Novel Sizing of Valsalva Graft for David Operation

Abstract

Stability of the aortic annulus, symmetrical commissures, and sufficient coaptation are key factors in achieving long-term durability of aortic valve reimplantation. The authors propose a novel method of prosthesis sizing, using newly designed sizers and coaptation forceps, which simplifies the steps for reimplantation of the tricuspid aortic valve.

Introduction

The technique of aortic valve reimplantation to treat aortic root aneurysm, with or without aortic valve regurgitation, has been previously described in detail (1, 2, 3, and 4). Although reimplantation techniques differ in specific points, their aim is to achieve a perfect intraoperative result and long-term stability.  The Valsalva® (Vascutek, Inchinnan, Scotland, UK) graft aims to preserve the long-term performance of the aortic valve (5).  Perfect reimplantation of the aortic valve can be achieved by reimplantation of all three commissures into a new sino-tubular junction (3).  It is well known that the occurrence of aortic regurgitation during follow-up is dependent on leaflet morphology, satisfactory coaptation length, and height and stability of the aorto-ventricular junction (AVJ). By using a novel sizing tool, the authors propose an improved sizing of the Valsalva® graft.

Description of the Method

Dissection and preparation of the aortic root is carried out in the usual way (1, 3).  A new sizing tool is used to determine the appropriate prosthesis. It consists of two components: “Trifeet” coaptation forceps and sizing ring (SR) (Asanus Medizintechnik, Neuhausen ob Eck, Germany). The sizing ring is placed around the fully dissected aortic valve, and coaptation forceps create the desired coaptation by gently pressing all three leaflets together.

The appropriate prosthesis is sized using the following principles:

1. All three commissures must be placed on the level of the upper surface of the SR.
2. The 120° orientation of the commissures is checked by comparing the three lines on the upper surface of the SR.
3. The tightness of the remnant leaflets tissue (between the coaptation forceps and the commissures) under tension above the upper surface of the SR indicates the correct diameter of prosthesis.
4. By using different sizers (28-34 mm), the appropriate prosthesis is chosen.

For the subannular fixation of the graft, six Ethibond (Ethicon, Norderstedt, Germany) “U” stitches with pledgets are used.  Three stitches are placed horizontally at the nadirs of the cusps. The commissural stitches are placed vertically to minimize interference with leaflets.  By reducing the total number of stitches, and by exact positioning of the stitches, a perfect orientation of the reimplanted valve is possible, and the overall procedural time is reduced.

The height of the commissures and preparation of the graft is performed as proposed by the El Khoury group to achieve a perfect horizontal symmetry of the valve (3).

After the prosthesis is cut, the 3/0 Prolene annuloplasty stitch is placed at a button of the prosthesis, underneath the subannular stitches. This allows further adjustment of the aorto-ventricular junction at the end of the cardiopulmonary bypass under transesophageal echocardiographic (TOE) guidance.

The six subannular stitches are passed through the graft (over the annuloplasty stitch) and the prosthesis is lowered down to the aortic annulus. Fixation of all three commissures in the neo-sinotubular junction is performed. Maintaining perfect symmetry without any distortions or loss of coaptation, all cusps are gripped with the coaptation forceps again and three stay sutures are placed in the middle at the deepest point of the reimplantation line, between remnant aortic tissue and the prosthesis. This “preloading” fixation at the nadir level allows for additional correction of a possible small prolapse.

The valve is reimplanted within prosthesis in the usual way with three 4/0 Prolene running sutures. For the reimplantation of both coronary arteries, the dynamic test using an angioscope is performed. The aortic root is pressurized with cold saline, and symmetry and appearance of the valve is visualized (6). Any additional defect in coaptation can then be managed before the aortic cross-clamp is released. The rest of the David procedure (reimplantation of both coronaries and trimming the length of the prosthesis) is carried out in the usual way.  Immediately after weaning from bypass, a final control TOE is performed. The annuloplasty stitch is carefully tied under TOE-guidance to achieve a further stabilization of the AVJ.

Conclusion

The authors present a simple method to improve the sizing of the Valsalva® graft during a standard David procedure.  Moreover, this technique minimizes the need of additional plication stitches. It offers the advantages of enabling adjustment of the final AVJ size under transesophageal echocardiographic guidance at the end of the procedure.

References

1. David TE, Feindel CM.  An aortic valve-sparing operation for patients with aortic incompetence and aneurysm of the ascending aorta. J Thorac Cardiovasc Surg 1992;103: 617-621.
2. David TE, MD, Feindel CM, Bos J. Repair of the aortic valve in patients with aortic insufficiency and aortic root aneurysm.  J Thorac Cardiovasc Surg 1995;109:345-352.
3. Boodhwani  M, De Kerchov L, El Khoury G. Aortic root replacement using the reimplantation technique: tips and tricks.  Interactive CardioVasc Thorac Surg 2009;8:584–586
4. Svensson LG. Sizing for modified David’s reimplantation procedure. Ann Thorac Surg 2003;76:1751-1753.
5. De Paulis R, De Matteis GM, Nardi P, Scaffa R, Colella DF, Bassano C et al. One-year appraisal of a new aortic root conduit with sinuses of Valsalva. J Thorac Cardiovasc Surg 2002;123:33-39.
6. Tsagakis K. Benedik J. El Khoury G, Jakob H. Aortic Valve Repair: Method for intraoperative evaluation of valve geometry by angioscopy. J Thorac Cardiovasc Surg. DOI: 10.1016/j.jtcvs.2015.01.059