Retrograde Type A Dissection Research Articles

Spinal cord ischemia and reinterventions following thoracic endovascular repair for acute type B aortic dissections

ObjectiveThe technical aspects of thoracic endovascular aortic repair (TEVAR) for acute type B aortic dissection (TBAD), specifically the location of proximal seal zone (PSZ) (need to cover the left subclavian artery [LSA]), distal seal zone (DSZ) (length of aortic coverage), benefit of LSA revascularization, and prophylactic lumbar drainage are still debated. Each of these issues has potential benefits but also has known risks. This study aims to identify factors associated with reintervention and spinal cord ischemia (SCI) following TEVAR for acute TBAD with a zone 3 entry tear. MethodsThe Vascular Quality Initiative was queried for TEVARs performed for acute TBAD with zone 3 entry tear, zone 3 proximal zone of disease, treated with TEVAR extending between zone 2 and zone 5. The primary outcomes were SCI and related reintervention. Secondary outcomes were stroke, arm ischemia, and retrograde type A dissection (RTAD). The exposure variables were PSZ 2 vs 3, DSZ 4 vs 5, prophylactic lumbar drain, and LSA revascularization. Univariate analyses were conducted with χ2 analysis, and multivariable logistic regression was used to evaluate association with outcomes. ResultsOf 583 patients who met inclusion criteria, 266 had PSZ 2 and 317 had PSZ 3. On univariate analysis, PSZ 2 was associated with a higher rate of reintervention, but PSZ2 was not significant on multivariable analysis after accounting for age, sex, race, smoking, PSZ, DSZ, prophylactic lumbar drain, and LSA patency. PSZ 2 was not associated with SCI, arm ischemia, or RTAD. PSZ 2 was associated with a trend towards a higher rate of stroke. DSZ 4 and DSZ 5 were performed in 161 and 422 TEVARs, respectively, and DSZ 5 was associated with a higher rate of SCI on univariate (3 [1.9%] vs 39 [9.2%]; P = .01) and multivariable (odds ratio, 7.384; 95% confidence interval, 2.193-24.867; P = .001) analyses. Prophylactic lumbar drain placement was not statistically significantly associated with SCI, but lack of postoperative LSA patency was associated with SCI (odds ratio, 2.966; 95% confidence interval, 1.016-8.656; P = .05). ConclusionsThis study found that PSZ 2 was not associated with lower reinterventions or higher rates of SCI but trended towards a higher rate of stroke than PSZ 3. Additionally, DSZ 5 was strongly associated with SCI when compared with DSZ 4, highlighting the importance of limiting aortic coverage to coverage of the proximal entry tear when possible.

Physician Modified Fenestrated Endografts for Endovascular Aortic Arch Repair in Zone 0

This multicentre study aimed to assess the early and midterm outcomes of physician modified fenestrated endografts (PMEGs) for endovascular aortic arch repair in zone 0. Between 2018 and 2022, a retrospective study was conducted in three centres of consecutive patients undergoing endovascular aortic arch repair in zone 0 with PMEGs. Endpoints included technical success, 30 day mortality rate, major adverse events, secondary interventions, stent stability, target vessel patency, and overall survival. A total of 54 patients (mean age 63 years; 45 males) with aortic arch pathology were included, comprising aortic dissections (n= 32; 59%) and aortic arch aneurysms (n= 22; 41%). Technical success was 98%. One patient died from stroke within 30 days. Major adverse events included stroke (n= 4; 7%), retrograde type A dissection (RTAD) (n= 3; 6%), and acute kidney injury (n= 2; 4%). During a median follow up of 12 months, there were two deaths (4%) of unknown cause at one month and 1.5 months, and no aortic related death. Type Ia, type Ic, and type IIIc endoleaks were observed in two (4%), three (6%), and two (4%) patients, respectively. No vessel stenosis was observed. Re-intervention was required in 10 patients (19%). Estimates of overall survival, freedom from secondary intervention, and freedom from target vessel instability at one year were 94.2% (standard error [SE] 3.3%), 81.8% (SE 6.0%), and 92.0% (SE 4.5%), respectively. This study has demonstrated the efficacy of PMEGs for zone 0 endovascular aortic arch repair, with acceptable technical success and mortality rates. Stroke, RTAD, and re-intervention rates remain a concern for endovascular therapy. A larger population and long term outcomes are required to assess the safety and durability of this technique as a beneficial choice for endovascular aortic arch repair in specialised centres.

Surgical Treatment for Type A Aortic Dissection after Endovascular Aortic Repair: A 12-year, Single-Center Study.

This study aims to investigate the clinical manifestations, operative techniques, and outcomes of patients who undergo open repair after thoracic endovascular aortic repair (TEVAR). From January 2010 to June 2022, 113 consecutive type A aortic dissection (TAAD) patients underwent secondary open operation after TEVAR at our institution, and the median interval from primary intervention to open surgery was 12 (1.9-48.0) months. We divided the patients into two groups (RTAD (retrograde type A dissection) group, N = 56; PNAD (proximal new aortic dissection) group, N = 57) according to their anatomical features. Survival analysis during the follow-up was evaluated using a Kaplan-Meier survival curve and a log-rank test. The 30-day mortality was 6.2% (7/113), the median follow-up period was 31.7 (IQR 14.7-65.6) months, and the overall survival at 1year, 5years, and 10years was 88.5%, 88.5%, and 87.6%, respectively. Fourteen deaths occurred during the follow-up, but there were no late aorta-related deaths. Three patients underwent total thoracoabdominal aortic replacement 1year after a second open operation. The RTAD group had a smaller ascending aorta size (42.5 ± 7.7mm vs 48.4 ± 11.4mm; P < .01) and a closer proximal landing zone (P < .01) compared to the PNAD group. However, there were no differences in survival between the two groups. TAAD can present as an early or a late complication after TEVAR due to stent-grafting-related issues or disease progression. Open operation can be performed to treat TAAD, and this has acceptable early and mid-term outcomes. Follow-up should become mandatory for patients after TEVAR because these patients are at increased risk for TAAD.

A systematic review and meta-analysis of retrograde type A aortic dissection after thoracic endovascular aortic repair in patients with type B aortic dissection.

Retrograde type A dissection (RTAD) is a devastating complication of thoracic endovascular repair (TEVAR) with low incidence but high mortality. The objective of this study is to report the incidence, mortality, potential risk factors, clinical manifestation and diagnostic modalities, and medical and surgical treatments. A systematic review and single-arm and two-arm meta-analyses evaluated all published reports of RTAD post-TEVAR through January 2021. All study types were included, except study protocols and animal studies, without time restrictions. Outcomes of interest were procedural data (implanted stent-grafts type, and proximal stent-graft oversizing), the incidence of RTAD, associated mortality rate, clinical manifestations, diagnostic workouts and therapeutic management. RTAD occurred in 285 out of 10,600 patients: an estimated RTAD incidence of 2.3% (95% CI: 1.9-2.8); incidence of early RTAD was approximately 1.8 times higher than late. Wilcoxon signed-rank testing showed that the proportion of RTAD patients with acute type B aortic dissection (TBAD) was significantly higher than those with chronic TBAD (P = .008). Pooled meta-analysis showed that the incidence of RTAD with proximal bare stent TEVAR was 2.1-fold higher than with non-bare stents: risk ratio was 1.55 (95% CI: 0.87-2.75; P = .13). Single arm meta-analysis estimated a mortality rate of 42.2% (95% CI: 32.5-51.8), with an I2 heterogeneity of 70.11% (P < .001). RTAD is rare after TEVAR but with high mortality, especially in the first month post-TEVAR with acute TBAD patients at greater risk as well as those treated with proximal bare stent endografts.

Thoracic Endovascular Aortic Repair (TEVAR) for Primary Retrograde Type A Aortic Dissection

Acute aortic dissection is an emergent and life-threatening condition. Retrograde Type A dissection (RTAD) can occur primarily or due to a complication of Type B dissection that often requires open repair, a highly morbid operation. While management of Type A and Type B dissections is clear, the literature is sparse regarding management of RTAD. We describe a case where the patient presented with a Type B dissection complicated by retrograde propagation, resulting in RTAD. We performed a Thoracic Endovascular Aortic Repair (TEVAR) as an alternative to standard open repair. The patient tolerated the procedure well and was discharged with resolution of the false lumen. Instead of treating a radiographic finding with a highly morbid operation, it is important to evaluate if an endovascular approach is a reasonable option to treat RTAD. Each case must be evaluated individually, but we believe that TEVAR may be an alternative intervention in specific cases.

Endovascular Management of Aortic Arch Diseases: Current Status and Future Trends

Treatment of aortic arch (AA) diseases is challenging for surgeons. Conventional open surgery remains the “gold standard” but is associated with significant morbidity and mortality despite improvements in techniques. In the last 2 decades, thoracic endovascular aortic repair (TEVAR) has become the first-line treatment for diseases of the descending aorta, and its indications have expanded gradually. Various strategies have been proposed to preserve supra-aortic branches in TEVAR: hybrid technique, chimney technique, fenestration technique (including custom-made fenestrated or “scalloped” stent grafts, in situ fenestration, and physician-modified fenestration), and branched stent grafts. Though acceptable outcomes of endovascular aortic repair have been documented, the evidence regarding its long-term safety and efficacy is lacking, and concerns remain about the risk of cerebrovascular events, retrograde type-A dissection, endoleaks, and branch occlusion. This review discusses the current status and progress of endovascular repair of the AA, and looks toward future trends. We believe that multidisciplinary collaboration of a “HENDO” team (professionals in hybrid repair, endovascular repair, open surgery, cardiovascular anesthesia, and genetics) is essential for future repair of the AA to provide the optimal treatment.

Retrograde type A dissection in the Vascular Quality Initiative thoracic endovascular aortic repair for dissection postapproval project: Presented at the Forty-fifth Annual Meeting of the Southern Association for Vascular Surgery (Virtual), Scottsdale, Ariz, January 27-30, 2021.

Background Retrograde dissection (RD) can be a serious complication after thoracic endovascular aortic repair (TEVAR), with retrograde type A dissection (RTAD) particularly life-threatening. Prior studies have suggested that treatment timing, anatomic characteristics, device selection, and procedural conduct of TEVAR performed for type B aortic dissection could mitigate the occurrence of RD. The Vascular Quality Initiative TEVAR for Dissection Registry is an ongoing project meant to satisfy Food and Drug Administration requirements for postmarket approval surveillance of the Gore conformable TAG thoracic endoprosthesis (W.L.

Impact of high-risk features and timing of repair for acute type B aortic dissections

ObjectiveThe new Society for Vascular Surgery/Society for Thoracic Surgery reporting standards for type B aortic dissection (TBAD) categorize clinical presentations of aortic dissection into uncomplicated, high-risk features (HRF), and complicated groups. Although it is accepted that complicated dissections require immediate repair, the optimal timing of repair for HRF has yet to be established. This study aims to identify the ideal timing of thoracic endovascular aortic repair (TEVAR) for HRF, as well as outcomes associated with specific HRF. MethodsThe Vascular Quality Initiative was queried for TEVARs performed for acute and subacute TBAD with HRF from 2014 to 2020. Rupture, malperfusion, and uncomplicated patients were excluded. HRF were defined per the guidelines as refractory hypertension, pain, or rapid expansion/aneurysm of more than 40 mm. The primary outcomes were in-hospital/30-day mortality and 1-year survival with primary exposure variables being days from symptoms to repair and number of HRFs. Secondary outcomes were spinal cord ischemia, stroke, and retrograde type A dissection (RTAD). ResultsOf the 1100 patients who met inclusion criteria, 811 had one HRF, 249 had two, and 40 had three. There were no significant differences in primary or secondary outcomes based on number of HRFs. There were 309 patients who underwent repair at 0 to 2 days, 262 at 3 to 6 days, 270 at 7 to 14 days, and 259 at 15 days or more. TEVAR performed at 15 days or more was independently associated with lower in-hospital/30-day mortality (odds ratio, 0.38; P = .0388) and improved 1-year survival. Postoperative stroke was associated with earlier repair (0-2 days). There was no association of timing of repair with spinal cord ischemia, retrograde type A dissection or reintervention. ConclusionsTEVAR for TBAD with HRF delayed at least 15 days from symptom onset is associated with improved survival, supporting the theory that it is best to delay TEVAR until the subacute phase. Additionally, TEVAR delayed at least 3 days is associated with a decrease in stroke. Having more than one HRF was not associated statistically with worse outcomes. Because the classification of HRF is relatively new and without guidelines for repair, this study highlights the risks of early intervention for HRF and suggests that these patients seem to benefit from at least a short stabilization period before TEVAR.

Retrograde type A dissection in the Vascular Quality Initiative thoracic endovascular aortic repair for dissection postapproval project

BackgroundRetrograde dissection (RD) can be a serious complication after thoracic endovascular aortic repair (TEVAR), with retrograde type A dissection (RTAD) particularly life-threatening. Prior studies have suggested that treatment timing, anatomic characteristics, device selection, and procedural conduct of TEVAR performed for type B aortic dissection could mitigate the occurrence of RD. The Vascular Quality Initiative TEVAR for Dissection Registry is an ongoing project meant to satisfy Food and Drug Administration requirements for postmarket approval surveillance of the Gore conformable TAG thoracic endoprosthesis (W.L. Gore & Associates, Flagstaff, Ariz), Medtronic Valiant thoracic stent graft (Medtronic, Santa Rosa, Calif), and Cook Medical dissection devices (Cook Medical, Bloomington, Ind) and provides a unique source of evaluation for RTAD in a prospectively collected real-world registry. MethodsA total of 588 consecutive patients at 49 institutions had undergone TEVAR for acute (<30 days; n = 336) and chronic (≥30 days; n = 252) type B aortic dissection were included. The occurrence of RD as reported by the participating centers and de-identified source documents were reviewed and confirmed independently by two of us (A.W.B. and G.W.). The demographics, procedural and device data, and anatomic considerations were evaluated, and the devices were grouped in a de-identified manner as Gore, Medtronic, and other. ResultsThe mean follow-up was 889 days (median, 658 days), and 408 patients had completed follow-up data available for >1 year. A total of 19 patients with RD (3.2%) were identified, 9 of whom had been treated for acute and 10 for chronic dissection, a 2.7% and 4.0% incidence, respectively (P = .48, acute vs chronic). Of the 19 RD cases, 15 were RTAD, 6 after treatment of acute and 9 after treatment of chronic dissection, a 1.8% and 3.6% incidence, respectively (P = .19, acute vs chronic). Five cases of RD had occurred intraoperatively (four of which were RTAD). The median time to RD and RTAD was 62 and 69 days, respectively (range, 0 to 1600 days). Of the 15 patients with RTAD, 12 had undergone surgical repair and 2 had not undergone repair; the treatment of one was unknown. The overall mortality was 33.3% (5 of 15). The factors associated with RTAD included more extensive dissection (mean, 5.6 zones without RTAD vs 8.5 zones with RTAD; P = .001), female sex (28.3% female without RTAD vs 53.3% with RTAD; P = .04), and non-White race (62.7% White without RTAD vs 33.3% White with RTAD; P = .05). Mean oversizing was not significantly different for those without RTAD compared with that for those with RTAD (14.0% vs 14.2%; P = .92). The device type was anonymized in this project; however, we found no significant differences between the Gore, Medtronic, and all other devices. ConclusionsThe rate of RD in the present real-world postapproval project was consistent with that from previously reported studies, including highly controlled pivotal studies. Device type was not predictive of RD, and the newly identified risk factors for RTAD include more extensive dissection and a trend toward a greater risk for female sex and non-White race.

Computational Investigation and Histopathological Validation of Interaction Between Stent Graft and Aorta in Retrograde Type A Dissection After TEVAR in Canine Models

Purpose: Retrograde type A dissection (RTAD) after thoracic endovascular aortic repair (TEVAR) has been a major drawback of endovascular treatment. To our knowledge, no studies have simulated and validated aortic injuries caused by stent grafts (SGs) in animal models. Therefore, the aim of this study was to evaluate and quantify the SG–aorta interaction through computational simulations and to investigate the underlying mechanism through histopathological examinations. Methods: Two custom-made Fabulous® (DiNovA Meditech, Hang Zhou, China) SGs were implanted in 2 canine aortas with a 5-mm difference in the distance in landing locations. The aortic geometries were extracted from RTAD and non-RTAD cases. A computational SG model was assembled based on the implanted SG using the software Pro-ENGINEER Wildfire 5.0 (PTC Corporation, Needham, Mass). TEVAR simulations were performed 7 times for each canine model using Abaqus software (Providence, RI, USA), and the maximum aortic stress (MAS) was calculated and compared among the groups. Three months after SG implantation, the canine aortas were harvested, and were examined using hematoxylin and eosin staining and Elastica Van Gieson (EVG) staining to evaluate histopathological changes. Results: In the computational models for both canines, MAS was observed at the proximal bare stent (PBS) at aortic greater curve. The PBS generated higher stress toward the aortic wall than other SG parts did. Moreover, the MAS was significantly higher in canine No.1 than in canine No.2 (0.415±0.210 versus 0.200±0.160 MPa) (p<0.01). Notably, in canine No.1, an RTAD developed at the MAS segment, and histopathological examinations of the segment showed an intimal flap, a false lumen, elastin changes, and medial necrosis. RTAD was not observed in canine No.2. In both SG-covered aortas, medial necrosis, elastic fiber stretching, and inflammatory infiltration were seen. Conclusion: The characteristic MAS distribution remained at the location where the apex of the PBS interacted with the aortic wall at greater curve. RTAD histopathological examinations showed intimal damage and medial necrosis at the proximal landing zone, at the same MAS location in computational simulations. The in vivo results were consistent with the computational simulations, suggesting the MAS at greater curve may cause RTAD, and the potential application of computational simulation in the mechanism study of RTAD.

Early outcomes associated with use of the Zenith TX2 Dissection Endovascular Graft for the treatment of Stanford type B aortic dissection

ObjectiveTo evaluate short term outcomes related to the use of the Zenith TX2 Dissection Endovascular Graft (ZDEG) and the Zenith Dissection Bare stent (ZDES) for the treatment of Stanford type B aortic dissections. MethodsThis retrospective multicenter case cohort study collated data from 10 European institutions for patients with both complicated and uncomplicated type B aortic dissection treated with ZDEG and ZDES between 2011 and 2018. The primary end point was mortality at 30 and 90 days. Secondary end points included complications related to TEVAR, such as, type Ia endoleak, stroke, paraparesis, paraplegia, and retrograde type A dissection (RTAD). Statistical analysis was carried out using the t test, or one-way analysis of variance and the χ2 or Fisher exact tests. ResultsWe treated 120 patients (87 male; mean age, 62.7 ± 12.2years) either in the acute 76 (63.3%), subacute 16 (13.3%), or chronic 28 (23.3%) phase. Seven patients (5.8%) died within 30 days after the index procedure and two (1.7%) between 30 and 90 days. There was one instance of postoperative RTAD in a patient treated for rupture. Stroke and paraplegia occurred in three (2.5%) and five (4.2%), patients, respectively. Eight patients (6.7%) had a type Ia endoleak in the perioperative period. There were no instances of paraplegia, no permanent dialysis, and no requirement for adjunctive superior mesenteric or celiac artery stenting in the 33 patients (27.5%) who were treated by concurrent placement of ZDES distal to the ZDEG. The length and distal oversizing of ZDEG components used was less in this group. ConclusionsThe present series demonstrates a low (<1%) RTAD rate and favorable morbidity and mortality. The lower rate of paraplegia, dialysis, and visceral artery stenting in the cohort that had adjunctive use of ZDES is compelling and merits further assessment.

A Novel Vascular-Friendly Thoracic Stent Graft for Endovascular Repair of Acute Complicated Type B Aortic Dissection.

Purpose: To evaluate the safety and efficacy of a novel vascular-friendly thoracic stent graft for patients with acute complicated type B aortic dissection (ac-TBAD).Methods: A multicenter retrospective study was undertaken in which we prospectively collected data in consecutive ac-TBAD patients treated by thoracic endovascular aortic repair (TEVAR) with the Ankura Thoracic Stent. Complications, true lumen rate (TLR), and mortality were recorded. Follow-up computed tomography angiography (CTA) was performed at 1, 6, and 12 months postoperatively and yearly thereafter.Results: Altogether, 63 patients with ac-TBAD in four medical centers were included. No deaths or serious complications occurred during the perioperative period. The mean follow-up time was 30.1 ± 18.9 months. All-cause mortality rate was 3.1% (n = 2). TEVAR-related mortality rate was 1.6% (n = 1) because of retrograde type A dissection (RTAD) at 6 months. The other death was caused by acute myocardial infarction (AMI) during the third postoperative month. A distal endoleak detected at 3 months in one patient (1.6%) was treated by reintervention. The use of this novel vascular-friendly thoracic stent graft in ac-TBAD postoperative patients significantly improved their TLR.Conclusion: The novel vascular-friendly thoracic stent graft showed satisfactory results, with favorable stability of the aortic diameter during follow-up.

Ten-Year Clinical Characteristics and Early Outcomes of Type B Aortic Dissection Patients With Thoracic Endovascular Aortic Repair.

This study examined the 10-year hospitalization characteristics, economic patterns and early clinical outcomes of type B aortic dissection (TBAD) patients that underwent thoracic endovascular aortic repair (TEVAR) in one high-volume hospital in China. We performed a population-based retrospective analysis based on electronic medical record system data provided by Zhongshan Hospital Fudan University from 2009 to 2018. We identified 1,367 cases of TBAD patients with TEVAR over the past decade. The total incidence of in-hospital complications was 7.6% (104 of 1,367), among which acute kidney injury (AKI) had the highest incidence (3.1%, 42 of 1,367). Aortic-related reintervention was performed in 7 patients (0.5%). The overall aortic-related in-hospital mortality rate was 2.7% (37 of 1,367) and had no significant time-varying trend (P = 0.2). Among these, 27% of in-hospital deaths were caused by retrograde type A dissection (RTAD). Chronic TBAD had a higher risk of in-hospital death versus acute TBAD, with a risk ratio of 2.69 (95% confidence interval [CI]: 1.19-6.09). Patients with hypertension (risk ratio 4.63, 95% CI: 1.38, 15.54) also had a higher in-hospital death risk. These 2 factors were also the predictive factors for the composite endpoint of in-hospital adverse events (risk ratio 2.17, 95% CI: 1.43, 3.29 and risk ratio 4.83, 95% CI: 1.90, 12.28, respectively), in addition to Marfan syndrome (risk ratio 4.05, 95% CI: 1.61, 10.19). The average length of hospitalization significantly declined during the past decade (annual percentage change -6.3%, 95% CI -8.2 to -4.3), and the stent-grafts (SGs) cost was the main expenditure of the total hospitalization costs. Our study showed a favorable early outcome of TEVAR over the past decade. Greater attention should be paid to certain risk factors in order to reduce the in-hospital adverse events. SG expenditure is still the primary economic burden on Chinese TBAD patients.

Endovascular treatment of chronic aortic dissection with fenestrated and branched stent grafts

ObjectiveChronic aortic dissection with aneurysm development that includes the aortic arch and/or thoracoabdominal aorta (TAAA) is traditionally treated with open or hybrid surgery. Total endovascular treatment with fenestrated and branched aortic repair (F/B-EVAR) has recently been introduced as a less invasive alternative. The aim was to report the short- and midterm outcomes from a single tertiary vascular center. MethodsAll patients with chronic aortic dissection treated with F/B-EVAR from 2010 to 2019 at Uppsala University Hospital were identified. Perioperative and postoperative parameters were analyzed, with focus on short- (<30 days) and midterm survival, complication, and reintervention rates. ResultsF/B-EVAR was performed on 26 patients (median age, 63 years; range, 33-87 years; 18 men; median aortic diameter, 70 mm; range, 50-98 mm); with a median follow-up of 23 months (range, 0.5-118.0 months). One patient underwent both arch and TAAA repair. Overall, 13 arch repairs (arch group) after type A (n = 8) and type B (n = 5) dissection (all elective) were performed, and 14 TAAA repairs (TAAA group) after type A (n = 5) and type B (n = 9) dissection (one rupture). A total of 72 aortic branches were targeted (22 arch, 50 TAAA). Short-term technical success was achieved in 24 of 27 procedures (89%). Failures were related to one intraoperative retrograde type A dissection (RTAD) requiring open conversion (arch group), one persistent type IC endoleak on completion angiography (arch group), and one persistent type III endoleak (TAAA group). Mortality was 4% (n = 1) at 30 days and related to a second RTAD that occurred after discharge and was found on autopsy. Both RTADs occurred in patients with chronic type B dissection undergoing fenestrated arch repair. Paraplegia occurred in three cases (two arch, one TAAA) (11%), none permanent, and stroke in three cases (one arch, one TAAA) (11%); one was permanent. In the midterm, endoleaks were detected in 12 patients (44%); persistent false lumen flow (n = 3), type IB (n = 1), type IC (n = 3), type II (n = 7), and type IIIC (n = 2). The 3-year survival (Kaplan-Meier) of the arch repair was 75% and for the TAAA, 93%. Freedom from reintervention at 3 years were 100% for arch repairs and 48% for TAAA. In patients with a follow-up of more than 6 months (n = 23), all had stable or decreased aortic diameters and complete false lumen thrombosis at the level of stent graft was present in 65% (n = 15). ConclusionsEndovascular treatment of postdissection aneurysms is feasible, with acceptable short-term and midterm outcomes. RTAD after fenestrated and branched endovascular arch repair warrants caution when performed on patients with native ascending aortas, and reinterventions are frequent in TAAA repair.

Prevention of Retrograde Ascending Aortic Dissection by Cardiac Pacing During Hybrid Surgery for Zone 0 Aortic Arch Repair

Retrograde type A dissection (RTAD) after zone 0 hybrid aortic arch repair is highly lethal and not infrequent complication. The aim of this study was to assess the safety and effectiveness of rapid cardiac pacing as an adjunctive tool to prevent RTAD during or after hybrid procedures for zone 0 disease. We performed a retrospective review of 42 consecutive patients with zone 0 hybrid aortic arch repair between November 2004 and January 2018. Right ventricular pacing was carried out through unipolar electrodes attached to the epicardium of the right ventricle through the sternotomy (the indifferent electrode was in the subcutaneous tissue). Pacing was utilised during the clamping of the ascending aorta, release of the aortic clamp, and stent-graft deployment. Operative indications were aortic arch aneurysm 45% (n=19), aortic arch dissection 45% (n=19), traumatic rupture of isthmus 7% (n=3), and type IA endoleak 2% (n=1). Urgent procedures 48% (n=20). The mean proximal aortic diameter was 34.14±2.9mm. Mean stent-graft oversizing was 12.97±3.4%. The 30-day mortality rate was 14% (n=6). RTAD was observed in 7% (n=3). The actuarial survival rate was 74% over a mean follow-up of 50±30.2months. Since January 2013, rapid right ventricular pacing (overdrive pacing at a rate of 200 beats/min) was systematically used (n=24). No RTAD was observed in this group of patients. Rapid right ventricular pacing reduced significatively the risk of RTAD (P=0.038). Rapid right ventricular pacing is an effective method of inducing hypotension and appears to decrease the risk of retrograde type A dissection after zone 0 hybrid aortic arch repair.

Long-term Results of Thoracic Endovascular Aortic Repair for Type B Aortic Dissection and Risk Factors for Survival

Purpose: To compare characteristics of acute, subacute, and chronic type B aortic dissection and their influence on long-term results of thoracic endovascular aortic repair (TEVAR). Materials and Methods: In a single-center, retrospective cohort study, 314 patients (median age 52 years; 244 men) with acute (n=165), subacute (n=115), or chronic (n=34) type B aortic dissection underwent TEVAR between January 2009 and December 2013. Patient demographics, risk factors, and imaging characteristics were compared among the groups. Univariable and multivariable Cox regression analyses were performed to identify any factors influencing survival. Results: The acute and subacute patients exhibited more complications at presentation than chronic patients. However, the chronic patients exhibited more aneurysmal dilatation (p<0.001) and true lumen collapse (p<0.001). Over a mean follow-up of 68.1±22.9 months (range 2–108), subacute patients showed a lower reintervention rate (3.6% vs 12.1% vs 12.1%, p=0.045), a lower major complication rate (14.4% vs 33.1% vs 27.3%, p=0.002), and better cumulative overall survival (p=0.03) than the acute and chronic groups, respectively. Furthermore, acute patients developed more stent-graft–induced distal erosion (p=0.017) and retrograde type A dissection (RTAD) (p=0.036), whereas chronic patients had less aortic remodeling in the stented segment (p<0.001), distal thoracic aorta (p<0.001), and abdominal aorta (p=0.047). Finally, multivariable analysis demonstrated age >52 years, visceral malperfusion, and RTAD as independent factors influencing overall survival; aneurysmal dilatation, rupture/impending rupture, and RTAD were independent factors influencing aorta-specific survival. Conclusion: Acute and subacute patients had increased risks of rupture and complications at presentation, whereas chronic patients had increased risks for aneurysmal dilatation. From a long-term perspective, the subacute phase might be an optimal time for TEVAR in cases of type B aortic dissection that do not need emergent interventions. The risk factors influencing survival should be identified, carefully managed, and possibly prevented.

Outcome of fenestrated and Branched Endovascular Repair of Aortic Arch Pathology

Introduction: Operative management of aortic arch pathology remains a complex challenge and an area that poses significant obstacles to a totally endovascular approach. The aim of this study was to report the outcomes of custom-made fenestrated and branched endovascular aortic repair involving the arch (fEVARA and bEVARA) in our aortic center. Methods: All patients treated with fEVARA or bEVARA were reviewed. Indications for intervention, technical success, 30-day mortality and post-operative sequelae were examined. Results: Between May 2014 and February 2019, 24 patients underwent f/bEVARA. The mean age was 68 years (range 45-85); 9 were female. The median follow up was 16 months (range 1-59). The indications for intervention included degenerative aneurysm (n=11) and post dissection aneurysm (n=13). 4 patients had a connective tissue disorder and 11 had undergone previous open ascending aortic repair. 6 cases were part of further staged aortic intervention. Stent graft morphology included: 6 fenestrated grafts (Left Subclavian), 7 fenestration + scallop (Left Subclavian and Left Carotid artery), 1 scallop only (Left Subclavian); and 10 branched cases (Brachiocephalic, left Carotid and +/- Left Subclavian artery). The proximal landing was zone 0 (n=10), zone 1 (n=7) and zone 2 (n=7). 30-day mortality was 4% (n=1 retrograde type A dissection (RTAD) post discharge). Four non-disabling strokes and one non-fatal RTAD occurred within 30-days. Three of these patients had been treated with a fenestration and scallop combination, and both RTADs occurred in patients with fEVARA for chronic type B dissection. One additional late aortic death occurred (descending aortic rupture post-dissection aneurysm). One brachiocephalic trunk branch was relined 8 days post-op but target vessel patency remained 100%. Conclusion: f/bEVARA are feasible options for the management of aortic arch pathology with an acceptable short-term mortality. Cerebrovascular events are the main comorbidity. Peri-operative events were notably experienced in fEVARA, with grafts comprising a fenestration and scallop morphology, and also in chronic dissection cases. Disclosure: Nothing to disclose

TAA 20. Analysis for Deteriorating Development of Aortic Dissection After Thoracic Endovascular Aortic Repair

As the preferred method for treatment of type B dissection, thoracic endovascular aortic repair (TEVAR) has been recognized by clinicians for its efficacy compared with open surgery. However, some serious complications still occur after TEVAR, such as progression of anterograde tear of the dissection, formation of new intimal rupture, rupture of the dissection aneurysm, and retrograde type A dissection (RTAD). Although the incidence rate of these complications is not high, the consequence is serious and should cause the clinician's attention. A retrospective analysis was performed of 53 patients with type B aortic dissection treated with TEVAR from January 2009 to December 2018. Complications occurred in six cases after TEVAR, with an incidence of 11.3%. RTAD occurred in two cases, and one patient died 2 hours after TEVAR. Another one was found by computed tomography angiography re-examination 2 weeks after TEVAR, and this patient's condition was stable after conservative treatment, such as blood pressure control. Two patients suffered from ruptured dissecting aneurysm of the descending arch, and one died within 1 hour after TEVAR; this patient was diagnosed with Marfan syndrome preoperatively. In the other patient, ruptured dissecting aneurysm occurred 5 hours after TEVAR; the patient survived with first-aid measures, including 1200-mL blood transfusion, and finally recovered by thoracic closed drainage and thoracoscopic hematoma removal. Two patients presented with progressive anterograde intimal tearing, and their condition was stable after conservative treatment. Some factors of postoperative complications of TEVAR are related to the patient's condition, such as Marfan syndrome. Uncontrolled severe hypertension was significantly associated with continued progress of the dissection or rupture of the dissected aneurysm. The occurrence of RTAD is related to the anchorage area near the proximal portion of the stent. The progression of anterograde intimal tear is related to the lesion of the endarterium at the distal end of the stent, such as significant narrowing of the true lumen. Materials and design of the stent also have an impact on the occurrence of complications after TEVAR. In addition, it is important to avoid iatrogenic injury during the endovascular procedure.

Retrograde Type A Dissection after Ascending Aorta Involved Endovascular Repair and Its Surgical Repair with Stented Elephant Trunk

Retrograde type A dissection (RTAD) is a serious complication after ascending aorta involved endovascular repair (AAIER). We here report our surgical approach to this serious complication. From July 2011 to July 2014, 8 RTADs after AAIER patients received surgical repair in our institution. Data of these RTAD patients were retrospectively collected for further analysis. All patients received urgent surgical repair based on the stented elephant trunk technique. We took 2 different ways to handle the previous stent during operation. In patients who had a prior hybrid aortic repair, we removed the proximal part of the stent while the distal part was left in place. In patients who had prior ascending aorta stent implantation (AASI), the stent was totally removed. The mean age of the patients was 57.6±11.9years. Regarding the index intervention, 2 patients received hybrid aortic repair and 6 patients received AASI. In patients who received AASI, 1 patient underwent simultaneous thoracic endovascular aortic repair (TEVAR) and another patient received simultaneous chimney technique in innominate artery and left common carotid artery combined with bypass from left subclavian artery to left common carotid artery to cure the type I endoleak induced by the previous implanted TEVAR stent. All patients received a new elephant trunk implantation during surgical repair. The mean cardiopulmonary bypass, selective cerebral perfusion, and aortic cross-clamp time were 172.1±13.3, 40.8±4.2, and 121.8±11.4min, respectively. The mean intensive care unit time was 7.8±3.4days. Two patients (25.0%) experienced transient neurologic dysfunction and recovered completely before discharge. In-hospital death rate was 12.5% (1 of 8). The mean follow-up time was 17.1±9.5months. No late deaths or complications occurred during follow-up. AAIER especially AASI used in aortic dissection treatment should be seriously considered since RTAD might occur. Our study indicated that surgical repair with stented elephant trunk was feasible and according to the cause of RTAD, different surgical strategies should be taken to manage the stent.

Finite Element Analysis for Type B Aortic Dissection Treated with Two Types of Stent Grafts

Retrograde type A dissection (RTAD) and stent graft-induced new entry (SINE) is one of the most common post-TEVAR complications, and is defined as a new tear caused by the stent-graft itself (Dong Z.H. et al., 2009). Presumably, the mechanical action and potential damage of stent-graft to the aorta is related to the stent-graft and the anchoring position, mainly from two aspects: (1) The metal skeleton functions to fix the whole support to the wall of the aorta because it is self-inflating and strong in radial force. (2) After implantation, the stent-graft is bent into the arch like a bent spring, with a tendency to be straight. This may result in elastic recoil force to the aortic wall. This study investigated the occurring reasons of new lesions from the biomechanical and mechanobiological view when stent-grafts were implanted into the true lumen to treat an aortic dissection.