Unilateral versus bilateral cerebral perfusion during aortic surgery for acute type A aortic dissection: a multicentre study

OBJECTIVES

The aim of this retrospective multicentre study was to investigate and compare clinical outcomes of unilateral and bilateral antegrade cerebral perfusion (ACP) strategies on cerebral protection during surgery for type A aortic dissection.

METHODS

Data from 646 patients who underwent surgical repair of thoracic type A aortic dissection using unilateral and bilateral ACP with moderate hypothermic circulatory arrest in 3 cardiac surgical institutions between 2008 and 2018 were analysed. Propensity matching was performed to assess which technique ensured better outcomes.

RESULTS

Unilateral and bilateral ACP techniques were performed in 250 (39%) and in 396 (61%) patients, respectively. Propensity score analysis identified 189 matched pairs. In the matched cohort, the lowest core temperature was 27.5°C and 28°C in the bilateral and unilateral groups, respectively (P < 0.001). The unilateral technique required significantly shorter aortic cross-clamp and cardiopulmonary bypass times than bilateral technique [82 min vs 100 min (P < 0.001); 170 min vs 195 min (P < 0.001)]. The 30-day mortality was comparable (P = 0.325). The bilateral group reported a significantly higher incidence of permanent neurologic deficits (P < 0.001), left brain hemisphere stroke (P = 0.007) and all-combined complications (P < 0.001). Ten-year survival was comparable (P = 0.45).

CONCLUSIONS

Unilateral and bilateral ACP are both valid brain protection strategies in the landscape of aortic arch surgery. While admitting all the study limitations, unilateral technique could offer some clinical advantages.

CLINICAL REGISTRATION NUMBER

76049.

Left ventricle reconstruction and heartmate3 implantation. The "double patch technique"

BACKGROUND

HeartMate 3 is a left ventricular assist device, composed of a centrifugal pump. It can be applied as a myocardial recovery, a bridge to transplant, or a destination therapy, in the treatment of patients with left ventricular heart failure.

METHODS

Herein we describe a technique applied against a giant aneurysmal dilatation, which combines a surgical device implantation and a left ventricular reconstruction using a double patch.

RESULTS

The patch minimizes thrombotic risk thanks to its internal bovine pericardium layer, which is in contact with blood.

CONCLUSIONS

The outlined technique is relatively reproducible and safe in a selected group of patients, as it employs a high-quality device and enables the restoration of an appropriate ventricular geometry.

Rapid-deployment aortic valve replacement in high-risk patients with severe endocarditis

BACKGROUND

Surgical management of aortic valve endocarditis in high risk patients is controversial and the ideal treatment has not been found yet. We describe a selected series of eight patients treated with rapid-deployment aortic valve prosthesis as a therapeutic solution for minimizing the risks associated with annulus manipulation in case of severe aortic infective endocarditis.

METHODS

Eight consecutive patients (five men and three women) with a mean age of 74.3±7.2 years, mean logistic EuroSCORE II of 16.0%±0.1%, affected by aortic native (1 patient), or prosthetic valve endocarditis (7 patients), were treated with Edwards Intuity Elite implantation. Hemodynamic performance and infective data were collected pre-, intra-, and postoperatively with a mean follow-up of 2.7±0.7 years.

RESULTS

One case of in-hospital mortality was noted. None of the patients had any embolic or infective complication postoperatively. The cardiopulmonary bypass and aortic cross-clamp times were 148.4±41.6 and 90.5±25.3 min, respectively. The postoperative echocardiographic controls indicated a mean transvalvular gradient of 16.7±3.0 mmHg and one case of paravalvular leaks (2 +). Two patients underwent epigastric permanent pacemaker implantation. During the follow-up, seven patients were alive, with no evidence of symptoms or recurrences of endocarditis or embolic episodes. No new paravalvular leaks were noted, and the mean gradient on the valves was 12.4±3.4 mmHg.

CONCLUSIONS

Rapid deployment aortic valve replacement in selected very high-risk patients affected by infective endocarditis could be a reasonable choice with acceptable results. However, further studies are needed to confirm these results.

Planar cell polarity genes frizzled4 and frizzled6 exert patterning influence on arterial vessel morphogenesis

Quantitative analysis of the vascular network anatomy is critical for the understanding of the vasculature structure and function. In this study, we have combined microcomputed tomography (microCT) and computational analysis to provide quantitative three-dimensional geometrical and topological characterization of the normal kidney vasculature, and to investigate how 2 core genes of the Wnt/planar cell polarity, Frizzled4 and Frizzled6, affect vascular network morphogenesis. Experiments were performed on frizzled4 (Fzd4^-/-) and frizzled6 (Fzd6^-/-) deleted mice and littermate controls (WT) perfused with a contrast medium after euthanasia and exsanguination. The kidneys were scanned with a high-resolution (16 μm) microCT imaging system, followed by 3D reconstruction of the arterial vasculature. Computational treatment includes decomposition of 3D networks based on Diameter-Defined Strahler Order (DDSO). We have calculated quantitative (i) Global scale parameters, such as the volume of the vasculature and its fractal dimension (ii) Structural parameters depending on the DDSO hierarchical levels such as hierarchical ordering, diameter, length and branching angles of the vessel segments, and (iii) Functional parameters such as estimated resistance to blood flow alongside the vascular tree and average density of terminal arterioles. In normal kidneys, fractal dimension was 2.07±0.11 (n = 7), and was significantly lower in Fzd4^-/- (1.71±0.04; n = 4), and Fzd6^-/- (1.54±0.09; n = 3) kidneys. The DDSO number was 5 in WT and Fzd4^-/-, and only 4 in Fzd6^-/-. Scaling characteristics such as diameter and length of vessel segments were altered in mutants, whereas bifurcation angles were not different from WT. Fzd4 and Fzd6 deletion increased vessel resistance, calculated using the Hagen-Poiseuille equation, for each DDSO, and decreased the density and the homogeneity of the distal vessel segments. Our results show that our methodology is suitable for 3D quantitative characterization of vascular networks, and that Fzd4 and Fzd6 genes have a deep patterning effect on arterial vessel morphogenesis that may determine its functional efficiency.

Impella 5.0 microaxial pump as a right ventricular assist device after surgical treatment of posterior post-infarction ventricular septal defect

The Impella Recover LP 5.0 is an aortic transvalvular microaxial pump designed to unload the left ventricle and to ensure a systemic flow in severe left ventricular dysfunction. We propose a new suggestion for the Impella 5.0 as a temporary right ventricular assist device after the surgical treatment of a posterior post-infarction ventricular septal defect.