Feasibility and Accuracy of Measuring Carotid Plaque Volume (Burden) With Contrast-Enhanced Tomographic 3D Ultrasound and Ultrasound Image Fusion.

BACKGROUND: Stenosis severity has been the indication for carotid endarterectomy (CEA) for 4 decades, but the annual stroke risk in asymptomatic carotid stenosis >70% is under 2%. Atherosclerotic volume has emerged as a risk factor for future stroke, but needs to be measured noninvasively. Tomographic ultrasound (tUS) is a novel technology that assembles 3D images in seconds. We evaluated accuracy of measuring Carotid Plaque Volume (CPV) with tUS in patients undergoing CEA. METHOD: Consecutive patients were imaged immediately before CEA by tUS and contrast-enhanced tUS (CEtUS). CPV was measured using tUS, CEtUS, and a fused images incorporating both tUS and CEtUS by trained vascular scientists. Precise volume of the endarterectomy specimen was measured using Archimedes technique. RESULTS: Mean ± sd (range) CPV in 129 endarterectomy specimens was 0.75 ± 0.43 cm3 (0.10-2.47 cm3). Mean ± sd CPV measured by tUS (n = 114) was 0.87 ± 0.51 cm3, CEtUS (n = 104) was 0.75 ± 0.45 cm3 and with fusion (n = 95) was 0.83 ± 0.49 cm3. Differences between specimen volume and CPV measured by tUS (0.13 ± 0.24 cm3), CEtUS (-0.01 ± 0.21 cm3) or fusion (-0.08 ± 0.20) were clinically insignificant. Intra-/interobserver differences were minimal. CONCLUSIONS: tUS accurately measures CPV with excellent intra-/interobserver agreement. CEtUS improves accuracy if precise CPV measurement is needed for research but tUS alone would be sufficient for population screening.

Posición rotacional del componente tibial en las artroplastias de rodilla. Estudio comparativo entre instrumentación estándar y cirugía asistida con ordenador / Rotational position of the tibial component in knee arthroplasties. Comparative study between standard instrumentation and computer-assisted surgery

Objetivo: Conocer las diferencias en la posición rotacional del componente tibial de las artroplastias de rodilla utilizando la navegación quirúrgica. Material y método: Estudio aleatorizado de dos grupos de artroplastias totales de rodilla: en 24 implantes mediante cirugía estándar con instrumentación mecánica y en 34 con un sistema de navegación quirúrgica inalámbrico. A los pacientes se les realizó una tomografía computada de rodilla y tobillo en el pre y en el postoperatorio para calcular la rotación tibial y la posición final de la artroplastia. Resultados: No se encontraron diferencias estadísticamente significativas en la rotación del implante tibial entre ambos grupos. En los pacientes del grupo de navegación la posición de la artroplastia en el eje frontal fue mejor que en el grupo estándar, pero no hubo diferencias en la rotación tibial. Conclusión: La navegación quirúrgica en las artroplastias de rodilla facilita la colocación del implante en el eje frontal pero no en el rotacional. Es posible que la navegación aporte más ventajas en rodillas con deformidades o cuando no puede utilizarse la instrumentación convencional por ocupación del canal intramedular (AU)

Objective: To establish the differences in the rotational position of tibial component in knee arthroplasties using surgical navigation. Material and methods: Randomized study of two groups of total knee arthroplasties: in 24 implants using standard surgery with mechanical instrumentation and 34 with a wireless surgical navigation system. Patients underwent computed tomography of the knee and ankle pre-and postoperatively to calculate tibial rotation and final position of the arthroplasty. Results: There were no statistically significant differences in rotation of the tibial implant between the two groups. In surgical navigation group patients, arthroplasty position in the frontal axis was better than in the standard group, but there were no differences in tibial rotation. Conclusion: Surgical navigation in knee arthroplasties facilitates placement of the implant in frontal axis but not rotational positioning. It is possible that the navigation provides more advantages in knees with deformities or when conventional instrumentation cannot be used due to occupation of the intramedullary canal (AU)