Calcification and atheroma plaques: is there any impact on the anatomical features of the aortic root and its elements?

OBJECTIVES

Morphometric information of the structures within the borders of the aortic root is a guide for surgical interventions. It is essential to determine the effects of aortic calcification and atheroma plaque findings on the structures of this region. This study aims to establish the normal values of aortic root structures and to investigate the impact of pathologic findings in order to guide diagnosis and treatment in the clinic.

METHODS

The aortic root structures were morphometrically analyzed in fresh hearts of 110 patients (89 males, 21 females) brought to the forensic medicine institution. The distances between the bases of the aortic sinuses, their widths and heights, and the lengths of the commissures were measured to differentiate between pathologic and non-pathologic aortic classes. Parameters were compared according to gender, age, body mass index, and body surface area.

RESULTS

The mean age was 44.71 ± 15.57 years in 21 female patients and 53.66 ± 15.67 years in 89 male patients. The results of the pathologic aorta group with calcification and atheroma plaque findings were higher than the non-pathologic aorta group in all parameters (P < .05).

CONCLUSIONS

Calcification and the presence of atheroma plaque in the aorta increase the size of the structures at the aortic root. Gender, age, body mass index, and body surface area are among the criteria that will cause changes in the structures of this region. These results will help surgeons to know the normal values of aortic root structures and to consider the effects of pathologic findings in aortic valve repair operations.

Pigs as Models to Test Cardiovascular Devices

Pigs as laboratory animals are used in preclinical studies aimed at developing medical devices for cardiac surgery. The anatomy of the cardiovascular system of these animals has been well studied and acknowledged as suitable for use and the testing of new cardiovascular devices developed for humans. However, there are no morphometric characteristics of the aortic root and thoraco-abdominal part of porcine aorta. This can lead to difficulties in experimental surgery and even result in the death of experimental animals due to the mismatch in the size of the implantable devices. Thus, such information is essential to enhance the efficiency of surgical technologies used for eliminating aortic pathologies in their various sections. The purpose of our research is to study the anatomy of the aorta in mini pigs and to assess whether the size, age, and sex of the animals affect the size of the main structures in their aortas. In addition, we attempted to compare the results obtained by transesophageal echocardiography (TEE) and angiography. We studied 28 laboratory mini pigs, dividing them into three groups by body weight (40-70 kg, 71-90 kg, and 90 kg). We did not find any relationship between the external somatometric characteristics of the animals and the size of their aortas. Animals have individual anatomical variability in their cardiovascular systems, which means that they need to be examined in terms of preoperative planning by any available method-echocardiography, angiography, or multispiral computed tomography (CT).

Ozaki procedure-re-construction of aortic valve leaflets using autologous pericardial tissue: a review

The Ozaki procedure has emerged as a valuable option for treating various aortic valve pathologies. This review article delves into the intricacies of this innovative surgical approach by exploring its adaptation to the complex anatomy and physiology of the aortic root. The diverse etiologies of aortic valve diseases, ranging from congenital anomalies to degenerative changes, make treatment selection a complex challenge. Aortic valve replacement has traditionally been the gold standard, but emerging evidence supports valve repair techniques, emphasizing the importance of preserving native tissue. Nevertheless, issues like lifelong anticoagulation with mechanical valves and patient-prosthetic mismatch remain. The Ozaki procedure offers a compelling alternative by utilizing autologous pericardium or a tissue substitute to construct new aortic valve leaflets. This technique, standardized by Dr. Ozaki in 2007, provides a customizable and adaptable solution. The article highlights the anatomy of the aortic root, emphasizing the critical role of the sinus of Valsalva and interleaflet triangles in maintaining proper valve function. The procedure's unique adaptation to aortic root dynamics allows for reduced mechanical stress during systole and diastole, mimicking the natural valve's behavior. Furthermore, Ozaki leaflets exhibit promising hemodynamics and reduced risks of complications, such as permanent pacemaker implantation and patient-prosthetic mismatch. The use of autologous pericardium in the Ozaki procedure presents advantages, including enhanced tissue strength, minimal immunogenicity, and reduced risk of immune-mediated calcification. These factors contribute to the longevity and resilience of the reconstructed valve. This comprehensive review aims to shed light on the procedure's intricacies, its alignment with aortic root anatomy and physiology, and its potential as a valuable tool in the armamentarium of aortic surgeons.

Determination of Optimal Fluoroscopic Angulations for Left Main Coronary Artery Ostial Interventions: 3-Dimensional Computed Tomography Validation

Background. Current recommendations for the best views for the left main coronary artery (LMCA) ostium intervention are empirical. Objectives. To determine the optimal projection to visualize the LMCA ostium using only fluoroscopy. Methods. The optimal projection to visualize the LMCA ostium was determined using fluoroscopic images of superimposing the lowest points of the distal ends of two J tipped wires in the noncoronary cusp (NCC) and right coronary cusp (RCC). This was validated independently using 3-dimensional computed tomography (3D-CT) reconstruction. Results. Satisfactory images of the overlapping wires in NCC and RCC could be obtained in 90% (45/50). Between the fluoroscopic and the 3D-CT reconstruction approaches, the mean difference for NCC and RCC overlapping at horizontal axes is -1.8 with a 95% limit of agreement between −3.94 and 0.34 $\left(p=0.10\right)$ and at vertical axes −1.6 with a 95% limit of agreement between −3.46 and 0.26 $\left(p=0.09\right)$ ; and the mean difference for the optimal projection to visualize the LMCA ostium at horizontal axes is −3.22 with a 95% limit of agreement between -7.26 and 0.81 $\left(p=0.11\right)$ and at vertical axes −2.31 with a 95% limit of agreement between −5.83 and 1.21 $\left(p=0.09\right)$ . The 3D angulation deviation for the optimal projection to visualize the LMCA ostium was 8.5° ± 4.7° when the LMCA ostium faced the NCC-RCC commissure (n = 32) and 22.3° ± 16.0° $\left(p=0.009\right)$ when it did not (n = 13). Conclusions. The optimal projection for LMCA ostial intervention can be determined using fluoroscopic images of superimposing wires in the NCC and RCC when the LMCA ostium faces the NCC-RCC commissure, as was the case in 71% of the patients studied.

Understanding the Aortic Root Using Computed Tomographic Assessment: A Potential Pathway to Improved Customized Surgical Repair

There is continued interest in surgical repair of both the congenitally malformed aortic valve, and the valve with acquired dysfunction. Aortic valvar repair based on a geometric approach has demonstrated improved durability and outcomes. Such an approach requires a thorough comprehension of the complex 3-dimensional anatomy of both the normal and congenitally malformed aortic root. In this review, we provide an understanding of this anatomy based on the features that can accurately be revealed by contrast-enhanced computed tomographic imaging. We highlight the complimentary role that such imaging, with multiplanar reformatting and 3-dimensional reconstructions, can play in selection of patients, and subsequent presurgical planning for valvar repair. The technique compliments other established techniques for perioperative imaging, with echocardiography maintaining its central role in assessment, and enhances direct surgical evaluation. This additive morphological and functional information holds the potential for improving selection of patients, surgical planning, subsequent surgical repair, and hopefully the subsequent outcomes.

Role of the Transient Receptor Potential Vanilloid Type 1 (TRPV1) in the Regulation of Nitric Oxide Release in Wistar Rat Aorta

The potential transient vanilloid receptor type 1 (TRPV1) plays important functional roles in the vascular system. In the present study, we explored the role of the TRPV1 in the production of nitric oxide (NO), biopterines (BH4 and BH2), cyclic guanosine monophosphate (cGMP), malondialdehyde (MDA), phosphodiesterase-3 (PDE-3), total antioxidant capacity (TAC), and calcitonin gene-related peptide (CGRP) in the rat aorta. Wistar rats were divided into four groups: (1) control, (2) capsaicin (CS, 20 mg/kg), (3) capsazepine (CZ, 24 mg/kg), and (4) CZ + CS. Treatments were applied daily for 4 days before removing the thoracic aortas for testing of aortic tissue and endothelial cells. TRPV1 activation produced increases in BH4 14%, cGMP 25%, NO 29%, and TAC 59.2% in comparison to the controls. BH2 and MDA increased with CZ. CGRP shows a tendency to decrease with CZ. The analysis by immunocytochemistry confirmed that the TRPV1 is present in aortic endothelial cells. Aortic endothelial cells were obtained from healthy rats and cultured to directly explore the effects of CS and CZ. The activation of the TRPV1 (CS 30 μM) produced increases in BH4 17%, NO 36.6%, TAC 56.3%, and CGRP 65%, when compared to controls. BH2 decreased with CZ + CS. CS effects were diminished by CZ in cells and in the tissue. We conclude that the TRPV1 is a structure present in the membrane of aortic endothelial cells and that it participates in the production of NO. The importance of the TRPV1 should be considered in vascular reactivity studies.

A virtual-reality imaging analysis of the dynamic aortic root anatomy

PURPOSE

To measure and explore complex cardiac anatomy in research and preoperative simulation, a virtual imaging technology, the Vesalius 3D suite, combines Vesalius 3D three-dimensional (3D) image-processing software with an optic-tracking navigation system running PST-Client software. We present a novel method of evaluating dynamic aortic root geometry in vivo using this visualization system.

DESCRIPTION

Based on electrocardiography-gated cardiac computed tomography data in systole and diastole, images of the aortic root in a normal healthy adult were reconstructed for 3D visualization. Virtual interaction tools were used to explore and measure the aortic root structures.

EVALUATION

Virtually reconstructed images revealed the aortic root internal structures in exquisite detail. Highly accessible 3D interpretation promptly permitted precise measurements of repair-relevant anatomical parameters including geometrically complex curves of the aortic root wall and dynamic changes in the aortic valves. Measurement accuracy examined against a known prosthesis showed within 1mm of error (< 0.5%).

CONCLUSION

This technology may promote understanding of aortic root form and function, and facilitate valve-sparing surgery, and seems valuable for 3D exploration-and-measurement of cardiac anatomy in vivo.

Systolic stretching of the ascending aorta

INTRODUCTION

Longitudinal stretching of the aorta due to systolic heart motion contributes to the stress in the wall of the ascending aorta. The objective of this study was to assess longitudinal systolic stretching of the aorta and its correlation with the diameters of the ascending aorta and the aortic root.

MATERIAL AND METHODS

Aortographies of 122 patients were analyzed. The longitudinal systolic stretching of the aorta caused by the contraction of the heart during systole and the maximum dimensions of the aortic root and ascending aorta were measured in all patients.

RESULTS

The maximum dimension of the aortic root was on average 34.9 ±4.5 mm and the mean diameter of the ascending aorta was 33.9 ±5.4 mm. The systolic aortic stretching negatively correlated with age (r = -0.49, p < 0.001) and the diameter of the tubular ascending aorta (r = -0.44, p < 0.001). There was no significant correlation between the stretching and the dimension of the aortic root (r = -0.11, p = 0.239). There was a statistically significant (p < 0.001) difference in the longitudinal aortic stretching values between patients with a normal aortic valve (10.6 ±3.1 mm) and an aortic valve pathology (8.0 ±3.2 mm in all patients with an aortic valve pathology; 7.5 ±4.3 mm in isolated aortic stenosis, 8.5 ±2.9 mm in the case of isolated insufficiency, 8.2 ±2.8 mm for valves that were both stenotic and insufficient).

CONCLUSIONS

Systolic aortic stretching negatively correlates with the diameter of the tubular ascending aorta and the age of the patients, and does not correlate with the diameter of the aortic root. It is lower in patients with an aortic valve pathology.

The aortic root hexagon as an aide memoire to the important surgical landmarks

BACKGROUND

The anatomy of the aortic root and its relationship to cardiac landmarks is important for valve-sparing surgery and understanding the pathology of lesions arising in this structure. Rapid understanding of the key anatomical details can be achieved by a geometrical concept based on the shape of a hexagon.

METHODS

Definitions, structure, and key anatomical concepts of the aortic root according to the current literature were reviewed. Thirty pig hearts were dissected to explore the relationships of the six points on the aortic root. Six double 2/0 ethibond needles were placed into the six points at 90°. The passage of the needles through the specific cardiac landmarks at each point was noted. The aortic root hexagon is a geometrical structure formed by two triangles superimposed on each other. The six points in the hexagon relate to important adjacent cardiac landmarks.

RESULTS

The two best-known anatomical relationships are of the left-non coronary aortic commissure to the longitudinal axis of symmetry of the aortic leaflet of the mitral valve and the relationship of the nadir of the noncoronary aortic valve leaflet to the medial commissure of the mitral valve. The other four points are related to equally significant and well defined anatomical landmarks.

CONCLUSION

The aortic root hexagon is made by two triangles superimposed on each other, these are the commissural and nadir triangles respectively. We have found this concept to be a quick way to learn and remember the key anatomical relationships of the aortic root.

Anatomy of the aortic root: implications for aortic root reconstruction

Since the introduction of valve-preserving root replacement and aortic annuloplasty, precise understanding of the aortic root anatomy has emerged as a key to successful aortic valve-preservation surgery. Fundamentally, surgeons need to know the precise anatomical definition and structure of the aortic root, including its normal dimensions, know the anatomy of the coronary arteries, and understand the cardiac conduction system. Surgeons must be able to clearly distinguish normal and abnormal structures, and recognize the effects of aortic valve regurgitation or root expansion on dimensions and geometric relationships within the aortic root. Possessing a detailed understanding of the aortic root, surgeons can select appropriately sized grafts and achieve optimum annular fixation. This review covers the essentials of aortic root anatomy and provides tips for correct and safe performance of aortic valve-preservation surgery with a view toward durable late outcomes.

When and How to Enlarge the Small Aortic Root

Successful enlargement of the small aortic root in children has remained a management challenge, particularly in the neonates and small infants. Achieving this aim requires thorough understanding of the anatomic features of the left ventricular outflow tract, careful patient selection, and skilful execution of complex surgery. This article reviews the anatomical principles upon which the surgical techniques rely, the decision-making, the timing of surgery, the surgical options, and the outcomes.

Anatomical Factors Influencing Selective Vestibular Neurectomy: A Comparison of Posterior Fossa Approaches

Objectives To identify measurable anatomical factors that may guide the surgical approach for posterior fossa selective vestibular neurectomy (SVN) and predict identification of the vestibulocochlear cleavage (VCC) plane. Study Design Dissection of fixed cadaveric heads through retrolabyrinthine and retrosigmoid-internal auditory canal (RSG-IAC) approaches with measurement of landmarks. Setting Cadaveric dissection model. Main Outcome Measures Area of the Trautmann triangle (TT) and the distance from the posterior semicircular canal to the anterior border of the sigmoid along the posterior Donaldson line (pDL). VCC planes from each approach were calculated and compared. Results Overall mean pDL was 8.53 mm (range: 5-11.5 mm); mean TT area was 124 mm(2) (range: 95-237 mm(2)). The VCC was identified in 63% of ears through the retrolabyrinthine (RVN) approach alone, whereas 37% of ears required the RSG-IAC approach. In ears requiring IAC dissection, the VCC was found within 1 to 2 mm distal to the porus. The pDL (p < 0.05) and area of TT (p < 0.05) were significantly larger in the RVN group compared with the RSG-IAC group. Conclusion Ears amenable to the RVN approach had a greater pDL and TT area. These anatomical measurements may have a role in surgical planning and the choice of approach for SVN.