Organ procurement and transplantation network. Final rule.

: HHS is issuing this final rule (herein referred to as ``this rule'') to add vascularized composite allografts (VCAs) as specified herein to the definition of organs covered by the rules governing the operation of the Organ Procurement and Transplantation Network (OPTN) (herein referred to as the OPTN final rule). When it enacted the National Organ Transplant Act in 1984, Congress included a definition of the term organ and authorized the Secretary to expand this definition by regulation. The Secretary has previously exercised this authority and expanded the statutory definition of organ. Prior to this rule, the OPTN final rule defined covered organs as ``a human kidney, liver, heart, lung, or pancreas, or intestine (including the esophagus, stomach, small and/or large intestine, or any portion of the gastrointestinal tract). Blood vessels recovered from an organ donor during the recovery of such organ(s) are considered part of an organ with which they are procured for purposes of this part if the vessels are intended for use in organ transplantation and labeled `For use in organ transplantation only.' '' This rule also includes a corresponding change to the definition of human organs covered by section 301 of the National Organ Transplant Act of 1984, as amended (NOTA).

Composite tissue allotransplantation: a proposed classification system based on relative complexity.

Numerous achievements have been made encompassing a wide array of composite tissue allograft (CTA) subtypes. We sought to develop a simple, reproducible CTA classification system for the purpose of comparing clinical investigation. Each CTA subtype differs in relative complexity and can therefore be theoretically classified based on its unique combination of multiple factors. Eight complexity factors (CFs) are hypothesized: anatomic detail, psychological obstacles, rejection risk, required rehabilitation, relative antigenicity, functionality/cosmesis, skin ratio, and salvageability. A distribution of total complexity scores, ranging from 8 to 24, is classified into 3 ordered categories representing varying degrees of complexity. In conclusion, we have created a new classification system so that ongoing research and future data may be compared in a type-specific fashion.

Composite tissue allotransplantation: classification of clinical acute skin rejection.

BACKGROUND: Composite tissue allotransplantation (CTA) is a recently introduced option for limb replacement and reconstruction of other nonreconstructible tissue defects. As with recipients of other allotransplants, CTA recipients can experience rejection episodes that are presumed to be mediated by immune mechanisms similar to those affecting solid organ grafts. However, a systematic examination of this process has not been performed, and there are no standardized criteria for the description of severity or type of rejection METHODS: We collected biopsies from human limb allografts and abdominal walls in various stages of rejection for histological and immunohistochemical analysis to formulate a CTA rejection scheme. Biopsies were ranked by severity and reproducibility of the system was tested using a second set of biopsies. Tissue slides were examined blindly by three pathologists and the nonparametric Kendall coefficient of concordance (W) was used to assess the amount of agreement among the pathologists in their classification grades. RESULTS: Rejection initially appeared as a perivascular infiltrate progressing to involve the dermis. Arteritis was observed only in the medium to large size arteries of the subcutis. Myositis was seen occasionally. Perineural involvement without frank neuritis was present in advanced rejection. The infiltrate was predominantly CD4+ in milder cases and CD8+ in advanced cases. HLA-DR was minimally expressed in keratinocytes even in severe rejection. Kendall's W was 0.9375 (p

Superior durability of SynerGraft pulmonary allografts compared with standard cryopreserved allografts.

BACKGROUND: The ideal pulmonary valve replacement for children and adolescents remains elusive. Although favored by many surgeons, the cryopreserved pulmonary allograft tends to become rapidly incompetent and elicits an immune response. The SynerGraft process (Cryolife Inc, Kennesaw, GA) decellularizes a pulmonary allograft, leaving a scaffold of connective tissue. These grafts have been shown to decrease immune reactivity and become populated with host cells. Although theoretically these traits may improve durability, few data comparing SynerGraft-processed allografts (SynAs) (Cryolife Inc) with standard cryopreserved allografts are available. METHODS: A single institution review was performed for all SynAs implanted from their introduction in 2001 to January 2003. Twenty-six patients with SynAs and 26 age and diagnosis-matched controls receiving cryopreserved allografts were evaluated. Subjects were analyzed for demographics, survival, reintervention, and echocardiographic findings. RESULTS: There were no significant differences between groups in age, weight, valve diameter, orthotopic and heterotopic allograft position, or follow-up. On echocardiogram there was no difference in initial degree of allograft insufficiency or gradient. However, at mean follow-up of 19 +/- 13 months, SynAs were significantly less regurgitant than cryopreserved allografts (p = 0.017). Although all gradients were low, a significant difference between SynAs (7.6 +/- 14 mm Hg) and cryopreserved allografts (14.6 +/- 15.6 mm Hg; p = 0.012) had emerged. Survival was identical at 85% (22 of 26). Rates of reintervention were similar at 7% (2 of 26) for cryopreserved allografts and 3.8% (1 of 26) for SynAs (p = 0.98). CONCLUSIONS: At intermediate follow-up, the SynA demonstrated greater durability with less insufficiency and lower gradients. These characteristics are important to many patients with complex congenital heart disease; however, long-term effects on survival and reintervention remain unknown.

Reflexiones sobre la infeccíon protésica / Reflections on protesic infection

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Trasplante de células de cordón umbilical

El trasplante de médula ósea ha demostrado su eficacia en diferentes patologías inmunológicas y hematopoyéticas. Se ha demostrado que las células de cordón umbilical como fuente de células progenitoras para trasplante alogénico en niños son de gran eficacia con menores complicaciones de tipo reacción de injertocontra huésped y mayores posibilidades para encontrar donantes HLA compatibles. La mayoría de los trasplantes que se han llevado a cabo con células de cordón umbilical han sido con donantes HLA idénticos intrafamiliares, sin embargo, el interés en este procedimiento es su gran potencial como fuente para donantes no relacionados. El uso de células de cordón umbilical implica el desarrollo de bancos de almacenamiento. Esta es una revisión de la experiencia clínica internacional, la composición de las células de cordón, los métodos de recolección y control de calidad.