Abstract: The invention provides methods and devices for treating liver cirrhosis or portal hypertension by creating an intrahepatic shunt, or new passage, from a portal vein of a patient to a hepatic vein using a device with intravascular imaging capabilities and pressure sensing capabilities or positioning mechanisms. The integration of intravascular imaging aids in the precise placement of the shunt and pressure measurement may verify successful shunt creation. An apparatus may include a catheter with an extended body for insertion into a hepatic vein of a patient, an intravascular imaging device and a needle exit port on the distal portion of the extended body, and a needle disposed within a lumen in the catheter and configured to be pushed out of the exit port and extend away from a side of the extended body, in which the needle includes a pressure sensor.

Abstract: The invention relates to evaluation of maturity of arteriovenous (AV) fistula using guidewires that measure intravascular blood flow and/or pressure. The invention provides methods of evaluating AV fistula maturation using an instrumented guidewire to measure intravascular flow and/or pressure. By using a small diameter guidewire that does not interfere substantially with the flow, an accurate measurement can be made that is useful for identifying when a fistula is mature and therefore ready to be used for hemodialysis. The flow of blood through the fistula is measured using the guidewire and the measured flow and/or pressure of blood is used to determine if the fistula is mature.

Abstract: The invention generally relates to intraluminal procedures, and, more particularly, to a catheter assembly and methodology for creating a vascular access site between vessels. The invention provides a catheter assembly configured for percutaneous introduction into and extension through a blood vessel and further configured to create a vascular access site between two closely associated vessels. The catheter assembly includes at least one catheter having both intraluminal imaging capabilities and the ability to create a vascular access site on-demand within a vessel.

Abstract: The invention relates to restricting flow through a vascular access site such as an arteriovenous (AV) fistula or a graft using intravascular measurements to guide the procedure. The invention provides systems and methods for using intravascular detection to guide the restriction of flow through an AV fistula or graft. An intravascular instrument such as an imaging catheter or guidewire with measuring capabilities is inserted into a vessel proximal to an access site and used to evaluate the access site, which is banded to obtain healthy flow as indicated by the intravascular instrument. In certain aspects, the invention provides a method for improving a hemodialysis fistula or graft by inserting an intravascular instrument into a vessel proximal to the fistula or graft, making a measurement with the intravascular instrument, and restricting flow through the fistula or graft until the measurement obtains a predetermined value.

Abstract: The present invention generally relates to methods for assessing and treating dysfunctional vascular access sites, such as fistulas and grafts. According to certain aspects, methods of the invention include processing intraluminal image data of a vascular access site to characterize biological material present at the vascular access site, assessing the characterized biological material to identify a condition; and determining a therapeutic mode for treating the condition based on the assessment.

Abstract: The invention generally relates to catheter systems and methods for guided formation of vascular access sites (such as fistulas and grafts). According to certain aspects, a catheter system for forming a vascular access site include an elongate body comprising a distal end and configured to be inserted into a first vessel. The elongate body includes an exit port along its side that is proximal to the distal end. An imaging assembly is associated with the elongate body and configured to generate image data of the first vessel and a second vessel positioned next to the first vessel. For vascular access formation, a penetrating member of the catheter system extends out of the exit port and through a wall of the first vessel and a wall of the second vessel.

Abstract: The invention provides methods and systems for increasing the open cross-section of a vascular fistula that is obstructed by thrombus. Using a catheter having an imaging element and a thrombus disrupting element, the thrombus can be disrupted and removed, and the fistula evaluated with the imaging element. The imaging element is preferably an ultrasound imaging element.

Abstract: What is described is an apparatus for intravascular pressure measurement, comprising an elongate body and a first pressure sensor. The elongate body includes a proximal portion and a distal portion, the body defines a lumen extending from a proximal end to a distal end of the body, the lumen is sized and shaped to allow the passage of a guidewire therethrough, and the body includes an annular wall extending from the lumen to an outer surface of the body. The first pressure sensor is disposed entirely within the wall of the distal portion of the body, and the pressure sensor includes a sensor cover coupled to the wall. An exterior surface of the sensor cover and the outer surface of the body are substantially aligned.

Abstract: The invention provides methods for diagnosing and treating deep vein thrombosis and other conditions associated with occluded or constricted vessels. According to certain aspects, methods of the invention involve inserting a sensing device into a vessel having a thrombus therein, assessing, with the sensing device, one or more functional parameters within the vessel, determining an interventional therapy for treating the thrombus based on the assessing step; and performing the interventional therapy.