Effect of posttraumatic donor's disseminated intravascular coagulation in intrathoracic organ donation and transplantation

Pig-to-human kidney transplantation using brain-dead donors as recipients: One giant leap, or only one small step for transplantkind?

Pig kidney xenotransplantation is increasingly regarded as a realistic solution to the current shortage of human organ donors for patients with end-stage organ failure. Recently, the news of three pig-to-human transplantation cases has awakened public interest. Notably, the case by the Alabama team reported detailed and important findings for the xenotransplantation field. Using a genetically modified pig, two porcine kidneys were transplanted into a brain-dead recipient. They applied several approaches established in the preclinical NHP study, including gene-edited pig kidney graft and preoperative laboratory inspection such as crossmatching and infection screening. The pig-to-human kidney xenotransplantation had no unexpected events during surgery or evidence of hyperacute rejection. Unfortunately, the grafts did not work appropriately, and the study had to be terminated due to the decompensation of the recipient. While this study demonstrated the outstanding achievement in this research area, it also revealed remaining gaps to move xenotransplantation to the clinic. While brain-dead human recipients could reinforce the compatibility achievements of gene-edited pigs in NHP, their pro-inflammatory and pro-coagulant environment, in combination with short-duration of experiments will limit the assessment of kidney function, infection and rejection risk post-transplant, in particular antibody-mediated rejection. The use of successful immunosuppressive protocols of non-human primates xenotransplant experiments including anti-CD154 antibody will be critical to maximize the success in the first in-human trials.

Management of the brain-dead donor in the ICU: general and specific therapy to improve transplantable organ quality

PURPOSE

To provide a practical overview of the management of the potential organ donor in the intensive care unit.

METHODS

Seven areas of donor management were considered for this review: hemodynamic management; fluids and electrolytes; respiratory management; endocrine management; temperature management; anaemia and coagulation; infection management. For each subchapter, a narrative review was conducted.

RESULTS AND CONCLUSIONS

Most elements in the current recommendations and guidelines are based on pathophysiological reasoning, epidemiological observations, or extrapolations from general ICU management strategies, and not on evidence from randomized controlled trials. The cardiorespiratory management of brain-dead donors is very similar to the management of critically ill patients, and the same applies to the management of anaemia and coagulation. Central diabetes insipidus is of particular concern, and should be diagnosed based on clinical criteria. Depending on the degree of vasopressor dependency, it can be treated with intermittent desmopressin or continuous vasopressin, intravenously. Temperature management of the donor is an area of uncertainty, but it appears reasonable to strive for a core temperature of > 35 °C. The indications and controversies regarding endocrine therapies, in particular thyroid hormone replacement therapy, and corticosteroid therapy, are discussed. The potential donor should be assessed clinically for infections, and screening tests for specific infections are an essential part of donor management. Although the rate of infection transmission from donor to receptor is low, certain infections are still a formal contraindication to organ donation. However, new antiviral drugs and strategies now allow organ donation from certain infected donors to be done safely.

Inflammatory signalling associated with brain dead organ donation: from brain injury to brain stem death and posttransplant ischaemia reperfusion injury

Brain death is associated with dramatic and serious pathophysiologic changes that adversely affect both the quantity and quality of organs available for transplant. To fully optimise the donor pool necessitates a more complete understanding of the underlying pathophysiology of organ dysfunction associated with transplantation. These injurious processes are initially triggered by catastrophic brain injury and are further enhanced during both brain death and graft transplantation. The activated inflammatory systems then contribute to graft dysfunction in the recipient. Inflammatory mediators drive this process in concert with the innate and adaptive immune systems. Activation of deleterious immunological pathways in organ grafts occurs, priming them for further inflammation after engraftment. Finally, posttransplantation ischaemia reperfusion injury leads to further generation of inflammatory mediators and consequent activation of the recipient's immune system. Ongoing research has identified key mediators that contribute to the inflammatory milieu inherent in brain dead organ donation. This has seen the development of novel therapies that directly target the inflammatory cascade.

Implications of donor disseminated intravascular coagulation on kidney allograft recipients

BACKGROUND AND OBJECTIVES

Disseminated intravascular coagulation (DIC) is common in deceased kidney donors and is considered a relative contraindication to donation. The significance of donor DIC on recipient kidney function is poorly understood. Additionally, the significance of thrombocytopenia in recipients of kidneys from DIC-positive donors is understudied.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a retrospective cohort of 162 kidney transplants, the presence of DIC in donors, the occurrence of thrombocytopenia in recipients, and risk factors for delayed or slow graft function (DGF/SGF) were assessed. The effects of DIC donor status on DGF/SGF in the study sample as a whole, and of thrombocytopenia on DGF/SGF in recipients of DIC-positive kidneys specifically, were examined using multiple logistic regression.

RESULTS

DIC donor status was not associated with occurrence of DGF/SGF, but thrombocytopenia was significantly associated with DIC-positive donor status (P=0.008). Thrombocytopenia was independently associated with DGF/SGF only in the recipients of DIC-positive kidneys (P=0.005). Patient and graft survival at 1 year were not affected by donor DIC status or by thrombocytopenia status.

CONCLUSIONS

Donor DIC was not associated with short-term suboptimal graft function, defined as DGF/SGF, nor with long-term patient or graft survival. However, thrombocytopenia appears to portend DGF/SGF in recipients of DIC-positive kidneys and may be a clinical sign on which the basis of therapeutic decisions could be undertaken.

Donor age is associated with chronic allograft vasculopathy after adult heart transplantation: implications for donor allocation

BACKGROUND

Chronic allograft vasculopathy (CAV) is a major cause of long-term complications and mortality after heart transplantation. Although recipient factors have been implicated, little is known of the role of donor factors in CAV development. We sought to identify donor factors associated with development of CAV after heart transplantation.

METHODS

We reviewed the United Network for Organ Sharing heart transplant database from August 1987 to May 2008. Univariate and multivariate analyses were performed to assess the association between donor variables and the onset of CAV for adult recipients. Donor age was matched to recipient age and analyzed with respect to development of CAV.

RESULTS

Of the 39,704 recipients, a total of 11,714 (29.5%) experienced CAV. Multivariate analysis demonstrated seven donor factors as independent predictors of CAV: age, ethnicity, sex, weight, history of diabetes, hypertension, and tobacco use. When matching young donors (0 to 19.9 years) and old donors (> or =50 years) to each recipient age group, older donors (> or =50 years) conferred a higher risk of developing CAV. Further modeling demonstrated that for each recipient group, older donor age (> or =50 years) conferred a higher risk of CAV development compared with younger donor age (0 to 19.9 years; p < 0.0001).

CONCLUSIONS

Donor factors including sex, hypertension, diabetes, and tobacco use are independently associated with recipient CAV. Older donor age confers a greater risk of CAV development regardless of the age of the recipient. A heightened awareness for the development of CAV is warranted when using older donors in adult cardiac transplantation, in particular with recipients 40 years of age or older.

Overview of lung transplantation

Although significant gains have been made in improving lung function and survival in cystic fibrosis (CF), ultimately respiratory failure is the leading cause of mortality in these patients. For CF patients with end stage lung disease, lung transplantation is an option for treatment. The field of lung transplantation has progressed markedly in the last 20 years. Nonetheless it remains a technically complex and challenging procedure, and patients are at risk for numerous short term and long term complications. Potential transplant recipients must be physically and psychologically prepared for the arduous process involved in lung transplantation. This article will review the history of lung transplantation, indications for transplantation, surgical techniques, and complications of transplantation.