The maximal rise of ALT after transplantation in high versus low bilirubin patients was 288 (-210-2457) U/l vs. 375 (-11-2102) U/l, P = 0.006. Bilirubin remained a significant determining factor in a multivariate linear regression analysis. The MELD score and its individual components as a marker of severity of chronic liver disease were significantly higher in the high versus low bilirubin group (P < 0.001). Despite this, overall complication rate (21.0% vs. 21.2%, P = 0.88), hospital stay [13 (4-260) vs. 14 (6-313) days, P = 0.93), and 1-year graft survival (90.8% vs. 89.0%, P = 0.62) were similar in both groups. High bilirubin levels of liver recipients before live donor transplantation is associated with decreased postoperative IRI.
Subject(s)
Bilirubin/blood , Liver Diseases/surgery , Liver Transplantation/adverse effects , Living Donors , Reperfusion Injury/blood , Adolescent , Adult , Aged , Body Mass Index , Cholangitis, Sclerosing/blood , Cholangitis, Sclerosing/surgery , Female , Graft Survival , Heme Oxygenase-1/metabolism , Humans , Liver Cirrhosis, Biliary/blood , Liver Cirrhosis, Biliary/surgery , Male , Middle Aged , Multivariate Analysis , Postoperative Period , Research Design , Retrospective Studies , Tissue and Organ Procurement , Treatment Outcome , Young AdultABSTRACT
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.
Subject(s)
Biomarkers/analysis , Monitoring, Physiologic/methods , Pharmaceutical Preparations/analysis , Solid Phase Microextraction , Animals , Biomarkers/metabolism , Intraoperative Period , Male , Pharmaceutical Preparations/metabolism , SwineABSTRACT
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.
Subject(s)
Liver Transplantation , Liver/pathology , Organ Preservation/methods , Reperfusion Injury/prevention & control , Animals , Bile Ducts/pathology , Endothelial Cells , Erythrocytes , Hepatocytes , Liver Function Tests , Male , Perfusion , SwineABSTRACT
This combined anatomic and clinical study illustrates the first experiences of an osteomyocutaneous flap from the medial femoral condyle for reconstruction of composite tissue defects. We analyzed the anatomic consistency and the vascular distribution of this flap and showed that muscle tissue can easily be added as a composite flap. Twenty-one flaps were harvested from fresh adult cadavers with careful identification of the origin and the course of the three different branches of the descending genicular artery. The corresponding skin areas and muscle portion were identified. The clinical application of this flap was described for closure of complex calcaneal defects. The cadaveric study presented a constant pedicle length and diameter of the arteries, combined with a constant venous drainage. Furthermore, the medial condyle provided a corticocancellous segment and separate vascularity for skin and muscle portions. In the case reports, satisfying results of bone union and soft tissue contouring were achieved. The medial femur condyle region is a reliable donor site for composite flaps, providing a good corticocancellous bony structure and a separate skin paddle, as well as a muscle portion. Its vascular distribution shows anatomic consistency. Despite long-term atrophy of muscle transplants, we believe the additional muscle tissue improves the reconstruction results and provides better soft tissue contouring.
Subject(s)
Bone Transplantation/methods , Calcaneus/surgery , Epiphyses/transplantation , Free Tissue Flaps/blood supply , Plastic Surgery Procedures/methods , Adult , Aged , Cadaver , Calcaneus/injuries , Dissection , Epiphyses/surgery , Female , Femur/surgery , Follow-Up Studies , Fracture Fixation/methods , Fractures, Bone/surgery , Humans , Injury Severity Score , Knee Joint/anatomy & histology , Knee Joint/blood supply , Male , Middle Aged , Muscle, Skeletal/surgery , Risk Assessment , Skin Transplantation/methods , Soft Tissue Injuries/diagnosis , Soft Tissue Injuries/surgery , Tissue and Organ Harvesting , Treatment OutcomeABSTRACT
BACKGROUND: Bile leaks are one of the most common complications after liver resection. The International Study Group of Liver Surgery (ISGLS) established a uniform bile leak definition including a severity grading. However, a risk factor assessment according to ISGLS grading as well as the clinical implications has not been studied sufficiently so far. METHODS: The incidence and grading of bile leaks according to ISGLS were prospectively documented in 501 consecutive liver resections between July 2012 and December 2016. A multivariate regression analysis was performed for risk factor assessment. Association with other surgical complications, 90-day mortality as well as length of hospital stay (LOS) was studied. RESULTS: The total rate of bile leaks in this cohort was 14.0%: 2.8% grade A, 8.0% grade B, and 3.2% grade C bile leaks were observed. Preoperative chemotherapy or biliary intervention, diagnosis of hilar cholangiocarcinoma, colorectal metastasis, central minor liver resection, major hepatectomy, extended hepatectomy or two-stage hepatectomy, were some of the risk factors leading to bile leaks. The multivariate regression analysis revealed that preoperative chemotherapy, major hepatectomy and biliodigestive reconstruction remained significant independent risk factors for bile leaks. Grade C bile leaks were associated not only with surgical site infection, but also with an increased 90-day mortality and prolonged LOS. CONCLUSIONS: The preoperative treatment as well as the surgical procedure had significant influence on the incidence and the severity of bile leaks. Grade C bile leaks were clinically most relevant, and led to significant increased LOS, rate of infection, and mortality.
ABSTRACT
BACKGROUND: The cytoprotective effects of hemeoxygenase-1 and its product biliverdin/bilirubin are widely acknowledged in experimental transplant medicine. However, its potentially beneficial effect during organ reperfusion is not established. METHODS: In a matched study, we compared markers of reperfusion injury (alanine aminotransferase/aspartate aminotransferase) and transplantation outcome (complication rates, liver function, and survival) between recipient groups with "normal" versus "increased" preoperative bilirubin values. Groups were matched for donor and recipient age, liver disease, year of transplantation, and recipient's preoperative condition (modified model for end-stage liver disease score excluding bilirubin). RESULTS: The postoperative transaminase peak was significantly higher when comparing the "normal" to the "increased" bilirubin group (maximum aspartate aminotransferase "normal" 2013 [325-13 210] U/L vs "increased" 1360 [221-15 460] U/L, P = 0.006; maximum alanine aminotransferase "normal" 1151 [82-6595] U/L vs "increased" 820 [66-5382] U/L, P = 0.01). Grafts in the "increased" bilirubin group had faster recovery of graft function with faster decrease in international normalized ratio at days 3 and 7 posttransplantation in the "increased" vs "normal" bilirubin group. Although long-term functional parameters (international normalized ratio and bilirubin posttransplantation) as well as surgical and biliary complication rates were similar in both groups, 1-year survival rates were significantly higher in the group with increased preoperative bilirubin (graft survival, "normal" 86% vs "increased" 97%; P = 0.006). CONCLUSIONS: Increased bilirubin levels of liver graft recipients before transplantation are associated with reduced reperfusion injury and improved survival after transplantation.
ABSTRACT
BACKGROUND: Duodenal leak remains a major cause of morbidity and graft loss in pancreas transplant recipients. The role and efficacy of surgical and image-guided interventions to salvage enterically drained grafts with a duodenal leak has yet to be defined. METHODS: We investigated the incidence, treatment, and outcome of duodenal leak in 426 pancreas transplantation recipients from 2000 to 2015. RESULTS: Duodenal leak developed in 33 (7.8%) recipients after a median follow-up of 5.3 (range, 0.5-15.2) years. Most leaks occurred during the first year (n = 22; 67%), and most were located near the proximal and distal duodenal staple line. Graft pancreatectomy was performed in 8 patients as primary therapy because of unfavorable local and/or systemic conditions. Salvage was attempted in 25 patients using percutaneous drainage (n = 4), surgical drainage (n = 4), or surgical repair (n = 17). Percutaneous or surgical drainage failed to control the leak in 7 of these 8 patients, and all 7 ultimately required graft pancreatectomy for persistent leak and sepsis. Surgical repair salvaged 14 grafts, and 13 grafts continue to function after a median follow-up of 2.9 (range, 1.1-6.3) years after repair. CONCLUSIONS: Our study shows that in selected patients a duodenal leak can be repaired successfully and safely in enterically drained grafts.
ABSTRACT
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.
Subject(s)
Liver Transplantation/methods , Portacaval Shunt, Surgical/methods , Animals , Graft Survival , Male , Models, Animal , SwineABSTRACT
Kidney transplantation has become a well-established treatment option for patients with end-stage renal failure. The persisting organ shortage remains a serious problem. Therefore, the acceptance criteria for organ donors have been extended leading to the usage of marginal kidney grafts. These marginal organs tolerate cold storage poorly resulting in increased preservation injury and higher rates of delayed graft function. To overcome the limitations of cold storage, extensive research is focused on alternative normothermic preservation methods. Ex vivo normothermic organ perfusion is an innovative preservation technique. The first experimental and clinical trials for ex vivo lung, liver, and kidney perfusions demonstrated favorable outcomes. In addition to the reduction of cold ischemic injury, the method of normothermic kidney storage offers the opportunity for organ assessment and repair. This manuscript provides information about kidney retrieval, organ preservation techniques, and isolated ex vivo normothermic kidney perfusion (NEVKP) in a porcine model. Surgical techniques, set up for the perfusion solution and the circuit, potential assessment options, and representative results are demonstrated.
Subject(s)
Kidney Transplantation/methods , Kidney , Organ Preservation/methods , Animals , Male , Models, Animal , Perfusion/methods , SwineABSTRACT
UNLABELLED: Patients with acute and chronic liver disease often require admission to intensive care unit (ICU) and mechanical ventilation support before liver transplantation (LT). Rapid disease progression and high mortality on LT waiting lists makes live donor LT (LDLT) an attractive option for this patient population. METHODS: During 2000 to 2011, all ICU-bound and mechanically ventilated patients receiving an LDLT (n = 7) were compared to patients receiving a deceased donor LT (DDLT) (n = 38). RESULTS: Both groups were comparable regarding length of pretransplant ICU stay (DDLT: 2 [1-31] days vs LDLT: 2 [1-8] days; P = 0.2), days under mechanical ventilation (DDLT: 2 [1-31] days vs LDLT: 2 [1-5] days; P = 0.2), pretransplant dialysis (DDLT: 45% vs LDLT: 43%; P = 1) and model for end-stage liver disease score (DDLT: 33 ± 8 vs LDLT: 33 ± 10; P = 0.911). Live donors median evaluation time was 24 hours (18-561 hours). As expected, median time on waiting list was significantly lower in the LDLT group (DDLT: 13 [0-1704] days vs LDLT: 10 [1-33] days; P = 0.008). Incidence of postoperative complications was numerically, albeit not significantly higher in the DDLT versus LDLT (68% vs 29%; P = 0.08). No difference was detected between LDLT and DDLT patients regarding 1-year (DDLT: 76% vs LDLT: 85%), 3-year (DDLT: 68% vs LDLT: 85%), and 5-year (DDLT: 68% vs LDLT: 85%) graft and patient survivals (P = 0.41). No severe donor complication occurred after live donation. CONCLUSIONS: The LDLT may provide a faster access to transplantation and therefore, offers an alternative treatment option for critically ill patients requiring ICU care and mechanical ventilation support at the time of transplantation.
ABSTRACT
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.
Subject(s)
Liver Transplantation/methods , Liver , Organ Preservation/methods , Perfusion/methods , Animals , Cold Temperature , Male , Models, Animal , Swine , Tissue DonorsABSTRACT
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.