Anesthetic management for cesarean section in two parturient with ascending aortic aneurysm: a case-based discussion

BACKGROUND

The anesthetic management of parturients with ascending aortic aneurysm for cesarean section can be particularly challenging, primarily because of increased risk for aortic dissection or aneurysm rupture.

CASE PRESENTATION

We present some aspects of the anesthetic management of two parturients with ascending aortic aneurysm for cesarean sections; amongst, the use of remifentanil with its effects on patient and newborn. We emphasize the importance of a cardio-obstetric team in the context of preoperative planning of such patients. Also, we reviewed some literature on the anesthetic management with its effect on peri-operative hemodynamic stability.

CONCLUSION

Maintaining hemodynamic stability is paramount in the prevention of the rupture or dissection of ascending aortic aneurysm during labor of parturient.

Unicommissural unicuspid aortic valve (UAV) presenting as ascending aortic aneurysm with aortic dissection

We herein present an exceptionally rare instance of a unicommissural unicuspid aortic valve (UAV) manifesting with an aneurysmal ascending aorta complicated by a type A aortic dissection .

Flow patterns in ascending aortic aneurysms: Determining the role of hypertension using phase contrast magnetic resonance and computational fluid dynamics

Thoracic aortic aneurysm (TAA) is a local dilation of the thoracic aorta. Although universally used, aneurysm diameter alone is a poor predictor of major complications such as rupture. There is a need for better biomarkers for risk assessment that also reflect the aberrant flow patterns found in TAAs. Furthermore, hypertension is often present in TAA patients and may play a role in progression of aneurysm. The exact relation between TAAs and hypertension is poorly understood. This study aims to create a numerical model of hypertension in the aorta by using computational fluid dynamics. First, a normotensive state was simulated in which flow and resistance were kept unaltered. Second, a hypertensive state was modeled in which blood inflow was increased by 30%. Third, a hypertensive state was modeled in which the proximal and peripheral resistances and capacitance parameters from the three-element Windkessel boundary condition were adjusted to mimic an increase in resistance of the rest of the cardiovascular system. One patient with degenerative TAA and one healthy control were successfully simulated at hypertensive states and were extensively analyzed. Furthermore, three additional TAA patients and controls were simulated to validate our method. Hemodynamic variables such as wall shear stress, oscillatory shear index, endothelial cell activation potential (ECAP), vorticity and helicity were studied to gain more insight on the effects of hypertension on flow patterns in TAAs. By comparing a TAA patient and a control at normotensive state at peak-systole, helicity and vorticity were found to be lower in the TAA patient throughout the entire domain. No major changes in flow and flow derived quantities were observed for the TAA patient and control when resistance was increased. When flow rate was increased, regions with high ECAP values were found to reduce in TAA patients in the aneurysm region which could reduce the risk of thrombogenesis. Thus, it may be important to assess cardiac output in patients with TAA.

Coarctation of Aorta With Tricuspid Aortic Valve Is Not Associated With Ascending Aortic Aneurysm

BACKGROUND

Aortic aneurysm is common in patients with coarctation of aorta (COA), but it is unclear whether the risk of aortic aneurysms is due to COA or related to the presence of other risk factors such as bicuspid aortic valve (BAV) and hypertension.

OBJECTIVES

The purpose of this study was to assess the relationship among COA, BAV, and thoracic aortic aneurysms.

METHODS

A total of 867 patients with COA (COA group) were matched 1:1:1 to 867 patients with isolated BAV (BAV group) and 867 patients without structural heart disease (SHD) (no-SHD group). The COA group was further subdivided into a COA+BAV subgroup (n = 304 [35%]), and COA with tricuspid aortic valve (TAV) (COA+TAV subgroup [n = 563 (65%)]). Aortic dimensions were assessed at baseline and at 3, 5, and 7 years.

RESULTS

Compared with the no-SHD group, the COA+BAV subgroup had larger aortic root diameter (37 mm [Q1-Q3: 30-43 mm] vs 32 mm [Q1-Q3: 27-35 mm]; P < 0.001) and mid ascending aorta dimeter (34 mm [Q1-Q3: 29-40 mm] vs 28 mm [Q1-Q3: 24-31 mm]; P = 0.008). Similarly, the BAV group had larger aortic root diameter (37 mm [Q1-Q3: 30-42 mm] vs 32 mm [Q1-Q3: 27-35 mm]; P < 0.001), and mid ascending aorta dimeter (35 mm [Q1-Q3: 30-40 mm] vs 28 mm [Q1-Q3: 24-31 mm]; P < 0.001). Compared with the COA+TAV subgroup, the COA+BAV subgroup and BAV group were associated with larger aortic root and mid ascending aorta diameter at baseline and follow-up. The risk of acute aortic complications was low in all groups.

CONCLUSIONS

These findings suggest that BAV (and not COA) was associated with ascending thoracic aorta dimensions, and that patients with COA+TAV were not at a greater risk of developing ascending aortic aneurysms as compared with patients without SHD.

Takayasu's Arteritis: A Special Case Report and Review of the Literature

Background: Takayasu's arteritis is a rare type of vasculitis with severe complications like stroke, ischemic heart disease, pulmonary hypertension, secondary hypertension, and aneurysms. Diagnosis is achieved using clinical and angiographic criteria. Treatment is medical and surgical, but unfortunately, the outcome is limited. Case presentation: A 34-year-old Caucasian woman had an ischemic stroke (2009). She was diagnosed with Takayasu's arteritis and received treatment with methotrexate, prednisolone, and antiplatelet agents, with a mild improvement in clinical state. After 6 years (2015), she experienced an ascending aorta aneurysm, pulmonary hypertension, and mild aortic regurgitation. Surgical treatment solved both the ascending aorta aneurysm and left carotid artery stenosis (ultrasound in 2009 and computed tomography angiogram in 2014). Morphopathology revealed a typical case of Takayasu's arteritis. Tumor necrosis factor inhibitors (TNF inhibitors) were prescribed with methotrexate. At 48 years old (2023), she developed coronary heart disease (angina, electrocardiogram); echocardiography revealed severe pulmonary hypertension, and angiography revealed normal coronary arteries, abdominal aorta pseudoaneurysm, and arterial-venous fistula originating in the right coronary artery with drainage in the medium pulmonary artery. The patient refused surgical/interventional treatment. She again received TNF inhibitors, methotrexate, antiplatelet agents, and statins. Conclusions: This case report presented a severe form of Takayasu's arteritis. Our patient had multiple arterial complications, as previously mentioned. She received immunosuppressive treatment, medication targeted to coronary heart disease, and surgical therapy.

Surgery for Ascending Aortic Aneurysm and Aortic Valve Insufficiency in Conditions of Active Proceeding Syphilitic Aortitis and Valvulitis

A syphilitic aortitis is a late cardiovascular lesion of tertiary syphilis that has become exceptionally rare in the antibiotic era but not eradicated completely. Syphilitic aortitis of ascending aorta complicates in ascending aortic aneurysm formation and aortic valve regurgitation, both requiring surgical treatment. After surgery, lifelong surveillance of the remainder of the aorta is recommended because of a priori supposed high incidence of delayed involvement of noninvolved aortic segments. A 3-year follow-up result of surgery of syphilitic ascending aortic aneurysm with aortic valve regurgitation in condition of active ongoing syphilitic aortitis and valvulitis is described with addressing the dimensions of remaining aortic segments. This case demonstrates that the dilatation of the remainder of the aorta does not occur during 3 years, at least when anti-syphilitic course of antibiotic is used just after operation without additional treatment during the follow-up period. A few reports on surgical treatment of syphilitic aneurysms of the ascending aorta are discussed.

Ventricular septal defect associated with aortic regurgitation and ascending aortic aneurysm: a case report

INTRODUCTION

Ventricular septal defect (VSD) is one of the most common congenital cardiac anomalies. Patients with perimembranous VSD may have aortic regurgitation (AR) secondary to prolapse of the aortic cusp.

CASE PRESENTATION

We present a case of 23-year-old White man with VSD, AR and ascending aortic aneurysm. The patient presented to outpatient clinic with weakness and gradual worsening shortness of breath for the past 5 years. Clinical examination revealed regular heart rhythm and loud continuous systolic-diastolic murmur (Lewin's grade 6/6), heard all over the precordium, associated with a palpable thrill. The ECG showed right axis deviation, fractionated QRS in V1 and signs of biventricular hypertrophy. The chest X-ray showed cardiomegaly. Transthoracic and transesophageal echocardiograms showed a perimembranous VSD with moderate restrictive shunt (Qp/Qs = 1.6), aortic regurgitation (AR), and ascending aortic aneurysm. Other clinical and laboratory findings were within normal limits.

CONCLUSIONS

Perimembranous VSD, may be associated with aortic regurgitation and ascending aortic aneurysm as secondary phenomenon if it is not early diagnosed and successfully treated.

Ascending aortic aneurysm and histopathology in Alport syndrome: a case report

BACKGROUND

Alport syndrome (AS) is caused by mutations in type IV collagen genes that typically target and compromise the integrity of basement membranes in kidney, ocular, and sensorineural cochlear tissues. Type IV and V collagens are also integral components of arterial walls, and whereas collagenopathies including AS are implicated in aortic disease, the incidence of aortic aneurysm in AS is unknown probably because of underreporting. Consequently, AS is not presently considered an independent risk factor for aortic aneurysm and more detailed case studies including histological evidence of basement membrane abnormalities are needed to determine such a possible linkage.

CASE PRESENTATION

Here, we present unique histopathological findings of an ascending aortic aneurysm collected at the time of surgery from an AS patient wherein hypertension was the only other known risk factor.

CONCLUSIONS

The studies reveal classical histological features of aortic aneurysm, including atheroma, lymphocytic infiltration, elastin disruption, and myxoid degeneration with probable AS association.

Regional biomechanical characterization of human ascending aortic aneurysms: Microstructure and biaxial mechanical response

The ascending thoracic aortic aneurysm (ATAA) is a permanent dilatation of the vessel with a high risk of adverse events, and shows heterogeneous properties. To investigate regional differences in the biomechanical properties of ATAAs, tissue samples were collected from 10 patients with tricuspid aortic valve phenotype and specimens from minor, anterior, major, and posterior regions were subjected to multi-ratio planar biaxial extension tests and second-harmonic generation (SHG) imaging. Using the data, parameters of a microstructure-motivated constitutive model were obtained considering fiber dispersion. SHG imaging showed disruptions in the organization of the layers. Structural and material parameters did not differ significantly between regions. The non-symmetric fiber dispersion model proposed by Holzapfel et al. [25] was used to fit the data. The mean angle of collagen fibers was negatively correlated between minor and anterior regions, and the parameter associated with collagen fiber stiffness was positively correlated between minor and major regions. Furthermore, correlations were found between the stiffness of the ground matrix and the mean fiber angle, and between the parameter associated with the collagen fiber stiffness and the out-of-plane dispersion parameter in the posterior and minor regions, respectively. The experimental data collected in this study contribute to the biomechanical data available in the literature on human ATAAs. Region-specific parameters for the constitutive models are fundamental to improve the current risk stratification strategies, which are mainly based on aortic size. Such investigations can facilitate the development of more advanced finite element models capable of capturing the regional heterogeneity of pathological tissues. STATEMENT OF SIGNIFICANCE: Tissue samples of human ascending thoracic aortic aneurysms (ATAA) were collected. Samples from four regions underwent multi-ratio planar biaxial extension tests and second-harmonic generation imaging. Region-specific parameters of a microstructure-motivated model considering fiber dispersion were obtained. Structural and material parameters did not differ significantly between regions, however, the mean fiber angle was negatively correlated between minor and anterior regions, and the parameter associated with collagen fiber stiffness was positively correlated between minor and major regions. Furthermore, correlations were found between the stiffness of the ground matrix and the mean fiber angle, and between the parameter associated with the collagen fiber stiffness and the out-of-plane dispersion parameter in the posterior and minor regions, respectively. This study provides a unique set of mechanical and structural data, supporting the microstructural influence on the tissue response. It may facilitate the development of better finite element models capable of capturing the regional tissue heterogeneity.

Computer-aided shape features extraction and regression models for predicting the ascending aortic aneurysm growth rate

OBJECTIVE

ascending aortic aneurysm growth prediction is still challenging in clinics. In this study, we evaluate and compare the ability of local and global shape features to predict the ascending aortic aneurysm growth.

MATERIAL AND METHODS

70 patients with aneurysm, for which two 3D acquisitions were available, are included. Following segmentation, three local shape features are computed: (1) the ratio between maximum diameter and length of the ascending aorta centerline, (2) the ratio between the length of external and internal lines on the ascending aorta and (3) the tortuosity of the ascending tract. By exploiting longitudinal data, the aneurysm growth rate is derived. Using radial basis function mesh morphing, iso-topological surface meshes are created. Statistical shape analysis is performed through unsupervised principal component analysis (PCA) and supervised partial least squares (PLS). Two types of global shape features are identified: three PCA-derived and three PLS-based shape modes. Three regression models are set for growth prediction: two based on gaussian support vector machine using local and PCA-derived global shape features; the third is a PLS linear regression model based on the related global shape features. The prediction results are assessed and the aortic shapes most prone to growth are identified.

RESULTS

the prediction root mean square error from leave-one-out cross-validation is: 0.112 mm/month, 0.083 mm/month and 0.066 mm/month for local, PCA-based and PLS-derived shape features, respectively. Aneurysms close to the root with a large initial diameter report faster growth.

CONCLUSION

global shape features might provide an important contribution for predicting the aneurysm growth.

Geometry and flow in ascending aortic aneurysms are influenced by left ventricular outflow tract orientation: Detecting increased wall shear stress on the outer curve of proximal aortic aneurysms

BACKGROUND

The geometrical characterization of ascending thoracic aortic aneurysms in clinical practice is limited to diameter measurements. Despite growing interest in hemodynamic assessment, its relationship with ascending thoracic aortic aneurysm pathogenesis is poorly understood. This study examines the relationship between geometry of the ventriculo-aortic junction and blood flow patterns in ascending thoracic aortic aneurysm disease.

METHODS

Thirty-three patients with ascending thoracic aortic aneurysms (exclusions: bicuspid aortic valves, connective tissue disease) underwent 4-dimensional flow magnetic resonance imaging. After image segmentation, geometrical parameters were measured, including aortic curvature, tortuosity, length, and diameter. A unique angular measurement made by the trajectory of the left ventricular outflow tract axis and the proximal aorta was also conducted. Velocity profiles were quantitatively and qualitatively analyzed. In addition, 11 patients (33%) underwent wall shear stress mapping of the ascending thoracic aortic aneurysm region using computational fluid dynamics simulation.

RESULTS

Greater left ventricular outflow tract aortic angles were associated with larger aortic diameters at the levels of the sinus (coefficient = 0.387, P = .014) and ascending aorta (coefficient = 0.284, P = .031). Patients with left ventricular outflow tract aortic angles greater than 60° had marked asymmetric flow acceleration on the outer curvature in the proximal aorta, ascertained from 4-dimensional flow analysis. For patients undergoing computational fluid dynamics assessment, regression analysis found that higher left ventricular outflow tract aortic angles were associated with significantly higher wall shear stress values in the outer curve of the aorta (coefficient 0.07, 95% confidence interval 0.04-0.11, P = .002): Angles greater than 50° yielded time-averaged wall shear stress values greater than 2.5 Pa, exhibiting a linear relationship.

CONCLUSIONS

Our findings strengthen the hypothesis of flow-mediated ascending thoracic aortic aneurysm disease progression and that left ventricular outflow tract aortic angle may be a predictor of disease severity.

Surgical Repair of Giant Asymptomatic Ascending Aortic Aneurysm Accompanied with Chronic Stanford Type A Aortic Dissection: A Case Report

Background: Ascending aortic aneurysm accompanied with stanford type A aortic dissection is a life-threatening condition. The most common presenting symptom is pain. Here, we report a very rare case of giant asymptomatic ascending aortic aneurysm accompanied with chronic stanford type A aortic dissection. Case presentation: A 72-year-old woman was founded to have ascending aortic dilation on a routine physical examination. On admission, CTA showed an ascending aortic aneurysm accompanied with stanford type A aortic dissection, the diameter of which was approximately 10 cm. Transthoracic echocardiography showed an ascending aortic aneurysm, aortic sinus and sinus junction dilation, moderate aortic valve regurgitation, left ventricle enlargement, left ventricular wall hypertrophy, and mitral and tricuspid valve mild regurgitation. The patient underwent surgical repair in our department, was discharged, and recovered well. Conclusion: This was a very rare case of a giant asymptomatic ascending aortic aneurysm accompanied with chronic stanford type A aortic dissection that was successfully managed by total aortic arch replacement.

Knowledge, attitudes, and practice preferences in the surgical threshold for ascending aortic aneurysm among Canadian cardiac surgeons

OBJECTIVE

The survey aimed to assess the practice patterns of Canadian cardiac surgeons on the size threshold at which patients with ascending aortic aneurysm would be offered surgery.

METHODS

A 18-question electronic survey was electronically distributed to 148 practicing cardiac surgeons in Canada via email from January to August 2020. Questions presented clinical scenarios focusing on modifying a single variable, and respondents were asked to identify their surgical size threshold for each of the clinical scenarios.

RESULTS

The individual response rate was 62.0% (91/148) and institutional response rate was 89.3% (25/29). For an incidental asymptomatic ascending aortic aneurysm in a 60-year-old otherwise-healthy male patient with a tricuspid aortic valve and bicuspid aortic valve of 1.9 m², 20.2% of the respondents would recommend surgery when the aneurysm was <5.5 cm. A significant number of surgeons modified their surgical threshold in response to changes to BSA, bicuspid aortic valve, growth rate, age, occupation, symptom, and family history (P < .01). Notably, if the patient had a bicuspid aortic valve, 41.0% of respondents lowered their threshold for surgery, with only 43.0% recommending surgery at ≥5.5 cm (P < .01).

CONCLUSIONS

Practice variations exist in the current size threshold for surgery of ascending aortic aneurysms in Canada. These differences between surgeons are further accentuated in the context of bicuspid aortic valve, smaller body stature, younger age, low growth rate, family history, and for the performance of isometric exercise. These represent important areas where future prospective studies are required to inform best practice.

Phospholipase Cε insufficiency causes ascending aortic aneurysm and dissection

Phospholipase Cε (PLCε) is a phospholipase C isoform with a wide range of physiological functions. It has been implicated in aortic valve disorders, but its role in frequently associated aortic disease remains unclear. To determine the role of PLCε in thoracic aortic aneurysm and dissection (TAAD) we used PLCε-deficient mice, which develop aortic valve insufficiency and exhibit aortic dilation of the ascending thoracic aorta and arch without histopathological evidence of injury. Fourteen days of infusion of Plce1+/+ and Plce1-/- mice with angiotensin II (ANG II), which induces aortic dilation and dissection, led to sudden death secondary to ascending aortic dissection in 43% of Plce1-/- versus 5% of Plce1+/+ mice (P < 0.05). Medial degeneration and TAAD were detected in 80% of Plce1-/- compared with 10% of Plce1+/+ mice (P < 0.05) after 4 days of ANG II. Treatment with ANG II markedly increased PLCε expression within the ascending aortic adventitia. Total RNA sequencing demonstrated marked upregulation of inflammatory and fibrotic pathways mediated by interleukin-1β, interleukin-6, and tumor necrosis factor-α. In silico analysis of whole exome sequences of 258 patients with type A dissection identified 5 patients with nonsynonymous PLCE1 variants. Our data suggest that PLCε deficiency plays a role in the development of TAAD and aortic insufficiency.NEW & NOTEWORTHY We describe a novel phenotype by which PLCε deficiency predisposes to aortic valve insufficiency and ascending aortic aneurysm, dissection, and sudden death in the setting of ANG II-mediated hypertension. We demonstrate PLCE1 variants in patients with type A aortic dissection and aortic insufficiency, suggesting that PLCE1 may also play a role in human aortic disease. This finding is of very high significance because it has not been previously demonstrated that PLCε directly mediates aortic dissection.