Breaking the Broken Dogma in Aortic Valve Replacement: The Nine Suture With Interstitch Pledget AVR Technique

The dogma traditionally proposed to avoid paravalvular leak is that each pair of sutures should be very close to the neighboring suture, with a maximum distance of 1 mm. This dogma was challenged with the use of only nine pairs of sutures without pledget placed equidistant along the aortic annulus, arguing that the force distribution of the sewing cuff would be sufficient to prevent leakage.

The use of pledget is controversial, as the services that advocate its placement argue for greater safety and less risk of leakage. On the other hand, those who do not use it argue that there is less interference in the LV outflow tract, theoretically reducing the LV/Aorta gradient.

In this video, the authors show a technical variation in which they use the pledgets between the pairs of sutures, which allows placement of sutures 7 mm apart. These intervals are respected equally in the suture ring of the prosthesis, avoiding pleating of the aortic annulus. Thus, surgeons can maintain the theory of the five nuts that attach the wheel to the car axle, with the security of a better apposition of the aortic and the prosthesis ring, avoiding leakage that would theoretically occur in these regions.

The Surgery

Through an upper mini sternotomy, cardiopulmonary bypass was installed with direct aortic cannulation and the right atrium. After infusion of del Nido 50 percent cardioplegia, an aortotomy in standard fashion was performed. After resection of the cusps and debridement of the calcium in the annulus, the first three stitches were placed in the three commissures and the prosthesis was measured with the specific sizer.

Next, surgeons sutured two more stitches between the commissures and the interposition of the pledget between the paired stitches. Extra care should be taken not to twist or invert the pledget, allowing a regular face-to-face apposition of the aortic and prosthetic rings. Stitches were then passed through the suture ring respecting the same distance and the prosthesis was finally lowered and tied in the aortic annulus.

Next, surgeons reviewed the LV outflow tract and the positioning of the pledgets and performed aortography with a double 4-0 Prolene running suture. An echocardiogram performed after the procedure showed no more than trivial paravalvular leak and transprosthetic gradients of less than two digits.

Tips and Pitfalls

For treatment of aortic valve diseases, the surgeon must be aware of choosing the appropriate size of the prosthesis and suturing technique. For optimal performance of the chosen prosthesis, it is necessary to have the lowest transprosthetic gradient combined with absence of paravalvular leak.

Using nine instead of the traditional fifteen or more pairs of sutures helps to reduce the number of pledgets, facilitating the wide opening of the LV outflow tract.

As shown in the video, the first stitches are placed in the three commissures, this region where the cusps meet, and form a dense histological substrate to support the sutures and fix the prosthesis without the need for pledget reinforcement. The authors emphasize the importance of keeping the suture very stretched, making it easier to see the ring and ensuring that the pledget will not twist or invert.

In valves with a predominance of insufficiency, where the rings are usually larger, surgeons can use the same number of sutures, keeping the distance gap the size of the pledget (7mm) and increasing the distance between the arms of the suture. The dense fibrous tissue of the commissures allows for greater spacing between the suture as long as the same distance is respected in the prosthetic ring avoiding annulus pleating. In case of need for extra stitches, the authors maintain the principle of placing the pledgets between the sutures if possible.

With the routine use of this pledget technique between the sutures, the sets of three points with two pledgets can be pre-assembled, which facilitates the work of the team and speeds the implantation of the prosthesis.

The authors also suggest that the industry could customize these sets of 9–12 sutures and the lengths of the pledgets, increasing the possibilities of use for different ring sizes.

References

1. Spindel, S. (n.d.). Breaking Dogma in Aortic Valve Replacement: The Nine Suture AVR Technique. https://doi.org/10.25373/CTSNET.25343044
2. Beddermann, C., & Borst, H. G. (1978). COMPARISON OF TWO SUTURE TECHNIQUES AND MATERIALS: RELATIONSHIP TO PERIVALVULAR LEAKS AFTER CARDIAC VALVE REPLACEMENT. Cardiovascular Diseases, Bulletin of the Texas Heart Institute, 354.
3. Borger, M. A., Nette, A. F., Maganti, M., & Feindel, C. M. (2007). Carpentier-Edwards Perimount Magna Valve Versus Medtronic Hancock II: A Matched Hemodynamic Comparison. Annals of Thoracic Surgery, 83(6), 2054–2058. https://doi.org/10.1016/J.ATHORACSUR.2007.02.062
4. Sievers, H. H. (2005). Prosthetic aortic valve replacement. Journal of Thoracic and Cardiovascular Surgery, 129(5), 961–965. https://doi.org/10.1016/J.JTCVS.2004.12.036
5. Thorac Surg Vinod Thourani, A. H., Murat Tuzcu, E., Webb, J., Williams Michael Reardon, M. R., Brett Reece, T., Russell Reiss, G., Roselli, E. E., Smith, C. R., Kapadia, S., Leon, M. B., Lima, B., Lytle, B. W., Mack, M. J., D, R. S., Gleason, T. G., Harrington, K. B., Joseph Bavaria, S. E., Blackstone, E. H., David, T. E., … Williams, M. R. (2013). Measures Aortic Valve and Ascending Aorta Guidelines for Management and Quality Aortic Valve and Ascending Aorta Guidelines for Management and Quality Measures. ATS, 95, S1–S66. https://doi.org/10.1016/j.athoracsur.2013.01.083

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