The present invention relates to components and methods used for attaching implantable devices to muscular tissue. An exemplary use for the present invention would be to affix a ventricular assist device, and associated elements (together, a “VAD”), to the heart of a living subject.
The heart is sometimes incapable of providing sufficient pumping capacity to meet the needs of the body. The effects of this inadequacy can be alleviated by providing a VAD that includes one or more mechanical pumps that supplement the pumping action of the heart. Each pump, like all other elements of the VAD, is preferably implantable in the living subject to supplement or replace the pumping action of the heart for an extended period of time. In some cases, the subject may have a VAD implanted for years while awaiting a suitable donor for a heart transplant.
A VAD usually has an inlet connected to the left ventricle. Most VADs have an outlet tube which is connected to the aorta. During operation, the VAD assists the heart to pump blood from the left ventricle to the aorta. In a typical case, the VAD is connected to the heart through the use of a mounting ring, as disclosed in U.S. Published Patent Application Nos. 2004/0171905 and 2007/0134993, the disclosures of which are hereby incorporated herein by reference.
In many cases, the mounting ring is fastened to the exterior of the heart. Each mounting ring typically has a hole that is placed over a corresponding hole formed in a wall of the heart. The VAD may then be secured to the mounting ring so that the VAD inlet extends into heart through respective holes in the mounting ring and the wall of the heart.
Sutures are commonly used to anchor the mounting ring to the heart. The time required to suture the ring to the heart adds to the time that a patient must be kept under anesthesia. Because many patients requiring VADs are generally frail, this additional time requirement is a significant drawback. Other types of anchors have also been contemplated; including those disclosed U.S. application Ser. No. 14/519,850, the disclosure of which is hereby incorporated herein by reference. Further improvements are required.
Despite their intended long life, a VAD, or elements of the VAD, may need to be replaced or upgraded before the patient is able to receive a donor heart. This may require the mounting ring, for example, to be detached from the heart. Some known anchoring means, such as sutures, can also be time-consuming or difficult to remove. This yet additional time requirement may also increase the health risks associated with the removal procedure. Further improvements are required to resolve these issues as well.