Aortic Remodeling as a Prognostic Factor for Late Aortic Events After Thoracic Endovascular Aortic Repair in Type B Aortic Dissection With Patent False Lumen

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Successful "PETTICOAT" procedure assisted by aortic angioscopy for complicated type B aortic dissection: Case report

INTRODUCTION

Thoracic endovascular aortic repair (TEVAR) is a useful treatment for acute type B aortic dissection (TBAD). A PETTICOAT (Provisional ExTension to Induce COmplete ATtachment) procedure can be an alternative surgical option for a patent false lumen. Non-obstructive aortic angioscopy is an attractive modality that can visualize the aortic intima for things such as entry or re-entry tears that are difficult to detect with computed tomography (CT). Herein, we describe a successful PETTICOAT procedure assisted by aortic angioscopy for subacute TBAD complicated by lower limb ischemia.

PRESENTATION OF CASE

A 63-year-old man who had been treated with conservative therapy for subacute TBAD had intermittent claudication. Enhanced CT revealed a primary entry tear at the distal arch, and the true lumen at the thoracoabdominal level was narrowed by the patent false lumen. Therefore, the PETTICOAT procedure was performed. The postoperative course was uneventful, with normalized lower limb pressure.

DISCUSSION

Although PETTICOAT procedure is effective for treating complicated TBAD, there is no consensus on where and how far the proximal stent graft or distal bare stent should be implanted. Non-obstructive aortic angioscopy during PETTICOAT is useful to detect and cover the entry and re-entry tears. The PETTICOAT procedure assisted by aortic angioscopy could contribute to determining the appropriate coverage range of the stent graft.

CONCLUSION

Aortic angioscopy could contribute to the surgical success of PETTICOAT procedure for complicated subacute TBAD.

Managing False Lumen Patency in Chronic Thoracic Aortic Dissecting Aneurysms With Coil Embolization

Thoracic endovascular aortic repair has become the preferred modality of treatment of complicated type B aortic dissections. However, persistent pressurization of the false lumen can lead to negative aortic remodeling with aneurysmal dilation. Described herein is the coil embolization technique that can be used to manage this complication and a review of the literature on the recent development of management options.

Rapid Morphological Measurement Method of Aortic Dissection Stent Based on Spatial Observation Point Set

OBJECTIVES

Post-operative stent morphology of aortic dissection patients is important for performing clinical diagnosis and prognostic assessment. However, stent morphologies still need to be manually measured, which is a process prone to errors, high time consumption and difficulty in exploiting inter-data associations. Herein, we propose a method based on the stepwise combination of basic, non-divisible data sets to quickly obtain morphological parameters with high accuracy.

METHODS

We performed the 3D reconstruction of 109 post-operative follow-up CT image data from 26 patients using mimics software. By extracting the spatial locations of the basic morphological observation points on the stent, we defined a basic and non-reducible set of observation points. Further, we implemented a fully automatic stent segmentation and an observation point extraction algorithm. We analyzed the stability and accuracy of the algorithms on a test set containing 8 cases and 408 points. Based on this dataset, we calculated three morphological parameters of different complexity for the different spatial structural features exhibited by the stent. Finally, we compared the two measurement schemes in four aspects: data variability, data stability, statistical process complexity and algorithmic error.

RESULTS

The statistical results of the two methods on two low-complexity morphological parameters (spatial position of stent end and vascular stent end-slip volume) show good agreement (n = 26, P₁, P₂ < 0.001, r₁ = 0.992, r₂ = 0.988). The statistics of the proposed method for the morphological parameters of medium complexity (proximal support ring feature diameter and distal support ring feature diameter) avoid the errors caused by manual extraction, and the magnitude of this correction to the traditional method does not exceed 4 mm with an average correction of 1.38 mm. Meanwhile, our proposed automatic observation point extraction method has only 2.2% error rate on the test set, and the average spatial distance from the manually marked observation points is 0.73 mm. Thus, the proposed method is able to rapidly and accurately measure the stent circumferential deflection angle, which is highly complex and cannot be measured using traditional methods.

CONCLUSIONS

The proposed method can significantly reduce the statistical observation time and information processing cost compared to the traditional morphological observation methods. Moreover, when new morphological parameters are required, one can quickly and accurately obtain the target parameters by new "combinatorial functions." Iterative modification of the data set itself is avoided.

Preoperative systemic inflammatory response index predicts long-term outcomes in type B aortic dissection after endovascular repair

Objectives

Inflammation is a hallmark of the initial development and progression of aortic dissection. This study aimed to investigate the value of preoperative inflammatory biomarkers in predicting aorta-related adverse events (AAEs) after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection.

Methods

We included all patients who underwent TEVAR for type B aortic dissection between November 2016 and November 2020 in this single-center, retrospective cohort study. Patients were divided into two groups: the AAEs group (n = 75) and the non-AAEs group (n = 126). Preoperative inflammatory biomarkers were recorded, including neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), systemic immune inflammation index (SII), and systemic inflammatory response index (SIRI). Patients were followed-up for the development of AAEs. Prediction accuracy of inflammatory biomarkers for AAEs were evaluated using the area under the receiver operating characteristic curves.

Results

This study included 201 patients, of whom 80.0% were men, with a mean age of 59.1 ± 12.5 years. A total of 75 patients developed AAEs after TEVAR. The AUCs of NLR, MLR, PLR, SII, and SIRI for AAEs were.746,.782,.534,.625 and.807, respectively. Age and SIRI were independent risk factors for the AAEs after TEVAR (HR 3.264, p <.001; HR 4.281, p <.001, respectively). Survival analysis revealed significantly lower AAE-free status in patients with preoperative SIRI > = 4 (p <.001).

Conclusion

Increased preoperative SIRI and age are independent risk factors for AAEs after TEVAR in type B aortic dissection.

Thoracic endovascular aortic repair of highly tapered type B aortic dissection with proximal tapered stent grafts and distal restrictive stent grafts

OBJECTIVES

This study evaluated aortic remodeling in highly tapered type B aortic dissection (TBAD) patients who underwent thoracic endovascular aortic repair (TEVAR) with a proximal tapered stent graft plus a distal restrictive stent graft to maximize thoracic coverage while avoiding distal excessive oversizing.

METHODS

Thirty-four patients presenting with highly tapered TABD were randomized to restricted TEVAR (r-TEVAR) and standard TEVAR groups. Highly tapered TBAD was defined as the maximal diameter of the true lumen at proximal and distal thoracic aorta landing zone tapers greater than 8 mm or taper ratio greater than 20%. Patients in the r-TEVAR group underwent proximal tapered stent grafts plus distal restrictive stent grafts to match the taper ratio of the descending thoracic aorta (DTA) and extend the length of stent coverage. Patients in the standard TEVAR group underwent proximal tapered stent grafts implantation without distal restrictive stent grafts. Aortic remodeling was estimated by computed tomography angiography (CTA) during the follow-up.

RESULTS

In total, 16 patients underwent r-TEVAR, and 18 patients underwent standard TEVAR. The taper ratio of the stent graft matched the DTA in the r-TEVAR group (24.7±3.4% vs. 27.3±4.2%, P=0.068) but did not match that in the standard TEVAR group (13.5±3.3% vs. 30.5±9.6%, P<0.001). The length of stent graft coverage in the r-TEVAR group was longer than that in the standard TEVAR group (220.4±21.1 mm vs. 175.3±17.8 mm, P<0.001). Compared with the standard TEVAR group, the r-TEVAR group had better complete remodeling of the DTA at 6 months (40% vs. 5.6%, P=0.03), 12 months (60% vs. 16.7%, P=0.027) and 24 months (78.6% vs. 41.2%, P=0.036) after the operation. There was no difference in the cumulative survival rate between the r-TEVAR and standard TEVAR groups (P=0.166).

CONCLUSIONS

r-TEVAR with overlapping proximal tapered stent grafts and distal restrictive stent grafts can match the taper of highly tapered TABD, extend the length of stent graft coverage, and lead to better remodeling of the DTA than standard TEVAR.

The Necessity to Seal the Re-Entry Tears of Aortic Dissection After TEVAR: A Hemodynamic Indicator

Thoracic endovascular aortic repair (TEVAR) is a common treatment for Stanford type B aortic dissection (TBAD). However, re-entry tears might be found distal to the stented region which transports blood between the true and false lumens. Sealing the re-entry tears, especially for the thoracic tears, could further reduce blood perfusion to the false lumen; however, it might also bring risks by re-intervention or surgery. Wise determination of the necessity to seal the re-entry tears is needed. In this study, patient-specific models of TBAD were reconstructed, and the modified models were established by virtually excluding the thoracic re-entries. Computational hemodynamics was investigated, and the variation of the functional index and first balance position (FBP) of the luminal pressure difference, due to the sealing of the re-entries, was reported. The results showed that the direction of the net flow through the unstented thoracic re-entries varied among cases. Excluding the re-entries with the net flow toward the false lumen may induce the FBP moving distally and the relative particle residence time increasing in the false lumen. This study preliminarily demonstrated that the hemodynamic status of the re-entry tears might serve as an indicator to the necessity of sealing. By quantifying the through-tear flow exchange and shift of FBP, one can predict the hemodynamic benefit by sealing the thoracic re-entries and thus wisely determine the necessity of further interventional management.

Long-Term Aortic Remodeling After Thoracic Endovascular Aortic Repair of Acute, Subacute, and Chronic Type B Dissections

Objective

This study aimed to investigate the characteristics and predictors of aortic remodeling over a long-term follow-up period after thoracic endovascular aortic repair (TEVAR) for acute, subacute, and chronic type B aortic dissections (TBADs).

Methods

Patients who underwent TEVAR for TBAD from July 2011 to December 2013 were included, and relevant data were retrospectively analyzed.

Results

After TEVAR, the true lumen (TL) dimension increased and the false lumen (FL) dimension decreased or did not change over a 5-year follow-up period in all three temporal groups. Shrinkage proportion of the thoracic aorta was the highest in the subacute group (acute, 28.1%; subacute, 39.1%; and chronic, 17.4%; p = 0.048), while abdominal expansion showed no significant differences among the groups (acute, 29.6%; subacute, 40.5%; and chronic, 44.4%; p = 0.502). The chronic group had a rate of complete FL regression, which is lower than the subacute or acute group at all anatomic sections, with significant differences only in the stented section (chronic, 21.7%; acute, 92.2%; and subacute, 80.4%; p < 0.05) and in the distal thoracic aortic section (chronic, 13.0%; acute, 31.1%; and subacute, 50.0%; p < 0.05). Logistic regression analysis demonstrated that chronic dissection, TL compression, endoleak, the number of branches from FL, and the number of residual tears affected optimal FL remodeling.

Conclusion

The present study provides data on aortic remodeling of TBAD after TEVAR during a long-term follow-up period. The features and risk factors of aortic remodeling in the acute, subacute, and chronic phases are different in different aortic segments. These findings may have implications in the timing of TEVAR.

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

OBJECTIVE

The new Society for Vascular Surgery/Society for Thoracic Surgery reporting standards for type B aortic dissection (TBAD) categorize clinical presentations of aortic dissection into uncomplicated, high-risk features (HRF), and complicated groups. Although it is accepted that complicated dissections require immediate repair, the optimal timing of repair for HRF has yet to be established. This study aims to identify the ideal timing of thoracic endovascular aortic repair (TEVAR) for HRF, as well as outcomes associated with specific HRF.

METHODS

The Vascular Quality Initiative was queried for TEVARs performed for acute and subacute TBAD with HRF from 2014 to 2020. Rupture, malperfusion, and uncomplicated patients were excluded. HRF were defined per the guidelines as refractory hypertension, pain, or rapid expansion/aneurysm of more than 40 mm. The primary outcomes were in-hospital/30-day mortality and 1-year survival with primary exposure variables being days from symptoms to repair and number of HRFs. Secondary outcomes were spinal cord ischemia, stroke, and retrograde type A dissection (RTAD).

RESULTS

Of the 1100 patients who met inclusion criteria, 811 had one HRF, 249 had two, and 40 had three. There were no significant differences in primary or secondary outcomes based on number of HRFs. There were 309 patients who underwent repair at 0 to 2 days, 262 at 3 to 6 days, 270 at 7 to 14 days, and 259 at 15 days or more. TEVAR performed at 15 days or more was independently associated with lower in-hospital/30-day mortality (odds ratio, 0.38; P = .0388) and improved 1-year survival. Postoperative stroke was associated with earlier repair (0-2 days). There was no association of timing of repair with spinal cord ischemia, retrograde type A dissection or reintervention.

CONCLUSIONS

TEVAR for TBAD with HRF delayed at least 15 days from symptom onset is associated with improved survival, supporting the theory that it is best to delay TEVAR until the subacute phase. Additionally, TEVAR delayed at least 3 days is associated with a decrease in stroke. Having more than one HRF was not associated statistically with worse outcomes. Because the classification of HRF is relatively new and without guidelines for repair, this study highlights the risks of early intervention for HRF and suggests that these patients seem to benefit from at least a short stabilization period before TEVAR.

Incidence of Distal Stent Graft Induced New Entry vs. Aortic Remodeling Associated With Frozen Elephant Trunk

Background

The introduction of the frozen elephant trunk (FET) technique for total arch replacement (TAR) has revolutionized the field of aortivascular surgery by allowing hybrid repair of complex aortic pathologies in a single step through combining an open surgical approach with an endovascular one. FET has been associated with favorable aortic remodeling, however, its is also associated with development of distal stent graft induced new entry (dSINE) tears postoperatively. The rate of aortic remodeling and the incidence of dSINE have been linked together, in addition, there seems to be a relationship between these two variables and FET insetion length as well as graft size.

Aims

The scope of this review is to highlight the rate of aortic remodeling as well the incidence of dSINE associated with different FET devices available commercially. This review also aimed to investigate the relationship between aortic remodeling, dSINE, FET insertion length and FET graft size.

Methods

We conducted a comprehensive literature search using multiple electronic databases including PubMed, Ovid, Scopus and Embase in order to collate all research evidence on the above mentioned variables.

Results

Thoraflex™ Hybrid Plexus seems to yield optimum aortic remodeling by promoting maximum false thrombosis as well true lumen expansion. Thoraflex Hybrid™ is also associated with the lowest incidence of dSINE post-FET relative to the other FET devices on the market. Aortic remodeling and dSINE do influence each other and are both linked with FET graft length and size.

Conclusion

The FET technique for TAR shows excellent aortic remodeling but is associated with a considerable risk of dSINE development. However, Thoraflex™ Hybrid has demonstrated itself to be the superior FET device on the aortic arch prostheses market. Since aortic remodeling, dSINE, FET insertion length and stent graft size are all interconnect, the choice of FET device length and size must be made with great care for optimum results.

Aortic Visceral Segment Instability is evident following Thoracic Endovascular Aortic Repair for Acute and Subacute Type B Aortic Dissection

BACKGROUND

Anatomic remodeling within the thoracic aorta following thoracic endovascular aortic repair (TEVAR) for type B aortic dissections (TBAD) has been well documented, but less is known about the response of the untreated visceral aorta. This study aims to investigate visceral aortic behavior following TEVAR for acute or subacute TBAD and identify associations with clinical outcomes.

METHODS

A multi-center retrospective review was performed of all imaging for all patients treated with TEVAR for acute (0-14 days) and subacute (14-90 days) non-traumatic TBAD between 2006-2020. Cohort was inclusive of uncomplicated, high-risk, and complicated (defined per SVS reporting guidelines) dissections. Centerline aortic measurements of the true and false lumen and total aortic diameter (TAD) were taken at standardized locations relative to aortic anatomy within each aortic zone (zones defined by SVS reporting guidelines). Diameter changes over time were evaluated using repeated measures mixed effects linear growth modeling. Visceral segment instability (VSI) was defined as any growth in TAD ≥ 5mm within aortic zones 5 through 9.

RESULTS

A total of 82 patients were identified. Median length of imaging follow-up was 2.1 years (IQR 3.9 years), with 15% of the cohort having follow-up longer than 5 years. VSI was present in 55% of the cohort, with an average maximal increase in TAD of 10.4±6.3 mm over a median follow-up of 2.1 years (IQR 3.9 years). Roughly a third of the cohort experienced rapid VSI (growth ≥5mm in first year), and 4.8% of the cohort developed a large para-visceral aneurysm aortic (TAD≥5cm) secondary to VSI. Linear growth modeling identified significant predictable growth in TAD across all visceral zones. Zones 7 had the highest rate of TAD dilation, with a fixed effect estimated rate of 1.3 mm per year (95%-CI 0.23-2.1, p=0.022). The preoperative factor most strongly associated with VSI was ≥6 cumulative number of zones dissected (OR 6.4, 95% OR 1.07-8.6, p=0.041). Odds for aortic reintervention were significantly increased in cases where VSI led to development of a para-visceral aortic aneurysm ≥5cm development (OR 3.7, 95%-CI 1.1-13, p=0.038).

CONCLUSION

VSI was identified in the majority of patients treated with TEVAR for management of acute and subacute TBAD. Preoperative anatomic features such as extent of dissection, rather than procedural details of graft coverage, may play a more significant role in VSI occurrence. Importantly, significant TAD growth occurred in all visceral segments. These results highlight the importance of lifelong surveillance following TEVAR, and identify a subset of patients that may be at increased risk for re-intervention.

Aortic remodeling after false lumen occlusion using an atrial septal occluder in chronic DeBakey IIIb aortic dissection

OBJECTIVE

Retrograde false lumen flow through distal entry tears poses a challenge in the treatment of chronic DeBakey IIIb aneurysms. In the present report, we have described the feasibility and outcomes of false lumen occlusion using an atrial septal occluder (ASO) in chronic DeBakey IIIb dissection associated with a descending aneurysm.

METHODS

All the patients who had undergone thoracic endovascular aortic repair for chronic DeBakey IIIb aortic dissection at our institution from January 2014 to November 2020 were retrospectively reviewed. The primary endpoints were technical success and in-hospital postoperative results. The secondary endpoints included the midterm survival status and aortic remodeling outcomes.

RESULTS

A total of 37 patients (age, 56.24 ± 10.47 years) with persistent retrograde false lumen perfusion and aneurysm formation at the thoracic segment were treated using an ASO for false lumen occlusion. We achieved 100% technical success. No spinal cord ischemia or in-hospital death was observed. The median follow-up time was 36 months (interquartile range, 24-51 months). After the procedure, three patients (8.1%) had had an endoleak (type Ia in two patients and type II in one patients), and five patients had required late reintervention. The overall 5-year survival rate was 71%. One aortic-related death (2.7% of the total cohort) occurred during follow-up at 9 months. Complete thrombosis of the false lumen along the treated aortic segment was recorded postoperatively in 34 patients (91.9%) at the final follow-up using computed tomography angiography. In a mixed-effects model, a diameter analysis revealed that the thoracic true lumen diameter had increased and the thoracic false lumen diameter had decreased significantly (0.256 mm/mo, P < .001; and -0.512 mm/mo, P < .001, respectively).

CONCLUSIONS

The combination of standard thoracic endovascular aortic repair and false lumen occlusion using the ASO to promote false lumen thrombosis and remodeling in the treated segments is a technically feasible and effective alternative treatment of chronic DeBakey IIIb dissection with an associated descending aneurysm. This approach yielded satisfactory midterm survival outcomes and a low incidence of aortic-related death in our patients. However, further studies with more subjects and a prospective design should verify our findings before routine clinical implementation of this technique.

The Distance From the Primary Intimal Tear to the Left Subclavian Artery Predicts Thoracic Aortic Enlargement After Thoracic Endovascular Aortic Repair of Type B Aortic Dissection: A Retrospective Cohort Study

PURPOSE

The purpose of this study was to evaluate the association between the distance from the primary intimal tear (PIT) to the left subclavian artery (LSA) (PIT-LSA distance) and the risk of aortic enlargement after thoracic endovascular aortic repair (TEVAR).

METHODS

This is a retrospective cohort study. A total of 228 patients were reviewed from the database of the Registry Of type B aortic dissection with the Utility of STent graft (ROBUST) study performed from January 1, 2011, to December 31, 2016. Of them, 196 patients were eligible for analysis. The PIT-LSA distance was defined as the length from the distal edge of the LSA orifice to the proximal edge of the PIT along the centerline of the true lumen. According to the border between zone 3 and zone 4 of the Ishimaru classification, patients were divided into group A (n = 117, PIT-LSA distance ≤ 2 cm) and group B (n = 79, PIT-LSA distance > 2 cm). Thoracic aortic enlargement (TAE) was defined as a thoracic aortic volume increase of ≥20%. Multivariate Cox regression was used to estimate the association between the PIT-LSA distance and risk of TAE after TEVAR.

RESULTS

The mean age was 52.3 ± 11.6 years, and 88.8% of patients were male. There were no significant differences between groups in demographic and baseline characteristics. The PIT-LSA distance was 1.1 cm (range, -1.6 to 2.0 cm) in group A, and 2.9 cm (range, 2.1-12.6 cm) in group B. TAE occurred in 27 patients in group A, and 6 in group B. The mean follow-up was 12.4 months (range, 0.10-83.1 months) in group A, and 12.63 months (range, 0.10-82.77 months) in group B. The cumulative 12- and 24-month rates of freedom from TAE were 79.0% and 71.3% in group A, versus 92.5% and 92.5% in group B, respectively. Multivariate Cox regression analysis revealed that the PIT-LSA distance was an independent predictor of TAE after TEVAR (adjusted hazard ratio, 0.66; 95% confidence interval, 0.48-0.90; p = 0.009).

CONCLUSION

Patients with a more proximal PIT location have a higher incidence of thoracic aortic enlargement after TEVAR. The location of the PIT in relation to the LSA can be used to identify patients who need closed surveillance after TEVAR or early preemptive intervention.

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.

Aortic septotomy to optimize landing zones during thoracic endovascular aortic repair for chronic type B aortic dissection

OBJECTIVE

The role of thoracic endovascular aortic repair for chronic type B aortic dissection remains controversial. Clinical outcomes of thoracic endovascular aortic repair with recently implemented aortic septotomy strategy were compared with stand-alone thoracic endovascular aortic repair.

METHODS

Between 2008 and 2020, 88 patients with chronic type B aortic dissection and degenerative aortic aneurysm underwent a thoracic endovascular aortic repair with or without adjunctive aortic septotomy, consisting of 36 (41%) with de novo chronic type B aortic dissection and 52 (59%) with residual chronic type B aortic dissection after type A aortic dissection repair.

RESULTS

Aortic septotomy was performed in 31 patients (35%) to optimize the proximal (3/31;10%) and distal (31/31;100%) landing zones. The aortic septotomy techniques comprised laser aortic septotomy in 16 patients (52%) and cheese wire septotomy in 15 patients (48%) with a 97% overall technical success rate. The median time interval between aortic dissection occurrence and thoracic endovascular aortic repair was 1.2 years. During follow-up, there were 12 (21%) sudden deaths and 17 (30%) combined aorta-related and sudden deaths in the nonaortic septotomy group, whereas there were no deaths in the septotomy group (P < .001). Patients without aortic septotomy required aortic reinterventions more frequently than those with aortic septotomy (30% vs 7%; P = .014), and 77% of these procedures were related to residual retrograde false lumen flow. Positive aortic remodeling was confirmed in 90% and 37% in the aortic septotomy and nonseptotomy groups, respectively (P < .001).

CONCLUSIONS

Stand-alone thoracic endovascular aortic repair outcomes without adjunctive procedures for chronic type B aortic dissection remain unfavorable. In contrast, landing zone optimization using aortic septotomy resulted in a remarkably higher positive aortic remodeling rate. Routine aortic septotomy strategy may positively affect long-term chronic type B aortic dissection survival and expand thoracic endovascular aortic repair candidacy.

Use of ASD closure device for the sealing of false lumen entry in the ascending aorta after dissection Type A surgical repair

We present a case of a persistent false lumen after ascending aorta replacement due to Stanford Type A dissection treated by endovascular means. The main entry tear was occluded with an atrial septal defect closure device, sealing the false lumen. A total of five additional stents were implanted to centralise and secure the flow in the true lumen. CT scan at 6-month follow-up showed excellent results with a decreased total aortic diameter and thrombosed false lumen.

Aortic remodeling and competitive flow after surgical treatment of aortic dissection

Aortic remodeling after dissection is poorly understood and remains a focus of current research. In the present report, we have described the cases of two patients with acute lower extremity ischemia related to malperfusion from aortic dissection treated with extra-anatomic axillobifemoral bypass. During long-term follow-up, aortic remodeling led to reinstitution of flow through the native aorta. This resulted in competitive flow, leading to complete thrombosis of the extra-anatomic conduits. These cases highlight the occurrence of spontaneous aortic recanalization and subsequent competitive flow, two vascular phenomena that are not well understood but can significantly affect patient outcomes.

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.

The provisional extension to induce complete attachment technique is associated with abdominal aortic remodeling and reduces aorta-related adverse events after aortic dissection

OBJECTIVE

This study evaluated the efficacy of the provisional extension to induce complete attachment (PETTICOAT) technique for type B and postoperative residual type B aortic dissections compared with the conventional thoracic endovascular aortic repair (TEVAR) technique.

METHODS

In this retrospective study, we compared sequential aortic morphologic changes in consecutive patients with type B and postoperative residual type B aortic dissections treated with the PETTICOAT technique between January 2016 and December 2017 with patients treated with the conventional TEVAR between January 2013 and December 2015. Outcomes included aortic remodeling and aorta-related adverse events for 2 years postoperatively.

RESULTS

Forty-eight patients were included in this study (24 in the PETTICOAT group, 24 patients in the conventional TEVAR group). Although both groups showed aortic remodeling in the descending thoracic aorta, the PETTICOAT group developed significantly better aortic remodeling in the abdominal aorta compared with the conventional TEVAR group during the observation period. The PETTICOAT group had significantly fewer aorta-related adverse events compared with the conventional TEVAR group (8% vs 54%; P < .001). Aorta-related adverse events more commonly occurred in the poor remodeling group compared with in the good remodeling group (P = .001; hazard ratio, 8.32; 95% confidence interval, 2.26-30.64).

CONCLUSIONS

This study suggests that the PETTICOAT technique for aortic dissection may promote aortic remodeling and decrease the incidence of aorta-related adverse events. Additional studies are required to confirm these preliminary findings.

Full PETTICOAT in acute type B aortic dissection with patent false lumen may offer positive remodeling for the distal aorta

OBJECTIVE

The provisional extension to induce complete attachment (PETTICOAT) technique is a unique thoracic endovascular aortic repair (TEVAR) for aortic dissection, which consists of proximal descending aortic endografting plus distal bare-metal stenting. This study aimed to investigate the efficacy of the PETTICOAT technique in patients with acute-sub-acute complicated type B aortic dissections. In particular, we compared the remodeling effect of full PETTICOAT covering down to the abdominal aorta with that of simple entry closure.

METHODS

In this retrospective pre-post study, we compared the clinical course of consecutive patients undergoing TEVAR with the PETTICOAT technique in which proximal entry tear was excluded with a covered stent, and extension bare stents were placed down to the abdominal segment for acute-sub-acute complicated type B aortic dissections, between 2015 and 2017, with a control group treated with TEVAR with entry closure between 2011 and 2015. Outcomes included the aortic remodeling rate and the aortic diameter up to 1 year after surgery.

RESULTS

Subjects consisted of 47 patients (21 in full PETTICOAT group, 26 in the simple entry closure group). The remodeling rate of the abdominal aorta in the full PETTICOAT group was significantly higher than in the simple entry closure group (p < 0.05), while that of the thoracic aorta was comparable between the two groups.

CONCLUSIONS

This study suggests that the full PETTICOAT technique achieves better aortic remodeling compared to entry closure alone, and might lead to less reintervention.

The Number of Preoperative Abdominal False Lumen-perfused Small Branches Is Related to Abdominal Aortic Remodeling after Thoracic Endovascular Aortic Repair for Type B Aortic Dissection

BACKGROUND

Abdominal aortic enlargement (AAE) is a commonly seen complication after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD). This study assessed the relationship between preoperative abdominal false lumen-perfused small branches (pre-AFLSBs) and risk of AAE after TEVAR for TBAD extending through the abdominal aorta.

METHODS

One hundred and eighty-four patients with TBAD who had been treated by TEVAR at 4 hospitals in China were stratified in accordance with median pre-AFLSBs: ≤8 (group A) and >8 (group B). AAE was defined as ≥20% increase in abdominal total aortic volume, measured using imaging software featuring centerline analysis, on most recent postoperative computed tomography angiography relative to preoperative examination. Multivariable Cox proportional hazard regression was used to evaluate the relationship between the number of pre-AFLSBs and the risk of AAE after TEVAR.

RESULTS

At median 12.4 months imaging follow-up, AAE was present in 65 patients at higher cumulative rate (log-rank test P < 0.001) in group B, which had more frequent partially thrombosed or patent abdominal false lumen than group A at 6-12 months (P < 0.01) and 12-24 months (P = 0.03) of follow-up. In a multivariable Cox proportional hazard regression model, the number of pre-AFLSBs was independently associated with risk of AAE after TEVAR (hazard ratio [for one increase], 1.10; 95% confidence interval, 1.00-1.21; P = 0.04) after adjustment for age, gender, dissection chronicity, Society for Vascular Surgery risk score, preoperative maximum descending aortic diameter, false lumen status of the abdominal aorta, numbers of false lumen-perfused visceral arteries, abdominal intimal larger tears, and preoperative abdominal intimal small tears, and dissection length and descending aortic length ratio.

CONCLUSIONS

The number of pre-AFLSBs was positively associated with the risk of AAE after TEVAR for TBAD extending through the abdominal aorta.

Laser aortic septotomy during thoracic endovascular aortic repair for chronic type B aortic dissection

OBJECTIVE

Persistent false lumen perfusion due to the presence of a thick aortic septum is a significant obstacle to successful thoracic endovascular aortic repair for chronic type B aortic dissection (cTBAD). We describe our new approach of laser aortic septotomy to optimize the landing zone.

METHODS

Between 2019 and 2020, 11 patients with cTBAD with degenerative aneurysm underwent laser aortic septotomy during thoracic endovascular aortic repair. A prospectively maintained database was retrospectively reviewed.

RESULTS

The median age was 70.0 years, and 10 (91%) were men. Six (55%) were de novo type B aortic dissection and 5 (45%) were residual type B aortic dissection. The age of aortic dissection was 2.9 years (interquartile range, 1.1-12.1). Technical success was achieved in 91% (10/11). In 1 case (9%), laser aortic septotomy was not feasible due to extremely tortuous aorta. Among successful cases, the median extents of proximal and distal laser fenestrations were Th7.5 and Th11.0, respectively and distal landing zones included zone 4 (40%) and zone 5 (60%). Two (18%) underwent a continuous longitudinal laser fenestration, and 8 (73%) had longitudinal spot laser fenestrations with immediate balloon dilatations. Apposition of the stent-graft to the outer aortic wall of the newly created common aortic lumen with elimination of retrograde false lumen flow was achieved in all cases.

CONCLUSIONS

This is the first description using the laser technology to optimize the distal landing zone for cTBAD. This new technique is safe and reproducible, with excellent controllability to achieve aortic septotomy at the desired target aorta segment.

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.

Management of the Left Subclavian Artery in TEVAR for Chronic Type B Aortic Dissection

Objectives:

Left subclavian artery (LSA) revascularization in thoracic endovascular aortic repair (TEVAR) remains controversial. Left subclavian artery coverage without revascularization can cause stroke and death. TEVAR has gained popularity for the treatment of chronic type B aortic dissection (cTBD). Using the Vascular Quality Initiative (VQI) database, we reviewed outcomes of LSA revascularization in TEVAR for cTBD.

Methods:

The VQI registry identified 5683 patients treated with TEVAR from July 2010 to July 2016, including 208 repairs for cTBD. We analyzed outcomes per the Society for Vascular Surgery reporting standards.

Results:

Of the 208 patients, 150 (72.1%) were male with a median age of 65.0 years (interquartile range [IQR], 55.0-72.0). Median aneurysm diameter was 5.7 cm (IQR, 5.0-6.5 cm). Data on the patency of the LSA was available in 131 (63.0%) patients. Twenty-five (19.1%) had occlusion of the LSA without revascularization, while 106 (80.9%) maintained patency or had revascularization. Successful device delivery occurred in all 131 (100%) patients. Maintaining LSA patency did not affect the rate of cerebrovascular accident ( P = .16), spinal cord ischemia ( P = 1.00), or death ( P = 1.00). This was also nonsignificant when analyzing the subgroup of 98 elective cases. There was no difference in the rates of endoleak. Any intervention for the LSA (revascularization or occlusion) led to a longer procedure time (203.6 minutes vs 163.7 minutes, P = .04).

Conclusions:

Maintaining LSA patency during TEVAR for cTBD offers no advantage in perioperative morbidity or endoleak. Occlusion of LSA may be performed safely in this cohort and revascularization reserved for those who have anatomy that compromises perfusion to critical organs.

Thoracic aortic remodeling with endografting after a decade of thoracic endovascular aortic repair experience

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) results have been studied in short-term time frames. This study aimed to evaluate midterm and long-term outcomes of TEVAR, emphasizing postoperative aortic remodeling and need for reintervention.

METHODS

This is an institutional retrospective review of TEVAR for isolated descending thoracic aortic aneurysms. Data were collected from 2004 to 2018. Primary outcomes studied included aneurysm sac remodeling, freedom from reintervention, and all-cause mortality. Other outcomes studied include endoleak rates, neurologic complication rates, and any overall postoperative complication rates.

RESULTS

During the study period, 219 patients underwent TEVAR for descending thoracic aortic aneurysms. The median effect of TEVAR on sac diameter was a 0.7-cm decrease in size (interquartile range, -1.4 to 0.0 cm). During the study period, 80% (n = 147) of patients experienced aneurysm sac regression or stability. Perioperative neurologic complications occurred in 16% (n = 34) of patients. Significant predictors of sac growth were endoleak (odds ratio [OR], 65; P < .001), preoperative carotid-subclavian bypass (OR, 8; P = .003), and graft oversizing <20% (OR, 15; P = .046). Every 1-mm increase in aortic diameter at the proximal TEVAR landing zone led to an increased odds of endoleak (OR, 2; P = .049). Access complications (OR, 8) and subclavian artery coverage (OR, 6) significantly increased the odds of reintervention, whereas every percentage of graft oversizing protected against reintervention (OR, 0.005). Life-table analysis revealed an overall survival of 78% (71%-83%) at median follow-up. At 3 years, survival was 88% (80%-93%) for those with aneurysm sac stability or regression, whereas it was 70% (49%-84%) for those with aneurysm sac growth (P = .0402). Cox proportional hazards model showed that the only protective factor for mortality was percentage oversizing, with every 1% of oversizing having a hazard ratio (HR) of <.001 (P = .032). This was counterbalanced by the fact that patients with graft oversizing >30% had an increased odds of mortality with HR >10 (P = .049). Other significant factors that increased the odds of mortality included endoleak (HR, 3.6; P = .033), diabetes (HR, 4.1; P = .048), age (every 1-year increase in age; HR, 1.2; P = .002), year of surgery (every year subsequent to 2004; HR, 1.3; P = .012), and peripheral artery disease (HR, 5.2; P = .041).

CONCLUSIONS

The majority of patients (80%) experience sac stability or regression after TEVAR, which offers a clear survival advantage. Endoleaks are predictive of sac growth, conferring increased mortality. Rigorous surveillance is necessary to prevent future aortic events through reintervention.

The 301 Classification: A Proposed Modification to the Stanford Type B Aortic Dissection Classification for Thoracic Endovascular Aortic Repair Prognostication

OBJECTIVE

To assess the usefulness of a modified Stanford classification for risk stratification of complications after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD).

PATIENTS AND METHODS

This retrospective analysis included 201 patients from an observational multicenter cohort study who underwent TEVAR for TBAD from January 1, 2011, to December 31, 2016. The patients were divided by using a modified Stanford classification, termed 301, into 3 groups: types B1 (n=62) and B3 (n=24), with a true and false lumen, respectively, descending closely along the thoracic vertebral bodies, and type B2 (n=115), a semi-spiral or spiral configuration. The value of the 301 classification in assessing the risk for post-TEVAR thoracic aortic expansion, as main outcome, and other complications was assessed by using the Kaplan-Meier method and multivariable Cox proportional hazards models.

RESULTS

Median follow-up duration was 26.37 months, and the 24-month cumulative rate of freedom from thoracic aortic enlargement was 0.58 (95% CI, 0.25 to 0.81) for type B3, 0.75 (95% CI, 0.64 to 0.83) for type B2, and 0.97 (95% CI, 0.88 to 0.99) for type B1. In the multivariable Cox regression models, types B2 and B3 with type B1 as reference were independently associated with the risk for thoracic aortic expansion (type B2: hazard ratio, 7.81; 95% CI, 1.84 to 33.13; type B3: hazard ratio, 13.91; 95% CI, 2.86 to 67.69).

CONCLUSION

The 301 classification, a modified Stanford classification system in the era of endovascular repair, appears to improve the risk stratification of patients with TBAD undergoing TEVAR.

TRIAL REGISTRATION

Chinese Clinical Trial Registry number: ChiCTR-POC-17011726.

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

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

Placement of a Zenith® Dissection Endovascular System in the Descending Thoracic Aorta Can Hamper Further Surgical Aortic Operations

Introduction

The efficacy of endovascular treatment for complicated Stanford type B acute aortic dissection is being established. However, aortic events sometimes occur, and some cases require surgical intervention.

Report

A 52 year old man underwent ascending aorta replacement for Stanford type A acute aortic dissection in August 2016. Post-operative computed tomography (CT) showed residual dissection from the aortic arch to the right common iliac artery and a large re-entry in the right common iliac artery (RCIA). Two months after the operation, CT revealed enlargement of the false lumen of the thoracic aorta and the thoracic aortic diameter. Aiming to reduce the false lumen and remodel the aorta, a three stage operation was performed, as described below. Four months after the dissection, total aortic arch replacement and a frozen elephant trunk insertion were performed as the first stage. Subsequently, as a second stage operation, thoracic endovascular repair (TEVAR) was performed using a Zenith® Dissection Endovascular System (Cook Japan Co., Ltd, Tokyo, Japan), with the aim of expanding the true aortic lumen. The implanted devices were a stent graft for the proximal part and two bare stents for the middle and distal part. As a third stage operation, abdominal aortic endovascular treatment was performed with the purpose of closing the re-entry from the RCIA. However, two years after the three stage operation, CT showed that the thoracic aorta was over 60 mm in diameter. Graft replacement of the thoraco-abdominal aorta was performed. The bare stents were expected to be easily removable from the aorta, but unexpectedly, they were strongly attached to the intima, which made it extremely difficult to perform surgical and aortic operations.

Discussion

Surgical operations for the aorta can become more difficult after bare stent placement in the aorta.

•

Surgical operations on the aorta can be hampered after intra-aortic bare stent placement.

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The bare stents and the intima of the true lumen were integrated.

•

Operability seemed to be relatively smooth when the electric cautery was operated at a high output.

False lumen embolization as a rescue technique in the setting of acute and chronic dissecting aneurysms as adjunct to thoracic endovascular aortic repair

Complicated type B aortic dissection (TBAD) is a life-threatening condition requiring surgical intervention. One such complication in the acute or chronic setting is aneurysmal degeneration. The dissected aortic wall is weakened, and the pressures in the false lumen are often high. In the past decade, thoracic endovascular aortic repair (TEVAR) has become the treatment of choice for TBAD. TEVAR can be complicated by lack of false lumen thrombosis, increasing the risk of death. We present three cases of TBAD with patent false lumens after TEVAR that were treated by false lumen coil embolization.

Thoracic Endovascular Aortic Repair for Type B Aortic Dissection Associated with Retrograde Type A Intramural Hematoma

PURPOSE

To evaluate feasibility and efficacy of thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) associated with retrograde type A intramural hematoma (IMH).

MATERIALS AND METHODS

From April 2013 to January 2017, 15 consecutive patients with TBAD associated with retrograde type A IMH who underwent TEVAR were reviewed retrospectively. There was no cardiac tamponade, aortic regurgitation, involvement of coronary artery, or sign of cerebral ischemia in these patients. Enhanced CT was used in 4 patients to diagnose malperfusion of abdominal visceral arteries or lower extremity artery and underwent emergent TEVAR. For the remaining 11 patients, repeated enhanced CT after initial medical treatment within 24 hours from onset of pain showed expansion of IMH in 8 patients or presence of periaortic hematoma in 3 patients. Delayed TEVAR was scheduled for these cases.

RESULTS

Successful deployment of the stent graft was achieved in all patients. There were no severe postoperative complications, such as retrograde type A aortic dissection or aortic rupture. Sudden death occurred in 1 patient 3 months after the procedure. Thrombosis of the false lumen, shrinkage of the diameter of the aorta, and complete absorption of the IMH were observed in the remaining patients at a mean follow-up of 19.8 months ± 6.57.

CONCLUSIONS

TEVAR for treatment of TBAD with retrograde type A IMH is feasible and effective. It represents a treatment option for patients with TBAD associated with type A IMH with a proximal entry tear located in the descending aorta.

Association Between Extent of Stent-Graft Coverage and Thoracic Aortic Remodeling After Endovascular Repair of Type B Aortic Dissection

Purpose: To examine the association between the extent of stent-graft coverage and thoracic aortic expansion after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection. Materials and Methods: A retrospective analysis was conducted of 201 patients (mean age 52.4±11.5 years; 178 men) with acute (135, 67.2%) or chronic (66, 32.8%) type B aortic dissection who underwent TEVAR at 4 medical centers. The mean stent-graft length was 157.1±33.3 mm. The percentage of stented descending aorta (PSDA) represented the extent of stent-graft coverage. After using restricted cubic smoothing spline plots to confirm the roughly linear relationship between PSDA and the risk of thoracic aortic expansion, patients were stratified into 2 groups on the median PSDA: the lower group (≤31.3%) and the higher group (>31.3%). Thoracic aortic expansion was defined as a ≥20% increase in the total thoracic aortic volume on the most recent postoperative computed tomography angiography scan compared with the preoperative measurement. The Kaplan-Meier method was used to estimate the cumulative freedom from thoracic aortic expansion after TEVAR; estimates are given with the 95% confidence interval (CI). A multivariable Cox proportional hazards model was used to analyze any independent association of the PSDA as a continuous or categorical variable with the risk of thoracic aortic expansion; results are presented as the hazard ratio (HR) and 95% CI. Results: No patients developed symptoms of spinal cord ischemia during hospitalization. Over a median 12.4 months of imaging follow-up, 34 (16.9%) patients developed thoracic aortic expansion. The estimate of freedom from thoracic aortic expansion at 12 months for the overall PSDA was 84.0% (95% CI 77.8% to 88.6%); between the groups, the freedom from thoracic aortic expansion estimate for the PSDA ≤31.3% group was significantly lower than in the higher group (p=0.032). Regression analysis showed no significant association between the risk of thoracic aortic expansion and the PSDA as a continuous variable (HR 0.97, 95% CI 0.91 to 1.03, p=0.288); however, analyzing the PSDA as a categorical variable indicated a significantly lower risk of thoracic aortic expansion for the PSDA >31.3% group (HR 0.46, 95% CI 0.22 to 0.95, p=0.036) after adjusting for a variety of demographic and anatomical characteristics. Conclusion: More extensive stent-graft coverage appears to improve thoracic aortic remodeling after TEVAR. However, the clinician should balance the benefit of extensive stent-graft coverage and its related risk of spinal cord ischemia.

Superior mesenteric artery branch pseudoaneurysm rupture mimicking acute pancreatitis in a patient with acute type B aortic dissection: A case report

RATIONALE

Visceral arterial pseudoaneurysms are rare but important vascular entities because of their inclination to cause life-threatening hemorrhage. They were commonly reported to be associated with trauma, infection, inflammatory disease, or occurred as postoperative complication. To date, there has been no published report of a superior mesenteric artery (SMA) branch pseudoaneurysm rupture mimicking acute pancreatitis in a patient with acute type B aortic dissection.

PATIENT CONCERNS

The patient's medical history, clinical information, imaging findings including follow-up computed tomography angiography (CTA), and treatment are reported. A 51-year-old male presenting with epigastric pain and fever was found to have an enlarged pancreatic head and obscure fatty space around it on abdominal nonenhanced CT. He has medical history of anaphylactoid purpura and uncontrolled hypertension. His serum lipase and amylase were both within normal limits. Thoracoabdominal CTA following a sudden blood pressure drop attributed to the accurate diagnosis.

DIAGNOSES

He was diagnosed with acute type B aortic dissection involving SMA and retroperitoneal hemorrhage secondary to SMA branch pseudoaneurysm rupture.

INTERVENTIONS

The patient was successfully treated by thoracic endovascular aortic repair without additional branch intervention.

OUTCOMES

Follow-up CTA at 3 months later demonstrated that the endoprothesis is well positioned with no endoleaks, and SMA branch pseudoaneurysm disappeared.

LESSONS

We report a rare and complicated case presenting with SMA branch pseudoaneurysm rupture and acute type B aortic dissection. CTA is vital in the diagnosis of such vessel pathology. We must inspect carefully to ensure that no small lesions are missed.

Type 2 diabetes mellitus reduces clinical complications and mortality in Stanford type B aortic dissection after thoracic endovascular aortic repair: A 3-year follow-up study

BACKGROUND

Previous studies have demonstrated that type 2 diabetes mellitus (T2DM) is negatively correlated with the occurrence of aortic dissection (AD). This study aimed to investigate the effects of T2DM on the prognosis of Stanford type B AD (STBAD) patients after thoracic endovascular aortic repair (TEVAR).

METHODS

STBAD patients (n = 141) who underwent TEVAR received an oral glucose tolerance test (OGTT) and were divided into a normal glucose (NG, n = 55) group, an abnormal glucose tolerance (AGT, n = 48) group and a T2DM (n = 38) group according to the results of the OGTT. Data on mortality, clinical complications, left ventricular (LV) remodeling and aortic remodeling were collected during the 3-year follow-up.

RESULTS

Lower mortality and fewer clinical complications after TEVAR were found in the T2DM group than in the NG group. Multivariate linear regression analysis showed that 2-hour postprandial glucose (Glu-2h) was negatively correlated with mortality and the occurrence of clinical complications in STBAD patients after TEVAR. In addition, better LV remodeling, larger true lumen areas and smaller false lumen areas in both the proximal aortas and abdominal aortas were observed in the T2DM group than in the NG group. Furthermore, no significant differences in mortality or clinical complications after TEVAR were found between the NG group and the AGT group or between the T2DM group and the AGT group.

CONCLUSION

During the 3-year follow-up period, mortality and clinical complications in STBAD patients after TEVAR were significantly reduced in the T2DM group. For STBAD patients who undergo TEVAR, properly relaxing of blood glucose control requirements may be beneficial for their prognosis.

Implications of secondary aortic intervention after thoracic endovascular aortic repair for acute and chronic type B dissection

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) has become a mainstay of therapy for acute and chronic type B aortic dissection (TBAD). Dynamic aortic morphologic changes, untreated dissected aorta, and persistent false lumen perfusion have significant consequences for reintervention after TEVAR for TBAD. However, few reports contrast differences in secondary aortic intervention (SAI) after TEVAR for TBAD or describe their influence on mortality. This analysis examined incidence, timing, and types of SAI after TEVAR for acute and chronic TBAD and determined their impact on survival.

METHODS

All TEVAR procedures for acute and chronic TBAD (2005-2016) were retrospectively reviewed. Patients with staged (<30 days) or concomitant ascending aortic arch repair or replacement were excluded. Acuity was defined by symptom onset (0-30 days, acute; >30 days, chronic). SAI procedures were grouped into open (intended treatment zone or remote aortic site), major endovascular (TEVAR extension or endograft implanted at noncontiguous site), and minor endovascular (side branch or false lumen embolization) categories. Kaplan-Meier methodology was used to estimate freedom from SAI and survival. Cox proportional hazards were used to identify SAI predictors.

RESULTS

TEVAR for TBAD was performed in 258 patients (acute, 49% [n = 128]; chronic, 51% [n = 130]). Mean follow-up was 17 ± 22 months with an overall SAI rate of 27% (n = 70; acute, 22% [28]; chronic, 32% [42]; odds ratio, 1.7; 95% confidence interval, 0.9-2.9; P = .07]. Median time to SAI was significantly less after acute than after chronic dissection (0.7 [0-12] vs 7 [0-91] months; P < .001); however, freedom from SAI was not different (1-year: acute, 67% ± 4%, vs chronic, 68% ± 5%; 3-year: acute, 65% ± 7%, vs chronic, 52% ± 8%; P = .7). Types of SAI were similar (acute vs chronic: open, 61% vs 55% [P = .6]; major endovascular, 36% vs 38% [P = .8]; minor endovascular, 21% vs 21% [P = 1]). The open conversion rate (either partial or total endograft explantation: acute, 10% [13/128]; chronic, 15% [20/130]; P = .2) and incidence of retrograde dissection (acute, 6% [7/128]; chronic, 4% [5/130]; P = .5) were similar. There was no difference in survival for SAI patients (5-year: acute + SAI, 55% ± 9%, vs acute without SAI, 67% ± 8% [P = .3]; 5-year: chronic + SAI, 72% ± 6%, vs chronic without SAI, 72% ± 7% [P = .7]). Factors associated with SAI included younger age, acute dissection with larger maximal aortic diameter at presentation, Marfan syndrome, and use of arch vessel adjunctive procedures with the index TEVAR. Indication for the index TEVAR (aneurysm, malperfusion, rupture, and pain or hypertension) or remote preoperative history of proximal arch procedure was not predictive of SAI.

CONCLUSIONS

SAI after TEVAR for TBAD is common. Acute TBAD has a higher proportion of early SAI; however, chronic TBAD appears to have ongoing risk of remediation after the first postoperative year. SAI types are similar between groups, and the occurrence of aorta-related reintervention does not affect survival. Patients' features and anatomy predict need for SAI. These data should be taken into consideration for selection of patients, device design, and surveillance strategies after TEVAR for TBAD.

Aortic remodelling after thoracic endovascular aortic repair for acute and subacute type B aortic dissection

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) in the current era has gained widespread acceptance as the modality of choice for the treatment of complicated aortic dissection (AD). However, reports on clinical results of TEVAR treatment of AD patients are mainly comparisons and analyses of results between patients in the acute and chronic phases, few reports have described the postoperative aortic remodelling of patients with subacute AD after TEVAR. The aim of this study was to investigate aortic remodelling after TEVAR in acute and subacute Stanford type B AD patients.

METHODS

The clinical data of 38 Stanford type B AD patients who received TEVAR treatment in our hospital between July 2012 and December 2017 were retrospectively analysed. The maximum diameters of the aorta, the mean diameters of the true lumens (TLs) and the false lumens (FLs) of the aorta in the dissection range before and after TEVAR treatment were measured. All diameters between different groups or in the same group before and after therapy were compared using nonparametric tests. Count data were examined using the χ² test.

RESULTS

The 38 patients were 31.0-82.0 years old with a mean age of 57.0±11.0 years, including 31 men and 7 women, with 22 patients in the acute phase and 16 patients in the subacute phase. Among the 38 patients included in this study, 7 (18.4%) patients had endoleaks after treatment. No perioperative deaths occurred. Analyses of computed tomography angiography measurement results showed that the baseline maximum diameters of the aorta, TLs and FLs before TEVAR between the acute and subacute groups were not significantly different (P=0.193, P=0.301 and P=0.067, respectively). After TEVAR treatment, the maximum diameters of the aorta and the diameters of the FLs were different between the two groups (P=0.005 and P=0.012), but the diameters of the TLs were not (P=0.069). The diameters of the TLs increased, and those of FLs decreased significantly in the acute and subacute groups after TEVAR (P<0.001, P<0.001, P<0.001 and P=0.007, respectively); the maximum diameters of the aorta decreased significantly in the acute group (P<0.001), but they did not change obviously in the subacute group (P=0.121).

CONCLUSIONS

TEVAR offers satisfactory results for the treatment of type B AD. Acute AD may be associated with better aortic remodelling compared to subacute AD after TEVAR.

Protocol for the ROBUST (Registry Of type B aortic dissection with the Utility of STent graft) study: an ambispective, multicentre, open cohort study

INTRODUCTION

Thoracic endovascular aortic repair (TEVAR) is widely used for type B aortic dissection, although with satisfactory outcome in a limited proportion of patients. To better inform patient prognostication, the Registry Of type B aortic dissection with the Utility of STent graft (ROBUST) study aims to identify imaging-based predictors of post-TEVAR adverse outcomes up to 10-year follow-up.

METHODS AND ANALYSIS

ROBUST is designed as an ambispective, multicentre, open cohort study. All patients undergoing TEVAR from 1 January 2008 to 1 July 2027 at participating centres will be invited to join the study. It is conservatively estimated that over 2000 patients will join the study. Data on demographics, disease history, procedural details, imaging features and follow-up will be collected after discharge. Cox proportional-hazards analysis will be used to identify independent predictors of primary outcomes. Stratification analysis will be performed to identify which subgroup of patients would benefit the most from TEVAR.

ETHICS AND DISSEMINATION

The protocol has been approved by the ethics committee of the coordinating centre. Findings will be disseminated in professional peer-reviewed journals to promote understanding of the rehabilitation process.

TRIAL REGISTRATION NUMBER

ChiCTR-POC-17011726; Pre-results.

Endovascular entry closure using Amplatzer vascular plug for the aortic dissection in sub-acute phase

Enlargement due to residual dissection after surgical ascending aortic replacement is technically challenging to treat. Endovascular entry closure using an Amplatzer vascular plug 2 (AVP2) in the sub-acute phase has not been reported. A 75-year-old female underwent emergent ascending aorta replacement for Stanford type A aortic dissection. Postoperative computed tomography angiography (CTA) showed a distal aortic arch diameter of 41 mm and a patent false lumen. CTA one month after the operation revealed distal aortic arch enlargement to 52 mm, which is considered high-risk for rupture. Repeat open surgery was considered but carried a high risk of perioperative complications. Therefore, we performed endovascular closure for the entry at the proximal descending aorta using an AVP2 and stent graft coverage and coil embolization for the re-entries at the bilateral iliac arteries. CTA one month after the procedure revealed that the false lumen of the aortic arch was thrombosed and that the distal aortic arch had shrunk to 38 mm, indicating the efficacy of endovascular entry closure with the AVP2 after aortic dissection. <Learning objective: Endovascular entry closure for residual dissection more than 2 years after ascending aorta replacement has already been reported. We conducted this procedure in the sub-acute phase and induced favorable aortic remodeling. The endovascular entry closure was successfully conducted for a patient presenting residual tears after emergent ascending aorta replacement, considering a treatment option with high risk for repeat open surgery.>.

Early and midterm outcomes of thoracic endovascular aortic repair (TEVAR) for acute and chronic complicated type B aortic dissection

Thoracic endovascular aortic repair (TEVAR) in the current era has been chosen as a dominant and minimally invasive treatment for complicated aorta dissection. This study aimed to assess safety and feasibility of TEVAR in acute and chronic type B aortic dissection.Between January 2011 and December 2013, 85 patients with complicated type B aortic dissection undergoing TEVAR were divided into acute aortic dissection (AAD) (n = 60) group and chronic aortic dissection (CAD) group (n = 25). Computed tomography was used to evaluate postoperative changes in maximal aortic diameter and true and false lumen diameters at 3 levels during a mean follow-up period of 26.4 ± 15.6 months.The technical success rate was 100%. In-hospital and 30-day rates of death were 3.3% in acute group and 0 in chronic group. Postdischarge rates of type I leak, type II leak, and retrograde type A dissection were 6.7%, 5.2%, and 3.4% (acute) and 0%, 4.0%, and 4.0% (chronic), respectively. The maximal aorta diameter remained stable in all the 3 levels in both acute and chronic group. The cumulative freedom from all-cause mortality at 3 years was similar in acute and chronic groups (89.5% vs 95.5%, P = .308). The cumulative freedom from aortic-related mortality was also not significantly different in the acute and chronic groups (92.8% vs 95.2%, P = .531). In the thoracic aorta, TEVAR treatment resulted in a significant increase in true lumen (TL) diameter and decrease in false lumen (FL). However, in the abdominal aorta, TEVAR did not lead to significant change in TL and FL diameters. The rates of complete thrombosis thoracic false lumens were better than that in the abdominal false lumen.TEVAR was a safe and effect therapy for complicated acute and chronic type B dissection with low early and mid-term mortality and morbidity.

Influence of distal entry tears in acute type B aortic dissection after thoracic endovascular aortic repair

OBJECTIVE

This study evaluated the clinical influence of distal entry tears in acute type B aortic dissection (ATBAD) after thoracic endovascular aortic repair (TEVAR).

METHODS

From August 2009 to December 2014, the clinical outcomes of 130 patients who underwent TEVAR for ATBAD were retrospectively analyzed. According to whether distal entry tears existed after TEVAR, patients were divided into group A (n = 25, absence of distal entry tears) and group B (n = 105, presence of distal entry tears). We evaluated clinical outcomes, including mortality and morbidity in early and late follow-up, as well as aortic remolding. Late aortic events were defined as aortic dissection-related events occurring >30 days from the initial TEVAR procedures, which consisted of endoleak, retrograde type A aortic dissection, aortic enlargement, late rupture, repeat dissection, and stent-induced new entry tear.

RESULTS

The study comprised 130 patients (114 men [87.7%] and 16 women [12.3%)] with a mean age of 53.71 years. The 30-day mortality was 3.1%, and early morbidity included type I endoleak, 3.1%, organ failure, 3.8%; stroke, 3.1%; spinal cord ischemia, 0%; and early rupture 1.5%. The overall survival rate by Kaplan-Meier analysis at 1, 3, and 5 years was 93.8%, 89.5%, and 79.2%, respectively. There were no significant differences in early morbidity and 30-day mortality and late survival between group A and group B. However, group A had a significantly lower rate of late aortic events than group B (P = .028 by log-rank test). Meanwhile, group A had better aortic remolding than group B in complete thrombosis of the thoracic aorta at 12 months postoperatively (100% vs 83.5%; P = .029).

CONCLUSIONS

This study demonstrated that TEVAR for ATBAD had low perioperative morbidity and mortality and satisfactory midterm outcome. Distal entry tears increase the occurrence of late aortic events and inhibit aortic remolding but do not have a significantly negative effect on late survival. Repairing all entry tears to restore single-lumen blood flow and enhance false lumen thrombosis might benefit selected patients.