The Bentall procedure and valve-sparing root replacement are established surgical techniques for treating aortic root pathologies. The Bentall procedure is considered the standard approach, offering the possibility of replacing the aortic valve with either a mechanical or biological prosthesis, each with advantages and limitations regarding anticoagulation requirements or structural deterioration over time. Conversely, valve-sparing techniques are technically demanding, with a potential risk for early aortic insufficiency if the repair is unsuccessful.

This article presents a comparative analysis of mid- and long-term outcomes in aortic root replacement surgeries using valve-sparing techniques versus the Bentall-De Bono valved conduit replacement, conducted by the Weill Cornell Medicine team in New York.

The authors analyzed data from 1,635 patients who underwent aortic root replacement between 1997 and 2022. Among them, 473 patients received valve-sparing root replacement (VSRR) with a reimplantation technique, and 1,162 underwent composite valve graft (CVG) replacement. Cases with aortic dissection were excluded. To mitigate selection bias, the comparison utilized a propensity score-matched analysis.

The CVG group presented with more comorbidities and included a higher proportion of patients with bicuspid native valves. Intraoperative mortality was 0.4% for CVG and 0% for VSRR. The incidence of major postoperative complications was 2.9% (3.6% vs. 1.1%; p = 0.009). Ten-year survival was 93.1% with no significant differences. Aortic valve reinterventions were comparable between groups. However, differences were observed in the recurrence of moderate-severe aortic insufficiency, which was less prevalent in the CVG group (6.1% vs. 11.1%).

In conclusion, the article finds that with careful patient selection, both techniques offer excellent short- and mid-term outcomes.

COMMENTARY:

The authors undertake the challenging task of comparing two techniques for addressing a rare pathology by conducting a retrospective observational study in a high-volume center. However, these two interventions, while targeting the same pathology, are not typically intended for the same patient profiles. This distinction is acknowledged in the study, and to minimize selection bias, a propensity score-matched analysis was performed. This approach, combined with a large sample size, allowed the authors to achieve statistically significant results. Nevertheless, the conclusions should be interpreted cautiously.

Aortic root replacement with a valved conduit and coronary ostia reimplantation was initially described by Bentall and De Bono in 1968. Since then, this technique has undergone minor modifications to become the standard for treating aortic root aneurysms. As the native aortic valve is replaced, neither the native anatomy nor the level of valvular and annular calcification pose an obstacle, making this technique suitable for older patients with comorbidities, including renal insufficiency, bicuspid valves, and/or stenotic components, as reflected in this study’s findings.

Regarding prosthesis choice in CVG, there is a trend toward using biological prostheses in younger patients, paralleling the trend observed in isolated aortic valve replacement in our setting. The option for TAVI valve-in-valve offers the possibility of CVG with biological prostheses in younger patients.

Cardiac surgeons, driven by the goal to preserve anatomically healthy native aortic valves in cases of aortic root aneurysms, have developed valve-sparing root replacement techniques. Native valve preservation provides benefits, such as no anticoagulation requirements and improved resistance to infection. However, while any patient suitable for a valve-sparing procedure could undergo a Bentall procedure, not all Bentall candidates are eligible for valve-sparing surgery. Several valve-sparing root replacement techniques are in constant evolution.

Aortic remodeling, also known as the Yacoub procedure, involves attaching a festooned Dacron graft to the remaining sinus tissue around the aortic valve. The reimplantation technique, or David surgery, involves attaching a cylindrical graft to the aortic annulus and then securing the sinus remnants within the graft.

Miller and colleagues classified these techniques as follows:

• David-I: The original reimplantation using a cylindrical tubular graft.
• David-II: The classic Yacoub remodeling.
• David-III: A remodeling technique combined with synthetic annuloplasty to prevent annular dilation.
• David-IV: Reimplantation using a circumferentially pleated graft at the sinotubular junction (STJ), with the graft diameter sized to be 4 mm larger than the theoretical STJ diameter (based on subcommissural triangle height and native annular features), creating a more anatomically correct configuration at the STJ level.
• David-V: An even larger graft (6-8 mm) with narrowing at both ends to create pseudo-sinuses of Valsalva, which are crucial for restoring the hemodynamic function of the native valve.

Additionally, the less commonly performed Urbanski technique involves resecting each pathologic sinus and replacing it with a teardrop-shaped patch, while the “Florida sleeve” approach developed by Hess and colleagues allows a less invasive approach by placing an aortic graft over the root, suturing the native valve and coronary ostia, thus overcoming some technical challenges of aortic repair.

The reimplantation technique using a Valsalva graft preserves aortic root geometry, theoretically reducing recurrent aortic insufficiency. This is achieved as the aortic annulus is anchored by the Dacron graft, preventing further annular dilation. This technique is considered the most reliable among valve-sparing root replacement procedures and is the one used by the authors in this study. However, the specific technique subtype (David I, IV, or V) is not detailed, leaving open the question of whether one subtype may offer superior durability in terms of recurrent aortic insufficiency compared to CVG.

In this study, patients with bicuspid aortic valves were predominantly included in the CVG group (521 [44%] vs. 114 [24.1%]). In recent years, VSRR techniques have been applied to bicuspid valves. Future decision-making may benefit from standardizing criteria, as proposed by Brussels and Hamburg teams, based on cusp asymmetry classifications (e.g., symmetric with commissural angles of 160º-180º, asymmetric with angles of 140º-159º, and highly asymmetric with angles of 120º-139º) or other alterations that may influence the choice between techniques.

In summary, based on the results provided, both procedures yield excellent short- and long-term outcomes with follow-ups extending up to 10 years. VSRR is associated with a higher risk of recurrent aortic insufficiency, but no difference was found in reinterventions compared to CVG. This leads us to conclude that similar outcomes can be achieved with both techniques. Thus, individualized patient assessment should guide the choice of the best therapy. Nonetheless, further evidence on VSRR’s natural history beyond 10 years and how to manage cases involving bicuspid valves would further inform decision-making.

REFERENCE:

Ram E, Lau C, Dimagli A, Gaudino M, Girardi LN. Valve Sparing vs Composite Valve Graft Root Replacement: Propensity Score-Matched Analysis. Ann Thorac Surg. 2024 Jan;117(1):69-76. doi: 10.1016/j.athoracsur.2023.05.049.