The Survival Paradox of Elderly Patients After Major Liver Resections

The objective of this study is to assess the outcome of liver resections in the elderly in a matched control analysis. From a prospective single center database of 628 patients, 132 patients were aged 60 years or over and underwent a primary major liver resection. Of these patients, 93 could be matched one-to-one with a control patient, aged less than 60 years, with the same diagnosis and the same type of liver resection. The mean age difference was 16.7 years. Patients over 60 years of age had a significantly higher American Society of Anaesthesiologists (ASA) grade. All other demographics and operative characteristics were not different. In-hospital mortality and morbidity were higher in the patients over 60 years of age (11% versus 2%, p=0.017 and 47% versus 31%, p=0.024). One-, 3-, and 5-year survival rates in the patients over 60 years of age were 81%, 58%, and 42%, respectively, compared to 90%, 59%, and 42% in the control patients (p=0.558). Unified model Cox regression analysis showed that resection margin status (hazard ratio 2.51) and ASA grade (hazard ratio 2.26), and not age, were determining factors for survival. This finding underlines the important fact that in patient selection for major liver resections, ASA grade is more important than patient age

Simulating human-robot teamwork dynamics for evaluation of work strategies in human-robot teams

To foster resilience in teams operating in complex work domains, design should allow for a range of work strategies as appropriate to context. This paper describes how computational simulation and network visualization of a team’s work can identify feasible work strategies and assess their appropriateness for different contexts. Network visualizations can identify constraints and dependencies that drive the feasible set of work strategies. After preliminary network analysis, these dependencies and inter-dependencies can be simulated in detail to better understand their impact. To illustrate, we describe a case study that explores two different work strategies that can each address the dependencies in a human-robot (rover) team in a manned space exploration mission

Cost of Liver Transplantation A Systematic Review and Meta-Analysis Comparing the United States With Other OECD Countries

Large cost variations of liver transplantation are reported. The aim of this study was to assess cost differences of liver transplantation and clinical follow-up between the United States and other Organization for Economic Cooperation and Development (OECD) countries. Eight electronic databases were searched, and 2,000 citations published after 1990 with more than 10 transplantations, and with original cost data, were identified. A total of 30 articles included 5,975 liver transplantations. Meta-analysis was used to derive a combined mean using a random-effects model to test for heterogeneity between studies. Estimated mean cost of a U. S. liver transplantation was US$163,438 (US$145,277-181,598) compared to US$103,548 (US$85,514-121,582) for other OECD countries. Patient characteristics, disease characteristics, quality of the health care provider, and methodology could not explain this cost difference. Health system characteristics differed between the U. S. and other OECD countries. Cost differences in liver transplantation between these two groups may be largely explained by health system characteristics

Does the meld system provide equal access to liver transplantation for patients with different ABO blood groups?

This study investigates the relationship between blood group and waiting time until transplantation or death on the waiting list. All patients listed for liver transplantation in the Netherlands between 15 December 2006 and 31 December 2012, were included. Study variables were gender, age, year of listing, diagnosis, previous transplantations, blood group, urgency, and MELD score. Using a competing risks analysis, separate cumulative incidence curves were constructed for death on the waiting list and transplantation and used to evaluate outcomes.In 517 listings, the mean death rate per 100 patient-years was 10.4. A total of 375 (72.5% of all listings) were transplanted. Of all transplantations, 352 (93.9%) were ABO-identical and 23 (6.1%) ABO-compatible. The 5-year cumulative incidence of death was 11.2% (SE 1.4%), and of transplantation 72.5% (SE 2.0%). Patient blood group had no multivariate significant impact on the hazard of dying on the waiting list nor on transplantation. Age, MELD score, and urgency status were significantly related to the death on the waiting list and transplantation. More recent listing had higher probability of being transplanted. In the MELD era, patient blood group status does not have a significant impact on liver transplant waiting list mortality nor on waiting time for transplantation

Outcome and pattern of recurrence after curative resection for hepatocellular carcinoma in patients with a normal liver compared to patients with a diseased liver

Background/Aims: The purpose of this study was to investigate whether differences existed in demography and outcome after resection for hepatocellular carcinoma (HCC) in patients with a normal liver compared to patients with a diseased liver. Methodology: Twenty-seven Caucasian patients with HCC in a histologically proven normal liver (NL group) in the Netherlands and 141 Asian patients with HCC in a diseased liver (DL group) in Japan underwent a curative liver resection. Patient and tumor characteristics, post-resectional disease-free, overall survival rates and pattern of recurrence were investigated. Results: HCC's in the NL group were found to be larger, in a more advanced stage and needed more extended resections compared to HCC's in the DL group. Microvascular invasion was similar in both groups, while capsule formation was observed less in the NL group. Overall survival and disease-free survival after curative resection were not statistically different between both groups. Also even after stratification for T-stage, there was no difference in survival Although the rate of recurrence was similar in both groups, a significantly higher number of extrahepatic metastases was observed in the NL group. Conclusions: Distinct demographic differences existed between patients with HCC in the NL group compared to patients in the DL group. Extrahepatic recurrences were more frequent after curative resection for HCC in a normal liver. No difference in survival was demonstrated between both groups

The Clinical Relevance of the Anhepatic Phase During Liver Transplantation

This study assesses the relation between the anhepatic phase duration and the outcome after liver transplantation. Of 645 patients who underwent transplantation between 1994 and 2006, 194 were recipients of consecutive adult primary piggyback liver transplants using heart-beating donors. The anhepatic phase was defined as the time from the physical removal of the liver from the recipient to recirculation of the graft. Other noted study variables were the cold and warm ischemia times, donor and recipient age, donor and recipient body mass index, perioperative red blood cell (RBC) transfusion, indication for transplantation, and Model for End-Stage Liver Disease score. The primary outcome parameter was graft dysfunction, which was defined as either primary nonfunction or initial poor function according to the Ploeg-Maring criteria. The median anhepatic phase was 71 minutes (37-321 minutes). Graft dysfunction occurred in 27 patients (14%). Logistic regression analysis showed an anhepatic phase over 100 minutes [odds ratio (OR), 4.28], a recipient body mass index over 25 kg/m(2) (OR, 3.21), and perioperative RBC transfusion (OR, 3.04) to be independently significant predictive factors for graft dysfunction. One-year patient survival in patients with graft dysfunction was 67% versus 92% in patients without graft dysfunction (P <0.001). A direct relation between the anhepatic phase duration and patient survival could, however, not be established. In conclusion, this study shows that liver transplant patients with an anhepatic phase over 100 minutes have a higher incidence of graft dysfunction. Patients with graft dysfunction have significantly worse 1-year patient survival. Liver Transpl 15:1050-1055, 2009. (C) 2009 AASLD

Surgical injuries of postmortem donor livers:Incidence and impact on outcome after adult liver transplantation

The exact frequency and clinical consequences of surgical hepatic injuries during organ procurement are unknown. We analyzed the incidence, risk factors, and clinical outcome of surgical injuries in 241 adult liver grafts. Hepatic injuries were categorized as parenchymal, vascular, or biliary. Outcome variables were bleeding complications, hepatic artery thrombosis (HAT), and graft survival. In 82 livers (34%), 96 injuries were detected. Most injuries were minor, but clinically relevant injuries were detected in 6.6% (16/241) of the livers. Fifty (21%) liver grafts had some degree of parenchymal or capsular injury, 40 (17%) had vascular injury, and 6 (2%) had an injury to the bile duct. Procurement region was the only risk factor significantly associated with surgical injury. The rate of hepatic artery injury was significantly higher in livers with aberrant arterial anatomy. Bleeding complications were found in 18% of patients who received livers with a parenchymal or capsular injury in contrast to 9% without parenchymal injury (P = 0.065). HAT was found in 23% of the patients who received a liver with arterial injury compared to 4% without arterial injury (P = 0.001). Overall graft survival rates were not significantly different for grafts with or without anatomical injury. In conclusion, surgical injuries of donor livers are an underestimated problem in liver transplantation and can be observed in about one-third of all cases. Clinically relevant injuries are detected in 6.6% of all liver grafts. Arterial injuries are associated with an increased risk of HAT