Aortic remodelling based on false lumen communications in patients undergoing acute type I dissection repair with AMDS hybrid prosthesis: a substudy of the DARTS trial.

OBJECTIVES: The Dissected Aorta Repair Through Stent (DARTS) Implantation trial demonstrated positive proximal aortic remodelling following aortic dissection repair with the AMDS hybrid prosthesis. In this study, we look to identify predictors of aortic remodelling following aortic dissection repair with AMDS including whether communications between branch vessels and the false lumen (FL) predict aortic growth. METHODS: The DARTS implantation trial included patients who underwent acute DeBakey type I aortic dissection (ATAD I) repair with the AMDS from March 2017 to January 2019. Anatomic measurements were collected from original computerized tomography scans. Measurements were taken at zones 2, 3, 6 and 9. Patients were grouped based on the number of FL communications with the supra-aortic branch vessels or visceral branch vessels. RESULTS: Forty-seven patients were included in the original DARTS implantation trial. Patients with FL communications with the supra-aortic branch vessels tended to have significant growth at zone 3 (P = 0.02-0.0018), while greater numbers of visceral FL communications tended to predict aortic growth at zones 3 (P = 0.003), 6 (P = 0.017-0.0087) and 9 (P = 0.0016-0.0003). CONCLUSIONS: Aortic remodelling following ATAD I repair using the AMDS may be predicted by local FL communications with branch vessels. Patients undergoing ATAD I repair were more likely to experience significant aortic growth in zone 3 with more head vessel communications and in zones 3, 6 and 9 with more visceral FL communications. Predictors of aortic remodelling may help to guide initial surgical management for aortic dissection patients.

Impact of Non-Diameter Aortic Indices on Surgical Eligibility: Results from the TITAN: SvS Randomized Controlled Trial.

OBJECTIVES: Traditional criteria for intervention on an asymptomatic ascending aortic aneurysm has been a maximal aortic diameter of ⩾5.5cm. The 2022 ACC/AHA aortic guidelines adopted cross-sectional aortic area/height ratio, aortic size index (ASI) and aortic height index (AHI) 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 5.0-5.4 cm. METHODS: Patients enrolled from 2018 to 2023 in the randomization or registry arms of the multicenter trial, TITAN: SvS, were included in the study. Clinical data was captured prospectively in an online database. Imaging data were derived from a core CT lab. 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 one of the three criteria (i.e., ASI ⩾ 3.08 cm/m2, AHI ⩾ 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 females compared to males: 20% versus 2% for ASI (p<0.001), 39% versus 5% for AHI (p<0.001) and 39% versus 21% for cross-sectional aortic area/height (p=0.002), respectively. CONCLUSIONS: One third of patients in Titan:SvS would meet criteria for surgical intervention based on novel parameters vs. the classic definition of diameter⩾5.5cm. Surgical thresholds for ASI, AHI or cross-sectional aortic area/height ratio are more likely to be met in female patients compared to male patients.

Decision analysis in cardiac surgery: a scoping review and methodological primer.

OBJECTIVES: Randomized controlled trials are the gold standard for evidence generation in medicine but are limited by their real-world generalizability, resource needs, shorter follow-up durations and inability to be conducted for all clinical questions. Decision analysis (DA) models may simulate trials and observational studies by using existing data and evidence- and expert-informed assumptions and extend analyses over longer time horizons, different study populations and specific scenarios, helping to translate population outcomes to patient-specific clinical and economic outcomes. Here, we present a scoping review and methodological primer on DA for cardiac surgery research. METHODS: A scoping review was performed using the PubMed/MEDLINE, EMBASE and Web of Science databases for cardiac surgery DA studies published until December 2021. Articles were summarized descriptively to quantify trends and ascertain methodological consistency. RESULTS: A total of 184 articles were identified, among which Markov models (N = 92, 50.0%) were the most commonly used models. The most common outcomes were costs (N = 107, 58.2%), quality-adjusted life-years (N = 96, 52.2%) and incremental cost-effectiveness ratios (N = 89, 48.4%). Most (N = 165, 89.7%) articles applied sensitivity analyses, most frequently in the form of deterministic sensitivity analyses (N = 128, 69.6%). Reporting of guidelines to inform the model development and/or reporting was present in 22.3% of articles. CONCLUSION: DA methods are increasing but remain limited and highly variable in cardiac surgery. A methodological primer is presented and may provide researchers with the foundation to start with or improve DA, as well as provide readers and reviewers with the fundamental concepts to review DA studies.

Long-term outcomes following valve-sparing root replacement with concomitant mitral repair.

OBJECTIVES: To examine the late outcomes of valve-sparing root replacement and concomitant mitral valve repair in patients who have been followed prospectively for more than 2 decades. METHODS: From 1992 to 2020, 54 consecutive patients (mean age, 47 ± 16 years; 80% men) underwent valve-sparing root replacement (45 reimplantation and 9 remodeling) with concomitant repair of the mitral valve. Patients were followed prospectively for a median of 9 years (IQR, 3-14 years). RESULTS: No patient experienced perioperative death or stroke. There were 3 late deaths and the 15-year overall survival was 96.0% (95% CI, 74.8%-99.4%), similar to the age- and sex-matched population. Over the follow-up period, 6 patients had reoperation of the aortic valve and 3 on the mitral valve. Of those, 2 had reoperation on both aortic and mitral valves for a total of 7 reoperations in this cohort. The cumulative proportion of reoperation at 10 years of either or both valves were as follows: aortic valve 11.4% (95% CI, 3.9%-33.3%), mitral valve 4.2% (95% CI, 0.6%-28.4%), and both valves 11.4% (95% CI, 3.9%-33.3%). The estimated probability of developing moderate/severe aortic insufficiency at 15 years was 18.5% (95% CI, 9.0%-34.2%). On final echocardiographic follow-up, none of the patients had developed moderate/severe mitral regurgitation. CONCLUSIONS: In this single-center series of concomitant valve-sparing root replacement and mitral valve repair, we observed excellent clinical outcomes with a low risk of death or valve-related complications. Continued surveillance of late valve function is necessary.

Thoracoabdominal Aortic Aneurysm Repair Using Fenestrated and Branched Endovascular Grafts for High-Risk Patients: Evolving yet Safe.

PURPOSE: The purpose was to investigate outcomes of high-risk patients undergoing thoracoabdominal aortic aneurysm (TAAA) repair using fenestrated or branched endovascular aneurysm repair (F/BEVAR) devices at a single center in Canada. MATERIALS AND METHODS: A retrospective review of all patients undergoing endovascular TAAA repair with F/BEVAR from June 2007 to July 2020. Imaging and clinical endpoints of interest including death, reintervention, and target vessel patency were reported. RESULTS: Ninety-five consecutive patients underwent endovascular TAAA repair using F/BEVAR stent grafts (63 males, median age 74 [interquartile range 70, 78] years). Repairs included 81 elective and 14 urgent/emergent cases (6 ruptures and 8 symptomatic). Graft deployment was 100% successful. Intraoperative target vessel revascularization was successful in 336/355 (94.6%) vessels with the celiac having the lowest success rate 72/82 (87.8%). In-hospital mortality was 9.5% (7.4% elective and 21.4% urgent/emergent, p=0.125) and permanent paraplegia was 4.2% (3.7% elective and 7.1% urgent/emergent, p=0.458). In-hospital complications included stroke in 5.3%, acute myocardial infarction in 8.4%, and bowel ischemia in 5.3%. No patients required permanent dialysis or tracheostomy during their hospital stay. However, 22 (23.2%) patients required additional unplanned procedures for various indications (branch occlusion, endoleaks, realignment) during their hospital stay. Patients were followed up for a mean of 3.6 ± 3.0 years. Clinical follow-up was 100%, with 80/86 (93%) having surveillance imaging. On follow-up imaging, 43 (50%) patients had at least 1 endoleak identified and 337/341 (98.8%) of the target vessels were found to be patent. At 5 years, cumulative probability of reintervention was 46.3% (95% confidence interval [CI], 36.1-56.4). Survival at 5 and 8 years was 50.1% (95% CI, 38.4-65.4) and 34.4% (95% CI, 22.5-52.8), respectively. Progression of aneurysmal disease leading to rupture on follow-up was confirmed in 1 patient at 10 years. CONCLUSION: Endovascular TAAA repair provides a safe treatment option with a high technical success rate and low pulmonary and renal complications. Long-term survival is similar to previous literature; however, high rates of secondary reintervention reaffirm the need for ongoing patient follow-up and further technical improvements. CLINICAL IMPACT: This study demonstrates that endovascular repair of TAAAs can be performed in a high-risk elderly population with acceptable rates of mortality, TALE and SCI, using evolving technology. The incidences of post-operative respiratory failure and renal dysfunction were lower in patients who underwent endovascular repair compared with open repair. Future technical and procedural refinements in addition to increasing surgical experience are expected to lead to further improvements in short- and long-term outcomes exceeding those of open repair.

Outcomes of Total Aortic Arch Replacement in a Canadian Nationwide Registry.

BACKGROUND: Accurate benchmarking of outcomes after elective open total arch replacement is important for surgical decision making and for comparisons with emerging endovascular technologies. METHODS: A multicentre registry of consecutive aortic arch procedures in 9 centres across Canada contained 250 elective total arch replacements from 2010 to 2021. A total of 728 patients undergoing elective hemiarch replacement over the same time period was used as a comparator group. Propensity score matching was used to construct 202 well matched pairs. RESULTS: Patients undergoing total arch replacement were 63.2 ± 13.6 years old, and 34% were female. These patients were more likely to have connective tissue disorders compared with patients undergoing hemiarch replacement. When under hypothermic circulatory arrest, the total arch group uniformly used antegrade cerebral perfusion with median nadir temperature of 24°C (interquartile range [IQR] 21-25°C), and median duration 33 minutes (IQR 23-51 minutes). Before matching, in-hospital mortality and stroke rates were 5.2% and 10%, respectively, for the total arch group. After matching, the total arch group had in-hospital mortality similar to the hemiarch group (P = 0.58). Rates of stroke were also not statistically different (P = 0.11). The total arch group was more likely to experience delirium, prolonged intubation, increased intensive care unit length of stay, and transfusions. CONCLUSIONS: Elective total arch replacement is performed with good in-hospital mortality rates that are similar to rates after elective hemiarch repairs. However, total arch replacement was associated with significantly higher rates of other morbidities, including delirium and prolonged intubation.

Risk Prediction Models for Long-Term Survival after Cardiac Surgery: A Systematic Review.

BACKGROUND: The reporting of alternative postoperative measures of quality after cardiac surgery is becoming increasingly important as in-hospital mortality rates continue to decline. This study aims to systematically review and assess risk models designed to predict long-term outcomes after cardiac surgery. METHODS: The MEDLINE and Embase databases were searched for articles published between 1990 and 2020. Studies developing or validating risk prediction models for long-term outcomes after cardiac surgery were included. Data were extracted using checklists for critical appraisal and systematic review of prediction modeling studies. RESULTS: Eleven studies were identified for inclusion in the review, of which nine studies described the development of long-term risk prediction models after cardiac surgery and two were external validation studies. A total of 70 predictors were included across the nine models. The most frequently used predictors were age (n = 9), peripheral vascular disease (n = 8), renal disease (n = 8), and pulmonary disease (n = 8). Despite all models demonstrating acceptable performance on internal validation, only two models underwent external validation, both of which performed poorly. CONCLUSION: Nine risk prediction models predicting long-term mortality after cardiac surgery have been identified in this review. Statistical issues with model development, limited inclusion of outcomes beyond 5 years of follow-up, and a lack of external validation studies means that none of the models identified can be recommended for use in contemporary cardiac surgery. Further work is needed either to successfully externally validate existing models or to develop new models. Newly developed models should aim to use standardized long-term specific reproducible outcome measures.

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.

Hemiarch versus extended arch repair for acute type A dissection: Results from a multicenter national registry.

OBJECTIVE: We compared perioperative outcomes of patients with acute type A aortic dissection undergoing hemiarch (HA) versus extended arch (EA) repair with or without descending aortic intervention. METHODS: Nine hundred twenty-nine patients underwent acute type A aortic dissection repair (2002-2021, 9 centers) including open distal repair (HA) with or without additional EA repair. EA with intervention on the descending aorta (EAD) included elephant trunk, antegrade thoracic endovascular aortic replacement, or uncovered dissection stent. EA with no descending intervention (EAND), included unstented suture-only methods. Primary outcomes were in-hospital mortality, permanent neurologic deficit, computed tomography malperfusion resolution, and a composite. Multivariable logistic regression was also performed. RESULTS: Mean age was 66 ± 18 years, 30% (278 out of 929) were women, and HA was performed more frequently (75% [n = 695]) than EA (25% [n = 234]). EAD techniques included: dissection stent (39 out of 234 [17%]), thoracic endovascular aortic replacement (18 out of 234 [7.7%]), and elephant trunk (87 out of 234 [37%]). In-hospital mortality (EA: n = 49 [21%] and HA: n = 129 [19%]; P = .42), and neurological deficit (EA: n = 43 [18%] and HA: n = 121 [17%]; P = .74) were similar. EA was not independently associated with death (EA vs HA odds ratio, 1.09; 95% CI, 0.77-1.54; P = .63) or neurologic deficit (EA vs HA odds ratio, 0.85; 95% CI, 0.47-1.55; P = .59). Composite adverse events differed significantly (EA vs HA odds ratio, 1.47; 95% CI, 1.16-1.87; P = .001). Malperfusion resolved more frequently after EAD (EAD: n = 32 [80%], EAND: n = 18 [56%], HA: n = 71 [50%]; P = .004), although multivariable analysis was not significant (EAD vs HA odds ratio, 2.17; 95% CI, 0.83-5.66; P = .10). CONCLUSIONS: Extended arch interventions pose similar perioperative mortality and neurologic risks as Hemiarch. Descending aortic reinforcement may promote malperfusion restoration. Extended techniques should be approached with caution in acute dissection due to increased risk of adverse events.

The Call for the "Interventional/Hybrid" Aortic Surgeon: Open, Endovascular, and Hybrid Therapies of the Aortic Arch.

Aortic arch pathology is relatively rare but potentially highly fatal and associated with considerable comorbidity. Operative mortality and complication rates have improved over time but remain high. In response, aortic arch surgery is one of the most rapidly evolving areas of cardiac surgery in terms of surgical volume and improved outcomes. Moreover, there has been a surge in novel devices and techniques, many of which have been developed by or codeveloped with vascular surgeons and interventional radiologists. Nevertheless, the extent of arch surgery, the choice of nadir temperature, cannulation, and perfusion strategies, and the use of open, endovascular, or hybrid options vary according to country, centre, and surgeon. In this review article, we provide a technical overview of the surgical, total endovascular, and hybrid repair options for aortic arch pathology through historical developments and contemporary results. We highlight key information for surgeons, cardiologists, and trainees to understand the management of patients with aortic arch pathology. We conclude by discussing training paradigms, the role of aortic teams, and gaps in knowledge, arguing for the need for wire skills for the future "interventional aortic surgeon" and increased research into techniques and novel devices to continue improving outcomes for aortic arch surgery.

Adjunctive hyperbaric oxygen therapy for spinal cord ischemia after complex aortic repair.

OBJECTIVE: Spinal cord ischemia (SCI) with paraplegia or paraparesis is a devastating complication of complex aortic repair (CAR). Treatment includes cerebrospinal fluid drainage, maintenance of hemoglobin concentration (>10 g/L), and elevating mean arterial blood pressure. Animal and human case series have reported improvements in SCI outcomes with hyperbaric oxygen therapy (HBOT). We reviewed our center's experience with HBOT as a rescue treatment for spinal cord ischemia post-CAR in addition to standard treatment. METHODS: A retrospective review of the University Health Network's Hyperbaric Medicine Unit treatment database identified HBOT sessions for patients with SCI post-CAR between January 2013 and June 2021. Mean estimates of overall motor function scores were determined for postoperative, pre-HBOT, post-HBOT (within 4 hours of the final HBOT session), and at the final assessment (last available in-hospital evaluation) using a linear mixed model. A subgroup analysis compared the mean estimates of overall motor function scores between improvement and non-improvement groups at given timepoints. Improvement of motor function was defined as either a ≥2 point increase in overall muscle function score in patients with paraparesis or an upward change in motor deficit categorization (para/monoplegia, paraparesis, and no deficit). Subgroup analysis was performed by stratifying by improvement or non-improvement of motor function from pre-HBOT to final evaluation. RESULTS: Thirty patients were treated for SCI. Pre-HBOT, the motor deficit categorization was 10 paraplegia, three monoplegia, 16 paraparesis, and one unable to assess. At the final assessment, 14 patients demonstrated variable degrees of motor function improvement; eight patients demonstrated full motor function recovery. Seven of the 10 patients with paraplegia remained paraplegic despite HBOT. The estimated mean of overall muscle function score for pre-HBOT was 16.6 ± 2.9 (95% confidence interval [CI], 10.9-22.3) and for final assessment was 23.4 ± 2.9 (95% CI, 17.7-29.1). The estimated mean difference between pre-HBOT and final assessment overall muscle function score was 6.7 ± 3.1 (95% CI, 0.6-16.1). The estimated mean difference of the overall muscle function score between pre-HBOT and final assessment for the improved group was 16.6 ± 3.5 (95% CI, 7.5-25.7) vs -4.9 ± 4.2 (95% CI, -16.0 to 6.2) for the non-improved group. CONCLUSIONS: HBOT, in addition to standard treatment, may potentially improve recovery in spinal cord function following SCI post-CAR. However, the potential benefits of HBOT are not equally distributed among subgroups.

Trends in sex-specific differences following aortic arch repair: results from the Canadian Thoracic Aortic Collaborative.

Background: Previous data have shown that sex-related differences exist in aortic arch surgery, with female patients experiencing worse outcomes. Over time, as surgical techniques and strategies have improved, these improvements have benefitted female patients. Using a multicenter national aortic registry from the Canadian Thoracic Aortic Collaborative (CTAC), we aimed to determine the relationship between sex and outcomes following aortic arch repair and to examine how these have changed over time. Methods: The multicenter prospective CTAC database of all aortic procedures performed under circulatory arrest from participating centers across Canada (n=9) was used. Patients were included who underwent elective or urgent/emergency arch reconstruction under circulatory arrest from 2002 to 2021. The primary composite endpoint was defined as the occurrence of one of the following endpoints: in-hospital mortality, stroke, dialysis-dependent renal failure, deep sternal wound infection, reoperation, or prolonged ventilation of >40 hours. Secondary endpoints included in-hospital mortality, in-hospital stroke, and a modified version of the Society of Thoracic Surgeons-defined composite endpoint for mortality and major morbidity (MMOM). Results: A total of 2,592 patients who underwent aortic arch repair between 2002 and 2021 (31.4% female and 68.6% male patients). Operative mortality decreased through the study period for female patients. No change in operative mortality was observed in male patients or following elective repair. The composite endpoint improved for female patients over time in both elective and urgent surgery, while for male patients, rates improved for elective surgery and remained stable for urgent. Ultimately, female sex was not an independent predictor of adverse outcomes following aortic arch repair. Conclusions: Our results are congruent with existing data and are highly encouraging. It shows that multilevel improvements in our approach to aortic arch surgery have helped to serve female patients who were previously disadvantaged.

Sex differences in long-term outcomes following surgery for acute type A aortic dissection: a systematic review and meta-analysis.

Background: Recent reports on sex differences in long-term outcomes after surgery for acute type A aortic dissection (ATAAD) are conflicting. We aimed to aggregate updated data on long-term survival and reoperation stratified by sex. Methods: A literature search was conducted using Medline, Embase, and Cochrane Central. Studies reporting sex-stratified long-term survival and/or reoperation following surgery for ATAAD between January 1, 2000, to March 15, 2023 were included. Preoperative characteristics, intraoperative variables, and early perioperative outcomes were meta-analyzed using a random effects model and pooled risk ratio (RR) with men as the reference group. Individual patient-level data for long-term outcomes was reconstructed to generate sex-specific pooled Kaplan-Meier curves to assess long-term survival and freedom from reoperation. Results: A total of 15 studies with 7,608 male and 3,989 female patients were included in this analysis. Female patients were older, had higher rates of hypertension, and had less previous cardiac surgery. Intraoperatively, women received less extensive repairs with lower rates of aortic valve replacement and total arch replacement, and higher rates of hemiarch replacement. There were no sex differences for in-hospital/30-day mortality [risk ratio (RR), 1.18; 95% confidence interval (CI): 0.96, 1.45; P=0.12], stroke (RR, 1.07; 95% CI: 0.90, 1.28; P=0.46), and early reoperation (RR, 0.90; 95% CI: 0.75, 1.09; P=0.28). Female patients had lower long-term survival overall (P<0.001) and amongst survivors at 1-year (P=0.014). Overall survival at 5-year was 82.4% in men and 78.1% in women, and at 10-year was 68.1% for men and 63.4% in women. Male patients had higher rates of long-term reoperation (P<0.001). Freedom for reoperation at 5-year was 88.4% in men vs. 93.1% in women. Conclusions: Though perioperative early outcomes have equalized between the sexes following surgery for ATAAD, differences remain in long-term survival and reoperation.

Barriers to Access to Cardiac Surgery: Canadian Situation and Global Context.

Cardiovascular disease is the leading cause of morbidity and mortality worldwide. Cardiovascular care spans primary, secondary, and tertiary prevention and care, whereby tertiary care is particularly prone to disparities in care. Challenges in access to care especially affect low- and middle-income countries (LMICs), however, multiple barriers also exist and persist across high-income countries. Canada is lauded for its universal health coverage but is faced with health care system challenges and substantial geographic barriers. Canada possesses 203 active cardiac surgeons, or 5.02 per million population, ranging from 3.70 per million in Newfoundland and Labrador to 7.48 in Nova Scotia. As such, Canada possesses fewer cardiac surgeons per million population than the average among high-income countries (7.15 per million), albeit more than the global average (1.64 per million) and far higher than the low-income country average (0.04 per million). In Canada, adult cardiac surgeons are active across 32 cardiac centres, representing 0.79 cardiac centres per million population, which is just above the global average (0.73 per million). In addition to centre and workforce variations, barriers to care exist in the form of waiting times, sociodemographic characteristics, insufficient virtual care infrastructure and electronic health record interoperability, and health care governance fragmentation. Meanwhile, Canada has highly favourable surgical outcomes, well established postacute cardiac care infrastructure, considerable spending on health, robust health administrative data, and effective health technology assessment agencies, which provides a foundation for continued improvements in care. In this narrative review, we describe successes and challenges surrounding access to cardiac surgery in Canada and globally.

Machine learning and decision making in aortic arch repair.

BACKGROUND: Decision making during aortic arch surgery regarding cannulation strategy and nadir temperature are important in reducing risk, and there is a need to determine the best individualized strategy in a data-driven fashion. Using machine learning (ML), we modeled the risk of death or stroke in elective aortic arch surgery based on patient characteristics and intraoperative decisions. METHODS: The study cohort comprised 1323 patients from 9 institutions who underwent an elective aortic arch procedure between 2002 and 2021. A total of 69 variables were used in developing a logistic regression and XGBoost ML model trained for binary classification of mortality and stroke. Shapely additive explanations (SHAP) values were studied to determine the importance of intraoperative decisions. RESULTS: During the study period, 3.9% of patients died and 5.4% experienced stroke. XGBoost (area under the curve [AUC], 0.77 for death, 0.87 for stroke) demonstrated better discrimination than logistic regression (AUC, 0.65 for death, 0.75 for stroke). From SHAP analysis, intraoperative decisions are 3 of the top 20 predictors of death and 6 of the top 20 predictors of stroke. Predictor weights are patient-specific and reflect the patient's preoperative characteristics and other intraoperative decisions. Patient-level simulation also demonstrates the variable contribution of each decision in the context of the other choices that are made. CONCLUSIONS: Using ML, we can more accurately identify patients at risk of death and stroke, as well as the strategy that better reduces the risk of adverse events compared to traditional prediction models. Operative decisions made may be tailored based on a patient's specific characteristics, allowing for maximized, personalized benefit.