Aortic root remodeling in atheromatous aneurysms: the role of selected sinus repair

Reconstruction of aortic sinus using patches in patients with acute type A aortic dissection

OBJECTIVES

Acute type A aortic dissection involving the aortic sinus is often combined with varying degrees of aortic regurgitation, while the structure of the aortic valve is often undamaged. The aim of this study was to evaluate the clinical effects of reconstruction of the aortic sinus using patches in patients with acute type A aortic dissection.

METHODS

From January 2016 to December 2019, 52 patients with acute type A aortic dissection involving the aortic sinus were treated with aortic sinus reconstruction using pericardial or artificial vascular patches. The clinical and follow-up data were summarized.

RESULTS

Bovine pericardial patches were used in 31 cases and artificial vascular patches were used in 21 cases for aortic sinus reconstruction. Cardiopulmonary bypass time was (250.4 ± 65.7) min, aortic cross clamp time was (143.7 ± 42.3) min, and hypothermic circulatory arrest time was (9.6 ± 8.1) min. Three patients died in hospital, with a mortality rate of 5.8%. Fifteen patients (28.8%) had mild postoperative aortic regurgitation. The follow-up duration was 40 ± 12 (range, 21-66) months. Five patients (10.2%) developed moderate to severe aortic regurgitation and 3 (6.1%) died during the follow-up period.

CONCLUSIONS

The application of patches for aortic sinus reconstruction is a relatively easy method in aortic valve-sparing root reconstruction for acute type A aortic dissection involving the aortic sinus. The clinical and follow-up results are favorable.

Engineering analysis of aortic wall stress and root dilatation in the V-shape surgery for treatment of ascending aortic aneurysms

OBJECTIVES

The study objective was to evaluate the aortic wall stress and root dilatation before and after the novel V-shape surgery for the treatment of ascending aortic aneurysms and root ectasia.

METHODS

Clinical cardiac computed tomography images were obtained for 14 patients [median age, 65 years (range, 33-78); 10 (71%) males] who underwent the V-shape surgery. For 10 of the 14 patients, the computed tomography images of the whole aorta pre- and post-surgery were available, and finite element simulations were performed to obtain the stress distributions of the aortic wall at pre- and post-surgery states. For 6 of the 14 patients, the computed tomography images of the aortic root were available at 2 follow-up time points post-surgery (Post 1, within 4 months after surgery and Post 2, about 20-52 months from Post 1). We analysed the root dilatation post-surgery using change of the effective diameter of the root at the two time points and investigated the relationship between root wall stress and root dilatation.

RESULTS

The mean and peak max-principal stresses of the aortic root exhibit a significant reduction, P=0.002 between pre- and post-surgery for both root mean stress (median among the 10 patients presurgery, 285.46 kPa; post-surgery, 199.46 kPa) and root peak stress (median presurgery, 466.66 kPa; post-surgery, 342.40 kPa). The mean and peak max-principal stresses of the ascending aorta also decrease significantly from pre- to post-surgery, with P=0.004 for the mean value (median presurgery, 296.48 kPa; post-surgery, 183.87 kPa), and P=0.002 for the peak value (median presurgery, 449.73 kPa; post-surgery, 282.89 kPa), respectively. The aortic root diameter after the surgery has an average dilatation of 5.01% in total and 2.15%/year. Larger root stress results in larger root dilatation.

CONCLUSIONS

This study marks the first biomechanical analysis of the novel V-shape surgery. The study has demonstrated significant reduction in wall stress of the aortic root repaired by the surgery. The root was able to dilate mildly post-surgery. Wall stress could be a critical factor for the dilatation since larger root stress results in larger root dilatation. The dilated aortic root within 4 years after surgery is still much smaller than that of presurgery.

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.

Florida sleeve technique for a right sinus of Valsalva aneurysm: a case report

BACKGROUND

Florida sleeve technique was reported by Hess et al. as a new technique of valve sparing aortic root replacement without the requirement of entire aortic root wall resection and coronary artery reconstruction. We present a rare case of an unruptured aneurysm of the right sinus of Valsalva that was successfully treated with resection of the aneurysm and the Florida sleeve technique.

CASE PRESENTATION

A 72-year-old man was admitted for the treatment of an unruptured aneurysm of the right sinus of Valsalva. Computed tomography showed an aneurysm of the right sinus of Valsalva measuring > 40 mm and protruding into the right ventricular outflow tract. The aneurysm dilated up to 5 mm per year, and the left sinus of Valsalva and non-coronary sinus of Valsalva also showed dilation, and he underwent resection of only the right sinus of Valsalva aneurysm and valve sparing aortic root replacement with the Florida sleeve technique.

CONCLUSIONS

We performed valve-sparing aortic root replacement with the Florida sleeve technique. It could reduce surgical risks and prevent a dilatation of the residual sinus of Valsalva through coverage with a graft for a long term.

The evolution of surgical and medical treatment of aortic root aneurysm

Since first report of aortic root replacement in 1968, the surgical risk and long term outcome of patients with aortic root aneurysm have been continuously improving. In the last 30 years, the surgical approach is also evolving towards more valve conservation with prophylactical intervention at an earlier clinical stage. Translational research has also led to emerging surgical innovation and new drug therapy. Their efficacies are currently under vigorous clinical trials and evaluations.

Partial aortic root remodeling in case of ascending aortic aneurysms

OBJECTIVE

In degenerative ascending aortic aneurysms (AAAs), the pathological process may extend into the aortic root, causing aortic regurgitation (AR). As often one or two sinuses are involved, ascending aorta replacement should be associated with selected sinus replacement.

METHODS

Thirty patients (21 men and 9 women; mean ± SD age, 70.0 ± 10.4) were operated on for ascending aorta and selected sinus replacement. All patients had degenerative AAA with sinotubular junction and partial root dilatation: one or two sinuses of Valsalva were involved. Mild to moderate-severe AR was present in all patients. The mean ± SD logistic EuroSCORE 1 was 15.4 ± 12.5. Twenty patients had ascending aorta replacement associated with noncoronary sinus replacement; 8 patients, associated with both right and noncoronary sinuses; 1 patient, associated with both left and noncoronary sinuses; and 1 patient, associated with left coronary sinus alone.

RESULTS

There were no hospital or late deaths. No thromboembolic event or bleeding complications were reported. Postoperative echocardiography did not show significant AR, and computed tomographic scanning revealed a normal positioning of the vascular graft in the ascending aorta.

CONCLUSIONS

Remodeling of the sinotubular junction with selected sinus replacement in degenerative AAA is a valuable approach for aortic root remodeling, leading to a significant reduction of AR when the aortic leaflets are normal.

Proteomic profiling of medial degeneration in human ascending aorta

OBJECTIVE

The objective of this study was the construction of a reference map for aortic medial degeneration by a proteomic approach.

DESIGN AND METHODS

A proteomic profiling of the media of human ascending aorta was performed by two-dimensional electrophoresis and MALDI-TOF mass spectrometry.

RESULTS

A reliable protocol for two-dimensional electrophoresis analysis of human aortic media proteins was developed allowing the selection and identification of 52 spots. Protein identifications revealed that the predominant vascular smooth muscle cell proteins isolated from grade 1 aortic medial degeneration (MD) included proteins involved in muscle contraction, protein folding, cytoskeletal structure and metabolic processes, and those with antioxidant or transport functions. The most populated functional classes were those related to muscle contraction and cytoskeletal proteins, including actin, calmodulin, calponin, myosin light chain, tropomyosin, vimentin, profilin and transgelin.

CONCLUSIONS

The obtained aortic MD proteomic profile provides a relevant background for future studies aimed to find further specific molecular changes potentially related to the aortic MD process.

Comparison of three different surgical methods in aortic root aneurysms: long-term results

BACKGROUND

Degenerative ascending aortic aneurysms frequently present with aortic valve pathology. If only the noncoronary sinus of Valsalva is dilated, replacement of the noncoronary sinus by tailoring the supracoronary graft with or without aortic valve replacement (AVR) can be a simple operation strategy. We sought to describe our experiences in this kind of operation, and compare them with a relatively homogeneous group of patients who underwent the classical Bentall operation.

METHODS

Between January 1997 and June 2007, 99 patients who had dilated ascending aortas with root dilatation and aortic valve pathology underwent operation. Patients were divided into three groups according to the surgical procedure. Classical Bentall operation was applied in 54 patients with dilated sinuses (Group 1). The other patients with dilated noncoronary sinus underwent either ascending aortic replacement with noncoronary sinus replacement (NSR, n = 27) (Group 2), or separate AVR and ascending aortic replacement with NSR (AVR + NSR, n = 18) (Group 3).

RESULTS

There were significant reduction of aortic root in Group 2 (Z =-4.560, p < 0.001), and Group 3 (Z =-3.758, p < 0.001). Degree of aortic regurgitation was decreased from 1.56 +/- 0.5 to 0.67 +/- 0.5 postoperatively in Group 2 (Z =-3.874, p < 0.001). Hospital mortality was six (6.1%) (three in Group 1; three in Group 2). Late mortality rate was 6.1% (three in Group 1, three in Group 2). The type of operation was not found to be an independent predictor of overall mortality. No patients in the NSR and AVR-NSR groups had aortic root aneurysm, and there were no reoperations or verified deaths caused by aortic root aneurysm in these patients.

CONCLUSIONS

Noncoronary cusp replacement for aortic root remodeling in patients with ascending aortic aneurysm is a technically simple and durable operation. Short- and mid-term results of this method were favorable compared to the Bentall procedure.

Ascending aorta dilatation in aortic valve disease: morphological analysis of medial changes

We investigated whether and how the severity of medial degeneration lesions varies along the circumference of the dilated intrapericardial aorta. Two groups of aortic wall specimens, respectively harvested in the convexity and concavity of ascending aorta in 72 patients undergoing surgery for dilatation of the intrapericardial aorta associated with aortic valve disease, were separately sent for pathology, morphometry, and ultrastructural examination. Cystic medial necrosis, fibrosis, and elastic fiber fragmentation were classified into three degrees of severity; their mean degree and morphometric findings in the convexity and in the concavity specimens were compared by paired t-test. Correlation between echocardiographic degree of aortic dilatation and severity of medial degeneration was assessed separately for each of the two groups of specimens. Morphologically, medial degeneration was found in all cases; a higher mean degree was found in the convexity group (2.39 +/- 0.58 vs 1.44 +/- 0.65 in the concavity group; P < 0.001). At morphometry normal smooth muscle cells in the convexity specimens were significantly reduced (P = 0.007); the length (P = 0.012) and number (P = 0.009) of elastic fibers reduced and increased, respectively. Moreover, in the convexity specimens a significantly smaller amount of smooth muscle cells and an increase of immunohistochemical labeling of apoptosis-associated proteins in the subintimal layer of the media was noticed. Correlation between aortic ratio and medial degeneration degree was significant in the convexity group (P < 0.001), but not in the concavity group (P = 0.249). Scanning electron microscopy analysis confirmed morphological results and allowed us to better distinguish the early pathological cavities from the microvessels, which were in the outer media in normal aorta and ubiquitous in aortitis or atherosclerosis. Electron transmission microscopy analysis showed changes in the extracellular matrix and smooth muscle cells, and these changes increased from the intima to the adventitial layer of the media. In dilated intrapericardial aorta, medial degeneration changes and expression of apoptosis-associated proteins are more marked in the ascending aorta convexity, likely due to hemodynamic stress asymmetry. Ultrastructural findings allow us to distinguish the early medial changes not yet evident on light microscopy.

Repair of Bicuspid Aortic Valves in Patients With Aortic Regurgitation

Background— Bicuspid aortic valve regurgitation can be caused by a defect in the valve itself or by dysfunction of one or more components of the aortic root complex. A successful repair thus requires correction of all aspects of the problem simultaneously. We review our experience addressing both the valve and the aortic root when correcting bicuspid valve regurgitation.

Methods and Results— Between 1996 and 2004, we treated 68 patients for aortic regurgitation. Thirty patients had isolated aortic regurgitation, and 38 had an associated ascending aortic aneurysm. All patients were treated using a standardized and integrated surgical technique, which included resection of the median raphe or leaflet plication, subcommissural annuloplasty, reinforcement of the leaflet free edge, and sinotubular junction plication. In the 38 patients with proximal aortic dilatation, reimplantation or remodeling of the aortic root was performed. Immediate postoperative echocardiography showed grade ≤1 aortic regurgitation in all patients. Three patients nonetheless needed an early re-operation because of recurrent regurgitation. No hospital mortality was observed. At a mean follow-up of 34 months after surgery, all patients were in New York Heart Association (NYHA) class 1 or 2. Two patients needed a re-operation (23 and 92 months, respectively). Echocardiographic follow-up showed no progression of the regurgitation in 58 surviving patients. Four patients progressed to grade 2 regurgitation.

Conclusion— Our data indicate that regurgitant bicuspid aortic valves, whether alone or in association with a proximal aortic dilatation, can be repaired successfully provided that both the valve and the aortic root problems are treated simultaneously.

Valve-Sparing Aortic Root Repair With Patch Technique

BACKGROUND

In the valve-sparing aortic root repair technique presented, each pathologic sinus is replaced with a teardrop-shaped patch. In this study, the clinical and echocardiographic results after the first 20 procedures are evaluated.

METHODS

Between September 2000 and May 2004, 20 patients underwent aortic root repair using a patch technique. Eight patients had an acute type A aortic dissection and 12 patients had an aneurysm of the ascending aorta. In 12 cases, the aortic root was reconstructed with three patches, in 1 case with two patches, and in 7 cases with one patch.

RESULTS

The postoperative echocardiography at discharge showed no aortic regurgitation in 15 cases and trivial regurgitation in 5 cases. Three patients with aortic dissection as an initial pathologic diagnosis died during a median follow-up period of 14.5 months (range, 0.5 to 32 months). At the time of follow-up, the echocardiographic findings in all 17 survivors remained unchanged from the early postoperative examinations. Median peak and mean transvalvular gradients were 8 mm Hg (range, 3.2 to 14 mm Hg) and 4 mm Hg (range, 1.7 to 6 mm Hg), respectively.

CONCLUSIONS

The technique presented allows an individualized reconstruction of the sinuses of Valsalva, a simplified sizing of the vascular graft, and the creation of a new sinotubular junction resulting in good hemodynamic conditions. The technique is especially advantageous in patients in whom replacement of all sinuses is not necessary.

Femoral Versus Aortic Cannulation for Surgery of Chronic Ascending Aortic Aneurysm

BACKGROUND

Femoral artery cannulation and retrograde arterial perfusion have been postulated to increase the risk of cerebral embolism. In this study, the impact of the arterial cannulation site on the perioperative results after proximal aortic surgery is evaluated.

METHODS

Between January 1996 and December 2002, a total of 327 patients underwent proximal aortic repair for chronic non-dissected aortic disease. The arterial inflow was established by cannulation of the aortic arch (group A) or the femoral artery (group F) in 166 and 161 patients, respectively.

RESULTS

The early 30-day mortality was 0.9% (3 patients [1 patient in group A and 2 patients in group F]). The overall rate of early focal neurologic dysfunction (permanent and transient) was 4% (13 patients) and there was no significant difference between the two groups (4.2% vs 3.7%). Due to an intraoperative injury of the arterial wall, there were 6 repairs (3.6%) of the aortic arch in group A and 1 repair (0.6%) of the femoral artery in group F. The univariable examination of preoperative and intraoperative variables demonstrated that hypertension and increased cholesterol level could be possible independent risk factors for neurologic morbidity. In the following stepwise logistic regression, only the preoperative hypercholesterolemia was identified as an independent predictor for postoperative focal neurologic dysfunction.

CONCLUSIONS

The arterial inflow via the femoral artery and the subsequent retrograde perfusion during cardiopulmonary bypass do not increase the risk of neurologic complications in patients who undergo proximal aortic repair due to chronic non-dissected aortic aneurysm. Because there is an increased risk of aortic wall injury during cannulation, the femoral artery seems to be more suitable in these cases for cannulation than the proximal aorta.