Medical device and treatment method

#This application claims priority to Japanese Application No. 2016-023809 filed on Feb. 10, 2016, the entire content of which is incorporated herein by reference.

#The present invention generally relates to a medical device and a treatment method used to remove an object from a body lumen.

#A thrombus formed in a portion of a vein, for example, may cause pain or swelling, and this may be treated by removing the thrombus with a thrombus-removing device that is percutaneously inserted into the vein. In such a treatment, if the entirety or a portion of the thrombus that has been separated from the wall of the blood vessel is carried by blood flow and reaches the lungs, there is a risk that pulmonary embolism will occur. Therefore, when such a treatment is performed, a thrombolytic agent is used before, during, and/or after the treatment, or the separated thrombus is removed as thoroughly as possible by suction during the treatment. However, even when these processes are carried out, there is still a possibility that a separated thrombus that is dangerously large from a clinical point of view will reach, for example, the lungs.

#FIG. 1 is a plan view of a medical device according to an embodiment.

#FIG. 2 is a plan view of the medical device according to the embodiment illustrating the state in which an expanding unit, a pressing shaft, and a sheath are assembled.

#FIGS. 3A and 3B are plan views of a distal portion of the expanding unit, wherein FIG. 3A illustrates the state in which expanding members are expanded and FIG. 3B illustrates the state in which the expanding members are contracted.

#Set forth below with reference to the accompanying drawings is a detailed description of an embodiment of a medical device and treatment method representing examples of the inventive medical device and treatment method disclosed here. In the drawings, dimensional ratios may be exaggerated and differ from the actual dimensional ratios to facilitate an understanding of the disclosed device and method.

#A medical device 10 according to an embodiment representing one example of the disclosed medical device is used to obstruct flow in a blood vessel in order to remove an object, such as a thrombus or a plaque, from the blood vessel. In this specification, the side of the device from which the device is inserted into the blood vessel is referred to as the “distal side”, and the side of the device at which the device is operated is referred to as the “proximal side”. The object to be removed is not necessarily limited to a thrombus or a plaque, and may be any object that can exist in a body lumen (lumen in a living body). In this specification, the source side of the flow of blood in the blood vessel is referred to as the “upstream side”, and the destination side of the flow of blood is referred to as the “downstream side”.

#As illustrated in FIGS. 1 and 2, the medical device 10 includes an expanding unit 20 that obstructs the flow of blood in a blood vessel, a sheath 30 configured to accommodate the expanding unit 20, and a pressing shaft 40 for pushing the expanding unit 20 out of the sheath 30. To obstruct the flow of blood means to regulate or impede (stop or reduce) the blood flow by closing or narrowing the cross section of the blood vessel, wherein the cross section is perpendicular to the axis of the blood vessel.