Primera colocación del dispositivo AMPLATZER™, Amulet™ para cierre de orejuela en Costa Rica utilizando Heart Navigator / First placement of the AMPLATZER™ Amulet™ device for appendage closure in Costa Rica using Heart Navigator

RESUMEN El cierre de la orejuela izquierda mediante un dispositivo facilita la prevención de un accidente cerebrovascular en pacientes con antecedente de fibrilación auricular no valvular y contraindicación para el uso de medicamentos anticoagulantes. Este artículo presenta dos casos de pacientes con historia de fibrilación auricular en el Hospital Calderón Guardia, ambos con el antecedente de sangrado digestivo y contraindicación para la anticoagulación, en los que se logró el cierre de la orejuela izquierda mediante la colocación exitosa del dispositivo AmuletTM, utilizando TAC y Heart Navigator, técnicas de imagen que se están convirtiendo en el estándar de oro de muchos centros internacionales de referencia en cardiología intervencionista.

ABSTRACT Closure of the left atrial appendage with a device facilitates the prevention of stroke in patients with a history of nonvalvular atrial fibrillation and a contraindication to the use of anticoagulant medications. This article presents two cases of patients with a history of atrial fibrillation at the Calderón Guardia Hospital, both with a history of digestive bleeding and contraindication to anticoagulation, in whom closure of the left atrial appendage was achieved through successful placement of the AmuletTM device, using CT and Heart Navigator, imaging techniques that are becoming the gold standard in many international reference centers in interventional cardiology.

CAD/CAM splint based on soft tissue 3D simulation for treatment of facial asymmetry / 대한악안면성형재건외과학회지

BACKGROUND: Most cases of facial asymmetry involve yaw deformity, and determination of the yaw correction level is very difficult. METHODS: We use three-dimensional soft tissue simulation to determine the yaw correction level. This three-dimensional simulation is based on the addition of cephalometric prediction to gradual yaw correction. Optimal yaw correction is determined visually, and an intermediate splint is fabricated with computer-aided design and computer-aided manufacturing. Application of positioning devices and the performance of horseshoe osteotomy are advisable. RESULTS: With this procedure, accurate repositioning of jaws was confirmed and patients obtained fairly good facial contour. CONCLUSIONS: This procedure is a promising method for a widespread, predictable treatment of facial asymmetry.

LOCALIZACIÓN DE FOCOS ECTÓPICOS DURANTE FIBRILACIÓN AURICULAR PERMANENTE, MEDIANTE UN NUEVO ÍNDICE OHF. ESTUDIO DE SIMULACIÓN / ECTOPIC FOCI LOCATION DURING PERMANENT ATRIAL FIBRILLATION USING A NEW INDEX OHF. A SIMULATION STUDY / LOCALIZAÇÃO DE FOCOS ECTÓPICOS DURANTE FIBRILAÇÃO ATRIAL PERMANENTE EM UM NOVO ÍNDICE OHF. ESTUDO DE SIMULAÇÃO

La fibrilación auricular (FA), en ciertos casos, es mantenida por focos ectópicos de actividad automática, organización espacio temporal y de alta frecuencia. La ablación de estos sitios da como resultado la terminación de la FA en un alto porcentaje en paciente con FA paroxística, sin embargo, en pacientes con FA permanente estos sitios son difíciles de reconocer debido a la capacidad de las aurículas remodeladas para ser activadas a altas frecuencias. Es necesario un método más preciso para acotar mejor estas zonas. En el presente trabajo se plantea desarrollar un nuevo índice, a partir de los índices de frecuencia dominante (DF) e índice de organización (IO), para la identificación de estas zonas. Para esto, se simularon episodios de FA permanente mantenidos por focos ectópicos de actividad continua en tres diferentes regiones, implementando un modelo 3D de aurícula humana. Se obtuvieron electrogramas en toda la superficie auricular y se calculó su DF and IO. El índice OHF (Organization High Frequency), se calculó como el producto entre el valor de la DF y del IO de cada uno de los electrogramas y se crearon mapas de falso color sobre el modelo 3D. Los resultados muestran que el índice OHF es capaz de identificar el foco ectópico de actividad continua durante episodios de FA permanente simulados.

Atrial fibrillation in some cases is maintained by ectopic foci with automatic activity, spatiotemporal organization and high frequency. Ablating these sites results in the AF termination in a high percentage of patients with paroxysmal AF, however, in patients with permanent AF these sites are difficult to recognize due to the ability of the remodeled atria to be activated at high frequencies. A more accurate method is needed to delimit better these areas. In the present work, we developed a new index, based on dominant frequency (DF) and organization index (OI), to identify these areas. For this, we simulated permanent AF episodes maintained by ectopic foci with continuous activity in three different regions, implementing a 3D model of human atrium. Electrograms were obtained across the atrial surface and its DF and IO were calculated. The OHF index (Organization High Frequency), was calculated as the product of the DF and IO values of individual electrograms and we created false color maps in the 3D model. The results show that the OHF index is able to identify ectopic foci of continuous activity during simulated permanent AF episodes.

A fibrilação atrial (FA), em alguns casos, é mantida por focos de actividade ectópica automático, organização e espaço de alta frequência temporal. Ablação desses locais determina a resolução da FA em uma alta porcentagem de pacientes com FA paroxística, no entanto, em pacientes com fibrilação atrial permanente desses sites são difíceis de reconhecer devido à capacidade dos átrios remodelado para ser ativado em alta frequências. Essas áreas para melhor abordagem é necessário um limite mais preciso. Neste artigo propõe-se a desenvolver uma freqüência novos índices com base em índice dominante (DF) e índice de organização (OI) para a identificação dessas áreas. Para isso, episódios de FA permanente mantido por focos ectópicos de atividade contínua em três regiões diferentes, implementando um modelo 3D de átrios humanos foram simulados. Eletrocardiogramas foram obtidos ao longo da superfície auricular e calculado o DF e IO. O OHF (Organização High Frequency) índice foi calculado como o produto do valor do DF e IO de eletrocardiogramas individuais e falsos mapas de cores do modelo 3D é criado. Os resultados mostram que o índice de OHF é capaz de identificar o foco ectópico de actividade contínua durante episódios de FA permanentes simulados.

3D Simulation of New Sacroliliac Internal Fixation System and Comparing Evaluation / 医用生物力学

Objective Creating a 3D finite element model of a full pelvis with sacroiliac joint fracture. Comparing the biomechanical properties of the model where the fracture part was fixated by using a new sacroliliac anatomy type Bar-plate internal fixation system to iliosacral screw fixation and front reconstruction plate fixation. Methods A specially designed biomechanical semi-automatic mesh generator was employed to generate the complete pelvis finite element model from CT datas. Then, one side of sacroiliac joint related ligaments was deleted to simulate the case of sacroiliac joint fracture. Using a new sacroliliac bar-plate internal fixation system with anatomic plate (SABP) to fix the fracture part, and the comparing models using iliosacral screw fixation (SS) and front reconstruction plate fixation (SP) were also generated. Finally, all models were simulated under same loading conditions. Results Using SABP fixation, the maximal displayment of the sacroiliac joint decreases about 40% and 42% compared to SS fixation and SP fixation, respectively. The minimal value of maximal stress for main loading transfer regions was reached by SABP fixation and t he maximal stress of SABP decreases about 33%-70% compares to SS in regions of fracture hip cortical bone and cartilages bone, and decreases about 60%-75% to SP in regions of sacral cortical bone and fracture hip cortical bone. Conclusion The new sacroliliac anatomy type Bar-plate internal fixation system has better biomechanical properties than other internal fixations, and deserves to be put into clinical application.