Abstract:
A heart valve sizing ring is disclosed. The sizing ring includes an outer ring; and an inner ring configured and arranged to couple to the outer ring. The outer ring and inner ring having a pair of complementary mating surfaces configured and arranged to grip sutures therebetween when coupled together. When coupled around sutures, the assembled ring may be tightened down against the heart valve to test the fit as if the sizing ring were a similarly sized prosthetic heart valve ring. The surgeon can then remove the sizing ring and replace it with a prosthetic ring.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent document claim priority to earlier filed U.S. Provisional Application Ser. No. 61/551,728, filed on Oct. 26, 2011, and U.S. Provisional Application Ser. No. 61/555,002, filed on Nov. 3, 2011, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present patent document relates generally to heart valve repair in open heart surgery and more specifically to a heart valve sizing ring and method to properly size a heart valve reinforcement ring prosthesis for proper implantation. 
         [0004]    2. Background of the Related Art 
         [0005]    Accurate selection of ring size and shape is a critical component of heart valve repair surgery. Current “annulus-sizers” or “valve-sizers” are, by design, not very accurate at actually assessing size (they only provide an estimate) and, certainly, provide no ability for physiologic assessment of the repair procedure in terms of valve function after repair. 
         [0006]    Therefore, there is a perceived need in the industry for a ring sizing tool that allows the surgeon to accurately assess the size of the ring prosthesis needed and allows assessment of the fit on the patient, i.e. whether the fit is leaky or too tight. 
       SUMMARY 
       [0007]    The present invention solves the problems of the prior art by providing a ring sizing tool that includes an outer ring portion with small gap formed therethrough and an inner mating surface on the interior portion of the ring. An inner ring is sized to snap fit into the outer ring and includes a reciprocal mating surface designed to engage the inner mating surface of the outer ring yet prevent damage to sutures. The reciprocal surface preferably includes an outwardly deflected portion to direct sutures away from the heart valve. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings where: 
           [0009]      FIG. 1  is a perspective view of an embodiment of a heart valve ring sizing tool of the present invention; 
           [0010]      FIG. 2  is an exploded view of an embodiment of a heart valve ring sizing tool of the present invention; 
           [0011]      FIG. 3  is a cross-section view through line  3 - 3  of  FIG. 2 ; 
           [0012]      FIG. 4  is a perspective view of the sutures being gathered within the outer ring an embodiment of a heart valve ring sizing tool of the present invention; 
           [0013]      FIG. 5  is a perspective view showing of an embodiment of a heart valve ring sizing tool of the present invention in place over a heart valve with the sutures trapped between the outer and inner rings; 
           [0014]      FIG. 6  is a cross-section view through line  6 - 6  of  FIG. 5 ; 
           [0015]      FIG. 7  is a perspective view of an alternative embodiment of the heart valve ring sizing tool of the present invention with the rings separated; 
           [0016]      FIG. 8  is a perspective view of an alternative embodiment of the heart valve ring sizing tool of the present invention with the rings locked together; 
           [0017]      FIG. 9  is a perspective view of a second alternative embodiment of the heart valve ring sizing tool of the present invention with the rings separated; 
           [0018]      FIG. 10  is a perspective view of a second alternative embodiment of the heart valve ring sizing tool of the present invention with the rings locked together; 
           [0019]      FIG. 11  is a perspective view of a third alternative embodiment of the heart valve ring sizing tool of the present invention that use a handle with a flexible shaft attached to the outer ring with a removable inner ring; 
           [0020]      FIG. 12  is a perspective view of a fourth alternative embodiment of the heart valve ring sizing tool of the present invention that uses a handle for each of the inner ring and the outer ring; and 
           [0021]      FIG. 13  is a perspective view of a fifth alternative embodiment of the heart valve ring sizing tool of the present invention that includes a unitary inner and outer ring attached to a single handle. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]    The present invention is described generally for mitral heart valve repair surgery. But it is to be understood that the present invention may be adapted for use on tricuspid valve repair and aortic root/annulus remodeling procedures (such as Tirone David type-operations) where the present invention may be used to simulate down-sizing the aortic root as would be created by tube graft material. 
         [0023]    The proposed device will: 1) provide a quick, more realistic, useful, functional, true-measurement of mitral annulus size, and 2) allow for critical physiologic assessment of valve function (and consequently the repair quality) prior to final and permanent ring selection and allow for such physiologic measurement and assessment using several different ring sizes and/or different ring models and shapes. 
         [0024]    The key to proper/improved ring selection is not “just guessing” after estimation of size and shape based on examination/measurement of visualized anatomy but on the potential information gained from assessment of actual physiologic consequences secondary to ring implantation. The proposed device will allow for a quick assessment of the valve annulus/repair with the ability to then again quickly assess the same repair with a different sized or shaped device representing a corresponding different sized/shaped ring prior to final selection. 
         [0025]    A key feature of this device is that an evaluation of valve physiology (i.e. testing a particular size and shape ring on the valve) can be obtained prior to commitment to a particular ring, which, under normal circumstances, is then (permanently) sewn into position. Currently, it is only after the ring is sewn into position, that the valve&#39;s repair status can be optimally assessed intraoperatively. 
         [0026]    The principal design would feature a device which quickly “captures” and aligns the ring sutures after they have been placed in the mitral valve annulus and after any complex repair had been completed such as quadrangular resection, etc. The alignment/positioning of the ring sutures would be such that the annulus size and shape, corresponding to a particular ring, would be essentially reproduced for the purpose of a quick, accurate assessment of function of the new post-repair physiology, degree of leaflet coaptation, etc. The device could be quickly exchanged for another similar device which represents the different size and/or shape of another ring. If several such measurements can be executed efficiently and safely, the surgeon will be much more informed and secure in his decision regarding ring selection as it will be based, at least to a significant degree, on actual measurement and more importantly on actual physiologic assessment. 
         [0027]    It is the hope that such preliminary physiologic assessment will translate into the best final outcome for the patient. The added information provided by quick and more accurate assessment of valve function, as described above, has the potential to significantly diminish the dreaded consequence of having to entirely remove and replace a poorly functioning valve ring/repair after separation from bypass and realization that the valve repair is functioning sub-optimally (or that a sub-optimal repair is left in place and “accepted” even though the surgeon is clearly unhappy with the suboptimal result). “Undersizing” of the annulus can also be better avoided and thus reduce the incidence of the unfavorable complication of “SAM” (systolic anterior motion) or having suboptimal hemodynamics from a smaller valve orifice or ring prosthesis shape. 
         [0028]    The described functions of this device can be achieved in a variety of ways. Referring now to  FIGS. 1-2 , a first embodiment  10  of the heart valve sizing tool of the present invention includes two rings  12 ,  14  which “snap” together. The outer ring  12  could be incomplete, having a small gap  15 , to allow it to be used to gather all of the annular sutures within the outer ring  12  in a quick and easy manner (as shown in  FIG. 4 ). The inner ring  14  would be complete and would “snap” into the slightly larger outer ring  14 . In doing so, the two rings  12 ,  14  would firmly, yet without damage to suture material, capture all sutures  16  in between the two rings  12 ,  14  (best seen in  FIGS. 5 and 6 ). The device could then be “seated” into position (at annular level) in a fashion that mimics the function of a particular ring. 
         [0029]    The inner ring  14  preferably includes a concave surface  18  on the outer portion of the ring  14 . The outer ring  12  preferably includes a complimentary convex surface  20  on the inner portion of the ring  12 . The concave and convex surfaces  18 ,  20  couple together to hold the rings  12 ,  14  in an assembled state as shown in  FIG. 3 . Because the inner ring  14  includes a concave surface  18  and the outer ring  12  includes a convex surface  20 , the sutures  16 , when captured between the rings  12 , 14 , are deflected outwards and away from the heart valve  22  permitting assessment of the physiology by being able to better view the fit. 
         [0030]    The inner ring  14  and outer ring  12  may each optionally include a tab  24 ,  26 , respectively, extending from a portion of the ring  12 ,  14 , preferably the bottom portion, to enable forceps to position and pull apart the two rings  12 ,  14 . The tabs  24 ,  26  may be angled away from the center of the rings  12 ,  14  for easier gripping and manipulation. 
         [0031]    Each particular device would correspond to a particular ring product of specified size and shape reproducing anticipated valve physiology should that particular ring size/shape be selected. The valve repair could be “tested” in standard fashion by “pressurizing” with saline, by examination, and/or by other techniques. When ring function is reproduced in this manner, leaflet coaptation, as well as success of repair techniques, can be evaluated and compared at various ring sizes/shapes prior to final selection of the optimal, simply by swapping out the sizing device for one of different size/shape. Several different ring sizes(/shapes) could be quickly swapped in and out for evaluation allowing for an informed, objective decision to be made. The device could be made of a variety of materials. Standard considerations would of course apply such as cost, bioreactivity, etc. 
         [0032]    Ideally the device would be composed of a material which would not harm/damage/weaken/fray sutures. One such example of the device would be two hard (metal, plastic, etc.) rings with a soft rubber-like outer layer on each. The metal, or other similar firm material, would provide support and accuracy in size and shape, while the outer rubber, or similar material with resilient properties, layer would not only protect, but also, delicately, yet firmly, “grasp” the sutures between the two rings. Ideally, the “grip” on the sutures would be such that device would not slip over the sutures passively but could actively be slid by the surgeon across the sutures to allow for seating into the desired position up against the valve annulus. 
         [0033]    In one embodiment of the heart valve sizing tool would be “stiff” to approximate the function of a “stiff” ring (possibly metal, plastic, etc). Though, other versions may exist to best approximate the physiologic support provided by various other types of rings (soft, partial, etc.). Ideally each size and variety/shape of mitral ring might have its own version of a sizing device. Optionally, to facilitate ring separation, small tabs (or similar structures) could be attached to each ring. The device may also be constructed in one of several other forms all of which achieve the previously stated general goals, but possibly with certain advantages or features. 
         [0034]    Another embodiment of the device could be a solid “double-ring” design as one single (connected) unit. The inner ring would be solid 360 degrees, while the outer ring would be near 360 degrees (with a small access slit for example). This would allow the surgeon to gather all sutures with a single 360 degree “twirl” motion of the device. Once all sutures had been captured, the device could be pushed up against the mitral annulus (with some tension on the sutures). Variations on this particular design may include some form of mechanism which actively secures the sutures between the two rings by opposing one ring closely to the other after the sutures had been gathered. Examples could include, but are not limited to: one ring sliding (down the handle, as shown in  FIGS. 7 and 8 ) onto the other ring, +/− locking down onto the other ring. Such functions may be operated by various mechanisms, including but not limited to, twisting mechanism which tightens one ring against the other, a sliding +/− locking mechanism which could be operated, for example, by the surgeon&#39;s thumb and two fingers (similar motion as for a syringe). 
         [0035]    In another embodiment  100 , a the heart valve sizing tool includes a handle  102  (best seen in  FIGS. 7 and 8 ), similar to those used for valves/rings and may be useful with seating the device up against the annulus as well as facilitate other motions such as gathering sutures. A handle for the device could take one of several forms. The handle could be flexible, bendable, detachable (for example  FIGS. 11 and 12  the handle may be removed from the heart valve sizing tool), etc. The handle  102  could facilitate manipulation and handling of the device. It would ideally provide optimal visualization of the valve leaflets for inspection as well as “testing” for leakage. The handle  102  could include a trigger  104  to force the inner ring  14  into position within the outer ring  12  once the sutures  16  are gathered within the outer ring  12 . Pulling the trigger  104  pushes a shaft  106 , which has the inner ring  14  attached on an end thereof. The outer ring  12  is attached to a second shaft  108  in a fixed position. Full deflection of the trigger  104  aligns the inner ring  14  within the outer ring  12 . The inner and outer ring  12 ,  14  of a particular size may be exchanged from the handle  102  to the desired size. 
         [0036]    In a second alternative embodiment  200 , a heart valve sizing tool includes a syringe-type handle  202  (best seen in  FIGS. 9 and 10 ). A syringe-type handle  202  for the device could take one of several forms. The syringe-type handle  202  would be flexible, bendable, detachable, etc. The syringe-type handle  202  could facilitate manipulation and handling of the device. It would ideally provide optimal visualization of the valve leaflets for inspection as well as “testing” for leakage. The syringe-type handle  202  includes a pair of rings  204  to support the device on the surgeon&#39;s index and ring fingers. A device is operated with via the surgeon&#39;s thumb. A thumb ring  206 , attached to a shaft  208 , forces the inner ring  14  into position within the outer ring  12  once the sutures are gathered within the outer ring  12 . Pushing the thumb ring  206  pushes the shaft  208 , which has the inner ring  14  attached on an end thereof. The outer ring  12  is attached to a second shaft  210  in a fixed position. Fully depressing the thumb ring  206  aligns the inner ring  14  within the outer ring  12 . The inner and outer ring  12 ,  14  of a particular size may be exchanged from the handle  202  to the desired size. Pulling on the thumb ring  206  separates the inner ring  14  from the outer ring  12 . 
         [0037]    Referring to  FIG. 11 , a third alternative embodiment  300  of the hearts valve sizing tool is shown generally. The tool  300  includes a handle  302  with one or more shafts  304 . The shafts  304  may be flexible or rigid. At the end of each shaft  304  is an outer ring  12 , each of different and adjacent sizes. Each outer ring  12  has a matching and separable inner ring  14  as described above for the first embodiment  10 . The inner ring  14  may be inserted and removed with forceps. The inner rings  14  may also have a handle  306  extending therefrom with a flexible or rigid shaft  308  as well, to remove the need for the use of forceps to insert and remove the inner ring  14  from the outer ring  12  as seen in  FIG. 12 . 
         [0038]    Referring now to  FIG. 13 , a fifth embodiment  400  could be in the form of a single device on a handle  402  that includes a flexible or rigid shaft  404 . Sutures  16  are gathered in a circular motion of the hand within a channel  406  formed between the inner ring  414  and the outer ring  412 . The rings  412 ,  414  are “pushed up against” the valve annulus via the handle  402  for sizing and intraoperative testing of the valve repair. The inner ring  414  and the outer ring  412  may also be hinged together to permit the inner ring  414  to be swung out the way. The handle  402  may be removable also. The hinge mechanism functions in place of snapping the two rings together, as in the other embodiments, and provides ease of gathering sutures  16  while still retaining the quality of gently gripping the sutures  16  as the other embodiments described above. 
         [0039]    In all embodiments, access for sutures through the outer ring can be in the form of a simple defect. Possibly one variant would provide for temporary exposure of a defect created by a quick “bending-apart” of the ring which would then “spring-back” into its original shape of what appears to be a complete ring (possibly facilitated by a mechanism to open the device). Alternatively, a small defect can simply remain uncovered, or a small latch can cover the defect, or the outer layer can slide over the defect. 
         [0040]    Various mechanisms can be employed to hold the device (via the sutures) firmly up against the annulus. The simplest form may be simple friction provided by a rubber-like coating as described above. Though, other mechanisms/materials may provide a similar function. 
         [0041]    It would be appreciated by those skilled in the art that various changes and modifications can be made to the illustrated embodiments without departing from the spirit of the present invention. All such modifications and changes are intended to be within the scope of the present invention.