Development of a Simple Analytical Model to Facilitate Preoperative Surgical Planning in Valve-Sparing Aortic Root Replacement

Dominic P Recco; Shannen B Kizilski; Wen Zhang; Nicholas E Kneier; Patrick D Earley; David M Hoganson; Christopher W Baird; Peter E Hammer

doi:10.1007/s10439-024-03593-y

Development of a Simple Analytical Model to Facilitate Preoperative Surgical Planning in Valve-Sparing Aortic Root Replacement

Ann Biomed Eng. 2024 Dec;52(12):3264-3279. doi: 10.1007/s10439-024-03593-y. Epub 2024 Aug 6.

Authors

Dominic P Recco^{1

2}, Shannen B Kizilski^{1

2}, Wen Zhang¹, Nicholas E Kneier¹, Patrick D Earley¹, David M Hoganson^{1

2}, Christopher W Baird^{1

2}, Peter E Hammer^{3

4}

Affiliations

¹ Department of Cardiac Surgery, Boston Children's Hospital, Boston, MA, 02115, USA.
² Harvard Medical School, Boston, MA, 02115, USA.
³ Harvard Medical School, Boston, MA, 02115, USA. Peter.Hammer@childrens.harvard.edu.
⁴ Department of Cardiac Surgery, Boston Children's Hospital, 300 Longwood Avenue, Bader, 2nd Floor, Boston, MA, 02215, USA. Peter.Hammer@childrens.harvard.edu.

PMID: 39107489
DOI: 10.1007/s10439-024-03593-y

Abstract

Purpose: Valve-sparing root replacement (VSRR) is attractive for aortic root dilation as it preserves the native aortic valve (AoV). Low effective height (eH) after reconstruction is a risk factor for repair failure and reoperation. We developed and validated a quantitative AoV repair strategy to reliably restore normal valve proportions to promote long-term function.

Methods: Normal AoV proportions were used to derive geometric relationships for sinotubular junction diameter (D_STJ), free edge length (FEL), free edge angle, and commissure height. These relationships informed two models for predicting eH following VSRR: (1) assuming valve symmetry and (2) accounting for valve asymmetry. Porcine heart (n = 6) ex vivo validation was performed under 4 VSRR scenarios: "Ideal" (tube graft size targeting FEL/D_STJ = 1.28), "Oversized" (one graft size larger than Ideal), "Undersized" (two sizes smaller), and "Undersized + Plicated" (FEL/D_STJ = 1.28 restored with leaflet plication).

Results: Our analytical models predicted eH using preoperative measurements and estimated reconstructed dimensions. The Oversized graft exhibited similar eH to Ideal but higher regurgitation in the ex vivo model, whereas the Undersized graft demonstrated lower eH and regurgitation. Plication in the Undersized graft restored valve function (regurgitation & eH) similar to Ideal in the ex vivo model and above Ideal in the analytical models. Both analytical models predicted ex vivo eH well except in the Oversized and Undersized + Plicated conditions.

Conclusion: Utilizing measurements from preoperative imaging and simple mathematical models, patient-specific operative plans for VSRR can be created by estimating valve dimensions necessary to achieve favorable valve features post-repair. Clinical application of this approach promises to improve consistency in achieving optimal long-term dimensions and durability.

Keywords: Aortic cusp geometry; Aortic valve; Aortic valve repair; Effective height.

MeSH terms

Animals
Aorta / surgery
Aortic Valve* / surgery
Humans
Models, Cardiovascular*
Swine