Factors Related to Late False Lumen Enlargement after Thoracic Stent-Graft Placement for Type B Aortic Dissection

Volumetric analysis in primary and residual type B aortic dissection treated with stented-assisted balloon-induced intimal disruption and relamination technique can predict aortic reintervention

OBJECTIVE

The aim of this study was to investigate the mid-term results of stented-assisted balloon-induced intimal disruption and relamination (STABILISE) in patients with aortic dissection with the implementation of volumetric analysis.

METHODS

This was a single-center retrospective analysis of prospectively collected data. From May 2017 to September 2022, 42 patients underwent STABILISE for acute complicated or subacute high-risk aortic dissection. STABILISE was completed with distal extended endovascular aortic repair in 24 patients. A computed tomography scan was performed at baseline, before hospital discharge, and at 1, 3, and 5 years. Perfused total aortic, true lumen, and false lumen volumes were assessed for thoracic, visceral, and aorto-iliac segment. The ratio between false lumen and total volume was named perfusion dissection index (PDI). Complete remodeling was defined as PDI = 0, and positive remodeling as PDI ≤0.1.

RESULTS

Technical success was 97.6%. No 30-day deaths, spinal cord injuries, or retrograde dissections were observed. Mean follow-up was 44 ± 19.4 months. Thoracic diameter was lower at last available computed tomography scan (36.7 vs 33.0 mm; P = .01). Aortic growth >5 mm was observed in 9.5% of the patients. Thoracic and visceral aortic complete remodeling were 92.8% and 83.3%, respectively, with no difference between acute and subacute group. Distal extended endovascular aortic repair significantly increased complete remodeling in the aorto-iliac segment, compared with STABILISE alone (69.6% vs 21.4%; P < .001). Freedom from vascular reinterventions at 3 years was 83.1% (95% confidence interval, 71.5%-96.6%). Total PDI ≤0.1 at first postoperative control was a predictor of vascular reinterventions (P < .0001).

CONCLUSIONS

STABILISE is a safe and feasible technique associated with high mid-term rates of complete remodeling in the thoracic and visceral aorta. Volumetric analysis allows the quantification of aortic remodeling and represents a predictor of aortic reinterventions.

Staging reinterventions for remodeling of residual aortic dissection: a single-center retrospective study

Objective

Inadequate remodeling of residual aortic dissection (RAD) following repair of Stanford A or B aortic dissections has been identified as a significant predictor of patient mortality. This study evaluates the short- to mid-term outcomes of staged reinterventions for RAD at a single center with prospective follow-up.

Methods

Data were retrospectively collected from patients with RAD who underwent staged reinterventions or received none-surgery treatment in the Cardiovascular Surgery Department of our hospital between July 2019 and December 2021. The cohort included 54 patients with residual distal aortic dissection post-primary surgery, comprising 28 who underwent open surgery and 26 who received thoracic endovascular aortic repair (TEVAR). Patients were divided into two groups: those who underwent staged stent interventions for distal dissection [staged reintervention (SR) group] and those who did not undergo surgery (non-surgery group). For the SR group, second or third staged stent interventions were performed. The study assessed distal remodeling of aortic dissection between the groups, focusing on endpoints such as mortality (both general and aortic-specific), occurrences of visceral branch occlusion, necessity for further interventions, and significant adverse events. Morphological changes were analyzed to determine the therapeutic impact.

Results

The study encompassed 54 participants, with 33 in the SR group and 21 in the non-surgical control group. Baseline demographics and clinical characteristics were statistically comparable across both groups. During an average follow-up of 31.5 ± 7.0 months, aortic-related mortality was 0% in both groups; all-cause mortality was 3% (one case) and 5% (one case) in the SR and control groups, respectively, with no statistically significant difference noted. In the SR group, a single patient experienced complications, including renal artery thrombosis, leading to diminished blood flow. An increased true lumen (TL) area and a decreased false lumen area at various aortic planes were observed in the SR group compared to the control group.

Conclusion

The staged reintervention strategy for treating RAD is safe and provides promising early results.

Clinical Outcomes and Factors Associated With Aortic Shrinkage After Thoracic Endovascular Aortic Repair for Aneurysmal Chronic Aortic Dissection

PURPOSE

The effectiveness of thoracic endovascular aortic repair (TEVAR) for chronic aortic dissection (AD) with aneurysmal degeneration remains controversial. We retrospectively investigated clinical outcomes and assessed predictors of aortic shrinkage after TEVAR for chronic aneurysmal AD.

MATERIALS AND METHODS

Between January 2010 and December 2021, 70 patients with double-barrel-type chronic AD were enrolled. Major intimal tears in thoracic aorta were covered by stent graft. Early and late clinical outcomes, and diameter change of downstream aorta during follow-up period were reviewed. Subsequently, factors associated with aortic shrinkage were assessed by logistic regression analysis.

RESULTS

Mean age was 63 (interquartile range [IQR]: 54-68) years, 54 (80%) men, median duration from AD onset was 4 (IQR: 1-10) years, and maximum aortic diameter was 53 (IQR: 49-58) mm. Supra-aortic debranching procedure was required in 57 (81%) patients. Early aorta-related death occurred in 2 (3%) patients. Both stroke and spinal cord ischemia occurred in 1 (2%) patient. Five-year freedom rates from aorta-related death and reintervention were 96% and 51%, respectively. Sixty-four patients underwent follow-up computed tomography (84%) 1 year after TEVAR, with 33 (52%) achieving aortic shrinkage. In multivariable analysis, duration from AD onset (per year) (odds ratio [OR]: 0.82, 0.70-0.97; p=0.017) and maximum aortic-diameter ratio between aortic arch and descending aorta (per 0.1) (morphologic index; OR: 1.34, 1.04-1.74; p=0.023) were independent aortic shrinkage predictors.

CONCLUSIONS

Thoracic endovascular aortic repair for chronic AD with aneurysmal degeneration achieved satisfactory survival outcomes, but with a considerable reintervention rate. Duration from AD onset and preoperative aortic morphology could affect post-TEVAR aortic shrinkage. Earlier intervention could lead to better aortic shrinkage.

CLINICAL IMPACT

Thoracic endovascular aortic repair for chronic aortic dissection with aneurysmal degeneration showed low incidence of early and late aorta-related death. By contrast, aortic shrinkage rate was low with high incidence of reintervention to the residual downstream aorta. According to the assessment of preoperative variables, chronicity and aortic morphology could predict postoperative aortic shrinkage.

Factors affecting distal false lumen enlargement after thoracic endovascular aortic repair for type B aortic dissection

Objective

To investigate the factors influencing distal false lumen enlargement after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection.

Materials and methods

Data were collected on patients with type B aortic dissection who underwent TEVAR from January 2008 to August 2022. Patients were divided into a distal aortic segmental enlargement (DSAE) group and a non-DSAE group based on whether the distal false lumen was dilated more than 5 mm on computed tomographic angiography (CTA) images. To analyze the independent influences on distal false lumen dilatation after TEVAR, the variables with a P value < 0.05 during univariate analysis were included in the binary logistic regression analysis model.

Results

A total of 335 patients were included in this study, with 85 in the DSAE group and 250 in the non-DSAE group. The mean age was 52.40 ± 11.34 years, 289 (86.27%) were male patients, and the median follow-up time was 6.41 (11.99-29.99) months. There were significant differences in Marfan syndrome, chronic obstructive pulmonary disease (COPD), and follow-up time between the two groups. In terms of morphology, there were statistically significant differences in the number of tears, the size of the primary tear, and the length of dissection between the two groups. Binary logistic regression analysis indicated that Marfan syndrome, COPD, and the primary tear size were associated with distal false lumen dilatation.

Conclusions

Marfan syndrome, COPD, and the primary tear size influence distal aortic segmental enlargement after TEVAR in type B aortic dissection patients.

Therapeutic window for obtaining favorable remodeling after thoracic endovascular aortic repair of type B aortic dissection

OBJECTIVE

The purpose of the present study was to determine the most appropriate timing for thoracic endovascular aortic repair (TEVAR) of type B aortic dissection (TBAD) in terms of remodeling of the aorta.

METHODS

A total of 41 patients who had undergone TEVAR for the treatment of aortic dissection were included in the present study. The patients were divided into two groups: those who had undergone TEVAR in the acute or subacute phase (group A) and those who had undergone TEVAR in the chronic phase (group B). The indications for TEVAR as the treatment of TBAD were the presence of aortic rupture or malperfusion of the aortic branches, a maximum aortic diameter of ≥40 mm on the initial diagnostic computed tomography scan, and/or expansion of the aorta of ≥5 mm within 3 months for acute and subacute TBAD. The indication was a maximum aortic diameter of ≥50 mm or expansion of the aorta of ≥5 mm within 1 year for chronic TBAD. The diameters of the aorta, true lumen, and false lumen were measured at the level of the most dilated part of the descending aorta (level M) and at the diaphragm (level D) on the computed tomography scan obtained before TEVAR and at the 2-year follow-up examination.

RESULTS

The median interval between TEVAR and the onset of TBAD was 0.2 month (interquartile range, 0.03-0.7 month) in group A (n = 21) and 32 months (interquartile range, 4.7-35.2 months) in group B (n = 20). Except for the aortic diameter at level D in group B, favorable remodeling was obtained at both levels in both groups. The diameter change ratio of the aorta at level D was significantly greater in group A than in group B (P = .02). Receiver operating characteristic curve analysis of the interval for a significant decrease in the aortic diameter at level D yielded 4.2 months as the optimal threshold for performing TEVAR (area under the curve, 0.859; 95% confidence interval, 0.7-1.0).

CONCLUSIONS

TEVAR for TBAD will result in favorable outcomes, irrespective of the timing of the procedure. However, it might be more effective to perform TEVAR within 4.2 months of the onset of TBAD, provided that the TEVAR procedure can be performed safely.

Secondary Interventions After TEVAR for Aortic Dissection

The goal of thoracic endograft placement in type B aortic dissection is to prevent aneurysmal degeneration and other complications. Although TEVAR is a highly effective tool for managing type B aortic dissection, many patients will require additional interventions. In this article, we present a case-based review of techniques for the management of persistent false lumen perfusion and stent-graft induced new entry tears after TEVAR for aortic dissection.

Short Term Outcomes of Distal Extended EndoVascular Aortic Repair (DEEVAR) Petticoat in Acute and Subacute Complicated Type B Aortic Dissection

OBJECTIVE

The aim of this study was to evaluate the peri-operative and short term results of institutional experience with the Distal Extended EndoVascular Aortic Repair PETTICOAT (DEEVAR PETTICOAT) procedure.

METHODS

This was a single centre, observational study. From January 2015 to December 2019, 53 patients were admitted to the institution for treatment of acute and subacute complicated type B aortic dissection. Among them, data on 16 patients deemed suitable for a PETTICOAT procedure extended at infrarenal and iliac level by means of a bifurcated endograft were prospectively collected. Patients with persistent pain, visceral or lower limb malperfusion, true lumen collapse, and distal extension with computed tomography angiography (CTA) evidence of entry tears in the infrarenal or iliac zone were included. A CTA scan was performed in all patients at the baseline, before hospital discharge and then at six and 12 months post-operatively to assess aortic remodelling. Complete aortic remodelling was defined as stable aortic size (maximum enlargement < 5 mm) with complete true lumen re-expansion and complete false lumen exclusion or disappearance.

RESULTS

Technical success was obtained in all patients. One patient (7%) had intra-operative infrarenal aortic rupture during balloon dilation of the distal end of the bare stent, successfully treated by deployment of a bifurcated endograft. Additional covered stenting of the visceral arteries was necessary in nine patients (56%) and malperfusion resolved immediately in all cases. There were no spinal cord ischaemia or other peri-procedural complications, and no post-operative death, stroke, paraplegia/paraparesis, or acute renal failure was observed. Follow up ranged from one month to 24 months (median 7.5 months). One patient (7%) with a history of drug abuse died from sepsis. At the last CTA check, all patients showed complete remodelling of the thoraco-abdominal aorta and iliac arteries without vessel enlargement.

CONCLUSION

The present findings suggest that the DEEVAR PETTICOAT procedure provides effective sealing of all distal tears without increased risk of major peri-procedural complications. Further studies with larger number of patients and longer follow up are needed to confirm the safety and durability of this technique.

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).

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.

Twelve-Month Computed Tomography Follow-Up after Thoracic Endovascular Repair for Acute Complicated Aortic Dissection

BACKGROUND

To explore the impact of thoracic endovascular aortic repair (TEVAR) on aortic remodeling (AR) and the relationship between AR and complications after TEVAR.

METHODS

A total of 56 patients (2 type IIIA aortic dissection [AD] and 54 type IIIB AD) with complicated acute type B aortic dissection suitable for TEVAR were prospectively enrolled. There were 44 men (78%) and 12 women (22%) with an average age of 54 ± 13.8 years. Aortic enhanced computed tomography (CT) was performed pre-TEVAR and 3, 6, and 12 months postoperatively. The morphological changes in AR, namely aortic volume and false lumen thrombosis, were obtained by analyzing the CT data. The effect of TEVAR on AR was determined by the morphological changes in the aorta. The relationship between AR index, false lumen thrombosis, and complications was analyzed.

RESULTS

The volume of the thoracic aortic true lumen gradually increased post-TEVAR, whereas the volume of the thoracic aortic false lumen gradually decreased. The volume of abdominal aortic total lumen and false lumen increased 6 months postoperatively. The AR index increased significantly 3 months postoperatively, which was negatively correlated with complications and mortality. The thoracic and abdominal aortic false lumen thrombosis developed gradually after TEVAR, and the degree of thoracic aortic false lumen thrombosis was negatively correlated with complications and mortality.

CONCLUSIONS

TEVAR promotes AR. AR index and the degree of thoracic aortic false lumen thrombosis can serve as predictors of complications and mortality.

Geometric Analysis of Type B Aortic Dissections Shows Aortic Remodeling After Intervention Using Multilayer Stents

Recently, multilayer stents for type B aortic dissections (TBAD) have been proposed to decrease false lumen flow, increase and streamline true lumen flow, and retain branch vessel patency. We aimed to provide a protocol with standardized techniques to investigate aortic remodeling of TBAD by multilayer flow modulators (MFM) in static geometric and hemodynamic analyses. Combining existing literature and new insights, a standardized protocol was designed. Using pre- and postoperative CT scans, geometric models were constructed, lumen dimensions were calculated, computational fluid dynamics (CFD) models were composed, and velocity and pressures were calculated. Sixteen TBAD cases treated with MFM were included for analysis. For each case, aortic remodeling was analyzed using post-processing medical imaging software. After 3D models were created, geometrical anatomical measurements were performed, and meshes for finite element analysis were generated. MFM cases were compared pre- and postoperatively; true lumen volumes increased (p < 0.001), false lumen volumes decreased (p = 0.001), true lumen diameter at the plane of maximum compression (PMC) increased (p < 0.001), and false lumen index decreased (p = 0.008). True lumen flow was streamlined, and the overall fluid velocity and pressures decreased (p < 0.001 and p = 0.006, respectively). This protocol provided a standardized method to evaluate the effects of MFM treatments in TBAD on geometric analyses, PMC, and CFD outcomes.

Computed tomography-based hemodynamic index for aortic dissection

OBJECTIVE

In this study we aimed to propose a new computed tomography-based hemodynamic indicator to quantify the functional significance of aortic dissection and predict post intervention luminal remodeling.

METHODS

Computational hemodynamics and 3D structural analyses were conducted in 51 patients with type B aortic dissection, at initial presentation and at approximately 1 month, 3 months, and 1 year post intervention. A functional index was proposed on the basis of luminal pressure difference. Statistical relationships between the proposed indicator and longitudinal luminal development were analyzed.

RESULTS

The computed luminal pressure difference (true lumen pressure minus false lumen pressure) varied overall from positive to negative along the aorta. The first balance position at which the pressure difference equals 0 was proposed as the functional indicator. A more distally located first balance position indicated better functional status. Implantation of stent graft distally shifted this balance position. Patients with the balance position shifted out of the dissected region (43%) presented the highest functional improvement after intervention; whereas those with the balance position shifted to the abdominal region (25%) showed unsatisfactory results. The magnitude of distal shifting of the first balance position at 3 months post intervention was statistically related to the subsequent true lumen expansion and false lumen reduction.

CONCLUSIONS

The first balance position of luminal pressure difference quantified the hemodynamic status of the dissected aorta. The magnitude of distal shifting of the balance position after intervention was associated with functional improvement and might be used predict longitudinal aortic remodeling.

Midterm prognosis of type B aortic dissection with and without dissecting aneurysm of descending thoracic aorta after endovascular repair

Few studies support guidelines for the use of thoracic endovascular aortic repair (TEVAR) to address type B aortic dissection (TBAD) coexisting with descending thoracic aortic dissection and aneurysm (dTADA). This cohort study investigated midterm outcomes of TBAD with dTADA (dTADA group, n = 31) and without dTADA (non-dTADA group, n = 98) after TEVAR. Compared with the non-dTADA group, the dTADA group exhibited higher incidences of type Ia endoleak (29.0% vs. 3.1%, P < 0.001) and reintervention (16.1% vs. 5.1%, P = 0.045). The completely thrombosed rate of the thoracic false lumen was significantly lower in the dTADA group than in the non-dTADA group (45.2% vs. 80.6%, P < 0.001). Although the two groups exhibited similar mortality rates, TBAD coexisting with no regressive dTADA after TEVAR was an independent predictor of mortality (HR: 15.52, 95% CI: 1.614-149.233, P = 0.018). Moreover, the change percentages of false lumen retraction and true lumen re-expansion in the dTADA group were significantly inferior to those of the non-dTADA group at levels of 4th, 6th, 8th and 10th thoracic vertebra throughout follow-up. In conclusion, in the presence of preexisting dTADA, the failure of the dTADA to regress after TEVAR is associated with lower survival and a higher risk of reintervention.