Anomalous origin of one pulmonary artery (AOPA) is a rare congenital heart disease whose symptoms often occur in infancy, and patients have little chance of surviving into adulthood without timely treatments. AOPA is more frequent in infants and toddlers rather than in adults, and it accounts for only 0.12% of all congenital heart disease cases. In all AOPA cases, the right pulmonary artery from the ascending aorta remains common. This study reported a case with anomalous origin of the left pulmonary artery (AOLPA) from the descending aorta in a teenager who underwent double-incision surgery of median sternotomy and left lateral thoracotomies with favorable outcomes.

Background The optimal arterial cannulation site for acute aortic dissection repair is unclear, especially for complex arch surgery. Axillary artery cannulation is widely accepted but adding femoral artery cannulation to it was considered to potentially improve perfusion and early outcomes. To clarify this point, a comparison of perioperative outcomes for these two different cannulation strategies was conducted regarding the pathological features of dissection. Methods From January 2010 to December 2019, 927 consecutive patients underwent a total arch replacement combined with frozen elephant trunk for acute type A aortic dissection. The data, including detailed pathological features, were retrospectively collected and analyzed. Propensity score matching and multivariate logistic regression analysis were used for adjusting confounders that are potentially related to the outcome. Results A total of 523 patients (56.3%) accepted a dual arterial cannulation (DAC group), and 406 patients (43.7%) received a single axillary artery cannulation (SAC group). In total, 388 pairs of patients were well-matched. Whether before or after adjusting the preoperative characteristics by matching, there were no significant differences in operative mortality (6.7 vs. 5.4%, P = 0.420 before matching; 5.4 vs. 5.4%, P = 1 after matching), stroke (6.7 vs. 5.4%, P = 0.420 before matching; 6.4 vs. 5.2%, P = 0.435 after matching), spinal cord injury (5 vs. 5.7%, P = 0.640 before matching; 5.4 vs. 5.7%, P = 1. After matching), and acute renal failure requiring dialysis (13.8 vs. 9.6%, P =0.050 before matching; 12.6 vs. 9.5%, P = 0.174) between the two groups. Dual arterial cannulation was not an independent protective factor of operative mortality (odds ratio [OR] 1.01, 95% confidence interval [CI] 0.55–1.86), stroke (OR 1.17, 95% CI 0.65–2.11), spinal cord injury (OR 1.17, 95% CI 0.65–2.11), and acute renal failure requiring continuous renal replacement therapy (CRRT) (OR 1.24, 95% CI 0.78–1.97) after adjusting for confounding factors by multivariable logistic regression analysis. In the subgroup analysis, no advantage of dual arterial cannulation was found for a particular population. Conclusions Single axillary artery cannulation was competent in the complex arch repair for acute aortic dissection, presenting with a satisfactory result as dual arterial cannulation. Adding femoral artery cannulation was necessary when a sufficient flow volume could not be achieved by axillary artery cannulation or when a lower limb malperfusion existed.

Background To compare outcomes between sinus replacement (SR) and conservative repair (CR) for dissected roots with normal size. Methods From October 2018 to April 2021, a prospective cohort study was carried out. Patients were assigned to two groups (SR group and CR group) according to whether they underwent sinus replacement. Propensity score matching was applied to adjust preoperative variables and Kaplan–Meier method was used for survival analysis. Results Three hundred and eighty-seven patients were enrolled. In the whole cohort, 18 patients (4.7%) died postoperatively. The operative mortality of SR group was comparable to CR group (3.2% vs. 6.0%, p = 0.192 before matching; 3.5% vs. 7.0%, p = 0.267 after matching) and the incidence of hemostasis management under restarted cardiopulmonary bypass for root bleeding was lower in SR group (1.6% vs. 7.0%, p = 0.002 before matching; 2.1% vs. 8.5%, p = 0.03 after matching). The median follow-up duration was 12 months. There were 3 reoperations in the CR group. The estimated cumulative event rate of reoperation was 1.1 % at 12 months and 1.6% at 24 months in CR group, with a trend of a lower rate in the SR group (log-rank p = 0.089 before matching, p = 0.075 after matching). There was one late death in each group. The estimated cumulative event rate of death was 3.8% at 12 months and 24 months in the SR group, and was 6.6% in the CR group with no significant difference (log-rank p = 0.218 before matching, p = 0.120 after matching). Aortic regurgitation significantly improved postoperatively and remained stable during follow-up. Conclusions Sinus replacement is a simple, safe, and effective technique for repairing severely dissected sinus with a comparable time spent in operation and excellent immediate and short-term results. It had the advantages of eliminating false lumen and avoiding aortic root bleeding.

Background There are limited data regarding the clinical outcomes of reoperative aortic root or ascending aorta replacement after prior aortic valve replacement (AVR). We aimed to analyze outcomes of reoperative aortic root or ascending aorta replacement after prior AVR. Methods Eighty patients with prior AVR underwent reoperative aortic root or ascending aorta replacement in our hospital. The indications were root or ascending aortic aneurysm in 36 patients, root or ascending aortic dissection in 37, root false aneurysm in 2, prosthesis valve endocarditis (PVE) with root abscess in 2, Behçet’s disease (BD) with root destruction in 3 patients. An elective surgery was performed in 63 patients and an emergent surgery in 17. The survival and freedom from aortic events during the follow-up were evaluated with the Kaplan-Meier survival curve and the log-rank test. Results The operative techniques included ascending aorta replacement in 14 patients, ascending aorta replacement with AVR in 3, prosthesis-sparing root replacement (PSRR) in 35, Bentall procedure in 24, and Cabrol procedure in 4 patients. Operative mortality was 1.3% (1/80). A composite of adverse events occurred in 5 patients, including 1 operative death, 2 stroke and 3 renal failure necessitating hemodialysis. The mean follow-up was 35.5±22.1 months. Five late deaths occurred. The Kaplan-Meier survival at 1 year, 3 years and 6 years were 97.5%, 91.1% and 84.1%, respectively. Aortic events developed in 3 patients. The freedom from aortic events at 1-year, 3-year, and 6-year were 100%, 96.3% and 88.9%, respectively. There were no differences in survival and freedom from aortic events between the elective group and the emergent group. Conclusions Reoperative aortic root or ascending aorta replacement after prior AVR could be performed to treat the root or ascending pathologies after AVR, with satisfactory early and midterm outcomes.

Objective: Isolated true subclavian arter y aneur ysm (SAA) without aberrant subclavian artery or coarctation of descending aorta is a rare peripheral aneurysm. Herein, the experience of our medical center in the treatment of this disease is presented. Methods: The Division operative log was queried to identify cases of SAA repair between January 2012 and September 2019 that were not associated with coarctation of the aorta or the presence of an aberrant subclavian artery. A total of 22 cases were identified. The characteristics, treatment and clinical outcomes of these cases were assessed. Results: The mean age of patients was 53.5 +/- 14.3 years and 14 patients were male (63.6%). Half of the cases were attributed to atherosclerotic degeneration. The clinical symptoms of aneurysms were varied, including asymptomatic, pulsatile mass of supraclavicular fossa, local pain, upper limb embolism, Horner's syndrome and hoarseness. Aneurysms were located on the right in 17 cases, on the left in 3 cases and on both sides in 2 cases. Fifteen (68%) patients underwent an intervention, of which 11 (50%) underwent an open surgical repair, and 4 (18%) underwent endovascular repair. The mean diameter of the aneurysms was 39.5 +/- 20.7 mm in the open surgery group, and 24.0 +/- 4.7 mm in the endovascular group. The follow-up duration ranged from 2 months to 12 years. One patient died of cardiogenic disease in the untreated group. Patients undergoing open operative repair had 100% patency of the reconstruction. In the endovascular group, one patient had stent occlusion 2 years after the operation. Conclusions: The most common cause of isolated subclavian aneurysm without aberrant subclavian artery or coarctation of descending aorta is atherosclerosis. The clinical symptoms of aneurysms are varied, and the aneurysms tend to occur on the right side. Based on the anatomical conditions of SAAs, open surgery and endovascular repair can be used for treatment.

目的 探索主动脉窦成形在修复急性StanfordA型主动脉夹层受累根部中的可行性、有效性和效果的持久性.方法 从2014年1月至2017年7月,共43例急性StanfordA型主动脉夹层患者在我院接受了主动脉窦成形术修复受累的主动脉根部,其中男34例、女9例,年龄32～65(50.1±8.1)岁.回顾性分析患者的围术期和随访资料,对术前、术后和随访时的超声指标进行统计分析.结果 全部患者30 d死亡率为4.7％(2例),5例患者行连续性肾脏替代治疗,1例患者因出血行再次开胸手术.无患者因脆弱的主动脉根部组织出血而接受再次手术.所有患者术前的主动脉瓣反流在术后即刻得以纠正,假腔同时被完全消除.随访时间为18～45 (27.9±6.7)个月,随访期间无远期死亡,2例失访.接受随访的39例患者中,无主动脉根部及主动脉瓣的再次干预,未发现根部存在残余夹层,无显著的根部扩张.比较出院时和随访时的主动脉根部直径和主动脉瓣反流程度,差异无统计学意义.结论 修复在急性Stanford A型主动脉夹层中严重受累的主动脉根部,主动脉窦成形术是一种简便可靠的方法,近期效果优异.

Objective:To evaluate the safety and efficacy of balloon occlusion technique combined with total arch replacement and frozen elephant trunk in the treatment of complex aortic arch diseases.Methods:The clinical data of 100 patients undergoing balloon occlusion technique combined with total arch replacement and frozen elephant trunk surgery in Fuwai Hospital from August 2017 to September 2018 were retrospectively reviewed, and the early clinical results were analyzed.Results:The average circulatory arrest time was(5.2±3.1) min. The lowest nasopharyngeal and bladder temperature was(27.9±1.0) ℃ and(29.2±1.2) ℃, respectively. One patient died in hospital due to multiple organ failure caused by acute liver failure, and a total of 4 patients died within 30 days. Other postoperative complications included cerebral infarction in 3 cases, paraplegia in 2 cases, low cardiac output syndrome requiring IABP assistance in 1 case, renal failure requiring continuous dialysis in 5 cases, redo for bleeding in 4 cases, reintubation in 3 cases, recurrent laryngeal nerve injury in 1 case, and osteofascial compartment syndrome in 1 case.Conclusion:Balloon occlusion technique combined with total arch replacement and frozen elephant trunk is safe and feasible in the treatment of complex aortic arch diseases. Its organ protection effect still needs to be confirmed by large sample comparison study.

BACKGROUND:Organ dysfunction caused by hypothermic circulatory arrest continues to concern surgeons. The aortic balloon occlusion (ABO) technique can significantly shorten the circulatory arrest time in total arch replacement with frozen elephant trunk (TAR with FET). This study aims to analyze the renal protective effect of the ABO technique and to analyze the predictors of acute kidney injury (AKI) and continuous renal replacement therapy (CRRT) after TAR with FET.METHODS:Between August 2017 and September 2018, 247 patients who underwent TAR with FET were divided into ABO and moderate hypothermic circulatory arrest (MHCA) groups. The primary endpoint was postoperative AKI defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Multivariable logistic analysis was used to identify the predictors of AKI and CRRT after TAR with FET.RESULTS:With the application of the ABO technique, the circulatory arrest time was significantly shortened (ABO 4, IQR: 3-6 vs. MHCA 18, IQR: 16-20, P<0.001). Meanwhile, surgeons safely set the lowest nasopharyngeal temperature at a higher grade (ABO 28.1, IQR: 27.4-28.5 vs. MHCA 24.7, IQR: 24.1-25.1, P<0.001). The peak serum creatinine (SCr) values within 48 hours after the surgery was lower in the ABO group than in the MHCA group (ABO 124, IQR: 97-173 vs. MHCA 146, IQR: 108-221, P=0.008). The distribution of AKI grade according to the KDIGO criteria differed between the two groups (P=0.04): more patients in the ABO group were free from AKI (Grade 0) than patients in the MHCA group (33% vs. 23.1%), and the proportion of patients with high-grade AKI (Grades 2 and 3) in the ABO group was lower than that in the MHCA group (21% vs. 32%). The ABO technique was associated with reduced potential for AKI, but was not protective for CRRT.CONCLUSIONS:The ABO technique significantly shortened the circulatory arrest time and safely elevated temperature, and provided better renal protection in patients undergoing TAR with FET. The ABO technique did not reverse the need for CRRT, nor did it reduce mortality or major adverse events.

Background. Many patients required secondary open arch operation due to new aortic pathologies or complications after thoracic endovascular aortic repair (TEVAR). In this study, we investigated the outcome of secondary open arch operation after prior TEVAR. Methods. Fifty-seven consecutive patients underwent secondary open arch operation after prior TEVAR. The major indications were retrograde type A aortic dissection (n = 24), proximal new aortic dissection (n = 8), and type Ia endoleak (n = 16). An elective operation was performed in 35 patients and an emergent operation in 22. The survival and freedom from aortic events during the follow-up were evaluated with the Kaplan-Meier survival curve and the log-rank test. The survival was also analyzed with the Cox analysis. Results. The in-hospital mortality was 7.0% (4 of 57). The mean follow-up time was 32.2 +/- 19.7 months. Five late deaths occurred. The overall survival at 1 year, 3 years, and 6 years was 89.5%, 84.6%, and 79.9%, respectively. Aortic events developed in 7 patients. Freedom from aortic events after the operation at 1 year, 3 years, and 6 years was 94.2%, 83.0%, and 77.8%, respectively. There were no differences in survival and freedom from aortic events between the elective group and the emergent group. The Cox analysis identified additional coronary artery bypass grafting and hypothermic circulatory arrest as independent factors predicting survival. Conclusions. Secondary open arch operation could be performed to treat the arch pathologies after TEVAR with acceptable early and midterm outcomes. (C) 2021 by The Society of Thoracic Surgeons

Background: Total arch replacement (TAR) with frozen elephant trunk (FET) was challenging in patients with prior thoracic endovascular aortic repair (TEVAR), for complicated arch pathology and anatomy. In this study, we aimed to present our experiences in TAR with FET after prior TEVAR, and compare the clinical outcomes between the aortic balloon occlusion technique and the conventional technique. Methods: Between January 2016 and December 2019, 30 patients with prior TEVAR received TAR with FET in our hospital. The aortic balloon occlusion technique was applied in 9 patients, and the conventional technique in 21 patients. The median time interval from TEVAR to reoperation was 9 months (0-168 months). The indications for TAR with FET included retrograde type A aortic dissection, endoleak, arch false aneurysm and new ascending dissection. Results: The patients with the balloon occlusion technique had shorter cardiopulmonary bypass time than patients with the conventional technique (151.2 +/- 31.3 vs. 183.4 +/- 46.8 min, P=0.036). The aortic-clamp time was also shorter in the balloon occlusion group, but without significant difference. The hypothermia circulatory arrest duration was significantly decreased in the balloon occlusion group (5.7 +/- 4.1 vs. 21.6 +/- 7.5 min, P<0.001). The incidence of major adverse events was 13.3%, and the mortality was 6.7%. No significant differences in the incidence of major adverse events, and the mortality were noted between the two groups. Follow-up was available in 28 survivors. The mean follow-up time was 25.4 +/- 13.0 months. No late death, aortic reoperation and complications occurred during follow-up. Conclusions: TAR with FET was a safe and effective procedure in patients with prior TEVAR, with satisfactory early and late outcomes. The aortic balloon occlusion technique could be applied in these patients, and may provide some protective effects.

OBJECTIVES:The aim of this study was to propose and evaluate the new operative technique of aortic balloon occlusion in total aortic arch replacement (TAR) with the frozen elephant trunk that can significantly decrease the time of circulatory arrest and increase the hypothermic cardiopulmonary bypass (CPB) temperature. METHODS:Between 2010 and 2018, 1335 patients with aortic dissection who underwent TAR with the frozen elephant trunk were included in the study. The newest 80 cases were treated with aortic balloon occlusion. To illustrate the difference with the new procedure, 1255 conventional TAR cases served as the historical control. Femoral and right axillary artery cannulations were used for CPB and antegrade selective cerebral perfusion. Circulatory arrest was implemented at the nasopharyngeal temperature of 28°C with continuous antegrade selective cerebral perfusion. After the stent graft was inserted into the true lumen of the descending aorta, the aortic balloon in a sheath was deployed into the stent graft and positioned at the metal part of the stent graft. When the balloon was inflated with enough saline to compress the stent graft, the sheath was simultaneously pressed by hand to properly fix the balloon and avoid displacement. Then femoral perfusion could be resumed. RESULTS:The aortic balloon occlusion technique was successful in all patients, with the median duration of circulatory arrest being 5 (interquartile range 3-7) min. The 30-day mortality rate was 6.25% (5/80), whereas with the conventional method it was 9.40% (118/1255). The postoperative conscious revival (8.67 vs 11.40 h, P < 0.001) and mechanical ventilation times (19.70 vs 24.45 h, P = 0.02) were significantly shorter. Decreases in postoperative acute kidney injuries (13.75% vs 32.11%, P = 0.001) and liver injuries (8.75% vs 37.61%, P < 0.001) were also observed. The patients were transfused with lesser quantities of red blood cells, plasma and platelets. CONCLUSIONS:The aortic balloon occlusion technique is a feasible way to shorten circulatory arrest significantly, to obviate the need for deep hypothermia in TAR with the frozen elephant trunk and to provide favourable protective effects on the central nervous, haematological and visceral systems. With these satisfactory results, this technique deserves further investigation.

OBJECTIVES Our goal was to review the surgical treatment of retrograde type A aortic dissection (RTAD) after thoracic endovascular aortic repair (TEVAR) in our centre. METHODS From January 2014 to April 2018, 22 patients with RTAD after TEVAR were operated on in our centre. The mean age at operation was 52.0 ± 8.0 years old. The median interval between the primary TEVAR procedure and RTAD was 4.6 months (range 0-120 months). The postoperative mortality and morbidity rates were calculated to evaluate the early and long-term results. RESULTS Twenty patients received total arch replacement with the frozen elephant trunk technique and 2 patients received total arch replacement alone. The mean cardiopulmonary bypass time, aortic cross-clamp time and selective cerebral perfusion time were 172.4 ± 39.3, 100.1 ± 30.3 and 19.7 ± 10.5 min, respectively. The incidence of major adverse events was 18.6% (4/22), including stroke in 1 patient, myocardial dysfunction in 1 patient and renal failure necessitating dialysis in 3 patients. Death within 30 days was 13.6% (3/22 patients). The follow-up data were available for all 19 survivors. The mean follow-up period was 32.2 ± 16.2 months (range 10-62 months). No deaths or aortic-related events occurred during the follow-up period. CONCLUSIONS Total arch replacement with or without the frozen elephant trunk technique was suitable for the management of RTAD after TEVAR, with acceptable early and long-term results.

Flow fields in the distal end-to-side anastomosis of coronary artery bypass graft are associated with intimal hyperplasia and bypass failure. This work aims to demonstrate the effect of anastomotic angle and diameter ratio on flow field of coronary artery bypass graft. The flow fields inside polydimethylsiloxane models of coronary artery bypass graft with various anastomotic angles (α = 30°, 45°, 60° and 75°) and different diameter ratios (Φ = 0.78 and 1.11) are investigated using particle image velocimetry and computational fluid dynamics method under pulsatile flow condition. The results show that the anastomotic angle is positively correlated with the number and area of the recirculation zone, and the flow field disturbance at the anastomosis will develop in the same direction. Compared with that of Φ = 0.78, when Φ = 1.11, the flow fields at the anastomosis are relatively smoother with less turbulence.

Background Data on the clinical features and surgical outcomes of type A intramural hematoma (IMH) in Chinese patients are very limited. We aimed to present the surgical experiences on type A IMH in our center, and report early and late outcomes. Methods From February 2012 to April 2018, 106 consecutive patients underwent open surgery for type A IMH at our hospital. We adopted emergent operation for patients with cardiac tamponade or other severe complications, and recommended initial medical treatment followed by elective surgery for stable patients. The composite endpoints included operative mortality, permanent nerve damage (stroke, paraplegia), and new-onset renal failure necessitating hemodialysis. Risk factors for operative mortality and the composite endpoints were identified using univariable and multivariable logistic regression model analysis. The survival and freedom from aortic events were analyzed using a Kaplan-Meier surviving curve and a log-rank test. Results Except 1 patient receiving emergent surgery (within 24 hours from onset) because of cardiac tamponade and cerebral malperfusion, all patients received initial medical treatment and delayed surgery. Two patient developed pericardial tamponade while waiting for surgery, and then received emergent surgery. Preoperative conversion to aortic dissection (AD) was noted in no patient. The operative techniques included ascending aorta replacement in 9 patients, hemiarch replacement in 18 patients, total arch replacement (TAR) with frozen elephant trunk (FET) in 45 patient and hybrid aortic arch repair in 34 patients. The mean cardiopulmonary bypass (CPB) time and cross-clamp time were 138.7±41.6 and 79.3±27.8 min, respectively. The operative mortality was 1.9% (2/106). And the composite endpoints occurred in 7 patients. Multivariable logistic regression analysis showed CPB time ≥200 min and chronic kidney disease were risk factors for the composite endpoints. The follow-up data were available in 97 survivors, with the mean follow-up time of 30.8±16.2 months. Three patients died and 5 patients developed aortic events during the follow-up. The overall survival at 1-, 3- and 5-year were 97.0%, 95.3%, and 79.4%, respectively. And freedom from aortic events at 1-, 3- and 5-year were 97.7%, 95.3% and 89.4%, respectively. Conclusions Our strategy had got low mortality and excellent mid-term survival in patients with type A IMH. Therefore, our strategy was suitable for the surgical repair of type A IMH in Chinese population.

This study aimed to compare clinical outcomes of patients treated by total arch replacement (TAR) with frozen elephant trunk (FET), aortic balloon occlusion (ABO) technique and hybrid arch repair (HAR). Between January 2017 and July 2019, 643 consecutive patients with aortic arch diseases were eligible for TAR, including 356 in conventional FET, 112 in ABO based on FET, and 175 in HAR. A retrospective cohort analysis of perioperative results was undertaken, performed with inverse probability weighting. The primary endpoint was composite endpoints included 30-day mortality, stroke, paraplegia, hemodialysis, reintubation, and intra-aortic balloon pump or extracorporeal membrane oxygenation support, and visceral dysfunction was secondary endpoint. Overall in-hospital mortality was 2.2% (FET = 2.5% vs ABO = 0 vs HAR = 2.9%, P= 0.210). Parallel early outcomes were demonstrated among three groups. ABO group was associated with significantly shorter circulatory arrest time (5, IQR 3-7 vs 16, IQR 14-18 minutes, P < 0.001), and a lower incidence of visceral dysfunction compared with FET group (25.1% vs 47.3%, P= 0.003). Patients receiving ABO suffered a significantly lower rate of prolonged ventilation (more than 72 hours; P= 0.014). Furthermore, a tendency toward decreasing composite endpoints was suggested in ABO (7.2%) compared with FET (15.5%, P= 0.061) and HAR (19.8%, P= 0.032). ABO technique obtains considerable early clinical outcomes for TAR compared with conventional FET and HAR, which could be a feasible and effective approach for patients with aortic arch diseases.

Aortico-left ventricular tunnel (ALVT) is a rare, abnormal, paravalvular communication between the aorta and the left ventricle. ALVT can be associated with a variety of congenital heart diseases, but there are only a few reports of ALVT associated with bicuspid aortic valve (BAV). Herein, we report a case of an 11-year-old boy who successfully underwent aortic valve sparing root replacement for ALVT with BAV and aortic root aneurysm. (C) 2020 by The Society of Thoracic Surgeons.

OBJECTIVES: Our goal was to investigate the surgical strategy for type Ia endoleak after thoracic endovascular aortic repair (TEVAR) by reporting our experiences. METHODS: From November 2012 to September 2019, a total of 23 patients received surgical management for type Ia endoleak after TEVAR. RESULTS: The operations included total arch replacement with the frozen elephant trunk technique in 15 patients, direct closure of the endoleak in 2 patients, hybrid aortic arch repair in 4 patients, arch debranching with TEVAR in 1 patient and left common carotid artery to left subclavian artery bypass with TEVAR in 1 patient. Among 21 patients with cardiopulmonary bypass (CPB), the mean CPB and aortic cross-clamp times were 146.742.2 and 81.0 +/- 43.3min, respectively. The selective cerebral perfusion time was 18.8 +/- 8.2min in 17 patients with hypothermic circulatory arrest. The in-hospital mortality was 8.7% (2/23). Type Ia endoleak was sealed successfully after surgery in 95.5% (21/22) of patients. The follow-up data were available for all 21 survivors. The median follow-up period was 18months (range 1-84months). During the follow-up period, a total of 8 patients died or had aortic events, including 5 deaths and 6 aortic events. CONCLUSIONS: Different surgical strategies could be selected to treat patients with type Ia endoleak after TEVAR, with acceptable early and late outcomes.

Leaflet thrombosis is a typical secondary valvular disease after aortic valve replacement, and abnormal hemodynamic characteristics are crucial in its development. In this study, the effects of angle between the longitudinal axis of the aortic valve and that of the ascending aorta ($\alpha =0^\circ$, $\alpha =5^\circ$, $\alpha =10^\circ$ and $\alpha =15^\circ$) on the velocity, vorticity and viscous shear stress distribution are investigated using particle image velocimetry (PIV). It is of great significance to understand the hemodynamic mechanism of thrombosis after aortic valve replacement. The results show that the transvalvular flow in the aortic root is centrosymmetric flow when $\alpha =0^\circ$, while it tilts to the side of left coronary artery when $\alpha =5^\circ$, $\alpha =10^\circ$ and $\alpha =15^\circ$. The transvalvular flow tilts with the increasing of tilted angle and impacts on the wall of the ascending aorta, damaging the endothelial cells and causing thrombosis. In addition, the velocity within the aortic sinus increases and the vortex also moves toward the bottom of the aortic sinus with aortic valve tilted, which is unfavorable for the blood flowing from the coronary artery ostium to the myocardium for blood supply. Meanwhile, the high vorticity and high viscous shear stress area of the aortic root also tilts to the side of left coronary artery. And the high vorticity area of the aortic sinus is located at the bottom of the aortic sinus and the high viscous shear stress area is distributed at the wall of the aortic sinus. The vorticity and viscous shear stress are realy high when there is a mismatch between the ascending aorta longitudinal axis and that of the aortic valve, especially $\alpha =10^\circ$ and $\alpha =15^\circ$, providing a favorable environment for thrombosis. The results benefit to contribute theoretical bases and technical reference for the selection of clinical aortic valve replacement surgical parameters and that of the avoidance of secondary valvular disease.