Surveillance Imaging Following Acute Type A Aortic Dissection

Distal aortic progression following acute type A aortic dissection repair among patients with bicuspid and tricuspid aortic valves

OBJECTIVE

The study objective was to analyze long-term growth and outcomes of the distal aorta after open acute type A aortic dissection repair in patients with bicuspid aortic valves or tricuspid aortic valves without connective tissue disease.

METHODS

From 1996 to 2021, 60 patients with bicuspid aortic valves and 655 patients with tricuspid aortic valves without connective tissue disease underwent open repair for acute type A aortic dissection. Data were collected from the local Society of Thoracic Surgeons database, medical record review, surveys, and the National Death Index and Michigan Death Index (December 12, 2021).

RESULTS

Compared with the tricuspid aortic valve group, the bicuspid aortic valve group was significantly younger, had more severe aortic insufficiency (33% vs 22%, P = .05), and had less hypertension (67% vs 78%, P = .05). Intraoperatively, patients with bicuspid aortic valves received more aortic root replacements (70% vs 26%, P < .001), less zone 2 aortic arch replacement (8.3% vs 20%, P = .03), and longer median cardiopulmonary bypass (233 vs 214 minutes, P = .05) and aortic crossclamp (184 vs 141 minutes, P < .001) times. The average annual aortic arch growth rate (0.23 mm/year vs 0.39 mm/year, P = .52) and descending aorta growth rate (0.61 mm/year vs 0.79 mm/year, P = .39) were similar between the bicuspid aortic valve and tricuspid aortic valve groups. The bicuspid aortic valve group had lower annual abdominal aorta growth (0.51 mm/year vs 0.68 mm/year, P = .03). The cumulative incidence of reoperation for the distal aorta (9.7% vs 16.0%, P = .77) was similar between the bicuspid aortic valve and tricuspid aortic valve groups. The 10-year survival was higher in the bicuspid aortic valve group (75.4% vs 66.0%, P = .03).

CONCLUSIONS

Patients with bicuspid aortic valves could be treated similarly as patients with tricuspid aortic valves without connective tissue disease in the setting of open acute type A aortic dissection repair.

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.

Morphologic prognostic factor for thoracoabdominal aortic dilation after acute type A dissection repair

OBJECTIVES

Risk factors for late-term aortic dilation after acute type A aortic dissection repair have not been well examined. The goal of this study was to determine the relationship between the abdominal aortic true lumen location and thoraco-abdominal aortic dilation after surgical repair for acute type A aortic dissection.

METHODS

Patients who were preoperatively diagnosed with acute type A aortic dissection between April 2014 and July 2022 were included in this study. We evaluated the renal artery-level dissected aortic morphology and classified the study population into 2 groups: the ventral (those with the true lumen located on the ventral side) and the dorsal (other patients not assigned to the ventral group) groups, based on the location of the true lumen. Aortic dilation was defined as thoraco-abdominal aortic expansion ≥5 mm on 1-year postoperative computed tomography images.

RESULTS

We examined 49 surgical patients who were assigned to the ventral (n = 22) and dorsal (n = 27) groups. The number of patients with ≥5 mm thoraco-abdominal aortic dilation after the operation was significantly higher in the ventral group than in the dorsal group (90.9% vs 51.9%, P = 0.009). The multivariable logistic regression analysis showed that the ventral type was an independent prognostic factor for thoraco-abdominal aortic dilation after the operation (odds ratio, 6.01; 95% confidence interval, 1.56-23.77; P = 0.009).

CONCLUSIONS

The location of the true lumen of the abdominal aorta in acute type A aortic dissection may be a prognostic factor for thoraco-abdominal aortic dilation after surgical repair.

Reinterventions After Repair of Acute Type A Aortic Dissection: Incidence, Outcomes, and Risk Factors

BACKGROUND

This study reports the incidence, outcomes, and risk factors for aortic reinterventions after repair of acute type A aortic dissection (ATAAD).

METHODS

This was an observational study of aortic operations from 2010 to 2021. All patients with ATAAD undergoing open aortic arch reconstruction were included. Patients were dichotomized by the need for reintervention, which included reinterventions proximal to or distal to the index aortic repair. Propensity matching was used to determine the impact of reintervention on long-term outcomes. The cumulative incidence function for reintervention was estimated, and multivariable Fine-Gray analysis was performed to identify variables associated with reintervention, with death treated as a competing event.

RESULTS

We identified 601 patients undergoing surgery for ATAAD. An aortic reintervention was required in 71 (11.8%), comprising a proximal reintervention in 12 patients, a distal reintervention in 56, and both in 3. The cumulative incidence of reintervention was 11.6% (95% CI, 8.9%-14.6%) at 5 years and was 16.0% (95% CI, 12.2%-20.3%) at 10 years, with a median time to reintervention of 4.0 years (interquartile range, 0.9-7.5 years). Multivariable analysis using the Fine-Gray method showed no operative variables were associated with reinterventions. Among the 71 reinterventions, there were 4 (5.6%) operative deaths. After propensity matching, there was no difference in Kaplan-Meier survival estimates across each group (P = .138 by log-rank statistics).

CONCLUSIONS

The cumulative incidence of aortic reintervention after ATAAD repair was reasonably low (16% at 10 years), reinterventions were relatively safe (6% operative mortality), and reinterventions did not significantly impact long-term survival.

Frozen elephant trunk versus conventional proximal repair of acute aortic dissection type I

Objective

The extent of surgery and the role of the frozen elephant trunk (FET) for surgical repair of acute aortic dissection type I are still subjects of debate. The aim of the study is to evaluate the short- and long-term results of acute surgical repair of aortic dissection type I using the FET compared to standard proximal aortic repair.

Methods

Between October 2009 and December 2016, 172 patients underwent emergent surgery for acute type I aortic dissection at our center. Of these, n = 72 received a FET procedure, while the other 100 patients received a conventional proximal aortic repair. Results were compared between the two surgery groups. The primary endpoints included 30-day rates of mortality and neurologic deficit and follow-up rates of mortality and aortic-related reintervention.

Results

Demographic data were comparable between the groups, except for a higher proportion of men in the FET group (76.4% vs. 60.0%, p = 0.03). The median age was 62 years [IQR (20), p = 0.17], and the median log EuroSCORE was 38.6% [IQR (31.4), p = 0.21]. The mean follow-up time was 68.3 ± 33.8 months. Neither early (FET group 15.3% vs. proximal group 23.0%, p = 0.25) nor late (FET group 26.2% vs. proximal group 23.0%, p = 0.69) mortality showed significant differences between the groups. There were fewer strokes in the FET patients (FET group 2.8% vs. proximal group 11.0%, p = 0.04), and the rates of spinal cord injury were similar between the groups (FET group 4.2% vs. proximal group 2.0%, p = 0.41). Aortic-related reintervention rates did not differ between the groups (FET group 12.1% vs. proximal group 9.8%, p = 0.77).

Conclusion

Emergent FET repair for acute aortic dissection type I is safe and feasible when performed by experienced surgeons. The benefits of the FET procedure in the long term remain unclear. Prolonged follow-up data are needed.

Utility of structured follow-up imaging after aortic surgery

BACKGROUND

Although postoperative follow-up after aortic surgery is recommended by guidelines, its clinical utility is not well documented. We hypothesized that structured follow-up imaging by an aortic program would improve outcomes. We then documented radiologic findings on asymptomatic postoperative imaging.

METHODS

All patients who survived to discharge after open thoracic aortic surgery between January 2017 and July 2021 were included, excluding endocarditis. Patients who followed at our center and received scheduled imaging were compared with patients who did not. Survival was analyzed by the method of Kaplan-Meier, and reintervention was assessed using the Fine-Gray subhazard function. Routine imaging was reviewed for aortic growth, pseudoaneurysm, and perigraft density.

RESULTS

After aortic surgery, the cumulative incidence of follow-up was 38.6% at 3 years postoperatively. Patients with follow-up were more likely to have a dissection and fewer comorbidities but were similar in regards to socioeconomic factors and distance to hospital. After matching and accounting for immortal time bias, patients with follow-up had a greater reintervention rate (26.0% vs 9.0%) with similar survival (98.7% vs 95.2%, P = .110) at 4 years. The cumulative incidence of pseudoaneurysm, significant perigraft density, and growth ≥3 mm/year on routine imaging was 49.7% at 3 years.

CONCLUSIONS

Implementation of structured follow-up imaging by an aortic program resulted in low clinical compliance. Follow-up was associated with increased rates of aortic reintervention. Clinically relevant radiologic findings were common on asymptomatic imaging and increased throughout 5-year follow-up rather than plateauing in the early postoperative period.

Molecular characterization and clinical investigation of patients with heritable thoracic aortic aneurysm and dissection

OBJECTIVES

Thoracic aortic aneurysm and dissection has a genetic predisposition and a variety of clinical manifestations. This study aimed to investigate the clinical and molecular characterizations of patients with thoracic aortic aneurysm and dissection and further explore the relationship between the genotype and phenotype, as well as their postoperative outcomes.

METHODS

A total of 1095 individuals with thoracic aortic aneurysm and dissection admitted to our hospital between 2013 and 2022 were included. Next-generation sequencing and multiplex ligation-dependent probe amplification were performed, and mosaicism analysis was additionally implemented to identify the genetic causes.

RESULTS

A total of 376 causative variants were identified in 83.5% of patients with syndromic thoracic aortic aneurysm and dissection and 18.7% of patients with nonsyndromic thoracic aortic aneurysm and dissection, including 8 copy number variations and 2 mosaic variants. Patients in the "pathogenic" and "variant of uncertain significance" groups had younger ages of aortic events and higher aortic reintervention risks compared with genetically negative cases. In addition, patients with FBN1 haploinsufficiency variants had shorter reintervention-free survival than those with FBN1 dominant negative variants.

CONCLUSIONS

Our data expanded the genetic spectrum of heritable thoracic aortic aneurysm and dissection and indicated that copy number variations and mosaic variants contributed to a small proportion of the disease-causing alterations. Moreover, positive genetic results might have a possible predictive value for aortic event severity and postoperative risk stratification.

The Aortic Team Model and Collaborative Decision Pathways for the Management of Complex Aortic Disease: Clinical Practice Update From the Canadian Cardiovascular Society/Canadian Society of Cardiac Surgeons/Canadian Society for Vascular Surgery/Canadian Association for Interventional Radiology

Disease of the aortic arch, descending thoracic, or thoracoabdominal aorta necessitates dedicated expertise across medical, endovascular, and surgical specialties. Cardiologists, cardiac surgeons, vascular surgeons, interventional radiologists, and others have expertise and skills that aid in the management of patients with complex aortic disease. No specialty is uniformly expert in all aspects of required care. Because of this dispersion of expertise across specialties, an aortic team model approach to decision-making and treatment is advocated. A nonhierarchical partnership across specialties within an interdisciplinary aortic clinic ensures that all treatment options are considered and promotes shared decision-making between the patient and all aortic experts. Furthermore, regionalization of care for aortic disease of increased complexity assures that the breadth of treatment options is available and that favourable volume-outcome ratios for high-risk procedures are maintained. An awareness of best practice care pathways for patient referrals for preventative management, acute care scenarios, chronic care scenarios, and pregnancy might facilitate a more organized management schema for aortic disease across Canada and improve lifelong surveillance initiatives.

Secondary Endovascular Conversions for Failed Open Repair

Late aortic and graft-related complications after open aortic repair are not infrequent and a significant number of them are missed, diagnosed at a very late stage, or present as urgent complications such as aortic rupture or aorto-enteric fistula. Once a late complication is diagnosed and reintervention is necessary, both open and endovascular strategies are possible. Open reintervention is complex and usually associated with very high rates of morbidity and mortality. Endovascular techniques may offer several solutions for these cases, which may be tailored to the patient and specific complication. In this review, we aim to summarize current indications, options, and strategies for endovascular salvage after failed or complicated open surgical repair.

Risk factors for in-hospital death in 2,179 patients with acute aortic dissection

Background

This study aims to investigate the risk factors for in-hospital death in patients with acute aortic dissection (AAD) and to provide a straightforward prediction model to assist clinicians in determining the outcome of AAD patients.

Methods

Retrospective analysis was carried out on 2,179 patients admitted for AAD from March 5, 1999 to April 20, 2018 in Wuhan Union Hospital, China. The risk factors were investigated with univariate and multivariable logistic regression analysis.

Results

The patients were divided into two groups: Group A, 953patients (43.7%) with type A AAD; Group B, 1,226 patients (56.3%) with type B AAD. The overall in-hospital mortality rate was 20.3% (194/953) and 4% (50/1,226) in Group A and B respectively. The multivariable analysis included the variables that were statistically significant predictors of in-hospital death (P < 0.05). In Group A, hypotension (OR = 2.01, P = 0.001) and liver dysfunction (OR = 12.95, P < 0.001) were independent risk factors. Tachycardia (OR = 6.08, P < 0.001) and liver dysfunction (OR = 6.36, P < 0.05) were independent risk factors for Group B mortality. The risk factors of Group A were assigned a score equal to their coefficients, and the score of -0.5 was the best point of the risk prediction model. Based on this analysis, we derived a predictive model to help clinicians determine the prognosis of type A AAD patients.

Conclusions

This study investigate the independent factors associated with in-hospital death in patients with type A or B aortic dissection, respectively. In addition, we develop the prediction of the prognosis for type A patients and assist clinicians in choosing treatment strategies.

Gender differences in acute aortic syndromes

PURPOSE OF REVIEW

Acute aortic syndromes include acute aortic dissection, intramural hematoma, and penetrating aortic ulcer, and are associated with high mortality and morbidity. This review focuses on recent findings and current understanding of gender-related and sex-related differences in acute aortic syndromes.

RECENT FINDINGS

Large international and national registries, population studies, and multicentre national prospective cohort studies show evidence of sex differences in acute aortic syndromes. Recent studies of risk factors, aorta remodelling, and genetics provide possible biological basis for sex differences. The 2022 American College of Cardiology/American Heart Association Guidelines for the Diagnosis and Management of Aortic Disease revise recommendations for surgical management for aortic root and ascending aorta dilatation, which could impact outcome differences between the sexes.

SUMMARY

Acute aortic syndromes affect men more frequently than women. The prevalence of acute aortic syndromes and prevalence of many risk factors rise sharply with age in women leading to higher age at presentation for women. Times from symptom onset to presentation and presentation to diagnosis are delayed in female patients. Females with type A dissection are also more commonly treated conservatively than male counterparts. These factors likely contribute to higher early mortality and complications in women.

Endovascular therapy for Stanford B aortic dissection for patients with Marfan Syndrome: systematic review and meta-analysis

INTRODUCTION

The role of thoracic endovascular aortic repair (TEVAR) in patients with Marfan Syndrome with Stanford type B aortic dissection (TBAD) remains under debate.

EVIDENCE ACQUISITION

MEDLINE and EMBASE were searched through December 2021 to identify studies that investigated outcomes in MFS patients with TBAD who underwent TEVAR. Data regarding patient characteristics, perioperative and late outcomes were extracted.

EVIDENCE SYNTHESIS

Twelve studies were identified including 120 patients. The mean age was 40.2 years (95% confidence interval [CI], 36.8-43.6). 40.4% (95% CI: 10.8-70.0) of cases were performed emergently. 76.2% (95% CI: 64.6-87.8) of patients had a history of previous aortic surgery. In-hospital mortality was 3.7% (95% CI: 0.6-6.8). Primary endoleak occurred in 15.2% (95% CI: 8.6-21.8), which was comprised of type 1 (9.3% [95% CI: 3.9-14.6]) and type 2 (7.1% [95% CI: 2.3-12.0]) endoleaks. During mean follow-up period of 37.4 months (95% CI: 24.1-50.7), secondary endoleak was reported in 14.1% (95% CI: 7.1-21.1), which was comprised of type 1 (7.4% [95% CI: 2.4-12.5]) and type 2 (4.0% [95% CI: 0.3-7.7]) endoleak. Repeat TEVAR was performed in 15.5% (95% CI: 9.3-21.8) and open aortic surgery in 18.6% (95% CI: 9.6-27.5). Long-term mortality was 11.9% (95% CI: 6.5-17.3).

CONCLUSIONS

Our analysis showed that TEVAR for TBAD in patients with MFS has low perioperative morbidity and mortality but was associated with a high rate of late reintervention. This treatment option should be limited to emergent cases and to patients deemed unsuitable for open repair. Lifelong follow-up with imaging is mandatory in this population.

Imaging surveillance for complications after primary surgery for type A aortic dissection

Acute type A aortic dissection (ATAAD) is a life-threatening condition that requires emergency surgery to avert fatal outcome. Conventional surgical procedures comprise excision of the entry tear and replacement of the proximal aorta with a synthetic vascular graft. In patients with DeBakey type I dissection, this approach leaves a chronically dissected distal aorta, putting them at risk for progressive dilatation, dissection propagation and aortic rupture. Therefore, ATAAD survivors should undergo serial imaging for evaluation of the aortic valve, proximal and distal anastomoses, and the aortic segments beyond the distal anastomosis. The current narrative review aims to describe potential complications in the early and late phases after ATAAD surgery, with focus on their specific imaging findings.

Current Understanding of Aortic Dissection

The aorta is the largest artery in the body, delivering oxygenated blood from the left ventricle to all organs. Dissection of the aorta is a lethal condition caused by a tear in the intimal layer of the aorta, followed by blood loss within the aortic wall and separation of the layers to full dissection. The aorta can be affected by a wide range of causes including acute conditions such as trauma and mechanical damage; and genetic conditions such as arterial hypertension, dyslipidaemia, and connective tissue disorders; all increasing the risk of dissection. Both rapid diagnostic recognition and advanced multidisciplinary treatment are critical in managing aortic dissection patients. The treatment depends on the severity and location of the dissection. Open surgical repair is the gold standard of treatment for dissections located to the proximal part of the aorta and the arch, while endovascular interventions are recommended for most distal or type B aortic dissections. In this review article, we examine the epidemiology, pathophysiology, contemporary diagnoses, and management of aortic dissection.

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 1^st, 2000, to May 10^th, 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.

Nationwide database analysis of one-year readmission rates after open surgical or thoracic endovascular repair of Stanford Type B aortic dissection

OBJECTIVE

We examined readmissions and resource use during the first postoperative year in patients who underwent thoracic endovascular aortic repair or open surgical repair of Stanford type B aortic dissection.

METHODS

The Nationwide Readmissions Database (2016-2018) was queried for patients with type B aortic dissection who underwent thoracic endovascular aortic repair or open surgical repair. The primary outcome was readmission during the first postoperative year. Secondary outcomes included 30-day and 90-day readmission rates, in-hospital mortality, length of stay, and cost. A Cox proportional hazards model was used to determine risk factors for readmission.

RESULTS

During the study period, type B aortic dissection repair was performed in 6456 patients, of whom 3517 (54.5%) underwent thoracic endovascular aortic repair and 2939 (45.5%) underwent open surgical repair. Patients undergoing thoracic endovascular aortic repair were older (63 vs 59 years; P < .001) with fewer comorbidities (Elixhauser score of 11 vs 17; P < .001) than patients undergoing open surgical repair. Thoracic endovascular aortic repair was performed electively more often than open surgical repair (29% vs 20%; P < .001). In-hospital mortality was 9% overall and lower in the thoracic endovascular aortic repair cohort than in the open surgical repair cohort (5% vs 13%; P < .001). However, the 90-day readmission rate was comparable between the thoracic endovascular aortic repair and open surgical repair cohorts (28% vs 27%; P = .7). Freedom from readmission for up to 1 year was also similar between cohorts (P = .6). Independent predictors of 1-year readmission included length of stay more than 10 days (P = .005) and Elixhauser comorbidity risk index greater than 4 (P = .033).

CONCLUSIONS

Approximately one-third of all patients with type B aortic dissection were readmitted within 90 days after aortic intervention. Surprisingly, readmission during the first postoperative year was similar in the open surgical repair and thoracic endovascular aortic repair cohorts, despite marked differences in preoperative patient characteristics and interventions.