Faculty Bibliography

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.

Aortic root reconstruction operations have undergone substantial evolution with technical modifications, expanding indications, and the need for increasingly complex decision-making. The purpose of this state-of-the-art review is to detail our approach to contemporary aortic root reconstruction operations. First, we review the evolution of root reconstruction procedures over the years and discuss the approach to the aortic root patient for lifetime management of aneurysm and valvular disease in the modern context of management options. We also discuss state-of-the art technical considerations of valve-sparing root replacement, variations of the Ross operation, aortic valve repair principles and challenges in special populations, and considerations for complication-free coronary button reconstruction. We also discuss root reconstruction in high-risk subpopulations including acute type A aortic dissection, congenital, and reoperative patients. We briefly highlight future directions in transcatheter root replacement as well as the outlook for the next generation of aortic root surgeons.

BACKGROUND:Acute kidney injury (AKI) after repair of type A acute aortic dissection (TAAAD) has been shown to affect both short- and long-term outcomes. This study aimed to validate the impact of postoperative AKI on in-hospital and long-term outcomes in a large population of dissection patients presenting to multinational aortic centers. Additionally, we assessed risk factors for AKI including surgical details. METHODS:Patients undergoing surgical repair for TAAAD enrolled in the International Registry of Acute Aortic Dissection database were evaluated to determine the incidence and risk factors for the development of AKI. RESULTS:A total of 3307 patients were identified. There were 761 (23%) patients with postoperative AKI (AKI group) vs 2546 patients without (77%, non-AKI group). The AKI group had a higher rate of in-hospital mortality (n = 193, 25.4% vs n = 122, 4.8% in the non-AKI group, P < .001). Additional postoperative complications were also more common in the AKI group including postoperative cerebrovascular accident, reexploration for bleeding, and prolonged ventilation. Independent baseline characteristics associated with AKI included a history of hypertension, diabetes, chronic kidney disease, evidence of malperfusion on presentation, distal extent of dissection to abdominal aorta, and longer cardiopulmonary bypass time. Kaplan-Meier survival curves revealed decreased 5-year survival among the AKI group (P < .001). CONCLUSIONS:AKI occurs commonly after TAAAD repair and is associated with a significantly increased risk of operative and long-term mortality. In this large study using the International Registry of Acute Aortic Dissection database, several factors were elucidated that may affect risk of AKI.

BACKGROUND:to investigate the frequency and distribution of new ischemic brain lesions detected by diffusion-weighted imaging on brain magnetic resonance imaging after aortic arch surgery. METHODS:This preplanned secondary analysis of the randomized, controlled ACE (Aortic Surgery Cerebral Protection Evaluation) CardioLink-3 trial compared the safety and efficacy of innominate versus axillary artery cannulation during elective proximal aortic arch surgery. Participants underwent pre and postoperative magnetic resonance imaging. New ischemic lesions were defined as lesions visible on postoperative, but not preoperative diffusion weighted imaging. RESULTS:=0.06) were associated with greater number of lesions. CONCLUSIONS:In patients who underwent elective proximal aortic arch surgery, new ischemic brain lesions were common, and predominantly involved the middle cerebral artery territory or cerebellum. Underlying small vessel disease, lower temperature nadir during surgery, and advanced age were risk factors for perioperative ischemic lesions. REGISTRATION:URL: https://www. CLINICALTRIALS:gov; Unique identifier: NCT02554032.

PURPOSE OF REVIEW:The burden of tricuspid regurgitation (TR) is high in the aging population, almost 4% in the age group over 75 have moderate or more TR. This carries a poor prognosis and an increased incidence of mortality, prolonged hospitalization, and rehospitalization in symptomatic patients with severe TR is observed. Percutaneous tricuspid valve intervention has emerged as a viable therapeutic option, with an increasingly large toolbox of both tricuspid repair and replacement devices. The optimal strategy, timing and patient selection for transcatheter intervention are yet to be determined. This review focuses on the current strengths and limitations of transcatheter tricuspid repair vs. replacement, drawing on lessons learned from surgery. RECENT FINDINGS:Early outcome studies have been published in the last 2 years for many of the new percutaneous tricuspid valve devices. We have summarized these results and compared them to surgical tricuspid valve repair and replacement. We found that surgical data shows a tendency to better outcome with tricuspid valve repair compared to replacement. For transcatheter interventions studies comparing repair and replacement are lacking but both interventions show good procedural success rates and are efficient in reducing the grade of tricuspid regurgitation. SUMMARY:Transcatheter tricuspid valve interventions offer a safe and effective alternative to tricuspid surgery or medical therapy. The decision between valve replacement and repair should be based on patient anatomy, operator experience and device availability until head-to-head comparison of different devices are available.

BACKGROUND:Cerebral protection remains the cornerstone of successful aortic surgery; however, there is no consensus as to the optimal strategy. OBJECTIVE:To compare the safety and efficacy of innominate to axillary artery cannulation for delivering antegrade cerebral protection during proximal aortic arch surgery. METHODS:This randomized controlled trial (The Aortic Surgery Cerebral Protection Evaluation CardioLink-3 Trial, ClinicalTrials.gov Identifier: NCT02554032), conducted across 6 Canadian centers between January 2015 and June 2018, allocated 111 individuals to innominate or axillary artery cannulation. The primary safety outcome was neuroprotection per the appearance of new severe ischemic lesions on the postoperative diffusion-weighted-magnetic resonance imaging. The primary efficacy outcome was the difference in total operative time. Secondary outcomes included 30-day all-cause mortality and postoperative stroke. RESULTS:One hundred two individuals (mean age, 63 ± 11 years) were in the primary safety per-protocol analysis. Baseline characteristics between the groups were similar. New severe ischemic lesions occurred in 19 participants (38.8%) in the axillary versus 18 (34%) in the innominate group (P for noninferiority = .0009). Total operative times were comparable (median, 293 minutes; interquartile range, 222-411 minutes) for axillary versus (298 minutes; interquartile range, 231-368 minutes) for innominate (P for superiority = .47). Stroke/transient ischemic attack occurred in 4 (7.1%) participants in the axillary versus 2 (3.6%) in the innominate group (P = .43). Thirty-day mortality, seizures, delirium, and duration of mechanical ventilation were similar in both groups. CONCLUSIONS:diffusion-weighted magnetic resonance imaging assessments indicate that antegrade cerebral protection with innominate cannulation is safe and affords similar neuroprotection to axillary cannulation during aortic surgery, although the burden of new neurological lesions is high in both groups.

Acute type A aortic dissection is a life-threatening condition that confers significant early perioperative risk but is also associated with late aortic disease progression and the need for reintervention. Recent efforts to improve patient outcomes have focused on improving quality of care and extending treatment in the aortic root and arch to reduce late aortic events. The hybrid arch frozen elephant trunk technique facilitates a more aggressive distal aortic repair that may help mitigate the early and late deleterious effects of persistent false lumen perfusion. However, in the acute and emergency settings, management of the left subclavian artery remains a challenge. We present a step-by-step instructional guide on performing an emergency hybrid arch frozen elephant trunk procedure with emphasis on management of the difficult left subclavian artery. Our case report demonstrates a transthoracic aortoaxillary extra-anatomic bypass of the left axillary artery. We discuss the most important considerations when managing the left subclavian artery in an acute type A aortic dissection. Finally, we detail the benefits and limitations of the transthoracic aortoaxillary extra-anatomic technique and discuss other approaches to left subclavian artery reconstruction.

IMPORTANCE:Early data revealed a mortality rate of 1% to 2% per hour for type A acute aortic dissection (TAAAD) during the initial 48 hours. Despite advances in diagnostic testing and treatment, this mortality rate continues to be cited because of a lack of contemporary data characterizing early mortality and the effect of timely surgery. OBJECTIVE:To examine early mortality rates for patients with TAAAD in the contemporary era. DESIGN, SETTING, AND PARTICIPANTS:This cohort study examined data for patients with TAAAD in the International Registry of Acute Aortic Dissection between 1996 and 2018. Patients were grouped according to the mode of their intended treatment, surgical or medical. EXPOSURE:Surgical treatment. MAIN OUTCOMES AND MEASURES:Mortality was assessed in the initial 48 hours after hospital arrival using Kaplan-Meier curves. In-hospital complications were also evaluated. RESULTS:A total of 5611 patients with TAAAD were identified based on intended treatment: 5131 (91.4%) in the surgical group (3442 [67.1%] male; mean [SD] age, 60.4 [14.1] years) and 480 (8.6%) in the medical group (480 [52.5%] male; mean [SD] age, 70.9 [14.7] years). Reasons for medical management included advanced age (n = 141), comorbidities (n = 281), and patient preference (n = 81). Over the first 48 hours, the mortality for all patients in the study was 5.8%. Among patients who were medically managed, mortality was 0.5% per hour (23.7% at 48 hours). For those whose intended treatment was surgical, 48-hour mortality was 4.4%. In the surgical group, 51 patients (1%) died before the operation. CONCLUSIONS AND RELEVANCE:In this study, the overall mortality rate for TAAAD was 5.8% at 48 hours. For patients in the medical group, TAAAD had a mortality rate of 0.5% per hour (23.7% at 48 hours). However, among those in the surgical group, 48-hour mortality decreased to 4.4%.