The influence of operative techniques on the outcomes of bicuspid aortic valve disease and aortic dilatation

Patients with Bicuspid Aortopathy and Aortic Dilatation

(1) Background: Bicuspid aortic valve (BAV) is the most frequent congenital cardiac disease. Alteration of ascending aorta diameter is a consequence of shear stress alterations due to haemodynamic abnormalities developed from inadequate valve cusp coaptation. (2) Objective: This narrative review aims to discuss anatomical, pathophysiological, genetical, ultrasound, and radiological aspects of BAV disease, focusing on BAV classification related to imaging patterns and flux models involved in the onset and developing vessel dilatation. (3) Methods: A comprehensive search strategy was implemented in PubMed from January to May 2022. English language articles were selected independently by two authors and screened according to the following criteria. (4) Key Contents and Findings: Ultrasound scan is the primary step in the diagnostic flowchart identifying structural and doppler patterns of the valve. Computed tomography determines aortic vessel dimensions according to the anatomo-pathology of the valve. Magnetic resonance identifies hemodynamic alterations. New classifications and surgical indications derive from these diagnostic features. Currently, indications correlate morphological results, dissection risk factors, and genetic alterations. Surgical options vary from aortic valve and aortic vessel substitution to aortic valve repair according to the morphology of the valve. In selected patients, transcatheter aortic valve replacement has an even more impact on the treatment choice. (5) Conclusions: Different imaging approaches are an essential part of BAV diagnosis. Morphological classifications influence the surgical outcome.

Progress in surgical interventions for aortic root aneurysms and dissections

INTRODUCTION

: The aortic root is a uniquely sensitive region as it anatomically encompasses the aortic valve leaflets and gives origin to the coronary arteries. These associated structures, in addition to the aortic tube, itself, add immensely to the complexity of replacing this segment when it is aneurysmal or dissected. Given this complexity, many contemporary choices for treatment of aortic root aneurysms have evolved over the past few decades.

AREAS COVERED

The aim of this study was to provide an updated review of the literature regarding various surgical options for management of aortic root aneurysmal disease. A systematic search in Pubmed database was performed for articles related to various aortic root surgeries and outcomes published between 1998 to 2020.

EXPERT OPINION

: For multiple technical options in aortic root replacement surgery, decades of surgical investigation and development have shown favorable results, which provide a formidable armamentarium to be used at the discretion of the surgeon to suit various patient anatomic patterns and risk profile-while still durably controlling the aortic pathology and protecting from recurrence, valve dysfunction, progressive dilatation, and aortic dissection.

Temporal Trends and Outcomes of Elective Thoracic Aortic Repair and Acute Aortic Syndromes in Bicuspid Aortic Valves: Insights from a National Database

INTRODUCTION

There is paucity of data on the outcomes of hospitalization for bicuspid aortic valve (BAV)-related aortopathies.

METHODS

We queried the NIS database (2012-2016) for hospitalizations for elective thoracic aortic repair or acute aortic syndrome (AAS) among those with BAV versus trileaflet aortic valve (TAV).

RESULTS

Our analysis yielded 38,010 hospitalizations for elective aortic repair, of whom 34.4% had BAV, as well as 81,875 hospitalizations for thoracic AAS, of whom 1.1% had BAV. Hospitalizations for BAV were younger and had fewer comorbidities compared with their TAV counterparts. The number of hospitalizations for BAV during the observational period was unchanged. After propensity matching, elective aortic repair for BAV was associated with lower mortality (0.5% versus 1.7%, odds ratio = 0.28; 95% CI 1.5-0.50, p < 0.001), use of mechanical circulatory support, acute stroke, and shorter length of hospital stay compared with TAV. After propensity matching, AAS among those with BAV had a greater incidence of bleeding events, blood transfusion, cardiac tamponade, ventricular arrhythmias, and a longer length of hospital stay compared with TAV. Among those with BAV, predictors of lower mortality if undergoing elective aortic repair included larger hospitals and teaching hospitals. Predictors of higher mortality in patients with AAS included heart failure, chronic kidney disease, and coronary artery disease.

CONCLUSION

Data from a national database showed no change in the number of hospitalizations for BAV-related aortopathy, with relatively lower incidence of AAS. Compared with TAV, elective aortic repair for BAV is associated with lower mortality, while BAV-related AAS is associated with higher in-hospital complications.

Suture reduction of the borderline ascending aortic dilatation during aortic valve replacement

BACKGROUND

This study was conducted to evaluate the efficacy of simple suture reduction of the ascending aorta(SRA) performed with aortic valve replacement(AVR) in patients with borderline ascending aortic dilatation(45-50mm).

METHODS

98 patients (ascending aortic diameter=47.7±3.4mm) who underwent concomitant SRA with AVR were enrolled. Median follow-up duration was 83 (interquartile=27,173) months. Computed tomographic angiography(CTA) follow-up was performed at 71(47,149) months after surgery(n=69). At least two CTA scans were performed in 34 patients (interval=63[46,156] months). Early and long-term outcomes were evaluated, and dilatation rate (mm/year) of the repaired aorta was analyzed. Major adverse aortic events(MAEs) were defined as death related to aortic events, including sudden death, aortic rupture or dissection, aortic reoperation and recurrent aortic aneurysm(>45mm).

RESULTS

Early mortality rate was 2.0%. No patients had postoperative complications associated with SRA. A recurrent aortic aneurysm(>45mm) was found in 9 patients, but none of the patients had an ascending aorta diameter>50mm. A multivariable analysis demonstrated that neither preoperative diameter of the ascending aorta nor bicuspid valve was associated with dilatation of the repaired aorta. Co-existing coronary artery disease was associated with both recurrent aneurysm and increased dilatation rate after SRA. There were 2 cases of sudden death and no one suffered from aortic dissection, rupture or aortic reoperation. Ten- and 20-year freedom rates from MAE were 90.3% and 79.3%, respectively.

CONCLUSIONS

Concomitant SRA might be a safe and effective surgical alternative to ascending aorta replacement in AVR patients with borderline ascending aortic dilatation regardless of aortic valve pathology.

Natural history and outcomes of non-replaced aortic sinuses in patients with bicuspid aortic valves

BACKGROUND

Enlargement of the sinus of Valsalva (SOV) is common in patients with bicuspid aortic valves (BAV), and management at the time of aortic valve replacement (AVR) and concomitant ascending aorta replacement/repair is controversial.

METHODS

Between January 2000 and July 2017, 400 patients with BAV underwent AVR and concomitant ascending aorta repair (79%, graft replacement; 21%, aortoplasty). To assess the impact of the initial SOV dimension on future dilatation and outcomes, patients were stratified into two groups: SOV<40mm (n=209) and SOV≥40mm (n=191).

RESULTS

Patients with SOV≥40 mm were older, and more often male. At a median follow-up of 8.1 years (IQR 7.4-9.1), 6 patients underwent reoperations on the ascending or sinus portion of the aorta due to aneurysmal dilatation; enlargement of the sinus was the primary indication for operation in one patient. Adjusted analysis showed that baseline SOV and SOV dimension over time were not associated with late outcomes. A gradual increase in SOV diameter over time was identified (P=0.004). Patients with smaller baseline SOV diameters showed an initial early decrease in diameter followed by gradual increase, while those with larger baseline diameters had a stable early phase followed by gradual dilatation.

CONCLUSIONS

Ascending aorta replacement may lead to an initial remodeling/stabilizing effect on the spared bicuspid aortic root, which is more pronounced in patients with lower SOV diameters. In addition, our data demonstrate that the retained aortic sinuses enlarge slowly, and within the limited follow-up of our study, SOV diameter was not a risk factor for survival or reoperation.

Congenital Aortic Valve Stenosis

Aortic valve stenosis in children is a congenital heart defect that causes fixed form of hemodynamically significant left ventricular outflow tract obstruction with progressive course. Neonates and young infants who have aortic valve stenosis, usually develop congestive heart failure. Children and adolescents who have aortic valve stenosis, are mostly asymptomatic, although they may carry a small but significant risk of sudden death. Transcatheter or surgical intervention is indicated for symptomatic patients or those with moderate to severe left ventricular outflow tract obstruction. Many may need reintervention.

Clinical and pathophysiological aspects of bicuspid aortic valve disease

A bicuspid aortic valve is not only a common congenital heart defect but also an enigmatic condition that can cause a large spectrum of diseases, such as aortic valve stenosis and severe heart failure in newborns whereas aortic dissection in adults. On the contrary, a bicuspid aortic valve can also occur with normal function throughout life and never need treatment. Numerous genetic mechanisms are involved in the abnormal cellular functions that may cause abnormal development of the aortic valve during early foetal life. As several chromosomal disorders are also associated with a bicuspid valve, there does not appear to be an apparent common trigger to the abnormal development of the aortic valve. The clinical care of the bicuspid aortic valve patient has been changed by a significant body of evidence that has improved the understanding of the natural history of the disease, including when to best intervene with valve replacement and when to provide prophylactic aortic root surgery. Moreover, as bicuspid valve disease is also part of various syndromes, we can identify high-risk patients in whom a bicuspid valve is much more unfavourable than in the normal population. This review provides an overview of all aspects of the bicuspid aortic valve condition and gives an updated perspective on issues from pathophysiology to clinical care of bicuspid aortic valve disease and associated aortic disease in asymptomatic, symptomatic, and pregnant patients, as well as our viewpoint on population screening.

The aortic root does not dilate over time after replacement of the aortic valve and ascending aorta in patients with bicuspid or tricuspid aortic valves

OBJECTIVE

Whether the aortopathy associated with bicuspid aortic valve (BAV) disease occurs secondary to genetic or hemodynamic factors remains controversial. In this article we describe the natural history of the aortic root in patients with bicuspid versus tricuspid aortic valves (TAVs) after replacement of the aortic valve and ascending aorta.

METHODS

From 1990 to 2010, 406 patients (269 BAV, 137 TAV) underwent aortic valve and ascending aorta replacement at a single institution. Patients with aortic dissection, endocarditis, previous aortic surgery, or Marfan syndrome were excluded. All available follow-up imaging was reviewed.

RESULTS

Mean imaging follow-up was 5.5 (±5.3) years. Of all patients, 66.5% had at least 1 aortic root measurement after the index operation. Baseline aortic diameter was comparable between groups. In patients with BAV, aortic root diameter increased at a clinically negligible rate over time (0.654 mm per year; 95% confidence interval, 0.291-1.016; P < .001), similar to patients with TAV (P = .92). Mean clinical follow-up was 8.1 (±5.4) years. During follow-up, 18 patients underwent reoperation, 89% for a degenerated bioprosthetic aortic valve. Only 1 patient underwent reoperation for a primary indication of aortic aneurysmal disease, 22 years after the index operation. There were no differences in cumulative incidence rates of aortic reoperation (P = .14) between patients with BAV and TAV.

CONCLUSIONS

Mid-term imaging after aortic valve and ascending aorta replacement indicates that if the aortic root is not dilated at the time of surgery, the risk of enlargement over time is minimal, negating the need for prophylactic root replacement in patients with BAV or TAV.

Bicuspid aortic valve disease and ascending aortic aneurysm: should an aortic root replacement be mandatory?†

OBJECTIVES

The higher risk of adverse aortic events in patients with bicuspid aortic valve (BAV) disease and ascending aorta aneurysm is known, but the management of moderate aortic root dilatation in younger patients is a controversial issue. The aim of the study was to compare survival in patients with or without root replacement.

METHODS

We reviewed 166 consecutive patients with BAV disease and concomitant ascending aorta aneurysm (mean ascending aorta diameter: 51.4 ± 7.2 mm) undergoing cardiac surgery from 1994 to 2010. A total of 77 patients underwent Bentall procedure (90.9% male, mean age: 55.7 ± 12.7 years, Bentall group), whereas the remaining 89 patients underwent aortic valve replacement with supracoronary ascending aorta replacement (SAAR 71.9% male, mean age: 60.5 ± 11.2 years, SAAR group, P = 0.002). The preoperative mean diameter of the root was 44.0 ± 7.2 mm in the Bentall, and 38.5 ± 4.8 mm in the SAAR group (P < 0.0001).

RESULTS

In-hospital mortality was 2.6% in the Bentall, and 2.3% in the SAAR groups. Overall survival was 84 and 81% in the Bentall (median follow-up: 105 months) versus 89 and 88% in the SAAR (median follow-up: 73 months) groups at 10 and 15 years (P = 0.36), respectively. The mean cardiopulmonary bypass (CPB) time was 201 ± 56 min and 174 ± 58 min (P = 0.0016), the mean cross-clamp time 156 ± 42 min and 132 ± 38 min (P = 0.0008) in the Bentall and SAAR groups, respectively. Four sudden deaths have occurred in the Bentall group and in 2 in the SAAR group. Progressive dilatation of the aortic root in the SAAR group was not significat (postoperative mean diameter: 36.3 ± 4.4 mm). Neither subgroup of patients in the SAAR with preoperative moderate dilatation of aortic root had significat aortic dilatation at the mean follow-up of 73 ± 39 months (preoperative diameter: 43.5 ± 2.3 mm versus postoperative: 39.1 ± 4.2 mm). One patient in Bentall and 1 in the SAAR groups were reoperated for tubular graft infection.

CONCLUSIONS

In patients with BAV disease, ascending aorta aneurysm and moderate dilatation of the root, the significat reduction of CPB and cross-clamp times, the stability of the residual root at long term and the low risk of adverse aortic events associated with SAAR compared with the Bentall procedure have led us to consider the isolated aortic valve replacement with supracoronary aorta replacement an alternative strategy to the Bentall procedure, especially in high-risk and older patients.

Late outcome of noncoronary sinus replacement in patients with bicuspid aortic valves and aortopathy

BACKGROUND

Aortopathy associated with bicuspid aortic valve commonly involves the ascending aorta above the sinotubular ridge, but it may also affect sinus portions of the aorta. In some persons, the enlarged portion of the aortic root is limited to the noncoronary sinus. In such patients, we have spared the remaining portions of the aortic root by replacing the ascending aorta with a polyethylene terephthalate fiber (Dacron) graft and a tongue-shaped extension of the graft, thereby replacing the noncoronary sinus. In the present study, we evaluated late outcomes of this procedure, with specific attention to the fate of aortic tissue in the remaining sinuses.

METHODS

We reviewed the medical records of 1,756 patients with repair of ascending aortic aneurysms at Mayo Clinic from 1993 through 2012. Among the patients, 631 (35.9%) had bicuspid aortic valve, and in 79 (4.5%) of the patients, the noncoronary sinus was replaced along with the ascending aorta.

RESULTS

Associated aortic valve operations were performed in 70 patients; 15 had repair and 55 had aortic valve replacement. No early death occurred, but 3 patients died late after operation (5-year survival, 99%). There were 3 late reoperations, all because of native or prosthetic valve problems. Importantly, no instances occurred of aneurysm formation or aortic dissection related to the remaining aorta in the left and right aortic sinuses.

CONCLUSIONS

In patients with bicuspid aortic valve and aortic root enlargement related mainly to enlargement of the noncoronary sinus, limited replacement of the noncoronary sinus and ascending aorta is a safe and simple procedure that is durable in midterm follow-up.

Geometric orientation of the aortic neoroot in patients with raphed bicuspid aortic valve disease undergoing primary cusp repair and a root reimplantation procedure

OBJECTIVES

Primary cusp repair + aortic root reimplantation in bicuspid aortic valve (BAV) disease presenting with root aneurysm with aortic insufficiency (AI) is an effective surgical treatment. We assessed whether the geometric orientation of the repaired BAV into its reimplanted neoroot affects outcomes-180°/180° orientation was compared with the 150°/210° orientation.

METHODS

From 2005 to 2012, 66 BAV repairs were performed. This is a retrospective review of all types of Ib/II BAV AI patients undergoing root reimplantation (n = 26) at two different geometric orientations: 180°/180° (n = 11) vs 150°/210° (n = 15). In the 180°/180° group, reimplantation into the neoroot was such that both conjoint and non-conjoint cusps occupied 180° of the annular circumference. In the 150°/210° group, the repaired valve was configured to the more typical native orientation of a type I BAV: the non-conjoint cusp occupied 150°, and the conjoint cusp occupied 210° of the annular circumference.

RESULTS

Preoperative characteristics were similar in both groups. In-hospital mortality, stroke, reoperation, renal failure and pacemaker rates were zero in both groups. No patient left the operating room with >1+ AI and one had a peak gradient >20 mmHg. Transvalvular gradients were higher in the 180°/180° group, but not significant (P > 0.05). M.ean follow-ups for the 180°/180° and 150°/210° group were 48 and 33 months, respectively. Actuarial freedom from AI >2+ at 5 years was 100% in both groups. Freedom from AI >1+ at 5 years was 90 ± 10% in the 150°/210° group and 86 ± 13% in the 180°/180° group (P = 0.71). Freedom from peak gradient >20 mmHg was 80% (n = 8) in the 180°/180° group and 100% in the 150°/210° group at 1-year follow-up. Transvalvular gradients were higher in the 180°/180° group (16 ± 8 vs 10 ± 4 mmHg, P = 0.02; 9 ± 3 vs 5 ± 3 mmHg, P = 0.01). Five-year actuarial survival and freedom from aortic reoperation have remained at 100% in the entire cohort.

CONCLUSION

Cusp repair + root reimplantation for BAV type Ib/II AI can be safely performed at either geometric orientation. Conceptually, 150°/210° orientation respects the natural type I BAV anatomy with regard to cusp surface area and leaflet insertion perimeter. The 180°/180° group may have higher transvalvular gradients and smaller coaptation zones than the 150°/210° group. Further follow-up may reveal the superiority of one geometric orientation over the other.

Focus on the unique mechanisms involved in thoracic aortic aneurysm formation in bicuspid aortic valve versus tricuspid aortic valve patients: clinical implications of a pilot study

OBJECTIVES

The involvement of different factors in the onset of thoracic aortic aneurysm (TAA) in patients with a bicuspid aortic valve (BAV) vs those with a tricuspid aortic valve (TAV) is well recognized. However, the molecular, genetic and cellular mechanisms driving TAA remain unclear. The aim of this study was to identify the different mechanisms involved in TAA development in patients with BAV vs TAV.

METHODS

Aorta specimens and DNA samples were collected from 24 BAV (18 men and 6 women; mean age: 54.2 ± 14.39 years) and 110 TAV (79 men and 31 women, mean age: 66 ± 9.8 years) patients. A control group of 128 subjects (61 men and 67 woman, mean age: 61.1 ± 5.8 years) was also enrolled. Histopathological and immunohistochemical analyses were performed, as well as genotyping of 10 polymorphisms.

RESULTS

In BAV-associated ascending aortas, significant severe plurifocal apoptosis of smooth muscle cells and matrix metalloproteinase-9 (MMP-9) amounts were detected. In contrast, TAV-associated ascending aortas were characterized by a significant severity of elastic fragmentation, cystic medial necrosis, medial fibrosis and inflammation. In addition, in BAV cases, the -1562TMMP-9 and -735TMMP-2 alleles represent independent risk factors for TAA. The effects of these genotypes combined with hypertension and smoking in BAV cases result in an increase in both the apoptosis (P = 0.0001) and levels of MMP-9 (P = 0.001). In TAV cases, the D angiotensin-converting enzyme and +896A Toll-like receptor-4 alleles seem to be the predictive factors for TAA risk. They, combined with hypertension and age, significantly increase both the microscopic lesions and inflammation.

CONCLUSIONS

Our data seem to suggest that TAA in BAV and TAV patients arises from different molecular, cellular and genetic mechanisms. They might help to identify the potential molecular and genetic biomarkers that are useful to detect BAV subjects at high TAA risk, to monitor and treat them differently from those with TAV, with approaches such as the complete removal of the ascending aorta, including the aortic root with or without dilatation.

A shifting approach to management of the thoracic aorta in bicuspid aortic valve

OBJECTIVES

The scientific understanding of aortic dilation associated with bicuspid aortic valve (BAV) has evolved during the past 2 decades, along with improvements in diagnostic technology and surgical management. We aimed to evaluate secular trends and predictors of thoracic aortic surgery among patients with BAV in the United States.

METHODS

We used the 1998-2009 Nationwide Inpatient Sample, an administrative dataset representative of US hospital admissions, to identify hospitalizations for adults aged 18 years or more with BAV and aortic valve or thoracic aortic surgery. Covariates included age, gender, year, aortic dissection, endocarditis, thoracic aortic aneurysm, number of comorbidities, hospital teaching status and region, primary insurance, and concomitant coronary artery bypass surgery.

RESULTS

Between 1998 and 2009, 48,736 ± 3555 patients with BAV underwent aortic valve repair or replacement and 1679 ± 120 patients with BAV underwent isolated thoracic aortic surgery. The overall number of surgeries increased more than 3-fold, from 4556 ± 571 in 1998/1999 to 14,960 ± 2107 in 2008/2009 (P < .0001). The proportion of aortic valve repair or replacement including concomitant thoracic aortic surgery increased from 12.8% ± 1.4% in 1998/1999 to 28.5% ± 1.6% in 2008/2009, which mirrored an increasing proportion of patients with a diagnosis of thoracic aortic aneurysm. Mortality was equivalent for patients undergoing aortic valve repair or replacement with thoracic aortic surgery and those undergoing isolated aortic valve repair or replacement (1.8% ± 0.3% vs 1.5% ± 0.2%; multivariable odds ratio, 1.02; 95% confidence interval, 0.67-1.57), with decreasing mortality over the study period (from 2.5% ± 0.6% in 1998/1999 to 1.5% ± 0.2% in 2008/2009; multivariable odds ratio per 2-year increment, 0.89; 95% confidence interval, 0.81-0.99; P = .03). Total charges for BAV surgical hospitalizations increased more than 7.5-fold from approximately $156 million in 1998 to $1.2 billion in 2009 (inflation-adjusted 2009 dollars).

CONCLUSIONS

There was a marked increase in the use of thoracic aortic surgery among patients with BAV.