COR-KNOT

Additional Manufacturer Narrative

COR-KNOT® TITANIUM FASTENERS ARE USED TO SECURE SUTURE IN GENERAL AND CARDIOVASCULAR SURGICAL APPLICATIONS. IN PRACTICE, THE USER LOADS A COR-KNOT® QUICK LOAD® UNIT COMPRISING A HOLLOW COR-KNOT® TITANIUM FASTENER AND A WIRE SNARE INTO THE DISTAL TIP OF A COR-KNOT MINI® DEVICE. THE USER THEN PULLS THE SNARE TO DRAW SUTURE ENDS THROUGH THE TITANIUM FASTENER LOADED IN THE COR-KNOT MINI® DEVICE. THE SNARE IS SET ASIDE, AND THE USER GENTLY SLIDES THE DISTAL TIP OF THE LOADED COR-KNOT MINI® DEVICE OVER THE SUTURE DOWN TO A TARGETED SITE. THE USER ORIENTS THE DEVICE APPROPRIATELY AND TENSIONS THE SUTURE AS DESIRED. THE USER THEN SQUEEZES A PURPLE LEVER ON THE COR-KNOT MINI® DEVICE TO CRIMP THE TITANIUM FASTENER ONTO THE SUTURE AND TRIM THE SUTURE TAILS. THE CRIMPED COR-KNOT® FASTENER SECURES THE SUTURE. THERE IS NO REPORT THAT THE COR-KNOT MINI® DEVICE DID NOT PERFORM ITS INTENDED FUNCTION OF SECURING SUTURE WITHIN THE CRIMPED TITANIUM FASTENERS. INSTEAD, THE REPORT WAS THAT THE CRIMPED COR-KNOT® FASTENER WOULD NOT RELEASE FROM THE COR-KNOT MINI® DEVICE EVEN AFTER THE PURPLE LEVER WAS REPORTED TO HAVE BEEN RELEASED AND THE DEVICE WAS "ROTATED TO BOTH RIGHT AND LEFT". LSI WAS ABLE TO OBTAIN AND EVALUATE THE COMPLAINT COR-KNOT MINI® DEVICE. THE HOSPITAL ALSO RETURNED 14 FASTENERS CRIMPED ONTO SUTURE. VISUAL INSPECTION BEFORE AND AFTER DECONTAMINATION DID NOT REVEAL ANY PHYSICAL DAMAGE OR DEFECTS. IT WAS POSSIBLE TO FULLY LOAD THE TITANIUM FASTENERS INTO THE DEVICE TIP USING NORMAL LOADING TECHNIQUES. SUTURE WAS READILY THREADED INTO THE DEVICE AND LOADED FASTENERS. UNCRIMPED TITANIUM FASTENERS WERE PROPERLY RETAINED. UPON SQUEEZING OF THE DEVICE PURPLE LEVER, THE TITANIUM FASTENERS WERE PROPERLY CRIMPED ONTO SUTURE, AND THE RESULTANT SUTURE HOLDING FORCES WERE WITHIN SPECIFICATION. THE DEVICE LEVER RETURNED UNAIDED TO ITS FULLY RELEASED POSITION. THE BLADE CUT SUTURE WITH EASE, AND THE MEASURED FORCE TO CUT SUTURE VALUES WERE WITHIN DESIGN REQUIREMENTS AND SPECIFICATIONS. FINALLY, CRIMPED TITANIUM FASTENERS WERE EASILY RELEASED FROM THE DEVICE TIP. MEASURED FORCE TO RELEASE FASTENER AFTER CRIMP (FRAC) VALUES WERE WITHIN THE DESIGN REQUIREMENTS AND SPECIFICATIONS. ADDITIONALLY, NO FAILURES WERE NOTED IN THE FOURTEEN CRIMPED FASTENERS THAT WERE RETURNED WITH THE COMPLAINT DEVICE. THE REPORTED COMPLAINT THAT THE CRIMPED FASTENER WOULD NOT RELEASE FROM THE DEVICE COULD NOT BE REPLICATED. NO DEFECTS PERTAINING TO LOADING AN UNCRIMPED FASTENER, NOR CREATION, SECURITY, OR RELEASE OF THE CRIMPED FASTENER WERE OBSERVED DURING FUNCTIONAL EVALUATION AND INSPECTION. ALTHOUGH THE COMPLAINT STATES THE SURGEON "ROTATED TO BOTH RIGHT AND LEFT", THE COR-KNOT MINI® INSTRUCTIONS FOR USE (IFU) STATE, "IF THE CRIMPED COR-KNOT® FASTENER DOES NOT READILY RELEASE FROM THE DISTAL TIP, ENSURE PURPLE LEVER IS RELEASED, THEN GENTLY PUSH INWARD AND ROTATE THE HANDLE 90º ABOUT THE SHAFT. IF STILL NECESSARY, ROTATE THE HANDLE BACK, THEN TURN 90º IN THE OPPOSITE DIRECTION. IF COR-KNOT FASTENER WILL STILL NOT RELEASE, CUT SUTURE." THE MOST LIKELY ROOT CAUSE OF THIS COMPLAINT IS A PROBABLE USE ERROR, SPECIFICALLY A FAILURE TO PROPERLY EMPLOY THE PUSH AND ROTATE METHOD, AS OUTLINED IN OUR IFU, TO RELEASE THE CRIMPED FASTENER FROM THE DEVICE TIP. SPECIFICALLY, AS REPORTED, THE SURGEON ROTATED THE DEVICE TO THE RIGHT AND LEFT AFTER ENSURING THE DEVICE LEVER WAS FULLY RELEASED, BUT IT WAS NOT REPORTED THAT THE SURGEON GENTLY PUSHED THE DEVICE INWARD WHILE ROTATING 90° CLOCKWISE AND COUNTERCLOCKWISE ABOUT THE SHAFT. ROTATING, WITHOUT THE GENTLE PUSH, AS REPORTED HERE, DOES NOT FOLLOW THE STEPS OUTLINED IN THE IFU AND LIKELY ACCOUNTS FOR THE REPORTED DIFFICULTY RELEASING THE CRIMPED TITANIUM FASTENER. THE REPORTED LEFT VENTRICULAR RUPTURE DOES NOT APPEAR TO HAVE ANY CONNECTION TO THE REPORTED FAILURE TO RELEASE A CRIMPED FASTENER FROM THE COR-KNOT MINI® DEVICE, NOR DOES THE SURGEON MAKE ANY SUCH ALLEGATION REGARDING THE COR-KNOT MINI® DEVICE. OVER 18.9 MILLION TITANIUM FASTENERS HAVE BEEN USED IN OVER 1,171,000 CARDIAC SURGICAL PATIENTS OVER THE PAST FIFTEEN YEARS IN OVER 70 COUNTRIES. IN THAT TIME AND NUMBER OF CASES, WE HAVE NEVER HAD ANOTHER REPORT OF A LEFT VENTRICULAR RUPTURE, AND THE LEFT VENTRICULAR RUPTURE REPORTED IN THIS CASE DOES NOT APPEAR TO HAVE ANY CAUSAL ASSOCIATION WITH THE COR-KNOT MINI® DEVICE. WE ARE GRATEFUL THAT THIS PATIENT'S OPERATION APPEARS TO HAVE BEEN SUCCESSFUL. THE EXTREMELY RARE LEFT VENTRICULAR RUPTURE EXPERIENCED IN THIS UNFORTUNATE SITUATION IS NOT ATTRIBUTABLE TO THE USE OF THE COR-KNOT MINI® DEVICE. THE REPORTED DIFFICULTY IN RELEASING THE CRIMPED TITANIUM FASTENER APPEARS TO BE THE RESULT OF THE USER NOT FOLLOWING THE STEPS OUTLINED IN THE IFU FOR WHEN A CRIMPED FASTENER DOES NOT READILY RELEASE. THIS IS NOT A PRODUCT DESIGN OR MANUFACTURING FAILURE. CLOSER ADHERENCE TO THE INSTRUCTIONS FOR USE (IFU) MAY HAVE PREVENTED THIS AVOIDABLE OUTCOME.

Description of Event or Problem

THE PATIENT IS REPORTED TO HAVE UNDERGONE A MITRAL VALVE REPLACEMENT (MVR) SURGICAL PROCEDURE VIA FULL STERNOTOMY AT THE (B)(6). THE CASE WAS FURTHER REPORTED TO BE A MITRAL ANNULAR CALCIFICATION (MAC) CASE. AS REPORTED BY OUR DISTRIBUTOR, WHILE USING THE COR-KNOT MINI® DEVICE TO SECURE THE 10TH SUTURE ON THE PROSTHETIC MITRAL VALVE, THE PURPLE LEVER OF THE COR-KNOT MINI® DEVICE GOT STUCK AND WOULD NOT RELEASE WITHOUT MANUAL ASSISTANCE. THE LEVER WAS THEN MANUALLY FREED, BUT IT WAS FURTHER REPORTED THAT THE TITANIUM FASTENER "REMAINED STUCK IN THE TIP OF THE COR-KNOT DEVICE EVEN IF SURGEON ROTATED TO BOTH RIGHT AND LEFT." IT WAS THEN REPORTED THAT AFTER MOVING THE COR-KNOT MINI® DEVICE "SIDE-TO-SIDE FOR A WHILE, THE [SUTURE] BEYOND THE FASTENER SNAPPED". THE TITANIUM FASTENER WAS REPORTED TO REMAIN IN THE TIP OF THE COR-KNOT MINI® DEVICE WITH THE SNAPPED SUTURE. HOWEVER, WHEN THE SUTURE BROKE, THE PLEDGET HELD BY THE SUTURE FELL INTO THE LEFT VENTRICLE AND WAS RETRIEVED. FURTHER INFORMATION PROVIDED BY OUR DISTRIBUTOR CLARIFIES THAT TWO ADDITIONAL PROSTHETIC VALVES WERE USED IN THE SURGERY AFTER THE INITIAL PROSTHETIC VALVE. THE FIRST PROSTHETIC VALVE WAS REMOVED SO THAT THE PLEDGET WHICH FELL INTO THE LEFT VENTRICLE COULD BE RETRIEVED. AS ALSO REPORTED, THIS FIRST PROSTHETIC VALVE WAS DAMAGED WHILE MAKING AN INCISION INTO THE SEWING CUFF TO REMOVE THE VALVE. DURING PLACEMENT OF THE SECOND PROSTHETIC VALVE, A LEFT VENTRICULAR RUPTURE WAS REPORTED TO HAVE OCCURRED. THE SECOND PROSTHETIC VALVE WAS REMOVED, AND THE SURGEON IS REPORTED TO HAVE NO IDEA OF THE CAUSE OF THE LEFT VENTRICULAR RUPTURE. THE LEFT VENTRICULAR RUPTURE WAS REPAIRED, AND THEN A THIRD PROSTHETIC VALVE WAS REPORTED AS ULTIMATELY BEING SUTURED INTO PLACE. THE PATIENT IS REPORTED BY THE JAPANESE DISTRIBUTOR AS "DOING OK" AND THE OPERATING SURGEON IS REPORTED NOT TO HAVE ANY DOUBTS ABOUT THE COR-KNOT MINI® DEVICE.