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Device Problem Malposition of Device (2616)
Patient Problem Insufficiency, Valvular (1926)
Event Date 08/01/2018
Event Type  Injury  
Manufacturer Narrative

This narrative is also being attached as a pdf document. The narrative includes references to underlining and figures which are not able to be seen in this test field, but which can be seen in the attached narrative. In the cardiovascular system, as well as in other organ systems throughout the body, native and prosthetic tissue erosion potentially leading to perforation is a known risk associated with the direct contact of tissue with foreign materials, such as suture or metal, or even with contact with other pathologic tissue structures, such as valve vegetations, which can occur as pathologic growths from infective endocarditis (e. G. , bhattacharyya s, hickman m, lythal d. Mitral valve "kissing" vegetation. Heart 2005;91:e43). Such inadvertent contact with foreign and pathologic structures leading to erosion, then perforation and leakage of native and prosthetic heart valve leaflets has been recognized and reported for many decades. In mdr report #2015691-2014-00314 and medwatch report (b)(4), all of then known cardiac leaflet perforations associated with the cor-knot® titanium fasteners were promptly reported. In this medwatch submission, we report one additional event of aortic valve leaflet perforation recently described to us from a heart surgeon and four additional related reports discovered from surveillance of the surgical literature. Newest report from heart surgeon: the surgeon who performed the successful re-do operation provided his perspective. He noted the bioprosthesis was not in the appropriate supra-annular location. The titanium fasteners were oriented radially projecting towards the closed leaflets, which in a beating heart during systole would open up and move outward toward the suture tails and titanium fasteners. The perforations and erosion were likely caused by repetitive contact between the moving leaflet and the cut suture tails or subsequently the more distal titanium fasteners. While he noted that the titanium fasteners appeared to hold the suture as intended, he mentioned that the prosthetic valve intra-annular location, pledget supra-location and the suture tail and titanium placement radial orientation with insufficient clearance were all problematic. While no devices, titanium fasteners or surgical images or specimens from either operation are available for our evaluation, based on re-operative surgeon's observations and analysis, the titanium fasteners performed well as intended to secure suture. There is no indication of any technology failure. Unfortunately for this patient, several probable inappropriate technique choices lead to the bioprosthesis leaflets directly contacting the remnant suture tails and, possibly, the metal of the titanium fasteners at four locations. Three of these direct contact points from suture tails and titanium fasteners projecting radially inward resulted in leaflet perforations causing regurgitant leaks that, along with the failed by-pass graft, required re-operation. Updated from cardiac surgery literature: since filing our initial response on 21 april 2017 to medwatch report (b)(4), which included a reference to: valvular regurgitation after implantation of prostheses secured with cor-knot automated fasteners brescia aa, bolling sf, patel hj (ann thorac surg june 2017;103(6):e491-e492) available online 26 november 2016. And an analysis based what was known to us at that time, extensive follow-on reviews of the surgical literature have now yielded three additional published reports associating the use of titanium fasteners with cardiac valve leaflet perforation. The earliest publication subsequently found is by balan, et. Al. , in the interactive cardiovascular and thoracic surgery and received no editorial commentaries. Two reports recently identified, also in ensuing annals of thoracic surgery publications, were published as "to the editor" reports (below: biefer and baciewicz) along with two "reply to the editor" commentaries by the authors brescia, bolling and patel who provided the above initial annals of thoracic report first electronically published in late 2016. Additional reports: balan r, mogilansky c, larsen al, massoudy p. Severe aortic regurgitation after implantation of a sutureless valve prosthesis using an automatic knot fastener device. Interact cardiovasc thorac surg. July 2017;25:153-154. Available online 31 march 2017. Biefer hrc, weber a, maisano f, benussi s. Leaflet perforation by cor-knot automated fasteners: more usual than you think. Ann thorac surg. February 2018;105:664-665. Available online 20 january 2018. Reply: brescia aa, bolling sf, patel hj, reply to the editor. Ann thorac surg. February 2018;105(2):665. Available online 20 january 2018. "reply to the editor" commentaries: baciewicz fa. Cor-knot perforation of aortic valve leaflet. Ann thorac surg. September 2018;106:936-937. Available online 12 may 2018. Reply: brescia aa, bolling sf, patel hj, reply to the editor. Ann thorac surg. September 2018;106(3):937. 12 may 2018. Note: for clarity and ease of reference, below please find citations directly quoted from the surgical literature or with paraphrased edits in {brackets} or with added underlines referenced in medwatch report (b)(4) and in the present medwatch submission: valvular regurgitation after implantation of prostheses secured with cor-knot automated fasteners brescia aa, bolling sf, patel hj {ann thorac surg june 2017;103(6):e491-e492. Available online 26 november 2016}. "valvular regurgitation is a recognized complication of aortic and mitral valve procedures. The primary mechanism of recurrent aortic insufficiency after aortic valve replacement is paravalvular leak, whereas transvalvular leak occurs less commonly. Recurrent mitral regurgitation (mr) is an important indication for a redo mitral valve operation" "the cor-knot (lsi solutions, victor, ny) automated fastener has been increasingly used for aortic and mitral valve operations. This device has been shown to be a safe, viable alternative to knot-pusher instruments and manual knot tying, with one series of minimally invasive mitral repairs showing significant time saved in cardioplegic arrest and cardiopulmonary bypass with its use". "in the 2 patients described in this case report, the leaflet defects appeared to be directly caused by continuous trauma from leaflet motion against suboptimally placed cor-knot fasteners. ". "the first patient described in this report" {re-do avr / mitral & tricuspid repair} "particularly suggests that this complication can arise from intraannular orientation of an aortic valve and use of the cor-knot device, particularly if the placed fastener is oriented toward the centerline of flow" {figs. 1 and 2}. "we have used this device liberally at our institution, but choose to place aortic valves in a supraannular position and have not seen this complication. " "the second patient described here {re-do mitral repair, tricuspid annuloplasty dehiscence repair, asd closure} demonstrates that even mitral valve repair with the cor-knot can result in leaflet damage from the fasteners, particularly if care is not taken to orient the fasteners toward the outer edge of the annuloplasty ring and not obliquely towards the posterior leaflet. " {no images of mitral valve provided}. Leaflet perforation by cor-knot automated fasteners: more usual than you think,to the editor: biefer hrc, weber a, maisano f, benussi s {ann thorac surg. February 2018;105:664-665. Available online 20 january 2018}. At our institution, the use of the cor-knot is standard in minimally invasive mitral valve reconstruction. Or more than 2 years now, in over 120 patients. Although it is uncommon, we have also observed at least 2 patients in whom a perforation of the anterior leaflet by cor-knots led to moderate to severe mitral valve insufficiency. Since the occurrence of these adverse events, we have changed our practice regarding the use of cor-knots. First, we ensure a proper atrial orientation of the cor-knots, and thus away from the leaflets, during deployment. Second, the use of cor-knots is exclusively for rigid mitral rings. After applying these changes, we have not seen any more adverse events. Reply to the editor: brescia aa, bolling sf, patel hj. {ann thorac surg. February 2018;105(2):665. Available online 20 january 2018}. We regularly use flexible, semirigid, and rigid incomplete and complete rings during our mitral operations, and we do not believe that the choice of ring should affect the propensity for cor-knot fasteners to result in perforation. We have not observed a single case of this rare adverse event of leaflet perforation over hundreds of minimally invasive and redo mitral and tricuspid annuloplasty operations. We believe that a wide variety of rings can be used with the cor-knot device and that the key to avoiding this adverse event remains devoting special consideration to needle angles and angulating the fasteners optimally. This rare adverse event is not a surgical device difficulty but rather a surgical technique problem cor-knot perforation of aortic valve leaflet, to the editor: baciewicz fa. {ann thorac surg. September 2018;106:936-937. Available online 12 may 2018}. "i have used cor-knot on both aortic and mitral valve replacements performed via a median sternotomy technique for the last 4 years. " with one "patient who developed moderate aortic insufficiency" requiring a "re-do procedure. The leaflet perforation was felt to be secondary to a medially directed cor-knot. Since this single experience with the aortic valve, i have been careful to have the cor-knot deployment device oriented with the fastener away from the prosthesis. I have not seen another occurrence since being meticulous with cor-knot device orientation. This letter is to alert the readership to the need for meticulous technique in using this device, particularly in a narrow aortic root with small prosthesis size. " reply to the editor: brescia aa, bolling sf, patel hj. {ann thorac surg. September 2018;106(3):937. Available online 12 may 2018}. We agree with dr baciewicz that surgical technique remains paramount to successful use of cor-knot fasteners, regardless of the type of utilized valve prosthesis or annuloplasty ring. As suggested in our initial article [2] and in our reply to our colleagues from zurich [4], special attention to needle angles, optimal angulation of cor-knot fasteners away from the centerline of [?]ow, and supraannular rather than intraannular positioning of the aortic prosthesis remain important in avoiding aortic valve leaflet perforation. We continue to use the cor-knot device in most of our valve procedures and, as with dr baciewicz, believe that this complication remains exceedingly rare but requires thoughtful consideration of surgical technique. Severe aortic regurgitation after implantation of a sutureless valve prosthesis using an automatic knot fastener device: balan r, mogilansky c, larsen al, massoudy p. {interact cardiovasc thorac surg. July 2017;25:153-154. Available online 31 march 2017}. We report the case of severe aortic regurgitation 8 months after implantation of a 25-mm sutureless pericardial aortic valve prosthesis. On examination of the explanted valve prosthesis, a perforation was observed in one of the leaflets. The leaflet perforation was in alignment with one of the knots produced by the automatic knot fastener. Obviously, the leaflet had hit the knot repeatedly which had caused the perforation. Leaflet perforation has been reported in the context of suture tails after manual tying. Thus, the orientation of the {titanium} knot must certainly not be towards a neighbouring leaflet. Medwatch summary and analysis: we believe the unfortunate cardiac valve perforations associated with the use of cor-knot titanium fasteners are all resultant of the iatrogenic malpositioning of the titanium fasteners relative to the moving leaflets thereby unnecessarily subjecting the adjacent leaflets to the known risk of erosion and perforation from repeated contact with a foreign material, such as the trimmed suture tails or metal titanium fastener. In reference to the related published reports, as highlighted above, outside independent experts appear to concur that this "exceedingly rare" event is associated with malpositioning of sutures, prosthetics and/or titanium fasteners. Therefore, this adverse event appears to be a technique problem, not a technology problem. Fortunately, for the patient identified in this medwatch submission, this patient benefitted from an excellent second operation and now has not only a well-functioning new aortic valve prosthesis but also a patent new by-pass graft. The placement and orientation of a titanium fastener is primarily dependent upon the placement of the suture onto which it is crimped. The suture is placed both through the adjacent tissue and, for securing a prosthetic valve, through the prosthetic valve sewing-cuff. For the type of supra-annular trifecta bioprosthetic aortic valve replacement installed in the first surgical procedure, properly placed sutures, typically with pledgets in the subvalvular position within the left ventricle, pull the aortic annulus up under the prosthetic sewing cuff positioned above the annulus. When performed properly, the suture and titanium fastener are thus oriented essentially parallel to the proximal wall of the ascending aorta and perpendicularly to the prosthetic valve's sewing-cuff. In the case of the present subject patient, the originally placed prosthetic valve was incorrectly installed in the left ventricular outflow tract within the intra-annular position (i. E. , below the supra-annular position and above the proximal sub-annular position) with the valve securing suture misplaced to be orientated perpendicular to aortic walls exiting the prosthetic valve's sewing-cuff at significant risk of having remnant suture tails directly contact the opened leaflets during systole. This improper technique, with either manually tied suture knots alone or with suture secured by a mechanical fastener, can subject the patient to an increased probability of the foreign material rubbing against the opened cusp and eventually abrade away leaflet material. Also please note, after placing each knot, the surgeon should always and can easily visually check to ensure the proper orientation of the crimped titanium fasteners along with their trimmed suture tails. As in the previously mentioned medwatch report (b)(4), this visual inspection is described clearly in step 12 of our cor-knot® instructions for use ("12. Remove device and inspect to ensure cor-knot® fastener and suture tails are oriented away from delicate tissue and prosthetic structures. ") surgeons know of the potential risk of malpositioning sutures and knots through their training, experience and the related surgical literature. Table i below illustrates the total number of cardiac surgery cases using titanium fasteners to date. With 9 reported events, the percent rate of perforations reported per cardiac surgery case is 0. 0029%. By comparison, the surgical literature reports that the paravalvular leak rate is at least approximately 2 to 4% without the use of cor-knot® for aortic valve replacements. Compared to much more common paravalvular leak rate, the rate of these associated transvalvular leak from perforations is two to three orders of magnitude lower. Table i: worldwide total number of cor-knot® titanium fasteners cases in cardiac surgery >315,000 reported leaflet perforations cases 9 rate of perforations reported / cardiac surgery case 0. 0029% relative to an ~ 2% pvl rate 2% ÷ 0. 0029% = 700x less. Assessment and plan: nine unfortunate patients required reoperation to replace leaking cardiac valves that were damaged by malpositioning of titanium fasteners and their suture tails during cardiac valve surgery. The first two patients reported by surgeons became known to us via the medwatch system, while the present subject patient in this current submission became known to us directly from the re-operating surgeon. Six other patients became known to us through the surgical literature and subsequently were also included in the medwatch responses through our submission of additional information. The association with titanium fasteners described herein has been repeatedly reported and well addressed on line and in print in the annals of thoracic surgery, one of the highest impact (impact factor = 3. 779) journals in cardiac surgery. Our company will continue to provide medwatch reports on specific new patients, if any, become known to us and will continue to include literature updates in any new related medwatch submissions unless otherwise advised by the fda. We plan to continue to aggressively educate our representatives who work with surgeons and operating room teams to further increase awareness of this very rare but significant avoidable risk.

Event Description

Approximately four years after undergoing aortic valve replacement and by-pass grafting of a branch of the circumflex artery through full sternotomy by a different surgeon at a different hospital, the (b)(6) patient presented with significant prosthetic aortic valve insufficiency (i. E. , leakage) along with a complete occlusion of his by-pass graft. At re-operation again through a sternotomy, the second surgeon reported finding the trifecta (which is a tri-leaflet bioprosthetic aortic valve designed for placement above the aortic annulus in the "supra-annular" position) to be to be surgically installed in the intra-annular position. Suture pledgets were found in the supra-annular position instead of the sub-annular position. Sutures exited the sewing cuff in the intra-annular position perpendicular to and directed toward the prosthetic leaflets. Three leaflet perforations were seen along with one leaflet erosion. The perforations were noted to be adjacent to and slightly above the leaflet nadir region of the prosthetic. It could not be determined if the leaflet perforations were from contact with the trimmed suture tails or if the leaflet reached beyond the suture tails during systole to touch the titanium fasteners used to secure the sutures holding this prosthesis. All titanium fasteners were reportedly holding in place and appeared well formed without any indication that these fasteners had moved after initially being placed. There were otherwise no unexpected findings. The operating room's camera system was not working during this operation and no video or photos were taken. In addition to the successful "re-do" aortic valve replacement, during the same second operation, a patent re-grafting of the failed by-pass was also achieved. The patient was discharged to home on post-operative day 5 with excellent functionality of both the new aortic prosthesis and by-pass revascularization and has had a smooth and uneventful recovery.

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Brand NameCOR-KNOT
Manufacturer (Section D)
7796 victor-mendon road
victor NY 14564
Manufacturer (Section G)
7796 victor-mendon road
victor NY 14564
Manufacturer Contact
christopher miller
7796 victor-mendon road
victor, NY 14564
MDR Report Key7848093
MDR Text Key119327358
Report Number1320468-2018-00004
Device Sequence Number1
Product Code HCF
Combination Product (Y/N)N
Reporter Country CodeUS
PMA/PMN NumberK100593
Number of Events Reported1
Summary Report (Y/N)N
Report Source Manufacturer
Reporter Occupation
Type of Report Initial
Report Date 08/09/2018
1 Device Was Involved in the Event
1 Patient Was Involved in the Event
Date FDA Received09/05/2018
Is This An Adverse Event Report? Yes
Is This A Product Problem Report? No
Was Device Available For Evaluation? No
Is The Reporter A Health Professional? Yes
Was the Report Sent to FDA?
Event Location No Information
Date Manufacturer Received08/09/2018
Was Device Evaluated By Manufacturer? Device Not Returned To Manufacturer
Is The Device Single Use? Yes
Is this a Reprocessed and Reused Single-Use Device? No
Type of Device Usage Initial

Date Received: 09/05/2018 Patient Sequence Number: 1