Aspects of the present disclosure are directed toward catheter-based apparatuses, such as componentry utilized with or as part of catheters, or as catheters or catheter assemblies. As may be implemented in accordance with one or more embodiments, a method and/or apparatus involves a filter having a frame that forms a perimeter of the filter and separates opposing surfaces thereof. An articulated arm is connected to the frame and configured therewith to, when deployed within a tubular organ, engage with opposing inner sidewall portions of the tubular organ and to utilize the inner sidewall portions to seal filter to the inner sidewall by applying force to the frame.
