Open aortic arch repair without circulatory arrest by frozen elephant trunk in Ishimaru zone 0.

BACKGROUND: Open arch surgery is technically demanding for the surgeon and surgically and biologically invasive for the patient, requiring a variably long period of hypothermic circulatory arrest. CASE PRESENTATION: Here we present a case of an elderly patient with chronic renal failure and multiple splanchnic artery disease successfully treated for a rupturing pseudoaneurysm of the aortic arch with a technique that we developed for particularly frail patients. The procedure includes: triple supra-aortic vessel perfusion; distal thoracic aorta antegrade perfusion; balloon endo-clamping of the descending aorta; and anastomosis of an off-the-shelf hybrid arch prosthesis in Ishimaru zone 0. These maneuvers allowed to maintain an extracorporeal circulation in the phase of distal anastomosis, instead of a period of circulatory arrest, employing just mild hypothermia: technical details are depicted and discussed also in comparison with other methods proposed in the literature. CONCLUSIONS: Being able to take advantage of both open surgery advancements and endovascular methods is the key to cardiovascular surgery success today in front of complex pathologies of the aorta: increasing safety and reducing invasiveness of therapeutic options may progressively extend surgical candidacy to the frailest patients.

Acute type A aortic dissection in bicuspid versus tricuspid aortic valve patients: focus on geometrical features of the aorta.

OBJECTIVES: This retrospective observational study aimed to assess the geometrical features, including diameters, length and angulation, of the ascending aorta with bicuspid and tricuspid aortic valve and to identify imaging markers potentially predicting whether aortopathy is likely to evolve chronically or to complicate with acute type A dissection. METHODS: Angio-computed-tomography scans of 354 patients (from 3 centres) with non-dilated (n = 97), aneurysmal (n = 100) or dissected aorta (n = 157) were reviewed. Diameters were measured at root, sinotubular junction, ascending, brachio-cephalic trunk origin; centreline lengths of the root and tubular tract and ascending-arch angle (between the ascending tubular tract axis and the proximal arch axis) were also measured. For 12 dissection patients, pre-dissection scans were available to investigate predisposing aortic geometry. Statistical analysis included: tricuspid versus bicuspid comparisons in each subgroup; univariate and multivariate analyses of the predictors of ascending-arch angle narrowing; and estimation of diagnostic accuracy of the angle parameter. RESULTS: Diameters and lengths were similar between aneurysms and dissections, whereas dissections showed a significant ascending-arch angle narrowing (117 ± 13° in tricuspid, 115 ± 14° in bicuspid) compared to non-dilated and aneurysmal aortas (all P < 0.001). The best angle cut-off to discriminate dissection patients was 131° (96% sensitivity). In patients with a pre-dissection scan, Asc-Arch narrowing was already present before dissection. In non-dissected aortas over-angulation was predicted by root phenotype dilatation both in bicuspid and tricuspid patients. Bicuspid patients with non-dilated aorta showed elongated root (P = 0.027), a feature significantly correlated with Asc-Arch angle narrowing (P = 0.008). CONCLUSIONS: The ascending-arch angle is promising as a risk marker for dissection to be used along with diameter. Its narrowing seems to be associated with elongation of the root, a feature that bicuspid patients can show even without significant dilatation. Root phenotype aortopathy may be at higher risk also with tricuspid aortic valve.

Survival and Recurrence of Endocarditis following Mechanical vs. Biological Aortic Valve Replacement for Endocarditis in Patients Aged 40 to 65 Years: Data from the INFECT-Registry.

BACKGROUND: Infective endocarditis (IE) is a serious disease, and in many cases, surgery is necessary. Whether the type of prosthesis implanted for aortic valve replacement (AVR) for IE impacts patient survival is a matter of debate. The aim of the present study is to quantify differences in long-term survival and recurrence of endocarditis AVR for IE according to prosthesis type among patients aged 40 to 65 years. METHODS: This was an analysis of the INFECT-REGISTRY. Trends in proportion to the use of mechanical prostheses versus biological ones over time were tested by applying the sieve bootstrapped t-test. Confounders were adjusted using the optimal full-matching propensity score. The difference in overall survival was compared using the Cox model, whereas the differences in recurrence of endocarditis were evaluated using the Gray test. RESULTS: Overall, 4365 patients were diagnosed and operated on for IE from 2000 to 2021. Of these, 549, aged between 40 and 65 years, underwent AVR. A total of 268 (48.8%) received mechanical prostheses, and 281 (51.2%) received biological ones. A significant trend in the reduction of implantation of mechanical vs. biological prostheses was observed during the study period (p < 0.0001). Long-term survival was significantly higher among patients receiving a mechanical prosthesis than those receiving a biological prosthesis (hazard ratio [HR] 0.546, 95% CI: 0.322-0.926, p = 0.025). Mechanical prostheses were associated with significantly less recurrent endocarditis after AVR than biological prostheses (HR 0.268, 95%CI: 0.077-0.933, p = 0.039). CONCLUSIONS: The present analysis of the INFECT-REGISTRY shows increased survival and reduced recurrence of endocarditis after a mechanical aortic valve prosthesis implant for IE in middle-aged patients.

[Bicuspid aortic valve and its complications: from molecules to surgery]. / La bicuspidia aortica e le sue complicanze: dalle molecole al bisturi.

Bicuspid aortic valve is a relevant condition to the epidemiology of degenerative (stenosis, regurgitation) and infective (endocarditis) aortic valve disease. This review will address the topics of treatment of those valvular complications, focusing on the peculiar aspects distinguishing them from tricuspid aortic valve diseases, in particular transcatheter treatment of stenosis, valve repair/sparing surgery for regurgitation, prevention of endocarditis. Bicuspid aortopathy represents a clinical entity with remarkable prognostic, and likely also pathogenetic, heterogeneity. A deeper understanding of the tissue and molecular factors as well as flow-related and biomechanical aspects of its development and progression could help guiding better risk stratification (identification of more severe forms, prevention of acute aortic dissection), allowing for a personalized therapeutic approach. The present review will also summarize the state of the art about bicuspid aortopathy pathogenesis, moreover forwarding new hypotheses for the interpretation of the many sparse pieces of evidence currently available.

Implications of abnormal ascending aorta geometry for risk prediction of acute type A aortic dissection.

OBJECTIVES: Recently, increased length of the ascending aorta has been suggested as a possible risk factor for acute type A aortic dissection (ATAAD). Our goal was to identify measurable aortic geometrical characteristics associated with elongation that could differentiate ATAAD from uncomplicated aortic dilation (>45 mm). METHODS: In angiographic computed tomography scans performed in 180 patients having cardiac surgery, aortic diameters, root length, length of the ascending aorta at both the centreline and the greater curvature (convexity) and the root-ascending (root-asc) angle (that between the root axis and the axis of the ascending tract) and the ascending-arch (asc-arch) angle (that between the axis of the ascending aorta and the arch axis) were measured and compared among 3 patient groups: normal aorta (diameter < 45 mm), dilation/aneurysm (>45 mm) and ATAAD. Correlations between diameters and angles, diameters and lengths and lengths and angles were analysed; multivariable analysis including geometrical factors was performed to identify independent predictors of ATAAD. RESULTS: Both patients with aneurysms and patients with ATAAD showed significantly elongated ascending aortas (P < 0.001 vs normal). However, in the aneurysms, the root-asc angle (136° ± 20° vs 147° ± 17°; P < 0.001) and in ATAAD the asc-arch angle were uniquely narrower than that in the normal aorta (116° ± 11° vs 132° ± 19°; P < 0.001). All patients with an ATAAD had an asc-arch angle ≤130°. Both in patients with ATAAD and in those without ATAAD, narrowing of the asc-arch angle was associated with elongation of the root segment (P < 0.001). In multivariable analysis, the asc-arch angle and the total length of the ascending aorta (root + tubular) were significant predictors of ATAAD. CONCLUSIONS: The asc-arch angle is a promising measurement that could help predict aortic dissection along with aortic diameter and length: further verification is warranted.

Risk Stratification in Bicuspid Aortic Valve Aortopathy: Emerging Evidence and Future Perspectives.

The current management of aortic dilatation associated with congenital bicuspid aortic valve (bicuspid aortic valve aortopathy) is based on dimensional parameters (diameter of the aneurysm, growth of the diameter over time) and few other criteria. The disease is however heterogeneous in terms of natural and clinical history and risk of acute complications, ie aortic dissection. Dimensional criteria are now admitted to have limited value as predictors of such complications. Thus, novel principles for risk stratification have been recently investigated, including phenotypic criteria, flow-related metrics, and circulating biomarkers. A systematization of the typical anatomoclinical forms that the aortopathy can assume has led to the identification of the more severe root phenotype, associated with higher risk of progression of the aneurysm and possible higher aortic dissection risk. Four-dimensional-flow magnetic resonance imaging studies are searching for potentially clinically significant metrics of flow derangement, based on the recognized association of local abnormal shear stress with wall pathology. Other research initiatives are addressing the question whether circulating molecules could predict the presence or, more importantly, the future development of aortopathy. The present review summarizes the latest progresses in the knowledge on risk stratification of bicuspid aortic valve aortopathy, focusing on critical aspects and debated points.

Latest Advances in the Treatment of Bicuspid Aortic Valve.

Bicuspid aortic valve (BAV) is the most frequent congenital cardiac defect, and affects 0.5-2% of live births. Almost half of BAV subjects develop different degrees of valvular dysfunction during their lifetime. In both echocardiographic cohorts and surgical series, pure aortic regurgitation is significantly less common than stenosis. BAV also carries a higher risk of aortic aneurysm, aortic dissection or aortic valve endocarditis compared to the general population. Once aortic insufficiency reaches threshold criteria for surgical treatment, the valve has to be replaced (conventional aortic valve replacement, the outcomes of which are well established) or repaired. Repair techniques for regurgitant BAVs and valve-sparing surgery for BAV-related aneurysms have evolved remarkably over the past several decades. Improvements in our understanding of the mechanisms of normal and pathological BAV function and the development of criteria and techniques to address all the pathologic components of valve and root have supported better repair results. The more frequent stenotic BAV is treated by prosthetic valve replacement or, in recent years, by trans-catheter prosthetic replacement (TAVR), the application of which in the BAV setting is increasing, as with tricuspid aortic valve (TAV) stenosis, especially since indications are extended to medium-risk patients. It has been reported that the risk of paravalvular leak and/or prosthesis malposition is higher in BAV than in TAV stenosis, due to the more elliptical annulus and the calcified raphe of the bicuspid valve. New-generation balloon-expandable devices seem to be capable of lowering the rates of these complications. As research in this field keeps filling in the gaps in current knowledge about bicuspid malformation and its common complications, further advancements in their treatment are awaited.

The science of BAV aortopathy.

The aortopathy associated with bicuspid aortic valve (BAV) is an epidemiologically relevant source of chronic and acute aortic disease (aneurysm and dissection). However, its pathogenesis is still the object of scientific uncertainties and debates. Indeed, the mechanisms determining the diseases of the ascending aorta in BAV patients are most likely complex and multifactorial, i.e. resulting from variable modes of interplay between genetic and hemodynamic factors. Although few scientific studies have so far taken into adequate account this complexity, leaving the precise sequence of pathogenetic events still undiscovered, the accumulated evidence from previous research approaches have at least brought about important insights. While genetic studies have so far identified variants relevant to either valve malformation or aortic complications (including those in the genes NOTCH1, TGFBR2, ACTA2, GATA5, NKX2.5, SMAD6, ROBO4), however each explaining not more than 5% of the study population, other investigations have thoroughly described both the flow features, with consequent forces acting on the arterial wall (including skewed flow jet direction, rotational flow, wall shear stress), and the main changes in the molecular and cellular wall structure (including extracellular matrix degradation, smooth muscle cell changes, oxidative stress, unbalance of TGF-ß signaling, aberrant endothelial-to-mesenchymal transition). All of this evidence, together with the recognition of the diverse phenotypes that the aortopathy can assume in BAV patients, holding possible prognostic significance, is reviewed in this chapter. The complex and multifaceted body of knowledge resulting from clinical and basic science studies on BAV aortopathy has the potential to importantly influence modes of clinical management of this disease in the near future.