Morphometric criteria for optimal mini-j sternotomy in aortic valve replacement

Introduction. The mini-J sternotomy is a minimally invasive approach for aortic valve replacement. Despite its advantages, anatomical variability of the chest and the limited width of the operative field pose technical challenges. Morphometric standardization of the access geometry allows optimization of the balance between adequate surgical exposure and preservation of sternal stability. Objective. To evaluate the morphometric parameters of mini-J sternotomy in aortic valve replacement. Materials and methods. The study included 45 patients who underwent mini-J sternotomy in 2023–2024 at Sechenov University. Intraoperatively, the following parameters were measured: length of the vertical (Lᵥ) and horizontal (Lₕ) limbs of the incision, bend angle (α), depth of the J-curve (D), intercostal level of intersection (U), width of the operative window (W), and exposure index (EI = Aₚ/Sₛ). Correlation analysis was performed between morphometric parameters and clinical outcomes, including myocardial ischemia time, cardiopulmonary bypass duration, and blood loss. Results. Mean values were: Lᵥ = 66 ± 5 mm, Lₕ = 37 ± 4 mm, α = 108 ± 7°, D = 22 ± 3 mm, W = 60 ± 6 mm, EI = 0,72 ± 0,06. No conversions to full sternotomy occurred. Exposure index correlated with the lengths of the vertical (r = 0.61) and horizontal (r = 0.54) limbs. Lᵥ < 60 mm was associated with an 11 ± 4 min increase in ischemia time, α - 120° with higher risk of microfractures, and D - 28 mm with sternal instability. Conclusion. Mini-J sternotomy with parameters within recommended ranges provides optimal aortic root exposure, minimizes tissue trauma, and enhances procedural safety.