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 - INTO THE DISTAL TIP OF A COR-KNOT® DEVICE. NEXT, THE USER GENTLY SLIDES THE DISTAL TIP OF THE LOADED COR-KNOT® 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 LEVER ON THE COR-KNOT® DEVICE TO CRIMP THE TITANIUM FASTENER ONTO THE SUTURE AND TRIM THE SUTURE TAILS. THE CRIMPED COR-KNOT® FASTENER SECURES THE SUTURE. THE USER THEN CONFIRMS PROPER POSITION OF THE CRIMPED COR-KNOT® FASTENER. THERE IS NO REPORT THAT THE COR-KNOT® DEVICE DID NOT PERFORM ITS INTENDED FUNCTION OF SECURING SUTURE WITHIN THE CRIMPED TITANIUM FASTENERS. THE BRAR CASE REPORT DESCRIBED AN OBSTRUCTION OF THE RIGHT CORONARY OSTIUM. IT MAY BE INTERPRETED FROM THE CASE REPORT THAT ONE OF THE COR-KNOT® FASTENERS WAS PLACED BY THE ORIGINAL SURGEON IN SUCH A WAY THAT THERE MAY HAVE BEEN AN INCREASED RISK OF OBSTRUCTING ONE OF THE CORONARY OSTIA. WE BELIEVE IT IS UNDERSTOOD BY CARDIAC SURGEONS THAT THEY SHOULD NOT PLACE ANY OBJECTS (E.G., PROSTHETIC VALVE COMPONENTS, SUTURE TAILS, TITANIUM FASTENERS, ETC.) IN LOCATIONS THAT CAN POTENTIALLY OBSTRUCT CORONARY OSTIA, REDUCE CORONARY ARTERY FLOW, AND/OR DEPRIVE HEART TISSUE OF OXYGENATED BLOOD IN THAT DISTRIBUTION. AS NOTED IN THE COR-KNOT® INSTRUCTIONS FOR USE, "WHILE THE TITANIUM OF THE COR-KNOT® FASTENER IS PHYSIOLOGICALLY VERY INERT, ROUTINE SURGICAL PRECAUTIONS MUST BE EMPLOYED WHENEVER FOREIGN MATERIALS ARE LEFT IN A PATIENT". SIMILARLY, AS ALSO NOTED IN THE COR-KNOT® INSTRUCTIONS FOR USE, "INSPECT TO ENSURE THE COR-KNOT® FASTENER AND SUTURE TAILS ARE ORIENTED AWAY FROM DELICATE TISSUE AND PROSTHETIC STRUCTURES." ALTHOUGH IT IS NOT CLEAR WHAT SPECIFICALLY WAS OBSTRUCTING THE CORONARY OSTIUM IN THIS CASE REPORT, EVEN IF IT WERE THE COR-KNOT® FASTENER, WE BELIEVE SURGEONS SHOULD APPLY APPROPRIATE JUDGMENT IN SUCH A WAY THAT THEIR TREATMENTS AND ROUTINE PRECAUTIONARY MEASURES AVOID OR MINIMIZE THE RISK OF CORONARY OSTIA OBSTRUCTION. IT IS THE SURGICAL STANDARD OF CARE TO INTRAOPERATIVELY CONFIRM THAT NOTHING PLACED IN THE PATIENT, INCLUDING A PROSTHETIC HEART VALVE, ITS METALLIC RING, OR A TITANIUM FASTENER, IS OBSTRUCTING A CORONARY OSTIUM. IN CARDIAC SURGERY, SURGEONS TYPICALLY INSPECT CORONARY OSTIA BEFORE AND AFTER WORKING AROUND THESE OPENINGS; THIS INSPECTION IS VISUAL AND FREQUENTLY ALSO INVOLVES THE USE OF ATRAUMATIC PROBES. THE CORONARY OSTIA ARE DELICATE TISSUE STRUCTURES AND SHOULD BE RECOGNIZED AS SUCH. TO AVOID CAUSING AN OBSTRUCTION OF CRITICAL BLOOD TO THE HEART, OBJECTS, INCLUDING REMNANT SUTURE TAILS AND/OR TITANIUM FASTENERS, SHOULD NOT BE ORIENTED TOWARD THE CORONARY OSTIA. IF IN FACT THIS PATIENT'S CORONARY OSTIUM WAS OBSTRUCTED, THIS OUTCOME IS MORE ATTRIBUTABLE TO A LACK OF ROUTINE SURGICAL PRECAUTIONS THAN TO COR-KNOT® TECHNOLOGY. MORE THAN 19,300,000 COR-KNOT® TITANIUM FASTENERS HAVE BEEN USED IN CARDIAC SURGERY WORLDWIDE SINCE 2011. IN THAT TIME, THE CURRENT EVENT IS ONE OF ONLY TWO REPORTED INSTANCES IN WHICH A COR-KNOT® TITANIUM FASTENER MAY HAVE BEEN POSITIONED BY A SURGEON IN A LOCATION WHERE IT COULD BLOCK A CORONARY OSTIUM. IF THIS WAS ATTRIBUTABLE TO THE FASTENER, THE EXCEPTIONALLY LOW OCCURRENCE RATE OF 0.00001% (2 IN 19.3 MILLION) ILLUSTRATES THE RARITY OF THIS RISK. HOWEVER, THERE IS NO CLAIM THAT THE FASTENER ITSELF MALFUNCTIONED IN ANY WAY. WE ARE GLAD TO HEAR THAT THE PATIENT WAS DISCHARGED AND IS REPORTED TO REMAIN WELL WITH NO FURTHER CARDIAC PRESENTATIONS OR COMPLAINTS. THE HISTORY, LITERATURE, AND KNOWN CLINICAL SURVEILLANCE OF THE USE OF TITANIUM FASTENERS IN AORTIC VALVE SURGERY STRONGLY SUPPORT THE USE OF THIS TECHNOLOGY WHEN DEPLOYED CONSISTENT WITH THE ROUTINE STANDARD OF CARE.

Description of Event or Problem

ON 28 OCT 2025, DURING A ROUTINE POST MARKET SURVEILLANCE LITERATURE SEARCH, LSI IDENTIFIED A CASE REPORT WITH A PUBLICATION DATE OF 24 OCT 2025 IN THE JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY (JACC) ENTITLED, "RECURRENT STEMI AFTER SURGICAL AORTIC VALVE REPLACEMENT", AUTHORED BY SHANJOT BRAR, MD ET AL. FOR CONVENIENCE, THIS PAPER WILL BE REFERRED TO AS THE "BRAR CASE REPORT". THE BRAR CASE REPORT DOES NOT IDENTIFY A SPECIFIC DATE FOR THE REPORTED EVENT, HOWEVER THE MANUSCRIPT FOR THE PAPER WAS NOTED AS BEING RECEIVED ON 14 AUG 2025, AND THE ORIGINAL SURGICAL PROCEDURE WAS NOTED AS OCCURRING "4 YEARS BEFORE THE CURRENT PRESENTATION", SO WE CAN CONCLUDE THE ORIGINAL SURGICAL PROCEDURE HAD TO HAVE OCCURRED PRIOR TO 14 AUG 2021. A 63-YEAR-OLD MALE PATIENT WITH A HISTORY OF BICUSPID AORTIC VALVE WITH SEVERE AORTIC STENOSIS HAD AN AORTIC VALVE REPLACEMENT (AVR) PROCEDURE. THE SUTURES HOLDING THE PROSTHETIC REPLACEMENT VALVE IN PLACE WERE SECURED WITH COR-KNOT® TITANIUM FASTENERS. ONE YEAR AFTER VALVE IMPLANTATION, THE PATIENT PRESENTED WITH CHEST PAIN AND TRANSIENT INFERIOR ST-SEGMENT ELEVATION ON HIS ECG. AS REPORTED, DUE TO THE TRANSIENT NATURE OF THE SYMPTOMS AND THE RESOLUTION OF THE PATIENT'S ST-SEGMENTS, CORONARY ANGIOGRAPHY WAS NOT PERFORMED, AND A STRESS ECHOCARDIOGRAM SHOWED NO EVIDENCE OF MYOCARDIAL ISCHEMIA. FOUR YEARS AFTER VALVE IMPLANTATION, THE PATIENT PRESENTED TO THE EMERGENCY DEPARTMENT WITH SUDDEN-ONSET RETROSTERNAL CHEST PAIN. THE PATIENT WAS DIAGNOSED WITH ST-SEGMENT ELEVATION MYOCARDIAL INFARCTION (STEMI). THE PATIENT WAS DISCHARGED HOME A COUPLE OF DAYS LATER. THE PATIENT RE-PRESENTED TWO MONTHS LATER WITH ANOTHER INFERIOR STEMI. IMAGING SUGGESTED THAT THE POSITION OF ONE OF THE COR-KNOT® TITANIUM FASTENERS USED TO SECURE THE SUTURES HOLDING THE PROSTHETIC VALVE IN PLACE WAS POSSIBLY INTERFERING WITH CORONARY FLOW TO THE RIGHT CORONARY ARTERY (RCA) BASED ON THE PROXIMITY OF THE TITANIUM FASTENER TO THE RCA OSTIUM. A STENT WAS THEN PLACED IN THE RCA OSTIUM. THE PATIENT WAS DISCHARGED AND IS REPORTED TO REMAIN WELL WITH NO FURTHER CARDIAC PRESENTATIONS OR COMPLAINTS.