Sex-Related Differences in Patients Undergoing Thoracic Aortic Surgery.

BACKGROUND: Contemporary outcomes after surgical management of thoracic aortic disease have improved; however, the impact of sex-related differences is poorly understood. METHODS: A total of 1653 patients (498 [30.1%] female) underwent thoracic aortic surgery with hypothermic circulatory arrest between 2002 and 2017 in 10 institutions of the Canadian Thoracic Aortic Collaborative. Outcomes of interest were in-hospital death, stroke, and a modified Society of Thoracic Surgeons-defined composite for mortality or major morbidity (stroke, renal failure, deep sternal wound infection, reoperation, prolonged ventilation). Multivariable logistic regression was used to determine independent predictors of these outcomes. RESULTS: Women were older (mean±SD, 66±13 years versus 61±13 years; P<0.001), with more hypertension and renal failure, but had less coronary disease, less previous cardiac surgery, and higher ejection fraction than men. Rates of aortic dissection were similar between women and men. Rates of hemiarch, and total arch repair were similar between the sexes; however, women underwent less aortic root reconstruction including aortic root replacement, Ross, or valve-sparing root operations (29% versus 45%; P<0.001). Men experienced longer cross-clamp and cardiopulmonary bypass times, but similar durations of circulatory arrest, methods of cerebral perfusion, and nadir temperatures. Women experienced a higher rate of mortality (11% versus 7.4%; P=0.02), stroke (8.8% versus 5.5%; P=0.01), and Society of Thoracic Surgeons-defined composite end point for mortality or major morbidity (31% versus 27%; P=0.04). On multivariable analyses, female sex was an independent predictor of mortality (odds ratio, 1.81; P<0.001), stroke (odds ratio, 1.90; P<0.001), and Society of Thoracic Surgeons-defined composite end point for mortality or major morbidity (odds ratio, 1.40; P<0.001). CONCLUSIONS: Women experience worse outcomes after thoracic aortic surgery with hypothermic circulatory arrest. Further investigation is required to better delineate which measures may reduce sex-related outcome differences after complex aortic surgery.

Levosimendan in Patients with Left Ventricular Dysfunction Undergoing Cardiac Surgery.

BACKGROUND: Levosimendan is an inotropic agent that has been shown in small studies to prevent or treat the low cardiac output syndrome after cardiac surgery. METHODS: In a multicenter, randomized, placebo-controlled, phase 3 trial, we evaluated the efficacy and safety of levosimendan in patients with a left ventricular ejection fraction of 35% or less who were undergoing cardiac surgery with the use of cardiopulmonary bypass. Patients were randomly assigned to receive either intravenous levosimendan (at a dose of 0.2 µg per kilogram of body weight per minute for 1 hour, followed by a dose of 0.1 µg per kilogram per minute for 23 hours) or placebo, with the infusion started before surgery. The two primary end points were a four-component composite of death through day 30, renal-replacement therapy through day 30, perioperative myocardial infarction through day 5, or use of a mechanical cardiac assist device through day 5; and a two-component composite of death through day 30 or use of a mechanical cardiac assist device through day 5. RESULTS: A total of 882 patients underwent randomization, 849 of whom received levosimendan or placebo and were included in the modified intention-to-treat population. The four-component primary end point occurred in 105 of 428 patients (24.5%) assigned to receive levosimendan and in 103 of 421 (24.5%) assigned to receive placebo (adjusted odds ratio, 1.00; 99% confidence interval [CI], 0.66 to 1.54; P=0.98). The two-component primary end point occurred in 56 patients (13.1%) assigned to receive levosimendan and in 48 (11.4%) assigned to receive placebo (adjusted odds ratio, 1.18; 96% CI, 0.76 to 1.82; P=0.45). The rate of adverse events did not differ significantly between the two groups. CONCLUSIONS: Prophylactic levosimendan did not result in a rate of the short-term composite end point of death, renal-replacement therapy, perioperative myocardial infarction, or use of a mechanical cardiac assist device that was lower than the rate with placebo among patients with a reduced left ventricular ejection fraction who were undergoing cardiac surgery with the use of cardiopulmonary bypass. (Funded by Tenax Therapeutics; LEVO-CTS ClinicalTrials.gov number, NCT02025621 .).

Association of Cerebral Oximetry With Brain Ischemic Lesions and Functional Outcomes in Arch Repair.

BACKGROUND: This exploratory analysis of the randomized controlled Aortic Surgery Cerebral Protection Evaluation CardioLink-3 trial sought to determine if cerebral oximetry desaturation during elective proximal arch repair is associated with detrimental postoperative neuroradiologic and neurofunctional outcomes. METHODS: Cerebral oximetry and pre- and postoperative brain magnetic resonance imaging data from 101 participants were analyzed. Oximetry data from the trial allocation groups were compared; the relationships between cerebral oximetry indices and new ischemic cerebral lesions on magnetic resonance imaging and neurologic outcomes were also evaluated. RESULTS: Total cerebral desaturation events (>20% decrease from baseline) on the left (median [interquartile range], 1 [1-3] vs 1.5 [0.5-3] with innominate and axillary cannulation; P = .80) were comparable to those on the right (1 [1-3] vs 1 [0-3]; P = .75) as were the total area under the curve of desaturation (left, P = .61; right, P = .84). Seventy patients had new ischemic lesions, among whom 36 had new severe lesions. Total desaturation events and area under the curve of desaturation were similar in patients with and without new ischemic lesions or severe lesions. The nadir regional cerebral saturation was lower on the left (49% [41-56]) than the right (53% [44-59]); left desaturation episodes were associated with lower postoperative cognitive test scores (P = .004). CONCLUSIONS: The innominate and axillary cannulation techniques for elective proximal arch repair with unilateral antegrade cerebral perfusion were associated with similar occurrences of cerebral oximetry desaturation and neither were associated with new ischemic lesions.

Impact of nondiameter aortic indices on surgical eligibility: Results from the Treatment in Thoracic Aortic Aneurysm: Surgery Versus Surveillance (TITAN: SvS) randomized controlled trial.

OBJECTIVES: Traditional criterion for intervention on an asymptomatic ascending aortic aneurysm has been a maximal aortic diameter of 5.5 cm or more. The 2022 American College of Cardiology/American Heart Association aortic guidelines adopted cross-sectional aortic area/height ratio, aortic size index, and aortic height index as alternate parameters for surgical intervention. The objective of this study was to evaluate the impact of using these newer indices on patient eligibility for surgical intervention in a prospective, multicenter cohort with moderate-sized ascending aortic aneurysms between 5.0 and 5.4 cm. METHODS: Patients enrolled from 2018 to 2023 in the randomization or registry arms of the multicenter trial, Treatment In Thoracic Aortic aNeurysm: Surgery versus Surveillance, were included in the study. Clinical data were captured prospectively in an online database. Imaging data were derived from a core computed laboratory. RESULTS: Among the 329 included patients, 20% were female. Mean age was 65.0 ± 11.6 years, and mean maximal aortic diameter was 50.8 ± 3.9 mm. In the one-third of all patients (n = 109) who met any 1 of the 3 criteria (ie, aortic size index ≥3.08 cm/m2, aortic height index ≥3.21 cm/m, or cross-sectional aortic area/height ≥ 10 cm2/m), their mean maximal aortic diameter was 52.5 ± 0.52 mm. Alternate criteria were most commonly met in women compared with men: 20% versus 2% for aortic size index (P < .001), 39% versus 5% for aortic height index (P < .001), and 39% versus 21% for cross-sectional aortic area/height (P = .002), respectively. CONCLUSIONS: One-third of patients in Treatment In Thoracic Aortic aNeurysm: Surgery versus Surveillance would meet criteria for surgical intervention based on novel parameters versus the classic definition of diameter 5.5 cm or more. Surgical thresholds for aortic size index, aortic height index, or cross-sectional aortic area/height ratio are more likely to be met in female patients compared with male patients.

A prebifurcated axillobifemoral polytetrafluoroethylene graft simplifies carotid to carotid to subclavian bypass.

The use of thoracic endovascular aortic repair for thoracic aortic disease will necessitate cervical debranching in cases involving the proximal arch. We have presented the case of a 57-year-old athletic woman who had developed a type A dissection that extended to the bilateral iliac arteries. After hemiarch repair, she underwent staged cervical debranching with carotid-carotid-subclavian bypass using a prebifurcated axillobifemoral graft and subsequent thoracic endovascular aortic repair. We have detailed her successful clinical course and described the benefits of using a prebifurcated graft for cervical debranching in hybrid repairs of aortic arch pathology.

The Ross procedure in patients older than 50: A sensible proposition?

BACKGROUND: The Ross procedure offers several advantages in nonelderly adults; however, the optimal age cutoff remains undetermined. The aim of this study was to compare the safety and mid-term outcomes after the Ross procedure in adult patients age ≤50 years and those age >50 years. METHODS: Between 2011 and 2019, 497 consecutive patients (mean age, 47 ± 12 years; 73% male) underwent a Ross procedure in 5 Canadian centers and were followed prospectively. Of these patients, 232 (47%) were age >50 years (mean, 57 ± 4 years) and 265 (53%) were age ≤50 years (mean, 38 ± 10 years). Early and mid-term outcomes were compared between the 2 groups. RESULTS: Patients age >50 years had more comorbidities: diabetes (14% vs 4%; P < .01), chronic obstructive pulmonary disease (8% vs 2%; P < .01), and coronary artery disease (17% vs 3%; P < .01). In contrast, patients age ≤50 years had more redo surgeries (24% vs 8%; P < .01), pure aortic regurgitation (21% vs 6%; P < .01) and unicuspid valves (42% vs 9%; P < .01). In-hospital mortality was similar in the 2 groups (0.4% vs 0.4%; P = .99). There were no between-group differences in perioperative complications. The cumulative incidence of reintervention was similar at 6 years (>50 years: 0.7 ± 0.7%; ≤50 years: 4 ± 2%; P = .12). Survival at 6 years was 98 ± 2% in patient age >50 years versus 96 ± 2% in those age ≤50 years (P = .43), similar to the age- and sex-matched general population. CONCLUSIONS: The Ross procedure is a safe operation in patients age >50 years and provides excellent hemodynamics, stable valve function, and restored survival at mid-term follow-up. In expert centers, it should be considered as an alternative in selected patients age >50 years.

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.

A randomized trial comparing axillary versus innominate artery cannulation for aortic arch surgery.

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.

Frozen Elephant Trunk for Aortic Arch Reconstruction is Associated with Reduced Mortality as Compared to Conventional Techniques.

To examine the perioperative outcomes following aortic arch repair using frozen elephant trunk (FET) vs conventional elephant trunk (ET) techniques. Between 2002 and 2018, 390 patients underwent aortic repair with elephant trunk reconstruction at 9 centers: 172 patients received a FET (mean age: 65+/-13 years, 30% female, 37% aortic dissection) and 218 patients received an ET (mean age: 63+/-13 years, 37% female, 43% aortic dissection). Outcomes of interest included in-hospital mortality; stroke; and spinal cord injury (SCI). In-hospital mortality rate was 11% (n = 43) overall, 9% (n = 15) for FET and 13% (n = 28) for ET. Post-operative stroke occurred in 13% (n = 49) overall, 13% (n = 22) for FET and 12% (n = 27) for ET. The rate of post-operative SCI was 3% (n = 13) overall, 5.0% (n = 9) for FET and 2.0% (n = 4) for ET. When compared to ET, the propensity score analysis confirmed FET to be associated with lower mortality (adjusted risk difference -7.0% (95% CI -13.0 to -1.0), P = 0.02). There was no significant difference in the propensity score-adjusted risk difference for stroke between FET and ET (-0.7%, 95% CI -7.4% to 6.1%, P = 0.85), nor for SCI (3.3%, 95% CI -0.4% to 7.0%, P = 0.085) On multivariable analysis, FET was associated with lower odds of mortality (OR 0.44, 95% CI 0.21-0.95, P = 0.04), and had similar odds of stroke (OR 0.83, 95% CI 0.41-1.70, P = 0.62) and SCI (OR 2.83, 95% CI 0.83-9.60, P = 0.1). FET repair is associated with lower in-hospital mortality as compared to conventional ET, and results in similar risk of stroke and spinal cord injury. Further investigation is warranted.

Histological Findings After Aortic Cross-Clamping in Preclinical Animal Models.

Spinal cord ischemic injury and paralysis are devastating complications after open surgical repair of thoracoabdominal aortic aneurysms. Preclinical models have been developed to simulate the clinical paradigm to better understand the neuropathophysiology and develop therapeutic treatment. Neuropathological findings in the preclinical models have not been comprehensively examined before. This systematic review studies the past 40 years of the histological findings after open surgical repair in preclinical models. Our main finding is that damage is predominantly in the grey matter of the spinal cord, although white matter damage in the spinal cord is also reported. Future research needs to examine the neuropathological findings in preclinical models after endovascular repair, a newer type of surgical repair used to treat aortic aneurysms.

The impact of age on patients undergoing aortic arch surgery: Evidence from a multicenter national registry.

OBJECTIVE: Elderly patients are typically offered aortic surgery at similar diameter thresholds as younger patients, despite limited data quantifying their operative risk. We aim to report the incremental risk experienced by elderly patients undergoing aortic arch surgery. METHODS: In total, 2520 patients underwent aortic arch surgery between 2002 and 2018 in 10 centers. Patients were divided into 3 groups: <65 years (n = 1325), 65 to 74 years (n = 737), and ≥75 years (n = 458). Outcomes of interest were in-hospital mortality, stroke, and the modified Society of Thoracic Surgeons composite for mortality or major morbidity (STS-COMP). Multivariable modeling was performed to determine the association of age with these outcomes. RESULTS: As age increased, there was an increasing rate of comorbidities, including diabetes (P < .001), renal failure (P < .001), and previous stroke (P = .01). Rates of acute aortic syndrome (P = .50) and total arch repair were similar (P = .59) between groups. Older patients had greater mortality (<65: 6.1% vs 65-74: 9.0% vs ≥75: 14%, P < .001), stroke (6.3% vs 7.7% vs 11%, P = .01) and STS-COMP (25% vs 32% vs 38%, P < .001). After multivariable risk-adjustment, a step-wise increase in complications was observed in the older age groups relative to the youngest in terms of in-hospital mortality (65-74: odds ratio [OR] 1.57, P = .04; ≥75: OR, 2.94, P = .001) and STS-COMP (65-74: OR, 1.57, P < .001; ≥75: OR, 1.96, P < .001). CONCLUSIONS: Older patients experienced elevated rates of mortality and morbidity following aortic arch surgery. These results support a more measured approach when evaluating elderly patients. Further research is needed on age-dependent natural history of thoracic aneurysms and size thresholds for intervention.

Evolving Surgical Techniques and Improving Outcomes for Aortic Arch Surgery in Canada.

BACKGROUND: To explore evolving surgical techniques and outcomes for aortic arch surgery. METHODS: A total of 2435 consecutive patients underwent aortic arch repair with hypothermic circulatory arrest between 2008 and 2018 in 12 institutions across Canada. Trends in patient characteristics, surgical techniques, and in-hospital outcomes, including major morbidity or mortality, were examined. RESULTS: From 2008 to 2018, the age of patients (62.3 ± 13.2 years) and the proportion of women (30.2%) undergoing arch surgery did not change significantly. Aortic diameters at operation decreased (2008: 58 ± 13 mm; 2018: 53 ± 11 mm; P < 0.01). Surgeons performed more valve-sparing root replacements (2008: 0%; 2018: 15%; P < 0.001) and fewer Bentall procedures (2008: 27%; 2018: 20%; P < 0.01). Total arch replacement rates were similar (P = 0.18); however, elephant trunk (2008: 9.5%; 2018: 19%; P < 0.001) and frozen elephant trunk (2008: 3.1%; 2018: 15%; P < 0.001) repair rates have increased. Over time, higher nadir temperatures (2008: 18 [17-21]°C; 2018: 25 [23-28]°C; P < 0.001), and more frequent antegrade cerebral perfusion (2008: 61%; 2018: 83%; P < 0.001) were used. For elective cases, in-hospital mortality rates declined (2008: 6.8%; 2018: 1.2%; P = < 0.01), as did major morbidity or mortality (2008: 24%; 2018: 13%; P < 0.001) and transfusion rates (2008: 61%; 2018: 41%; P < 0.001), but stroke rates remained constant (2008: 6.8%; 2018: 5.3%; P = 0.12). Outcomes remained the same over time for urgent or emergent cases. CONCLUSIONS: Outcomes have improved over the past decade in Canada for elective aortic arch surgery, in the context of operating on smaller aortas, and more frequent use of moderate hypothermia and antegrade cerebral perfusion. Further research is needed to improve stroke rates and outcomes in the emergency setting.

INTRODUCTION: Examiner l'évolution des techniques chirurgicales et les résultats de l'intervention chirurgicale de l'arc aortique. MÉTHODES: Un total de 2 435 patients consécutifs ont subi une réparation de l'arc aortique en arrêt circulatoire en hypothermie entre 2008 et 2018 dans 12 établissements du Canada. Nous avons examiné les tendances en ce qui concerne les caractéristiques des patients, les techniques chirurgicales et les résultats cliniques intrahospitaliers, y compris les principales causes de morbidité ou de mortalité. RÉSULTATS: De 2008 à 2018, l'âge des patients (62,3 ± 13,2 ans) et la proportion de femmes (30,2 %) subissant l'intervention chirurgicale de l'arc n'a pas montré de changement significatif. Les diamètres aortiques à l'opération ont diminué (2008 : 58 ± 13 mm; 2018 : 53 ± 11 mm; P < 0,01). Les chirurgiens ont réalisé un plus grand nombre de remplacements de la racine aortique sans remplacement de la valve (2008 : 0 %; 2018 : 15 %; P < 0,001) et un moins grand nombre d'opérations de Bentall (2008 : 27 %; 2018 : 20 %; P < 0,01). Les taux totaux de remplacements de l'arc étaient similaires (P = 0,18). Toutefois, les taux de réparation avec la technique de la trompe d'éléphant; (2008 : 9,5 %; 2018 : 19 %; P < 0,001) et de la trompe d'éléphant congelée (2008 : 3,1 %; 2018 : 15 %; P < 0,001) ont augmenté. Avec le temps, des nadirs supérieurs de température (2008 : 18 [17-21]°C; 2018 : 25 [23-28]°C; P < 0,001) et des perfusions cérébrales antérogrades plus fréquentes (2008 : 61 %; 2018 : 83 %; P < 0,001) ont été utilisés. Pour les cas non urgents, les taux de mortalité intrahospitalière (2008 : 6,8 %; 2018 : 1,2 %; P = < 0,01) et les taux de morbidité grave et de mortalité (2008 : 24 %; 2018 : 13 %; P < 0,001) et de transfusion (2008 : 61 %; 2018 : 41 %; P < 0,001) ont décru, mais les taux d'accidents vasculaires cérébraux (2008 : 6,8 %; 2018 : 5,3 %; P = 0,12) sont demeurés constants. Les résultats cliniques sont demeurés identiques au fil du temps pour les cas urgents ou les nouveaux cas. CONCLUSIONS: Au Canada, les résultats de l'intervention chirurgicale non urgente de l'arc aortique se sont améliorés au cours de la dernière décennie dans le contexte de l'opération d'aortes plus petites et de l'utilisation plus fréquente de l'hypothermie modérée et de la perfusion cérébrale antérograde. D'autres recherches sont nécessaires pour améliorer les taux d'accidents vasculaires cérébraux et les résultats cliniques dans le cadre d'interventions urgentes.

Does adding an aortic root replacement or sinus repair during arch repair increase postoperative mortality? Evidence from the Canadian Thoracic Aortic Collaborative.

OBJECTIVES: The aim of this study was to examine the effect of the addition of an aortic root replacement or sinus repair on mortality and morbidity during aortic arch repair. METHODS: A total of 2472 patients underwent proximal or total aortic arch repair with hypothermic circulatory arrest between 2002 and 2018 at 12 centres. Multivariable logistic regressions (MV) and propensity score (PS) with inverse probability of treatment weighting (IPTW) analyses were performed. RESULTS: A total of 1099 (44.5%) patients had additional aortic root replacement (n = 934) or sinus repair (n = 165). Those with aortic root interventions were younger (61 ± 13 vs 64 ± 13 years, P < 0.001) and had less females (23% vs 35%, P < 0.001), less dissection (31% vs 36%, P = 0.004), less urgent cases (35% vs 39%, P = 0.047), more connective tissue disease (7% vs 3%, P < 0.001) and less total arch replacements (14% vs 22%, P < 0.001). On adjusted analyses, the addition of aortic root procedure was associated with increased mortality [MV: odds ratio (OR) 1.41, 95% confidence interval (CI) 1.03-1.92; PS-IPTW: risk increased by 3.7%, 95% CI 1.2-6.3%, P = 0.004]. Reoperation for bleeding was also increased with the addition of aortic root intervention (MV: OR 1.48, 95% 1.10-1.99; PS-IPTW: risk increased by 3.2%, 95% CI 0.8-5.6%, P = 0.009). The risks of stroke and dialysis-dependent renal failure were similar. When looking only at non-elective cases, the increased risk of mortality was more pronounced (MV: OR 1.60, 95% CI 1.11-2.32, P = 0.013; PS-IPTW: risk increased by 6.8%, 95 CI 1.7-11.8%, P = 0.008, and a number need to harm of 15 patients to cause 1 additional death). CONCLUSIONS: The addition of aortic root replacement or sinus repair during proximal or total aortic arch repair seems to increase postoperative mortality only in non-elective cases.

Hybrid arch frozen elephant trunk repair: evidence from the Canadian Thoracic Aortic Collaborative.

BACKGROUND: The frozen elephant trunk (FET) technique has become an increasingly popular strategy for aortic reconstruction in the setting of extensive thoracic aortic aneurysms or dissections. The objective of this study is to report on the Canadian experience with the FET technique in both the elective and emergent settings. METHODS: A total of 167 consecutive patients (mean age 65±13 years, 30% female, 25% re-operation) underwent elective (70%) and non-elective (30%) aortic arch reconstruction with the FET technique between May 2008 and October 2019 in six centers of the Canadian Thoracic Aortic Collaborative (CTAC). In-hospital clinical endpoints and early imaging endpoints were prospectively collected and analyzed. RESULTS: All 167 patients underwent successful FET implantation. In-hospital mortality occurred in 14 patients (8%), stroke occurred in 22 patients (13%) and temporary and permanent spinal cord ischemia (SCI) occurred in 6 (3.6%) and 3 (1.8%) patients, respectively. Prolonged mechanical ventilation was required in 35 patients (21%), renal failure requiring dialysis in 14 patients (8%) and atrial fibrillation in 59 patients (36%). The median hospital and intensive care unit (ICU) lengths of stay were 3 [interquartile range (IQR): 1, 6] and 10 (IQR: 7, 17) days, respectively. The rate of type 1A endoleak was 3.6%, with the lowest rate in patients who underwent a total arch replacement with a hybrid FET graft (0%) and the highest among patients who had a hemiarch with antegrade thoracic endovascular aortic repair (TEVAR) deployment (25%). The rate of other types of endoleak and stent complications was comparatively low. CONCLUSIONS: The early CTAC experience with the FET operation demonstrates technical feasibility and good early clinical outcomes in elective and emergent patients. Further analysis is required to explore variations in technique and their potential impact on early and late outcomes.

Impact of brain protection strategies on mortality and stroke in patients undergoing aortic arch repair with hypothermic circulatory arrest: evidence from the Canadian Thoracic Aortic Collaborative.

OBJECTIVES: The aim of this study was to investigate the impact of various brain perfusion techniques and nadir temperature cooling strategies on outcomes after aortic arch repair in a contemporary, multicentre cohort. METHODS: A total of 2520 patients underwent aortic arch repair with hypothermic circulatory arrest (HCA) between 2002 and 2018 in 11 centres of the Canadian Thoracic Aortic Collaborative. Primary outcomes included mortality; stroke; a composite of mortality or stroke; and a Society of Thoracic Surgeons-defined composite (STS-COMP) end point for mortality or major morbidity including stroke, reoperation, renal failure, prolonged ventilation and deep sternal wound infection. Multivariable logistic regression and propensity score matching were performed for cerebral perfusion and nadir temperature practices. RESULTS: Antegrade cerebral perfusion was found on multivariable analysis to be protective against mortality [odds ratio (OR) 0.64, 95% confidence interval (CI) 0.48-0.86; P = 0.005], stroke (OR 0.55, 95% CI 0.37-0.81; P = 0.006), composite of mortality or stroke (OR 0.57, 95% CI 0.45-0.72; P = 0.0001) and STS-COMP (OR 0.53, 95% CI 0.41-0.67; P < 0.0001), as compared to HCA alone. Retrograde cerebral perfusion yielded similar outcomes as compared to antegrade cerebral perfusion. When compared to HCA with nadir temperature <24°C, a propensity score analysis of 647 matched pairs identified nadir temperature ≥24°C as predictor of lower mortality (OR 0.62, 95% CI 0.40-0.98; P = 0.04), stroke (OR 0.51, 95% CI 0.31-0.84; P = 0.008), composite of mortality or stroke (OR 0.62, 95% CI 0.43-0.89; P = 0.01) and STS-COMP (OR 0.64, 95% CI 0.49-0.85; P = 0.002). CONCLUSIONS: Antegrade cerebral perfusion and nadir temperature ≥24°C during HCA for aortic arch repair are predictors of improved survival and neurological outcomes.

Developing skills for thoracic aortic surgery with hypothermic circulatory arrest.

OBJECTIVES: To examine the performance curves of 8 early-career aortic surgeons with the use of hypothermic circulatory arrest (HCA) and to analyze the impact of the learning curve on perioperative outcomes. METHODS: A total of 1025 consecutive patients who underwent aortic reconstruction with HCA between 2002 and 2017 were analyzed for mortality and 5 other complications (stroke, reoperation for bleeding, dialysis, prolonged ventilation, and sternal wound complications), subdivided into 3 consecutive time periods. This cohort represents the complete inaugural experience of 8 Canadian academic aortic surgeons. A risk-adjusted cumulative sum analysis was used to evaluate the performance curve with respect to predetermined 80% alert and 95% alarm boundary lines. RESULTS: Mean age was 62 ± 13 years, 71% of patients were male, and 24% presented nonelectively. Hemiarch repair was performed in 80% and total arch replacement in 20%. There was a reduction in the incidence of the primary composite outcome over time (P1: 26%, P2: 23%, and P3: 16%; P = .010). Overall in-hospital mortality was 5% and remained stable throughout the 3 periods. Rates of stroke were lower in the late period (P1: 4%, P2: 6%, and P3: 2%; P = .035). Risk-adjusted cumulative sum analysis demonstrated that all surgeons remained within the 95% reassurance boundary throughout their experience, with 6 surgeons performing as expected and 2 performing better than expected. CONCLUSIONS: Early-career surgeons can safely perform operations with HCA from the initiation of their practice. The cumulative sum analysis method is valuable for monitoring competence in aortic surgery and could prove useful in structuring training programs.

Management of the difficult left subclavian artery during aortic arch repair.

Management of the left subclavian artery (SCA) during aortic arch surgery is associated with several challenges, including preserving distal perfusion, achieving hemostasis and preventing posterior circulation stroke and spinal cord injury. The most common challenge remains its deep position in the chest, often exacerbated by posterior and apical displacement from an arch aneurysm. We discuss several management options consisting of pre-, intra- and post-operative strategies and their respective advantages, disadvantages and clinical outcomes. A clinical algorithm is proposed to help guide decision-making in managing the difficult left SCA during aortic arch repair.