The present application claims the benefit of U.S. Provisional Application No. 61/492,135 filed Jun. 1, 2011, which is incorporated herein in its entirety by reference.
FIELD OF THE INVENTION
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The present invention relates to minimally invasive delivery of a suture. More particularly, the present invention relates to attaching the suture as an artificial chordae tendineae to a flailing or prolapsing leaflet in a beating heart via an intravascular ventricular septal approach.
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OF THE INVENTION
Various types of surgical procedures are currently performed to investigate, diagnose, and treat diseases of the heart and the great vessels of the thorax. Such procedures include repair and replacement of mitral, aortic, and other heart valves, repair of atrial and ventricular septal defects, pulmonary thrombectomy, treatment of aneurysms, electrophysiological mapping and ablation of the myocardium, and other procedures in which interventional devices are introduced into the interior of the heart or a great vessel.
Using current techniques, many of these procedures require a gross thoracotomy, usually in the form of a median sternotomy, to gain access into the patient's thoracic cavity. A saw or other cutting instrument is used to cut the sternum longitudinally, allowing two opposing halves of the anterior or ventral portion of the rib cage to be spread apart. A large opening into the thoracic cavity is thus created, through which the surgical team may directly visualize and operate upon the heart and other thoracic contents.
Surgical intervention within the heart by a thoracotomy generally requires isolation of the heart and coronary blood vessels from the remainder of the arterial system, and arrest of cardiac function (an “open heart” procedure). Usually, the heart is isolated from the arterial system by introducing an external aortic cross-clamp through a sternotomy and applying it to the aorta between the brachiocephalic artery and the coronary ostia. Cardioplegic fluid is then injected into the coronary arteries, either directly into the coronary ostia or through a puncture in the aortic root, so as to arrest cardiac function. In some cases, cardioplegic fluid is injected into the coronary sinus for retrograde perfusion of the myocardium. The patient is placed on cardiopulmonary bypass to maintain peripheral circulation of oxygenated blood.
Of particular interest to the present invention are open heart procedures for surgical treatment of heart valves, especially the mitral and aortic valves. According to recent estimates, more than 79,000 patients are diagnosed with aortic and mitral valve disease in U.S. hospitals each year. More than 49,000 mitral valve or aortic valve replacement procedures are performed annually in the U.S., along with a significant number of heart valve repair procedures.
Various surgical techniques may be used during an open heart procedure to repair a diseased or damaged valve, including annuloplasty (contracting the valve annulus), quadrangular resection (narrowing the valve leaflets), commissurotomy (cutting the valve commissures to separate the valve leaflets), shortening mitral or tricuspid valve chordae tendonae, reattachment of severed mitral or tricuspid valve chordae tendonae or papillary muscle tissue, and decalcification of valve and annulus tissue. Alternatively, the valve may be replaced by excising the valve leaflets of the natural valve and securing a replacement valve in the valve position, usually by suturing the replacement valve to the natural valve annulus. Various types of replacement valves are in current use, including mechanical and biological prostheses, homografts, and allografts.
The mitral valve, located between the left atrium and left ventricle of the heart, is most easily reached through the wall of the left atrium, which normally resides on the posterior side of the heart, opposite the side of the heart that is exposed by a median sternotomy. Therefore, to access the mitral valve via a sternotomy, the heart is rotated to bring the left atrium into a position accessible through the sternotomy. An opening, or atriotomy, is then made in the left atrium, anterior to the right pulmonary veins. The atriotomy is retracted by means of sutures or a retraction device, exposing the mitral valve directly posterior to the atriotomy. One of the aforementioned techniques may then be used to repair or replace the valve.
An alternative technique for mitral valve access during an open heart procedure may be used when a median sternotomy and/or rotational manipulation of the heart are/is undesirable. In this technique, a large incision is made in the right lateral side of the chest, usually in the region of the fifth intercostal space. One or more ribs may be removed from the patient, and other ribs near the incision are retracted outward to create a large opening onto the thoracic cavity. The left atrium is then exposed on the posterior side of the heart, and an atriotomy is formed in the wall of the left atrium, through which the mitral valve may be accessed for repair or replacement.
The mitral and tricuspid valves inside the human heart include an orifice (annulus), two (for the mitral) or three (for the tricuspid) leaflets and a subvalvular apparatus. The subvalvular apparatus includes multiple chordae tendineae, which connect the mobile valve leaflets to muscular structures (papillary muscles) inside the ventricles. Rupture or elongation of the chordae tendineae results in partial or generalized leaflet prolapse, which causes mitral (or tricuspid) valve regurgitation. A commonly used technique to surgically correct mitral valve regurgitation is the implantation of artificial chordae (usually 4-0 or 5-0 Gore-Tex sutures) between the prolapsing segment of the valve and the papillary muscle. This open heart operation is generally carried out through a median sternotomy and requires cardiopulmonary bypass with aortic cross-clamp and cardioplegic arrest of the heart.
Using such open heart techniques, the large opening provided by a median sternotomy or right thoracotomy enables the surgeon to see the mitral valve directly through the left atriotomy, and to position his or her hands within the thoracic cavity in close proximity to the exterior of the heart for manipulation of surgical instruments, removal of excised tissue, and/or introduction of a replacement valve through the atriotomy for attachment within the heart. However, these invasive open heart procedures produce a high degree of trauma, a significant risk of complications, an extended hospital stay, and a painful recovery period for the patient. Moreover, while heart valve surgery produces beneficial results for many patients, numerous others who might benefit from such surgery are unable or unwilling to undergo the trauma and risks of current techniques.
One alternative to open heart surgery is a robotically guided, thoracoscopically assisted cardiotomy procedure marketed under the tradename of the DaVinci® system. Instead of requiring a sternotomy, the DaVinci® system uses a minimally invasive approach guided by camera visualization and robotic techniques. Unfortunately, the DaVinci® system is not approved for mitral valve repair procedures on a beating heart. Thus, the use of the DaVinci® system for mitral valve repair still requires a cardiopulmonary bypass with aortic cross-clamp and cardioplegic arrest of the heart.
While there are other laparoscopic and minimally invasive surgical techniques and tools that have been developed, none of these devices are useable for the unique requirements of mitral valve repair on a beating heart. Suturing devices like the Superstich™ vascular suturing device or the Gore® suture passer are designed to permit manual placement of sutures as part of a surgical procedure, but are not designed for use on a beating heart. While certain annuloplasty techniques and instruments that can suture an annuloplasty ring as part of vascular repair or heart bypass surgery may be used in conjunction with a beating heart, these annuloplasty procedures do not involve the capture or retention of a constantly moving leaflet. Consequently, the design and use of annuloplasty techniques and instruments are of little help in solving the problems of developing instruments and techniques for minimally invasive thoracoscopic repair of heart valves during a beating heart procedure.
Recently, a technique has been developed for minimally invasive thoracoscopic repair of heart valves while the heart is still beating. Int\'l Pub. No. WO 2006/078694 A2 to Speziali, which is incorporated by reference herein, discloses a thoracoscopic heart valve repair method and apparatus. Instead of requiring open heart surgery on a stopped heart, the thorascopic heart valve repair methods and apparatus taught by Speziali utilize fiber optic technology in conjunction with transesophageal echocardiography (TEE) as a visualization technique during a minimally invasive surgical procedure that can be utilized on a beating heart. U.S. Publication No. 2008/0228223 to Alkhatib also discloses a similar apparatus for attaching a prosthetic tether between a leaflet of a patient\'s heart valve and another portion of the patient\'s heart to help prevent prolapse of the leaflet and/or to otherwise improve leaflet function.
More recent versions of these techniques are disclosed in U.S. Patent Application Publication Nos. 2009/0105751 and 2009/0105729 to Zentgraf, which disclose an integrated device that can enter the heart chamber, navigate to the leaflet, capture the leaflet, confirm proper capture, and deliver a suture as part of a mitral valve regurgitation (MR) repair.
These references disclose suturing valve leaflets by accessing the heart through an open surgical approach that requires an artificial opening in the heart wall be made, for example at the apex of the ventricle, during the open surgical approach. It would be advantageous for a minimally invasive suture delivery system to be able to suture valve leaflets in a beating heart procedure without requiring an open surgical approach or an incision into the exterior ventricular wall in order to minimize blood loss.
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OF THE INVENTION
Embodiments of the present invention allow for repair of heart valve regurgitation during a beating heart procedure including various steps and apparatuses for entering the heart chamber, navigating to a heart valve leaflet, capturing the leaflet, confirming proper capture, and delivering a suture. The devices and procedures of these embodiments can be used with an intravascular catheter based approach for delivery of sutures for the treatment of heart valve regurgitation.
In one embodiment, the system provides venous access into a heart chamber (venous access via the femoral or jugular vein) while minimizing the loss of blood within and without the system. The device can be inserted through the right atrium and into the right ventricle, with the position within the ventricular apex visualized via ultrasound or fluoroscopy. Once access into the heart chamber is achieved, the system is positioned via a non-invasive imaging modality. The system allows capture of intra-cardiac tissue structure. Once captured, the system allows control to be maintained over said tissue structure. Imaging modalities allow confirmation of proper capture position of the system relative to the tissue structure. The system then accommodates the delivery of the deployment catheter to said tissue structure once proper position has been confirmed.
In one embodiment, a guide-in-guide catheter system provides venous access to the ventricular septal wall for a trans-septal puncture tool to provide the access to the left ventricular cavity. Once the left ventricle is accessed, an internal guide catheter can be advanced within the external guide across the septal wall into the left ventricle. The external guide catheter can have a side exiting lumen to facilitate the positioning of the internal guide, or alternatively a septal puncture catheter with a septal puncture device therein, to the selected area for crossing the ventricular septum. A curve in the guide can angle the tip of the catheter to the desired location for trans-septal puncture. A guide wire may be used to maintain position. After the septal puncture is completed the device can be removed and a dilator inserted into the internal guide to aid the passage of the guide through the septal wall. The dilator can be removed after the internal guide has crossed the septal wall. The internal guide can also have a pre-shaped curvature to the distal tip. This curve can provide the direction support to guide the deployment catheter toward the mitral valve.
The deployment catheter can have a central lumen to accept a guide wire used in positioning the deployment catheter to effectively engage the mitral valve. The central lumen can also be used for an intravascular ultrasound device or a direct visualization device. The suture is deployed by the deployment catheter at the selected site. The deployment catheter can be withdrawn from the guide catheter and re-loaded or replaced for successive suture deployments.
In one embodiment, a medical repair device may be added to the procedure, such as a leaflet extension, a passive valve occlusion device or a pledget. The deployed sutures exit the internal guide catheter and can be temporarily fixed outside the body. Once the desired amount of sutures is positioned, they can be loaded through a central lumen of a septal seal device. The septal seal device is advanced through the external guide catheter and guided, via the sutures and external guide catheter, through the ventricular puncture site. The right ventricular side of the seal device is deployed and then the left side of the seal device is deployed. The internal catheter is then detached from the septal seal element and withdrawn from the external guide catheter. The sutures remain in the internal lumen of the septal closure device attached to the mitral valve and exit through the external guide.
In one embodiment, the sutures can have the tension individually adjusted to evaluate the physiological effect. The evaluation can be done using transesophageal echocardiography or other non-invasive methods. If the suture is overly tightened, a catheter can be delivered through the external guide to the lumen seal inside of the septal seal device. Advancing the catheter through the seal will release suture tension and allow for re-tensioning. When the tensioning task is complete, the sutures can be fixed at the septal seal element.
In one embodiment, an anchor catheter with a distally mounted cam lock element or other mechanical lock permanently fixes to the septal seal element and fixes the position of the sutures while maintaining the adjusted tension. This step completes the septal seal and suture tensioning. The anchor catheter can then be withdrawn with the proximal ends of the sutures. The sutures can then be threaded through the lumen or opening of a cutting catheter. A cutting catheter can be advanced over the sutures until it contacts the septal seal device. The cutting catheter then cuts the sutures at the seal to complete the implant procedure. The entire catheter system is then removed from the patient and the access site closed.
In another embodiment, a deployment catheter is capable of multiple suture deployments in a single activation. This would reduce the number of instrument exchanges and provide increased control of the position of the sutures relative to each other.
A further embodiment uses the sutures to deliver a biomatrix patch to enhance closure. The patch can be attached to the valve with the sutures. The patch could be delivered to either the ventricular or atrial side of the mitral valve leaflet. This patch can improve leaflet coaptation and reduce/eliminate mitral valve regurgitation by augmenting the native leaflet tissue structure supported by the delivery of a biomatrix material that can support the mitral valve annular ring or subvalvular apparatus.
Another embodiment includes the deployment of a passive occlusive device intended to improve valve closure, the device would be delivered, positioned and anchored via the ventricular septal approach described herein.
The above summary of the various embodiments of the invention is not intended to describe each illustrated embodiment or every implementation of the invention. This summary represents a simplified overview of certain aspects of the invention to facilitate a basic understanding of the invention and is not intended to identify key or critical elements of the invention or delineate the scope of the invention.
BRIEF DESCRIPTION OF DRAWINGS
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The embodiments of the present invention may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings, in which: