Aortic remodeling, volumetric analysis, and clinical outcomes of endoluminal exclusion of acute complicated type B thoracic aortic dissections

Favorable Remodeling After TEVAR in Uncomplicated Acute and Subacute Type B Aortic Dissection in Comparison to Conservative Treatment: A Midterm Analysis

PURPOSE

The purpose of the study was to evaluate the midterm and long-term outcomes of patients who underwent thoracic endovascular aortic repair (TEVAR) procedure to treat an uncomplicated acute and subacute type B aortic dissection (uATBAD) with high risk for subsequent aortic complications compared with the group of patients who received a conservative treatment protocol during the same period.

MATERIALS AND METHODS

Between 2008 and 2019, 35 patients who had TEVAR due to uATBAD and those with conservative procedure (n=18) were included in a retrospective analysis and follow-up study. The primary endpoints were false lumen thrombosis/perfusion, true lumen diameter, and aortic dilatation. The aortic-related mortality, reintervention, and long-term survival were the secondary endpoints.

RESULTS

In the study period, 53 patients (22 females) with a mean age of 61.1±13 years were included. No 30-day and in-hospital mortality was recorded. Permanent neurological deficits occurred in 2 patients (5.7%). In the TEVAR group (n=35) and in a median follow-up period of 34 months, a significant reduction of maximum aortic and false lumen diameter as well as a significant increase of true lumen diameter were detected (p<0.001 each). Complete false lumen thrombosis increased from 6% preoperatively to 60% at follow-up. The median difference in aortic, false lumen, and true lumen diameter was -5 mm (interquartile range [IQR]=-28 to 8 mm), -11 mm (IQR=-53 to 10 mm), and 7 mm (IQR=-13 to 17 mm), respectively. In 3 patients (8.6%), a reintervention was needed. Two patients (1 aortic-related) died during follow-up. The estimated survival according to Kaplan-Meyer analysis was 94.1% after 3 years and 87.5% after 5 years. Similar to the TEVAR group, no 30-day or in-hospital mortality was recorded in the conservative group. During follow-up, 2 patients died and 5 patients underwent conversion-TEVAR (28%). In a median follow-up period of 26 months (range=150), a significant increase of maximum aortic diameter (p=0.006) and a tendency to augmentation of the false lumen (p=0.06) were noted. No significant reduction of the true lumen was seen.

CONCLUSIONS

Thoracic endovascular aortic repair in patients at high risk of subsequent aortic complications in uncomplicated acute and subacute type B aortic dissection is safe and is associated with favorable midterm outcomes regarding aortic remodeling.

CLINICAL IMPACT

In a retrospective, single center analysis of prospectively collected data with follow-up, we compared 35 patients with high-risk features who recieved TEVAR in acute and sub-acute uncomplicated type B aortic dissection to a control-group (n=18). The TEVAR group showed a significant positive remoduling (reduction of max. aortic and false lumen diameter and increase of true lumen diameter (p<0.001 each)) during follow-up with an estimated survival of 94.1% after 3 years and 87.5% after 5 years.

Mid-term Outcomes of Thoracic Endovascular Aortic Repair (TEVAR) in Acute Complicated Type B Aortic Dissection: A Comprehensive Analysis of Aortic Remodeling Patterns

Purpose

This study provides a comprehensive analysis of the clinical outcomes associated with endovascular treatment for acute complicated type B aortic dissection, with a focus on the complex process of aortic remodeling.

Materials and Methods

We conducted a retrospective investigation using data extracted from the Songklanagarind Hospital database between January 2010 and January 2022. Electronic medical records of patients who underwent thoracic endovascular aortic repair (TEVAR) for acute complicated type B aortic dissections were reviewed. The analysis focused on in-hospital outcomes, overall survival, aorta-related survival, reintervention-free survival, and changes in aortic lumen diameter to assess aortic remodeling.

Results

Over the study period, 32 patients with acute complicated type B aortic dissections underwent TEVAR. The in-hospital mortality rate was 9.4%, with complications occurring in 21.9% of patients. Temporary acute kidney injury was observed in 9.4% of the cases, wound bleeding in 6.3%, pneumonia in 6.3%, and permanent spinal cord ischemia in 3.1%. Re-intervention was necessary in 6.3% of cases. The overall survival rates at 6 months, 1 year, 3 years, and 6 years were 78%, 75%, 65%, and 44%, respectively. Aorta-related survival rates were 87%, 87%, 83%, and 75% at the corresponding time intervals. The reintervention-free survival rates were 96%, 96%, 71%, and 71%, respectively. Survival analysis revealed that patients with ideal aortic remodeling experienced the most favorable outcomes, whereas those with undesirable aortic remodeling exhibited the least favorable survival. Notably, undesirable pattern of aortic remodeling emerged as a singular factor with a statistically significant influence on predicting survival (hazard ratio 4.37, P-value=0.021).

Conclusion

TEVAR resulted in favorable aorta-related survival outcomes. Notably, the identification of changes in aortic lumen diameter alongside false lumen thrombosis, encapsulated within the framework of aortic remodeling patterns, has emerged as a robust predictor of post-TEVAR survival outcomes.

Aortic Outcome after Implementation of a Treatment Strategy for Type B Aortic Dissection Involving the Aortic Arch

OBJECTIVE

To evaluate the outcomes achieved after implementing a treatment strategy for non-A non-B (NANB) (B 1-2 D according to the latest consensus document of the Society of Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS) acute aortic dissection (AAD)).

METHODS

This retrospective observational study adhered to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist. All cases of NANB AAD (B 1-2 D) treated at our institution between January 2016 and December 2022 were reviewed. Morbidity, mortality, aortic-related reintervention, and remodeling were analyzed.

RESULTS

Among 519 cases of acute aortic syndrome, n = 22 (4.2%) patients presented with NANB AAD (B 1-2 D) (n = 16,72.7% men, mean age 61.5 years+/14.7). Eleven cases were managed with best medical treatment (BMT) alone. Among them, one patient (9.1%) died suddenly 2 days after diagnosis for aortic rupture. Frozen elephant trunk procedure (FET) was required in the remaining 11 patients: 7 (31.8%) needed emergent operation for risks of impending aortic rupture or retrograde aortic dissection extension, and 4 (26.7%) underwent delayed surgery within a month from initial presentation. Overall, in-hospital mortality was 9.1% with both FET and BMT. At a median follow-up of 40 months (range 2 days-200 months) no other deaths occurred. A statistically significant differences in the rate of false lumen thrombosis (100% vs 55.5%, P = 0.033), and a significant positive aortic remodeling in zone 3 (P < 0.001) and 4 (P = 0.038) were reported in operated versus medically managed patients.

CONCLUSIONS

The best treatment for NANB is not established. We advocate for medical stabilization with an operative approach that favors open surgery in the acute post dissection period, promotes aortic remodeling, and carries acceptable risk in centers where FET is performed routinely.

Pre-emptive False Lumen Embolization to Prevent Persistent Type II Endoleak in Fenestrated-Branched Endovascular Repair of Post-Dissection Thoracoabdominal Aortic Aneurysms

PURPOSE

The purpose was to describe a technique to promote false lumen (FL) thrombosis in post-dissection thoracoabdominal aortic aneurysms (PD-TAAAs) managed by fenestrated/branched endografting (F/B-EVAR).

TECHNIQUE

A 5/6Fr-90 cm length sheath is advanced from the true lumen (TL) to FL through the most distal entry tear of the infrarenal aorta or iliac arteries. It is parked in the most cranial portion of the FL in the thoracic aorta. Aortic endografts are deployed in the TL excluding all the para-visceral/distal entry tears and target visceral vessels bridging stenting is performed. A selective FL angiography is performed through the 5/6Fr sheath to detect the origin of all segmentary arteries. Embolization of FL is performed from above to below by M-reye pushable coils, obtaining the packaging of FL. After completion angiography, the 5/6Fr sheath is retrieved in external iliac artery and molding ballooning of the distal segment of the aortic/iliac endograft is performed. Between 2019 and 2023, this technique was applied in 11cases with a median number of 73 (interquartile range [IQR=12) coils. Out of 8 (72%) patients with available radiological follow-up at 1 year, 7 exhibited complete FL thrombosis.

CONCLUSIONS

The FL coiling in PD-TAAAs managed by F/B-EVAR is feasible, safe, and effective to promote the complete FL thrombosis.

CLINICAL IMPACT

Preemptive false lumen embolization is a feasible, safe, and effective technique for preventing persistent type II endoleaks after fenestrated-branched endovascular repair of post-dissection thoracoabdominal aortic aneurysms. This technique may be routinely recommended to promote FL thrombosis and aortic remodeling after FB-EVAR in PD-TAAAs, thereby reducing the incidence of reinterventions during follow-up.

Aortic remodeling following hybrid arch repair with zone 0 to 5 thoracic endovascular aortic repairs for complex arch and descending thoracic aortic pathologies

Objective

For high-risk patients with aortic arch pathology, hybrid aortic arch repair with simultaneous or staged thoracic endovascular repair of the descending aorta may be a viable alternative to open repair. However, data on postintervention aortic remodeling remain limited. We report the short-term outcomes of remodeling of the thoracoabdominal aorta after hybrid arch repair + thoracic endovascular repair.

Methods

All patients undergoing hybrid arch repair with planned zones 0 to 5 thoracic endovascular repair from January 2020 to March 2022 were retrospectively reviewed. Computed tomography angiography scans preoperatively, after hybrid aortic arch repair, and on long-term follow-up were analyzed for thoracoabdominal aorta remodeling. Mean change in aortic true luminal diameter and full luminal diameter was calculated at every level, and paired-samples t test was used to compare means.

Results

Of 39 patients, 38 had follow-up data at a mean duration of 14.9 months. There were a total of 3 (7.7%) deaths, 0 (0.0%) strokes, and 0 (0.0%) paralysis. For the 35 patients undergoing thoracic endovascular repair for aortic dissection, at follow-up, there was a significant increase in the mean true luminal diameter at each level (P < .05), except at the aortic bifurcation and common iliac arteries. The largest increase in mean true luminal diameter (P < .01) was observed at the level of the left inferior pulmonary vein (mean difference +13.22 mm, 95% CI, 10.38-16.07), tracheal carina (mean difference +13.06 mm, 95% CI, 10.05-16.07), and inferior left atrium (mean difference +11.19 mm, 95% CI, 7.84-14.53).

Conclusions

Hybrid arch repair with zones 0 to 5 leads to improved true lumen augmentation in zones 0 to 8 with complete false lumen thrombosis down to zone 5 at short-term follow-up. Zones 9 to 11, if involved, may require adjunctive treatment strategies for total aortic remodeling and complete false lumen obliteration.

A systematic review and meta-analysis of retrograde type A aortic dissection after thoracic endovascular aortic repair in patients with type B aortic dissection

BACKGROUND

Retrograde type A dissection (RTAD) is a devastating complication of thoracic endovascular repair (TEVAR) with low incidence but high mortality. The objective of this study is to report the incidence, mortality, potential risk factors, clinical manifestation and diagnostic modalities, and medical and surgical treatments.

METHODS

A systematic review and single-arm and two-arm meta-analyses evaluated all published reports of RTAD post-TEVAR through January 2021. All study types were included, except study protocols and animal studies, without time restrictions. Outcomes of interest were procedural data (implanted stent-grafts type, and proximal stent-graft oversizing), the incidence of RTAD, associated mortality rate, clinical manifestations, diagnostic workouts and therapeutic management.

RESULTS

RTAD occurred in 285 out of 10,600 patients: an estimated RTAD incidence of 2.3% (95% CI: 1.9-2.8); incidence of early RTAD was approximately 1.8 times higher than late. Wilcoxon signed-rank testing showed that the proportion of RTAD patients with acute type B aortic dissection (TBAD) was significantly higher than those with chronic TBAD (P = .008). Pooled meta-analysis showed that the incidence of RTAD with proximal bare stent TEVAR was 2.1-fold higher than with non-bare stents: risk ratio was 1.55 (95% CI: 0.87-2.75; P = .13). Single arm meta-analysis estimated a mortality rate of 42.2% (95% CI: 32.5-51.8), with an I2 heterogeneity of 70.11% (P < .001).

CONCLUSION

RTAD is rare after TEVAR but with high mortality, especially in the first month post-TEVAR with acute TBAD patients at greater risk as well as those treated with proximal bare stent endografts.

Fate and Consequences of the False Lumen after TEVAR in Type B Aortic Dissection

BACKGROUND

Type B aortic dissection (TBAD) occurs due to an entry tear in the intimal layer of the aorta distal to the origin of the left subclavian artery where blood enters the newly formed false lumen (FL) and extends distally or proximally to form a dissection over an indeterminate length of the aorta which, over time, may eventually rupture. Thoracic endovascular aortic repair (TEVAR) aims to seal off the entry tear proximally with the stent-graft, occluding the origin of the dissection and excluding the FL. Nevertheless, in some cases, the perfusion to the FL is maintained, hindering the aortic remodelling process and increasing the risk of aneurysmal degeneration and rupture, particularly in the abdominal aorta where evidence suggest that remodelling is slower. This review examines the long-term effects of a patent or partially thrombosed FL on clinical outcomes following TEVAR in TBAD, also highlighting the pathological processes behind negative aortic remodelling. Another aim of this review is to provide an overview and appraisal of the currently available techniques for managing a patent or partially thrombosed FL to prevent long-term morbidity occurring.

METHODS

A comprehensive literature search was performed using several search engines including PubMed, Ovid, Google Scholar, Scopus, and Embase to identify and extract relevant studies.

RESULTS

Evidence in the literature show that a partially thrombosed FL is more dangerous than a patent FL due to the occlusion of the distal re-entry tears, impeding outflow and increasing mean arterial and diastolic pressures, whereas the latter is decompressed via distal re-entry sites. FL thrombosis and satisfactory remodelling is sometimes achieved in as few as 40% of patients after TEVAR due to the maintained perfusion of the FL either at the level of the thoracic or abdominal aorta. However, although the thoracic aorta is predominantly covered by the TEVAR stent-graft, poorer remodelling and more dilation is seen in the abdominal aorta. Several techniques are available to embolize the FL, including the Provisional Extension to Induce Complete Attachment, Stent Assisted Balloon Induced Intimal Disruption and Relamination in Aortic Dissection Repair, candy-plug, and Knickerbocker techniques.

CONCLUSIONS

The management of TBAD is invariably TEVAR to seal off the proximal entry tear while extending the repair distally to completely exclude the FL. A risk of aortic wall dilatation distal to TEVAR stent-graft remains; hence, regular monitoring and accurate imaging are essential. At present, a patent FL can be treated using a range of different endovascular techniques.

Volumetric Measurements Improve the Accuracy of Aortic Remodeling Prediction in Aortic Dissection

Accessing aortic remodeling status through regular follow-ups is essential for acute type A aortic dissection patients undergone surgical treatment. Aortic remodeling status was usually determined using diameter or area measurements of the true and false lumen in specific anatomical slices of medical images. However, these indicators only represent partial information about the aorta and can hardly characterize the overall aorta situation. In this study, we included two types of morphology features collected from computed tomography angiography images to predict the aortic remodeling. One type is the volumetric measurements of the true and false lumen, which provide a better overall description of the aorta, and the other type is the volumetric measurements of the thrombus in false lumen and the patent false lumen, which present more detailed information of the dissection. Through progressively incorporating these measurements into the construction of the remodeling prediction model, we investigated the importance of the features that describe the overall situation and that characterize aortic internal details in remodeling prediction, especially the effect of quantitative thrombosis features. The results showed that with the inclusion of the two types of volume features, the prediction accuracy of the model increased, which proves that volumetric measurements of aortic dissection, especially the volume of thrombus, are of significant value in aortic remodeling prediction, and should be paid more attention on in clinical practice and research areas. Clinical Relevance-Demonstrating the importance of volumetric measurements of true and false lumen thrombus in false lumen and patent false lumen in the prediction of aortic remodeling.

Imaging and Surveillance of Chronic Aortic Dissection: A Scientific Statement From the American Heart Association

All patients surviving an acute aortic dissection require continued lifelong surveillance of their diseased aorta. Late complications, driven predominantly by chronic false lumen degeneration and aneurysm formation, often require surgical, endovascular, or hybrid interventions to treat or prevent aortic rupture. Imaging plays a central role in the medical decision-making of patients with chronic aortic dissection. Accurate aortic diameter measurements and rigorous, systematic documentation of diameter changes over time with different imaging equipment and modalities pose a range of practical challenges in these complex patients. Currently, no guidelines or recommendations for imaging surveillance in patients with chronic aortic dissection exist. In this document, we present state-of-the-art imaging and measurement techniques for patients with chronic aortic dissection and clarify the need for standardized measurements and reporting for lifelong surveillance. We also examine the emerging role of imaging and computer simulations to predict aortic false lumen degeneration, remodeling, and biomechanical failure from morphological and hemodynamic features. These insights may improve risk stratification, individualize contemporary treatment options, and potentially aid in the conception of novel treatment strategies in the future.

Endovascular repair of acute complicated type B aortic dissection-systematic review and meta-analysis of long-term survival and reintervention

Background

Thoracic endovascular repair (TEVAR) is considered the first-line therapy in the repair of acute complicated type B aortic dissection (AC-BAD). Given the difficulty of designing randomized trials in this surgical cohort, long-term outcome data is limited. This systematic review and meta-analysis provide a complete aggregation of reported long-term survival and freedom from reintervention of AC-BAD patients based on the existing literature.

Methods

Three databases were searched from date of database inception to January 2021. The relevant references were identified and baseline cohort characteristics, survival and freedom from reintervention were extracted. The primary endpoints were survival and freedom from reintervention, whilst secondary endpoints were post-operative outcomes such as cord ischemia and endoleak. Kaplan-Meier curves were digitized and aggregated as per established procedure.

Results

A total of 2,812 references were identified in the literature search for review, with 46 selected for inclusion. A total of 2,565 patients were identified, of which 1,920 (75%) were male. The mean age of the cohort was 59.8±5.8. Actuarial survival at 2, 4, 6 and 10 years was 87.5%, 83.2%, 78.5% and 69.7%, respectively. Freedom from all secondary reintervention at 2, 4, 6, 8 and 10 years was 74.7%, 69.1%, 65.7%, 63.9% and 60.9%, respectively. When accounting for study quality, actuarial survival at 2, 4, 6 and 8 years was 85.4%, 79.1%, 69.8% and 63.1%, respectively. Freedom from all secondary reintervention at 2, 4, 6 and 8 years was 73.2%, 67.6%, 63.7% (maintained), respectively.

Conclusions

TEVAR is associated with promising long-term survival extended to 10 years, though rates of freedom from reintervention remain an ongoing point for improvement. Randomized controlled trials comparing endovascular with open repair in the setting of acute, complicated type B aortic dissection are needed.

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.

Laser-assisted "Scissor" Technique to Facilitate Thoracic Endovascular Aortic Repair for Chronic Type B Aortic Dissection

INTRODUCTION

There has been an increase in utilization of thoracic endovascular aortic repair (TEVAR) to treat aneurysms with chronic dissection. Despite significant progress, TEVAR is hindered by persistent perfusion of the false lumen and aneurysm growth. Various techniques to address false lumen perfusion exist. We preset our experience of laser fenestration with disruption of the dissection flap to facilitate TEVAR and avoid persistent retrograde false lumen perfusion.

METHODS

Review a technique to treat patients with thoracic aortic aneurysm complicated by chronic dissection. This is an adjunct to a TEVAR procedure with final goal to treat the aneurysm and avoid retrograde false lumen perfusion. Under IVUS guidance, we performed a Phillips/Spectranetics laser fenestration of the intimal flap followed by a scissoring technique to obliterate the dissection flap and create a distal seal zone. Stent-grafts placed following flap obliteration allow graft expansion and apposition to the entire outer aortic and avoid retrograde perfusion of the false lumen.

RESULTS

Two patients underwent TEVAR in conjunction with laser obliteration of the dissection flap, including one undergoing primary repair of a chronic Type B dissection with aneurysm, and one as a completion second stage elephant trunk procedure. Technical success was achieved in both cases, with successful implantation of the endograft, and freedom from type I and III endoleaks. Absence of false lumen flow, and patency of the visceral vessels was confirmed on completion angiography. True lumen patency and obliteration of the intimal flap were confirmed by IVUS. Early follow up confirms exclusion of the aneurysm, with no evidence of retrograde perfusion of the false lumen.

CONCLUSIONS

Thoracic aortic aneurysms in the context of chronic dissections can be successfully treated with TEVAR and laser obliteration of the chronic dissection flap to fully exclude the aneurysm and avoid retrograde false lumen perfusion.

Comparison of diametric and volumetric changes in Stanford type B aortic dissection patients in assessing aortic remodeling post-stent graft treatment

Background

The study aims to analyze the correlation between the maximal diameter (both axial and orthogonal) and volume changes in the true (TL) and false lumens (FL) after stent-grafting for Stanford type B aortic dissection.

Method

Computed tomography angiography was performed on 13 type B aortic dissection patients before and after procedure, and at 6 and 12 months follow-up. The lumens were divided into three regions: the stented area (Region 1), distal to the stent graft to the celiac artery (Region 2), and between the celiac artery and the iliac bifurcation (Region 3). Changes in aortic morphology were quantified by the increase or decrease of diametric and volumetric percentages from baseline measurements.

Results

At Region 1, the TL diameter and volume increased (pre-treatment: volume =51.4±41.9 mL, maximal axial diameter =22.4±6.8 mm, maximal orthogonal diameter =21.6±7.2 mm; follow-up: volume =130.7±69.2 mL, maximal axial diameter =40.1±8.1 mm, maximal orthogonal diameter =31.9+2.6 mm, P<0.05 for all comparisons), while FL decreased (pre-treatment: volume =129.6±150.5 mL; maximal axial diameter =43.0±15.8 mm; maximal orthogonal diameter =28.3±12.6 mm; follow-up: volume =66.6±95.0 mL, maximal axial diameter =24.5±19.9 mm, maximal orthogonal diameter =16.9±13.7, P<0.05 for all comparisons). Due to the uniformity in size throughout the vessel, high concordance was observed between diametric and volumetric measurements in the stented region with 93% and 92% between maximal axial diameter and volume for the true/false lumens, and 90% and 92% between maximal orthogonal diameter and volume for the true/false lumens. Large discrepancies were observed between the different measurement methods at regions distal to the stent graft, with up to 46% differences between maximal orthogonal diameter and volume.

Conclusions

Volume measurement was shown to be a much more sensitive indicator in identifying lumen expansion/shrinkage at the distal stented region.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Staged Hybrid Single Lumen Reconstruction (TIGER) in Management of Chronic Symptomatic Complex Type B Aortic Dissection, Techniques, and Literature Review

BACKGROUND

Endovascular intervention for chronic symptomatic type B aortic dissection (CS-TBAD) induces aortic wall stress with negative hemodynamic cardiovascular consequences. CS-TBAD risks increased morbidity and mortality due to septum maturation with significant impact on false lumen modulation, and partial lumen thrombosis conveying the worst outcome. The aim of the TIGER technique is total aortic remodeling with true lumen expansion, false lumen regression and complete thrombosis, and stabilization of overall aortic diameter.

METHODS

We report 5 cases of aortic dissection with a mean follow-up of 16 months (6-28 months). All had aneurysmal dilation, with 3 having acute pan aortic dissection and 2 having CS-TBAD. All were managed by sTaged HybrId sinGle lumEn Reconstruction (TIGER). Our first approach was to create one single lumen from the supraceliac, infradiaphragmatic aorta to both common iliac arteries with open surgical patching of the visceral arteries; then, we performed a TEVAR 3 months later.

RESULTS

Three patients required a left subclavian artery chimney graft and one required bilateral subclavian to carotid artery transposition. No spinal drainage was required, and all patients had intraoperative transesophageal echo for wire guidance. We had no aortic rupture or retrograde type A dissection, and we experienced no renal, visceral, cardiac, pulmonary, or spinal complications. All patients, but one, went off their antihypertensive medication. All patients had normal estimated glomerular filtration rate postoperatively, and they all demonstrated accelerated aortic modulation.

CONCLUSIONS

TIGER was not only effective at the semiacute stage to initiate remodeling and prevent malperfusion, it also facilitated a straightforward TEVAR at stage 2, which was made easier by avoiding visceral branch stenting. Moreover, it decreased the length of aortic segment, which was stented, thereby avoiding critical shattering, branch dislodgment, and visceral compromise; spinal ischemia; and negative cardiovascular consequences.

Long-Term Outcomes of Open Surgery and Stent Graft Treatment in Patients Undergoing Repeat Thoracic Aortic Aneurysm Repair from Previous Anastomosis Site

Objective: The purpose of this study was to compare the long-term outcomes of open surgery and thoracic endovascular aortic repair (TEVAR) in patients undergoing repeat thoracic aortic repair from previous anastomosis site.

Methods: From January 2009 to December 2017, 68 patients needed repeat aortic surgery from previous anastomosis site. Twenty-three patients had dissected distal aorta and 45 patients had non-dissected distal aorta. Early and long-term outcomes of open surgery and TEVAR were compared in both groups.

Results: There were no significant differences in patient background between the two treatments in both groups. Open surgery was associated with longer intensive care unit stay, but there was no significant difference in in-hospital mortality in both groups. In patients with dissected distal aorta, there was no significant difference in long-term mortality (p=0.73). However, TEVAR was associated with higher risk of reintervention (p=0.038). In non-dissected distal aorta patients, acute kidney injury (p=0.002) and prolonged ventilation (p=0.032) were more often observed in open surgery. However, there were no significant differences in long-term mortality (p=0.23) and freedom from reintervention (p=0.13).

Conclusions: Long-term outcomes were similar between open surgery and TEVAR in both groups. However, TEVAR in patients with dissected distal aorta was associated with higher risk, for reintervention.

Total Endovascular Repair With Parallel Stent-Grafts for Postdissection Thoracoabdominal Aneurysm After Prior Proximal Repair

Purpose: To evaluate the safety and efficacy of total endovascular repair with parallel stent-grafts for postoperative residual dissection thoracoabdominal aortic aneurysm (TAAA). Materials and Methods: A retrospective study was undertaken of 21 patients (mean age 64.0±12.5 years; 17 men) undergoing total endovascular therapy with parallel stent-grafts for postdissection TAAA after prior proximal repair between 2014 and 2016. The preoperative minimum true lumen diameter was 12.3±4.8 mm and the mean extent of dissection was 248.1±48.2 mm. Pre-, intra-, and postoperative medical records were reviewed to assess technical success, spinal cord ischemia, patency of target branch arteries, endoleak, and short-term outcomes of this approach. Results: Technical success was achieved in 17 of 21 patients owing to 4 type I endoleaks at the end of the procedures. A total of 70 branch arteries were revascularized and 14 celiac trunks were covered intentionally without reconstruction. Of 7 intraoperative endoleaks, 2 were managed intraoperatively and 5 (4 type I and 1 type II) disappeared spontaneously within 1 month. No spinal cord or abdominal organ or limb ischemia was observed. Mean follow-up was 16.2±6.1 months. No death or type I or III endoleak occurred during the follow-up; 2 type II endoleaks were observed. Nineteen of the 21 false lumens thrombosed, and the total aortic diameter decreased (57.3±8.4 to 55.3±7.4 mm, p<0.01). Three (4.3%) of 70 target branch arteries occluded during follow-up. The cumulative patency of retrogradely and antegradely revascularized branch arteries was 97.3% vs 100% at 12 months and 91.2% vs 100% at 18 months. Conclusion: Total endovascular therapy with parallel stent-grafts could be an effective alternative in treating postdissection TAAA. Further studies with long-term follow-up and larger sample size are recommended to evaluate the technique.

[Elimination of late endoleak after endovascular repair of a dissecting thoracoabdominal aortic aneurysm]

Described herein is a clinical case report regarding treatment of a 70-year-old male patient presenting with a late complication following endoprosthetic repair for a Stanford type B dissecting thoracic aortic aneurysm. The man was admitted to our hospital for persistent type IIb endoleak and an increased diameter of the aorta in its thoracic and thoracoabdominal portions. Two years previously, he had endured endoprosthetic repair of the thoracic aorta. The findings of computed tomography revealed negative dynamics manifesting as an increase in the diameter of the false channel of the arch and descending thoracic aorta with persistent type IIb endoleak. He was subjected to elimination of abdominal aortic dissection and type IIb endoleak with partial prosthetic repair of the descending thoracic portion of the aorta by means of prosthetic repair of the lower thoracic portion of the aorta between the stent graft and linear vascular Dacron prosthesis. The postoperative period was complicated by transient acute renal failure and paraparesis of the lower limbs. The patient was discharged on POD 14, with no endoleaks revealed on control computed tomography 3 months thereafter.

Temporal and Morphological Patterns Predict Outcome of Endovascular Repair in Acute Complicated Type B Aortic Dissection

OBJECTIVES

The aim was to analyse early and late outcomes in patients undergoing thoracic endovascular aortic repair (TEVAR) for acute or subacute non-traumatic type B aortic dissection (TBAD), with the particular aims of identifying prognostic morphological predictors, and to assess the magnitude of the impact of the timing of TEVAR.

METHODS

This was a retrospective, two centre, population based consecutive case series. The study group consisted of all the 53 patients undergoing TEVAR for complicated TBAD in Stockholm during the 12 year period 2004-2015. Demographic data, risk factors, operative, and outcome variables were registered and analysed. The CT scans were thoroughly retrospectively examined.

RESULTS

Nearly half (24 patients; 45%) underwent TEVAR within 48 h of the onset of the initial symptoms, another 20 within 2 weeks, and nine in the subacute phase (15-90 days). The median age was 63 years (range 32-88) and 20 patients (38%) were women. The 30 day mortality was 17% (nine patients). Eight of these nine patients were treated within the first 48 h; urgent intervention (0-48 h) was associated with increased mortality (crude OR 14.0; 95% CI 1.6-122). All the nine patients had a false lumen area (FLA) at the level of the tracheal bifurcation exceeding 50% of the aortic cross sectional area at that segment, a finding significantly associated with increased mortality (p = .04), with a 25% 30 day mortality if the FLA > 50% (n = 36) at that segment, but 0% if the FLA was <50%. Overall the one year survival was 79% and five year survival 65%.

CONCLUSIONS

All the early deaths demonstrated a FLA >50% of the total aortic cross sectional area at the level of the tracheal bifurcation. Patients needing urgent TEVAR had markedly worse outcome. The first finding may become an additional tool for future risk stratification.

Flow pattern analysis in type B aortic dissection patients after stent-grafting repair: Comparison between complete and incomplete false lumen thrombosis

Endovascular stent graft repair has become a common treatment for complicated Stanford type B aortic dissection to restore true lumen flow and induce false lumen thrombosis. Using computational fluid dynamics, this study reports the differences in flow patterns and wall shear stress distribution in complicated Stanford type B aortic dissection patients after endovascular stent graft repair. Five patients were included in this study: 2 have more than 80% false lumen thrombosis (group 1), while 3 others had less than 80% false lumen thrombosis (group 2) within 1 year following endovascular repair. Group 1 patients had concentrated re-entry tears around the abdominal branches only, while group 2 patients had re-entry tears that spread along the dissection line. Blood flow inside the false lumen which affected thrombus formation increased with the number of re-entry tears and when only small amounts of blood that entered the false lumen exited through the branches. In those cases where dissection extended below the abdominal branches (group 2), patients with fewer re-entry tears and longer distance between the tears had low wall shear stress contributing to thrombosis. This work provides an insight into predicting the development of complete or incomplete false lumen thrombosis and has implications for patient selection for treatment.

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.

Hybrid Approach of Aortic Diseases: Zone 1 Delivery and Volumetric Analysis on the Descending Aorta

Introduction

Conventional techniques of surgical correction of arch and descending aortic diseases remains as high-risk procedures. Endovascular treatments of abdominal and descending thoracic aorta have lower surgical risk. Evolution of both techniques - open debranching of the arch and endovascular approach of the descending aorta - may extend a less invasive endovascular treatment for a more extensive disease with necessity of proximal landing zone in the arch.

Objective

To evaluate descending thoracic aortic remodeling by means of volumetric analysis after hybrid approach of aortic arch debranching and stenting the descending aorta.

Methods

Retrospective review of seven consecutive patients treated between September 2014 and August 2016 for diseases of proximal descending aorta (aneurysms and dissections) by hybrid approach to deliver the endograft at zone 1. Computed tomography angiography were analyzed using a specific software to calculate descending thoracic aorta volumes pre- and postoperatively.

Results

Follow-up was done in 100% of patients with a median time of 321 days (range, 41-625 days). No deaths or permanent neurological complications were observed. There were no endoleaks or stent migrations. Freedom from reintervention was 100% at 300 days and 66% at 600 days. Median volume reduction was of 45.5 cm³, representing a median volume shrinkage by 9.3%.

Conclusion

Hybrid approach of arch and descending thoracic aorta diseases is feasible and leads to a favorable aortic remodeling with significant volume reduction.

Retrograde Type A Aortic Dissection After Thoracic Endovascular Aortic Repair: A Systematic Review and Meta-Analysis

Background

Retrograde type A aortic dissection (RTAD) is a potentially lethal complication after thoracic endovascular aortic repair (TEVAR). However, data are limited regarding the development of RTAD post‐TEVAR. This systematic review aims to define the incidence, mortality, and potential risk factors of RTAD post‐TEVAR.

Methods and Results

Multiple electronic searches were performed. Fifty publications with a total of 8969 patients were analyzed. Pooled estimates for incidence and mortality of RTAD were 2.5% (95% confidence interval [CI], 2.0–3.1) and 37.1% (95% CI, 23.7–51.6), respectively. Metaregression analysis evidenced that RTAD rate was associated with hypertension (P=0.043), history of vascular surgery (P=0.042), and American Surgical Association (P=0.044). The relative risk of RTAD was 1.81 (95% CI, 1.04–3.14) for acute dissection (relative to chronic dissection) and 5.33 (95% CI, 2.70–10.51) for aortic dissection (relative to a degenerative aneurysm). Incidence of RTAD was significantly different in patients with proximal bare stent and nonbare stent endografts (relative risk [RR]=2.06; 95% CI, 1.22–3.50). RTAD occurrence rate in zone 0 was higher than other landing zones.

Conclusions

The pooled RTAD rate after TEVAR was calculated at 2.5% with a high mortality rate (37.1%). Incidence of RTAD is significantly more frequent in patients treated for dissection than those with an aneurysm (especially for acute dissection), and when the proximal bare stent was used. Rate of RTAD after TEVAR varied significantly according to the proximal Ishimaru landing zone. The more‐experienced centers tend to have lower RTAD incidences.

Aortic Remodeling Following Sun's Procedure for Acute Type A Aortic Dissection

Background

Sun’s procedure is a surgical technique widely used in type A aortic dissection. The purpose of this study was to analyze clinical outcomes and morphologic changes in true and false lumen by computed tomography (CT) angiography after Sun’s procedure.

Material/Methods

We retrospectively reviewed 51 patients who underwent Sun’s procedure for acute Stanford type A aortic dissection extending down to iliac bifurcation between January 2013 and December 2014. The images of preoperative, one-month, three-month, and six-month follow-up were analyzed by CT angiography to measure the area and diameter of true and false lumen.

Results

Four patients died before surgical intervention and postoperative deaths occurred in five patients (in-hospital mortality rate 10.6%). Only 42 patients (36 male, 6 female; mean age, 45.9±9.8 years; range, 24–65 years) with acute type A aortic dissection were involved in our study. Thirty-five patients (83.3%) suffered from chest or abdominal pain and only one patient (2.4%) was asymptomatic. Thirty-seven patients (88.1%) had hypertension as the most common comorbidity. In the ascending aorta, false lumen was eliminated and the change of true lumen was not significant (p>0.05). In the descending aorta, complete and partial thrombosis of false lumen were observed in eight patients (19.0%) and 33 patients (78.6%) by one-month follow-up CT scan, respectively. After the six-month follow-up, the rate of complete thrombosis increased to 36.1% and partial thrombosis decreased to 61.9%. The area and maximal diameter of true lumen were increased significantly (p<0.05), whereas significant decreases were found in the area and maximal diameter of false lumen (p<0.05). In the abdominal aorta, thrombosis was found in 52.4% patients at one-month follow-up CT. Furthermore, there were no significant changes in both true and false lumen within three months (p>0.05). Nevertheless, the false luminal area and maximal diameter decreased significantly (p<0.05) after six months, while these changes of true lumen were not significant (p>0.05).

Conclusions

After Sun’s procedure, aortic remodeling was a continuous process and occurred in a predictable model, and the extent of aortic remodeling varied at different levels. Remodeling in descending thoracic aorta was earlier than it was in abdominal aorta.

Technical Aspects of Open Repair for Degenerative Aneurysmal Evolution Despite Early Thoracic Endovascular Repair of Type B Aortic Dissection

BACKGROUND

Closure of the proximal tear by thoracic endovascular aortic repair (TEVAR) at the acute phase appears to be a safe effective treatment to prevent aneurysmal degeneration type B dissection. However, it appears to be inefficient in up to a third of the patient. We report the technical aspects of our experience with patients undergoing secondary open repair after TEVAR for dissecting thoracoabdominal aneurysm despite early closure proximal tear by TEVAR.

METHODS

During a period of 5 years, 96 patients presenting acute type B aortic dissections were treated by TEVAR and followed-up in our institution. Among them, 5 patients experienced an evolution to a dissecting thoracoabdominal aortic aneurysm. Their demographic data and initial medical conditions, delay to reintervention, operative technical details, perioperative and mid-term outcomes were collected and analyzed.

RESULTS

All 5 patients (4 male, mean age 58 ± 9) were operated under peripheral normothermic bypass without deep circulatory arrest using the thoracic stent graft as an elephant trunk for completion of the proximal anastomosis. In cases of patency, the false lumen was reapproximated in the anastomosis, 6 visceral arteries were revascularized selectively. One patient died at day 1 of perioperative ventricular fibrillation due to an acute myocardial infarction. The 4 others are alive without complication after a median of 30 months, range (13-22).

CONCLUSIONS

In our experience, TEVAR was not only efficient at the acute phase to deal with complications, but in cases of subsequent aneurysmal evolution, it made open repair even easier by avoiding very proximal cross-clamping/anastomosis and circulatory arrest.

Frequency of abdominal aortic expansion after thoracic endovascular repair of type B aortic dissection

Purpose

To determine abdominal aortic expansion after thoracic endovascular aortic repair (TEVAR) in patients with aortic dissection type B and 36 months minimum follow-up.

Methods

Retrospective study of 18 TEVAR patients with follow-up >36 months. Abdominal aortic diameters at celiac trunk (location B) and infrarenal aorta (location C) were recorded on the first and last imaging after TEVAR. False lumen thrombosis was determined at level of endograft (A) and at B and C. Aortic expansion was defined as diameter increase of 5 mm or 15%. Correlation analyses were performed to investigate potential determinants of expansion.

Results

Median follow-up was 75.2 months. Sixteen of 18 patients (88.9%) demonstrated abdominal expansion. Mean expansion was 9.9 ± 6.1 mm at B and 11.7 ± 6.5 mm at C, without a difference between acute and chronic dissections. Critical diameters of 55 mm were reached in two patients treated for chronic dissection (11.1%). Annual diameter increase was significantly greater at locations with baseline diameters >30 mm (2.1 ± 1.1 mm vs. 1.0 ± 0.6 mm, p = 0.009). Baseline diameters were greater in patients with chronic dissections.

Conclusion

Abdominal aortic expansion can be frequently recognized after TEVAR for aortic dissection type B and occurs independently from thoracic false lumen thrombosis. Clinical significant abdominal aortic expansion may occur more frequently in patients treated with TEVAR for chronic dissection.

Influence of distal extension of false lumen on adverse aortic events after TEVAR in patients with acute type B aortic dissection

OBJECTIVE

To investigate the clinical outcomes influenced by distal extension of false lumen in acute type B aortic dissection (TBAD) patients following thoracic endovascular aortic repair (TEVAR).

METHODS

From April 2002 to January 2013, 264 TBAD patients treated with TEVAR were retrospectively enrolled. The IIIa group exhibited a distal false lumen above the diaphragm (n = 70), and the IIIb group exhibited a distal false lumen under the diaphragm (n = 194). The morphological characteristics and adverse events (30-day and >30 days) were recorded and evaluated.

RESULTS

There were no significant differences between the two groups regarding the demographics, comorbidity profiles, or initial feature of computed tomography angiography. The incidence of true lumen compression and branch involvement were significantly increased in the IIIb group compared with the IIIa group (8.6% vs. 25.3%, respectively; 15.7% vs. 36.1%, respectively, both P < 0.05). The 30-day mortality rate was 1.0% (2/194) in the IIIb group, whereas the IIIa group was zero. The incidence of early adverse events, the 5-year cumulative freedom from adverse events, and the 5-year cumulative freedom from all-cause mortality rate were not significantly different between the IIIa and IIIb groups (2.9% vs. 6.7%, 81.4%, and 80.4%, and 95.7% vs. 93.8%, respectively, all P > 0.05). Log-rank tests also indicated there was no significant difference.

CONCLUSIONS

There was no significant difference between the IIIa and IIIb groups in the 5-year morality and adverse aortic events following TEVAR. The distal extension of false lumen prior to TEVAR does not influence the long-term morality and adverse aortic events in acute TBAD.

Spinal cord injury following thoracic and thoracoabdominal aortic repairs

Objective

To discuss the currently available approaches to prevent spinal cord injury during thoracic and thoracoabdominal aortic repairs.

Methods

We carried out a PubMed search up to 2013 using the Medical Subject Headings: “aortic aneurysm/surgery” and “spinal cord ischemia”; “aortic aneurysm, thoracic/surgery” and “spinal cord ischemia”; “aneurysm/surgery” and “spinal cord ischemia/cerebrospinal fluid”; “aortic aneurysm/surgery” and “paraplegia”. All 190 original articles satisfying our inclusion criteria were analyzed for incidence, predictors, and other pertinent variables related to spinal cord injury, and we compared the results in recent publications with those in earlier reports.

Results

The mean age of the 38,491 patients was 65.3 ± 4.9 years. The overall incidence of paraplegia and/or paraparesis was 7.1% ± 6.1% (range 0%–32%). The incidence of spinal cord injury before 2000, from 2001 to 2007, and 2008–2013 was 9.0% ± 6.7%, 7.0% ± 6.1%, and 5.9% ± 5.2%, respectively ( p = 0.019). Various predictors of spinal cord injury were identified, extent of disease being the most common. Modification of surgical techniques, use of adjuncts, and better understanding of spinal cord perfusion physiology were attributed to the decrease in postoperative spinal cord injury in recent years.

Conclusions

Spinal cord injury after thoracic and thoracoabdominal aortic repair poses a real challenge to cardiovascular surgeons. However, with evolving surgical strategies, identification of predictors, and use of various adjuncts over the years, the incidence of spinal cord injury after thoracic/thoracoabdominal aortic repair has declined. Embracing a multimodality approach offers a good insight into combating this grave complication.

Increasing prevalence of hypertension among patients with thoracic aorta dissection: trends over eight decades--a structured meta-analysis

BACKGROUND

This structured metaanalysis focused on determining the relationship between hypertension (HTN) and thoracic aortic dissection (TAD).

METHODS

Electronic searches were conducted using the MedLine database, for the period 1946 through May 2013, and manual searches from reference lists. Demographic data, patient diagnosis, and HTN prevalence were extracted from each study. Data were analyzed using weighted averages, metaanalysis, analysis of variance, trend analysis, and multivariate analysis.

RESULTS

A total of 8,086 cases of TAD from 75 studies over eight decades were assessed. Overall prevalence of HTN in TAD was 66.7% ± 17.5%. An increase of approximately 5.6% in HTN prevalence in TAD cases occurred in every decade. Prevalence of HTN in type A dissections steadily increased, with an overall prevalence of 64.8% ± 21.3%, while in type B dissections, prevalence abruptly increased from 1950 to 1970 and remained constant thereafter, with an overall prevalence of 78.7% ± 8.6%. Trend analysis demonstrated significant (P < 0.001) and linear increasing trends for the prevalence of HTN and age at presentation. Multivariate analysis demonstrated that a history of HTN was significantly (P < 0.001) associated with increasing trends of over time, which was independent of the relationship between age and TAD.

CONCLUSIONS

The proportion of TAD patients with HTN has been increasing over eight decades. Age at presentation of TAD has also been incrementally increasing, but the increase in HTN was independent of age in multivariate analysis. The trend for increasing HTN prevalence was more evident in type A TAD. These data highlight a need to focus on HTN management in patients with thoracic aortic aneurysm.

Stent graft therapy for false lumen aneurysmal degeneration in established type B aortic dissection (FADED) results in differential volumetric remodeling of the thoracic versus abdominal aortic segments

BACKGROUND

Despite optimal medical therapy of type B aortic dissections, false lumen aneurysmal degeneration of these established dissections (FADED) occur over long term (>6 months). The efficacy of thoracic stent grafts (thoracic endovascular aortic repair [TEVAR]) in promoting aortic remodeling when placed at late time points remains controversial and was the focus of this investigation.

METHODS

Utilizing tomographic scans, the volume of 6 distinct aortic compartments were calculated including the stented true lumen and stented false lumen (STL and SFL), below-stent true and false lumens (BSTL and BSFL), and the infrarenal aorta true and false lumens (IRA TL and IRA FL) when applicable. Cross-sectional areas were calculated at 1-cm intervals, collated, and volumetric ratios were derived from preoperative values.

RESULTS

From 2004 to 2011, 21 patients met inclusion criteria. Complete false lumen (FL) thrombosis was achieved in 85.7% of SFL and 26.3% of BSFL. Volumetric analysis demonstrated that 71% of patients had increased STL volume and 71% had decreased SFL. In the below-stent region, 75% of patients had increased true lumen (TL) with 59% concurrently decreased FL volume. The IRA TL volume increased in 85% of patients and the IRA FL also expanded in 75% of this cohort. At the latest time point, overall growth was noted in the infrarenal aortic segment.

CONCLUSIONS

Utilization of TEVAR in patients suffering from FADED can promote TL expansion with concurrent FL regression; however, progressive dilation in the total infrarenal aorta volume may occur and warrants close surveillance.

A systematic review of aortic remodeling after endovascular repair of type B aortic dissection: methods and outcomes

BACKGROUND

Endovascular treatments of Stanford type B aortic dissection may help to promote aortic remodeling and reduce the incidence of aortic-related complications. The aim of this study was to review published literature describing aortic remodeling after endovascular treatment of aortic dissection.

METHODS

A systematic review of the literature was performed which was compliant with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The type of aortic morphology measurements made and the methods used to make them were characterized. The endpoints of interest were the change in these measurements over time.

RESULTS

After initial screening, 77 articles were identified; 16 of which met the inclusion criteria. Few studies used three-dimensional reconstruction software and none had validated their measurement protocol. True lumen (TL) and false lumen (FL) diameters, areas, and in some cases volumes were measured. Studies assessed the aorta at a variety of different levels and over different periods of follow-up. Acute dissection patients displayed more consistent degree of remodeling (thoracic FL thrombosis in 80% to 90%) than chronic dissection patients (38% to 91%). Less remodeling was seen below the diaphragm in both groups.

CONCLUSIONS

Aortic remodeling after treatment for dissection is described in a highly heterogeneous manner. Despite this there appears to be a greater degree of complete FL resolution in patients with acute dissection than chronic. Factors such as length of aortic coverage and timing of treatment may explain the variation seen in the chronic dissection group. Consensus-based reporting standards are required to synthesize evidence and inform clinical decisions regarding patient selection and operative timing.

Endovascular repair of type B aortic dissection: long-term results of the randomized investigation of stent grafts in aortic dissection trial

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) represents a therapeutic concept for type B aortic dissection. Long-term outcomes and morphology after TEVAR for uncomplicated dissection are unknown.

METHODS AND RESULTS

A total of 140 patients with stable type B aortic dissection previously randomized to optimal medical treatment and TEVAR (n=72) versus optimal medical treatment alone (n=68) were analyzed retrospectively for aorta-specific, all-cause outcomes, and disease progression using landmark statistical analysis of years 2 to 5 after index procedure. Cox regression was used to compare outcomes between groups; all analyses are based on intention to treat. The risk of all-cause mortality (11.1% versus 19.3%; P=0.13), aorta-specific mortality (6.9% versus 19.3%; P=0.04), and progression (27.0% versus 46.1%; P=0.04) after 5 years was lower with TEVAR than with optimal medical treatment alone. Landmark analysis suggested a benefit of TEVAR for all end points between 2 and 5 years; for example, for all-cause mortality (0% versus 16.9%; P=0.0003), aorta-specific mortality (0% versus 16.9%; P=0.0005), and for progression (4.1% versus 28.1%; P=0.004); Landmarking at 1 year and 1 month revealed consistent findings. Both improved survival and less progression of disease at 5 years after elective TEVAR were associated with stent graft induced false lumen thrombosis in 90.6% of cases (P<0.0001).

CONCLUSIONS

In this study of survivors of type B aortic dissection, TEVAR in addition to optimal medical treatment is associated with improved 5-year aorta-specific survival and delayed disease progression. In stable type B dissection with suitable anatomy, preemptive TEVAR should be considered to improve late outcome.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT01415804.

Successful remodeling and endovascular repair of a ruptured type B chronic aortic dissection 12 years after primary surgery

A 70-year-old woman with a medical history of descending aorta replacement for chronic type B aortic dissection 12 years prior was admitted to our hospital with sudden back pain and hemoptysis. The patient was diagnosed with ruptured residual dissected thoracic aortic aneurysm and underwent emergent endovascular treatment. Two TAG thoracic endoprosthesis of different sizes were used to accommodate the discrepancy in size of the true lumen, resulting in a successful closure of the entry tear and hemostasis, without any damage to the intima. Computed tomography performed 3 months after surgery revealed successful remodeling of the remaining aorta. Thoracic endovascular aortic replacement may be considered as an option in the treatment of chronic dissected aortic aneurysm, achieving not only entry closure but possibly remodeling, as well.