Abstract: Apparatus and methods are described including manufacturing an impeller by coupling a material to a helical elongate element, such that the helical elongate element with the material coupled thereto defines a blade of the impeller. A portion of a structure that includes the helical elongate element is dipped into the material while the material is in a liquid state. The material is dried, while the material is being supported by the at least one helical elongate element. During the drying of material, the structure is rotated about its longitudinal axis, such as to facilitate the formation of a film of the material having a substantially uniform thickness within the impeller blade. Other applications are also described.

Abstract: Apparatus and methods are described including manufacturing a housing for an impeller of a blood pump by placing an inner lining around a mandrel, placing a cylindrical portion of a frame around the inner lining, and placing a distal portion of an elongate tube around a portion of the frame. While the distal portion of the elongate tube is disposed around the portion of the frame, the inner lining, the frame, and the distal portion of the elongate tube are heated, via the mandrel, and pressure is applied from outside the distal portion of the elongate tube, such as to cause the distal portion of the elongate tube to conform with a structure of the struts of the frame, and to cause the inner lining and the distal portion of the elongate tube to become coupled to the frame. Other applications are also described.

Abstract: Apparatus and methods are described including an impeller that includes an impeller frame that comprises proximal and distal end portions and at least one helical elongate element that winds from the proximal end portion to the distal end portion. A film of material is coupled to the at least one helical elongate element, such that the helical elongate element with the film of material coupled thereto defines a blade of the impeller. The film of material is shaped to define a hollow central lumen therethrough. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump that is placed inside a body of subject. The blood pump includes an impeller that includes proximal and distal bushings, and that defines an axial lumen that extends from the proximal bushing to the distal bushing, a frame disposed around the impeller, and an axial shaft that passes through the proximal and distal bushings of the impeller. A distal end of a delivery catheter, and the frame and the impeller, are configured to be moved with respect to one another, to thereby cause the frame to assume a radially-constrained configuration by the frame becoming axially elongated, and cause the impeller to assume a radially-constrained configuration by the impeller becoming axially elongated. Other applications are also described.

Abstract: Apparatus and methods are described, including a catheter (20) configured to be placed inside a blood vessel of a subject. A first impeller (28) is disposed on the catheter, and a second impeller (28) is disposed on the catheter, proximally to the first impeller. A support structure (160) is disposed upon the catheter such that a longitudinal center of the support structure is disposed between the first and second impellers, the support structure being configured to support an inner wall of the blood vessel in an open configuration in a region between the first and second impellers. Other applications are also described.

Abstract: Apparatus and methods are described including a tube configured to traverse a subject's aortic valve. A frame is disposed within a portion of the tube, and a plurality of winged projections are coupled to the frame. An impeller is disposed inside the tube, the impeller including at least one helical elongate element, and a film of material supported at least partially by the helical elongate element. The impeller is rotated, such as to pump blood from the subject's left ventricle to the subject's aorta. Blood flow that is generated by the rotation of the impeller is rectified, by using the winged projections to direct blood flow toward a direction of the longitudinal axis of the tube. Other applications are also described.

Abstract: Apparatus and methods are described including a left-ventricular assist device that includes a tube configured to traverse a subject's aortic valve, with a distal portion of the tube within the subject's left ventricle. A frame disposed within the distal portion of the tube defines cells, and a width of each of the cells within a cylindrical portion of the frame is less than 2 mm. An inner lining lines at least some of the cylindrical portion of the frame. An impeller is disposed inside the frame such that a gap between an outer edge of the impeller and the inner lining is less than 1 mm. The impeller is stabilized with respect to the frame, such that, during rotation of the impeller, the gap between the outer edge of the impeller and the inner lining is maintained and is substantially constant. Other applications are also described.

Abstract: Apparatus and methods are described including a tube configured to traverse a subject's aortic valve. A frame is disposed within a portion of the tube, and an impeller is disposed inside the tube such that, when the impeller and the tube are deployed inside the subject, a gap between an outer edge of the impeller and an inner surface of the tube is less than 1 mm. The impeller rotates such as to pump blood from the left ventricle to the aorta, and is stabilized with respect to the tube, such that, during rotation of the impeller, the gap between the outer edge of the impeller and the inner surface of the tube is maintained. The impeller includes at least one impeller blade defined by a helical elongate element, and a film of material supported by the helical elongate element. Other applications are also described.

Abstract: Apparatus and methods are described including a left-ventricular assist device that includes a tube configured to traverse a subject's aortic valve, with a distal portion of the tube disposed within the subject's left ventricle. A frame is disposed within the distal portion of the tube. A pump disposed within the frame pumps blood through the tube. A distal-tip element defines a straight proximal portion that defines a longitudinal axis, and a curved distal portion that is shaped such as to curve in a first direction with respect to the longitudinal axis before passing through an inflection point and curving in a second direction with respect to the longitudinal axis, such that the curved distal portion defines a bulge on one side of the longitudinal axis. Other applications are also described.

Abstract: Apparatus and methods are described including placing, into a subject's body, a blood-pump tube, with a blood pump disposed within the blood-pump tube. At least one blood-pressure-measurement tube, which defines an opening at a distal end thereof, extends to at least an outer surface of the blood-pump tube, such that the opening at the distal end of the blood-pressure-measurement tube is in direct fluid communication with a bloodstream of the subject outside the blood-pump tube. Blood is pumped through the blood-pump tube, using the blood pump. Pressure of the bloodstream of the subject outside the blood-pump tube is measured by measuring pressure of blood within the blood-pressure-measurement tube. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump that includes an impeller that has proximal and distal bushings, and is configured to pump blood through a subject's body. A frame, which includes proximal and distal bearings, is disposed around the impeller. An axial shaft passes through the proximal and distal bearings of the frame and the proximal and distal bushings of the impeller. The axial shaft is coupled to at least one of the proximal and distal bushings of the impeller, such that the at least one bushing is held in an axially-fixed position with respect to the axial shaft, and is not held in an axially-fixed position with respect to the proximal and distal bearings. Other applications are also described.

Abstract: Apparatus and method are described including identifying a subject as suffering from a condition that causes the subject to have elevated central venous pressure. In response thereto, a device is placed inside the subject's vena cava such that an upstream end of the device is placed at a location upstream of junctions of the vena cava with all of the subject's renal veins. The device defines a passage through the device, at least a portion of the passage converging in a direction from an upstream end of the device to downstream end of the device. Other applications are also described.

Abstract: Apparatus and methods are described for use with a tributary vessel of a subject that supplies a vein of the subject. Blood within the tributary vessel is mechanically isolated into a compartment that is separated from blood within the vein. Blood flow from the tributary vessel to the vein is controlled by pumping blood from the compartment to the vein. Other applications are also described.

Abstract: Apparatus and methods are described including a tube (20) that defines a flared downstream portion (30) that diverges toward a downstream end (32) of the tube, and a flared upstream portion (26) that diverges toward an upstream end (28) of the tube, such that a central portion (34) of the tube is narrower than at the ends of the tube. The tube defines a plurality of lateral openings (36). A support frame (24) supports the tube within a subject's vena cava, such that the downstream portion is sealed with respect to the wall of the vena cava downstream of junctions of the vena cava with all of the subject's renal veins, and the upstream portion is sealed with respect to the inner wall of the vena cava upstream of junctions of the vena cava with all of the subject's renal veins. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump (24) configured to be placed inside a blood vessel of a in subject, the blood pump including an impeller (28) configured to pump blood by rotating. A support cage (254) is shaped to define a narrow portion (256) that is configured to be disposed around the impeller, and to maintain a separation between a wall of the blood vessel and the impeller, and a radial extension (258) from the narrow portion of the support cage that extends radially outward with respect to the narrow portion of the support cage, the radial extension being configured to substantially maintain a longitudinal axis of the impeller in alignment with a local longitudinal axis of the blood vessel by contacting the wall of the blood vessel. Other applications are also described.

Abstract: Apparatus and methods are described including placing an impeller of a ventricular assist device inside a left ventricle of a subject, with a frame disposed around the impeller. The impeller is driven to pump blood from the left ventricle to an aorta of the subject, by rotating the impeller. The impeller is placed inside the left ventricle such that the impeller is allowed to undergo axial motion with respect to the frame, in response to cyclical changes in a pressure difference between the left ventricle and the aorta. Other applications are also described.

Abstract: Apparatus and methods are described including placing a blood pump into a subject's body, the blood pump including an axial shaft, an impeller disposed on the axial shaft, and a drive cable extending from outside the subject's body to the axial shaft. The impeller is driven to pump blood from a distal end of the impeller to a proximal end of the impeller by imparting rotational motion to the impeller via the drive cable, in a given direction of rotation. At least a portion of the drive cable includes a plurality of wires disposed in a coiled configuration that is such that, in response to the drive cable rotating in the given direction of rotation, the plurality of wires disposed in the coiled configuration at least partially unwind, such that the portion of the drive cable shortens axially. Other applications are also described.

Abstract: An inferior vena cava (IVC) implant is provided that includes a tubular implant body, which is configured to assume a compressed delivery configuration and an expanded deployment configuration, and configured such that when implanted in the expanded deployment configuration in the IVC in the vicinity of the renal junctions, (a) has a generally tubular shape, (b) has upstream and downstream ends, and (c) is shaped so as to define: (i) two indentations on opposite sides of the tubular implant body, which are shaped so as to allow blood flow in the two indentations from upstream of the tubular implant body to downstream of the tubular implant body, and (ii) one or more surfaces that at least partially block blood flow through an interior of the tubular implant body from upstream of the tubular implant body to downstream of the tubular implant body. Other embodiments are also described.

Abstract: Apparatus and methods are described including a blood pump configured to be placed inside a body of subject, the blood pump including an impeller that includes proximal and distal bushings, and a frame disposed around the impeller, the frame including proximal and distal bearings. An axial shaft passes through the proximal and distal bearings of the frame and the proximal and distal bushings of the impeller. The impeller defines a radially-constrained configuration in which the impeller is introduced into the subject's body and a non-radially-constrained configuration in which the impeller is configured to pump blood within the subject's body. The impeller changes from its radially-constrained configuration to its non-radially constrained configuration by the distal bushing sliding over the axial shaft. Other applications are also described.

Abstract: Apparatus and methods are described including an impeller that includes an impeller frame that comprises proximal and distal end portions and at least one helical elongate element that winds from the proximal end portion to the distal end portion. A material is coupled to the at least one helical elongate element, such that the at least one helical elongate element with the material coupled thereto defines a blade of the impeller. A plurality of sutures are tied around the at least one helical elongate element, the sutures being configured to facilitate coupling of the material to the at least one helical elongate element. Other applications are also described.