Biomechanics of Transcatheter Aortic Valve Replacement Complications and Computational Predictive Modeling.

Transcatheter aortic valve replacement (TAVR) is a rapidly growing field enabling replacement of diseased aortic valves without the need for open heart surgery. However, due to the nature of the procedure and nonremoval of the diseased tissue, there are rates of complications ranging from tissue rupture and coronary obstruction to paravalvular leak, valve thrombosis, and permanent pacemaker implantation. In recent years, computational modeling has shown a great deal of promise in its capabilities to understand the biomechanical implications of TAVR as well as help preoperatively predict risks inherent to device-patient-specific anatomy biomechanical interaction. This includes intricate replication of stent and leaflet designs and tested and validated simulated deployments with structural and fluid mechanical simulations. This review outlines current biomechanical understanding of device-related complications from TAVR and related predictive strategies using computational modeling. An outlook on future modeling strategies highlighting reduced order modeling which could significantly reduce the high time and cost that are required for computational prediction of TAVR outcomes is presented in this review paper. A summary of current commercial/in-development software is presented in the final section.

Indigenously developed close delivery system for oral iodine-131 therapy: Nominal cost but phenomenal protection.

BACKGROUND: Administration of radiopharmaceuticals through intravenous and oral routes is the major source of radiation exposure to nuclear medicine (NM) technologists. Adopting new strategies to minimize radiation exposure is an important step toward safe practice in nuclear pharmacy. MATERIALS AND METHODS: We have indigenously developed a relatively close delivery system for oral administration of radioiodine-131 ((131)I) to minimize radiation exposure to the technologists. RESULTS: The efficacy of this indigenously developed close system was assessed upon 23 patients who were given (131)I therapies for benign (13 patients) and malignant thyroid disorders (10 patients). There was 64 ± 6% (P < 0.05) reduction in exposure rate using indigenously developed delivery system. CONCLUSION: The cost involved in developing this system was very nominal, but efficacy in terms of radiation safety and confidence of our technologists were phenomenal.