Abstract: One embodiment of the invention incudes a single cylinder zigzag strut Z stent cylinder fixedly joined to a braided stent such that a portion of the joined Z stent cylinder extends beyond the termination end of the braided wire stent. The Z stent cylinder can have a larger in diameter than the braided stent when expanded.

Abstract: A method of measuring column interruption duration in a selected lower leg vein of a patient without undertaking dorsal foot measurements. The method includes the step of selecting a vein in the lower leg to be examined and selecting a valve in the vein to be observed. The valve's actions will be observed with Duplex ultrasound and timed. The method then effects calf muscle ejection and observing the action of the selected valve in the respective vein selected. The valve can be observed for opening or closing action, or action of blood flow (or lack of flow) through the valve. The CID is then determined calculated based on the timing of events observed with ultrasound. The ultrasound can be Duplex ultrasound; invasive measurements are not required.

Abstract: The invention includes an expandable stent having a tubular shape when expanded, the shape including a portion t where the stent radius grows with stent length so that the growth in the portion is constant conductance growth or near-constant conductance growth. The invention includes sheaths that will encase the stent to restrict the growth of the stent to the desired expanded shape. The invention also includes expandable stent balloons that expand the stent to the desired shape configuration with constant or near constant conductance portion. The balloons can include a similar sheath or sleeve to restrict the balloon's growth to the desired shape. The stent radius growth can be piecewise, and is not necessarily 4th order growth, but can be such that rn/l is a constant in the portion, where n>4.

Abstract: The invention includes modifications of a Z stent to allow the top struts of two Z stents deployed in the vena cava in a bilateral relationship, to interleave. One embodiment includes Z stents with angled top surfaces. A second embodiment includes Z stents having an intermediary suture but lacking the top suture in the topmost stent of a stacked stent module.

Abstract: The invention includes an improved flow graft. The graft has a portion where the radius r expands with length L over the portion, so that rn/L is a constant in that portion, where n?4.0, or 1<n<4. It is preferred that the graft has a beginning section that has constant diameter. The invention also includes a method of designing such an expanding graft to suit the application, such as in the venous system, the arterial system, or for dialysis. The invention also includes near constant conductance stents whose radius r can grow with length, so the Rn/L is constant where n>4.

Abstract: An improved flow conduit with gradually expanding caliber is described, where the conduit radius r grows with conduit length 1 so that the conductance remains constant or r4/l is constant, or alternatively, where the flow is near constant conductance flow, where or rn/l is constant, where n>4. The radius can expand over a portion of the conduit.

Abstract: Thrombectomy systems and devices and methods of using the same. In an exemplary embodiment of a thrombectomy system of the present disclosure, the thrombectomy system comprises a thrombectomy sheath, comprising a circumferential outer wall reinforced with a reinforcement, configured as an elongated tube having a lumen therethrough; and a sonovisible element positioned at or near a distal end of the circumferential outer wall; wherein the thrombectomy sheath is sized and shaped to be at least partially positioned within a vein proximal to a thrombus or other item within the vein and further configured to expand to contact the vein to secure the thrombectomy sheath within the vein; and wherein the lumen is sized and shaped to receive a device selected from the group consisting of a balloon catheter and a snare having a loop.

Abstract: Thrombectomy systems and devices and methods of using the same. In an exemplary embodiment of a thrombectomy system of the present disclosure, the thrombectomy system comprises a thrombectomy sheath, comprising a circumferential outer wall reinforced with a reinforcement, configured as an elongated tube having a lumen therethrough; and a sonovisible element positioned at or near a distal end of the circumferential outer wall; wherein the thrombectomy sheath is sized and shaped to be at least partially positioned within a vein proximal to a thrombus or other item within the vein and further configured to expand to contact the vein to secure the thrombectomy sheath within the vein; and wherein the lumen is sized and shaped to receive a device selected from the group consisting of a balloon catheter and a snare having a loop.

Abstract: The invention includes an expandable stent having a tubular shape when expanded, the shape including a portion t where the stent radius grows with stent length so that the growth in the portion is constant conductance growth or near-constant conductance growth. The invention includes sheaths that will encase the stent to restrict the growth of the stent to the desired expanded shape. The invention also includes expandable stent balloons that expand the stent to the desired shape configuration with constant or near constant conductance portion. The balloons can include a similar sheath or sleeve to restrict the balloon's growth to the desired shape. The stent radius growth can be piecewise, and is not necessarily 4th order growth, but can be such that rn/l is a constant in the portion, where n>4.

Abstract: A method of measuring column interruption duration in a selected lower leg vein of a patient without undertaking dorsal foot measurements. The method includes the step of selecting a vein in the lower leg to be examined and selecting a valve in the vein to be observed. The valve's actions will be observed with Duplex ultrasound and timed. The method then effects calf muscle ejection and observing the action of the selected valve in the respective vein selected. The valve can be observed for opening or closing action, or action of blood flow (or lack of flow) through the valve. The CID is then determined calculated based on the timing of events observed with ultrasound. The ultrasound can be Duplex ultrasound; invasive measurements are not required.

Abstract: The invention includes modifications of a Z stent to allow the top struts of two Z stents deployed in the vena cava in a bilateral relationship, to interleave. One embodiment includes Z stents with angled top surfaces. A second embodiment includes Z stents having an intermediary suture but lacking the top suture in the topmost stent of a stacked stent module.

Abstract: The invention includes a method of determining when to stent in the iliac system. The optimal vein diameters of the CFV, EIV and CIV are predicted based on hydrodynamic consideration and Young's scaling law. The optimal vein cross-sectional area is then calculated from the optimal diameters, assuming a circular lumen. The technique then measures a suspect vein with 3D DUS and compares the DUS measured diameter or DUS calculated area with the optimal diameter and optimal area. When the comparison indicates that the measures is less than 90% of area, or 4.9 for the diameter, then a stenosis is indicated and IVUS used to confirm the diagnosis. The IVUS measured vein area is again compared to the optimal cross-sectional area, and if the measurement is less than a specific percentage, the diagnosis is confirmed and the vein is stented, using a stent of the optimal diameter plus 2 mm.

Abstract: Whether a vein has a stenosis may be determined using duplex ultrasound (DUS). A method of diagnosing stenosis includes: identifying a patient exhibiting at least one of a group of symptoms in at least one limb consisting of: pain, discomfort, swelling and venous stasis skin changes including ulceration; using duplex ultrasound to measure a cross-sectional area of a vein; and, if the cross-sectional area is less than or equal to 50% of a predetermined anatomical minimum for the vein, diagnosing the vein as stenotic. A device for diagnosing stenosis may include: a duplex ultrasound; a display; and a processor configured to show on the display a cross-sectional area measurement of a vein. Stenosis may be treated by inserting a stent in the vein. The predetermined anatomical minimum for the vein is a predetermined calculated valve based on physical principles. It is not a measured value from the patient, or any patient, or a population of patients.

Abstract: Thrombectomy systems and devices and methods of using the same. In an exemplary embodiment of a thrombectomy system of the present disclosure, the thrombectomy system comprises a thrombectomy sheath, comprising a circumferential outer wall reinforced with a reinforcement, configured as an elongated tube having a lumen therethrough; and a sonovisible element positioned at or near a distal end of the circumferential outer wall; wherein the thrombectomy sheath is sized and shaped to be at least partially positioned within a vein proximal to a thrombus or other item within the vein and further configured to expand to contact the vein to secure the thrombectomy sheath within the vein; and wherein the lumen is sized and shaped to receive a device selected from the group consisting of a balloon catheter and a snare having a loop.

Abstract: Thrombectomy systems and devices and methods of using the same. In an exemplary embodiment of a thrombectomy system of the present disclosure, the thrombectomy system comprises a thrombectomy sheath, comprising a circumferential outer wall reinforced with a reinforcement, configured as an elongated tube having a lumen therethrough; and a sonovisible element positioned at or near a distal end of the circumferential outer wall; wherein the thrombectomy sheath is sized and shaped to be at least partially positioned within a vein proximal to a thrombus or other item within the vein and further configured to expand to contact the vein to secure the thrombectomy sheath within the vein; and wherein the lumen is sized and shaped to receive a device selected from the group consisting of a balloon catheter and a snare having a loop.

Abstract: This invention is a modular intraluminal tubular stent system for deployment in the venous system and a method of stenting a vein segment using a modular stent system. One of the stents in the system includes a reinforced terminal end portion, such as a helical coil, to provide additional expansive force to maintain the initial deployed location of the stent. The coil may be interwoven into the wall of the stent, or a separate structure deployed separately.

Abstract: Thrombectomy systems and devices and methods of using the same. In an exemplary embodiment of a thrombectomy system of the present disclosure, the thrombectomy system comprises a thrombectomy sheath, comprising a circumferential outer wall reinforced with a reinforcement, configured as an elongated tube having a lumen therethrough; and a sonovisible element positioned at or near a distal end of the circumferential outer wall; wherein the thrombectomy sheath is sized and shaped to be at least partially positioned within a vein proximal to a thrombus or other item within the vein and further configured to expand to contact the vein to secure the thrombectomy sheath within the vein; and wherein the lumen is sized and shaped to receive a device selected from the group consisting of a balloon catheter and a snare having a loop.

Abstract: This invention is a modular intraluminal tubular stent system for deployment in the venous system and a method of stenting a vein segment using a modular stent system. One of the stents in the system includes a reinforced terminal end portion, such as a helical coil, to provide additional expansive force to maintain the initial deployed location of the stent. The coil may be interwoven into the wall of the stent, or a separate structure deployed separately.

Abstract: This invention is a modular intraluminal tubular stent system for deployment in the venous system. One of the stents in the system includes a reinforced terminal end portion, such as a helical coil, to provide additional expansive force to maintain the initial deployed location of the stent. The coil may be interwoven into the wall of the stent, or a separate structure deployed separately.

Abstract: A method of diagnosing an obstructive lesion in the iliac venous system. The method includes the steps of identifying the presence of chronic venous disease from clinical evaluation alone of a patient, and without any further evaluation, undertaking an IVUS procedure on the patient to identify any non-thrombotic or thrombotic iliac vein lesions.