Abstract: Apparatus and methods are described including a blood pump catheter that includes an axial shaft, and an impeller disposed on the axial shaft. A motor drives the impeller to pump blood, by rotating the impeller. A drive cable extends from the motor to the axial shaft, the drive cable being configured to impart rotational motion from the motor to the impeller by rotating. A distal tip portion is disposed at a distal end of the blood pump catheter. The drive cable, the axial shaft, and the distal tip portion define a continuous lumen therethrough from outside the subject's body to the distal end of the blood pump catheter. The continuous lumen facilitates insertion of the blood pump catheter into the subject's body over a guidewire, and, subsequently, provides a channel through which the purging fluid flows. Other applications 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.

Abstract: Apparatus and methods are described, including a blood pump that includes a catheter, a proximal impeller disposed on the catheter inside a proximal impeller housing, and which is configured to pump blood by rotating inside the proximal impeller housing. A distal impeller is disposed on the catheter inside a distal impeller housing, distally to the proximal impeller, and the distal impeller is configured to pump blood by rotating inside the distal impeller housing. A tubular element is disposed between the proximal impeller housing and the distal impeller housing, the tubular element being configured to have a tubular configuration during rotation of the proximal and distal impellers. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump that includes a catheter, a first impeller disposed on the catheter, and a second impeller disposed on the catheter, proximally to the first impeller. A control unit drives the first and second impellers to pump blood of a subject, by driving the first and second impellers to rotate. The blood pumps is configured such that (a) the first and second impellers are shaped differently from each other when the first and second impellers are in non-radially-constrained configurations, (b) the first and second impellers are sized differently from each other when the first and second impellers are in non-radially-constrained configurations, and/or (c) the first and second impellers are driven by the control unit to rotate under respective rotation conditions that are different from each other. Other applications are also described.

Abstract: Apparatus and methods are described including coupling a rigid tube to a drive cable that comprises a plurality of coiled wires, by placing ends of the drive cable and the rigid tube at a given location within a butt-welding overtube. The ends of the drive cable and the rigid tube are visible when they are disposed at the given location within the butt-welding overtube, via a window defined by the butt-welding overtube. The placement of the drive cable within the butt-welding overtube is such that a helical groove within a portion of the butt-welding overtube is disposed over the drive cable. Welding rings are formed around the butt-welding overtube. 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 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 a blood pump that includes an impeller configured to pump blood through a subject's body, and a frame disposed around the impeller. The frame defines struts having a structure that is such that, as the frame transitions from a proximal end of the frame toward a center of the frame, the struts pass through junctions, at which the two struts branch from a single strut, in a Y-shape. The structure of the struts of the frame is configured such that, in response to a distal end of a delivery catheter and the frame being moved into overlapping positions with respect to each other, the frame assumes a radially-constrained configuration by becoming axially elongated, and the frame causes the impeller to assume a radially-constrained configuration by becoming axially elongated. Other applications are also described.

Abstract: Apparatus and methods are described including manufacturing an impeller by forming a structure having first and second bushings at proximal and distal ends that are connected to one another by at least one elongate element. The elongate element is made to radially expand and form a helical elongate element. An elastomeric material is coupled to the helical elongate element, such that the helical elongate element with the elastomeric material coupled thereto defines a blade of the impeller. The coupling is performed such that a layer of the material disposed around a radially outer edge of the helical elongate element forms the effective edge of the impeller blade. A step is performed to enhance bonding of the elastomeric material to the helical elongate element in a manner that does not cause a protrusion from the effective edge of the impeller blade. 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 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 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 a catheter (20), a first pump (24U) disposed on the catheter, and a second pump (24D) disposed on the catheter, proximally to the first pump. A control unit (52) is configured to control activation of the first and second pumps. The first and second pumps are configured, when activated, to pump fluid in opposite directions from one another. Other applications are also described.

Abstract: Apparatus and methods are described for improving renal function of a patient, including mechanically occluding the patient's inferior vena cava downstream of the renal vein ostium to form an upstream region and a downstream region of the inferior vena cava, and mechanically pumping blood through the inferior vena cava from the upstream region to a discharge location in the downstream region while the inferior vena cava is occluded, wherein the blood remains in the inferior vena cava while being mechanically pumped. Other applications are also described.

Abstract: Apparatus and methods are provided including a mitral valve prosthesis. The prosthesis includes an inner support structure having downstream and upstream sections, the upstream section having a cross-sectional area greater than the downstream section. The inner support structure is configured to be positioned on an atrial side of the native valve complex, and to prevent the prosthesis from being dislodged into the left ventricle. A prosthetic valve having prosthetic valve leaflets is coupled to the inner support structure. An outer support structure has engagement arms, downstream ends of the engagement arms being coupled to the inner support structure. The prosthesis is configured such that, upon implantation thereof: downstream ends of the native valve leaflets, downstream ends of the engagement arms, and downstream ends of the prosthetic leaflets, are disposed at a longitudinal distance from one another of less than 3 mm. Other embodiments are also described.

Abstract: Apparatus and methods are provided including a mitral valve prosthesis. The prosthesis includes an inner support structure having downstream and upstream sections, the upstream section having a cross-sectional area greater than the downstream section. The inner support structure is configured to be positioned on an atrial side of the native valve complex, and to prevent the prosthesis from being dislodged into the left ventricle. A prosthetic valve having prosthetic valve leaflets is coupled to the inner support structure. An outer support structure has engagement arms, downstream ends of the engagement arms being coupled to the inner support structure. The prosthesis is configured such that, upon implantation thereof: downstream ends of the native valve leaflets, downstream ends of the engagement arms, and downstream ends of the prosthetic leaflets, are disposed at a longitudinal distance from one another of less than 3 mm. Other embodiments 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 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 identifying a subject as suffering from cardiac dysfunction, congestive heart failure, reduced renal blood flow, increased renal vascular resistance, arterial hypertension, and/or kidney dysfunction, and, in response thereto, reducing blood pressure within a renal vein of the subject, by activating at least one impeller to pump blood from the renal vein into a vena cava of the subject, by the impeller rotating.