Systems for establishing supplemental blood flow in the circulatory system

#This invention generally relates to medical devices and methods and, more particularly, to methods and devices for fluid coupling to the heart of a patient in systems for assisting blood circulation in a patient.

#Various devices and methods have been utilized to conduct blood from the heart to assist with blood circulation in a patient. This is often desirable or necessary in cases where a patient is experiencing congestive heart failure and a transplant organ has either not been located, or the patient is not a suitable candidate for a transplant. The blood pumps are typically attached directly to the left ventricle of the heart, however, at least one blood pump system locates the pump remotely, such as subcutaneously in the manner of a pacemaker. In this regard, see U.S. Pat. No. 6,530,876, the disclosure of which is hereby fully incorporated by reference herein. In this situation or similar situations, a cannula may be used to create an inflow conduit from the heart (an intra-thoracic location) to a pump located in a superficial (non-thoracic cavity) location, which may be the so-called “pacemaker pocket.” Of course, other remote locations are possible as alternatives. The pacemaker pocket is a location usually accessed by a surgical incision generally parallel to and below the collarbone extending down toward the breast, and over the pectoral muscle. Sometimes the pacemaker pocket is made below the muscle. The pump, to which the cannula is connected, is intended to sit in the pectoral pocket and is preferably at, but not limited to, a location on the right side of the chest.

#One area in need of improvement is the insertion device, or trocar, used to deliver an inflow conduit or cannula to the heart. It would be desirable to provide an insertion device configured to give a surgeon enhanced control of the location of the tip of the insertion device to minimize trauma to the heart tissue during the process of inserting the tip of the insertion device through an incision or other opening in the heart tissue and into a chamber of the heart and to simplify this procedure resulting in a reduction in surgery time. It would also be desirable to provide an insertion device that may be securely engaged with the inflow cannula during insertion of the cannula into a chamber of the heart, and then disengaged from the cannula for removal.

#FIG. 1 is a schematic representation of chest anatomy, and illustrates one example of a pathway, exterior to the venous system, used to access a patient's heart and implant a circulatory assist system in accordance with an embodiment of the invention.

#FIG. 2 is a cross-sectional view of an inflow cannula with an insertion device according to an embodiment of the present invention extending through a lumen of the inflow cannula, and with an inflatable member of the insertion device inflated to releasably secure the insertion device to the inflow cannula.

#FIG. 3A is a cross-sectional view taken along line 3A-3A in FIG. 2A with the inflatable member of the insertion device inflated.

#FIG. 1 illustrates one of many possible general configurations of a blood circulation assist system 10 implanted in accordance with the inventive aspects. Devices and systems configured in accordance with the teachings herein may be implanted in any suitable surgical manner, including but not limited to those discussed generally herein, and may be used to insert a cannula through heart tissue into a chamber of the heart. Devices and systems configured in accordance with the inventive aspects may also be used to insert a cannula through other biologic tissue, for example through kidney tissue into an interior chamber of the kidney.

#System 10 includes an inflow cannula 12 that includes a distal end portion 12a that passes into the left atrium 14 of the heart 15 of patient 20. Access may be made, for example, into any portion within the left side of the heart (e.g., the left atrium and/or left ventricle) to access oxygenated blood. The inflow cannula 12 is attached directly to an exterior wall of the heart 15 on the left side, such as to the left atrial wall 14a as shown in FIGS. 7F-7G. The inflow cannula 12 may be directed to the exterior area of the heart through any desired surgical approach, such as one of the approaches generally discussed subsequently. Cannula 12 includes a distal anchor element 22 and a proximal anchor element 24 that have a disc-like configuration in the illustrative embodiment. However, anchor elements 22, 24 can have other configurations, such as illustrated in previously referenced U.S. Patent Application Ser. No. 60/823,971. Cannula 12 may be made of various implant or medical grade materials, such as silicone.

#The blood circulation assist system 10 also includes a blood pump 30, having an inlet 32 and an outlet 34, and an outflow cannula 36. A proximal end portion 12b of inflow cannula 12 is coupled to the inlet 32 of blood pump 30. Any suitable blood pump 30 may be used, including those described in U.S. Pat. Nos. 6,176,848; 6,116,862; 6,942,611; and 6,623,475 or DE 10 2004 019 721.0. The outflow cannula 36 is connected between the outlet 34 of the pump 30 and an artery, such as the superficial axillary artery 40. Blood flow therefore travels in the direction of the arrows 42 from the left atrium 14, through the pump 30, and into the patient's arterial system through the outflow cannula 36. The outflow cannula 36 may be connected to a superficial artery, such as the axillary artery 40, through a suitable surgical incision and attachment procedure which may involve the use of suitable grafts (not shown) and suturing (not shown).