Dissection length-to-descending thoraco-abdominal aorta length ratio predicts abdominal aortic enlargement after thoracic endovascular aortic repair for type B aortic dissection involving the abdominal aorta

OBJECTIVES

This study was performed to assess the association between the dissection length-to-descending thoraco-abdominal aorta length ratio (LLR) and abdominal aortic enlargement (AAE) (≥20% increase in total abdominal aortic volume) after thoracic endovascular aortic repair (TEVAR) in patients with type B aortic dissection.

METHODS

We retrospectively analysed data from 184 consecutive patients with type B aortic dissection who underwent TEVAR from January 2011 to December 2016 at 4 hospitals as part of the Registry Of type B aortic dissection with Utility of STent graft study. Preoperative and postoperative computed tomography angiography images were reviewed to assess the LLR and AAE. Patients were stratified into tertiles according to the pre-TEVAR LLR: 0.7 to <1.0 (n = 61), 1.0 to <1.2 (n = 61) and 1.2 to <1.6 (n = 62). The thoracic and abdominal aorta were divided by the celiac trunk. The cumulative incidence of AAE was estimated using the Kaplan-Meier method. A multivariable Cox proportional hazards model was used to assess the independent association between the preoperative LLR and the post-TEVAR risk of AAE. The nonlinear relationship between the LLR and the risk of post-TEVAR AAE was fitted by the restricted cubic smoothing spline, and the inflection point on the fitting curve was determined using a piecewise linear regression model.

RESULTS

Baseline demographics, clinical features, preoperative anatomic characteristics and implanted devices were similarly distributed among the pre-TEVAR LLR tertile groups. At 24 months post-TEVAR, the estimated cumulative incidence of AAE significantly differed (P < 0.01) by LLR tertile group: 0.10 [95% confidence interval (CI) 0.00-0.21], 0.65 (95% CI 0.45-0.78) and 0.67 (95% CI 0.40-0.82), respectively. The pre-TEVAR LLR was an independent predictor of post-TEVAR AAE [hazard ratio (per unit increase) 1.03, 95% CI 1.01-1.04] following a nonlinear relationship with an inflection point at LLR = 1.0.

CONCLUSIONS

The risk of post-TEVAR AAE is highest when the length of the dissection is greater than or equal to the length of the descending aorta (LLR ≥ 1.0).

Association between aortic arch angulation and bird-beak configuration after thoracic aortic stent graft repair of type B aortic dissection

OBJECTIVES

The goal of this study was to investigate factors favouring the bird-beak configuration after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection.

METHODS

We retrospectively analysed 76 patients with type B aortic dissection who underwent landing zone 1 and 2 TEVAR from December 2015 to January 2018. Preoperative aortic arch geometry (aortic arch length, maximal diameter and angulation), stent graft details and operative details were evaluated. A bird-beak configuration was defined as a ≥5-mm gap between the proximal end of the stent and the aortic wall of the lesser curvature.

RESULTS

Patients were stratified into those with (n = 46) and without (n = 30) a bird-beak configuration. The baseline demographics, dissection chronicity, clinical features and implanted devices were largely similar between the 2 groups. No significant difference was observed in the arch length or maximal arch diameter. However, the mean aortic arch angulation was greater in patients with than without a bird-beak configuration (61.4° vs 51.3°; P < 0.001). No influence of either the stent graft brand or the proximal stent graft type was observed. The multivariable analysis showed that the aortic arch angulation was an independent risk factor for a bird-beak configuration (odds ratio 1.15, 95% confidence interval 1.07-1.24; P < 0.001). A cut-off angle of 59.15° was predictive of a bird-beak configuration (sensitivity 59%; specificity 77%).

CONCLUSIONS

The preoperative aortic arch angulation was an independent predictor of a postoperative bird-beak configuration in patients with type B aortic dissection who underwent TEVAR that involved the aortic arch. An angle of >59.15° may imply a relatively hostile anatomy with a higher risk of a bird-beak configuration.

Endovascular aortic arch repair with a pre-cannulated double-fenestrated physician-modified stent graft: a benchtop experiment

OBJECTIVES

The critical step in total endovascular aortic arch repair is to ensure alignment of fenestrations with, and thus maintenance of flow to, supra-aortic trunks. This experimental study evaluates the feasibility and accuracy of a double-fenestrated physician-modified endovascular graft [single common large fenestration for the brachiocephalic trunk and left common carotid artery and a distal small fenestration for left subclavian artery (LSA) with a preloaded guidewire for the LSA] for total endovascular aortic arch repair.

METHODS

Eight fresh human cadaveric thoracic aortas were harvested. Thoracic endografts with a physician-modified double fenestration were deployed for total endovascular aortic arch repair in a bench test model. A guidewire was preloaded through the distal fenestration for the LSA. All experiments were undertaken in a hybrid room under fluoroscopic guidance with subsequent angioscopy and open evaluation for assessment.

RESULTS

Mean aortic diameter in zone 0 was 31.3 ± 3.33 mm. Mean duration for stent graft modification was 20.1 ± 5.8 min. Mean duration of the procedure was 24 ± 8.6 min. The Medtronic Valiant Captivia stent graft was used in 6 and the Cook Alpha Zenith thoracic stent graft in 2 cases. LSA catheterization was technically successful with supra-aortic trunk patency in 100% of cases.

CONCLUSIONS

The use of a double-fenestrated stent graft with a preloaded guidewire appears to be a useful technical addition to facilitate easy and correct alignment of stent graft fenestrations with supra-aortic trunk origins.

Results of endovascular aortic arch repair using the Relay Branch system

OBJECTIVES

Our goal was to evaluate results of endovascular aortic arch repair using the Relay Branch system.

METHODS

Forty-three patients with thoracic aortic pathology involving the aortic arch have been treated with the Relay Branch system (Terumo Aortic, Sunrise, FL, USA) in 10 centres. We assessed in-hospital mortality, neurological injury, treatment success according to current reporting standards and the need for secondary interventions. In addition, outcome was analysed according to the underlying pathology: non-dissective disease versus residual aortic dissection (RAD) (defined as remaining dissection after previous type A repair, chronic type B aortic dissections).

RESULTS

In-hospital mortality was 9% (0% in patients with RAD). Disabling stroke occurred in 7% (0% in patients with RAD); non-disabling stroke occurred in 19% (7% in patients with RAD). Early type IA and B endoleak formation occurred in 4%. Median follow-up was 16 ± 18 months. During the follow-up period, 23% of the patients died. Aortic-related deaths were low (3% in patients with RAD).

CONCLUSIONS

The results of endovascular aortic arch repair using the Relay Branch system in a selected patient population with regard to technical success are good. In-hospital mortality is acceptable, the number of disabling strokes is low and technical success is high. Non-disabling stroke is a major concern, and every effort has to be taken to reduce this to a minimum. The best outcome is seen in patients with underlying RAD. Finally, more data are needed.

Thoracic endovascular aortic repair for recurrent stroke due to atheromatic plaque in the proximal descending aorta: a case report

Background

Diastolic retrograde flow in the descending aorta (DAo) may occur in the presence of atherosclerosis and may be overlooked as a mechanism of retrograde embolization in patients with stroke. We performed thoracic endovascular aortic repair (TEVAR) in a patient with recurrent cerebral infarctions for treatment of aortic aneurysm with atheromatic plaque, which was considered as the source of embolism.

Case presentation

A 56-year-old man with a history of idiopathic thrombocytopenia and hypertension was referred to our hospital with paralysis of the right upper and lower limbs. Multiple cerebral infarctions were found and treated; however, 1 month later, another cerebral infarction developed. A small saccular aortic aneurysm with plaque was found beyond the left subclavian artery, and this site was deemed as the source of embolism. We performed TEVAR to prevent further recurrence of cerebral infarctions. No cerebral infarctions were observed 6 months post-operation.

Conclusions

TEVAR is a useful treatment for not only aortic aneurysm and dissection, but also cerebral infarctions caused by an embolic source proximal to the DAo due to retrograde aortic blood flow.

Unique characteristics of the type B aortic dissection patients with malperfusion in the Vascular Quality Initiative

OBJECTIVE

Type B aortic dissection (TBAD) complicated by malperfusion carries high morbidity and mortality. The present study was undertaken to compare the characteristics of malperfusion and uncomplicated cohorts and to evaluate the long-term differences in survival using a granular, national registry.

METHODS

Patients with TBAD entered into the thoracic endovascular aortic repair/complex endovascular aortic repair module of the Vascular Quality Initiative from 2010 to 2019 were included. The demographic, radiographic, operative, postoperative, in-hospital, and long-term reintervention data were compared between the malperfusion and uncomplicated TBAD groups using t tests and χ² analysis, as appropriate. Overall survival was compared using Cox regression to generate survival curves.

RESULTS

Of the 2820 included patients, 2267 had uncomplicated TBAD and 553 had malperfusion. The patients with malperfusion were younger (age, 55.8 vs 61.2 years; P < .001), were more often male (79.7% vs 68.1%; P < .001), had a higher preoperative creatinine (1.8 vs 1.1 mg/dL; P < .001), had more often presented with an American Society of Anesthesiologists class of 4 or 5 (81.9% vs 58.4%; P < .001), and had more often presented with urgent status (77.4% vs 32.8%; P < .001). In contrast, the uncomplicated TBAD group had had more medical comorbidities, including coronary artery disease and chronic obstructive pulmonary disease, and a larger aortic diameter (4.0 cm vs 4.9 cm; P < .001). The malperfusion group more frequently had proximal zones of disease in zones 0 to 2 (38.6% vs 31.5%; P = .002) and distal zones of disease in zones 9 and above (78.7% vs 46.2%; P < .001), with a greater number of aortic zones traversed (7.7 vs 5.1; P < .001) and a greater frequency of dissection extension into branch vessels (61.8% vs 23.1%; P < .001). Patients with malperfusion also exhibited greater case complexity, with a greater need for branch vessel stenting and longer procedure times. The overall incidence of postoperative complications was greater in the malperfusion group (39.4% vs 17.1%; P < .001) and included a greater rate of spinal cord ischemia (6.3% vs 2.2%; P < .001), acute kidney injury (10.4% vs 0.9%; P < .001), and in-hospital mortality (11.6% vs 5.6%; P < .001). In-hospital reintervention was also greater for the malperfusion patients (14.5% vs 7.4%; P < .001), although the incidence of long-term reinterventions was similar between the two groups (8.7% vs 9.7%; P = .548). A proximal zone of disease in zone 0 to 2 was associated with decreased survival. In contrast, a distal zone of disease in 9 and above, in-hospital reintervention, and long-term follow-up were associated with increased survival. Despite these differences, long-term survival did not differ between the malperfusion and uncomplicated groups (P = .320.) CONCLUSIONS: Patients presenting with TBAD and malperfusion represent a unique cohort. Despite the greater need for branch vessel stenting and in-hospital reintervention, they had similar long-term reintervention rates and survival compared with those with uncomplicated TBAD. These data lend insight with regard to the observed differences between uncomplicated and malperfusion TBAD.

A preliminary analysis of late structural failures of the Navion stent graft in the treatment of descending thoracic aortic aneurysms

OBJECTIVE

Patients in the Valiant Evo U.S. and international clinical trials had positive short-term outcomes; however, late structural failures, including type IIIb endoleaks have been recently discovered. Type IIIb endoleaks are serious adverse events because the repressurization of the aneurysm sac increases the risk of rupture. The purpose of the present study was to detail the imaging patterns associated with the structural failures with the aim of increasing awareness of failing graft presentation, early recognition, and prompt treatment.

METHODS

The Valiant Evo clinical trial was a prospective, single-arm investigation of a thoracic stent graft system. With the recent late structural failures, sites were requested to submit all available imaging studies to date to allow the core laboratory to assess for structural failures such as type IIIb endoleaks, stent ring fractures, and stent ring enlargement. Of the 100 patients originally enrolled in the trial from 2016 to 2018, the core laboratory assessed the imaging studies performed at ≥1 year for 83 patients.

RESULTS

No structural failures of the graft were reported through 1 year of follow-up. At 1 to 4 years, graft structural failures were detected in 11 patients with descending thoracic aortic aneurysms. Of the 11 patients, 5 had a type IIIb endoleak. Four of the five had imaging findings showing stent fractures consistent with the location of the graft seam and one had a type IIIb endoleak attributed to calcium erosion with no stent fracture or ring enlargement. Of the four patients with stent fracture in line with the graft seam, three underwent a relining procedure that successfully excluded the type IIIb endoleak. One of these three patients died 4 days later of suspected thoracic aortic rupture because the distal thoracic endovascular aortic repair extension had been landed in a previously dissected and fragile section of the aorta. The remaining six patients had had stent ring enlargement. One of the six patients had had persistent aneurysm expansion from the time of implantation onward and had died of unknown causes. The remaining five patients have continued to be monitored.

CONCLUSIONS

In the present preliminary analysis, the imaging patterns associated with type IIIb endoleaks, stent fractures, and stent ring enlargement appear to be related to the loss of seam integrity or detachment of the stent rings from the surface of the graft material. The imaging patterns we have detailed should be closely monitored using computed tomography angiography surveillance to allow structural failures to be promptly identified and treated.

Prediction of Distal Aortic Enlargement after Proximal Repair of Aortic Dissection Using Machine Learning

OBJECTIVES

This study aimed to construct a risk prediction model for distal aortic enlargement in patients with type B aortic dissection (TBAD) treated with proximal thoracic endovascular aortic repair (TEVAR).

METHODS

From June 2010 to June 2016, patients with TBAD who underwent proximal TEVAR were retrospectively analyzed. A total of 38 clinical and imaging variables were collected. Univariable logistic regression was conducted to explore potential risk factors associated with distal aortic enlargement. Elastic net regression was employed to select significantly influential variables. Then, machine learning algorithms (logistic regression (LR), artificial neutral network (ANN), random forest and support vector machine) were applied to build risk prediction models. The area under the receiver operating characteristic curve (AUC), sensitivity and specificity were used to evaluate the performance of these models.

RESULTS

A total of 503 patients were enrolled in this study. During the follow-up, 105 (20.9%) patients were identified as having distal aortic enlargement, and 69 (13.7%) patients were found to have distal aortic aneurysm formation. Five patients were identified with aortic rupture. True lumen collapse and multi-false lumens were two potential risk factors for distal aortic enlargement after proximal repair of TBAD. The LR model performed the best in predicting distal aortic enlargement, with the highest sensitivity (96.7%) and an AUC of 0.773. The best model for predicting distal aneurysm formation was the ANN model, which yielded the highest AUC (0.876) and a specificity of 79.1%.

CONCLUSIONS

Machine learning approaches can produce accurate predictions of distal aortic enlargement after proximal repair of TBAD, which potentially benefits subsequent management.

Native and prosthetic graft infections of the thoracic aorta: surgical management

 

OBJECTIVES

Infection of the native aorta or after previous open or endovascular repair of the thoracic aorta is associated with high risks for morbidity and mortality. We analysed the outcome after surgical management of a native mycotic aneurysm or of prosthetic graft infection of the descending aorta.

METHODS

From June 2000 to May 2019, a total of 39 patients underwent surgery in our centre for infection of the native descending aorta (n = 19 [49%], group A) or a prosthetic descending aorta [n = 20 (51%), group B]. In the 20 patients in group B, a total of 8 patients had prior open aortic repair with a prosthesis and 12 patients had a previous endovascular graft repair.

RESULTS

The cohort patients had a mean age of 57 ± 14; 62% were men (n = 24). The most common symptoms at the time of presentation included fever, thoracic or abdominal pain and active bleeding. Emergency surgery was performed in 11 patients (28%); 3 patients had emergency endovascular stent grafts implanted during thoracic endovascular aortic repair for aortic rupture before further open repair. The 30-day mortality was 42% in group A and 35% in group B. The 90-day mortality was 47% in group A and 45% in group B. Pathogens could be identified in approximately half of the patients (46%). The most commonly identified pathogens were Staphylococcus aureus in 6 patients (15%) and Staphylococcus epidermidis in 4 patients (10%). Survival of the entire group (including patients with both native and prosthetic graft infections) was 44 ± 8%, 39 ± 8% and 39 ± 8% at 1, 2 and 3 years after surgery. The percentage of patients who survived the initial perioperative period was 81 ± 9%, 71 ± 9% and 71 ± 10% at 1, 2 and 3 years after surgery.

CONCLUSIONS

Patients with infection of the descending aorta, either native or prosthetic, are associated with both high morbidity and mortality. However, patients who survive the initial perioperative period have an acceptable long-term prognosis. In emergency situations, thoracic endovascular aortic repair may help to stabilize patients and serve as bridge to open repair.

Prognostic dynamic nomogram integrated with metabolic acidosis for in-hospital mortality and organ malperfusion in acute type B aortic dissection patients undergoing thoracic endovascular aortic repair

BACKGROUND

Organ malperfusion is a lethal complication in acute type B aortic dissection (ATBAD). The aim of present study is to develop a nomogram integrated with metabolic acidosis to predict in-hospital mortality and organ malperfusion in patients with ATBAD undergoing thoracic endovascular aortic repair (TEVAR).

METHODS

The nomogram was derived from a retrospectively study of 286 ATBAD patients who underwent TEVAR from 2010 to 2017 at a single medical center. Model performance was evaluated from discrimination and calibration capacities, as well as clinical effectiveness. The results were validated using a prospective study on 77 patients from 2018 to 2019 at the same center.

RESULTS

In the multivariate analysis of the derivation cohort, the independent predictors of in-hospital mortality and organ malperfusion identified were base excess, maximum aortic diameter ≥ 5.5 cm, renal dysfunction, D-dimer level ≥ 5.44 μg/mL and albumin amount ≤ 30 g/L. The penalized model was internally validated by bootstrapping and showed excellent discriminatory (bias-corrected c-statistic, 0.85) and calibration capacities (Hosmer-Lemeshow P value, 0.471; Brier Score, 0.072; Calibration intercept, - 0.02; Slope, 0.98). After being applied to the external validation cohort, the model yielded a c-statistic of 0.86 and Brier Score of 0.097. The model had high negative predictive values (0.93-0.94) and moderate positive predictive values (0.60-0.71) for in-hospital mortality and organ malperfusion in both cohorts.

CONCLUSIONS

A predictive nomogram combined with base excess has been established that can be used to identify high risk ATBAD patients of developing in-hospital mortality or organ malperfusion when undergoing TEVAR.

The 3-step approach for the treatment of multisegmental thoraco-abdominal aortic pathologies

OBJECTIVES

The goal of this study was to describe our 3-step approach to treat multisegmental thoraco-abdominal aortic disease due to aortic dissection and to present our initial clinical results.

METHODS

Nine patients with multisegmental thoraco-abdominal aortic pathology due to aortic dissection underwent our 3-step approach, which consisted of total aortic arch replacement via the frozen elephant trunk technique, thoracic endovascular aortic repair for distal extension down to the level of the thoraco-abdominal transition and, finally, open thoraco-abdominal aortic replacement for the remaining downstream aortic segments. We assessed their baseline and aortic characteristics, previous aortic procedures, intraoperative details, clinical outcomes and follow-up data.

RESULTS

The median age was 58 (42-66) years; 4 patients (44%) presented connective tissue disease. Eight patients (89%) had undergone previous aortic surgery for aortic dissection. In-hospital mortality was 0% (n = 0). None suffered symptomatic spinal cord injury or disabling stroke. During the follow-up period, 1 patient died of acute biliary septic shock 6 months after thoraco-abdominal aortic replacement.

CONCLUSIONS

The 3-step approach to treat multisegmental thoraco-abdominal aortic pathology due to aortic dissection, which involves applying both open and endovascular techniques, is associated with an excellent clinical outcome and low perioperative risk. Distal shifting of the disease process through the thoracic endovascular aortic repair extension-and thereby necessitating limited open thoraco-abdominal aortic repair-seems to be the major factor enabling these favourable results.

IRB APPROVAL

IRB approval was obtained (No. 425/15) from the institutional review board of the University of Freiburg.

Elevated preoperative neutrophil-to-lymphocyte ratio predicts early adverse outcomes in uncomplicated type B aortic dissection undergoing TEVAR

BACKGROUND

Thoracic aortic endovascular repair (TEVAR) of uncomplicated type B aortic dissection (uTBAD) has favorable long-term outcomes but higher early adverse events compared with the optimal medical treatment. Recently, clinical evidence concerning vascular surgery indicates that elevated preoperative systemic inflammatory response predicts adverse clinical events. The aim of our study was to evaluate the relationship between preoperative neutrophil-to-lymphocyte ratio (NLR) and early outcomes of uTBAD patients undergoing TEVAR.

RESULTS

216 patients diagnosed with uTBAD were included in this retrospective study between January 2015 and December 2018. The median (IQR) follow-up period was 21 (15-33) months. An early adverse event was defined as occurring within 2 years after the procedure. Median patient age was 60 (IQR, 48-68) years and 78.7 % were male. Early adverse events occurred in 24 patients (11.1 %). In the multivariable analysis, preoperative NLR (HR per SD, 1.98; 95 % CI, 1.14-3.44; P = 0.015) was associated with 2-year adverse events.

CONCLUSIONS

NLR is an independent predictive factor of early adverse events in uTBAD patients undergoing TEVAR.

Meta-analysis of outcomes after intentional coverage of celiac artery in thoracic endovascular aortic repair

OBJECTIVE

The aim of the present study was to demonstrate the clinical outcomes of intentional coverage of the celiac artery (CA) during thoracic endovascular aneurysm repair (TEVAR).

METHODS

The MEDLINE, EMBASE, and Cochrane Library databases were searched for studies reporting coverage of CA during TEVAR. The methodologic quality of the included studies was assessed using the Moga score and Newcastle-Ottawa scale. A random effects model was used to pool the estimates. A meta-analysis was performed with investigation of the following outcomes: visceral ischemia, spinal cord ischemia (SCI), stroke, endoleak, reintervention, 30-day mortality, and 1-year mortality.

RESULTS

A total of 10 studies with 171 patients were included. The summary estimate rate of visceral ischemia events was 4.2% (95% confidence interval [CI], 0.9-8.9%; I² = 4.1%). The incidence of stroke and SCI was 0.2% (95% CI, 0%-3.4%; I² = 0%) and 3% (95% CI, 0.3%-7.4%; I² = 6.1%). The rate of endoleak during the follow-up period was 24.1% (95% CI, 14.3%-35.1%; I² = 20.0%). The reintervention rate was 13.6% (95% CI, 4.4%-25.7%; I² = 66.0%). The 30-day and 1-year mortality were 2.9% (95% CI, 0.3%-7.2%; I² = 6.2%) and 15.2% (95% CI, 7.8%-23.9%; I² = 0%).

CONCLUSIONS

Among the patients with complex thoracic aortic pathologies deemed at high risk for open reconstruction, TEVAR with intentional coverage of the CA is a safe and feasible option to extend the distal sealing zone with acceptable rates of visceral ischemia, SCI, type II endoleak from the CA, and 30-day mortality.

Clinical trial outcomes and thoracic aortic morphometry after one year with the Valiant Navion stent graft system

AUTHORS' NOTE

On February 17, 2021, Medtronic Incorporated issued a global voluntary recall of the Valiant Navion Thoracic Stent Graft System (the device under study in the Valiant Evo Global Clinical Program that is the subject of this publication), and instructed physicians to immediately cease use of the Valiant Navion system and return any unused product. Medtronic initiated the recall in response to three clinical trial subjects recently observed with stent fractures, two of whom have confirmed type IIIb endoleaks. The data collection, analysis, and manuscript submission occurred before the notice of this recall, and, specifically, the 100 procedures reviewed for this series were free of events at 1 year related to the reason for this device recall. The authors of this article and the manufacturer were unaware of the recently detected adverse events at the time of the preparation of the manuscript, and the 1-year trial results, and imaging-based analyses described are unchanged. Management of thoracic aortic aneurysms continues to be a challenging problem and outcomes are dependent on patient anatomy. The present publication focuses on the importance of achieving proximal and distal seals and the consideration of the temporal changes of the aortic morphology as a part of the TEVAR planning process. The authors believe there is still scientific merit in disclosing this information, despite the current nonavailability of the Valiant Navion system.

OBJECTIVE

The Valiant Navion stent graft system (Medtronic Inc, Santa Rosa, Calif) is a third-generation device with improved conformability. We have reported the 1-year clinical trial outcomes, with a focus on an imaging-based analysis of the aortic morphology. We assessed the effects of graft implantation on the native anatomy and the effects of the 1-year changes in thoracic aorta morphology on the original seal zones of the stent graft.

METHODS

A total of 100 subjects were enrolled in a prospective single-arm clinical trial investigating the Valiant Navion stent graft system. An independent core laboratory (Syntactx, New York, NY) assessed the anatomic characteristics and performance outcomes.

RESULTS

Through 1 year of follow-up, the freedom from all-cause mortality, aneurysm-related mortality, and secondary procedures was 89.8%, 97.0%, and 94.8% respectively. Of the 100 patients, 5 had undergone a total of six secondary procedures, and 9 patients had developed an endoleak (type Ia and Ib in 1, type Ia in 1, type Ib in 3, and type II in 4 patients) within the first year. After 1 year, 2 of 76 patients (2.6%) had had an increase in their maximum aneurysm diameter of ≥5 mm, 62 (81.6%) had had stable sacs, and 12 (15.8%) had experienced sac shrinkage. Although no deployment failures had occurred, 36 of the 100 proximal (36%) and 31 of the 100 distal (31%) attachment zones were considered short according to our definitions. The stent graft had conformed to the native anatomy at implantation, because the preprocedural thoracic aorta tortuosity (1.45 ± 0.02) had not significantly changed at 1 month after implantation (1.46 ± 0.02). Despite a natural increase in thoracic tortuosity after 1 year (1.49 ± 0.02), wall apposition had been maintained over time, as evidenced by the low endoleak rates. Aortic elongation and dilation had occurred at the proximal end of the graft by an average of 1.2 mm and 1.6 mm, respectively. Aortic remodeling was more pronounced at the distal end, with an average increase of 4.2 mm in length and 2.8 mm in diameter.

CONCLUSIONS

The included patients had had positive 1-year outcomes with high freedom from mortality, endoleak development, and secondary procedures. Aortic elongation and dilation were more prevalent at the distal end, emphasizing the importance of distal attachment zone consideration as part of preoperative planning. Because aortic remodeling can be expected to continue over time, additional follow-up and imaging analysis in the trial will be necessary to assess the aortic morphology and its effects on stent graft performance.

Severe intraluminal atheroma and iliac artery access affect spinal cord ischemia after thoracic endovascular aortic repair for degenerative descending aortic aneurysm

OBJECTIVES

This study aimed to reveal additional factors potentially contributing to the multifactorial ethiopathogenesis of spinal cord ischemia (SCI) after thoracic endovascular aortic repair (TEVAR) for descending thoracic aortic aneurysm (TAA).

METHODS

The medical records of 293 patients who underwent TEVAR without debranching procedures for descending TAA between 2011 and 2018 were retrospectively reviewed. We excluded the following cases from the study: 72 patients with aortic dissection; 15 with rupture; 14 with anastomotic pseudoaneurysm; 22 with re-TEVAR; 34 without evaluation of the artery of Adamkiewicz (AKA). Sufficient data were available for 136 patients (79% men; mean age of 76 ± 7.4 years). We conducted univariable and multivariable analyzes using the logistic regression analysis to assess the relationship between pre-/intraoperative factors and postoperative SCI.

RESULTS

SCI was observed in nine patients (6.8%). Severe intraluminal atheroma [odds ratio (OR), 6.23; p = 0.014] and iliac artery access (OR 4.65; p = 0.043) were identified as the positive predictors of SCI by univariable analysis. Risk factors of SCI were determined additionally as follows: coverage of the intercostal artery branching AKA (ICA-AKA) (OR 4.89; p = 0.054); coverage of the ICA-AKA combined with iliac access (OR 10.1; p = 0.002); that combined with severe intraluminal atheroma (OR 13.7; p = 0.001).

CONCLUSION

Severe intraluminal atheroma and iliac artery access were the independent predicting factors of SCI after TEVAR for degenerative descending TAA. In patients with complicated aortoiliofemoral access route, coverage of the ICA-AKA is associated with the risk of SCI.

3D Morphologic Findings Before and After Thoracic Endovascular Aortic Repair for Type B Aortic Dissection

BACKGROUND

Stanford type-B aortic dissection (TBAD) is commonly treated by thoracic endovascular aortic repair (TEVAR). Usually, the implanted stent-grafts will not cover the entire dissection-affected region for those patients with dissection extending beyond the thoracic aorta, thus the fate of the uncovered aortic segment is uncertain. This study used 3-dimensional measurement of aortic morphological changes to classify the different remodeling effects of TBAD patients after TEVAR, and hypothesized that not only initial morphological features, but also their change over time at follow-up are associated with the remodeling.

METHODS

Forty-one TBAD patients underwent TEVAR and CT-angiography before and after the intervention (twice or more follow-ups) were included in this study. According to the false-lumen volume variations post-TEVAR, patients who had abdominal aortic expansion at the second follow-up were classified into the Enlarged (n =12, 29%) and remaining into the Stable group (n = 29, 71%). 3D morphological parameters were extracted on precise reconstruction of imaging datasets. Statistical differences in 3D morphological parameters over time between the 2 groups and the relationship among these parameters were analyzed.

RESULTS

In the Enlarged group, the number of all tears before TEVAR was significantly higher (P = 0.022), and the size of all tears at the first and second follow-up post-TEVAR were significantly higher than that in the Stable group (P = 0.008 and P = 0.007). The location of the primary tear was significantly higher (P = 0.031) in the Stable group. The cross-sectional analysis of several slices below the primary tear before TEVAR shows different shape features of the false lumen in the Stable (cone-like) and Enlarged (hourglass-like) groups. The number of tears before TEVAR has a positive correlation with the post-TEVAR development of dissection (r = 0.683, P = 0.00).

CONCLUSION

The results in this study indicated that the TBAD patients with larger tear areas, more re-entry tears and with the primary tear proximal to the arch would face a higher risk of negative remodeling after TEVAR.

Clinical Outcomes of Distal Tapered Restrictive Covered Stent Applied in Endovascular Treatment of Aortic Dissection Involving Zone 0

OBJECTIVE

The safety and efficacy of a distal tapered restrictive covered stent (RCS) applied in the endovascular treatment of aortic dissection involving Zone 0 was evaluated.

METHODS

This study retrospectively analysed 43 patients with acute aortic dissection involving Zone 0 who received in situ laser fenestrated thoracic endovascular aortic repair with distal tapered RCS from January 2015 to February 2019. The indication for the distal tapered RCS procedure was an inappropriate distal size of the main stent graft. Technical success, aortic remodelling, and clinical outcomes were evaluated.

RESULTS

Technical success was achieved in all patients. The 30 day post-operative mortality rate was 0%. All patients had complete false lumen thrombosis in the stent coverage segment. True lumen volume increased significantly (p < .001) with an average change of 87.0% ± 34.3%, while false lumen volume decreased significantly (p < .001) with an average change of -71.0% ± 13.5% between baseline and 12 months. During the follow up period (mean 28.7 months, range 12-63 months), no distal stent graft induced new entry (SINE) was observed. The average distance between the distal end of the RCS and the coeliac trunk was 57.5 mm. Two (4.7%) patients had spinal cord ischaemia (SCI) and recovered without permanent paraplegia after undergoing conservative treatment.

CONCLUSION

The distal tapered RCS applied in the endovascular treatment of aortic dissection involving Zone 0 is considered to be a feasible and effective approach along with satisfactory aortic remodelling, a low risk of SINE, and SCI. The favourable results are partly explained by selection. No patients had an entry tear near the coronary artery, nor were the coronary arteries, pericardium, or aortic valve involved at the time of repair.

Evaluation of Zone 2 Thoracic Endovascular Aortic Repair Performed with and without Prophylactic Embolization of the Left Subclavian Artery in Patients with Traumatic Aortic Injury

OBJECTIVE

To report the authors' experience in performing thoracic endovascular aortic repair (TEVAR) for zone 2 lesions after traumatic aortic injury (TAI).

MATERIALS AND METHODS

This retrospective review included 10 patients who underwent zone 2 TEVAR after identification of aortic isthmus injury by CT angiography (CTA) upon arrival at the emergency room of a regional trauma center from 2016 to 2019. Patients were classified into two groups: those who underwent left subclavian artery (LSA) embolization concurrently with the main TEVAR procedure, and those in whom LSA embolization was not performed during the main procedure, but was planned as a bailout treatment if type II endoleak was noted on follow-up CTA images. Pre-procedural and procedure-related factors and post-procedure prognosis were compared between the groups.

RESULTS

There were no differences in pre-procedural factors, occurrence of endoleaks, and post-procedure prognosis (including mortality) between patients in the two groups. The duration of the procedure was shorter in the non-LSA embolization group (61 minutes vs. 27 minutes, p = 0.012). During follow-up, type II endoleak did not occur in either group.

CONCLUSION

Delaying preventative LSA embolization until stabilization of the patient would be desirable when performing zone 2 TEVAR for TAI, in the absence of endoleak on the completion aortography image taken after complete deployment of the stent graft.

[The Characteristics of Aortic Remodeling after Thoracic Endovascular Aortic Repair using Two-stent Graft Implantation for Stanford Type B Aortic Dissection]

OBJECTIVE

To investigate the characteristics of aortic remodeling after thoracic endovascular aortic repair using two-stent graft implantation (TEVAR-TSI) for Stanford B aortic dissection.

METHODS

The clinical and imaging data of 128 patients who underwent TEVAR-TSI for Stanford B aortic dissection in the First Affiliated Hospital of Hebei North University from January 2013 through May 2019 were retrospectively collected. CT images were obtained before (T 0) TEVAR-TSI and, 1 week (T 1), 3 months (T 2), 6 months (T 3), 1 year (T 4) after TEVAR-TSI. The maximum diameter of the true lumen and false lumen in the short axis view was accessed at five levels: L 1: the level of primary tear entry, L 2: the level of the bronchial bifurcation, L 3: the level of the distal of the first stent-graft, L 4: the level of the celiac trunk, L 5: the level of the lowest renal arteries. The false lumen thrombosis in the thoracic aorta and abdominal aorta were assessed at different times, the false lumen and true lumen changes in diameter were evaluated between the preoperative and postoperative CT scan.

RESULTS

The stented segment of the descending thoracic aorta was evaluated (L 1-L 3): The true lumen diameter showed an increasing trend and the false lumen diameter showed an decreasing trend at levels L 1, L 2, and L 3, the change of true lumen diameter was positively correlated with the follow-up time ( r=0.721, 0.827, 0.893, P<0.05), and the change rate of true lumen diameter was positively correlated with the follow-up time ( r=0.763, 0.818, 0.902, P<0.05), and the change of false lumen diameter was negatively correlated with the follow-up time ( r=-0.750, -0.927, -0.934, P<0.05), and the change rate of false lumen diameter was negatively correlated with the follow-up time (-0.774, -0.935, -0.952, P<0.05). When the unstented segment of the abdominal aorta was evaluated (L 4-L 5), the average true lumen diameter at the level of celiac trunk increased significantly at 1 year by 13.7% ( P=0.007), however, the average false lumen diameter did not change over time ( P=0.406). The average true lumen diameter and false lumen diameter at the level of the lowest renal arteries increased over time as well, the average true lumen increased by 10.1%, and the average false lumen increased by 13.6% ( P=0.048, 0.017). Besides, the complete false lumen thrombosis rate of the stented segment of the descending thoracic aorta was higher than that of the unstented segment of the abdominal aorta.e complete false lumen thrombosis rate of the stented segment of the descending thoracic aorta was higher than that of the unstented segment of the abdominal aorta.

CONCLUSION

After receiving TEVAR-TSI, Stanford type B aortic dissection patients had high thrombosis absorption rate in the thoracic aortic segment covered by stent, and the aortic remodeling was more ideal. The aortic remodeling effect in the abdominal aortic segment not covered was not ideal, and the inner diameter of the abdominal aorta tended to increase. Therefore, close follow-up monitoring should be conducted.

Silent Brain Infarction After Endovascular Arch Procedures: Preliminary Results from the STEP Registry

OBJECTIVE

Few data exist concerning the rate of silent cerebral ischaemic events following endovascular treatment of the aortic arch. The objective of this work was to quantify these lesions using the STEP registry (NCT04489277).

METHODS

This multicentre retrospective cohort study included consecutive patients treated with an aortic endoprosthesis deployed in Ishimaru zone 0-3 and brain diffusion weighted magnetic resonance imaging (DW-MRI) within seven days following the procedure. DW-MRI was performed to identify the location and number of new silent brain infarctions (SBI). All endografts were carbon dioxide flushed prior to implantation.

RESULTS

The study population included 91 patients (mean age, 69 years; men, 64%) from two academic centres treated between September 2018 and January 2020. The procedure was elective in 71 patients (78%). The treatment was performed for a dissection, degenerative aneurysm, or other aortic disease in 44 (49%), 34 (37%), and 13 (14%) patients, respectively. Endografts were deployed in zone 0, 1, 2 or 3 in 23 (25%), 10 (11%), 47 (52%), and 11 (12%) patients, respectively. Endografts were branched (25%), fenestrated (17%), or tubular (58%). At 30 days, there were no deaths or clinical strokes. On cerebral DW-MRI, a total of 245 SBI were identified in 45 patients (50%). Lesions were in the left hemisphere in 63% of the patients (153/245), predominantly in the middle territory (94/245). Deployment in zone 0-1 (p = .026), placement of a branched or fenestrated endograft (p = .038), a proximal endoprosthesis diameter ≥ 40 mm (p = .038), and an urgent procedure (p = .005) were significantly associated with the presence of SBI on univariable analysis, while urgent procedure was found to be an independent predictor on multivariable analysis (binary logistic regression) (p = .002).

CONCLUSION

SBI following endovascular repair of the aortic arch is frequent, although there were no clinical strokes. Innovative strategies to reduce the risk of embolisation need to be developed.

The first commercial use of the Valiant Navion stent graft system for endovascular repair of a descending thoracic aortic aneurysm

Objectives

Thoracic endovascular aortic repair (TEVAR) is the standard of care for descending thoracic aortic aneurysms (DTAA), and newer generation stent grafts have significant design improvements compared to earlier generation devices.

Methods

We report the first commercial use of the Medtronic Valiant Navion stent graft for treatment of an 85-year-old woman with a 5.8 cm DTAA and a highly tortuous thoracic aorta.

Results

A percutaneous TEVAR was performed using a two-piece combination of the Valiant Navion FreeFlo and CoveredSeal stent graft configurations for zones 2–5 coverage. The devices were successfully delievered through highly tortuous anatomy and deployed, excluding the entire length of the aneurysm with precise landing, excellent apposition and no evidence of endoleak. The patient tolerated the procedure well and has had no stent graft-related complications through one-year follow-up.

Conclusions

Design enhancements such as a lower profile delivery system, better conformability, and a shorter tapered tip are some of the improvements to this third-generation TEVAR device. Coupled with the multiple configuration options available, this gives physicians a better tool to treat thoracic aortic pathologies in patients with challenging anatomy. The early results are encouraging, and evaluation of long-term outcomes will continue.

Bail-out thoracic endovascular aortic repair for incorrect deployment of frozen elephant trunk into the false lumen

We report a rare case of bail-out thoracic endovascular aortic repair after incorrect deployment of a frozen elephant trunk into the false lumen. A 54-year-old man presented to our department complaining of chest pain. Enhanced computed tomography revealed Stanford type A acute aortic dissection, which had a large entry site at the mid-descending aorta. Emergency total aortic arch replacement with a frozen elephant trunk was performed. Progressive intraoperative acidosis was observed. Immediate postoperative enhanced computed tomography showed that the distal end of the frozen elephant trunk was deployed into the false lumen through the initial tear at the proximal descending aorta. We performed emergency thoracic endovascular aortic repair through a fenestration made into the intimal flap using an Outback LTD re-entry device. The patient was discharged home on postoperative day 67 after a complete recovery.

Extrathoracic collaterals to critical segmental arteries after endovascular thoraco-abdominal aneurysm repair

OBJECTIVES

The risk of spinal cord injury after thoraco-abdominal aortic aneurysm repair increases when the segmental arteries (SAs) in the critical segment are sacrificed. Such critical SAs cannot be reconstructed when performing thoracic endovascular aortic repair (TEVAR). We aimed to elucidate extrathoracic collaterals to the critical SAs (T9-L1) that develop after TEVAR.

METHODS

Between 2006 and 2018, the critical SAs (T9-L1) of 38 patients were sacrificed during TEVAR. Nineteen of these patients who underwent multidetector row computed tomography 6 months after surgery were included (mean age 60 ± 13 years; 10 male; Crawford extent II:III, 14:5). We retrospectively assessed extrathoracic collaterals to the sacrificed critical SAs.

RESULTS

Ninety-four collaterals to the critical SAs were observed, originating from the subclavian (26/94), external iliac (50/94) and internal iliac (18/94) arteries. Twenty-five of the 26 (96%) collaterals from the subclavian artery were from its lateral descending branch, and 19 of the 26 (73%) collaterals fed into T9. Forty-three of the 50 (86%) collaterals from the external iliac artery were from its lateral ascending branch, and 25 of the 50 (50%) collaterals communicated with T11. Patients with a history of left thoracotomy (no collaterals in 6 patients) had fewer collaterals via the lateral descending branch of the left subclavian artery in comparison with the patients without (10 collaterals in 13 patients) (P = 0.009).

CONCLUSIONS

After critical SAs were sacrificed, extrathoracic collaterals developed with certain regularity. Previous left thoracotomy could influence the development of extrathoracic collaterals from the left subclavian artery.

Intraoperative heparin use is associated with reduced mortality without increasing hemorrhagic complications after thoracic endovascular aortic repair for blunt aortic injury

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) is an effective treatment of blunt thoracic aortic injury (BTAI). However, the risks and benefits of administering intraoperative heparin in trauma patients are not well-defined, especially with regard to bleeding complications.

METHODS

The Vascular Quality Initiative registry was queried from 2013 to 2019 to identify patients who had undergone TEVAR for BTAI with or without the administration of intraoperative heparin. Univariate analyses were performed with the Student t test, Fisher exact test, or χ² test, as appropriate. Multivariable logistic regression was then performed to assess the association of heparin with inpatient mortality.

RESULTS

A total of 655 patients were included, of whom most had presented with grade III (53.3%) or IV (20%) BTAI. Patients receiving heparin were less likely to have an injury severity score (ISS) of ≥15 (70.2% vs 90.5%; P < .0001) or major head or neck injury (39.6% vs 62.9%; P < .0001). Patients receiving heparin also had a lower incidence of inpatient death (5.1% vs 12.9%; P < .01). Across all injury grades, heparin use was not associated with the need for intraoperative transfusion or postoperative transfusion or the development of hematoma. In patients with grade III BTAI, the nonuse of heparin was associated with an increased risk of lower extremity embolization events (7.4% vs 1.8%; P < .05). On multivariable logistic regression analysis for inpatient mortality, intraoperative heparin use (odds ratio [OR], 0.31; 95% confidence interval [CI], 0.11-0.86; P < .05) and female gender (OR, 0.11; 95% CI, 0.11-0.86; P < .05) were associated with better survival, even after controlling for head and neck trauma and injury grade. In contrast, increased age (OR, 1.06; 95% CI, 1.03-1.1; P < .001), postoperative transfusion (OR, 1.06; 95% CI, 1.02-1.11; P < .01), higher ISS (OR, 1.04; 95% CI, 1.01-1.07; P < .05), postoperative dysrhythmia (OR, 4.48; 95% CI, 1.10-18.18; P < .05), and postoperative stroke or transient ischemic attack (OR, 5.54; 95% CI, 1.11-27.67; P < .05) were associated with increased odds of inpatient mortality.

CONCLUSIONS

Intraoperative heparin use was associated with reduced inpatient mortality for patients undergoing TEVAR for BTAI, including those with major head or neck trauma and high ISSs. Heparin use did not increase the risk of hemorrhagic complications across all injury grades. Also, in patients with grade III BTAI, heparin use was associated with a reduced risk of lower extremity embolic events. Heparin appears to be safe during TEVAR for BTAI and should be administered when no specific contraindication exists.