RESUMEN
BACKGROUND: Transcatheter aortic valve implants (TAVI) have revolutionised the treatment of elderly patients requiring aortic valve replacement. These patients often do not tolerate balloon valvuloplasty well, and a valvuloplasty balloon that would allow a degree of continued cardiac output during expansion would be beneficial. We tested such a balloon and describe our results in the sheep model. METHODS AND RESULTS: We developed a non-occlusive balloon (NOB) catheter. An acute experiment was performed where the NOB was inflated in six sheep in the aortic valve position without any attempt to arrest cardiac output. Two inflations were performed per animal: the first for 30 s and the second for 2-3 min. Standard occlusive balloons were inflated in two animals under rapid ventricular pacing to serve as controls. Mean pressure gradient across the NOB was 9.7 ± 5 mmHg during the inflations and all animals remained hemodynamically stable during NOB inflations. CONCLUSIONS: The novel non-occlusive balloon catheter, which permitted uninterrupted cardiac output for a prolonged period without the need for pacing-induced temporary cessation of cardiac output, is both feasible and well tolerated in the acute sheep model.
Asunto(s)
Válvula Aórtica , Valvuloplastia con Balón/instrumentación , Cateterismo Cardíaco/instrumentación , Catéteres Cardíacos , Animales , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/fisiopatología , Gasto Cardíaco , Diseño de Equipo , Ensayo de Materiales , Modelos Animales , Presión , Prueba de Estudio Conceptual , Oveja Doméstica , Factores de TiempoRESUMEN
OBJECTIVE: Restenosis and the risk of sub-acute thrombosis still compromise the advantages of coronary stenting. This report aims to present a clinical audit of the first 100 patients to receive the South African-developed 'low injury' S-Flex coronary stent at Groote Schuur Hospital. METHODS: From September 1999 to March 2001, 102 patients received one or more S-Flex stents. There were no special criteria for the use of the S-Flex and the stents were used routinely with stents from other manufacturers. Procedural and patient demographic information was obtained through a retrospective examination of patient records. All but two patients were followed up through clinical interview or telephone contact six months or more after the procedure. The primary endpoint was clinical restenosis, defined as angiographic restenosis (> 50% diameter narrowing), or recurrence of significant symptoms of ischaemic heart disease or target lesion revascularisation (TLR) after discharge from the hospital, unless shown angiographically that the S-Flex was not implicated. RESULTS: Device success was achieved in all cases. There were five cases of in-hospital major adverse cardiac events (MACE), including the deaths of two patients who had initially presented with cardiogenic shock. The six-month MACE rate was 7.9%, the six-month TLR rate was 3.0% and the total six-month mortality was 4.0%. The clinical restenosis rate after six months was 7.1% and the total event-free survival (i.e. survival without MACE or clinical restenosis) at six months was 86.1%. CONCLUSION: The S-Flex stent has a low clinical restenosis rate in a non-selective population undergoing stenting for coronary artery disease.