A systematic review of mid-term outcomes of thoracic endovascular repair (TEVAR) of chronic type B aortic dissection

Aortic diameter remodeling after frozen elephant trunk as a predictor of early outcomes in thoracoabdominal aortic repair

OBJECTIVE

Patients who underwent previous frozen elephant trunk implantation for Stanford type A aortic dissection remain at risk for secondary intervention due to unsuccessful distal aortic remodeling. We aimed to investigate the impact of distal aortic remodeling on early outcomes in patients who underwent 2-stage thoracoabdominal aortic repair.

METHODS

A total of 106 patients who previously underwent frozen elephant trunk implantation and thoracoabdominal aortic repair between October 2014 and December 2022 were enrolled in this study. The extent of distal aortic remodeling was evaluated, including aortic diameter, area ratio of the false lumen/aortic lumen, and patency of the false lumen at 3 levels of the aorta. Logistic regression analyses were performed to investigate the risk factors for early outcomes.

RESULTS

The aortic diameter at the distal frozen elephant trunk was significantly larger in patients who died early than in surviving patients (79.19 ± 22.89 mm vs 46.84 ± 19.17 mm, respectively, adjusted P = .001). The optimal cutoff value for the aortic diameter at the distal frozen elephant trunk was 60 mm. Patients with an aortic diameter 60 mm or more at the distal frozen elephant trunk had worse early outcomes (P < .05), including prolonged intubation, early death, and postoperative complications. The aortic diameter at the distal frozen elephant trunk was identified as a significant risk factor for early death in patients undergoing thoracoabdominal aortic repair.

CONCLUSIONS

Patients undergoing thoracoabdominal aortic repair with an aortic diameter 60 mm or more at the distal frozen elephant trunk have worse early outcomes. Moreover, an aortic diameter at the distal frozen elephant trunk is a significant risk factor for early death in patients undergoing thoracoabdominal aortic repair.

Safe and favorable prognosis of thoracic endovascular aortic repair for the low-risk patients with non-acute type B aortic dissection

Objective

Preemptive thoracic endovascular aortic repair (TEVAR) has the potential to improve the prognosis of Stanford type B aortic dissection (TBAD), however it is important to determine whether it could be safely performed as a prophylactic treatment. This study aimed to determine the short- and long-term outcomes of preemptive TEVAR for uncomplicated TBAD with a small aortic aneurysm.

Design

Retrospective multicenter analysis.

Methods

We analyzed 212 patients with medically treated uncomplicated subacute TBAD between July 2004 and October 2019 in two Japanese academic centers. The short- and long-term prognosis of patients who underwent preemptive TEVAR and the changes in aortic diameter over time after TEVAR were analyzed. Aorta-related complications, aortic-related death and postoperative complications were recorded and analyzed. Analysis was performed on an intension-to-treat basis.

Results

During follow-up, patients were divided into two groups: optimal medical treatment [OMT; n = 185 (87%)] and preemptive TEVAR [n = 27 (13%)]. In all cases, aortic enlargement was the reason for therapeutic intervention in the preemptive TEVAR group. Propensity score matching yielded a cohort of 27 control patients with OMT (group A) and 27 patients who underwent preemptive TEVAR (group B). Preoperative characteristics were similar between groups. In group B, only one patient developed type A dissection at a late stage and died from aortic rupture. Freedom from aortic-related death at 1/5/10 years was 100%/92%/92% in group B. Overall growth (mm/year) of max aorta was significantly smaller in the TEVAR group than in the control group (-3.7 ± 2.9 vs. 0.4 ± 5.6, p < 0.01), and the diameter of the false lumen was reduced (-8 ± 4.8 vs. -1.3 ± 8.0, p < 0.001).

Conclusions

Short- and long-term outcomes of TEVAR for uncomplicated TBAD with a small aortic aneurysm were excellent, with few postoperative complications. After TEVAR, aortic remodeling was observed in the short term, suggesting that it may contribute to the prevention of aortic-related death due to rupture.

Deep Learning Prediction for Distal Aortic Remodeling After Thoracic Endovascular Aortic Repair in Stanford Type B Aortic Dissection

PURPOSE

This study aimed to develop a deep learning model for predicting distal aortic remodeling after proximal thoracic endovascular aortic repair (TEVAR) in patients with Stanford type B aortic dissection (TBAD) using computed tomography angiography (CTA).

METHODS

A total of 147 patients with acute or subacute TBAD who underwent proximal TEVAR at a single center were retrospectively reviewed. The boundary of aorta was manually segmented, and the point clouds of each aorta were obtained. Prediction of negative aortic remodeling or reintervention was accomplished by a convolutional neural network (CNN) and a point cloud neural network (PC-NN), respectively. The discriminatory value of the established models was mainly evaluated by the area under the receiver operating characteristic curve (AUC) in the test set.

RESULTS

The mean follow-up time was 34.0 months (range: 12-108 months). During follow-up, a total of 25 (17.0%) patients were identified as having negative aortic remodeling, and 16 (10.9%) patients received reintervention. The AUC (0.876) by PC-NN for predicting negative aortic remodeling was superior to that obtained by CNN (0.612, p=0.034) and similar to the AUC by PC-NN combined with clinical features (0.884, p=0.92). As to reintervention, the AUC by PC-NN was significantly higher than that by CNN (0.805 vs 0.579; p=0.042), and AUCs by PC-NN combined with clinical features and PC-NN alone were comparable (0.836 vs 0.805; p=0.81).

CONCLUSION

The CTA-based deep learning algorithms may assist clinicians in automated prediction of distal aortic remodeling after TEVAR for acute or subacute TBAD.

CLINICAL IMPACT

Negative aortic remodeling is the leading cause of late reintervention after proximal thoracic endovascular aortic repair (TEVAR) for Stanford type B aortic dissection (TBAD), and possesses great challenge to endovascular repair. Early recognizing high-risk patients is of supreme importance for optimizing the follow-up interval and therapy strategy. Currently, clinicians predict the prognosis of these patients based on several imaging signs, which is subjective. The computed tomography angiography-based deep learning algorithms may incorporate abundant morphological information of aorta, provide with a definite and objective output value, and finally assist clinicians in automated prediction of distal aortic remodeling after TEVAR for acute or subacute TBAD.

Comparison of branched, fenestrated, and parallel strategies for endovascular treatment of thoracoabdominal aortic pathologies involving visceral regions

Purpose

To compare the long-term efficacy of the parallel stent graft (PSG), fenestrated stent graft (FSG), and branched stent graft (BSG) techniques to treat thoracoabdominal aortic pathologies.

Materials and methods

In total, 291 patients with thoracic aortic aneurysm (TAA) and dissection (TAD) involving visceral arteries who underwent PSG (n = 85; 15 TAA and 70 TAD), FSG (n = 107; 47 TAD and 60 TAA), or BSG (n = 99; 37 TAD and 62 TAA) were included from multiple centers from January 2015 to December 2022, and a total of 1,108 visceral aortic branches were reconstructed.

Results

The average reconstruction time of each visceral aortic branch for FSG, BSG, and PSG is 27.5 ± 12.1, 23.2 ± 11.9, and 18.8 ± 11.8 min, respectively (P < 0.01). The free-from-endoleak rate at the last follow-up for FSG, BSG, and PSG was 86.9%, 91.9%, and 60.0%, respectively. The last follow-up patency rate for FSG, BSG, and PSG was 85.0%, 91.9%, and 94.1%, respectively. The average reconstruction price of each visceral aortic branch for FSG, BSG, and PSG was 41.40 ± 3.22 thousand RMB, 41.84 ± 3.86 thousand RMB, and 42.35 ± 4.52 thousand RMB, respectively (P = 0.24).

Conclusion

To treat the aortic pathologies involving the visceral segment, BSG had a lower endoleak rate and higher branch patency rate when compared with the FSG and PSG techniques. The expense of BSG was comparable to the other two techniques.

Long-term outcomes of primary surgical repair for communicating DeBakey IIIb chronic dissecting aortic aneurysm

Objective

This study aimed to evaluate the long-term outcomes of surgical strategies for communicating DeBakey IIIb chronic dissecting aortic aneurysm, considering the optimal primary surgical repair to prevent aortic events.

Methods

From 2002 to 2021, 101 patients with communicating DeBakey IIIb chronic dissecting aortic aneurysm who underwent surgical repair were categorized based on the primary surgical repair: 1-stage repair of thoracoabdominal aortic aneurysm (TAAAR) (n = 22) or staged repair, such as descending thoracic aneurysm repair (DTAR) (n = 43) or total arch replacement with elephant trunk implantation (TARET) (n = 25), and thoracic endovascular aortic repair (TEVAR) (n = 11). Early and late postoperative outcomes were compared among the groups.

Results

Early outcomes for TAAAR, DTAR, TARET, and TEVAR were associated with the incidence of stroke (9.1% vs 0% vs 4.0% vs 9.1%, respectively), spinal cord injury (13.6% vs 4.7% vs 8.0% vs 0%, respectively), and in-hospital mortality (9.1% vs 2.3% vs 0% vs 9.1%, respectively). During follow-up, the 10-year overall survival and 7-year aortic event-free rates for TAAAR, DTAR, TARET, and TEVAR were 61.8%, 71.6%, 21.5%, and 26.5% and 93.8%, 84.3%, 74.4%, and 51.4%, respectively. TAAAR had significantly higher overall survival (P = .05) and aortic event-free rates (P = .03) than TEVAR. TARET (hazard ratio, 2.27; P < .01) and TEVAR (hazard ratio, 3.40; P < .01) were independently associated with the incidence of aortic events during follow-up.

Conclusions

Considering the optimal primary surgical repair based on long-term outcomes, TEVAR was not a durable treatment option. Patient-specific TAAAR or DTAR should be considered rather than defaulting to minimally invasive primary repairs for all patients with communicating DeBakey IIIb chronic dissecting aortic aneurysm.

Acute Type B Aortic Dissection: Insights From a Single-Center Retrospective Experience Over 12 Years

INTRODUCTION

The treatment of acute type B aortic dissection (ATBAD) is currently a challenge for vascular surgeons, because of the early morbidity and mortality rates and the high risk of late aortic events up to 50% at 5 years. This study presents the initial outcomes of ATBAD treatment using optimal medical therapy alone or combined with proximal entry tear stent-graft coverage. Additionally, it provides an analysis of the evolution of the aortic diameter and its clinical consequences during the chronic phase in each group.

MATERIALS AND METHODS

Conducted as a retrospective, single-center study, we enrolled all consecutive ATBAD patients (n=130) treated between 2008 and 2020. The primary analysis studies the entire patient cohort based on their initial management approach, namely, medical treatment alone for uncomplicated ATBAD (n=67) or combined with stent-graft entry tear coverage (n=63). We also conducted a subgroup analysis to investigate factors associated with disease progression in the medical management group.

RESULTS

Median follow-up was 29.5 months. During this time aneurysmal evolution was observed in: 42.4% of cases in the medical group compared with 21.8% in the stent-graft group, primarily affecting the thoracic aorta. The stent-graft group exhibited significant aortic remodeling, with a decrease in false lumen (FL) and thoracic aortic diameters. Initial aortic diameter ≥40 mm and FL ≥22 mm were independent risk factors for aneurysmal degeneration. Five-year survival was consistent at 76.1% in both groups.

CONCLUSION

This study confirms the safety and efficacy of stent-graft entry tear coverage for ATBAD. Initial thoracic endovascular aortic repair (TEVAR) appears to reduce late aortic events by promoting aortic remodeling. Considering TEVAR's safety and potential to prevent late aortic complications, it may be considered for uncomplicated ATBAD patients with an initial aortic diameter ≥40 mm or an FL ≥22 mm.

CLINICAL IMPACT

This study validates the efficacy and safety of using endovascular stent grafts to seal the proximal entry tear in cases of acute type B aortic dissections, compared to optimal medical therapy. Aortic remodelling significantly benefits from endovascular stent graft coverage of the proximal entry tear. Given the heightened risk of late aortic events observed in the medical therapy cohort, there appears to be a necessity for including endovascular interventions in the management of uncomplicated acute type B aortic dissections, particularly when aortic diameter is ≥40 mm and false lumen diameter is ≥22 mm.

Long-term outcomes of thoracic endovascular aortic repair for chronic Stanford type B aortic dissection

OBJECTIVES

The aim of this study was to report the long-term outcomes of proximal thoracic endovascular aortic repair (TEVAR) for chronic Stanford type B aortic dissection (cTBAD).

METHODS

We retrospectively analyzed the clinical data of 48 cases of patients with cTBAD who underwent proximal TEVAR in Zhongshan Hospital Fudan University from January 2010 to September 2013. The preoperative and postoperative imaging examinations, overall survival rate, aortic-related survival rate, and freedom from reintervention rate data were collected to evaluate aortic remodeling and clinical outcomes. The enrolled patients received follow-up at 1, 3, 6, and 12 months following treatment and annually thereafter.

RESULTS

A total of 48 patients (mean age, 58.3 ± 10.6 years; men:women, 40:8) were included, of which 38 cases (79.2%) were uncomplicated dissection and 10 cases (20.8%) were complicated. The mean follow-up time was 48.7 ± 40 months (1-120 months). The mean time interval from the initial procedure to reintervention was 50.6 ± 32.7 months (11-98 months). The following changes were observed at preoperative versus last follow-up timepoints. Descending aortic level: true lumen, 19.2 ± 7.01 mm vs. 36.9 ± 9.53 mm (p < 0.001); false lumen, 30.47 ± 15.89 mm vs. 19.16 ± 15.33 mm (p < 0.001); maximum diameter, 49.67 ± 13.96 mm vs. 56.66 ± 14.95 mm (p = 0.018). Diaphragm level: true lumen, 16.24 ± 5.41 mm vs. 24.41 ± 8.04 mm (p < 0.001); false lumen, 12.37 ± 11.49 mm vs. 14.92 ± 12.25 mm (p = 0.196); and maximum diameter, 34 ± 7.81 mm vs. 38.04 ± 7.7 mm (p < 0.001). The freedom from reintervention rate was 81% in 5 years and 50.6% in 10 years. The overall 10-years survival rate was 83% (6 of 48), and the aortic-related survival rate was 92.3% (3 of 48).

CONCLUSIONS

TEVAR is a safe and effective proximal repair intervention for cTBAD that can reliably induce the positive remodeling of the descending aorta.

Trauma-Induced Thoracic Stent Graft Migration and Dissecting Aneurysm Rupture

Thoracic endovascular aortic repair (TEVAR) is widespread. We report a case of graft migration and dissecting aneurysm rupture after trauma. An 82-year-old man with a history of TEVARs for chronic type B aortic dissection had sudden dyspnea and hemoptysis after falling from a stationary bicycle. Enhanced computed tomography revealed graft migration, endoleak, and dissecting aneurysm rupture. TEVAR was repeated emergently, and he was discharged without complications. Blunt injury to the trunk of the body may cause graft migration and aortic rupture in the chronic phase after TEVAR. This report describes graft migration and rupture induced by trauma.

Long-term outcomes of thoracic endovascular aortic repair for the treatment of descending thoracic aortic aneurysms: a systematic review and meta-analysis

INTRODUCTION

We undertook a systematic review of the currently published literature on TEVAR for DTAAs and we combined the eligible studies into a meta-analysis with the intention of evaluating the efficacy and the long-term durability of this treatment option.

EVIDENCE ACQUISITION

A systematic search of the literature from January 2015 up to December 2022 was performed according to the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. For events during follow-up we calculated the incidence rates (IRs) with 95% confidence intervals (95% CIs) per 100 patient-years (p-ys) as the number of patients with outcome events occurring during the specific time period divided by the total number of p-ys.

EVIDENCE SYNTHESIS

A total of 4127 study titles were identified by the initial search strategy, of which 12 were considered eligible for inclusion in the meta-analysis. A Total of 1976 patients (62% male) were identified among the eligible studies. One-year survival was 90.1% (95% CI 86.3% to 93.0%), 3-year survival was estimated at 80.5% (95% CI 69.2% to 88.4%) and the 5-year survival was estimated at 73.2% (95%CI 64.3% to 80.5%) with significant heterogeneity among studies regarding these outcomes. Regarding freedom from reintervention analysis for 1 year and 5 years was 96.5% (95% CI 94.5% to 97.8%) and 85.4% (95% CI 56.7% to 96.3%) respectively. The pooled late complications IR per 100 p-ys was 55.0 (95% CI 39.1 to 70.9), whereas the pooled IR for late reinterventions per 100 p-ys was 21.2 (95% CI 26.0 to 87.5). Late type I endoleak was reported with a pooled IR of 26.7 per 100 p-ys (95% CI 19.8 to 33.6) and late type III endoleak with a pooled IR of 7.6 per 100 p-ys (95% CI 5.5 to 9.7).

CONCLUSIONS

TEVAR presents a safe and feasible solution for the treatment of DTAA with sustained long-term effectivity. Current evidence supports a satisfactory 5-year survival with low rates of reinterventions.

Risk Factors for Incomplete Aortic Remodeling With Stent-Assisted Balloon-Induced Intimal Disruption and Relamination in Aortic Dissection Repair for Complicated Aortic Dissection: Results of a Multicenter Study

PURPOSE

The STABILISE technique has extended the treatment of aortic dissection to the thoracoabdominal aorta to achieve complete aortic remodeling. The aim of this multicenter study was to analyze the short- and midterm anatomical results of the STABILISE technique.

MATERIALS AND METHODS

We retrospectively analyzed patients treated with the STABILISE technique for complicated aortic dissection at 3 French academic centers. The aortic diameter at different levels was measured preoperatively, postoperatively, and at 1 year.

RESULTS

Between 2018 and 2020, 58 patients, including 47 men (average patient age: 60±11 years), were treated for type B aortic dissection in 34 cases and residual aortic dissection after type A repair in 24 cases. Three (5.2%) patients died postoperatively. Complete aortic remodeling (false lumen thrombosis and complete reapposition of the intimal flap) was achieved in 45/55 patients (81.8%), and false lumen thrombosis in the thoracic aorta was achieved in 52/55 patients (94.5%). At 1 year, with a computed tomographic (CT) scan available for 98.2% (54/55) of patients, we observed a significant decrease in the maximal thoracic aortic diameter and a significant increase in the aortic diameter at the bare-stent level compared with the preoperative CT scan. Severe aortic angulation (p=0.024) was a risk factor for incomplete aortic remodeling and significantly increased the aortic diameter (p=0.032). Chronic aortic dissection was associated with an increased risk of incomplete aortic remodeling (p=0.002).

CONCLUSIONS

STABILISE for complicated aortic dissection results in false lumen thrombosis, complete reapposition of the intimal flap, and a decrease in the maximum aortic diameter in most cases. Incomplete reapposition of the intimal flap, which is more frequent in cases of chronic aortic dissection and severe aortic angulation, is a risk factor for a significant increase in the aortic diameter at the bare-stent level, and this risk justifies close follow-up and better patient selection.

CLINICAL IMPACT

STABILISE technique for complicated aortic dissection results in false lumen thrombosis, complete aortic remodeling and a decrease in the maximum aortic diameter in most cases. At the bare-stent level, incomplete reapposition of the intimal flap, more frequent in chronic aortic dissection and severe aortic angulation, is a risk factor for an increased aortic diameter. This finding justifies close follow-up and better patient selection; thus, the STABILISE technique should be used with care in chronic aortic dissection and severe aortic angulation.

One-Year Results of a Low-Profile Endograft in Acute, Complicated Type B Aortic Dissection

BACKGROUND

The safety and effectiveness of the RelayPro endograft (Terumo Aortic) was assessed for the treatment of acute, complicated type B aortic dissection (TBAD).

METHODS

A prospective pivotal trial analyzed a primary end point of all-cause mortality at 30 days. Secondary end points included technical success, major adverse events (disabling stroke, renal failure, and paraplegia/paralysis), endoleaks, patency, rupture, device integrity, false lumen perfusion, reinterventions, aortic expansion, and migration evaluated to 5 years.

RESULTS

The study involved 22 United States centers and enrolled 56 patients (mean age, 59.5 ± 11.4 years) from 2017 to 2021; of whom, 73.2% were men and 53.6% were African American. TBAD was complicated by malperfusion of the kidneys (51.8%), lower extremities (35.7%), and viscera (33.9%), and rupture (10.7%). Dissection extended proximally to zones 1/2 (14.3%) and zone 3 (78.6%) and distally to the iliac arteries (67.3%). Most procedures were percutaneous (85.5%). Technical success was 100%. Median hospitalization was 7 days (interquartile range, 5-12 days). All-cause mortality at 30 days was 1.8% (1 of 56; upper 95% CI, 8.2%; P < .0001). Seven major adverse events occurred in 6 patients (10.7%), consisting of paraplegia (n = 3), paraparesis (n = 2), disabling stroke (n = 1), and renal failure (n = 1). All paraplegia/paraparesis resolved with lumbar drainage. Kaplan-Meier analysis estimated a freedom from major adverse events of 89.1% at each interval from 30 days to 3 years. There was 1 endoleak (Type Ia), 2 retrograde dissections, and aortic diameter growth occurred in 2. There has been no rupture, fistula, component separation, patency loss, stenosis, kinking, twisting, bird beak, loss of device integrity, or fracture.

CONCLUSIONS

RelayPro is safe and effective in acute, complicated TBAD. Follow-up is ongoing to evaluate longer-term outcomes and durability.

Aortic Remodeling After Thoracic Endovascular Aortic Repair for Nonacute Uncomplicated Type B Aortic Dissection

BACKGROUND

Entry closure with thoracic endovascular aortic repair (TEVAR) for Stanford type B aortic dissection (TBAD) results in aortic remodeling recently. This study aimed to evaluate the relationship between aortic diameter or timing of surgical intervention from onset and remodeling after TEVAR for uncomplicated nonacute TBAD.

METHODS

Between April 2014 and December 2021, 83 consecutive patients underwent TEVAR for TBAD at our center. Forty patients with subacute and chronic uncomplicated TBADs with a patent false lumen, who could be followed up for at least 6 months, were included in this study. Indications for TEVAR included aortic diameter enlargement and preemptive treatment to prevent future aneurysmal changes in patients at risk of aortic diameter enlargement. Aortic remodeling was accessed, and data between the remodeling and nonremodeling groups were compared.

RESULTS

The technical success rate was 97.5%, with a type Ia endoleak remaining in 1 patient. No operative or in-hospital mortality occurred. Paraparesis occurred in only 1 patient (2.5%). Follow-up was completed at a median of 53.5 months. Late death occurred in 3 cases, but there were no aortic-related deaths. Late aortic remodeling was achieved in 22 patients (55%). The preoperative maximum aortic diameter (PMAD) in the thoracic aortic region was 51.5 mm in the nonremodeling group, significantly larger than 42.5 mm in the remodeling group (P < 0.0001). The cutoff value of the PMAD for predicting aortic remodeling was 45 mm (area under the curve, 0.917; P = 0.028). The remodeling group had an earlier time from onset to intervention than the nonremodeling group, with a cutoff value of 6.3 months (area under the curve, 0.743; P = 0.021).

CONCLUSIONS

TEVAR for nonacute uncomplicated TBAD resulted in a late aortic remodeling rate of 55%. This study suggested that a PMAD of >45 mm or a period >6.3 months between dissection onset and surgery hinders aortic remodeling after TEVAR.

A Comparison of Retrospective ECG-Gated CT and Surgical or Angiographical Findings in Acute Aortic Syndrome

The best cardiac phases in retrospective ECG-gated CT for detecting an intimal tear (IT) in aortic dissection (AD) and an ulcer-like projection (ULP) in an intramural hematoma (IMH) have not been established. This study aimed to compare the detection accuracy of diastolic-phase and systolic-phase ECG-gated CT for IT in AD and ULP in IMH, with subsequent surgical or angiographical confirmation as the reference standard.In total, 81 patients (67.6 ± 11.8 years; 41 men) who underwent emergency ECG-gated CT and subsequent open surgery or thoracic endovascular aortic repair for AD (n = 52) or IMH (n = 29) were included. The accuracies of detecting IT and ULP were compared among only diastolic-phase, only systolic-phase, and both diastolic-phase and systolic-phase methods of retrospective ECG-gated CT; surgical or angiographical findings were used as the reference standard. The detection accuracy for IT and ULP using only diastolic-phase, only systolic-phase, and both diastolic-phase and systolic-phase methods of ECG-gated CT was 93% [95% CI: 87-97], 94% [95% CI: 88-97], and 95% [95% CI: 90-97], respectively. There were no significant differences in detection accuracy among the 3 acquisition methods (P = 0.55). Similarly, there were no significant differences in the accuracy of detecting IT in AD (P = 0.55) and ULP in IMH (P > 0.99) among only diastolic-phase, only systolic-phase, and both diastolic- and systolic-phase ECG-gated CT.Retrospective ECG-gated CT for detecting IT in AD and ULP in IMH yields highly accurate findings. There were no significant differences seen among only diastolic-phase, only systolic-phase, and both diastolic-phase and systolic-phase ECG-gated CT.

Type Ib endoleak repaired with a thoracic endovascular graft inside previous visceral debranching bypass in a patient with chronic type B aortic dissection

We present the case of a patient with chronic type B aortic dissection with a previous iliac to visceral debranching graft and thoracoabdominal endograft who, because of a type Ib endoleak and aortic diameter enlargement, required a complex solution involving placement of a thoracic endovascular graft inside a Dacron graft with a 180° curved shape in three-stage surgery. At 9 months of follow-up, he had no evidence of type I endoleaks, and the aortic diameter had decreased.

Efficacy of left subclavian artery revascularization strategies during thoracic endovascular aortic repair in patients with type B dissection: A single-center experience of 105 patients

Background

Left subclavian artery (LSA) revascularization during thoracic endovascular aortic repair (TEVAR) is necessary to reduce postoperative complications in patients with Stanford type B aortic dissection and an insufficient proximal anchoring area. However, the efficacy and safety of different LSA revascularization strategies remain unclear. Here, we compared these strategies to provide a clinical basis for selecting an appropriate LSA revascularization method.

Methods

In this study, we included 105 patients with type B aortic dissection who were treated using TEVAR combined with LSA reconstruction in the Second Hospital of Lanzhou University from March 2013 to 2020. They were divided into four groups according to the method used for LSA reconstruction, namely, carotid subclavian bypass (CSB; n = 41), chimney graft (CG; n = 29), single-branched stent graft (SBSG; n = 21), and physician-made fenestration (PMF; n = 14) groups. Finally, we collected and analyzed the baseline, perioperative, operative, postoperative, and follow-up data of the patients.

Results

The treatment success rate was 100% in all the groups, and CSB + TEVAR was the most commonly used procedure in emergency settings compared with the other three procedures (P &lt; 0.05). The estimated blood loss, contrast agent volume, fluoroscopic time, operation time, and limb ischemia symptoms during the follow-up were significantly different in the four groups (P &lt; 0.05). Pairwise comparison among groups indicated that the estimated blood loss and operation time in the CSB group were the highest (adjusted P &lt; 0.0083; P &lt; 0.05). The contrast agent volume and fluoroscopy duration were the highest in the SBSG groups, followed by PMF, CG, and CSB groups. The incidence of limb ischemia symptoms was the highest in the PMF group (28.6%) during the follow-up. The incidence of complications (except limb ischemia symptoms) during the perioperative and follow-up periods was similar among the four groups (P &gt; 0.05) The median follow-up time of CSB, CG, SBSG, and PMF groups was significantly different (P &lt; 0.05), and the CSB group had the longest follow-up.

Conclusion

Our single-center experience suggested that the PMF technique increased the risk of limb ischemia symptoms. The other three strategies effectively and safely restored LSA perfusion in patients with type B aortic dissection and had comparable complications. Overall, different LSA revascularization techniques have their advantages and disadvantages.

The Caged Knickerbocker: A Novel Modification to Targeted False Lumen Management in Complex Aortic Dissection

INTRODUCTION

Targeted false lumen management has been described for complex presentations of aortic dissection. The "Knickerbocker" technique is often referenced and includes dilating a focal portion of an oversized endograft in the true lumen to purposefully rupture the false lumen septum, but at the expense of increased risk for visceral propagation and malperfusion. This case series describes a novel modification of the Knickerbocker technique by caging the distal end of the endograft prior to focal dilation.

METHODS

A retrospective chart review was conducted at a tertiary academic center from 2018-2020. Patients were included if they had a history or current presentation of aortic dissection and underwent a Caged Knickerbocker (CKB) repair. Data were collected to include demographics, indications for repair, technical success, perioperative outcomes, hospital course, mortality, and further aortic interventions.

RESULTS

Five patients were included in our evaluation. Four patients (80%) presented with chronic Type B aortic dissection (cTBAD) and concomitant aneurysmal degeneration of the thoracic aorta; 1 patient (20%) presented with an acute rupture secondary to cTBAD. Three patients (60%) had previous aortic repairs, 2 of which were for Type A Aortic Dissection that additionally required redo sternotomy and total arch replacement prior to CKB. CKB was technically successful in all cases with no peri-operative complications. Two (40%) patients required further aortic intervention due to aneurysmal degeneration.

CONCLUSION

Achieving complete false lumen thrombosis is a considerable challenge when managing complex aortic dissections. Our data demonstrate the technical feasibly and early successful outcomes with the CKB approach. Importantly, CKB facilitates future distal extension into the para-visceral aorta in cases of complex thoracoabdominal aortic aneurysms. Further research should focus on discerning individual patients who will benefit from targeted false lumen management and compare outcomes between different approaches.

Management of acute aortic syndrome with evolving individualized precision medicine solutions: Lessons learned over two decades and literature review

Background

Thoracoabdominal acute aortic syndrome is associated with high morbidity and mortality. We aim to scrutinize our evolving strategies for acute aortic syndrome (AAS) management using minimally invasive and adaptive surgical techniques over two decades.

Methods

This is a longitudinal observational study at our tertiary vascular centre from 2002 to 2021. Out of 22,349 aortic referrals, we performed 1,555 aortic interventions over twenty years. Amongst 96 presented with symptomatic aortic thoracic pathology, 71 patients had AAS. Our primary endpoint is combined aneurysm-related and cardiovascular-related mortality.

Results

There were 43 males and 28 females (5 Traumatic Aortic Transection (TAT), 8 Acute Aortic Intramural Hematoma (IMH), 27 Symptomatic Aortic Dissection (SAD) and 31 Thoracic Aortic Aneurysm (TAA) post-SAD) with a mean age of 69. All the patients with AAS received optimal medical therapy (OMT), but TAT patients underwent emergency thoracic endovascular aortic repair (TEVAR). Fifty-eight patients had an aortic dissection, of which 31 developed TAA. These 31 patients with SAD and TAA received OMT initially and interval surgical intervention with TEVAR or sTaged hybrId sinGle lumEn Reconstruction (TIGER). To increase our landing area, we performed a left subclavian chimney graft with TEVAR in twelve patients. The average follow-up duration was 78.2 months, and eleven patients (15.5%) had combined aneurysm and cardiovascular-related mortality. Twenty-six percentage of the patients developed endoleaks (EL), of which 15% required re-intervention for type II and III. Four patients who had paraplegia (5.7%) and developed renal failure died. None of our patients had a stroke or bowel ischaemia. Twenty patients had OMT, eight of these were patients with acute aortic hematoma, and all eight died within 30 days of presentation.

Conclusion

Acute aortic hematoma is a sinister finding, which must be closely monitored, and consideration is given to early intervention. Paraplegia and renal failure result in an increased mortality rate. TIGER technique with interval TEVAR has salvaged complex situations in young patients. Left subclavian chimney increases our landing area and abolishes SINE. Our experience shows that minimally invasive techniques could be a viable option for AAS.

Bicolor K-edge spectral photon-counting CT imaging for the diagnosis of thoracic endoleaks: A dynamic phantom study

PURPOSE

The purpose of this study was to investigate the feasibility of identifying and characterizing the three most common types of endoleaks within a thoracic aorta aneurysm model using bicolor K-edge imaging with a spectral photon-counting computing tomography (SPCCT) system in combination with a biphasic contrast agent injection.

MATERIALS AND METHODS

Three types of thoracic endoleaks (type 1, 2 and 3) were created in a dynamic anthropomorphic thoracic aorta phantom. Protocol consisted in an injection of an iodinated contrast material followed 80 seconds after an injection of a gadolinium-based contrast agent (GBCA). The phantom was scanned using a clinical prototype SPCCT during bicolor phase imaging consisting in an early distribution of GBCA and a late distribution of iodine. Conventional and spectral images were reconstructed for differentiating between the contrast agents and measuring their respective attenuation values and concentrations inside and outside the stent graft.

RESULTS

Conventional images failed to provide specific dynamic imaging contrast agents in the aneurysmal sac and outside the stent graft while spectral images differentiated their specific distribution. In type 1 and 3 thoracic endoleaks, GBCA concentration was measured outside the stent graft at 6.1 ± 3.7 (standard deviation [SD]) mg/mL and 6.0 ± 4.0 (SD) mg/mL, respectively, in favor of an early blood flow. In type 2 thoracic endoleak, iodine was measured outside the stent graft at 24.3 ± 5.5 (SD) mg/mL in favor of a late blood flow in the aneurysmal sac.

CONCLUSION

Bicolor K-edge imaging enabled SPCCT allows a bicolor characterization of thoracic aorta endoleaks in a single acquisition in combination with a biphasic contrast agent injection.

Balloon Inducted Re-Lamination and False lUmen Thrombosis in Chronic Type B Aortic Dissection: Technique and Long-Term Results

BACKGROUND

To evaluate the safety, feasibility, and effectiveness of the BAlloon Inducted re-Lamination and false lUmen Thrombosis (BAILOUT) as a simple technique to address the retrograde false lumen (FL) perfusion and subsequent aneurysmatic degeneration of the thoracic aorta due to a stent-graft crimped in a small true lumen in chronic Type B dissections.

METHODS

An observational, retrospective, single-center study analyzing a nonconsecutive cohort of 8 patients affected by chronic type B aortic dissections already treated with thoracic endovascular repair and with an FL lumen backflow corrected with BAILOUT between 2006 and 2020. After a standard distal extension of the previously implanted graft, the distal end of the graft area was ballooned to completely rupture the dissection lamella to relaminate the aorta hindering the FL backflow. Computed tomography was routinely performed within the first postoperative week before discharge and then at 3 months, at 6 months, and yearly thereafter. The technical and clinical success rates were analyzed. Primary outcomes were safety and feasibility of the technique, secondary ones included FL thrombosis evaluation, and total aortic diameter analysis at the above-defined levels during the follow-up. Safety was defined if clinical success was reached. Feasibility was intended as technical success obtention.

RESULTS

The technical and clinical success achieved was 100% with the complete interruption of FL backflow stating the safety and feasibility of the BAILOUT technique. No early procedure reinterventions were recorded and during a median follow-up of 62.5 months [interquartile range 43.2-94.1], only 1 death unrelated to the procedure was recorded. Freedom from aortic-related adverse events at 1 month, 3 months, 1 year, 5, and 7 years was 87.5%, 62.5%, 62.5%, 62.5%, and 62.5%, respectively. During the follow-up, no one increment of the diameter of the thoracic aorta was documented and all the patients at 3 years of computed tomography angiography showed a complete FL thrombosis.

CONCLUSIONS

The BAILOUT technique demonstrates to be safe and feasible in this small cohort of patients as a simple and quick way to overcome the issue of FL backflow in chronic type B dissection. Small cohort and retrospective designs were limitations of the study.

Long-Term Outcomes of Chronic Type B Aortic Dissection Treated by Thoracic Endovascular Aortic Repair

Background The treatment of chronic type B aortic dissection by thoracic endovascular aortic repair has some challenges, and its long-term outcomes remain unclear. This study aimed to analyze the 5-year clinical outcomes of thoracic endovascular aortic repair of chronic type B aortic dissection, compare the differences between patients with and without adverse aortic events (AAEs), and identify risk factors for AAEs. Methods and Results Patients who underwent thoracic endovascular aortic repair of chronic type B aortic dissection from January 2009 to June 2017 were retrospectively enrolled. The primary end points were AAEs, including aorta-related death, procedural complications, and disease progression requiring reintervention. Clinical outcomes were described at the 5-year follow-up visit. The secondary end point was the comparison of the results between patients with and without AAEs. Univariable and multivariable logistic analyses were used to identify potential risk factors for AAEs. A total of 214 patients were enrolled. AAEs occurred in 46 (21.5%) patients. Compared with patients without AAEs, those with AAEs had higher rates of residual type A aortic dissection (26.1% versus 4.2%, P<0.001) and aortic diameter ≥5.5 cm (69.6% versus 11.3%, P<0.001), and a lower rate of complete false lumen thrombosis (23.9% versus 89.9%, P<0.001). Meanwhile, the median interval from symptom onset to intervention was longer in patients with AAEs (26 months versus 12 months, P=0.004). Partial or no false lumen thrombosis (adjusted odds ratio [AOR], 14.71 [95% CI, 5.67-38.14; P<0.001]) and aortic diameter ≥5.5 cm (AOR, 10.16 [95% CI, 3.86-26.73; P<0.001]) were identified as independent risk factors for AAEs. Conclusions While thoracic endovascular aortic repair of chronic type B aortic dissection might be challenging in some cases, its long-term outcomes appeared promising as this treatment was effective in preventing catastrophic aortic events. Patients with AAEs showed higher rates of residual type A aortic dissection and aortic diameter ≥5.5 cm, a lower rate of complete false lumen thrombosis, and a longer median interval from symptom onset to intervention. Failure of complete false lumen thrombosis and an aortic diameter ≥5.5 cm were predictors of AAEs.

Chronic Thoracic Aortic Dissection: How to Treat, When to Intervene

Thoracic aortic dissection (AD) is associated with increased morbidity and mortality. Acute aortic syndrome is the first presentation of the disease in most cases. While acute AD management follows concrete guidelines because of its urgent and life-threatening nature, chronic AD is usually overlooked, although it concerns a wide spectrum of patients surviving an acute event. Acute AD survivors ultimately enter a chronic aortic disease course. Patients with chronic thoracic AD (CTAD) require lifelong surveillance and a proportion of them may present with symptoms and late complications demanding further surgical or endovascular treatment. However, the available data concerning the management of CTAD is sparse in the literature. The management of patients with CTAD is challenging as far as determining the best medical therapy and deciding on intervention are concerned. Until recently, there were no guidelines or recommendations for imaging surveillance in patients with chronic AD. The diagnostic methods for imaging aortic diseases have been improved, while the data on new endovascular and surgical approaches has increased significantly. In this review, we summarize the current evidence in the diagnosis and management of CTAD and the latest recommendations for the surgical/endovascular aortic repair of CTAD.

[Chronic type B aortic dissection-what to do?]

BACKGROUND

Chronic type B aortic dissection requires optimal medical therapy. However, secondary complications like organ or extremity malperfusion or development of aneurysmal dilatation require interventional therapy.

OBJECTIVES

Presentation of different endovascular treatment options for complications of chronic type B aortic dissection.

MATERIALS AND METHODS

Analysis of current literature with regard to indications, techniques, results, and differential indications of interventional techniques for the treatment of chronic type B aortic dissection complications.

RESULTS

Endovascular implantation of an aortic stent graft is interventional standard therapy for treatment of aneurysmal dilatation of the aorta following type B dissection. Technical problems are the proximal and distal landing zones and the treatment of persistent flow in the false lumen.

CONCLUSION

Endovascular treatment of chronic complicated type B aortic dissection is increasingly used compared to open surgical treatment because not only are more complex stent grafts (fenestrated and branched devices) available but also because of newly developed techniques for effective occlusion of flow in the false lumen (e.g., candy plug).

Model-Based Fluid-Structure Interaction Approach for Evaluation of Thoracic Endovascular Aortic Repair Endograft Length in Type B Aortic Dissection

Thoracic endovascular aortic repair (TEVAR) is a commonly performed operation for patients with type B aortic dissection (TBAD). The goal of TEVAR is to cover the proximal entry tear between the true lumen (TL) and the false lumen (FL) with an endograft to induce FL thrombosis, allow for aortic healing, and decrease the risk of aortic aneurysm and rupture. While TEVAR has shown promising outcomes, it can also result in devastating complications including stroke, spinal cord ischemia resulting in paralysis, as well as long-term heart failure, so treatment remains controversial. Similarly, the biomechanical impact of aortic endograft implantation and the hemodynamic impact of endograft design parameters such as length are not well-understood. In this study, a fluid-structure interaction (FSI) computational fluid dynamics (CFD) approach was used based on the immersed boundary and Lattice–Boltzmann method to investigate the association between the endograft length and hemodynamic variables inside the TL and FL. The physiological accuracy of the model was evaluated by comparing simulation results with the true pressure waveform measurements taken during a live TEVAR operation for TBAD. The results demonstrate a non-linear trend towards increased FL flow reversal as the endograft length increases but also increased left ventricular pulsatile workload. These findings suggest a medium-length endograft may be optimal by achieving FL flow reversal and thus FL thrombosis, while minimizing the extra load on the left ventricle. These results also verify that a reduction in heart rate with medical therapy contributes favorably to FL flow reversal.

False Lumen Flow Assessment by Magnetic Resonance Imaging and Long-Term Outcomes in Uncomplicated Aortic Dissection

BACKGROUND

Despite the absence of clinical complications after an acute aortic dissection (AD) with persistent patent false lumen (FL), a high risk for clinical events may persist.

OBJECTIVES

The aim of this study was to assess the natural evolution of noncomplicated AD and ascertain whether different FL flow patterns by magnetic resonance imaging (MRI) have independent prognostic value for AD-related events beyond established morphologic parameters.

METHODS

One hundred thirty-one consecutive patients, 78 with surgically treated type A dissections and 53 with medically treated type B dissections, were followed up prospectively after acute AD with persistent patent FL in the descending aorta. Maximum aortic diameter, true lumen compression, entry tear, and partial FL thrombosis by computed tomography were assessed. Systolic antegrade true lumen and FL flow volumes and diastolic antegrade and retrograde flows were analyzed by MRI during the first year after AD.

RESULTS

After a median follow-up period of 8.0 years (IQR: 4.6-10.9 years), 43 patients presented aorta-related events (25 died and 18 required endovascular treatment). FL systolic antegrade flow ≥30% with respect to total systolic antegrade flow and retrograde diastolic flow ≥80% with respect to total diastolic FL flow were predictors of aortic events. In multivariate analysis, aortic diameter >45 mm (HR: 2.91), type B dissection (HR: 2.44), and MRI flow pattern (HR: 16.87) were independent predictors of AD-related events.

CONCLUSIONS

High systolic antegrade flow volume in the FL with significant diastolic retrograde flow assessed by MRI and aortic diameter >45 mm identify patients with higher risk for complications in whom more aggressive management would be indicated.

Methods and outcomes of endovascular false lumen embolization for thoracic aortic dissection

PURPOSE

To provide a contemporary review on endovascular false lumen (FL) embolization for thoracic aortic dissection (AD) and evaluate its early outcome.

METHODS

A systematic literature review on FL embolization for thoracic AD from January 2003 to December 2020 was performed under the instruction of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. Each article was analyzed using a standardized protocol including predefined demographic characteristics, perioperative mortality and major complications.

RESULTS

A total of 29 papers with 229 patients were included into the analysis. The methods of FL occlusion used were: the Candy-Plug technique, the knickerbocker technique, the "cork in the bottleneck" technique and direct FL embolization with combination of stent-grafts, coils, onyx, plugs and glue. FL embolization procedure was performed in 79 patients (34.5%) with type A AD and 150 (65.5%) with type B AD. FL direct embolization was the most frequently used technique, and it was applied in 198 (86.5%) patients. Candy-plug, knickerbocker and "cork in the bottleneck" techniques were used in 26 (11.4%), 3 (1.3%) and 2 (0.9%) patients, respectively. Technical success was achieved in all patients except one (228/229, 99.6%) in which implantation of a stent to celiac trunk was not possible. There were four hospital deaths (1.7%). Neurological complications occurred in 6 patients (2.6%), including 4 (1.7%) spinal cord ischemia and 2 (0.9%) ischemic stroke. There were 1 (0.4%) iatrogenic retrograde dissection and 2 (0.9%) renal failure reported. The mean duration of follow-up was 16.5 months. There were 21 deaths (9.3%) during follow-up, and 8 (3.6%) were aorta-related. Thirty-three (14.7%) secondary intervention were performed. Five patients (2.2%) required open completion thoracoabdominal procedure incorporating the stent-graft into the repair. Complete FL thrombosis was observed in 181 (80.4%) patients, 34 (15.1%) had partial thrombosis, and 10 (4.4%) had FL progression.

CONCLUSIONS

FL embolization of the distal thoracic aorta is a promising technique in a group of patients to promote FL thrombosis and aortic remodeling in thoracic aorta.

Differences in the Area of Proximal and Distal Entry Tears at CT Angiography Predict Long-term Clinical Outcomes in Aortic Dissection

Purpose

To identify entry tear variables that are related to adverse clinical events by using CT angiography (CTA) performed during the subacute phase of aortic dissection.

Materials and Methods

In this prospective study conducted from January 2000 to December 2013, participants with an aortic dissection with a patent false lumen and no comorbidities underwent CTA during the subacute phase. Participants were followed up for a survival analysis to assess the time to an adverse aortic event (AAE). The maximum aortic diameter (MAD), proximal and distal tear areas and difference between these areas, and partial false-lumen thrombosis were assessed by using Cox regression for adverse events.

Results

Seventy-two participants (mean age, 55 years ± 12 [standard deviation]; 55 men) were evaluated: 47 were surgically treated (type A aortic dissection) and 25 were medically treated (type B aortic dissection). Twenty-two participants had an AAE manifest during follow-up (9.22 years ± 5.78): There were 18 elective surgeries for aneurysmal degeneration, two emergent surgeries for acute aortic syndrome, and two aortic condition-related deaths. A categorical model composed of genetic aortic disease (GAD) (hazard ratio [HR], 3.4 [95% CI: 1.2, 9.9]; P = .02), MAD greater than 45 mm (HR, 6.1 [95% CI: 2.4, 15.8]; P < .001), and tear dominance (HR, 5.2 [95% CI: 2.1, 13]; P < .001), defined as an absolute tear area difference of greater than 1.2 cm², was used to stratify participants into three risk groups: low, without any risk factors (57% [41 of 72] and 7% [three of 41] had events); intermediate, with one risk factor (31% [22 of 72] and 50% [11 of 22] had events); and high, with two or more risk factors (13% [nine of 72] and 89% [eight of nine] had events; log rank P < .001).

Conclusion

Tear dominance demonstrated at CTA performed in the subacute phase of aortic dissection was related to long-term adverse events. Participants without GAD, dominant tears, or MAD greater than 45 mm had conditions that were safely managed with optimal medical treatment and imaging follow-up.Keywords: CT Angiography, Vascular, Aorta, Dissection Supplemental material is available for this article. © RSNA, 2021See also commentary by Fleischmann and Burris in this issue.

Endovascular versus open surgical repair for complicated chronic Type B aortic dissection

BACKGROUND

Type B aortic dissection can lead to serious and life-threatening complications such as aortic rupture, stroke, renal failure, and paraplegia, all of which require intervention. Traditionally, these complications have been treated with open surgery. Recently however, endovascular repair has been proposed as an alternative.

OBJECTIVES

To assess the effectiveness and safety of thoracic aortic endovascular repair versus open surgical repair for treatment of complicated chronic Type B aortic dissection (CBAD).

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, and AMED databases, as well as the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers, to 2 August 2021. We searched references of relevant articles retrieved through the electronic search for additional citations.

SELECTION CRITERIA

We considered all randomised controlled trials (RCTs) and controlled clinical trials (CCTs) assessing the effects of thoracic aortic endovascular repair (TEVAR) versus open surgical repair (OSR) for treatment of complicated chronic Type B aortic dissection (CBAD). Outcomes of interest were mortality (all-cause, dissection-related), neurological sequelae (stroke, spinal cord ischaemia/paresis-paralysis, vertebral insufficiency), morphological outcomes (false lumen thrombosis, progression of dissection, aortic diameters), acute renal failure, ischaemic symptoms (visceral ischaemia, limb ischaemia), re-intervention, and health-related quality of life.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all titles and abstracts identified by the searches to identify those that met the inclusion criteria. From title and abstract screening, we did not identify any trials (RCTs or CCTs) that required full-text assessment. We planned to undertake data collection and analysis in accordance with recommendations described in the Cochrane Handbook for Systematic Reviews of Interventions. We planned to assess the certainty of evidence using GRADE.

MAIN RESULTS

We did not identify any trials (RCTs or CCTs) that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

Due to lack of RCTs or CCTs investigating the effectiveness and safety of TEVAR compared to OSR for patients with complicated CBAD, we are unable to provide any evidence to inform decision-making on the optimal intervention for these patients. High-quality RCTs or CCTs addressing this objective are necessary. However, conducting such studies will be challenging for this life-threatening disease.

Surgical Strategy for Chronic Type B Dissecting Aortic Aneurysm to Prevent Aorta-Related Events

BACKGROUND

This study was aimed to evaluate the outcomes of performing open repair or thoracic endovascular aortic repair for chronic type B dissecting aortic aneurysm.

METHODS

From July 2004 to February 2019, 52 patients underwent surgery as open repair (n = 32) or endovascular repair (n = 20) for chronic type B dissecting aortic aneurysm. Replacement of the aorta was limited to the aneurysmal portion with or without reconstructing the visceral arteries or the segmental arteries. Stent grafts were deployed in the true lumen above the celiac artery to cover the primary entry for even DeBakey IIIb dissection.

RESULTS

Operative mortality and morbidity rates, including spinal cord ischemia incidence, did not differ between the groups. Operative mortality and morbidity rates, including spinal cord ischemia incidence, did not differ between the groups. In the endovascular repair group, 3 patients died due to rupture of residual false lumen in the early, and late postoperative follow-up. The 5-year rate of freedom from all-cause death, aorta-related death, and aorta-related event were 84% ± 6%, 94% ± 3% and 84% ± 6%. The endovascular repair was independently associated with all-cause death (hazard ratio [HR], 5.7; confidence interval [CI], 1.02-31.6; P = 0.04) and aorta-related event (HR, 30.9; CI 4.9-195.0; P < 0.001). In the open group, postoperative residual aortic diameter was an independent predictor of aorta-related events, and the threshold was 41 mm.

CONCLUSIONS

Open repair remains a better option than simple endovascular repair alone in DeBakey IIIb dissection, but the distal un-resected aortic portion over 41 mm was associated with late aortic events.

Endovascular therapies for Type B Aortic Dissection

Aortic dissection is a life-threatening condition resulting from a tear in the intimal layer of the aorta, requiring emergent diagnosis and prompt multi-disciplinary management strategy for best patient outcomes. While type A dissection involving ascending aorta is best managed surgically due to high early mortality, type B aortic dissection (TBAD) involving descending aorta generally has better outcomes with conservative management and medical therapy as primary strategy is favored. However, there has been a recent paradigm shift in management of TBAD due to late aneurysmal degeneration of TBAD increasing morbidity and mortality at longer-term. Late surgical intervention can be prevented by early endovascular intervention when combined with optimal medical therapy. In this narrative review, we explore available literature on different endovascular therapies for TBAD in different populations of patients.

Shrinkage of a Giant Type-B Dissecting Aneurysm Treated by Complete False Lumen Occlusion 20 Years after Presentation: A Case Report

In this study, we report the case of a 47-year-old female who presented with extensive acute type IIIb aortic dissection and cerebral infarction. At 69 years of age, dilatation of the descending aorta was noted to be more than 70 mm with compression of the left atrium. We performed endovascular repair with distal false lumen occlusion. However, further dilatation of the descending aorta with false lumen flow from the re-entry of the common carotid artery was detected. She subsequently underwent additional proximal false lumen occlusion by embolization at the aortic arch. A year later, as per her computed tomography angiography findings, appreciable shrinkage of the descending aorta without endoleakage was observed.

Predicting reintervention after thoracic endovascular aortic repair of Stanford type B aortic dissection using machine learning

OBJECTIVES

To construct models for predicting reintervention after thoracic endovascular aortic repair (TEVAR) of Stanford type B aortic dissection (TBAD).

METHODS

A total of 192 TBAD patients who underwent TEVAR were included; 68 (35.4%) had indications for reintervention. Clinical characteristics, aorta characteristics on pre- and postoperative computed tomography angiography, and aorta characteristics on immediate postoperative aortic digital subtraction angiography were collected. The least absolute shrinkage and selection operator (LASSO) regression was applied to identify the risk factors for reintervention. Eight classifiers were used for modeling. The models were trained on 100 train-validation random splits with a ratio of 2:1. The performance was evaluated by the receiver operating characteristic curve.

RESULTS

Seven predictors of reintervention were identified, including maximum false lumen diameter, aortic diameter measured at the level of approximately 15 mm distal to the left subclavian artery, aortic diameter measured at the level of the diaphragm, false lumen diameter measured at the level of the celiac artery, number of bare-metal and covered stents, number of bare-metal stents, and residual perfusion of the false lumen. Logistic regression (LR) yielded the highest performance, with an area under the curve of 0.802. A nomogram built for clinical use showed good calibration. The cutoff value for dividing patients into low- and high-risk subgroups was 0.413. Kaplan-Meier curves showed that the overall survival of high-risk patients was significantly shorter than that of low-risk patients (both p < 0.05).

CONCLUSION

Our nomogram could predict the reintervention after TEVAR in patients with TBAD, which may facilitate patient selection and surveillance strategies.

KEY POINTS

• Seven risk factors of reintervention after TEVAR of TBAD were identified for modeling. • Logistic regression performed best in predicting reintervention with an AUC of 0.802. • Patients with a high risk of reintervention had shorter OS than those with a low risk.

Computational Fluid Dynamics Simulations to Predict False Lumen Enlargement After Surgical Repair of Type-A Aortic Dissection

We aim to use computational fluid dynamics to investigate the hemodynamic conditions that may predispose to false lumen enlargement in this patient population. Nine patients who received surgical repairs of their type-A aortic dissections between 2017-2018 were retrospectively identified. Multiple contrast-enhanced post-operative CT scans were used to construct 3D models of aortic geometries. Computational fluid dynamics simulations of the models were run on a high-performance computing cluster using SimVascular - an open-source simulation package. Physiological pulsatile flow conditions (4.9 L/min) were used at the aortic true lumen inlet, and physiological vascular resistances were applied at the distal vascular ends. Exploratory analyses showed no correlation between rate of false lumen growth and blood pressure, immediate post-op aortic diameter, or the number of fenestrations (p = 0.2). 1-year post-operative CT scans showed a median false lumen growth rate of 4.31 (3.66, 14.67) mm/year Median (Interquartile range) peak systolic, mid-diastolic, and late diastolic velocity magnitudes were 0.90 (1.40); 0.10 (0.16); and 0.06 (0.06) cm/s respectively. Spearman's ranked correlations between fenestration velocity and 1-year false lumen growth rates were found to be statistically significant: Velocity magnitude at peak systolic (p = 0.025; rho = 0.75), mid diastolic (p = 0.025; rho = 0.75) and late diastolic phases of the cardiac cycle (p = 0.006; rho = 0.85). We have shown that false lumen growth is strongly correlated to fenestration flow velocity, which has potential implications for post-operative surveillance and risk stratification.

Comparative Outcome Analysis of N-Butyl Cyanoacrylate Embolization of the False Lumen Versus Thoracic Endovascular Aortic Repair in Aortic Dissection

PURPOSE

To evaluate the feasibility, safety, and effectiveness of N-butyl cyanoacrylate (NBCA) embolization for the treatment of aortic dissection.

MATERIALS AND METHODS

In this single-center retrospective study conducted from February 2003 to June 2019, NBCA embolization of an aortic false lumen was attempted in 12 patients (median age, 59 y; range, 41-68 y) and thoracic endovascular aortic repair (TEVAR) was performed in 53 patients (median age, 59 y; range, 37-70 y) for aortic dissection with one or more indications of persisting pain, malperfusion, rupture or impending rupture, maximal aortic diameter ≥ 55 mm, and/or rapid aortic enlargement. The main exclusion criterion for embolization was the presence of fast blood flow in the aortic false lumen on aortography. The efficacy of NBCA embolization and TEVAR was compared by evaluating technical and clinical outcomes, repeat intervention-free survival (RFS), and overall survival (OS).

RESULTS

Technical success was achieved in 11 of the 12 patients treated with NBCA embolization (91.7%), and clinical success was achieved in 9 of these 11 (81.8%). No significant difference was found between embolization and TEVAR in clinical success rates (embolization, 81.8%; TEVAR, 84.9%; P = .409) or procedure-related complications (embolization, 1 patient [8.3%]; TEVAR, 4 patients [7.5%]; P = .701). In addition, embolization showed comparable 5-y RFS (embolization, 82.5% ± 9.3; TEVAR, 85.5% ± 4.8; P = .641) and 5-y OS (embolization, 100%; TEVAR, 95.4% ± 3.2; P = .744) rates to TEVAR.

CONCLUSIONS

NBCA embolization of the false lumen in aortic dissection seems to be a safe and effective treatment modality for the closure of false lumen in selected patients.

Secondary Open Arch Operation After Prior Thoracic Endovascular Aortic Repair

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.

Current status on aortic endografts

Endovascular treatment has become widespread to treat aneurysmal disease, especially located in the aorta. The modern era of abdominal aortic aneurysm repair started between 1986 and 1991, and in the last 30 years, Endovascular Treatment for abdominal aortic aneurysms evolved both due to the development of new materials and devices and the increasing appeal and effectiveness of the endovascular therapy itself. Vascular surgeons are using nowadays different solutions of Endovascular Treatment to treat all the expressions of aortic pathology (aneurysms, dissections and trauma) both in the acute and elective setting. Despite its use in every location of the aorta (the ascending aorta, the aortic arch, the thoracic aorta, thoraco-abdominal aorta, pararenal, iuxtarenal and infrarenal aortic aneurysms and iliac aneurysms), its safety and efficiency, endovascular treatment for aortic aneurysms presents some drawbacks: despite a lower short-term morbi-mortality, reinterventions and long-term patency are higher compared to open repair. In this review, we detail the most used types of endografts according to location, their performances and durability for each device. We conclude by discussing options to overcome ET limitations. Therefore, an obvious question arises: what we need in the future? What can the technological progress gives to physicians to further improve this new way of treating aorta?

Remodeling, Reintervention, and Survival After Endovascular Repair of Chronic Type B Dissection

BACKGROUND

The efficacy of thoracic endovascular aortic repair (TEVAR) of chronic type B aortic dissection (cTBAD) is controversial. Only limited evidence describes temporal anatomic changes after TEVAR for cTBAD and their relationship to outcomes. We sought to investigate early aortic remodeling events after TEVAR for cTBAD with thoracic aneurysm and determine the association with reintervention and survival.

METHODS

Records from 95 cTBAD patients undergoing TEVAR from 2005 to 2017 were reviewed. Using 3-dimensional centerline analysis, anatomic phenotyping of the thoracoabdominal aorta was performed. Reverse aortic remodeling (RAR) was defined by a ≥5-mm reduction in maximal thoracic aortic diameter. Kaplan-Meier analysis estimated freedom from reintervention and survival.

RESULTS

Visceral segment dissection involvement was present in 89% of patients (n = 85), and the mean preoperative thoracic diameter was 63 mm (SD, 10). Complete thoracic false lumen thrombosis occurred in 71% of patients (n = 67), whereas abdominal false lumen thrombosis was documented in 60% (n = 57) by 6 months. RAR occurred in 41%. Aortic reintervention rate was 39% (n = 37). The 1- and 3-year freedom from reintervention was significantly higher in subjects experiencing early RAR (log-rank P = .02), but reintervention did not impact overall survival (log-rank P = .9). Similarly, overall survival was similar between patients with or without RAR (log-rank P = .4).

CONCLUSIONS

Early RAR is associated with decreased rates of reintervention; however, overall survival is not impacted by these changes. TEVAR for cTBAD results in a high rate of reintervention, which mandates vigilant surveillance protocols.

One-Year Single-Center Results of the Multilayer Flow Modulator Stents for the Treatment of Type B Aortic Dissection

Purpose

To report a single-center series of patients with type B aortic dissection treated with the Multilayer Flow Modulator (MFM).

Materials and Methods

Over a 36-month period, 23 patients (median age 53 years; 20 men) with complicated type B aortic dissections (2 acute, 5 subacute, and 16 chronic) were treated with the MFM. Primary endpoints of rupture or dissection-related death, overall mortality, and reintervention were evaluated using the Kaplan-Meier method; estimates for freedom from the endpoints are reported with the 95% confidence interval (CI). Secondary outcomes included technical success, adverse events, and aortic remodeling. Clinical and imaging data were collected preoperatively, directly postoperatively, and annually to 36 months for analysis using computational fluid dynamics (CFD).

Results

Initial technical success was 91.3%. The estimates of the endpoints at 12 months were 100% for freedom from rupture or aortic-related death, 95.7% for freedom from overall mortality, and 91.3% for freedom from reintervention. No device-related neurological or systemic complications occurred, and no additional reinterventions were needed during follow-up. A total of 144 branches overstented by the MFM remained patent. Morphologic analysis of the aortic dissection showed progressive true lumen volume increase (75.9%, p<0.001) with concomitant false lumen volume decrease (42.8%, p<0.001); the CFD analyses showed increased laminar flow.

Conclusion

In the current series, the MFM provided a safe and feasible treatment option for complicated acute, subacute, and chronic type B aortic dissections, with high technical success, low mortality, and active aortic remodeling. Further studies should elucidate the long-term safety of the MFM and its effectiveness in a larger patient cohort.

Clinical and Morphologic Outcomes of Endovascular Repair for Subacute and Chronic Type B Aortic Dissection

BACKGROUND

The objective of the study was to assess long-term remodeling, survival, and reintervention outcomes after thoracic endovascular aortic repair (TEVAR) for subacute and chronic type B aortic dissection (TBAD).

METHODS

All patients who underwent TEVAR for subacute or chronic TBAD at a tertiary referral center between 1999 and 2015 were included in this cohort study. The primary outcome was aortic remodeling, and secondary outcomes included survival, rate of major complications, and reinterventions.

RESULTS

Fifty patients were included, with mean age of 62.4 years, 10 (20%) DeBakey type IIIA and 40 (80%) DeBakey type IIIB dissection; 45 standard TEVAR, 2 branched TEVAR, 3 TEVAR combined with fenestrated or branched EVAR. Indication for TEVAR was intact (n = 40) or ruptured (n = 1) postdissection aneurysm, hypoperfusion (n = 4), treatment-refractory pain (n = 2), or a combination (n = 3). Mean clinical follow-up was 76 months, and median radiological follow-up was 46 months. Thirty-day survival was 96%, stroke 4%, renal failure 0%, paraplegia 0%. Three- and five-year survival was 92% (95% confidence interval (CI) [79; 97]) and 77% (95% CI [61; 87]), respectively. Of 19 late deaths, 6 were confirmed aorta related. Five-year freedom from reintervention was 69% (95% CI [53-80]). Distal stent graft extension due to aortic dilatation composed most reinterventions. Mean maximal aortic diameter was 58.7 mm preoperatively and 51.9 mm on last follow-up (P = 0.003). On thoracic level, true lumen expanded (+10.0 mm, 95% CI [6.4; 13.6]) (P < 0.001) and false lumen decreased (-11.9 mm, 95% CI [-15.2; -8.5]) (P < 0.001) from baseline to the last computed tomography. In the abdominal aorta, true lumen diameter change was +3.1 mm (95% CI [1.4; 4.8]) (P = 0.001); false lumen diameter change was +1.0 mm (95% CI [-1.8; 3.8]) (P = 0.464).

CONCLUSIONS

TEVAR for subacute and chronic TBAD results in favorable remodeling of the thoracic but not the abdominal aorta. Five-year survival is almost 80%, but late aortic deaths still occur. Aortic dilatation distal to the treated segment requiring reintervention is common, emphasizing the importance of follow-up.

The surgical management of type IA endoleak after thoracic endovascular aortic repair

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 146.7 ± 42.2 and 81.0 ± 43.3 min, respectively. The selective cerebral perfusion time was 18.8 ± 8.2 min 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 18 months (range 1-84 months). 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.

The role of the axillary Impella 5.0 device on patients with acute cardiogenic shock

Background

Acute cardiogenic shock is associated with high mortality rates. The Impella device is a microaxial left ventricular assist device that can be inserted through the axillary artery. The purpose of our study is to determine the role of the Axillary Impella devices on patients with acute cardiogenic shock.

Methods

A retrospective chart review was conducted to identify patients who underwent Axillary Impella device placement for acute cardiogenic shock from January 1st, 2014 to September 30th, 2018 at a single institution. In-patient records were examined to determine duration of device, length of stay (LOS), postoperative complications, and 30-day in-hospital mortality.

Results

A total of 40 patients, who were primarily men (N = 29) with a mean age of 61.2 ± 10.7 years old, underwent Axillary Impella placement for cardiogenic shock. The primary reasons for implant were (1) required upgraded support from an Impella CP or intra-aortic balloon pump (iabp) to Impella 5.0, (2) to treat left ventricular (LV) distention for patients on extracorporeal mechanical oxygenation (ECMO), and (3) to provide longer term support and allow for mobilization of the patients in whom a device was already indwelling. Twenty-three of the patients had previous devices already in place including a Femoral Impella CP device or an iabp and 9 patients were on ECMO support. The duration of the device was 21.05 ± 17 days with the LOS of 40.8 ± 28 days for those patients. Seventeen of the patients went on to additional surgery including (1) Heartmate 3 device placement (N = 6), (2) other cardiac procedures such as surgical revascularization (N = 9), and orthotopic heart transplantation (N = 2). A total of 21 patients of the 40 (52%) died during their hospitalization with 7 patients (17%) having complications related to the Impella device. These complications included right arm ischemia or neuropathy (N = 3) and Impella malfunction requiring device replacement (N = 4). The majority of these devices were placed in the right axillary artery (N = 38) versus the left axillary artery (N = 2).

Conclusions

A total of 58% (N = 23) of the study patients had previous mechanical support and 23% (N = 9) were on ECMO demonstrating the severity of disease and accounting for the high mortality. The Axillary Impella device allows for a minimally invasively placed device that is durable with a mean duration of 3 weeks. The Axillary artery Impella 5.0 provides upgraded full cardiac support while allowing for mobilization of the patient. In addition, it treats LV distention in patients on ECMO while avoiding sternotomy. Finally, the Axillary Impella provides time for decision making for explant, additional therapy with either long-term devices or orthotopic heart transplant.

A 10-year study of surgical results of descending aorta aneurysm repair following chronic aortic dissection

BACKGROUND

Patients presenting with descending aortic aneurysms developing after aortic dissection often undergo continued aortic expansion which may require operative interventions to address the risk of aortic rupture. In light of the current advances in various treatment options, including endovascular approaches, we analyzed our experience with open surgical repair (OSR) of aneurysms of the descending aorta following aortic dissection.

METHODS

Patients who underwent open repair for aneurysmal changes of the descending aorta after chronic dissection were retrospectively studied. The 30-day operative mortality rate, midterm survival, and major complications were analyzed. Patients were divided into two categories; primary chronic type B aortic dissection and remnant repaired type A aortic dissection (RTAAD).

RESULTS

There were 149 patients with enlargement of the descending thoracic aorta developing after aortic dissection. Of these, 49 patients had medical management, while the remaining 100 patients received OSR. These patients were included in the present analysis. The 30-day mortality and permanent paraplegia rates were 9% and 4%, respectively. The 1-, 3-, and 5-year survival rates were 83%, 80.9%, and 76.1%, respectively. The 1- and 5-year survival rates between the primary chronic type B aortic dissection and remnant RTAAD groups showed no significant between-group differences at 86.7% and 84.3%, and 80% and 71.3%, respectively (P = .289). The overall outcomes of other complications such as renal injury, bleeding reoperation, and extracorporeal membrane oxygenation support showed no significant between-group differences, including an insignificantly higher neurologic complication rate in the remnant RTAAD group. The survival rate in patients with Marfan syndrome was significantly higher than in the patients without Marfan syndrome (P = .033).

CONCLUSIONS

OSR for descending aortic aneurysms developing after chronic aortic dissection showed good early and mid- to long-term outcomes, with acceptably low complication rates. OSR for descending aortic aneurysm after chronic aortic dissection associated with Marfan syndrome also showed good early and mid- to long-term outcomes.

Role of Endoluminal Techniques in the Management of Chronic Type B Aortic Dissection

In recent guidelines of international societies, the most frequent indication for treatment after chronic type B aortic dissection (cTBAD) is aneurysmal dilatation. Endovascular repair is recommended in patients with moderate to high surgical risk or with contraindications to open repair. During the last decade, many advances have been made in the field of endovascular techniques and devices. The aim of this article is to address the current status of endoluminal techniques for the management of cTBAD including standard thoracic endovascular repair, new devices, fenestrated and branched abdominal aortic devices and false lumen occlusion techniques.

Fenestrated/Branched Endovascular Repair for Postdissection Thoracoabdominal Aneurysms: A Systematic Review with Pooled Data Analysis

PURPOSE

Patients who have survived an acute aortic dissection remain at risk for postdissection thoracoabdominal aortic aneurysms (PD-TAAAs). Fenestrated/branched endovascular repair for PD-TAAA is increasingly used in some high-volume centers, but outcomes are still limited because of the additional challenges compared to atherosclerotic thoracoabdominal aneurysms. This study was performed to evaluate the literature on fenestrated/branched endovascular repair for PD-TAAAs.

METHODS

PubMed, Embase, and the Cochrane Database were searched for relevant studies published until September 2019. Outcome data were extracted to evaluate the technical success, 30-day mortality, later survival, major complications, endoleaks, target vessel patency, and reintervention. Studies were analyzed in a pooled proportion meta-analysis.

RESULTS

In total, 143 patients from 4 studies were identified for the pooled data analysis. The pooled technical success rate was 98% (95% CI: 86%-100%). After the treatment, the overall estimated 30-day mortality rate was 3% (95% CI: 1%-8%), early spinal cord ischemia rate was 10% (95% CI: 4%-21%), early renal injury rate was 5% (95% CI: 1%-19%), endoleak rate was 33% (95% CI: 22%-47%), reintervention rate at a median follow-up of 22.5 months was 34% (95% CI: 27%-42%), and all-cause mortality rate was 12% (95% CI: 6%-24%).

CONCLUSIONS

The use of fenestrated/branched stent grafts for the treatment of PD-TAAA appears generally feasible based on the limited literature, but endoleaks and reinterventions are frequent.