Acute Aortic Dissection Research Articles

Diagnosis and management of acute aortic dissection in the emergency department.

Acute aortic dissection is often misdiagnosed as a result of its atypical presentations. It affects 4000 patients a year in the UK of all ages, not just older patients, with increasing numbers of cases expected in the future because of the ageing population. Dissection of the aortic wall leads to sudden, severe pain, and commonly end-organ symptoms which must be recognised. Acute aortic dissection can be challenging to diagnose in the emergency department because of the multitude of possible presentations and the need for selective testing with Computed Tomography Angiography (CTA). Clinicians often miss acute aortic dissection because it is not considered in the differential diagnosis, and the challenge lies in identifying acute aortic dissection in a sea of complaints of chest, back and abdominal pain. There are several ways to improve diagnosis, including awareness campaigns, better education about patients in which to consider acute aortic dissection, and improved detection strategies including which patients should receive CTA. Clinical decision tools and biomarkers could help, but further research is required and is a research focus in emergency medicine. Once diagnosed, blood pressure control, analgesia and urgent surgery or transfer to enable this to occur with minimal delay is required.

Long-term outcomes after recurrent acute thoracic aortic dissection: Insights from the International Registry of Aortic Dissection

ObjectiveWith an aging population and advancements in imaging, recurrence of thoracic aortic dissection is becoming more common. MethodsAll patients enrolled in the International Registry of Aortic Dissection from 1996 to 2023 with type A and type B acute aortic dissection were identified. Among them, initial dissection and recurrent dissection were discerned. The study period was categorized into 3 eras: historic era, 1996 to 2005; middle era, 2006 to 2015; most recent era, 2016 to 2023. Propensity score matching was applied between initial dissection and recurrent dissection. Outcome of interests included long-term survival and cumulative incidence of major aortic events defined by the composite of reintervention, aortic rupture, and new dissection. ResultsThe proportion of recurrent dissection increased from 5.9% in the historic era to 8.0% in the most recent era in the entire dissection cohort. In patients with type A dissection, propensity score matching between initial dissection and recurrent dissection yielded 326 matched pairs. Kaplan–Meier curves showed similar long-term survival between the 2 groups. However, the cumulative incidence of major aortic events was significantly higher in the recurrent dissection group (40.3% ± 6.2% vs 17.8% ± 5.1% at 4 years in the initial dissection group, P = .02). For type B dissection, 316 matched pairs were observed after propensity score matching. Long-term survival and the incidence of major aortic events were equivalent between the 2 groups. ConclusionsThe case volume of recurrent dissection or the ability to detect recurrent dissection has increased over time. Acute type A recurrent dissection was associated with a higher risk of major aortic events than initial dissection. Further judicious follow-up may be crucial after type A recurrent dissection.

α-HBDH is a superior to LDH in predicting major adverse cardiovascular events in patients with acute aortic dissection

ObjectiveAcute aortic dissection (AAD) with a high mortality and postoperative complications remains presently no effective indicators to conjunctly predict the short-term mortality and the prognosis. This study aimed to investigate the predictive role of α-HBDH on in-hospital mortality and postoperative Major adverse cardiovascular events (MACE) in patients with AAD. MethodsIn this retrospective study, a total of 369 enrolled patients from 2015 to 2021 were divided into three groups (T1: low, T2: medium and T3: high) based on the tertiles of α-HBDH levels on admission. In terms of the preoperative, intraoperative and postoperative indicators among 3 groups, the relationship between α-HBDH and studying endpoints was determined by logistic regression models, along with the consolidation using Kaplan–Meier and restricted cubic spline (RCS) analysis for predicting the in-hospital death and MACE complications. Last, subgroup analysis further verified the predictive value of α-HBDH. ResultsLogistic regression analysis showed that α-HBDH was independently associated with in-hospital mortality of patients with AAD [OR(95CI): 4.771(1.043–21.832), P = 0.044] and MACE [OR(95CI): 9.869(2.148–45.349), P = 0.003]. Moreover, Kaplan-Meier analysis also showed an increased α-HBDH levels associated with poor survival within 30 days (log rank test, P < 0.01), especially in acute Stanford A dissection. RCS presented that 204 U/L was the optimal cut-off value of α-HBDH for in-hospital mortality and postoperative MACE, which facilitated clinical stratification of patients with AAD. Subgroup analysis confirmed a stable correlation between α-HBDH level and hospital mortality and MACE (P > 0.05). Conclusionsα-HBDH is a predictor of the in-hospital mortality and postoperative MACE, guiding admission stratification of patients with AAD.

Weekend Effect and Mortality Outcomes in Aortic Dissection: A Prospective Analysis.

Aortic dissection (AD) is a critical heart condition with potentially severe outcomes. Our study aimed to investigate the existence of a "weekend effect" in AD by examining the correlation between patient outcomes and whether their treatment occurred on weekdays versus weekends. Specifically, we prospectively analysed the effect of weekday and weekend treatment on acute AD patient outcomes, both before surgical intervention and during hospitalization, for 124 patients treated from 2019-2021, as well as during 6 months of follow-up. The mean age of the study population was 62.5 years, and patient age exhibited a high degree of variability. We recorded a mortality rate before surgery of 8.65% for the weekend group and 15% for the weekday group, but this difference was not statistically significant. During hospitalization, mortality was 50% in the weekend group and 25% in the weekday group, but this difference was not statistically significant. Discharge mortality was 9.61% in the weekend group and 5% in the weekday group. Our findings suggest that there was no significant difference in mortality rates between patients admitted to the hospital on weekends versus weekdays. Therefore, the period of the week when a patient presents to the hospital with AD appears not to affect their mortality.

Bleeding risk assessment in acute aortic dissection type A using platelet aggregometry

Bleeding risk assessment in acute aortic dissection type A using platelet aggregometry

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

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

Dissection flap fenestration can reduce re-apposition force of the false lumen in type-B aortic dissection: a computational and bench study.

Thoracic endovascular aortic repair (TEVAR) has been widely adopted as a standard for treating complicated acute and high-risk uncomplicated Stanford Type-B aortic dissections. The treatment redirects the blood flow towards the true lumen by covering the proximal dissection tear which promotes sealing of the false lumen. Despite advances in TEVAR, over 30% of Type-B dissection patients require additional interventions. This is primarily due to the presence of a persistent patent false lumen post-TEVAR that could potentially enlarge over time. We propose a novel technique, called slit fenestration pattern creation, which reduces the forces for re-apposition of the dissection flap (i.e., increase the compliance of the flap). We compute the optimal slit fenestration design using a virtual design of experiment (DOE) and demonstrate its effectiveness in reducing the re-apposition forces through computational simulations and benchtop experiments using porcine aortas. The findings suggest this potential therapy can drastically reduce the radial loading required to re-appose a dissected flap against the aortic wall to ensure reconstitution of the aortic wall (remodeling).

Factors associated with in-hospital mortality and morbidity of patients with dissection of aorta type A, undergoing repair surgery

Aim: Acute aortic dissection type A (AADA) is a life-threatening emergency with high mortality rates. Surgical intervention is the preferred and potentially life-saving treatment, but perioperative mortality remains a significant concern. Identifying the risk factors associated with surgical mortality, morbidity, and survival rates is essential. Therefore, this study aimed to characterize the preoperative and intraoperative risk factors for death during surgical repair of AADA. Material and Methods: We included 64 consecutive patients who underwent surgical repair between April 2013 and March 2021 in a tertiary heart center. Perioperative characteristics and variables were collected and analyzed to find any correlation between them and in-hospital Outcomes. Results: Aortic dissection surgery was performed on an average of 8 patients annually, accounting for approximately 1.7% (64/3757) of all open-heart surgery cases. The in-hospital mortality rate was 28% (18/64). The main predisposing factors for in-hospital death were cardiac failure (11.1%), stroke (16.7%), uncontrollable hemorrhage (27.8%), renal failure (11.1%), respiratory failure (11.1%), and postoperative multi-organ failure (22.2%). We found no associations between cardiopulmonary bypass duration and mortality. During the routine use of cerebral protective perfusion, we did not encounter any cases of coma. Left ventricular hypertrophy, a short distance of intimal tear to the aortic valve, and renal failure were associated with postoperative bleeding tendency. Conclusion: Our study showed that multiple factors such as heart failure, uncontrolled bleeding, and respiratory failure increase in-hospital mortality of patients with dissection of aorta type A, but duration of surgery does not have any association with in-hospital death.

Risk factors for long-term mortality after acute aortic dissection-results of the German registry for acute aortic dissection type a long-term follow-up.

Several short-term analyses from German Registry for Acute Aortic Dissection Type A (GERAADA) have been published. This study investigated whether short-term risk factors are transferable to the long-term prognosis of patients. Thirty-three centres with 2686 patients participated in the long-term follow-up. A total of 1164 patients died, 1063 survived and 459 were lost to follow-up during the follow-up timeframe (mean duration: 10.2 years). Long-term mortality of the cohort was compared with an age-stratified, German population. One, 5 and 10 years after initial surgery, the survival of the GERAADA patient cohort was 71.4%, 63.4% and 51%, respectively. Without the early deaths (90-day mortality 25.4%), survival was calculated after 1, 5 and 10 years: 95.6%, 83.5% and 68.3%. Higher age, longer extracorporeal circulation time, shorter perioperative ventilation time and postoperative neurologic deficits were predictive of long-term prognosis. In an age-divided landmark analysis, the mortality of aortic dissection surgery survivors was found to be similar to that of the general German population. If patients are sorted in risk groups according to the GERAADA score, long-term survival differs between the risk groups. If patients have survived an acute postoperative period of 90 days, life expectancy comparable to that of the general German population can be assumed in lower- and medium-risk patients. Whether the GERAADA score can provide valuable insights into the long-term prognosis of patients undergoing surgery for acute aortic dissection type A is still unclear.

Identifying patients with acute aortic dissection using an electrocardiogram with convolutional neural network

BackgroundThe potential of utilizing artificial intelligence with electrocardiography (ECG) for initial screening of aortic dissection (AD) is promising. However, achieving a high positive predictive rate (PPR) remains challenging. Methods and resultsThis retrospective analysis of a single-center, prospective cohort study (Shinken Database 2010–2017, N = 19,170) used digital 12-lead ECGs from initial patient visits. We assessed a convolutional neural network (CNN) model's performance for AD detection with eight-lead (I, II, and V1-6), single-lead, and double-lead (I, II) ECGs via five-fold cross-validation. The mean age was 63.5 ± 12.5 years for the AD group (n = 147) and 58.1 ± 15.7 years for the non-AD group (n = 19,023). The CNN model achieved an area under the curve (AUC) of 0.936 (standard deviation [SD]: 0.023) for AD detection with eight-lead ECGs. In the entire cohort, the PPR was 7 %, with 126 out of 147 AD cases correctly diagnosed (sensitivity 86 %). When applied to patients with D-dimer levels ≥1 μg/dL and a history of hypertension, the PPR increased to 35 %, with 113 AD cases correctly identified (sensitivity 86 %). The single V1 lead displayed the highest diagnostic performance (AUC: 0.933, SD: 0.03), with PPR improvement from 8 % to 38 % within the same population. ConclusionsOur CNN model using ECG data for AD detection achieved an over 30% PPR when applied to patients with elevated D-dimer levels and hypertension history while maintaining sensitivity. A similar level of performance was observed with a single-lead V1 ECG in the CNN model.

Impact of Hospital Integration on Emergency Surgery Patients with Stanford Type A Acute Aortic Dissection

Impact of Hospital Integration on Emergency Surgery Patients with Stanford Type A Acute Aortic Dissection

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

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. 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. 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). 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.

Predictive value of preoperative platelet count and D-dimer levels for spinal cord injury following acute type a aortic dissection.

This study aims to identify the risk factors contributing to spinal cord injury (SCI) following a type A acute aortic dissection (TA-AAD). This retrospective study was conducted at a single center and involved 481 patients who received frozen elephant trunk stent implantation for TA-AAD. Additionally, these patients underwent total arch replacement with deep hypothermic circulatory arrest. This study was performed at Fuwai Hospital between September 2016 and April 2020. The resulting data of the multivariate logistic regression analysis demonstrated that preoperative platelet count (odds ratio [OR] = 0.774) and D-dimer levels (OR = 2.247) could serve as independent predictors for postoperative SCI in patients with TA-AAD. The findings indicate that preoperative platelet count and D-dimer levels are independent risk factors for postoperative SCI in patients with TA-AAD. This study holds significant clinical implications regarding the prognosis and therapeutic responses for patients with TA-AAD.

Prognostic impact of oral anticoagulation therapy and atrial fibrillation in patients with type B acute aortic dissection.

The prognostic impact of atrial fibrillation (AF) and oral anticoagulation (OAC) therapy in patients with type B acute aortic dissection (AAD) remains unclear. Therefore, we investigated the prognostic impact of AF and OAC therapy in patients with type B AAD. Consecutive patients diagnosed with AAD were included in this single-center, retrospective study. Patients with type B AAD were selected from the study population and divided into three groups: AF(+)/OAC(+), AF(+)/OAC(-), and AF(-)/OAC(-). The primary end point was major adverse cardiovascular and cerebrovascular events (MACCE), including all-cause death, progressive aortic events, cerebral infarction, and organ malperfusion. In total, 139 patients diagnosed with type B AAD were analyzed. AF was observed in 27 patients (19%). Among them, 13 patients (9%) received OAC therapy for AF. MACCE occurred in 32 patients (23%) during the observation period: all-cause death in four patients, progressive aortic events in 24 patients, cerebral infarction events in two patients, and malperfusion events in two patients. The incidence of MACCE was higher in the AF(+)/OAC(+) group than in the AF(+)/OAC(-) group (hazard ratio[HR]: 3.875; 95% confidence interval [CI]: 1.153-17.496). In contrast, there was no significant difference in the incidence of MACCE between the AF(+)/OAC(-) and AF(-)/OAC(-) groups (HR: 1.001, 95% CI: 0.509-1.802). Among patients with type B AAD, the use of OAC for AF was associated with a higher risk of MACCE.

Axillary vs Femoral Arterial Cannulation in Acute Type A Dissection: International Multicenter Data

BackgroundCannulation strategy in acute type A dissection (ATAD) varies widely without known gold standards. This study compared ATAD outcomes of axillary vs femoral artery cannulation in a large cohort from the International Registry of Acute Aortic Dissection (IRAD). MethodsThe study retrospectively reviewed 2145 patients from the IRAD Interventional Cohort (1996-2021) who underwent ATAD repair with axillary or femoral cannulation (axillary group: n = 1106 [52%]; femoral group: n = 1039 [48%]). End points included the following: early mortality; neurologic, respiratory, and renal complications; malperfusion; and tamponade. All outcomes are presented as axillary with respect to femoral. ResultsThe proportion of patients younger than 70 years in both groups was similar (n = 1577 [74%]), as were bicuspid aortic valve, Marfan syndrome, and previous dissection. Patients with femoral cannulation had slightly more aortic insufficiency (408 [55%] vs 429 [60%]; P = .058) and coronary involvement (48 [8%] vs 70 [13%]; P = .022]. Patients with axillary cannulation underwent more total aortic arch (156 [15%] vs 106 [11%]; P = .02) and valve-sparing root replacements (220 [22%] vs 112 [12%]; P < .001). More patients with femoral cannulation underwent commissural resuspension (269 [30.9%] vs 324 [35.3%]; P = .05). Valve replacement rates were not different. The mean duration of cardiopulmonary bypass was longer in the femoral group (190 [149-237] minutes vs 196 [159-247] minutes; P = .037). In-hospital mortality was similar between the axillary (n = 165 [15%]) and femoral (n = 149 [14%]) groups (P = .7). Furthermore, there were no differences in stroke, visceral ischemia, tamponade, respiratory insufficiency, coma, or spinal cord ischemia. ConclusionsAxillary cannulation is associated with a more stable ATAD presentation, but it is a more extensive intervention compared with femoral cannulation. Both procedures have equivalent early mortality, stroke, tamponade, and malperfusion outcomes after statistical adjustment.

Thoracic endovascular aortic repair for acute aortic dissection complicated by mesenteric malperfusion: an evaluation by computational fluid dynamics.

Computational fluid dynamics was performed to simulate haemodynamics of type B aortic dissection complicated by mesenteric malperfusion caused by dynamic obstruction in a 70-year-old man. Streamline analysis showed disappearance of antegrade flow in the false lumen of the descending aorta and attenuation of intermittent flap-induced disruption of visceral vessel perfusion after entry coverage. Quantitative analysis showed endovascular repair increased perfusion volume of the coeliac artery and superior mesenteric artery by 55.6% and 77.4%, respectively. Entry closure with thoracic endovascular prosthesis improved mesenteric malperfusion by attenuating the intermittent flap-induced perfusion disruption.

Incidence, presentation and outcome of acute aortic dissection: results from a population-based study

ObjectivesTo describe the incidence of acute aortic dissection in a clearly defined population, to assess onset symptoms and admission biochemical marker levels and to analyse variables potentially associated to mortality.MethodsMedical...

Risk factors for one-year mortality following discharge in patients with acute aortic dissection: development and validation of a predictive model in a cross-sectional study

PurposeThis study was aimed to identify the risk factors that influence the mortality risk in patients with acute aortic dissection (AAD) within one year after discharge, and aimed to construct a predictive model for assessing mortality risk.MethodsThe study involved 320 adult patients obtained from the Medical Information Mart for Intensive Care (MIMIC) database. Logistic regression analysis was conducted to identify potential risk factors associated with mortality in AAD patients within one year after discharge and to develop a predictive model. The performance of the predictive model was assessed using the receiver operating characteristic curve (ROC), calibration curve, and decision curve analysis (DCA). To further validate the findings, patient data from the First Affiliated Hospital of Guangxi Medical University (157 patients) were analyzed.ResultsUnivariate and multivariate logistic regression analyses revealed that gender, length of hospital stay, highest blood urea nitrogen (BUN_max), use of adrenaline, and use of amiodarone were significant risk factors for mortality within one year after discharge (p < 0.05). The constructed model exhibited a consistency index (C-index) and an area under the ROC curve of 0.738. The calibration curve and DCA demonstrated that these indicators had a good degree of agreement and utility. The external validation results of the model also indicated good predictability (AUC = 0.700, p < 0.05).ConclusionThe personalized scoring prediction model constructed by gender, length of hospital stays, BUN_max levels, as well as the use of adrenaline and amiodarone, can effectively identify AAD patients with high mortality risk within one year after discharge.

Should we operate on patients with acute type A aortic dissection who present with cardiopulmonary resuscitation?

Acute aortic dissection type A (AADA) is a life-threatening medical emergency. Emergent surgical repair is the gold standard but mortality remains high. Mortality is even higher in patients who arrive at the hospital in poor condition, especially after cardiopulmonary resuscitation (CPR). This study was designed to analyse the outcome of patients who underwent surgery for AADA and who require preoperative CPR. Between 2000 and 2023, 810 patients underwent emergent surgery for AADA at our centre. Of these, 63 had preoperative CPR. We performed a retrospective analysis with follow-up. Mean age was 64 ± 13 years and 37 (59%) patients were male. Further, 50 (79%) patients had preoperative intubation, and 54 (86%) had pericardial effusion. Twenty-four (38%) patients had out-of-hospital CPR, 19 (30%) required CPR in hospital and 20 (32%) needed CPR in the operating room. Successful CPR with return of spontaneous circulation was achieved in 41 (65%) patients, and 22 (35%) underwent emergent surgery under ongoing CPR. The median time of CPR was 10 (interquartile range 12) min, and the median time from onset of symptoms to start of the operation was 5.5 (interquartile range 4.8) h. The majority of patients underwent ascending aortic replacement with hemiarch repair (n = 37, 59%). Further, 26 (41%) patients underwent full root replacement. Another 15 (24%) patients underwent total arch repair with or without (frozen) elephant trunk repair. Postoperative stroke was present in 8 (13%) patients. The 30-day mortality was 29 (46%). The 30-day mortality of patients with preoperative intubation was not significantly higher (n = 15/28, 54%, P = 0.446). The 1-, 5- and 10-year survival rates of the entire group were 42, 39 and 36%. Early mortality for patients undergoing surgery for AADA with preoperative CPR is extremely high (almost 50%). However, this means that also ∼50% of patients benefit from surgery despite poor preoperative prognosis. Patients with preoperative intubation after CPR and unknown neurological condition should also undergo surgery. Patients who survive the initial operation for AADA have acceptable long-term survival. Emergent surgery should be offered for all patients with AADA regardless of the preoperative condition, even after CPR.

Aortic dilation in adults with repaired tetralogy of Fallot: a single-centre study.

Tetralogy of Fallot is the most prevalent cyanotic CHD. With the advent of advanced surgical methods, the majority of tetralogy of Fallot patients reach adulthood. However, many need re-intervention for the residual anomalies including residual right ventricular outflow obstruction, pulmonary regurgitation, residual ventricular septal defects, and progressive aortic dilatation. Aortic dilation could lead to aortic regurgitation or dissection requiring surgical correction. In the current study, we aimed to determine the prevalence and outcomes of aortic root dilatation in adults with repaired tetralogy of Fallot in our tertiary care centre. In this retrospective study, 730 consecutive patients with history of repaired tetralogy of Fallot were included. Aortic diameter at the level of annulus, the sinus of Valsalva, sinotubular junction, and the ascending aorta as measured by echocardiography were evaluated. Prevalence of outcomes necessitating re-intervention including aortic regurgitation and dissection were recorded. The mean size of annulus, sinus of Valsalva, sinotubular-junction, and ascending aorta in the latest available echocardiography of patients were 2.4+/-0.4 cm, 3.3+/-0.5 cm, 2.9+/-0.5cm, and 3.2+/-0.5cm, respectively. Prevalence of dilatation of sinus of Valsalva, dilation of Ascending aorta, sinotubular-junction, and aortic annulus was 28.7%, 21%, 8.3%, and 1 %, respectively. Five patients had severe aortic regurgitation (0.6%) and underwent surgical repair. One of these patients presented with acute aortic dissection. Aortic dilation is common in tetralogy of Fallot but prevalence of redo surgery for aortic dilation, regurgitation, and adverse events including acute dissection is low.