Removal of disease such as atherosclerotic plaque, thrombus and other types of obstructions and partial obstructions from internal body lumens or cavities using advanceable, rotating operating heads having cutter assemblies or abrasive materials is a well-established interventional technique. Numerous interventional catheters have been conceived and developed. Most of these systems require placement of a guide wire and guiding catheter prior to introduction of the interventional catheter and placement of the interventional catheter at the target operating site. Many of these prior art systems incorporate vacuum aspiration systems to remove the ablated material from the site, thereby preventing distal embolization. Some interventional catheters additionally or alternatively incorporate or are used in conjunction with other mechanisms, such as distal filters, for preventing removed material from circulating in the blood stream. Numerous interventional catheters also provide infusion of a liquid to the site of the intervention. Infused liquids may assist in the material removal process, or may be provided as diagnostic or therapeutic materials prior to, during or following an intervention.
Devices for collecting undesired material from a site in a body lumen or cavity, such as a blood vessel, that employ material excision devices incorporating a blade, barb, screw, or another material capture mechanism, to draw material into a device cavity are also known. These material capture mechanisms may be provided on a non-rotating or a rotating operating head. Non-cutting and non-mechanical systems for removing material from body lumens and blood vessels, such as heat, ultrasound and laser ablation systems, have also been developed.
Despite the many and varied approaches to the material removal systems, many challenges remain in providing systems for removing material from a lumen, such as a blood vessel, safely and reliably and without causing complications. The safety and reliability of the system is manifestly critical. Recovery of debris generated during a material removal operation, or reducing the particle size of the debris to a particle size that will not damage blood vessels or produce embolic events, is essential. The flexibility and size of an interventional catheter are also important features. The system must be small enough and flexible enough to navigate through sometimes tortuous internal structures and passageways for placement at the target interventional site. Maintaining desired fluid infusion rates and pressures, system flexibility and effective aspiration capacity while withdrawing debris through a long, small diameter catheter presents numerous challenges.