Teresa Diago Uso

Use of tissue plasminogen activator in liver transplantation from donation after cardiac death donors.

Ischemic‐type biliary stricture (ITBS) occurs in up to 50% after liver transplantation (LT) from donation after cardiac death (DCD) donors. Thrombus formation in the peribiliary microcirculation is a postulated mechanism. The aim was to describe our experience of tissue plasminogen activator (TPA) administration in DCD‐LT. TPA was injected into the donor hepatic artery on the backtable (n = 22). Two recipients developed ITBS including one graft failure. Although excessive postreperfusion bleeding was seen in 14 recipients, the amount of TPA was comparable between those with and without excessive bleeding (6.4 ± 2.8 vs. 6.6 ± 2.8 mg, p = 0.78). However, donor age (41 ± 12 vs. 29 ± 9 years, p = 0.02), donor BMI (26.3 ± 5.5 vs. 21.7 ± 3.6 kg/m2, p = 0.03), previous laparotomy (50% vs. 0%, p = 0.02) and lactate after portal reperfusion (6.3 ± 4.6 vs. 2.8 ± 0.9 mmol/L, p = 0.005) were significantly greater in recipients with excessive bleeding. In conclusion, the use of TPA may lower the risk of ITBS‐related graft failure in DCD‐LT. Excessive bleeding may be related to poor graft quality and previous laparotomy rather than the amount of TPA. Further studies are needed in larger population.

Sanguineous normothermic machine perfusion improves hemodynamics and biliary epithelial regeneration in donation after cardiac death porcine livers

The effects of normothermic machine perfusion (NMP) on the postreperfusion hemodynamics and extrahepatic biliary duct histology of donation after cardiac death (DCD) livers after transplantation have not been addressed thoroughly and represent the objective of this study. Ten livers (5 per group) with 60 minutes of warm ischemia were preserved via cold storage (CS) or sanguineous NMP for 10 hours, and then they were reperfused for 24 hours with whole blood in an isolated perfusion system to simulate transplantation. In our experiment, the arterial and portal vein flows were stable in the NMP group during the entire reperfusion simulation, whereas they decreased dramatically in the CS group after 16 hours of reperfusion (P < 0.05); these findings were consistent with severe parenchymal injury. Similarly, significant differences existed between the CS and NMP groups with respect to the release of hepatocellular enzymes, the volume of bile produced, and the levels of enzymes released into bile (P < 0.05). According to histology, CS livers presented with diffuse hepatocyte congestion, necrosis, intraparenchymal hemorrhaging, denudated biliary epithelium, and submucosal bile duct necrosis, whereas NMP livers showed very mild injury to the liver parenchyma and biliary architecture. Most importantly, Ki‐67 staining in extrahepatic bile ducts showed biliary epithelial regeneration. In conclusion, our findings advance the knowledge of the postreperfusion events that characterize DCD livers and suggest NMP as a beneficial preservation modality that is able to improve biliary regeneration after a major ischemic event and may prevent the development of ischemic cholangiopathy in the setting of clinical transplantation. Liver Transpl 20:987–999, 2014.

Mortality of Intra-Abdominal Desmoid Tumors in Patients With Familial Adenomatous Polyposis A Single Center Review of 154 Patients

Introduction:Intra-abdominal desmoid tumors are one of the leading causes of death in patients with familial adenomatous polyposis. Their behavior is unpredictable and their biology is poorly understood, accounting for the lack of a standardized medical and surgical approach. The aim of this study was to evaluate the mortality rate of patients with intra-abdominal desmoid tumors and to identify prognostic factors for the evolution of the disease. Materials and Methods:A total of 154 patients with intra-abdominal desmoid tumors were included in the study. Each tumor was staged and each patient was categorized according to the stage of their most advanced tumor. Mortality was analyzed and the univariate risk factors associated with survival were included in a multivariable Cox regression model. A scoring system was derived from the multivariate analysis to refine outcomes within stages. Results:Five-year survival of patients with stage I, II, III, and IV intra-abdominal desmoid tumor were 95%, 100%, 89%, and 76% respectively (P < 0.001). Severe pain/narcotic dependency, tumor size larger than 10 cm, and need for total parenteral nutrition were shown to further define survival within stages. Five-year survival rate of stage IV patient with all of the above-mentioned risk factors was only 53%. Conclusions:Our study confirmed the validity of the staging system to predict mortality in patients with intra-abdominal desmoid tumors and identified additional risk factors able to better define the risk of death within each stage. Risk stratification is crucial in directing patients with advanced disease and poor prognosis to the most appropriate medical and surgical options.

Ex Vivo Normothermic Machine Perfusion Is Safe, Simple, and Reliable: Results From a Large Animal Model

Introduction. Normothermic machine perfusion (NMP) is an emerging preservation modality that holds the potential to prevent the injury associated with low temperature and to promote organ repair that follows ischemic cell damage. While several animal studies have showed its superiority over cold storage (CS), minimal studies in the literature have focused on safety, feasibility, and reliability of this technology, which represent key factors in its implementation into clinical practice. The aim of the present study is to report safety and performance data on NMP of DCD porcine livers. Materials and Methods. After 60 minutes of warm ischemia time, 20 pig livers were preserved using either NMP (n = 15; physiologic perfusion temperature) or CS group (n = 5) for a preservation time of 10 hours. Livers were then tested on a transplant simulation model for 24 hours. Machine safety was assessed by measuring system failure events, the ability to monitor perfusion parameters, sterility, and vessel integrity. The ability of the machine to preserve injured organs was assessed by liver function tests, hemodynamic parameters, and histology. Results. No system failures were recorded. Target hemodynamic parameters were easily achieved and vascular complications were not encountered. Liver function parameters as well as histology showed significant differences between the 2 groups, with NMP livers showing preserved liver function and histological architecture, while CS livers presenting postreperfusion parameters consistent with unrecoverable cell injury. Conclusion. Our study shows that NMP is safe, reliable, and provides superior graft preservation compared to CS in our DCD porcine model.

Is there an advantage of living over deceased donation in liver transplantation

Living donor liver transplantation (LDLT) is a well‐established strategy to decrease the mortality in the waiting list and recent studies have demonstrated its value even in patients with low MELD score. However, LDLT is still under a high level of scrutiny because of its technical complexity and ethical challenges as demonstrated by a decline in the number of procedures performed in the last decade in Western Countries. Many aspects make LDLT different from deceased donor liver transplantation, including timing of transplantation, procedure‐related complications as well as immunological factors that may affect graft outcomes. Our review suggests that in selected cases, LDLT offers significant advantages over deceased donor liver transplantation and should be used more liberally.

Comparing Normothermic Machine Perfusion Preservation With Different Perfusates on Porcine Livers From Donors After Circulatory Death.

The utilization of normothermic machine perfusion (NMP) may be an effective strategy to resuscitate livers from donation after circulatory death (DCD). There is no consensus regarding the efficacy of different perfusates on graft and bile duct viability. The aim of this study was to compare, in an NMP porcine DCD model, the preservation potential of three different perfusates. Twenty porcine livers with 60 min of warm ischemia were separated into four preservation groups: cold storage (CS), NMP with Steen solution (Steen; XVIVO Perfusion Inc., Denver, CO), Steen plus red blood cells (RBCs), or whole blood (WB). All livers were preserved for 10 h and reperfused to simulate transplantation for 24 h. During preservation, the NMP with Steen group presented the highest hepatocellular injury. At reperfusion, the CS group had the lowest bile production and the worst hepatocellular injury compared with all other groups, followed by NMP with Steen; the Steen plus RBC and WB groups presented the best functional and hepatocellular injury outcomes, with WB livers showing lower aspartate aminotransferase release and a trend toward better results for most parameters. Based on our results, a perfusate that contains an oxygen carrier is most effective in a model of NMP porcine DCD livers compared with Steen solution. Specifically, WB‐perfused livers showed a trend toward better outcomes compared with Steen plus RBCs.

Side‐to‐side cavocavostomy with an endovascular stapler: Rescue technique for severe hepatic vein and/or inferior vena cava outflow obstruction after liver transplantation using the piggyback technique

Venous outflow obstruction is a rare but potentially lethal complication after orthotopic liver transplantation (OLT) with the “piggyback” technique. Therapeutic options include angioplasty with or without stent placement, surgical reconstruction of the venous anastomosis, and retransplantation. Surgical options are technically very challenging and the outcomes discouraging. We describe here two cases of venous outflow obstruction in recipients of piggyback liver grafts, one involving both the vena cava and hepatic veins and the other affecting only hepatic vein outflow. Both patients were treated successfully with side‐to‐side cavo‐cavostomy using an endovascular (endo‐GIA) stapler. This novel technique is fast and effective in resolving the outflow obstruction. Liver Transpl 15:49–53, 2009.

Is impaired hepatic arterial buffer response a risk factor for biliary anastomotic stricture in liver transplant recipients

BACKGROUND Blood flow to the liver is partly maintained by the hepatic arterial buffer response (HABR), which is an intrinsic autoregulatory mechanism. Temporary clamping of the portal vein (PV) results in augmentation in hepatic artery flow (augHAF). Portal hyperperfusion impairs HAF due to the HABR in liver transplantation (LT). The aim of this study is to examine the effect of the HABR on biliary anastomotic stricture (BAS). METHODS In 234 cadaveric whole LTs, PV flow (PVF), basal HAF, and augHAF were measured intra-operatively after allograft implantation. All recipients with a vascular complication were excluded. Buffer capacity (BC) was calculated as (augHAF - basal HAF)/PVF to quantify the HABR. Recipients were divided into 2 groups based on their BC: low BC (<0.074; n = 117) or high BC (> or =0.074; n = 117). RESULTS Of the 234 recipients, 23 (9.8%) had early BAS (< or =60 days after LT) and 18 (7.7%) had late BAS (>60 days after LT). The incidence of late BAS and bile leakage was similar between the groups; however, the incidence of early BAS in the low BC group was greater than that in the high BC group (15% vs 5.1%; P = .0168). In the multivariate analysis, low BC (P = .0325) and bile leakage (P = .0002) were found to be independent risk factors affecting early BAS. CONCLUSION Recipients with low BC who may have impaired HABR are at greater risk of early BAS after LT. Intraoperative measurements of blood flow help predict the risk of BAS.

Impact of Temperature on Porcine Liver Machine Perfusion From Donors After Cardiac Death.

Normothermic machine perfusion (NMP) has been introduced as a promising technology to preserve and possibly repair marginal liver grafts. The aim of this study was to compare the effect of temperature on the preservation of donation after cardiac death (DCD) liver grafts in an ex vivo perfusion model after NMP (38.5°C) and subnormothermic machine perfusion (SNMP, 21°C) with a control group preserved by cold storage (CS, 4°C). Fifteen porcine livers with 60 min of warm ischemia were preserved for 10 h by NMP, SNMP or CS (n = 5/group). After the preservation phase all livers were reperfused for 24 h in an isolated perfusion system with whole blood at 38.5°C to simulate transplantation. At the end of transplant simulation, the NMP group showed significantly lower hepatocellular enzyme level (AST: 277 ± 69 U/L; ALT: 22 ± 2 U/L; P < 0.03) compared to both SNMP (AST: 3243 ± 1048 U/L; ALT: 127 ± 70 U/L) and CS (AST: 3150 ± 1546 U/L; ALT: 185 ± 97 U/L). There was no significant difference between SNMP and CS. Bile production was significantly higher in the NMP group (219 ± 43 mL; P < 0.01) compared to both SNMP (49 ± 84 mL) and CS (12 ± 16 mL) with no significant difference between the latter two groups. Histologically, the NMP livers showed preserved cellular architecture compared to the SNMP and CS groups. NMP was able to recover DCD livers showing superior hepatocellular integrity, biliary function, and microcirculation compared to SNMP and CS. SNMP showed some significant benefit over CS, yet has not shown any advantage over NMP.

Preparing for the inevitable: The death of a living liver donor: Death of a Living Liver Donor

Living donor liver transplantation (LDLT) is associated with a low but finite and well‐documented risk of donor morbidity and mortality, so organizations and individuals involved in this activity must accept the fact that a donor death is a question of when and not if. Studies in the field of crisis management show that preparing for the inevitable not only is critical in preparing institutions to better respond to catastrophic events but more importantly plays a crucial role in preventing them. This article describes the background of crisis management with specific reference to the death of a living liver donor and proposes a general framework that can be adopted by LDLT programs around the world. Liver Transpl 19:656–660, 2013.