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Endograft fenestration using a radiofrequency wire for embolization of type 2 endoleaks.
No full textType II endoleaks are a common occurrence after endovascular repair of aortic aneurysm, with a significant subset requiring treatment. There are a significant subset of type II endoleaks that are not amenable to established treatment routes, such as transarterial, transcaval, or translumbar. We report two cases of a successful transgraft approach to type II endoleak embolization using the Powerwire radiofrequency guidewire. The use of the radiofrequency guidewire to accomplish transgraft embolization has not been previously reported. This is a useful technique to have in the arsenal for treating type II endoleaks
A Quality Improvement Project to Optimize Nurse Communication and Satisfaction Through Standardized L&D- Postpartum Handoffs
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Operating Room Maternal Preparation for Routine Cesarean Sections: Standardization of Circulating RN Education
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Induced current effects on functional magnetic resonance imaging interpretability during monopolar deep brain stimulation.
No full textOBJECTIVE: The objective was to evaluate the stability of stimulation current delivered by deep brain stimulation (DBS) systems during MRI scanning and to assess whether configuration-dependent variability in induced current may undermine the interpretability of functional MRI (fMRI) acquired during active stimulation.
METHODS: The authors measured the electrical output of 2 current-controlled DBS systems in a standardized phantom during 3-T MRI acquisition. Stimulation was delivered in both monopolar and bipolar configurations, with the DBS systems on and off. Induced current was recorded using a custom MRI-conditional setup, and peak amplitudes were quantified across multiple sequences, including gradient-intensive fMRI protocols. All data were normalized to baseline output and analyzed using Cohen\u27s d to assess the magnitude of MRI-induced current deviation.
RESULTS: Monopolar stimulation during MRI exhibited significant current fluctuations, with induced amplitudes ranging from -3.2 to +3.9 mA and frequent polarity inversion. These distortions were sequence dependent and most pronounced during fMRI acquisition. In contrast, bipolar stimulation demonstrated stable output with minimal deviation from programmed parameters. The variability observed in monopolar output was not attributable to impedance shifts and was consistent across both DBS systems tested.
CONCLUSIONS: MRI-induced current substantially alters the effective output of monopolar DBS, introducing uncertainty into any concurrent fMRI acquisition. Although functional imaging was not directly performed in human subjects, these findings imply that the observed blood oxygen level-dependent (BOLD) response during monopolar stimulation likely reflects the distorted, not programmed, stimulation. Bipolar configurations avoid this confounder and should be preferred when interpreting fMRI data acquired during DBS
