The Ascyrus Medical Dissection Stent: A One-Fits-All Strategy for the Treatment of Acute Type A Aortic Dissection?

The treatment of DeBakey type I aortic dissection remains a major challenge in the field of aortic surgery. To upgrade the standard of care hemiarch replacement, a novel device called an "Ascyrus Medical Dissection Stent" (AMDS) is now available. This hybrid device composed of a proximal polytetrafluoroethylene cuff and a distal non-covered nitinol stent is inserted into the aortic arch and the descending thoracic aorta during hypothermic circulatory arrest in addition to hemiarch replacement. Due to its specific design, it may result in a reduced risk for distal anastomotic new entries, the effective restoration of branch vessel malperfusion and positive aortic remodeling. In this narrative review, we provide an overview about the indications and the technical use of the AMDS. Additionally, we summarize the current available literature and discuss potential pitfalls in the application of the AMDS regarding device failure and aortic re-intervention.

Hybrid noncovered open stents in repair of DeBakey type 1 acute aortic dissections.

OBJECTIVES: The indications for use, evidence base and experience with the novel noncovered open hybrid surgical stents for acute type A aortic dissection repair for concurrent stabilization of the 'downstream' aorta remains limited. We review the evidence base and the development of these stents. METHODS: Data were collected from Pubmed/Medline literature search to develop and review the evidence base for safety and efficacy of non-covered surgical stents. Existing guidelines for use and developments were reviewed. RESULTS: A single randomized control trial and 4 single-centre studies were included in the review with a total worldwide experience of 241 patients. The deployment was easy and did not add significantly to the primary operation. The mortality and new stroke ranged from 6.3-18.7%. Safe and complete deployment was accomplished in 92-100%. There was no device-related reintervention. There was a significant improvement in malperfusion in over 90% of the cases with varying degrees of remodelling (60-90%) of the downstream aorta. CONCLUSIONS: Open noncovered stent grafts represent a major technical advancement as an adjunct procedure for acute dissection repairs, e.g. hemiarch repair. It has potential for wider use by non-aortic surgeons due to simplicity of technique. Limited safety and efficacy data confirm the device to be safe, feasible and reproducible with potential for wider adoption. However, long-term trial and registry data are required before recommendations for standard use outside of high-volume experienced aortic centres.

Minimally Invasive Approaches to Mitral Valve Surgery: Where Are We Now? A Narrative Review.

Minimally invasive mitral valve surgery (MiMVS) has been increasing in prevalence. This review will focus on the approaches, the clinical outcomes, and patient selection for MiMVS. There are four minimally invasive approaches to the mitral valve: Right mini-thoracotomy, both video-assisted and fully endoscopic, robotic mitral surgery, and transapical, beating heart off-pump neochordal repair. Advantages over conventional surgery include less blood loss and transfusion, improved postoperative mobility, shorter length of stay, less postoperative atrial fibrillation, fewer surgical site infections, and improved cosmesis. This range of minimally invasive techniques will continue to evolve, providing options that are tailored for different patient populations.

Relation of body mass index to long-term survival and cardiac remodelling for patients undergoing mitral valve replacement surgery.

BACKGROUND AND AIMS: Studies have demonstrated that obesity is paradoxically associated with reduced mortality following cardiac surgery. However, these studies have treated various types of cardiac surgery as a single entity. With mitral valve (MV) surgeries being the fastest-growing cardiac surgical interventions in North America, the purpose of this study was to identify the impact of body mass index (BMI) on long-term survival and cardiac remodelling of patients undergoing MV replacement (MVR). METHODS AND RESULTS: In this retrospective, single-center study, 1071 adult patients who underwent an MVR between 2004 and 2018 were stratified into five BMI groups (<20, 20-24.9, 25-29.9, 30-34.9, >35). Cox proportional hazard regression models were used to determine the association between BMI and all-cause mortality. Patients who were underweight had significantly higher all-cause mortality rates at the longest follow-up (median 8.2 years) than patients with normal weight (p = 0.01). Patients who were in the obese group had significantly higher readmission rates due to myocardial infarction (MI) at the longest follow-up (p = 0.017). Subgroup analysis revealed a significant increase in long-term all-cause mortality for female patients who were underweight. Significant changes in left atrial size, mitral valve peak and mean gradients were seen in all BMI groups. CONCLUSIONS: For patients undergoing mitral valve replacement, BMI is unrelated to operative outcomes except for patients who are underweight.

The Use of the Ascyrus Medical Dissection Stent in Acute Type A Aortic Dissection Repair Reduces Distal Anastomotic New Entry Tear.

BACKGROUND: A distal anastomotic new entry tear (DANE) can occur at the time of surgical repair for acute type A aortic dissection (ATAAD). This study aimed to compare the occurrence of DANE following a standard hemiarch repair with that following a hemiarch repair with an uncovered arch dissection stent. METHODS: All patients who received a hemiarch repair or a hemiarch repair with an Ascyrus Medical Dissection Stent (AMDS) for ATAAD from 2017 to 2021 were included. Baseline and intra- and postoperative characteristics were collected. All available pre- and postoperative computed tomographic scans were analysed. The primary outcome measures were the incidence of DANE, positive aortic remodelling, mortality, and aortic reintervention rates at last follow-up. RESULTS: A total of 114 patients underwent repair of Debakey I ATAAD during the study period with either an isolated hemiarch (n = 77) or a hemiarch with AMDS (n = 37). There was no significant difference in mortality (P = 0.768) or other in-hospital adverse events. During the follow-up period, DANE occurred in 43.3% (n = 26) of the isolated hemiarch group and in 11.8% (n = 4) of the hemiarch with AMDS group (P = 0.002). The incidence of false lumen thrombosis and obliteration favoured the AMDS group in the aortic arch (P = 0.029), the proximal descending thoracic aorta (P = 0.031), and level of pulmonary artery bifurcation (P = 0.044). CONCLUSIONS: The incidence of DANE is significantly reduced with the addition of an AMDS at the time of hemiarch repair for ATAAD repair. Further follow-up is necessary to identify late aortic complications that may have been prevented by reducing the incidence of postoperative DANE.

Assessment of a Novel, Adjustable Task Trainer for Cardiac Surgical Skills.

INTRODUCTION: A recent needs assessment in Canadian cardiac surgery programs identified the desire for a coronary artery bypass (CABG) and aortic valve replacement (AVR) simulation model for home practice. We aimed to develop and assess a portable, adjustable task trainer for cardiac surgical skills with high functional task alignment. METHODS: Intraoperative measurements were taken from patients undergoing elective CABG and AVR (N = 30). Measurements were taken in 3 axes and used to create a chest cavity that resembles the mediastinal constraints of a patient undergoing CABG and AVR. The task trainer is adjustable on the following 3 levels: (1) size of the incision, (2) depth of the chest, and (3) relative position of coronary artery or aortic valve model within the chest. Three groups (novices, intermediates, and experts) of cardiac surgery members evaluated the task trainer for functional task alignment and construct validity. RESULTS: The CABG and AVR model had high functional task alignment. There was a high satisfaction for both models and all participants would recommend the AVR and CABG model as an educational tool. Performance time significantly differed between the groups for both models (CABG: P = 0.032 and AVR: P = 0.001), as well as number of errors (CABG: P = 0.04 and AVR: P = 0.043). CONCLUSIONS: Using real patient data, we were able to develop an adjustable task trainer for training principles of CABG and AVR. Our pilot study provides preliminary sources of evidence for validity and future study will look to assess transferability of skill to the operating room.

Enterococcus faecalis endocarditis resulting in annular rupture: a case report.

Enterococcus faecalis is the third most common organism to cause infective endocarditis and is associated with high rates of morbidity and mortality. E. faecalis infective endocarditis often presents with a subacute course and with nonspecific constitutional symptoms. Complications related to E. faecalis infective endocarditis are common and include embolic events, abscess formation and pseudoaneurysm formation. Contained annular rupture is a complication of E. faecalis infective endocarditis that, to the authors knowledge, has not been previously described in the literature. Herein, we present an unusual case of a 62-year-old male presenting with classical symptoms of E. faecalis infective endocarditis which resulted in an unusual complication of this condition, a contained annular rupture and the surgical management undertaken to correct this condition.

Enterococcus faecalis is the third most common organism to cause infection of the heart and heart valves and is associated with high rates of complications and death. Complications related to E. faecalis heart infections are common and include dislodging of infected material, abscess formation and injury to blood vessel walls. Contained rupture of the aortic valve annulus is a complication of E. faecalis infections that, to the authors knowledge, has not been previously described in the literature. Herein, we present an unusual case of a 62-year-old male presenting with classical symptoms of E. faecalis infection of the heart which resulted in an unusual complication of this condition, a contained annular rupture and the surgical management undertaken to correct this condition.

The influence of renal disease on outcomes and cardiac remodeling following surgical mitral valve replacement.

OBJECTIVES: Chronic kidney disease (CKD) is increasingly prevalent in patients undergoing mitral valve replacement (MVR). While CKD is known to result in suboptimal outcomes for patients with mitral valve disease, there is limited literature evaluating the long-term outcomes and cardiac remodeling of patients with CKD undergoing MVR. We present the first analysis coupling long-term outcomes of combined morbidity, mortality, and cardiac remodeling post-MVR in patients with CKD. METHODS: Patients with varying degrees of CKD undergoing MVR from 2004 to 2018 were compared. Patients were grouped by estimated glomerular filtration rate (eGFR) > 90 mL/min/1.73m2 (n = 109), 60-89 mL/min/1.73m2 (450), 30-59 mL/min/1.73m2 (449), < 30 mL/min/1.73m2 (60). The primary outcome was mortality. Secondary outcomes included measures of postoperative morbidity and cardiac remodeling. RESULTS: One-year mortality was significantly increased in patients with eGFR < 30 (p = 0.023). Mortality at 7 years was significantly increased in patients with eGFR < 30 mL/min/1.73m2 (p < 0.001). Multivariable regression analysis of 7-year all-cause mortality indicated an eGFR of 15 mL/min/1.73m2 (HR 4.03, 95% CI 2.54-6.40) and 30 mL/min/1.73m2 (HR 2.17 95% CI 1.55-3.05) were predictive of increased mortality. Reduced eGFR predicted the development of postoperative sepsis (p = 0.002), but not other morbidities. Positive cardiac remodeling of the left ventricle, left atrium, and valve gradients were identified postoperatively for patients with eGFR > 30 mL/min/1.73m2 while patients with eGFR < 30 mL/min/1.73m2 did not experience the same changes. CONCLUSIONS: CKD is predictive of inferior clinical and echocardiographic outcomes in patients undergoing MVR and consequently requires careful preoperative consideration and planning. Further investigation into optimizing the postoperative outcomes of this patient population is necessary.

Quantifying the immune response to a tissue-engineered porcine extracellular matrix.

Aim: Structural valvular deterioration of xenogenic heart valve replacements is thought to be due to a chronic immune response. We sought to engineer porcine extracellular matrix that elicits minimal inflammatory immune response. Materials & methods: Whole blood, bone marrow and pericardium were collected from patients undergoing elective cardiac surgery. Porcine extracellular matrix was decellularized, reseeded with homologous mesenchymal stem cells and exposed to whole blood. Results: DAPI stain confirmed the absence of cells after decellularization, and presence of mesenchymal stem cells after recellularization. There was a significant reduction in IL-1ß and TNF-α production in the recellularized matrix. Conclusion: Recellularization of porcine matrix is successful at attenuating the xenogenic immune response and may provide a suitable scaffold to address the current limitations of prosthetic heart valve replacements.

Deterioration of tissue heart valve replacements is thought to be due to a chronic immune response. We sought to remove cells from a pig derived tissue and replace those cells with human stem cells to create a scaffold that results in a reduced immune response. Whole blood, bone marrow and pericardium were collected from patients undergoing elective cardiac surgery. The pig derived tissue had the cells removed, were replaced with human stem cells and exposed to whole blood. Tissue stain confirmed the absence of cells after removal, and presence of stem cells after replacement of cells. There was a significant reduction in markers of immune response in the recellularized tissue. Removal of cells from pig derived tissue and replacement with human stem cells is successful at reducing the immune response to animal tissue and may provide a suitable scaffold to address the current limitations of heart valve replacement options.

Three-year outcomes of the Dissected Aorta Repair Through Stent Implantation trial.

OBJECTIVE: The study objective was to evaluate the clinical and radiographic outcomes of the Ascyrus Medical Dissection Stent in a prospective, nonrandomized, international study (Dissected Aorta Repair Through Stent Implantation) of patients with acute DeBakey type I aortic dissection. METHODS: The Ascyrus Medical Dissection Stent was used in combination with the standard surgical management of acute DeBakey type I aortic dissection I to treat patients with (56.5%, 26/46) and without (43.5%, 20/46) preoperative clinical and radiographic malperfusion. All patients had a primary entry tear in the ascending aorta, and 97.8% (45/46) were treated with a hemiarch repair. Median follow-up was 3 years. RESULTS: All 47 patients underwent emergency surgical repair with successful Ascyrus Medical Dissection Stent implantation. One patient was excluded from analysis due to use in iatrogenic dissection. Overall mortality at 30 days and 3 years was 13.0% (6/46) and 21.7% (10/46), respectively. Overall new stroke rate at 30 days was 15.2% (7/46). No devices were explanted at any time during the 3-year median follow-up. At 3 years, the total aortic diameter in zones 0, 1, and 2 decreased or remained stable in 91.7%, 72.7%, and 75.0%, respectively. The false lumen was completely or partially thrombosed in 90.5% in zone 0, 60.0% in zone 1, and 68.2% in zone 2 at 3 years. CONCLUSIONS: The use of the Ascyrus Medical Dissection Stent in the treatment of acute DeBakey type I aortic dissection I holds promise as a simple technology that enables repair of the aortic arch and proximal descending aorta, while promoting positive aortic remodeling. Ongoing follow-up of the Dissected Aorta Repair Through Stent Implantation trial will provide long-term, prospective, clinical outcomes and radiographic data on positive remodeling of the aortic arch.

Recellularized bovine pericardium with autologous mesenchymal stem cells reduces immune activation.

INTRODUCTION: Current bioprosthetic heart valve replacement options are limited by structural valvular deterioration (SVD) due to an immune response to the xenogenic scaffold. Autologous mesenchymal stem cell (MSC) recellularization is a method of concealing xenogenic scaffolds, preventing recipient immune recognition of xenogenic tissue heart valves, and potentially leading to reduction in SVD incidence. The purpose of this study is to examine the effects of autologous MSC recellularized tissue on the immune response of human whole blood to bovine pericardium (BP). We hypothesized that autologous MSC recellularization of BP will result in reduced pro-inflammatory cytokine production equivalent to autologous human pericardium. METHODS: Bone marrow, human pericardium, and whole blood were collected from adult patients undergoing elective cardiac surgery. Decellularized BP underwent recellularization with autologous MSCs, followed by co-incubation with autologous whole blood. Immunohistochemical, microscopic, and quantitative immune analysis approaches were used. RESULTS: We demonstrated that native BP, exposed to human whole blood, results in significant TNF-α and IL1ß production. When decellularized BP is recellularized with autologous MSCs and exposed to whole blood, there is a significant reduction in TNF-α and IL1ß production. Importantly, recellularized BP exposed to whole blood had similar production of TNF-α and IL1ß when compared to autologous human pericardium exposed to human whole blood. CONCLUSION: Our results suggest that preventing initial immune activation with autologous MSC recellularization may be an effective approach to decrease the recipient immune response, preventing recipient immune recognition of xenogeneic tissue engineered heart valves, and potentially leading to reduction in SVD incidence.

Coronary artery occlusion flap: An unusual case of spontaneous coronary artery dissection.

CASE REPORT: A 39-year-old female presented with chest pain, shortness of breath, and was diagnosed with ST-elevation myocardial infarction. Coronary angiogram revealed left main coronary artery (LMCA) spontaneous coronary artery dissection (SCAD). Following conservative treatment, the patient continued experiencing shortness of breath and chest pain. The cause of these symptoms was difficult to ascertain, even with further investigation. The patient underwent coronary artery bypass grafting, aortic valve replacement, and aortic root replacement with reimplantation of coronary buttons. Following aortotomy, a dissection flap formed by the SCAD was identified, intermittently occluding the LMCA. This was thought to cause their intermittent and severe heart failure symptoms as the flap would intermittently occlude the LMCA causing severe myocardial ischemia. CONCLUSION: This patient's presentation of a dissection flap intermittently occluding the LMCA demonstrates an abnormal manifestation of SCAD. Increased awareness of this presentation is imperative to ensure future cases are correctly identified and managed.

Pericardiectomy for Constrictive Pericarditis in a Young Patient With Erdheim-Chester Disease.

Erdheim-Chester Disease (ECD) is an extremely rare non-Langerhans histiocytosis that most often presents in the fifth to seventh decades of life. In this case report, we present a 34-year-old woman who underwent successful pericardiectomy for constrictive pericarditis secondary to ECD, which is the youngest reported patient with ECD to undergo pericardiectomy. (Level of Difficulty: Advanced.).

Sex differences in acute type A aortic dissection: a systematic review and meta-analysis.

INTRODUCTION: The objective of this study is to provide a comprehensive comparison of outcomes following acute type A aortic dissection (ATAAD) repair in males and females. EVIDENCE ACQUISITION: PubMed, Medline, and Web of Science were systematically searched by two authors for studies published from January 1st, 2000, to May 10th, 2021. Overall, 2405 articles were screened, and 16 were included in this review. Meta-analysis of the compiled data was performed. EVIDENCE SYNTHESIS: Pooled estimates indicated no difference in operative (odds ratio (OR) 1.00, 95% confidence interval (CI) 0.59-1.67, P=0.99, I2=52%), in-hospital (OR 0.78, 95% CI 0.56-1.08; P=0.13, I2=57%), and 30-day mortality (OR 1.09, 95% CI 0.83-1.43, P=0.52, I2=45%) between the sexes. However, males had significantly reduced 5-year mortality rates (OR 0.71, 95% CI 0.51-1.00, P=0.05, I2=45%). There was no difference between sexes in rates of postoperative stroke (OR 1.07, 95% CI 0.86-1.33, P=0.54, I2=0%), atrial fibrillation (OR 0.99, 95% CI 0.82-1.19, P=0.92, I2=0%), as well as mesenteric or limb ischemia (OR 0.73, 95% CI 0.22-2.43, P=0.61, I2=77%; OR 0.83, 95% CI 0.30-2.30, P=0.72, I2=76%, respectively). Males did experience significantly increased rates of acute renal failure and reoperation (OR 1.35, 95% CI 1.16-1.56, P=0.0001, I2=29%; OR 1.40, 95% CI 1.09-1.81, P=0.010, I2=42%). CONCLUSIONS: Composite analysis indicates that early mortality does not differ between the sexes; however, late outcomes favor males. Differences in preoperative presentation and subsequent procedure selection between the sexes likely contribute to the disparity in late outcomes. Decision-making for surgical treatment of ATAAD should account for sex-specific risk factors.

Mortality and morbidity of surgical and transcatheter mitral valve repair in octogenarians: A systematic review.

BACKGROUND: Valvular heart disease (VHD) is a prominent problem in healthcare today with mitral regurgitation (MR) being the leading cause of VHD in the elderly population. While mitral valve repair (MVr) surgery is one of the only options for the end-stage disease, octogenarians are often denied MVr due to concerns with operative mortality and postoperative morbidity. To provide information on this underrepresented group of surgical patients, a systematic approach was taken to review the mortality and morbidity rates of octogenarians who received MVr. METHODS: Pubmed and Medline were searched for articles containing outcomes of octogenarians receiving surgical mitral valve repair (SMVr) or transcatheter mitral valve repair (TMVr) published after 2000. Ten articles met the inclusion criteria for a total of 7968 patients included in the analysis using Microsoft Excel, Version 2105. RESULTS: Short-term mortality rates for SMVr and TMVr were 2.6% and 1.4% for in-hospital, and 7.8% and 3.3% for 30 days, respectively. The average incidence of stroke, acute kidney injury, infection, and major bleeding for SMVr were 3.2%, 11.2%, 7.7%, and 24%, respectively, and 0.3%, 6.7%, 2.7%, and 7.9% for TMVr, respectively. CONCLUSION: Octogenarians receiving SMVr or TMVr experienced similar rates of short-term mortality and morbidity as younger populations, and when considering life expectancy, midterm mortality was also similar. With these results, denying octogenarians MVr operations based on age alone should be reconsidered. Depending on risk factors and comorbidities, either SMVr or TMVr is a viable and relatively safe option for octogenarians with severe MR.

Risk score for arch reconstruction under circulatory arrest with hypothermia: The ARCH score.

OBJECTIVE: Currently, there is no risk scores built to predict risk in thoracic aortic surgery. This study aims to develop and internally validate a risk prediction score for patients who require arch reconstruction with hypothermic circulatory arrest. METHODS: From 2002 to 2018, data for 2270 patients who underwent aortic arch surgery in 12 institutions in Canada were retrospectively collected. The outcomes modeled included in-hospital mortality and a modified Society of Thoracic Surgeons-defined composite for mortality or major morbidity. Multivariable logistic regression using least absolute shrinkage and selection operator selection method and mixed-effect regression model was used to select the predictors. Internal calibration of the final models is presented with an observed-versus-predicted plot. RESULTS: There were 182 in-hospital deaths (8.0%), and the incidence of Society of Thoracic Surgeons-defined composite for mortality or major morbidity was 27.9%. Variables that increased risk of mortality are age, chronic obstructive pulmonary disease, atrial fibrillation, peripheral vascular disease, New York Heart Association class ≥III symptoms, acute aortic dissection or rupture, use of elephant trunk, concomitant surgery, and increased cardiopulmonary bypass time, with median c-statistics of 0.85 on internal validation. The c-statistics was 0.77 for the model predicting Society of Thoracic Surgeons-defined composite. Internal assessment shows good overall calibration for both models. CONCLUSIONS: We developed and internally validated a risk score for patients undergoing arch surgery requiring hypothermic circulatory arrest using a multicenter database. Once externally validated, the ARCH (Arch Reconstruction under Circulatory arrest with Hypothermia) score would allow for better patient risk-stratification and aid in the decision-making process for surgeons and patient prior to surgery.