RESUMEN
For donation after circulatory death (DCD), many centers allow 1 h after treatment withdrawal to donor death for kidneys. Our center has consistently allowed 2 h. We hypothesized that waiting longer would be associated with worse outcome. A single-center, retrospective analysis of DCD kidneys transplanted between 2008 and 2013 as well as a nationwide survey of organ procurement organization DCD practices were conducted. We identified 296 DCD kidneys, of which 247 (83.4%) were transplanted and 49 (16.6%) were discarded. Of the 247 recipients, 225 (group 1; 91.1%) received kidneys with a time to death (TTD) of 0-1 h; 22 (group 2; 8.9%) received grafts with a TTD of 1-2 h. Five-year patient survival was 88.8% for group 1, and 83.9% for group 2 (p = 0.667); Graft survival was also similar, with 5-year survival of 74.1% for group 1, and 83.9% for group 2 (p = 0.507). The delayed graft function rate was the same in both groups (50.2% vs. 50.0%, p = 0.984). TTD was not predictive of graft failure. Nationally, the average maximum wait-time for DCD kidneys was 77.2 min. By waiting 2 h for DCD kidneys, we performed 9.8% more transplants without worse outcomes. Nationally, this practice would allow for hundreds of additional kidney transplants, annually.
Asunto(s)
Muerte Encefálica , Rechazo de Injerto/prevención & control , Paro Cardíaco , Fallo Renal Crónico/cirugía , Donantes de Tejidos/estadística & datos numéricos , Obtención de Tejidos y Órganos/métodos , Adulto , Selección de Donante , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Supervivencia de Injerto , Hospitales de Alto Volumen , Humanos , Pruebas de Función Renal , Trasplante de Riñón , Masculino , Persona de Mediana Edad , Pronóstico , Sistema de Registros , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Obtención de Tejidos y Órganos/estadística & datos numéricos , Estados UnidosRESUMEN
In transplantation, immunosuppression has been directed at controlling acute responses, but treatment of chronic rejection has been ineffective. It is possible that factors that have previously been unaccounted for, such as exposure to inhaled pollution, ultraviolet light, or loss of the normal equilibrium between the gut immune system and the outside environment may be responsible for shifting immune responses to an effector/inflammatory phenotype, which leads to loss of self-tolerance and graft acceptance, and a shift towards autoimmunity and chronic rejection. Cells of the immune system are in a constant balance of effector response, regulation, and quiescence. Endogenous and exogenous signals can shift this balance through the aryl hydrocarbon receptor, which serves as a thermostat to modulate the response one way or the other, both at mucosal surfaces of interface organs to the outside environment, and in the internal milieu. Better understanding of this balance will identify a target for maintenance of self-tolerance and continued graft acceptance in patients who have achieved a "steady state" after transplantation.
Asunto(s)
Exposición a Riesgos Ambientales/efectos adversos , Rechazo de Injerto/etiología , Tolerancia Inmunológica/inmunología , Trasplante de Órganos/efectos adversos , Animales , HumanosRESUMEN
BACKGROUND AND PURPOSE: Approaches to management of intracranial aneurysms are inconsistent, in part due to apprehension relating to potential malpractice claims. The purpose of this article was to review the causes of action underlying medical malpractice lawsuits related to the diagnosis and management of intracranial aneurysms and to identify the factors associated and their outcomes. MATERIALS AND METHODS: We consulted 2 large legal databases in the United States to search for cases in which there were jury awards and settlements related to the diagnosis and management of patients with intracranial aneurysms in the United States. Files were screened to include only those cases in which the cause of action involved negligence in the diagnosis and management of a patient with an intracranial aneurysm. RESULTS: Between 2000 and 2020, two hundred eighty-seven published case summaries were identified, of which 133 were eligible for inclusion in the analysis. Radiologists constituted 16% of 159 physicians sued in these lawsuits. Failure to diagnose was the most common medical malpractice claim referenced (100/133 cases), with the most common subgroups being "failure to include cerebral aneurysm as a differential and thus perform adequate work-up" (30 cases), and "failure to correctly interpret aneurysm evidence on CT or MR imaging" (16 cases). Only 6 of these 16 cases were adjudicated at trial, with 2 decided in favor of the plaintiff (awarded $4,000,000 and $43,000,000, respectively). CONCLUSIONS: Incorrect interpretation of imaging is relatively infrequent as a cause of malpractice litigation compared with failure to diagnose aneurysms in the clinical setting by neurosurgeons, emergency physicians, and primary care providers.
Asunto(s)
Aneurisma Intracraneal , Mala Praxis , Humanos , Estados Unidos , Aneurisma Intracraneal/diagnóstico por imagen , Aneurisma Intracraneal/terapia , Radiólogos , Neurocirujanos , Bases de Datos FactualesRESUMEN
Over a 23-year period, our center performed 82 renal retransplants in prior simultaneous pancreas-kidney recipients with functioning pancreatic allografts. All patients were insulin-independent at retransplantation. We aimed to quantify the risk of returning to insulin therapy and to identify factors that predispose patients to pancreatic allograft failure after renal retransplantation. Among these 82 patients, pancreatic allograft survival after renal retransplantation was 78%, 49% and 40% at 1, 5 and 10 years. When analyzing risk factors, we unexpectedly found no clear relationship between the cause of primary renal allograft failure, hemoglobin A1c (HbA1c) or fasting C-peptide level at retransplant and subsequent pancreatic allograft failure. An elevated HbA1c in the month after renal retransplant correlated with subsequent pancreatic graft loss and patients experiencing pancreatic graft loss were more likely to subsequently lose their renal retransplant. Although it is difficult to prospectively identify those patients who will return to insulin therapy after repeat renal transplantation, the relatively high frequency of this event mandates that this risk be conveyed to patients. Nonetheless, the survival benefit associated with renal retransplantation justifies pursuing retransplantation in this population.
Asunto(s)
Nefropatías Diabéticas/cirugía , Rechazo de Injerto/etiología , Supervivencia de Injerto , Trasplante de Riñón/patología , Trasplante de Páncreas/patología , Complicaciones Posoperatorias , Adulto , Péptido C/metabolismo , Femenino , Estudios de Seguimiento , Hemoglobina Glucada/metabolismo , Rechazo de Injerto/mortalidad , Humanos , Trasplante de Riñón/inmunología , Trasplante de Riñón/mortalidad , Masculino , Trasplante de Páncreas/inmunología , Trasplante de Páncreas/mortalidad , Reoperación , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Trasplante HomólogoRESUMEN
The role of humoral alloreactivity in ABO-compatible liver transplantation remains unclear. To understand the significance of donor-specific HLA alloantibodies (DSA) in liver rejection, we applied the currently used strategy for detection of antibody-mediated rejection of other solid allografts. For this purpose we reviewed the data on 43 recipients of ABO identical/compatible donor livers who had indication liver biopsy stained for complement element C4d and contemporaneous circulating DSA determination. Seventeen (40%) patients had significant circulating DSA in association with diffuse portal C4d deposition (DSA+/diffuse C4d+). These DSA+/diffuse C4d+ subjects had higher frequency of acute cellular rejection (ACR) 15/17 versus 13/26 (88% vs. 50%), p = 0.02, and steroid resistant rejection 7/17 versus 5/26 (41% vs. 19%), p = 0.03. Based on detection of the combination DSA+/diffuse C4d+, 53.6% of cases of ACR had evidence of concurrent humoral alloreactivity. Six of the 10 patients with ductopenic rejection had circulating DSA and diffuse portal C4d, three of whom (2 early and 1 late posttransplantation) developed unrelenting cholestasis, necessitating specific antibody-depleting therapy to salvage the allografts. Thus, in ABO-compatible liver transplantation humoral alloreactivity mediated by antibodies against donor HLA molecules appears to be frequently intertwined with cellular mechanisms of rejection, and to play a role in ductopenia development.
Asunto(s)
Sistema del Grupo Sanguíneo ABO/inmunología , Enfermedades de los Conductos Biliares/etiología , Rechazo de Injerto/inmunología , Antígenos de Histocompatibilidad Clase I/inmunología , Isoanticuerpos/sangre , Trasplante de Hígado/inmunología , Donantes de Tejidos , Adolescente , Adulto , Anciano , Enfermedades de los Conductos Biliares/patología , Complemento C4b/inmunología , Complemento C4b/metabolismo , Femenino , Citometría de Flujo , Humanos , Trasplante de Hígado/mortalidad , Masculino , Persona de Mediana Edad , Fragmentos de Péptidos/inmunología , Fragmentos de Péptidos/metabolismo , Factores de Riesgo , Trasplante Homólogo/inmunología , Resultado del Tratamiento , Adulto JovenRESUMEN
We studied the effects of indirect allorecognition on the induction and maintenance phases of tolerance in miniature swine cotransplanted with heart and kidney allografts. MHC class I-mismatched heart and kidney grafts were cotransplanted in recipients receiving CyA for 12 days. Recipients were unimmunized or immunized with a set of donor-derived or control third-party MHC class I peptides either 21 days prior to transplantation or over 100 days after transplantation. T-cell proliferation, delayed type hypersensitivity reaction (DTH) and antibody production were assessed. All animals injected with donor MHC class I peptides developed potent indirect alloresponses specific to the immunizing peptides. While untreated recipients developed stable tolerance, all animals preimmunized with donor allopeptides rejected kidney-heart transplants acutely. In contrast, when peptide immunization was delayed until over 100 days after kidney-heart transplantation, no effects were observed on graft function or in vitro measures of alloimmunity. Donor peptide immunization prevented tolerance when administered to recipients pre transplantation but did not abrogate tolerance when administered to long-term survivors post transplantation. This suggests that the presence of T cells activated via indirect allorecognition represent a barrier to the induction but not the maintenance of tolerance.
Asunto(s)
Trasplante de Corazón/inmunología , Antígenos de Histocompatibilidad Clase I/inmunología , Tolerancia Inmunológica , Trasplante de Riñón/inmunología , Animales , Ensayo de Inmunoadsorción Enzimática , Hipersensibilidad Tardía , Porcinos , Porcinos Enanos , Trasplante HomólogoRESUMEN
We compared plain chest radiographs, standard (bones white) digitized images, and inverse-intensity (bones black) images to determine their ability to identify pathologically confirmed malignant pulmonary nodules. The images were digitized by using a photo-optical laser scanner and were displayed on a 1024 x 1024 x 8 bit system capable of operator-controlled magnification (2x or 4x) and nonlinear (logarithmic/exponential) contrast transformation in both standard and inverse-intensity modes. Receiver-operator curve analysis was used to study the detection performance of six observers who viewed 40 images obtained in 15 normal subjects and 25 abnormal subjects. There was no statistically significant difference in the area under the ROC curve between the standard digital images and the plain chest radiographs. However, ROC areas were significantly greater (p less than or equal to .05) for inverse-intensity digital images when compared with either standard-intensity digital images or plain chest radiographs. These results suggest that inverse-intensity images may have some advantages in the detection of pulmonary nodules.
Asunto(s)
Neoplasias Pulmonares/diagnóstico por imagen , Curva ROC , Intensificación de Imagen Radiográfica/métodos , Nódulo Pulmonar Solitario/diagnóstico por imagen , HumanosRESUMEN
A classification test was used to compare the results of digitizing chest radiographs with a linear diode array camera and a laser scanner. The ability of B readers to classify a pneumoconiosis test set from original radiographs and the digitized images was compared. The classification of profusion was impaired when images were digitized with the diode array camera but not when they were digitized with the laser scanner. The impairment found with images digitized with the linear diode array camera was overcome with use of a zoom function at the display station. The size of areas of opacification was overestimated on images from both scanners. Variation between and within observers (kappa approximately equal to 0.6) was consistent over observers and over modalities.