Bioprosthetic Valves for Lifetime Management of Aortic Stenosis: Pearls and Pitfalls.

This review explores the use of bioprosthetic valves for the lifetime management of patients with aortic stenosis, considering recent advancements in surgical (SAV) and transcatheter bioprostheses (TAV). We examine the strengths and challenges of each approach and their long-term implications. We highlight differences among surgical bioprostheses regarding durability and consider novel surgical valves such as the Inspiris Resilia, Intuity rapid deployment, and Perceval sutureless bioprostheses. The impact of hemodynamics on the performance and durability of these prostheses is discussed, as well as the benefits and considerations of aortic root enlargement during Surgical Aortic Valve Replacement (SAVR). Alternative surgical methods like the Ross procedure and the Ozaki technique are also considered. Addressing bioprosthesis failure, we compare TAV-in-SAV with redo SAVR. Challenges with TAVR, such as TAV explantation and considerations for coronary circulation, are outlined. Finally, we explore the potential challenges and limitations of several clinical strategies, including the TAVR-first approach, in the context of aortic stenosis lifetime management. This concise review provides a snapshot of the current landscape in aortic bioprostheses for physicians and surgeons.

Investigation of the Role of BMP2 and -4 in ASD, VSD and Complex Congenital Heart Disease.

Congenital heart malformations (CHMs) make up between 2 and 3% of annual human births. Bone morphogenetic proteins (BMPs) signalling is required for chamber myocardium development. We examined for possible molecular defects in the bone morphogenetic protein 2 and 4 (BMP2, -4) genes by sequencing analysis of all coding exons, as well as possible transcription or protein expression deregulation by real-time PCR and ELISA, respectively, in 52 heart biopsies with congenital malformations (atrial septal defect (ASD), ventricular septal defect (VSD), tetralogy ofFallot (ToF) and complex cases) compared to 10 non-congenital heart disease (CHD) hearts. No loss of function mutations was found; only synonymous single nucleotide polymorphisms (SNPs) in the BMP2 and BMP4 genes were found. Deregulation of the mRNA expression and co-expression profile of the two genes (BMP2/BMP4) was observed in the affected compared to the normal hearts. BMP2 and -4 protein expression levels were similar in normal and affected hearts. This is the first study assessing the role of BMP-2 and 4 in congenital heart malformations. Our analysis did not reveal molecular defects in the BMP2 and -4 genes that could support a causal relationship with the congenital defects present in our patients. Importantly, sustained mRNA and protein expression of BMP2 and -4 in CHD cases compared to controls indicates possible temporal epigenetic, microRNA or post-transcriptional regulation mechanisms governing the initial stages of cardiac malformation.

Disseminated Intravascular Coagulation Post Endovascular Aortic Repair.

BACKGROUND: Disseminated Intravascular Coagulation (DIC) after Endo-Vascular Aneurysm Repair (EVAR) is a highly uncommon clinical entity. With only a few case-reports available, its management strategy still remains enigmatic. OBJECTIVES: The purpose of this study was to retrieve, synthesize, and appraise all existing data for DIC after EVAR. MATERIALS AND METHODS: All published articles regarding DIC post-EVAR were identified from 3 major databases and analyzed. Clinical parameters, predisposing factors, along with mortality and morbidly were assessed. RESULTS: The total number of publications included in the review was 15 describing 17 cases. DIC presented with a broad spectrum of clinical manifestations, while the time of diagnosis varied significantly. Endoleak was the main causative factor, with an incidence reaching 71%. The mortality of DIC after EVAR reached 29%, regardless of the therapeutic approach chosen. DIC was treated effectively in 47% of the patients (8/17), with better outcomes among patients who received conservative therapy or among those who were submitted to endovascular interventions. CONCLUSIONS: DIC after EVAR, although rare, is a potentially lethal clinical condition which requires prompt diagnosis and urgent medical consideration. Treatment of endoleak may help in quick restoration of normal parameters.

Intraoperative accurate assessment of septal myectomy for hypertrophic obstructive cardiomyopathy (HOCM).

Surgical restoration of the left ventricular outflow tract (LVOT) is necessary for patients suffering from hypertrophic obstructive cardiomyopathy (HOCM), when symptoms are present despite the administration of medical treatment. One point of great significance during the procedure is the evaluation of the LVOT gradient after completion of septal myectomy. Most physicians choose to measure this value by transesophageal echocardiography (TEE) in combination with the direct measurement with the use of needles inserted into the aorta and left ventricle. In this article, we present the implementation of a new technique to estimate the peak-to-peak pressure gradient between the left ventricle and the aorta intraoperatively using a single double lumen central venous catheter inserted through the antegrade cardioplegia cannulation site across the aortic valve into the left ventricle.

Regional and directional variations in the layer-specific resistance to tear propagation in ascending thoracic aortic aneurysms.

Aortic dissection often initiates a few centimeters distal to the coronary ostia in the right lateral wall, with an intimal-medial tear that tends to be transversely directed and occupy half of the aortic circumference, sometimes less, but seldom the entire circumference. To elucidate these clinical observations, tear tests were presently used to determine the layer-specific resistance to tear propagation in ascending thoracic aortic aneurysms, assessing variations over the four circumferential quadrants and two directions. Aneurysmal tissue strips of standardized dimensions from sixteen patients were anatomically separated into layers (seven hundred and twelve) and an incision made along one-third of their length. They underwent tear testing via uniaxial loading and then unloading before crack propagation had proceeded along their complete length. The average tear tension and tear energy per reference area generated were many-fold greater in outer- (adventitial) compared to inner- (intimal with small medial portion) and middle-layer (medial) strips, explaining why the tear is restricted to the inner wall. They were greater in inner- compared to middle-layer strips of the anterior and left lateral quadrants, suggesting that the tear will propagate to the less-resistant media even if initiated in the intima. In most longitudinally-cut middle- and inner-layer strips, the cracks deviated toward the circumferential direction and tore out through the side, justifying the circumferential course of the tear. Both fracture parameters were significantly higher in the right than the left lateral quadrant in outer-layer strips and the anterior quadrant in middle-layer strips, potentially affecting the circumferential extent of the tear.

Failure properties of ascending thoracic aortic aneurysms with dysfunctional tricuspid aortic valves.

OBJECTIVES: Ascending thoracic aortic aneurysms (ATAAs) often coexist with dysfunctional tricuspid aortic valves (TAVs). How valvular pathology relates to the aortic wall mechanical properties requires detailed examination. METHODS: Intact-wall and layer-specific mechanical properties from 40 and 21 patients with TAV-ATAAs, respectively, were studied using uniaxial tensile testing, longitudinally and circumferentially. Failure stress (tensile strength), failure stretch (extensibility) and peak elastic modulus (stiffness) measurements, along with histological assays of thickness and elastin/collagen contents, were compared among patients with no valvular pathology (NVP), aortic stenosis (AS) or aortic insufficiency (AI). RESULTS: Intact-wall stiffness longitudinally and medial strength and stiffness, in either direction, were significantly lower in AI patients than in AS and NVP patients. Intact-wall/medial thickness and extensibility in either direction were significantly lower in AS patients than in AI and NVP patients. In contrast, intact-wall/medial stiffness circumferentially was significantly higher in AS patients than in NVP patients, consistent with the significantly increased medial collagen in AS patients. Failure properties and medial thickness and elastin/collagen contents were significantly lower (more impaired) in females. The left lateral was the thickest quadrant in NVP patients, but the 4 quadrants were equally thick in AS and AI patients. There were significant differences in strength and stiffness among quadrants, which varied however in the 3 patient groups. CONCLUSIONS: The aortic wall load-bearing capacity was impaired in patients with ATAA in the presence of TAV stenosis or insufficiency. These findings lend biomechanical support to the current guidelines suggesting lower thresholds for elective ascending aorta replacement in cases of aortic valve surgery.

Regional distribution of delamination strength in ascending thoracic aortic aneurysms.

Considering that the biomechanical factors underlying aortic dissection remain poorly understood as does the rationale for the anatomic localization of the dissection channel, we have attempted to determine the regional distribution of delamination/tensile strengths of ascending thoracic aortic aneurysm wall tissue. Whole aneurysms were taken from seventeen patients undergoing elective surgery and cut into a couple of specimens per quadrant and direction. The specimens were subjected to delamination- and tensile-testing, from which average peel tension (=delamination strength) and failure stress (=tensile strength) were assessed. Histology revealed no differences with region and direction in the roughness of the delaminated surfaces of the inner (intima with most of media) and outer layers (leftover media with adventitia). Compared to the right, the left lateral region exhibited significantly higher thickness and peel tension in both directions, but lower failure stress of the inner and outer layers longitudinally. Failure stress of the inner layers mostly but also of the outer layers was significantly higher circumferentially than longitudinally, with significantly higher values for the outer compared to the inner layers. Differing heterogeneity was evidenced in the delamination and tensile strength of aneurysmal tissue, with important implications for dissection propagation. Particularly, the increased resistance to propagation in the left lateral region helps address the question why part of the circumference, characteristically the right lateral wall, is involved by the dissection and the other part of the aortic wall remains intact. The deterioration of delamination strength with aging suggests the greater potential of aged individuals for dissection propagation.

Identification of regional/layer differences in failure properties and thickness as important biomechanical factors responsible for the initiation of aortic dissections.

Thoracic aortic dissections involving the ascending aorta represent one of the most dramatic and lethal emergencies in cardiovascular surgery. It is therefore critical to identify the mechanisms driving them and biomechanical analyses hold great clinical promise, since rupture/dissection occur when aortic wall strength is unable to withstand hemodynamic stresses. Although several studies have been done on the biomechanical properties of thoracic aortic aneurysms, few data are available about thoracic aortic dissections. Detailed mechanical tests with measurement of tissue thickness and failure properties were performed with a tensile-testing device on 445 standardized specimens, corresponding to 19 measurement sites per inner (intima with most of media)/outer layer (leftover media with adventitia); harvested from twelve patients undergoing emergent surgical repair for type A dissection. Our data suggested inherent differences in tissue properties between the origin of dissection and distal locations, i.e. thinner and stiffer inner layers that might render them more vulnerable to tearing despite their increased strength. The strength of tissue circumferentially was greater than that longitudinally, likely determining the direction of tear. The relative strengths of the inner: ∼{65,40}N/cm2 and outer layer: ∼{350,270}N/cm2 in the two principal directions of dissected tissue were differentiated from the intima: ∼{100,75}N/cm2, media: ∼{150,55}N/cm2, and adventitia: ∼{270,190}N/cm2 of non-dissected ascending aortic aneurysms (Sokolis et al., 2012), in favor of weaker inner and stronger outer layers, allowing an explanation as to why the presently-studied tissue suffered dissection, i.e. tear of the inner layers, and not rupture, i.e. full tearing across the entire wall thickness.

Effect of Aneurysm and Bicuspid Aortic Valve on Layer-Specific Ascending Aorta Mechanics.

BACKGROUND: Previous studies have not examined the participation of intimal, medial, and adventitial layers in providing mechanical strength to the ascending thoracic aortic aneurysm (ATAA) wall compared with the nonaneurysmal aorta. In this study we compared the mechanical properties of intact wall and its layers among ATAAs and nonaneurysmal aortas, with explicit consideration of the effects of valve morphology; that is, bicuspid aortic valve (BAV) versus tricuspid aortic valve (TAV), and aortic quadrant. METHODS: Whole ATAAs were taken from patients undergoing elective repair and nonaneurysmal aortas from age-matched autopsy subjects. These were cut into 2 circumferential and longitudinal tissue strips for the intact wall and its layers per quadrant, permitting examination of the aortic wall as a multilayered structure. Tissue underwent tensile testing for determination of failure properties. RESULTS: Intact wall and layer-specific failure stretches (ie, extensibilities) were significantly greater in nonaneurysmal and BAV-ATAA than in TAV-ATAA, unaccounted for by elastin/collagen content changes. Intact wall failure stress (ie, strength) was significantly greater in BAV-ATAA than in TAV-ATAA, in analogy with medial failure stress. Failure stress and stretch associated negatively with age in most subject groups, layers, and intact wall, but failure stretch correlated positively with residual stretch (ie, structural bonds between layers). CONCLUSIONS: No mechanical vulnerability of BAV-ATAA was found, corroborating current conservative guidelines regarding the management of bicuspid aortopathy. Weakening and added vulnerability was found in patients with valvular deficiency, aortic root aneurysm, hypertension, and hyperlipidemia. Aging led to increased susceptibility to dissection initiation or full rupture, or both, in both patient classes.

Comparison of the Feasibility and Safety of Nasotracheal Suctioning With Curved Edge Catheter Versus Conventional Suction Catheter in Critically Ill Subjects: A Prospective Randomized Crossover Trial.

BACKGROUND: Nasotracheal suctioning (NTS) is accomplished by inserting a suction catheter into the trachea through the nasopharynx. It is a useful procedure in critically ill patients whose ability to cough and mobilize secretions is impaired. Ιt was assumed that using a suction catheter with an angular tip would facilitate entry into the trachea. The primary outcome was the success rate and the ease of insertion by using a curved edge catheter (Tiemann type) compared with a conventional suction catheter. The secondary outcome was the monitoring of subject's vital signs during the intervention. METHODS: Non-intubated subjects hospitalized in 2 adult ICUs underwent 2 consecutive NTSs each, using either a 14 French curved edge catheter or a 14 French conventional suction catheter, randomly. RESULTS: Twenty subjects with a mean age of 75.5 y were enrolled for a time period of 5 months. The tracheal access success rate was 19/52 (successful/unsuccessful attempts) using a curved edge catheter (36.5%, 95% CI 23.6-51.0%) compared with 12/130 (9.2%, 95% CI 4.8-15.5%) using a conventional suction catheter. The insertion was 5.6 times more likely to be achieved by using a curved edge catheter (odds ratio 5.66, 95% CI 2.49-12.84, P < .001). The number of attempts required to succeed in the insertion was significantly lower when using a curved edge catheter than when using a conventional suction catheter (for nasopharynx, median [range] of 1 [1] versus 2.5 [8], P = .001; for trachea, median [range] of 2 [9] versus 9 [9], P = .002). The time required for successful insertion into the nasopharynx and trachea was significantly shorter when using a curved edge catheter than when using a conventional suction catheter (for nasopharynx, median [range] of 3 [11] s versus 5.3 [18] s, P = .038; for trachea, median [range] of 6 [27] s versus 20 [25] s, P = .002). The traumatic rate (percentage of catheters with blood present on the tip) was exactly the same for both catheters (30%). CONCLUSIONS: It is more likely that tracheal access will be achieved using a curved edge catheter. A shorter process time and fewer attempts are required for successful NTS using a curved edge catheter, and it seems to be an equally safe procedure. (ClinicalTrials.gov registration NCT02261428.).

Patient characteristics and predictors of mortality associated with pericardial decompression syndrome: a comprehensive analysis of published cases.

BACKGROUND: Pericardial decompression syndrome (PDS) is a rare and potentially fatal complication of pericardial drainage, either by needle pericardiocentesis or surgical pericardiostomy. It manifests with paradoxical hemodynamic deterioration and/or pulmonary edema, commonly associated with ventricular dysfunction. We sought to elucidate factors associated with mortality in PDS. METHODS: MEDLINE was systematically searched for PDS case reports and case series published between 1983 and 2013. For this analysis, clinical variables, echocardiographic and hemodynamic variables, details of drainage procedure and clinical outcomes were collected for each case. RESULTS: A total of 35 cases (12 male, 23 female) were identified. PDS developed after pericardiocentesis, pericardiostomy, or both, in 18, 16, and one patients, respectively. Cardiac tamponade was the indication in 33 cases (94%). The mean age was 47 ± 17 years. The mean amount of effusion drained was 888 mL. The minimum amount of effusion drained was 450 mL. The onset of PDS after the procedure varied widely, ranging from 'immediate' to 48 hours. Presentations included 10 (29%) with cardiogenic pulmonary edema without shock, 14 (40%) with left ventricular failure, three (9%) with right ventricular failure, seven (20%) with biventricular failure, and one (3%) with non-cardiogenic pulmonary edema. Ten patients (29%) died of PDS. Mortality was associated only with surgical drainage (p<0.001). Severe LV dysfunction normalized in PDS survivors. CONCLUSIONS: PDS is a rare complication of pericardial drainage with a high mortality rate. Surgical pericardiostomy was associated with mortality in PDS.