Prevalence of the Computed Tomographic Morphological DISSECT Predictors in Uncomplicated Stanford Type B Aortic Dissection

Predicting adverse events after thoracic endovascular aortic repair for patients with type B aortic dissection

The potential of adverse events (AEs) after thoracic endovascular aortic repair (TEVAR) in patients with type B aortic dissection (TBAD) has been reported. To avoid the occurrence of AEs, it is important to recognize high-risk population for prevention in advance. The data of 261 patients with TBAD who received TEVAR between June 2017 and June 2021 at our medical center were retrospectively reviewed. After the implementation of exclusion criteria, 172 patients were finally included, and after 2.8 years (range from 1 day to 5.8 years) of follow up, they were divided into AEs (n = 41) and non-AEs (n = 131) groups. We identified the predictors of AEs, and a prediction model was constructed to calculate the specific risk of postoperative AEs at 1, 2, and 3 years, and to stratify patients into high-risk (n = 78) and low-risk (n = 94) group. The prediction model included seven predictors: Age > 75 years, Lower extremity malperfusion (LEM), NT-proBNP > 330 pg/ml, None distal tear, the ratio between the diameter of the ascending aorta and descending aorta (A/D ratio) > 1.2, the ratio of the area of the false lumen to the total aorta (FL ratio) > 64%, and acute TEVAR, which exhibited excellent predictive accuracy performance and discriminatory ability with C statistic of 82.3% (95% CI 77.3-89.2%). The prediction model was contributed to identify high-risk patients of postoperative AEs, which may serve to achievement of personalized treatment and follow-up plans for patients.

Staged surgically created type B aortic dissection model with endovascular reintervention for different morphological features

OBJECTIVES

Understanding morphology and how this relates to treatment strategy is critical for achieving remodelling in aortic dissection. A controllable and reproducible large animal model is required for investigating new therapeutic devices and interventions.

METHODS

Our experimental protocol involved the development of surgically created type B aortic dissection (TBAD) and endovascular reintervention-induced TBAD porcine models. The sample was randomly divided into 2 groups: 1 underwent a secondary tear creation (STC) procedure and the other underwent a false lumen extension (FLE) procedure. Anatomical features were observed at 1 and 3 months, and 2 animals in each group were euthanized at 3 months after the procedures. The aorta and main branches were harvested en bloc, cross-sectioned and prepared for histological examination.

RESULTS

All surgically created TBAD models were successfully generated, and no unintended complications occurred. The endovascular reintervention-induced TBAD model was successfully created in 11 of 12 animals, with 6 in the STC group and 5 in the FLE group. In the STC group, the intraoperative mean diameter of the new secondary tear was 7.23 mm, and a slight increase was observed at first 30 days (P = 0.0026). In the FLE group, the intraoperative new propagation length was (235.80 ± 84.94) mm. The FL propagation length at the 1-month follow-up was significantly longer than that measured intraoperatively (P = 0.0362). Histological evaluation demonstrated that the elastic fibres in the media layer of the aortic wall were disrupted and appeared to be significantly stretched on the adventitial side of the false lumen.

CONCLUSIONS

Our endovascular reintervention is a reliable, minimally invasive approach for producing specific TBAD models with different morphologies.

Early Thoracic Endovascular Aortic Repair of Uncomplicated Type B Thoracic Aortic Dissection: An Aorta Team Approach

BACKGROUND

 Although uncomplicated Type B aortic dissection (uTBAD) is traditionally treated with optimal medical therapy (OMT) as per guidelines, recent studies, performed primarily in interventional radiology or surgical operating rooms, suggest superiority of thoracic endovascular aortic repair (TEVAR) over OMT due to recent advancements in endovascular technologies. We report a large, single-center, case control study of TEVAR versus OMT in this population, undertaken solely in a cardiac catheterization laboratory (CCL) with a cardiologist and surgeon. We aimed to determine if TEVAR for uTBAD results in better outcomes compared with OMT.

METHODS

 This was a retrospective chart review of all patients with uTBAD during the last 13 years, with 46 cases (TEVAR group) and 56 controls (OMT group).

RESULTS

 In the TEVAR group, the procedure duration of 2.5 hours resulted in 100% procedural success for stent placement, with 63% undergoing protective left subclavian artery bypass, 0% mortality or stroke, and a lower readmission rate (1 vs. 2%; p = 0.04 in early TEVAR cases), but a longer length of stay (12.9 vs. 8.5 days: p = 0.006). The risk of all-cause long-term mortality was markedly reduced in the TEVAR group (RR = 0.38; p = 0.01), irrespective of early (<14 days) versus late intervention. On follow-up computed tomography imaging, the false lumen stabilized or decreased in 85% of cases, irrespective of intervention timing.

CONCLUSION

 TEVAR performed solely in the CCL is safe and effective, with lower all-cause mortality than OMT. These data, in collaboration with previous data on TEVAR in different settings, call for consideration of an update of practice guidelines.

Acute aortic dissection: evidence, uncertainties, and future therapies

Remarkable progress has become especially apparent in aortic medicine in the last few decades, leading to essential changes in how thoracic aortic dissection is understood and treated. This state-of-the-art review article addresses the mechanisms of acute aortic dissection, explaining the role of its primary entry location, proximal, and distal dissection extension in their clinical presentation and impact on the decision-making process towards the best treatment approach. The latest evidence on novel treatment methods for acute aortic syndromes is presented, and the diverse dissection classification systems that remain uncertain are discussed, which reveals the need for shared terminology and more clarity. Finally, future aspects are discussed in treating acute aortic dissection, such as the endovascular treatment of aortic dissection Type A and biomarkers for acute aortic syndromes.

Current Understanding of Aortic Dissection

The aorta is the largest artery in the body, delivering oxygenated blood from the left ventricle to all organs. Dissection of the aorta is a lethal condition caused by a tear in the intimal layer of the aorta, followed by blood loss within the aortic wall and separation of the layers to full dissection. The aorta can be affected by a wide range of causes including acute conditions such as trauma and mechanical damage; and genetic conditions such as arterial hypertension, dyslipidaemia, and connective tissue disorders; all increasing the risk of dissection. Both rapid diagnostic recognition and advanced multidisciplinary treatment are critical in managing aortic dissection patients. The treatment depends on the severity and location of the dissection. Open surgical repair is the gold standard of treatment for dissections located to the proximal part of the aorta and the arch, while endovascular interventions are recommended for most distal or type B aortic dissections. In this review article, we examine the epidemiology, pathophysiology, contemporary diagnoses, and management of aortic dissection.

Age-related differences in acute aortic dissection

OBJECTIVE

The present study investigated the differences in clinical characteristics, treatments, and outcomes of patients with acute aortic dissection (AAD) in different age groups.

METHODS

The present single-center retrospective study was conducted from August 2014 to August 2020. The patients were divided into three groups: age <45 years (young group), age 45 to 59 years (middle-age group), and age >59 years (elderly group). Type A (TAAD) and type B (TBAD) aortic dissection were evaluated separately using the latest definitions.

RESULTS

The mean age at onset was 52.4 years in our cohort of 602 patients. The young group included a large proportion of male patients (86%). The body mass index and body surface area were higher in the young group. The proportion of non-true lumen blood supply of branches on the abdominal aorta in the young group (27%-55%) was greater than that in the others. In the young group, the distal extent of dissection in 84% of TAAD and 89% of TBAD exceeded the abdominal aortic branch cluster (AABC) compared with 36% of TAAD and 58% of TBAD in the elderly group. The multivariate analysis revealed that age <45 years (odds ratio, 5.15; P < .001) and D-dimer level (odds ratio, 1.05; P = .001) were risk factors for intimal flap tear exceeding the AABC. The proportion of visceral and lower limb malperfusion increased from 4.8% to 36.9% as the intimal flap tear exceeded the AABC.

CONCLUSIONS

Compared with middle-age and elderly patients, young patients with AAD had two characteristics (ie, obesity and an intimal flap that had frequently exceeded the branches of the aorta). These two factors resulted in a greater proportion of non-true lumen blood supply, increased visceral and lower limb malperfusion, and an increase in potential associated risks.

Review of Studies Reporting the Incidence of Acute Type B Aortic Dissection

Aortic dissection (AD) causes more deaths each year in the United Kingdom than road traffic collisions. Yet the incidence of AD is not known. The management of acute type B AD (TBAD) is changing, with the greater use of thoracic aortic stent grafts (TEVAR) in treatment and fewer open surgical procedures performed. The study’s aim is to review the worldwide, English language published, literature on acute TBAD incidence and treatment, to report on its strengths and limitations, and better understand changes in incidence over time and between countries. Thirty-one studies were identified that focus on the epidemiology and treatment of TBAD. Eight of these studies report the incidence of acute TBAD as between of 0.5–6.3 per 100,000 person years. Hospital admissions for aortic dissection are reported to be increasing in six studies and stable in one study. The proportion of patients with TBAD operated on varies between studies (range 13% to 76%). Studies identify patient age (median 51–77 years), gender (range 48%–81% male) and prevalence of cardio-vascular risk factors, specifically hypertension, in the populations studied as independent factors influencing aortic dissection incidence. Treatment of acute TBAD remains largely conservative with analgesia, hypertension control and serial cross-sectional imaging (range 24%–87% TBAD medically treated). The use of TEVAR to treat acute AD is increasing worldwide (range 13%–76% TBAD treated with TEVAR). The incidence of TBAD is under-reported due to out of hospital deaths, variable clinical presentation (miss-diagnosis) and coding errors. Importantly for research, the single International Classification of Diseases (ICD) code for aortic dissection, I17.0, does not distinguish between acute, chronic, type A or type B dissection types. Similarly, the OPCS Classification of Interventions and Procedures version 4 (OPCS-4) codes for TEVAR, L27.4 and L28.4, do not distinguish between acute and chronic AD presentation, unlike the codes for open thoracic aortic replacement. Standardised reporting of aortic dissection type, and the urgency of both the initial presentation (acute or chronic) and treatment (emergency, urgent or planned) in future studies would allow more meaningful comparisons between populations.

Preliminary results of spot-stent grafting in Stanford type B aortic dissection and intramural haematoma

OBJECTIVES

METHODS

Patients undergoing thoracic endovascular aortic repair (TEVAR) for acute/subacute aortic dissection Stanford type B/intramural haematoma Stanford type B between 1997 and 2018 were identified from a prospectively maintained institutional database. In a total of 183 cases, 22 patients (7 women; median age 62 years; range 35–79 years) received SSG. The primary study end point was technical success. The primary morphological end point was false lumen thrombosis/aortic remodelling. Secondary end points were TEVAR-related mortality/morbidity and reinterventions. The median follow-up was 28.5 months (5 days–15.6 years).

RESULTS

The primary technical success rate was 100% (22/22). During follow-up, false lumen thrombosis was seen in 21 patients (95.5%) at a median of 6 days (0 days to 2.7 years) after the index procedure (limited/extended false lumen thrombosis: n = 9 vs 12). Aortic remodelling was achieved in 15 of 22 patients (68.2%) at a median of 360 days (3 days to 7.2 years). Limited/extended remodelling was observed in 8/15 and 7/15, respectively. Retrograde dissection or stent graft-induced new entry was not observed. No stroke or spinal cord injury occurred. Reinterventions were performed in 4/22 cases. The in-hospital mortality and 30-day mortality were 0%. Overall mortality during the follow-up period was 22.7% (5/22).

CONCLUSIONS

This study shows favourable technical and morphological results for SSG in selected patients with acute/subacute aortic dissection Stanford type B/intramural haematoma Stanford type B. Patient allocation to SSG remains individual. Prospective large-scale long-term data may allow refinement of the application.

Distal Stent Graft-Induced New Entry After TEVAR or FET: Insights Into a New Disease From EuREC

BACKGROUND

The study sought to learn about incidence and reasons for distal stent graft-induced new entry (dSINE) after thoracic endovascular aortic repair (TEVAR) or after frozen elephant trunk (FET) implantation, and develop prevention algorithms.

METHODS

In an analysis of an international multicenter registry (EuREC [European Registry of Endovascular Aortic Repair Complications] registry), we found 69 dSINE patients of 1430 (4.8%) TEVAR patients with type B aortic dissection and 6 dSINE patients of 100 (6%) patients after the FET procedure for aortic dissection with secondary morphological comparison.

RESULTS

The underlying aortic pathology was acute type B aortic dissection in 33 (44%) patients, subacute or chronic type B aortic dissection in 34 (45%) patients, acute type A aortic dissection in 3 patients and remaining dissection after type A repair in 3 (8%) patients, and acute type B intramural hematoma in 2 (3%) patients. dSINE occurred in 4.4% of patients in the acute setting and in 4.9% of patients in the subacute or chronic setting after TEVAR. After the FET procedure, dSINE occurred in 5.3% of patients in the acute setting and in 6.5% of patients in the chronic setting. The interval between TEVAR or FET and the diagnosis of dSINE was 489 ± 681 days. Follow-up after dSINE was 1340 ± 1151 days, and 4 (5%) patients developed recurrence of dSINE. Morphological analysis between patients after TEVAR with and without dSINE showed a smaller true lumen diameter, a more accentuated oval true lumen morphology, and a higher degree of stent graft oversizing in patients who developed dSINE.

CONCLUSIONS

dSINE after TEVAR or FET is not rare and occurs with similar incidence after acute and chronic aortic dissection (early and late). Avoiding oversizing in the acute and chronic settings as well as carefully selecting patients for TEVAR in postdissection aneurysmal formation will aid in reducing the incidence of dSINE to a minimum.

Dynamic Indicators That Impact the Outcomes of Thoracic Endovascular Aortic Repair in Complicated Type B Aortic Dissection

PURPOSE

To investigate dynamic variables obtained from retrospective computed tomography angiography for ability to predict thoracic endovascular aortic repair (TEVAR) outcomes in patients with complicated type B aortic dissection (cTBAD).

MATERIALS AND METHODS

Seventy-nine patients with cTBAD who received TEVAR from March 2009 to June 2018 were retrospectively enrolled. Relative true lumen area (r-TLA) was computed at the level of tracheal bifurcation every 5% of all R-R intervals. Parameters that reflect the state of intimal motion were evaluated, including difference between maximum and minimum r-TLA (D-TLA) and true lumen collapse. The endpoints comprised early (≤ 30 days) and late (> 30 days) outcomes after intervention.

RESULTS

Overall early mortality rate was 13.9% (11/79), and early adverse events rate was 24.1% (19/79). Patients who received TEVAR within 2 days of symptom onset demonstrated the worst outcomes. A longer time of r-TLA < 25% in 1 cardiac cycle (P = .049) and larger D-TLA (P < .001) were correlated to an increased early death. In addition, D-TLA was an independent predictor of early mortality. Area under the curve of D-TLA was 0.849 (95% confidence interval 0.730-0.967) for predicting early mortality and 0.742 (95% CI 0.611-0.873) for predicting early adverse events. Survival and event-free survival rates during follow-up were decreased in the D-TLA > 21.5% group compared with the D-TLA ≤ 21.5% group (all P < .001).

CONCLUSIONS

Larger D-TLA is correlated with worse postoperative outcomes and might be a crucial parameter for future risk stratification in patients with cTBAD.