Totally Endoscopic Aortic Valve Replacement Using a Longitudinal Incision for a Type 0 Bicuspid Aortic Valve

A 70-year-old man with a remote history of asymptomatic aortic regurgitation identified in his 30s was referred after a new systolic murmur and ECG abnormalities were detected during a routine evaluation. He had no significant comorbidities or prior cardiac surgery. On admission, vital signs were stable (BP 132/56 mmHg, HR 58 bpm, SpO₂ 98%), and his functional status was New York Heart Association class II.

Preoperative ECG demonstrated atrial fibrillation with a complete right bundle branch block pattern. Transthoracic echocardiography confirmed severe aortic stenosis with a maximum velocity of 5.0 m/s, mean pressure gradient of 55 mmHg, and calculated aortic valve area of 0.70 cm², with preserved left ventricular ejection fraction of 61% and mild concomitant aortic regurgitation.

Figure 1

Preoperative ECG — Atrial Fibrillation with Complete Right Bundle Branch Block

The 12-lead ECG shows an irregularly irregular rhythm with absent P waves consistent with atrial fibrillation, superimposed on a complete right bundle branch block pattern characterized by widened QRS, terminal R waves in V1–V2, and slurred S waves in leads I, V5–V6. This conduction pattern is relevant for operative planning given the risk of complete heart block during annular suturing in a calcified or distorted outflow tract.

CT imaging was central to surgical planning and revealed a markedly elliptical annulus — the anatomical hallmark of type 0 bicuspid aortic valve (BAV), which lacks a raphe and tends toward large, non-circular annular geometry. CT measurements showed: ascending aorta 40×37 mm, sinotubular junction 39×29 mm, sinuses of Valsalva 41×28 mm, annulus 39×27 mm, and LVOT 41×25 mm. Both femoral and external iliac arteries measured below 9 mm in diameter, excluding a transfemoral TAVR approach. Coronary angiography demonstrated no obstructive coronary artery disease.

Figure 2

Preoperative CT — Elliptical Annular Anatomy in Type 0 BAV

Cross-sectional CT images at the sinotubular junction (A), sinuses of Valsalva (B), left ventricular outflow tract (C), and three-dimensional aortic reconstruction (D). The elliptical shape of the annulus — with a major-to-minor axis ratio characteristic of type 0 BAV — creates two specific surgical challenges: (1) standard circular sizers may underestimate the true annular dimension, and (2) circular prosthetic expansion requires annular remodeling with strategic suture placement to prevent paravalvular leak.

The patient strongly preferred a minimally invasive approach. TAVR was considered unsuitable given the elliptical non-calcified annulus (high paravalvular leak risk) and the small access vessels. Totally endoscopic AVR (TE-AVR) using a novel longitudinal aortotomy was selected. Through a 4K 3D endoscopic approach, a longitudinal aortotomy approximately 4 cm in length was created in the ascending aorta, oriented vertically toward the non-coronary sinus and terminating approximately 1 cm proximal to the sinotubular junction. This provided direct endoscopic visualization of the elliptical type 0 bicuspid annulus.

Figure 3

Intraoperative Endoscopic Views — Hybrid Suture Technique

Panels show the operative sequence: (A) Direct endoscopic exposure of the type 0 bicuspid valve through the longitudinal aortotomy, confirming the elliptical annulus and absence of a raphe. (B) Sizing with a 29-mm INSPIRIS RESILIA sizer confirming adequate annular dimensions for a large bioprosthesis. (C) Placement of four everting mattress sutures with pledgets at the nadirs and commissures (clock positions 0, 3, 6, and 9 o'clock) — the "hybrid" element designed to circularize the elliptical annulus. (D) Final appearance after implantation of the 29-mm INSPIRIS bioprosthesis, showing satisfactory seating without residual regurgitation.

Native cusps were excised completely. A hybrid suture strategy was employed: four everting mattress sutures with pledgets at the four nadir/commissure positions (clock 0, 3, 6, 9), and interrupted sutures at the remaining eight positions. This combination was designed to redistribute annular tension and promote circularization of the ellipse. A 29-mm INSPIRIS RESILIA bioprosthesis (Edwards Lifesciences) was implanted without difficulty. No intraoperative complications occurred.

Postoperative recovery was rapid. The patient was extubated on postoperative day (POD) 1, transferred from the high-care unit on POD 2, and ambulated with greater than 4 METs by discharge on POD 7. Postoperative TTE demonstrated an excellent result: AVA 2.32 cm², maximum gradient 11 mmHg, mean gradient 6 mmHg, and no residual paravalvular or transvalvular aortic regurgitation (physiologic intra-prosthetic washout jets were noted but are not classified as AR). LVEF improved slightly from 61% to 66%.

Figure 4

Postoperative Echocardiography — Excellent Hemodynamic Result

Panel A: Color Doppler imaging demonstrates only trivial transvalvular leakage with no paravalvular regurgitation. Panel B: Continuous-wave Doppler across the prosthetic aortic valve shows peak velocity in the 1 m/s range with maximum gradient 11 mmHg and mean gradient 6 mmHg — dramatically reduced from pre-operative values of 98 mmHg maximum and 55 mmHg mean. This degree of gradient reduction confirms excellent prosthesis-patient matching for the 29-mm bioprosthesis in a large annulus.

CT performed on POD 6 confirmed the key structural outcome: the previously elliptical annulus had remodeled to a near-circular configuration — direct evidence that the hybrid suture strategy and longitudinal aortotomy approach had achieved the intended annular circularization.

Figure 5

CT Curved Planar Reconstruction — Annular Circularization

Pre- (A) and post-operative (B) CT images at the level of the aortic annulus. Panel A shows the characteristic elliptical shape of the type 0 BAV annulus prior to surgery, with the major axis significantly wider than the minor axis. Panel B demonstrates near-circular remodeling of the annulus following the hybrid suture technique — the key structural goal of the operation, as residual elliptical deformation would predispose to paravalvular leak and suboptimal prosthetic expansion.

Discussion

Type 0 bicuspid aortic valve — defined by a raphe-less, symmetric two-cusp morphology with an inherently elliptical annulus — represents a specific anatomical challenge for both transcatheter and surgical valve replacement. In TAVR, the elliptical annulus resists circular expansion of the prosthetic frame, resulting in oval deformation that creates geometric gaps at the leaflet coaptation zones, higher rates of paravalvular leak, and residual transvalvular gradients. The longitudinal aortotomy described in this case addresses this challenge for endoscopic surgery by providing a direct vertical line of sight from the aortotomy down to the annular plane, enabling accurate sizing, secure suture placement at all quadrants, and implantation of a large prosthesis that would be difficult to position through a transverse or oblique incision. The hybrid suture strategy — everting mattress at the four nadir positions combined with interrupted sutures at the remaining eight — achieves tensional redistribution that actively reshapes the ellipse toward circularity, as confirmed by post-operative CT.

This case adds to the nascent literature on surgical strategies specifically optimized for type 0 BAV geometry. It demonstrates that TE-AVR, when combined with an exposure-driven longitudinal aortotomy, can achieve annular circularization, large-prosthesis implantation (29-mm), and near-zero residual regurgitation in a totally endoscopic setting — outcomes that translate clinically to very low transvalvular gradients and preserved LVEF at discharge. The patient's rapid functional recovery (ambulating at >4 METs by POD 7) underscores the systemic benefits of minimally invasive approaches in patients who strongly prefer them. Longer follow-up is needed to validate annular durability and assess for late paravalvular leak, but the early results are highly encouraging for a technique that may offer an attractive alternative to TAVR in younger BAV patients with elliptical anatomy unsuitable for transcatheter approaches.