The Gore Global Registry for Endovascular Aortic Treatment: Objectives and Design.

BACKGROUND: The Global Registry for Endovascular Aortic Treatment (GREAT) is a prospective observational multicenter cohort registry that was initiated in November 2011. The aim of the GREAT is to collect contemporary real-world data on the performance of all Gore aortic endografts in the treatment of multiple aortic pathologies. The primary and secondary objectives, design, and future directions of the GREAT are described. METHODS: The GREAT aims to enroll 5000 consecutive patients with Gore thoracic and abdominal aortic endografts from multiple centers throughout the world. The GREAT has broad inclusion criteria with minimal exclusion criteria to reflect real-world practice such as including off-label use, nonstandard indications and devices deployed outside instruction for use. Follow-up will extend to 10 years providing major insights into the long-term durability and behavior of Gore aortic endografts. Primary end points include the incidence and timing of (1) endoleak of any type, (2) endograft migration and/or stent fracture, (3) endograft explantation, and (4) aortic rupture. Secondary end points include the following: (1) incidence of serious device events by pathology, (2) incidence of serious device events by aortic segment (ascending aorta, arch of aorta, descending thoracic aorta, abdominal aorta), (3) long-term survival by pathology, and (4) aorta-related mortality by pathology. RESULTS: As of June 2015, 2960 patients have been enrolled into the GREAT from 78 centers in Europe, the United States, Australia, New Zealand, and Brazil. The majority of patients and centers are from Europe and the United States. Completion of enrollment is anticipated to be in 2017 with interim results planned to be published during enrollment and on follow-up. CONCLUSIONS: Upon completion, the GREAT will be among the largest clinical registry to date of abdominal and thoracic aortic devices manufactured by a single sponsor. It will provide valuable real-world data on the use and durability of Gore aortic endografts in the treatment of a variety of aortic pathologies and devices deployed within and outside instruction for use.

In vivo human electrochemical properties of a NiTi-based alloy (Nitinol) used for minimally invasive implants.

The development of a homemade device for in vivo human determination of the open circuit potential (OCP) of Nitinol is described. Pseudo-reference electrodes (316L stainless steel and Pt) were initially tested and validated in vitro using simulated body fluids. As judged from the excellent electrochemical responses in terms of both accuracy and precision, the most ideal system comprised the combination of sterilized Pt (pseudo-reference) and Nitinol (working) needle-shaped electrodes. The average in vivo human OCP determined from independent measurements on six human patients with indication of direct arterial surgery was -0.334 +/- 0.030 V/SCE. This value was in good agreement with data recorded in vitro using simulated body fluids (-0.313 +/- 0.003 V/SCE in AFNOR S90-701 artificial saliva; -0.334 +/- 0.001 V/SCE in artificial urine; -0.239 +/- 0.007 V/SCE in Ringer's solution). The thin surface film protecting the bulk NiTi alloy is therefore not susceptible to active dissolution at rest as long as the break down potentials (>>0.0 V/SCE) so far reported are well above OCP measured in this study. These results highlight the importance of evaluating the corrosion resistance of Nitinol under realistic conditions (mechanical loads, wear and fatigue) in order to establish multifaceted mechanisms that might lead to accelerated dissolution and failure of implanted stents.

"Stent" auto-expansível nas dissecções da aorta tipo B / Self-expanding stent in type B dissections of the aorta

O tratamento clínico das dissecções agudas da aorta do tipo B tem mortalidade em torno de 25 por cento menor que a mortalidade cirúrgica. O tratamento cirúrgico das dissecções crônicas também produz uma morbidade e mortalidade elevadas. A utilização de "stents"auto-expansíveis endovasculares pode ser uma nova alternativa no tratamento destas lesões. De abril a dezembro de 1998 foram implantados 15 "stents" endovasculares, 10 em dissecções agudas e 5 em crônicas. A idade dos pacientes variou entre 48 e 75 anos (média=60,53/9,73 anos) com 66,6 por cento do sexo masculino. Os pacientes foram submetidos à esternotomia mediana, circulação extracorpórea (CEC) com hipotermia profunda (18/ - 20/C), parada circulatória total (PCT) e perfusão cerebral retrógrada (PCR). A aorta transversa foi incisada e implantado o "stent" na aorta descendente sob auxílio de aortoscopia. Foram analisados os tempos de CEC, pinçamento aórtico, PCT, PCR, reaquecimento, ventilação mecânica, internação, sangramento trans e pós-operatório, reposição sangüínea, gasometria, curva de eventos e sobrevida. A mortalidade hospitalar (30 dias) foi de 6,6 por cento; 2 pacientes foram reoperados com 3 e 6 meses após a operação com dissecção da aorta ascendente e aneurisma roto distal ao "stent". Quatorze vêm sendo acompanhados com 1 a 8m de evolução, sendo que 85,7 por cento estão livres de eventos e curva de sobrevida de 93,1 por cento (240 dias). Concluímos que o implante de "stent"intraluminais auto-expansíveis apresentou mortalidade menor na fase aguda da doença (6,6 por cento) comparada à nossa experiência anterior com o tratamento clínico (30 por cento). Apesar da amostra ser pequena, o procedimento parece ser promissor e necessita mais acompanhamento