Comparison of Small Blood Vessel Diameter with Intravascular Ultrasound and Coronary Angiography for Guidance of Percutaneous Coronary Intervention.

Major cardiovascular events (MACEs) are a cause of major mortality worldwide. The narrowing and blockage of coronary arteries with atherosclerotic plaques are diagnosed and treated with percutaneous coronary intervention (PCI). During this procedure, coronary angiography (CAG) remains the most widely used guidance modality for the evaluation of the affected blood vessel. The measurement of the blood vessel diameter is an important factor to consider in order to decide if stent colocation is suitable for the intervention. In this regard, a small blood vessel (<2.75 mm) is majorly left without stent colocation; however, small vessel coronary artery disease (SvCAD) is a significant risk factor for the recurrence of MACEs, maybe due to the lack of a standardized treatment related to the diameter of the affected blood vessel; therefore, a more precise measurement is needed. The use of CAG for the measurement of the blood vessel diameter has some important limitations that can be improved with the use of newer techniques such as intravascular ultrasound (IVUS), although at higher costs, which might explain its underuse. To address differences in blood vessel diameter measurements and identify specific cases where IVUS might be of additional benefit for the patient, we conducted a retrospective study in patients who underwent PCI for MACEs with affection for at least one small blood vessel. We compared the measurements of the affected small blood vessels' diameter obtained by CAG and IVUS to identify cases of reclassification of the affected blood vessel; additionally, we underwent a multivariate analysis to identify risk factors associated with blood vessel reclassification. We included information from 48 patients with a mean ± SD age of 69.1 ± 11.9 years; 70.8% were men and 29.2% were women. The mean diameter with CAG and IVUS was 2.1 mm (95% CI 1.9-2.2), and 2.8 (2.8-3.0), respectively. The estimated difference was of 0.8 mm (95% CI 0.7-0.9). We found a significant positive low correlation in diameter measurements of small blood vessels obtained with CAG and IVUS (r = 0.1242 p = 0.014). In total, 37 (77%) patients had a reclassification of the affected blood vessel with IVUS. In 21 cases, the affected blood vessel changed from a small to a medium size (2.75-3.00 mm), and in 15 cases, the affected vessel changed from a small to a large size (<3.00 mm). The Bland-Altman plot was used to evaluate agreement in measurements with CAG and IVUS. The change in blood vessel classification with IVUs was important for the decision of intervention and stent collocation. The only variable associated with reclassification of blood vessels after adjustment in a multivariate analysis was T2D (type 2 diabetes) (p = 0 0.035). Our findings corroborate that blood vessels might appear smaller with CAG, especially in patients with T2D; therefore, at least in these cases, the use of IVUS is recommended over CAG.

Guidelines for the Execution of True Spherical Osteotomies Using a Modified Dome Blade Design.

OBJECTIVES: The purpose of this study was to explore the trigonometric principles of the spherical osteotomy, establish guidelines for its application and test the guidelines on bone models using a new blade design. We propose a new rule of osteotomies incorporating the outlined geometric principles, and applicable to the use of spherical cuts in veterinary orthopaedic surgery. MATERIALS AND METHODS: The trigonometric principles for the execution of neutral, closing and opening spherical osteotomies were explored in silico. A modification of the existing commercially available dome blade was designed and manufactured such that it facilitated the performance of spherical osteotomy with a minimized blade radius. A pilot study was performed whereby the modified dome blade was used to create spherical osteotomy in canine radial bone models. The surfaces of the osteotomy models were laser-scanned using a three-dimensional (3D) scanner; the resultant scans were imported into and analysed using a commercial 3D analysis software. The accuracy of osteotomy execution was measured as the distance between the targeted centre of osteotomy and the actual centre of osteotomy as found on the 3D scans. RESULTS: By utilizing the geometric principles of spherical osteotomy, an accurate osteotomy position was achieved. The centre of the spherical cut performed on bone models was confirmed to be within 5% tolerance of the location as planned in silico demonstrating the accurate and relevant clinical application of geometric principles. CLINICAL SIGNIFICANCE: The trigonometric guidelines for the execution of spherical osteotomy can be applied in a pre-clinical environment with accuracy. The new guidelines combined with the proposed new rule for spherical osteotomy utilizing the new blade design are translatable into clinical application, permitting the surgeon to accurately plan osteotomy application while mitigating the significant loss of bone-to-bone contact during correction of torsional deformities inherent in the principles of dome osteotomy use.

Prevalence of patent foramen ovale determined by transesophageal echocardiography in patients with cryptogenic stroke aged 55 years or older. Same as younger patients?

INTRODUCTION AND OBJECTIVES: To investigate the relationship between patent foramen ovale and cryptogenic stroke in patients aged > or =55 years. METHODS: This prospective study determined the presence of patent foramen ovale and atrial septal aneurysm using transesophageal echocardiography in 262 consecutive patients with a diagnosis of probable cryptogenic stroke. Data from 44 patients aged > or =55 years with cryptogenic stroke (Group A) were compared with those from two other groups: 194 patients aged <55 years with cryptogenic stroke (Group B) and 24 control patients aged > or =55 years with stroke of known origin, namely grade III-V aortic atheromatosis (Group C). RESULTS: The frequency of patent foramen ovale in Group A was similar to that in Group B (38% vs. 36%; P=.85) but significantly higher than that in Group C (38% vs. 8%; P=.029). The frequency of patent foramen ovale with concomitant atrial septal aneurysm was significantly higher in the study group (Group A) than in the control Group C (18% vs. 0; P=.039) and non-significantly higher than in Group B (18% vs. 11%; P=.11). CONCLUSIONS: The frequency of patent foramen ovale alone or in association with atrial septal aneurysm in patients with cryptogenic stroke aged > or =55 years was similar to that in those aged <55 years, but higher than that in patients aged > or =55 years with stroke of atherosclerotic origin. These data suggest that paradoxical embolism could be a cause of stroke in both age groups.

Oral phenylalanine loading test for the diagnosis of dominant guanosine triphosphate cyclohydrolase 1 deficiency.

OBJECTIVES: To evaluate the usefulness of Phe loading test in patients for the diagnosis of guanosine triphosphate cyclohydrolase 1 deficiency (GTPCH). DESIGN AND METHODS: We studied one family composed of 13 members harbouring the Q89X mutation in the GTPCH gene, a non-related pediatric patient with GTPCH deficiency and 8 pediatric controls. 100 mg/kg of L-phenylalanine was orally administered, and blood spot samples were taken at baselines 1, 2, 4 and 6 h post-load. RESULTS: Two out of 7 pediatric patients showed a phenylalanine/tyrosine ratio higher than the previously reported cut-off value of 5.25 at 4 h, while 6 of the 7 adult patients showed a higher value. The only adult patient with a phenylalanine/tyrosine ratio below 5.25 at 4 h was asymptomatic. CONCLUSIONS: A cut-off value of 5.25 seems reliable for interpreting Phe loading test in adult patients with GTPCH deficiency, although a lower value should be established for pediatric patients.

Diseño y desarrollo de un nuevo anillo de soporte para bioprotesis valvular cardiaca, porcina y/o humana -BioSTENT- / Designe and develop of new support ring for bioprothetic cardiac valves -BioSTENT-

Introducción: la experiencia clínica ha demostrado que el anillo de soporte de la bioprótesis valvular cardíaca (ASBVC) ejerce un importante papel en la operatividad del implante. Los resultados tras la utilización de múltiples modelos, han ampliado el estado del arte en el diseño y desarrollo de dichos anillos; aún así, no se logra un anillo que opere como el soporte natural. Dada la importancia del ASBVC, la fabricación en el ámbito nacional de bioprótesis valvular cardíaca (BVC) se ve limitada porque los fabricantes multinacionales sólo ponen a disposición el conjunto valvular bioprotésico, por lo que no se cuenta con el ASBVC aislado; además, pesa sobre éstos una patente que impide su réplica y prohibe su producción industrial. Objetivos: desarrollar un nuevo modelo de ASBVC, con mejores prestaciones, considerando los aspectos funcionales más relevantes para un soporte de alto comportamiento. Evaluar los diseños mediante técnicas computadorizadas y máquinas de pruebas especialmente construidas. Materiales y métodos: mediante técnicas de estática y dinámica, considerando variables de flexibilidad, distribución de cargas y tensión, y condiciones de operación, se hace un diseño conceptual de ASBVC. Luego se realiza un diseño geométrico dimensional teniendo en cuenta los aspectos anatómicos y el montaje del tejido biológico. Se selecciona un material que cumpla con los requerimientos de compatibilidad biológica, resistencia química y esfuerzos mecánicos a los que estará sometido el soporte de la BVC. Se evalúa la procesabilidad del material con tecnologías de fabricación rápida de prototipos, así como mediante técnicas de extrusión, maquinado o inyección de termoplásticos...