Patent Publication Number: US-2004059403-A1

Title: Suture sleeve

Description:
BACKGROUND OF THE INVENTION  
       [0001] This invention relates generally to suture sleeves for anchoring the lead bodies of implantable medical devices such as cardiac pacemakers, and more particularly to a suture sleeve assembly for securely gripping and anchoring a lead body without damage thereto.  
       [0002] During the implantation of an endocardial lead body, the lead is introduced into the heart using a venous approach, usually from the subclavian or cephalic vein in the shoulder area under the pectoral muscle. To stabilize the lead body at the venous entry site, the lead body is secured to both the vein and to the surrounding fascia tissue. A suture placed around the vein near the lead entry point ties the lead body to the vein, and a suture sleeve around the lead body is used to anchor the lead body to adjacent tissue.  
       [0003] Suture sleeves in present use are generally tubular structures molded out of a soft, implantable elastomer, such as silicone. After the lead body is tied to the vein, the sleeve is slid along the lead body to the location at which the lead is to be anchored to the underlying tissue. One or more sutures are then tied around the sleeve to compress it and thereby secure it to the lead body. Circumferential grooves in the outer surface of the sleeve are typically provided for this purpose. The last step is to anchor the sleeve to adjacent body tissue; sutures passed through eyelets formed in a pair of tabs projecting from the sleeve provide the required anchoring.  
       [0004] These existing suture sleeves have several drawbacks. For example, it is difficult for the physician to control the degree to which these sleeves are compressed when they are secured to the lead body. The ligature around the sleeve must be tight enough to prevent the lead body from sliding in the suture sleeve but not so tight as to damage the insulation of the lead body. This is especially important with bipolar coaxial leads because an excessively tight ligature could rupture the lead insulation and cause the outer and inner electrical leads to come into contact with each other, resulting in a short circuit. Over tightened ligatures can also result in electrical lead fractures. These problems are common enough to warrant the inclusion of cautionary information in pacemaker product literature or in notices included in the product packaging regarding the use of anchoring sleeves. It would therefore be desirable to eliminate the need for sutures for compressing the sleeve.  
       [0005] The foregoing illustrates limitations known to exist in present suture sleeves. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.  
       SUMMARY OF THE INVENTION  
       [0006] In one aspect of the present invention, this is accomplished by providing a suture sleeve comprising: a tubular body having a flexible bore extending longitudinally therethrough and having an expandable closed annular space circumferentially extending at least partially around the bore.  
       [0007] In another aspect of the present invention, this is accomplished by providing a suture sleeve comprising: a tubular body having a bore extending therethrough and an internal cavity circumferentially extending partially around the bore; and an inflatable balloon within the tubular body internal cavity.  
       [0008] In another aspect of the present invention, this is accomplished by providing a suture sleeve comprising: a reinforced silicon tubular body having: a flexible bore extending therethrough; an internal cavity circumferentially extending partially around the bore; and a plurality of attachment wings extending outward from the tubular body, the bore having a plurality of inwardly extending ridges thereon, the plurality of inwardly extending ridges comprising pairs of opposed arcuate ridges, each arcuate ridge circumferentially extending less than 180°, a pair of arcuate ridges being longitudinally spaced from an adjacent pair of arcuate ridges, a central portion of an undersurface of the tubular body being substantially flat; and an inflatable balloon within the tubular body internal cavity, the balloon having a self-sealing inflation port, the inflation port extending through an external surface of the tubular body.  
       [0009] In another aspect of the present invention, this is accomplished by providing a method of anchoring a lead body of an implantable surgical device comprising the steps of: providing a suture sleeve having a through bore and having an inflatable lead body engaging portion, the lead body extending through the suture sleeve bore; securing the suture sleeve to the desired tissue; and inflating the inflatable lead body engaging portion of the suture sleeve to engage the suture sleeve with the lead body.  
       [0010] In another aspect of the present invention, this is accomplished by providing a surgical kit comprising: an inflatable suture sleeve having a bore extending therethrough and an inflatable chamber at least partially surrounding the bore; a syringe; and a predetermined amount of saline solution for filling the suture sleeve inflatable chamber.  
       [0011] The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
     [0012]FIG. 1 is a front elevational view of a human upper torso of a patient and shows a pacer lead extending between a pacer and a heart with the lead being fixed by a suture sleeve of the present invention to the patient&#39;s skin;  
     [0013]FIG. 2 is a top view of a suture sleeve according to the present invention;  
     [0014]FIG. 3 is a side view of the suture sleeve shown in FIG. 2;  
     [0015]FIG. 4 is a cross-sectional side view of the suture sleeve taken on line  4 - 4  of FIG. 2;  
     [0016]FIG. 5 is an end view of the suture sleeve shown in FIG. 2;  
     [0017]FIG. 6 is a cross-sectional view of the suture sleeve taken on line  6 - 6  of FIG. 2;  
     [0018]FIG. 7 is a schematic cross-sectional view of a portion of the suture sleeve shown in FIG. 2 illustrating the clamping of the pacer lead;  
     [0019]FIG. 8 is an exploded perspective of an inflation nipple on the suture sleeve shown in FIG. 2 and an inflation syringe;  
     [0020]FIG. 9 is side view of an inflation syringe for use with the suture sleeve shown in FIG. 2;  
     [0021]FIG. 10 is a side view of a staple for use with the suture sleeve shown in FIG. 2;  
     [0022]FIG. 11 is a schematic view of a portion of the suture sleeve shown in FIG. 2, showing the attachment of the suture sleeve with a staple to tissue; and  
     [0023]FIG. 12 is a perspective view of a surgical stapler for use with the suture sleeve shown in FIG. 2. 
    
    
     DETAILED DESCRIPTION  
     [0024]FIG. 1 shows a pacer system  10  including a pacer  12  adapted to be inserted in a pocket on the chest  14  of a patient and a pacer lead  16  having a tip electrode assembly  18  implanted within the patient&#39;s heart  20 . The pacer lead  16  extends from the pacer  12  to a position or area  22  where the pacer lead  16  extends into and through a vein to the heart  20  where the tip electrode assembly  18  is positioned in a chamber of the heart  20  for pacing of the heart  20 .  
     [0025] Once the tip electrode assembly  18  of the pacer lead  16  is appropriately positioned, an elastomeric suture sleeve  24 , which has been positioned on the lead  16  and, which is movable thereon, is moved along the lead  16  to a location where it is desirable to fasten the lead  16  to underlying tissue  80  (See FIG. 11). In FIG. 1, the suture sleeve  24  is fastened to underlying tissue in the area  22  near where the pacer lead  16  exits the vein.  
     [0026] Suture sleeve  24  can be used with other types of implantable surgical devices in addition to pacer systems.  
     [0027] Briefly, the present invention consists of an inflatable suture sleeve  24 . The suture sleeve  24  has an internal cavity  25 , which, preferably, has an inflatable balloon  46  therein. The suture sleeve  24  is positioned as desired and is sutured or stapled to tissue  80  within the patient&#39;s chest  14 . An inflation syringe  60  is attached to an inflation nipple  36  on suture sleeve  24 . Then a predetermined quantity of saline solution  74  is injected into balloon  46  expanding the balloon so that internal ridges  40 , on a flexible bore  38  through which pacer lead  16  extends, tighten against pacer lead  16  to securely hold the pacer lead  16  to the suture sleeve  24 . Inflatable suture sleeve  24  secures pacer lead  16  as balloon  46  causes pressure and snug fit against pacer wire  16  when inflated. When not inflated, suture sleeve  24  can be re-positioned on pacer wire  16 , as do prior art suture sleeves.  
     [0028]FIGS. 2 through 7 show the suture sleeve  24  of the present invention. Suture sleeve  24  has a flexible tubular central body  26  with a flexible bore  38  extending lengthwise therethrough. Pacer lead  16  fits through the flexible bore  38 . Suture sleeve  24  has a pair of attachment wings  28  extending laterally from the tubular body  26 . Each attachment wing  28  has at least one staple/suture hole  30  to allow the suture sleeve  24  to be sutured or stapled to the surrounding tissue  80 . A raised guide ring  32  extends almost all the way around staple/suture hole  30  to guide the placement of a staple  34  as shown in FIG. 2.  
     [0029] The interior of suture sleeve  24  has an internal cavity or closed annular space  25  that extends circumferentially around flexible bore  38 . Preferably, the internal cavity extends only partially around flexible bore  38  as shown in the FIGURES. FIG. 4 shows the internal cavity exterior wall  44  and the internal cavity interior wall  42 . Preferably, an inflatable balloon  46  is positioned within this internal cavity. Balloon  46  also has an outer wall  47  proximate the internal cavity exterior wall  44  and an inner wall  48  proximate the internal cavity inner wall  42 . This arrangement provides four layers, internal cavity exterior wall  44 , internal cavity interior wall  42 , balloon inner wall  48  and balloon outer wall  47 , against leakage of the saline solution  74  used to inflate the balloon  46 . Although it is preferred to use balloon  46 , suture sleeve  24  could be used without the balloon  46 . In this event, the saline solution  74  would be injected into the internal cavity  25  to inflate the suture sleeve  24 .  
     [0030] Balloon  46  can be fixed to the interior surface of the suture sleeve internal cavity or it can be positioned within the cavity and be free to move relative to the internal cavity surfaces. Suture sleeve  24  has an inflation nipple  36  with a self sealing port  52  therein. Balloon  46  extends upward into inflation nipple  36  and is in fluid communication with self sealing port  52 . Self sealing port  52  is similar to an IV port or lock. Preferably, inflation nipple  36  extends up and away from pacer bore  38  so that insertion of needle  62  does not inadvertently penetrate balloon  46  (other than through self sealing port  52 ) or pacer lead  16 .  
     [0031] Preferably, the interior of flexible bore  38  has a plurality of inwardly projecting ridges  40  to more tightly engage the pacer lead  16 . Ridges  40  are arranged as a plurality of longitudinally spaced pairs (See FIGS. 4 through 7). Each pair consists of opposed rings that extend partially around the inner circumference of flexible bore  38 . Preferably, each ring extends less than 180° around the inner circumference so that flexible bore  38  can compress against pacer lead  16 . The wall areas  41  of flexible bore  38  are thin, compared to the thickness of ridges  40 , so that bore  38  is flexible and will compress against pacer lead  16  when balloon  46  is inflated.  
     [0032] Preferably, suture sleeve  24  is flexible so that the internal cavity can expand and contract with balloon  46 . However, suture sleeve  24  can be less flexible or semi-rigid so that balloon  46  expands and contracts independently of the internal cavity.  
     [0033] Suture sleeve  24  is preferable formed from reinforced silicon. The preferred reinforcement is a nylon net or mesh to add strength to suture sleeve  24  and to prevent tears. Additional reinforcement can be added around the suture/staple holes  30 . Suture sleeve  24  has a smooth contour to avoid adding more surface features conducive to infection. The bottom  50  (or at least a central portion of the bottom) of suture sleeve is preferably flat, to facilitate attachment to tissue  80 .  
     [0034] Reinforcement or guide ring  32  along with inflation nipple  36  can be colored to help visualize the suture or staple placement or the inflation syringe needle insertion.  
     [0035]FIG. 9 shows an inflation syringe  60  for use with suture sleeve  24 . Syringe  60  has a barrel  73  filled with a predetermined amount of saline solution  74 . Alternatively, saline solution  74  could be provided separately and then drawn into barrel  73 . A plunger  66  fits into barrel  73 , which, when pressed, expels saline solution  74  out of syringe  60 . A needle  62  is provided on the end of barrel  73 . A guide cone  64  surrounds needle  62  to protect needle  62  and to guide needle  62  into self sealing port  52  in inflation nipple  36 . Since inflation nipple  36  preferably extends upward and away from the outer surface of suture sleeve  24 , this helps prevent inadvertent insertion of needle  62  into suture sleeve  24  at locations other than inflation nipple  36 . Guide cone  64  also helps to prevent inadvertent injury from needle  62 . To facilitate handling of syringe  60 , a pair of finger supports  70  project from opposite side of barrel  66 . These supports  70  are intended for middle and index fingers. A thumb ring  68  is formed at the external end of plunger  66 . Plunger  66  includes a stop  72  projecting from plunger  66  to prevent the plunger from being pushed too far into barrel  73  and injecting more than the predetermined quantity of saline solution  74  into balloon  46 .  
     [0036] Syringe  60  can used to inflate balloon  46  prior to insertion of pacer  12  into a patient to assure that suture sleeve  24  will properly inflate and tighten against pacer lead  16 . After checking proper operation of suture sleeve  24 , plunger  66  is retracted while needle  62  is still inserted into inflation nipple  36  to withdraw saline solution  74  from balloon  46  to deflate balloon  46 .  
     [0037]FIGS. 10 and 11 show a surgical staple  34  for use with suture sleeve  24 . The central portion of staple  34  and the upper portions of ends or legs  78  are coated with silicon  76  to protect suture sleeve  24  and to help secure staple  34  to suture sleeve  24 . A typical single use surgical stapler  82  can be used to secure suture sleeve  24  to tissue  80 .  
     [0038] Normally, suture sleeve  24  is pre-attached to pacer lead  16 . Typically, pacer leads  16  have a variety of fittings and connections that would prevent suture sleeve  24  from being attached to pacer lead  16  after pacer lead  16  assembly. Preferably, suture sleeve and pacer lead is packaged as a kit containing a pacer system  10  with pacer lead  16  and attached suture sleeve  24 , inflation syringe  60  with predetermined quantity of saline solution  74 , surgical staples  34  and surgical stapler  82  along with other needed or preferred items.  
     [0039] When being installed, suture sleeve  24  can be attached to tissue  80  and then inflated or can be inflated prior to attachment to tissue  80 .