ASPIRATION CATHETER (EMBODIMENTS) AND METHOD FOR PRODUCTION THEREOF Russian patent published in 2024 - IPC A61B17/22 A61M25/00 A61M25/16 

FIELD: medicine.

SUBSTANCE: invention relates to retrievable medical devices for removing blood clots from blood vessels of a patient to restore blood flow. In particular, the aspiration catheter can be used for revascularization in patients with acute ischemic stroke caused by intracranial vascular occlusion. Aspiration catheter includes a shaft and a luer connector. Shaft has a proximal end, a distal end, a longitudinal axis and a lumen bounded by the shaft wall. Shaft wall includes an outer layer, an inner layer and a reinforcing braid. Outer layer of shaft wall includes at least five sections located along longitudinal axis, made of polymers differing in hardness. Hardness of polymers, from which different sections of the outer layer of the shaft wall are made, decreases in the direction from the proximal end to the distal end of the shaft. Inner layer is made of polytetrafluoroethylene and has thickness of 6–20 mcm. Ratio of shaft opening diameter to shaft wall thickness is 10:1–14:1. At least part of outer surface of shaft wall has hydrophilic coating. According to a second embodiment of the aspiration catheter, the reinforcing braid is made of at least one continuous wire, spirally extending along shaft lengthwise axis between inner and outer layers of shaft wall. Spiral is characterized by a spiral pitch of 60–300 mcm. Reinforcing braiding includes 2–15 zones located along longitudinal axis and differing with spiral pitch, besides, zones with larger pitch of spiral are located proximally relative to zones with smaller pitch of spiral. Method of producing the above catheter versions includes the following steps: a) forming a reinforcing braid on top of a tube made of polytetrafluoroethylene; b) at least five tubes made of polymers differing in hardness are placed on top of the reinforcing braiding; c) the obtained structure is heated to temperature of 190–300 °C production of shaft; d) forming a hydrophilic coating on a part of the outer surface of the shaft wall.

EFFECT: creation of an aspiration catheter, characterized by high aspiration rate, optimal ratio of flexibility and rigidity, resistant to kink formation, having high smoothness of outer surface, capable of deep pushing inside winding blood vessels, as well as an important part of the technical result is the development of an accessible method for producing the disclosed aspiration catheter.

28 cl, 3 tbl, 11 dwg, 6 ex