Eur J Cardiothorac Surg 2000;18:225-227
© 2000 Elsevier Science NL
Disruption of the silver and non-silver coated sewing cuff of a new generation bileaflet valve prosthesis during aortic valve replacement: report on four cases
Ulf Herold,
Henry Van De Wal,
Jarowit Piotrowski,
Heinz Jakob
Department of Thoracic and Cardiovascular Surgery, University of Essen, Hufelandstrasse 55, 45147 Essen, Germany
Received 4 February 2000;
received in revised form 2 May 2000;
accepted 10 May 2000.
Corresponding author. Tel.: +49-201-723-3151; fax: +49-201-723-5931
e-mail: ulf.herold{at}uni-essen.de
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Abstract
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Objectives: New generation bileaflet valve prostheses with a silver-coated sewing cuff like the St Jude Medical (SJM® RegentTM) model are designed to offer a larger valvular orifice as well as a better resistance to postoperative prosthetic endocarditis, at the expense of a smaller sewing cuff. Methods and results: We report on four cases of aortic valve replacement where during the implantation procedure the fixation cuff disrupted, leading to the exchange of all four valve prostheses. This happened three times with silver- coated sewing cuffs and after withdrawal of the silver- coated cuff prostheses from the market, once with a non silver- coated sewing cuff. This was due to the arbitrary cutting of the cuff fixation suture at the ventricular side of the prosthesis, although the implantation was performed according to the recommendations of the company. This problem didn't occur previously, using other models of the same manufacturer, although the sewing cuff had been fixed in the same technique. Conclusion: Fixation of smaller sewing cuffs of mechanical valve prostheses with a critically exposed fixation suture at the ventricular side of the prosthesis represents a significant risk for disruption during the implantation process through cut off by chance. We recommend meticulous inspection of the sewing cuff for signs of disruption before seating the valve into position. During follow-up particular attention should be paid to valve dislodgement and leakage. The company was informed and advised by us to modify the fixation of the prosthetic annulus of the SJM® RegentTM valve, which has led to an alternative cuff design, called the SJM FlexTM cuff.
Key Words: Heart valve prostheses • Heart valve failure • Cuff disruption
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1. Introduction
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The new generation bileaflet valve prostheses of St Jude Medical (SJM® RegentTM) are designed with a smaller silver- coated sewing cuff. At the expense of a reduced cuff size a larger valvular orifice is achieved. The silver coating of the cuff was introduced to provide a better resistance to microbial deposition aiming at the reduction of postimplant prosthetic endocarditis [1]. This offers several advantages in the effort to obtain optimal results for our patients. However, structural and functional integrity and durability of the implant material is the prerequisite to reach this goal. We report on four cases of aortic valve replacement where during placement of the sutures through the sewing cuff, the cuff disrupted necessitating the exchange of the valvular prosthesis. This happened three times with silver- coated sewing cuff prostheses and after withdrawal of this model from the market, once with a non- silver-coated sewing cuff Regent® valve prosthesis.
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2. Case reports
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Within a period of 11 weeks three different, well trained cardiac surgeons experienced the same phenomenon during aortic valve replacement using this new valvular prosthesis. The implantation and suturing technique used at our institution is standardized and corresponds to the recommendations of the company. For supraannular positioning of the valve prosthesis, suturing is performed by single U-stitches through the trimmed valvular annulus using Ethibond® 2.0 sutures armed with teflon pledgets and a V5 needle. This suture is specially designed by the Ethicon® company for aortic valve replacement and currently used by approximately 75% of the German cardiac surgical centers (Data provided by Ethicon®, Norderstedt, Germany). The attached modified V5 needle is of half round shape and has no cutting edge.
After each U-stitch the suture is passed through the sewing cuff of the prosthesis with placement of the teflon pledgets in the subannular position. During the complete suturing procedure the valve is kept mounted on the company's valve holder, hand-held by an assistant, taking great care to avoid any mechanical stress to the prosthesis and the sewing cuff. It is important to mention that the disruption of the sewing cuff in all four cases occurred before the suturing had been completed and the valve been seated into position. No specific tearing or force had been applied by the implanting surgeon.
Fig. 1
allows the clear identification of the ruptured ends of the sewing cuff fixation suture at the ventricular side, most likely caused by accidental needle puncture. This led to a zipper-like effect with progressive detachment of the sewing cuff to one third of the prosthesis'circumference up to the security sutures, which are placed every 120 degrees, to inhibit complete disruption of the cuff. The resulting cuff instability forced us to exchange the prosthesis in all four cases.
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Fig. 1. Illustrating the ends of the ruptured cuff fixation suture (arrows) and the unfolding sewing cuff.
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By immediate realization of the disruption no single patient was jeopardized by this event. However, the exchange of the prosthesis caused a prolonged aortic crossclamp time (87, 88, 75 and 90 min) resulting in an extended operation time. The postoperative course of all four patients was uneventful. Every patient could be weaned postoperatively from the respirator between 9 and 12 h and none of them showed any neurological deficit. Repeated postoperative ultrasound controls of the valve prostheses revealed proper positioning and good function with no signs of paravalvular leakage. Hospital stay was not affected and the patients were discharged between the 9th and 13th postoperative day, respectively.
Immediate and detailed discussion with St. Jude Medical® led to the replacement of all four prostheses without charge. Furthermore the company reported that this problem hadn't been observed elsewhere up to this time. While analyzing the possible causes of the cuff disruption St. Jude Medical® informed us, that the cuff design will be revisited and modified.
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3. Discussion
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A ruptured sewing cuff represents an uncommon and very rare complication in valve replacement procedures [2]. The fact that this occurred four times within 11 weeks to three different surgeons must be considered as valve related problem, taking into account that inadequate handling of the valve can be excluded.
As demonstrated in Fig. 2
by a schematic cross section of the SJM® RegentTM heart valve the sewing cuff is attached to the carbon orifice by a metal band, allowing rotation, while the plicated cuff is secured with a continuous hand stitched suture at the ventricular side of the prosthesis.
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Fig. 2. The cross-section shows the architecture of the SJM® RegentTM cuff, illustrating that the localization of the fixation suture no. 2 at the ventricular side of the valve is placed in sensitive region of the cuff where needles are passed through.
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This circumstance makes it more likely that the fixation suture critically exposed at the ventricular side might be hit by chance during the implantation procedure by a single needle puncture. Moreover this problem is enhanced due to the reduced size of the sewing cuff.
In all four patients the problem of the ruptured cuff fixation suture was recognized before the valve has been seated into position. This gives rise to the question of whether this might also happen to an already implanted prosthesis if the injured fixation suture has not been detected, or was not detectable. If so, this could result in an unstable postoperative valve position or partial dislodgement of the prosthesis.
Compared to other valve prostheses of SJM® such as the MastersTM and HPTM series, the sewing cuff is fixed with two sutures also, but the sewing cuff which is reduced in size critically exhibits the fixation suture at the ventricular side. While the valve is mounted on the valve holder apparatus, the cuff is stretched and flattened additionally at the side of the two temporary mounting sutures, resulting in a higher risk for needle punctures. This might be due to the manufacturing process, but represents a disadvantage in mechanical stability of the sewing cuff (Fig. 3) .
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Fig. 3. Compared to the SJM® RegentTM valve in the MastersTM and HPTM series the two cuff fixation sutures at the ventricular side of the valve are located closer to the carbon orifice and thereby more protected against needle punctures.
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We recommend that during the implantation procedure and while suturing the cuff of a SJM® RegentTM valve, great care must be taken to ensure that the sewing cuff is still fixed to the valve properly before seating the valve into position. In case of any doubts or signs of an injured cuff, the valve should be exchanged at once. Patients who have already a SJM® RegentTM prosthesis should be scheduled to a close follow up to ensure proper position and function of the prosthesis.
Following subsequent discussion with St. Jude Medical® the company took our concerns seriously and initiated several changes in valve cuff design to prevent this type of event. The announced new cuff design, the SJM Flex® cuff, offers a larger cuff area for needle penetration and in contrast to the cuff design of the Regent® valve, the hand stitched cuff fixation suture is repositioned from the ventricular side to the outflow side of the prosthesis, reducing the probability of needle punctures.
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References
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- Gabriel M.M., Mayo M.S., May L.L., Simmons R.B., Ahearn D.G. Silver as an antimicrobial agent. Curr Microbiol 1996;33(1):1-5.[Medline]
- Vitale N., Serena D., Fondacone C., Agnino A., Cicala P., de Luca L. Complete intraoperative dislodgement of a SJM mechanical heart valve hemodynamic plus valve sewing cuff. J Thorac Cardiovasc Surg 1996;112(6):1669-1671.[Free Full Text]
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Abstract
1. Introduction
