Endovascular repair of acute uncomplicated aortic type B dissection promotes aortic remodelling: 1 year results of the ADSORB trial

Acute aortic syndromes: a review of what we know and future considerations

Acute aortic syndromes represent a spectrum of life-threatening aortic pathologies. Prompt diagnosis and proper management of these syndromes are important in reducing overall mortality and morbidity, which remains high. Acute aortic dissections represent most of these aortic wall pathologies, but intramural haematomas and penetrating atherosclerotic ulcers have been increasingly diagnosed. Type A dissections require prompt surgical treatment, with endovascular options on the horizon. Type B dissections can be complicated or uncomplicated, and treatment is determined based on this designation. Complicated Type B dissections require prompt repair with thoracic endovascular aortic repair (TEVAR) becoming the preferred method. Uncomplicated Type B dissections require medical management, but early TEVAR in the subacute setting is becoming more prominent. Proper surveillance for an uncomplicated Type B dissection is crucial in detecting aortic degeneration and need for intervention. Intramural haematomas and penetrating atherosclerotic ulcers are managed similarly to aortic dissections, but more research is needed to determine the proper management algorithms. Multi-disciplinary aortic programmes have been shown to improve patient outcomes and are necessary in optimizing long-term follow-up.

Aortic-related Readmission after Thoracic Endovascular Aortic Repair for Type B Aortic Dissection Patients: A Single-center Retrospective Study

OBJECTIVES

This study aimed to investigate the characteristics of and risk factors for aortic-related readmission after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD).

METHODS

Data from TBAD patients who underwent TEVAR from 2009-2018 at a Chinese tertiary center were retrospectively collected and analyzed. Enrolled patients were categorized into two groups according to whether aortic-related readmission occurred during follow-up, which was defined as hospitalization at least once after the initial procedure due to events that were related to or caused by aortic dissection or the initial procedure.

RESULTS

A total of 1 288 TBAD patients were enrolled, and 99 patients experienced aortic-related readmissions (7.7%), among whom chronic patients had the highest readmission rate (9.8%). The yearly proportion of readmission during the first year after initial procedure revealed a decreasing trend with a -9.7% annual percentage change. Seventy-one patients underwent reintervention (71.7%). Distal aneurysmal degeneration (43.7%) and distal stent graft-induced new entries (32.4%) were two major causes for reintervention. Fourteen patients in the reintervention subgroup underwent a second reintervention (19.7%). In-hospital mortality was 1.0% during the readmission and 14.3% during the second readmission. The overall survival was comparable between two groups (p=.93).

CONCLUSIONS

This study highlighted the importance of surveillance after initial procedure for TBAD patients with potential risk factors for aortic-related readmission, and the predisposition of patients with reintervention to multiple readmissions deserves attention.

Acute Aortic Syndromes

Acute aortic syndromes, classified into aortic dissection, intramural hematoma, and penetrating aortic ulcer, are associated with high early mortality for which early diagnosis and management are crucial to optimize outcomes. Patients often present with nonspecific clinical symptoms and signs; therefore, it is important for providers to maintain a high index of suspicion for acute aortic syndromes. Electrocardiogram-gated computed tomographic angiography of the chest, abdomen, and pelvis is currently the most practical imaging modality for diagnosis and identification of complications. Evolution in surgical techniques and the development of aortic endografts have improved patient outcomes, but randomized trials are still needed.

Timing of endovascular repair impacts long-term outcomes of uncomplicated acute type B aortic dissection

OBJECTIVE

To compare the 5-year outcomes of acute versus subacute thoracic endovascular aortic repair (TEVAR) in patients with uncomplicated acute type B aortic dissection (ATBAD).

METHODS

Between March 2008 and September 2018, 238 consecutive patients with uncomplicated ATBAD underwent TEVAR in the acute or subacute phase and were analyzed retrospectively. The primary end points were all-cause death and aortic-related death. The secondary end point was a composite of the outcomes of death from any cause, rupture, new dissection, retrograde type A aortic dissection, endoleak, and late reintervention. Inverse probability treatment weighting was used to balance baseline characteristics. Weight-adjusted Kaplan-Meier estimate with landmark analysis and weighted Cox model were performed to assess time-to-event outcomes.

RESULTS

In the inverse probability treatment weighting-adjusted population, the 30-day mortality was 1.5% in the acute TEVAR group and 0% in the subacute TEVAR group (P = .24). The incidence of 30-day adverse events occurred in 16.8% and 6.9% patients in the acute TEVAR and subacute TEVAR groups, respectively (P = .13). At 5 years, there was no statistically significant difference in all-cause death (hazard ratio [HR], 1.50; 95% confidence interval [CI], 0.59-3.81; P = .39) and aortic-related death (HR, 1.11; 95% CI, 0.34-3.60; P = .86) between the two groups. The composite outcomes occurred in 30 patients (23.0%) in the acute TEVAR group and 18 patients (22.3%) in the subacute TEVAR group, respectively (HR, 0.67; 95% CI, 0.36-1.25; P = .20). However, a landmark analysis of the composite outcomes indicated that there was a significant interaction between treatment effect and time (P_interaction = .01), with a significantly higher incidence of the composite outcomes in the acute TEVAR group compared with the subacute TEVAR group within 1 year (HR, 0.25; 95% CI, 0.08-0.79; P = .02), and a comparable rate between 1 and 5 years (HR, 1.25; 95% CI, 0.56-2.76; P = .59).

CONCLUSIONS

At the 5-year follow-up, no significant differences exist in the all-cause death and aortic-related death between acute and subacute TEVAR. However, acute TEVAR is associated with an increased rate of severe complications within 1 year, which suggests that performing TEVAR in the subacute phase of ATBAD may be the preferable option.

Outflow Through Aortic Side Branches Drives False Lumen Patency in Type B Aortic Dissection

Objective: Thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) aims to induce false lumen (FL) thrombosis by sealing intimal tears between the true (TL) and the FL, and blocking the inflow into the FL. Incomplete thrombosis of the FL is correlated with poor clinical outcome. We hypothesize that the number of major and minor branches arising from the FL affects FL patency and may negatively influence TEVAR induced FL thrombosis.

Methods: Computed tomography (CT)-scans from 89 patients diagnosed with TBAD [best medical treatment (BMT) n = 52, TEVAR n = 37] from two high-volume vascular surgery centers were analyzed retrospectively. Analysis included evaluation of the FL patency status, the number, location and size of intimal tears, and the presence of minor and major side branches originating from the FL. Multiple regression analysis was conducted to evaluate obtained parameters as predictors for FL thrombosis status.

Results: In univariate analysis, the strongest correlation for FL patency was found for the number of major (R = 0.79) and minor (R = 0.86) side branches originating from the FL. When applying a multiple linear regression model, the number of major (normalized beta 0.37; P < 0.001) and minor (normalized beta 0.41; P < 0.01) side branches arising from the FL were valid predictors for the axial length of the patent and non-patent FL, and additionally determined the length of the patent FL at 12-month follow-up in patients that underwent TEVAR.

Conclusions: Our data suggest that the number of minor side branches that originate from the FL in TBAD is an important determinant of FL patency, to a greater degree than previously assumed.

IMPACT OF THORACIC ENDOVASCULAR AORTIC REPAIR TIMING ON AORTIC REMODELING IN ACUTE TYPE B AORTIC INTRAMURAL HEMATOMA

INTRODUCTION

Thoracic endovascular aortic repair (TEVAR) is increasingly utilized in the management of acute type B aortic intramural hematoma (TBIMH). Optimal timing for intervention has not been described. The aim of this study was to evaluate TEVAR timing on post-operative aortic remodeling.

METHODS

A retrospective chart review was performed on patients who underwent TEVAR for TBIMH from January 2008 to September 2018. Imaging was reviewed pre- and postoperatively. Primary data points included true lumen diameter (TLD) and total aortic diameter (TAD) at the site of maximal pathology. Primary endpoint was aortic remodeling evidenced by a TAD/TLD ratio closest to 1.0. Secondary outcome was occurrence of aortic-related adverse events and mortality (AREM): aortic rupture, aortic-related death, progression to dissection or need for aortic re-intervention within 12 months. Patients undergoing emergent TEVAR (within 24 hours, 'eTEVAR') were compared to the remainder - delayed TEVAR ('dTEVAR').

RESULTS

We analyzed 71 patients that underwent TEVAR FOR TBIMH; 25 underwent emergent TEVAR and 46 patients underwent dTEVAR (median: 5.5 days, range: 2-120 days). There were no differences in demographics and comorbidities and patients did not differ in presenting IMH thickness (12.6±3.1 mm vs. 11.3±4.1 mm, p=0.186) nor presenting TAD/TLD ratio (1.535±0.471 vs. 1.525±0.397, p=0.928) for eTEVAR and dTEVAR groups, respectively. eTEVAR patients had larger average presenting maximal descending aortic (DTA) diameter (45.8±14.3 mm vs. 38.2±7.5 mm, p=0.018) and higher incidence of penetrating aortic ulcer (PAU) on presenting CT angiography (52.0% vs 21.7%, p=0.033). Thirty day mortality was 2/25 (8.0%) for eTEVAR and 2/45 (4.4%) for dTEVAR (p=0.602). Postoperative aortic remodeling was more complete in the dTEVAR group (1.23±0.12 vs. 1.33±0.15, p=0.004). Case-control matching (controlling for presenting DTA diameter and PAU) on 30 patients still showed better aortic remodeling in the dTEVAR group (1.125±0.100 vs 1.348±0.42, p<0.001). The incidence of AREM was higher in the eTEVAR - 6/25 (24.0%) - group compared to the dTEVAR group - 2/46 (4.3%). At 12 months, freedom from AREM was higher in the dTEVAR group (95.7% vs. 76.0%, p=0.011). Postoperative TAD/TLD ratio was the best predictor for late aortic-related adverse events (AUROC=0.825, p=0.003).

CONCLUSION

TEVAR for acute type B IMH within 24 hours of admission is associated with lower aortic remodeling and higher occurrence of late aortic related adverse events and mortality. Delaying TEVAR when clinically possible could improve aortic remodeling and aortic-related outcomes.

Successful surgical repair of traumatic aortic dissection utilizing the Najuta stent graft in a patient with pre-existing situs inversus and anomalous neck vessels

We report the case of a 39-year-old man who underwent surgical repair for traumatic Stanford type B acute aortic dissection. He was involved in a traffic accident, resulting in multiple rib fractures and a sternum fracture. On investigation, he was also found to have anatomical anomalies, namely, situs inversus and abnormality in the aortic arch and neck vessels. Thoracic endovascular aortic repair was performed as it is a less invasive procedure, thus recommended in such cases. A fenestrated thoracic endovascular aortic repair using the Najuta stent graft was found to be effective in this case where the anomalous anatomy was pre-existing.

Risk factors for incomplete thrombosis in false lumen in sub-acute type B aortic dissection post-TEVAR

There is scarce information about the risk factors for incomplete false lumen thrombosis (FLT) among type B aortic dissection (AD) patients, particularly in the sub-acute phase following thoracic endovascular aortic repair (TEVAR). We enrolled consecutive sub-acute type B AD patients at Xinqiao Hospital (Chongqing, China) from May 2010 to December 2019. Patients with severe heart failure, cancer, and myocardial infarction were excluded. The postoperative computed tomography angiography (CTA) data were extracted from the most recent follow-up aortic CTA. Multivariate logistic regressions were applied to identify the association between FLT and clinical or imaging factors. Fifty-five subjects were enrolled in our study. Twelve participants showed complete FLT, and 2 of these died during the follow-up, while 8 patients died in incomplete FLT group. In the multivariate analysis, maximum abdominal aorta diameter (OR 1.20, 95% CI 1.016-1.417 p = 0.032) and the number of branches arising from the false lumen (FL) (OR 15.062, 95% 1.681-134.982 p = 0.015) were significantly associated with incomplete FLT. The C-statistics was 0.873 (95% CI 0.773-0.972) for the model. The FL diameter (p < 0.001) was significantly shorter following TEVAR, while the true lumen diameter (p < 0.001) and maximum abdominal aorta diameter (p = 0.011) were larger after the aortic repair. There were 21.8% of sub-acute type B AD patients presented complete FLT post-TEVAR. Maximum abdominal aorta diameter and the number of branches arising from the FL were independent risk factors for incomplete FLT. The true lumen diameter, maximum abdominal aorta diameter, and FL diameter changed notably following TEVAR.

Endovascular repair of the aortic arch: State of the art

BACKGROUND

Open total arch replacement remains the gold standard treatment for aneurysms and dissections involving the aortic arch. However, high-risk surgical candidates may benefit from endovascular techniques to reduce the risk of perioperative mortality and morbidity, especially neurologic complications. Numerous endografts are available for investigational use in the aortic arch as part of investigational device exemption (IDE) programs. Some devices are fenestrated or scalloped, while others are branched, ranging from single branch to triple branch stent-grafts. Furthermore, chimney techniques and in situ fenestration may be utilized in bailout or emergent situations.

RESULTS

Initial results describing outcomes of complete endovascular repair of the aortic arch are encouraging, with current data estimating that technical success ranges from 84.2% to 100%. Moreover, operative mortality may be as high as 13.2%, while neurologic complications also remain common, with stroke rates being as high as 20% and spinal cord ischemia being as high as 3.1%. However, more data are necessary to determine the comparative treatment effect of endovascular stent-grafting of the aortic arch, compared with conventional open and hybrid repairs. Longitudinal follow-up is also lacking, which will determine the long-term durability of endografts in the aortic arch. Nevertheless, endovascular repair represents an important opportunity for improving outcomes in patients with complex and potentially devastating pathologies of the aortic arch.

Results of a prospective follow-up study after type A aortic dissection repair: a high rate of distal aneurysmal evolution and reinterventions

OBJECTIVES

We investigated the anatomical evolution of residual aortic dissection after type A repair and factors associated with poor prognosis at a high-volume aortic centre.

METHODS

Between 2017 and 2019, all type A aortic dissections were included for prospective follow-up. Patients without follow-up computed tomography (CT) scan available for radiological analysis and patients without residual aortic dissection were excluded from this study. The primary end point was a composite end point defined as dissection-related events including aneurysmal evolution (increased diameter > 5 mm/year), aortic reintervention for malperfusion syndrome, aortic diameter >55 mm, rapid aortic growth >10 mm/year or aortic rupture and death. The secondary end points were risk factors for dissection-related events and reintervention analysis. All immediate and last postoperative CT scans were analysed.

RESULTS

Among 104 patients, after a mean follow-up of 20.4 months (8-41), the risk of dissection-related events was 46.1% (48/104) and the risk of distal reintervention was 17.3% (18/104). Marfan syndrome (P < 0.01), aortic bicuspid valve (P = 0.038), innominate artery debranching (P = 0.025), short aortic cross-clamp time (P = 0.011), initial aortic diameter >40 mm (P < 0.01) and absence of resection of the primary entry tear (P = 0.015) were associated with an increased risk of dissection-related events or reintervention during follow-up.

CONCLUSIONS

Residual aortic dissection is a serious disease requiring close follow-up at an expert centre. This study shows higher reintervention and aneurysmal development rates than currently published. To improve long-term outcomes, the early demographic and anatomic poor prognostic factors identified may be used for more aggressive treatment at an early phase.

TEVAR for complicated and uncomplicated type B aortic dissection-Systematic review and meta-analysis

BACKGROUND

Type B aortic dissection (TBAD), is defined as a dissection involving the aorta distal to left subclavian artery with the ascending aorta and the aortic arch not affected. TBAD is classified due to the time frame and presence of complications. Complicated TBAD (co-TBAD) patients have a greater mortality rate than uncomplicated TBAD (un-TBAD) and thoracic endovascular aortic repair (TEVAR) is considered the gold-standard intervention for these clinical challenges.

METHODS

We undertook a systematic review of the literature regarding TEVAR intervention in co-TBAD and un-TBAD. A comprehensive search was undertaken across four major databases and was evaluated and assessed until June 2020.

RESULTS

A total of 16,104 patients were included in the study (7772 patients co-TBAD and 8352 un-TBAD). A significantly higher proportion of comorbidities were seen in co-TBAD patients compared with un-TBAD. Acute dissection was more frequent in the co-TBAD group (73.55% vs. 66.91%), while chronic dissection was more common in un-TBAD patients (33.8% vs. 70.73%). Postprocedure stroke was higher in co-TBAD (5.85% vs. 3.92%; p < .01), while postprocedural renal failure was higher in un-TBAD patients (7.23 vs. 11.38%; p < .01). No difference was observed in in-hospital mortality however the 30 days mortality was higher in the co-TBAD group. One-year survival was higher in the uncomplicated group but this difference was not observed in the 5-year survival.

CONCLUSION

In our analysis we can appreciate that despite significantly higher comorbidities in the co-TBAD cohort, there was no difference in in-hospital mortality between the two groups and the 5-year survival did not have any difference.

Is TEVAR really needed for uncomplicated type B aortic dissection?

Thoracic endovascular aortic repair (TEVAR) has quickly become the mainstay of treatment for acute aortic dissection, in particular cases of acute complicated Stanford Type B dissection (co-TBAD). Necessarily, TEVAR carries with it the risk of postoperative complications, including stroke and renal failure. As a result, the management of patients with uncomplicated type B aortic dissection (un-TBAD), which is generally accepted as being less severe, is safely managed via optimal medical therapy (OMT) alone. However, despite OMT, patients with un-TBAD are at substantial risk of severe disease progression requiring delayed intervention. The cost-benefit ratio associated with TEVAR for un-TBAD is therefore of key interest. Howard and colleagues produced a fascinating systematic review and meta-analysis investigating the clinical outcomes of TEVAR for complicated and uncomplicated TBAD. Their data suggest that there is no significant difference in in-hospital mortality or 5-year survival between TEVAR for un-TBAD and co-TBAD, although the 30-day mortality rate appeared to be higher in the co-TBAD cohort. Patients with co-TBAD appeared to also be at a higher risk of postoperative stroke and TEVAR endoleak, while un-TBAD patients were at a higher risk of postoperative renal failure. Further prospective research into these relationships is recommended to fully elucidate the comparative efficacies of TEVAR for un-TBAD and co-TBAD.

Predictors of adverse events in uncomplicated type B aortic dissection: a systematic review with meta-analysis

INTRODUCTION

Thoracic Endovascular Aortic Repair (TEVAR) has been selectively used for uncomplicated acute type B Aortic Dissection (TBAD); however, not all cases will benefit from TEVAR. A search for high risk clinical and radiographic predictors for complications is ongoing. This systematic review and meta-analysis aimed to identify predictors of major adverse events during follow-up of uncomplicated TBAD, in order to identify who might benefit from elective TEVAR.

EVIDENCE ACQUISITION

A systematic review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) statement.

EVIDENCE SYNTHESIS

16 studies were included in a qualitative synthesis and 10 in the meta-analysis. Several risk factors associated to major adverse events have been described, including (1) aortic diameter ≥40 mm, (2) greater false lumen diameter (>22mm), (3) patent false lumen, (4) primary entry tear > 10mm, and (5) greater number of false lumen vessels origin. Quantitative synthesis identified an aortic diameter ≥40 mm significantly associated with major adverse events (HR=3.56; p<0.00001). Reporting of false lumen status, aortic diameters and growth, and demographic data was not always congruent with the most recent recommendations by Society for Vascular Surgery and Society of Thoracic Surgeons, published in 2020.

CONCLUSIONS

Acute and subacute patients with uncomplicated TBAD presenting with an aortic diameter ≥ 40 mm and solely treated with BMT have an increased hazard of developing major adverse events (HR), making them potential candidates for TEVAR. Remaining risk factors analysed have weaker evidence.

A more proximal landing zone is preferred for thoracic endovascular repair of acute type B aortic dissections

OBJECTIVES

Thoracic endovascular aortic repair (TEVAR) has become first line therapy for complicated acute type B aortic dissection (aTBAD). However, the strategy for optimal proximal landing zone remains to be determined. We compared early outcomes and late aortic-related adverse events in patients undergoing TEVAR for complicated aTBAD with endograft deployment in proximal landing zone 2 versus 3.

METHODS

We performed a retrospective chart review of adult patients undergoing TEVAR for complicated aTBAD within 6 weeks of diagnosis from 1/2008 to 12/2018. We excluded patients with connective tissue disorders and prior type A repair. Patients were divided into landing zone 2 TEVAR (Z2T) and zone 3 TEVAR (Z3T) groups. Z2 patients were divided between left subclavian artery (LSA) revascularization (Z2R) versus LSA coverage without revascularization (Z2C). Groups were compared for need for aortic re-intervention within 36 months of initial admission and freedom from aortic related adverse events and mortality (AREM), defined as need for aortic re-intervention, aortic-related death or rupture.

RESULTS

Eighty-three patients underwent TEVAR for complicated aTBAD within a mean of 4.1±7.8 days. 89.5% of patients had less than 2 cm of healthy proximal descending thoracic aorta. Landing zone was Z3T in 35 patients and 48 underwent Z2T: 10 Z2C and 38 Z2R. There were no differences between Z2T and Z3T in time from diagnosis to TEVAR, demographics, comorbidities and diameter aortic measurements. 30-day survival was 87.8%: 89.5% for Z2R, 88.6% for Z3 and 80.0 % for Z2C (p=0.610). Post-operative spinal cord ischemia rate was 3.7%: 2.7 % for Z2R, 0% for Z3T and 20.0% for Z2C (p=0.012). Post-operative thoracic aortic rupture was 2.2% in Z2 and 0 in Z3. Need for aortic re-intervention at 36 months post-TEVAR was lower for Z2T (10.4%) vs. Z3T (31.4%), p=0.025. Freedom from AREM at 36 months was higher in Z2T vs. Z3T - 87.5% vs. 68.6%, p= 0.048. Freedom from proximal re-intervention was higher in Z2T (95.8%) compared to Z3T (80.0%), p=0.019. Z3T deployment was predictive for AREM (OR:3.648,95%CI:1.161-11.465,p=0.027) and need for proximal re-intervention (OR: 5.542,95%CI:1.062-28.927,p=0.042).

CONCLUSION

Most patients with aTBAD have less than 2 cm of proximal healthy descending thoracic aorta. In patients treated for complicated aTBAD, zone 2 TEVAR is associated with a lower need for aortic re-intervention and aortic-related adverse events than zone 3 TEVAR. Patients may benefit from a more aggressive proximal landing zone with similar perioperative morbidity when zone 2 TEVAR is done with LSA revascularization.

National trends in repair for type B aortic dissection

Background

Thoracic endovascular aortic repair (TEVAR) first gained in popularity for repair of type B aortic dissections (TBADs) in the early 2000's. We aimed to describe patients undergoing open repair, TEVAR, and no repair and analyze factors associated with repair within 14 days of presentation in the contemporary era.

Methods

We used the MarketScan database to find patients with TBAD between 2014 and 2017. To assess factors associated with early repair, univariable, and multivariable log‐binomial regression were used.

Results

There were 2613 patients admitted with TBAD between 2014 and 2017 across the United States, of whom 38.4% underwent repair within 14 days of admission (25.3% open repair and 13.1% TEVAR). The incidence of repair within 14 days decreased over the study period (43% of the study cohort in 2014 to 26.4% in 2017) primarily due to a decrease in open repairs from 30.8% of patients in 2014 to 12.5% in 2017. In multivariable analysis, older age, Middle Atlantic location, diabetes mellitus, insulin use, antiplatelet use, and more recent year were associated with lower likelihood of early repair; male sex, peripheral vascular disease, and the presence of extremity ischemia, rupture, shock, and acidosis were associated with higher likelihood of repair.

Conclusions

Overall, repair of TBAD within 14 days of presentation declined from 2014 to 2017, with a steady rate of TEVAR but declining rate of open repairs. Further investigation into provider‐ and hospital‐specific factors as they relate to likelihood of repair is needed.

Predictors of 30-day readmission and resource utilization after thoracic endovascular aortic repair

OBJECTIVES

The introduction and expansion of thoracic endovascular aortic repair (TEVAR) have revolutionized the treatment of a variety of thoracic aortic diseases. We sought to evaluate the incidence, causes, predictors and costs associated with 30-day readmission after TEVAR in a nationally representative cohort.

METHODS

Adult patients undergoing isolated TEVAR were identified in the National Readmissions Database from 2010 to 2014. Hospital costs were estimated by converting individual hospital charge data adjusted to 2014 consumer price indices. Multivariable logistic regression was utilized to determine hospital- and patient-level factors associated with readmissions.

RESULTS

A total of 24 983 TEVARs were noted during the study period; the average age of the patients was 65 ± 16 years; 40% were women. The most common indication was an intact thoracic aneurysm (43.5%), followed by aortic dissection (30.5%). The average cost of the index admission was $63 644 ± $52 312; the average hospital stay was 11 ± 14 days; the index mortality rate was 6.7%. Readmissions within 30 days occurred in 17.4% of patients. Indications for readmission were varied; the most common aetiologies were cardiac (17.8%), infectious (16.0%) and pulmonary (12.1%). On multivariable analysis, the strongest predictor of readmission was the diagnosis, with a ruptured thoraco-abdominal aneurysm having the highest readmission burden (adjusted odds ratio 2.23, 1.17-4.24; P = 0.015). Notably, hospital volume did not predict index hospital length of stay, costs or 30-day readmissions (all P > 0.10).

CONCLUSIONS

Annual TEVAR volume was not associated with any of the outcomes assessed. Rather, indication for TEVAR was the strongest predictor for many outcomes. As TEVAR becomes increasingly utilized, a focus on cardiac and vascular diseases may reduce readmissions and improve quality of care.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Using Machine Learning to Predict Five-Year Reintervention Risk in Type B Aortic Dissection Patients After Thoracic Endovascular Aortic Repair

Purpose: Type B aortic dissection (TBAD) is a high-risk disease, commonly treated with thoracic endovascular aortic repair (TEVAR). However, for the long-term follow-up, it is associated with a high 5-year reintervention rate for patients after TEVAR. There is no accurate definition of prognostic risk factors for TBAD in medical guidelines, and there is no scientific judgment standard for patients’ quality of life or survival outcome in the next five years in clinical practice. A large amount of medical data features makes prognostic analysis difficult. However, machine learning (ML) permits lots of objective data features to be considered for clinical risk stratification and patient management. We aimed to predict the 5-year prognosis in TBAD after TEVAR by Ml, based on baseline, stent characteristics and computed tomography angiography (CTA) imaging data, and provided a certain degree of scientific basis for prognostic risk score and stratification in medical guidelines. Materials and Methods: Dataset we recorded was obtained from 172 TBAD patients undergoing TEVAR. Totally 40 features were recorded, including 14 baseline, 5 stent characteristics and 21 CTA imaging data. Information gain (IG) was used to select features highly associated with adverse outcome. Then, the Gradient Boost classifier was trained using grid search and stratified 5-fold cross-validation, and Its predictive performance was evaluated by the area under the curve (AUC) in the receiver operating characteristic (ROC). Results: Totally 60 patients underwent reintervention during follow-up. Combing 24 features selected by IG, ML model predicted prognosis well in TBAD after TEVAR, with an AUC of 0.816 and a 95% confidence interval of 0.797 to 0.837. Reintervention rate of prediction was slightly higher than the actual (48.2% vs. 34.8%). Conclusion: Machine learning, which combined with baseline, stent characteristics and CTA imaging data for personalized risk computations, effectively predicted reintervention risk in TBAD patients after TEVAR in 5-year follow-up. The model could be used to efficiently assist the clinical management of TBAD patients and prompt high-risk factors.

A multicenter study of emergency endovascular repair of the thoracic aorta: Indications and outcomes

OBJECTIVE

Endovascular techniques have become an essential tool for the treatment of descending thoracic aortic disease (thoracic endovascular aneurysm repair [TEVAR]). The aim is to analyze the indications and outcomes of emergency TEVAR at national level in relation to elective surgery.

STUDY DESIGN AND SCOPE

A retrospective multicenter registry of patients with descending thoracic aortic disease treated on an emergency basis using endovascular techniques between 2012-2016, in 11 clinical units.

PATIENTS, INCLUSION CRITERIA

1) Ruptured descending thoracic aortic aneurysms (RTAA); 2) Blunt traumatic thoracic aortic injury (TAI); and 3) Complicated acute type B aortic dissections (TBADc).

PRIMARY VARIABLES

Patient mortality, survival and reoperation rate.

SECONDARY VARIABLES

Demographic data, cardiovascular risk factors, specific data by indication, technical resources and postoperative complications.

RESULTS

A total of 135 urgent TEVARs were included (111 men, mean age 60.4 ± 16.3 years): 43 ruptured thoracic aortic aneurysms (31.9%), 54 type B dissections (40%) and 32 traumatic aortic injuries (23.7%), and other etiologies 4.4%. The overall mortality rate at 30 days was 18.5%, and proved higher in the RTAA group (27.9%). The mean actuarial survival rate was 67 ± 6% at 5 years. The postoperative stroke rate was 5.2%, and the paraplegia rate was 5.9%. Aortic reoperations proved necessary in 12 patients (9%).

CONCLUSIONS

Emergency descending thoracic aortic diseases can be treated by endovascular techniques with optimal results and low morbidity and mortality - though the figures are slightly higher than in elective cases. This registry provides, for the first time, real information on the daily clinical practice of emergency TEVAR in Spain.

Predictors of Adherence to Anti-Impulse Therapy among Patients Treated for Acute Type-B Aortic Dissections

BACKGROUND

Medical management remains the mainstay of treatment for patients who present with acute Type-B aortic dissections (TBAD). However, it is unclear whether patients maintain adherence to their anti-impulse therapy medication regimen following hospital discharge. This study was designed to evaluate rates and predictors of medication adherence among insured patients treated for acute TBAD.

METHODS

We used the Truven MarketScan database to identify US patients who presented with an acute TBAD between 2008 to 2017. Patients with continuous health insurance (Commercial or Medicare Part C) for at least 12 months after TBAD diagnosis were stratified by whether they underwent open surgical repair (OPEN), thoracic endovascular aortic repair (TEVAR), or only medication management (MED). Prescriptions for anti-impulse therapy medications were captured and adherence was defined by the medication possession ratio as > 80% fill rate over the follow-up period. Mixed-effects logistic regression models were used to identify predictors for medication adherence.

RESULTS

A total of 6,702 patients were identified that underwent treatment for TBAD (3% TEVAR, 9% OPEN, & 74% MED), whereas 14% received no intervention. The overall mean (±SD) rate of adherence to anti-impulse therapy was 72.6% ( ± 26), and varied based on type of TBAD intervention (73.4% TEVAR, 74.4% OPEN, & 72.4% MED). The majority of patients across all treatment groups were prescribed ≥ 2 agents, with beta-blockers and diuretics being the most common medication classes. The odds of adherence to anti-impulse therapy were significantly lower for patients who were female (OR: 0.93; 95%CI:0.85-0.99; P = 0.03), aged < 45 years (OR: 0.81; 95%CI:0.69-0.96; P < 0.001), nonadherent on preexisting therapy (OR: 0.81; 95%CI: 0.73-0.89; P < 0.001), and when medications were obtained in less than a 90 days supply from retail pharmacies.

CONCLUSIONS

Nearly a quarter of patients were nonadherent with anti-impulse therapy prescribed following an acute TBAD, which was more likely among younger female patients not adherent before their event. Adherence was improved among patients who received their medications by mail and when a > 90 days supply was prescribed. These findings may be used by quality improvement initiatives to improve medication adherence following TBAD and help prevent further complications.

Thoracic Endovascular Aortic Repair With Additional Distal Bare Stents in Type B Aortic Dissection Does Not Prevent Long-Term Aneurysmal Degeneration

PURPOSE

TEVAR (thoracic endovascular aortic repair) + PETTICOAT (Provisional ExTension to Induce COmplete ATtachment) technique has been selectively employed since 2005 at our institution during endovascular treatment of type B aortic dissection (TBD). The aim of this study is to evaluate the long-term (>5 years) clinical results and the evolution of aortic volume.

MATERIALS AND METHODS

All the patients receiving an endovascular treatment for TBD with the PETTICOAT technique were collected in a prospectively maintained database and follow-up computed tomography scan were retrospectively analyzed. Study endpoints included short- and long-term clinical success (absence of need for reintervention) and any major adverse event. The volumes of thoracic and abdominal aorta at long-term follow-up were also analyzed.

RESULTS

Twenty-eight patients received a TEVAR + PETTICOAT and were followed up (median follow-up 85 months). Primary 30-day clinical success rate was 82% with an adverse event rate of 31%; 4 type I endoleak and 1 retrograde dissection were recorded. Secondary mid-term clinical success was 96% while the long-term clinical success rate was 79%. Six cases (21%) received either an open repair or an endovascular repair for a significant distal aortic enlargement at follow-up. With regards to volumetric analysis, an increase of overall (thoracic and abdominal) aortic volume was observed in 8 cases mainly related to an increase (mean: +31%) of the abdominal volume that was observed in 11 cases.

CONCLUSIONS

PETTICOAT technique does not protect from long-term significant aneurysmal degeneration that may require aortic open or endovascular reinterventions. Aortic growth occurs mainly in the bare-stented aorta and thus, life-long surveillance is advisable in these patients.

Systematic review and meta-analysis of endovascular interventions for Stanford type A aortic dissection

OBJECTIVE

The standard surgical approach to Stanford type A aortic dissection is open repair. However, up to one in four patients will be declined surgery because of prohibitive risk. Patients who are treated nonoperatively have an unacceptably high mortality. Endovascular repair of the ascending aorta is emerging as an alternative treatment for a select group of patients. The reported rates of technical success, mortality, stroke, and reintervention have varied. The objective of the study was to systematically report outcomes for acute type A dissections repaired using an endovascular approach.

METHODS

The systematic review and meta-analysis was conducted in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. We performed online literature database searches through April 2020. The demographic and procedural characteristics of the individual studies were tabulated. Data on technical success, short-term mortality, stroke, and reintervention were extracted and underwent meta-analysis using a random effects model.

RESULTS

Fourteen studies with 80 cases of aortic dissection (55 acute and 25 subacute) were included in the final analysis. A wide variation was found in technique and device design across the studies. The outcomes rates were estimated at 17% (95% confidence interval [CI], 10%-26%) for mortality, 15% (95% CI, 8%-23%) for technical failure, 11% (95% CI, 6%-19%) for stroke and 18% (95% CI, 9%-31%) for reintervention. The mean Downs and Black quality assessment score was 13.9 ± 3.2.

CONCLUSION

The technique for endovascular repair of type A aortic dissection is feasible and reproducible. The results of our meta-analysis demonstrate an acceptable safety profile for inoperable patients who otherwise would have an extremely poor prognosis. Data from clinical trials are required before the technique can be introduced into routine clinical practice.

TEVAR Following FET: Current Outcomes of Rendezvous Procedures in Clinical Practice

BACKGROUND

 The treatment of extensive thoracic/thoracoabdominal aortic pathologies with arch involvement remains a challenging task in aortic surgery. The introduction of the frozen elephant trunk (FET) technique offered a link between open surgery and thoracic endovascular aortic repair (TEVAR). Despite a decade of experience, data on the complementary use of these techniques are scant. The aim of this study was to evaluate TEVAR following FET in clinical reality.

METHODS

 Between November 2006 and June 2018, 20 patients (9 females; median age of 69 years) underwent endovascular second-stage completion after FET. The clinical outcomes, technical feasibility, and morphological findings were analyzed retrospectively.

RESULTS

 Eleven of the 20 interventions were intended "rendezvous procedures" in a multistage approach; 4 were elective reinterventions, and 5 were emergency complication repairs. The median interval between FET and TEVAR was 231 days (11 days-7.4 years). The technical success rate was 100%. During a median follow-up (FU) period of 58.3 months, the overall survival rate was 95%, with one in-hospital death. Neurological complications occurred in three cases (spinal cord injury: n = 1; stroke: n = 2). Computed tomography angiography showed overall regression in the median diameter of the proximal descending aorta (from 57 to 48.5 mm).

CONCLUSION

 TEVAR as a second-stage intervention after FET is a feasible option, with satisfactory results at medium-term FU. In extensive thoracoabdominal aortic disease without proximal landing zones, the complementary use of both techniques in a multistage approach should be considered.

Ten-Year Clinical Characteristics and Early Outcomes of Type B Aortic Dissection Patients With Thoracic Endovascular Aortic Repair

OBJECTIVE/BACKGROUND

This study examined the 10-year hospitalization characteristics, economic patterns and early clinical outcomes of type B aortic dissection (TBAD) patients that underwent thoracic endovascular aortic repair (TEVAR) in one high-volume hospital in China.

METHODS

We performed a population-based retrospective analysis based on electronic medical record system data provided by Zhongshan Hospital Fudan University from 2009 to 2018.

RESULTS

We identified 1,367 cases of TBAD patients with TEVAR over the past decade. The total incidence of in-hospital complications was 7.6% (104 of 1,367), among which acute kidney injury (AKI) had the highest incidence (3.1%, 42 of 1,367). Aortic-related reintervention was performed in 7 patients (0.5%). The overall aortic-related in-hospital mortality rate was 2.7% (37 of 1,367) and had no significant time-varying trend (P = 0.2). Among these, 27% of in-hospital deaths were caused by retrograde type A dissection (RTAD). Chronic TBAD had a higher risk of in-hospital death versus acute TBAD, with a risk ratio of 2.69 (95% confidence interval [CI]: 1.19-6.09). Patients with hypertension (risk ratio 4.63, 95% CI: 1.38, 15.54) also had a higher in-hospital death risk. These 2 factors were also the predictive factors for the composite endpoint of in-hospital adverse events (risk ratio 2.17, 95% CI: 1.43, 3.29 and risk ratio 4.83, 95% CI: 1.90, 12.28, respectively), in addition to Marfan syndrome (risk ratio 4.05, 95% CI: 1.61, 10.19). The average length of hospitalization significantly declined during the past decade (annual percentage change -6.3%, 95% CI -8.2 to -4.3), and the stent-grafts (SGs) cost was the main expenditure of the total hospitalization costs.

CONCLUSION

Our study showed a favorable early outcome of TEVAR over the past decade. Greater attention should be paid to certain risk factors in order to reduce the in-hospital adverse events. SG expenditure is still the primary economic burden on Chinese TBAD patients.

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

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

Endograft exclusion of the false lumen restores local hemodynamics in a model of type B aortic dissection

OBJECTIVE

Endovascular intervention in uncomplicated type B dissection has not been shown conclusively to confer benefit on patients. The hemodynamic effect of primary entry tear coverage is not known. Endovascular stent grafts were deployed in a model of aortic dissection with multiple fenestrations to study these effects. It is hypothesized that endograft deployment will lead to restoration of parabolic true lumen flow as well as elimination of false lumen flow and transluminal jets and vortices locally while maintaining distal false lumen canalization.

METHODS

Thoracic stent grafts were placed in silicone models of aortic dissection with a compliant and mobile intimal flap and installed in a flow loop. Pulsatile fluid flow was established with a custom positive displacement pump, and the models were imaged by four-dimensional flow magnetic resonance imaging. Full flow fields were acquired in the models, and velocities were extracted to calculate flow rates, reverse flow indices, and oscillatory shear index, the last two of which are measures of stagnant and disturbed flows.

RESULTS

Complete obliteration of the false lumen was achieved in grafted aorta, with normal parabolic flow profiles in the true lumen (maximal velocity, 30.4 ± 8.4 cm/s). A blind false lumen pouch was created distal to this with low-velocity (5.8 ± 2.7 cm/s) and highly reversed (27.9% ± 13.9% reverse flow index) flows. In distal free false lumen segments, flows were comparable to ungrafted conditions with maximal velocities on the order of 7.0 ± 2.1 cm/s. Visualization studies revealed forward flow in these regions with left-handed vortices from true to false lumen. Shear calculations in free false lumen regions demonstrated reduced oscillatory shear index.

CONCLUSIONS

Per the initial hypothesis, endovascular grafting improved true lumen hemodynamics in the grafted region. Just distally, a prothrombotic flow regimen was noted in the false lumen, yet free false lumen distal to this remained canalized. Clinically, this suggests a need for advancing endovascular intervention beyond sole entry tear coverage to prevent further false lumen canalization through uncovered fenestrations.

Open Surgical Repair of Abdominal Aortic Aneurysms Maintains a Pivotal Role in the Endovascular Era

Since the advent of endovascular aortic repair (EVAR) nearly three decades ago, there has been a paradigm shift in the treatment of the abdominal aortic aneurysm (AAA) to favor EVAR due to its reduced operative mortality, less invasive nature, and faster recovery times. However, more recently there has been an accumulation of data from large meta-analyses and randomized clinical trials revealing that EVAR has no survival benefit after approximately 2 years and is associated with substantially higher rates of reintervention and aneurysm rupture in the long term. These findings call into question the durability of EVAR compared with open aortic repair and emphasize the need for surgeons to remain competent with open aortic surgery in the modern era. This article will provide comprehensive review of a large body of literature comparing endovascular repair to open aortic surgery for the management of AAAs, and it will offer an overview of the open surgical repair technique for AAAs.

Aortic remodelling after thoracic endovascular aortic repair in acute and chronic type B aortic dissections

OBJECTIVES

Type B aortic dissections are routinely treated with thoracic endovascular aortic repair (TEVAR). The timing for TEVAR remains controversial and might have an impact on the remodelling capacity of the aorta. This study analyses and compares aortic remodelling in acute (ABD) and chronic (CBD) type B aortic dissections after TEVAR.

METHODS

This retrospective study analysed the preoperative, postoperative and at least 1-year follow-up computed tomography of 53 TEVAR patients (36 ABD, 17 CBD) at a single institution between May 2005 and May 2016. The volumes of aortic lumen (AL), true lumen, false lumen (FL) and perfused FL were measured at the stent graft level (A), from the stent graft to the coeliac trunk (B) and from the coeliac trunk to the bifurcation (C). The absolute volumes, normalized volume changes and FL thrombosis rate of ABD and CBD patients were compared.

RESULTS

Absolute AL and FL of segment A were significantly larger in CBD patients compared to ABD patients preoperatively (AL: 354 ± 68 vs 255 ± 51 ml, P = 0.023, FL: 253 ± 56 vs 183 ± 35 ml, P = 0.028) until last follow-up (AL: 462 ± 52 vs 246 ± 52 ml, P = 0.003, FL: 268 ± 202 vs 91 ± 31 ml, P = 0.004). The true lumen in segment A increased more in ABD than in CBD patients preoperatively to postoperatively (112% vs 36% P < 0.001) and within the first year postoperatively (171% vs 80% P < 0.001). FL in segment A decreased more in ABD compared to CBD patients within the first year (-42% vs -13% P < 0.001) and thereafter (-50% vs +6% P = 0.002). In segments B and C, the FL thrombosis rate was higher in ABD than in CBD patients at all time points and significantly higher in segment A after the first year (91% vs 98% P = 0.035).

CONCLUSIONS

Aortic remodelling after TEVAR is significantly different in acute and chronic dissection patients. TEVAR promotes aortic remodelling in both acute and chronic dissections in terms of true lumen increase at stent graft level. Nevertheless, significant AL reduction by FL shrinkage is primarily found in ABD.

Important issues regarding planning and sizing for emergent TEVAR

In the past decades, treatment of acute thoracic aortic syndrome underwent drastic changes with a central role for thoracic endovascular aortic repair (TEVAR). One of the essential factors in the success of TEVAR is accurate sizing of the endograft, as both under- and oversizing can lead to suboptimal results and disastrous complications. The aim of this review was to give an overview of issues regarding endograft sizing in emergent TEVAR. Sizing of the endograft can be complicated by specific factors related to the underlying disease. For instance, different types of the acute thoracic aortic syndrome, i.e. blunt thoracic injury, thoracic aortic aneurysm or dissection with concomitant rupture are associated with hemorrhagic shock and the need for resuscitation, which leads to profound changes in diameter of the thoracic aorta. These diameter changes should be taken into account during endograft sizing. Measuring the thoracic aorta based on the admission CTA can lead to inaccurate sizing, even if proper centerline-based measurements are performed. The use of real-time imaging, in particular intravascular ultrasound (IVUS), has been shown to provide more accurate endograft sizing in acute thoracic aortic syndromes, especially if associated with hypovolemia. Future research should provide additional data on the exact role of different intra-operative imaging modalities (e.g. IVUS, transesophageal echocardiography [TEE], three dimensional CTA) on endograft sizing and long-term outcomes to ultimately improve patient outcome.

Predictive Factors of Operative Need in Medically Managed Type B Aortic Dissections

BACKGROUND

Aneurysmal degeneration of medically managed type B aortic dissection (TBAD) can be a life-threatening condition. Preventive thoracic endovascular aorta repair (TEVAR) in patients at risk could potentially be beneficial. The aim of this study was to examine the predictors for late aneurysmal dilatation after TBAD.

METHODS

A retrospective study was conducted on 82 patients with medically managed acute TBAD for a minimum of 14 days. Relevant demographic, biochemical, and radiographic variables at presentation were studied. The aortic dissection risk calculator tool developed by Sailer et al., predicting the risk of adverse events after aortic dissection based on demographic and radiographic variables at presentation, was tested retrospectively.

RESULTS

With a median follow-up of 36 months (range 13-68), 25 (30.5%) patients underwent surgery (92% TEVAR). A larger initial aortic and false lumen diameter as well as a greater distal extension of the dissection was associated with higher need for surgery (respectively, P = 0.003, P = 0.004, and P = 0.001). We observed higher growth rates of maximum aortic diameter in patients with a greater distal extension of the dissection, larger false lumen diameters and false lumen outflow, and entry tears located at the inner aortic arch (respectively, P = 0.001, P = 0.005, P = 0.001 and P = 0.014). No significant correlations could be found for the risks provided by the calculator tool.

CONCLUSIONS

The initial maximum aortic diameter of TBAD is a key predictor for aortic growth. Furthermore, the distal extension of the dissection also seems to play an important role in late aneurysmal degeneration. However, we were not able to confirm the added value of the risk calculator tool in our study group.

One-Year Single-Center Results of the Multilayer Flow Modulator Stents for the Treatment of Type B Aortic Dissection

Purpose

To report a single-center series of patients with type B aortic dissection treated with the Multilayer Flow Modulator (MFM).

Materials and Methods

Over a 36-month period, 23 patients (median age 53 years; 20 men) with complicated type B aortic dissections (2 acute, 5 subacute, and 16 chronic) were treated with the MFM. Primary endpoints of rupture or dissection-related death, overall mortality, and reintervention were evaluated using the Kaplan-Meier method; estimates for freedom from the endpoints are reported with the 95% confidence interval (CI). Secondary outcomes included technical success, adverse events, and aortic remodeling. Clinical and imaging data were collected preoperatively, directly postoperatively, and annually to 36 months for analysis using computational fluid dynamics (CFD).

Results

Initial technical success was 91.3%. The estimates of the endpoints at 12 months were 100% for freedom from rupture or aortic-related death, 95.7% for freedom from overall mortality, and 91.3% for freedom from reintervention. No device-related neurological or systemic complications occurred, and no additional reinterventions were needed during follow-up. A total of 144 branches overstented by the MFM remained patent. Morphologic analysis of the aortic dissection showed progressive true lumen volume increase (75.9%, p<0.001) with concomitant false lumen volume decrease (42.8%, p<0.001); the CFD analyses showed increased laminar flow.

Conclusion

In the current series, the MFM provided a safe and feasible treatment option for complicated acute, subacute, and chronic type B aortic dissections, with high technical success, low mortality, and active aortic remodeling. Further studies should elucidate the long-term safety of the MFM and its effectiveness in a larger patient cohort.

Clinical and Morphologic Outcomes of Endovascular Repair for Subacute and Chronic Type B Aortic Dissection

BACKGROUND

The objective of the study was to assess long-term remodeling, survival, and reintervention outcomes after thoracic endovascular aortic repair (TEVAR) for subacute and chronic type B aortic dissection (TBAD).

METHODS

All patients who underwent TEVAR for subacute or chronic TBAD at a tertiary referral center between 1999 and 2015 were included in this cohort study. The primary outcome was aortic remodeling, and secondary outcomes included survival, rate of major complications, and reinterventions.

RESULTS

Fifty patients were included, with mean age of 62.4 years, 10 (20%) DeBakey type IIIA and 40 (80%) DeBakey type IIIB dissection; 45 standard TEVAR, 2 branched TEVAR, 3 TEVAR combined with fenestrated or branched EVAR. Indication for TEVAR was intact (n = 40) or ruptured (n = 1) postdissection aneurysm, hypoperfusion (n = 4), treatment-refractory pain (n = 2), or a combination (n = 3). Mean clinical follow-up was 76 months, and median radiological follow-up was 46 months. Thirty-day survival was 96%, stroke 4%, renal failure 0%, paraplegia 0%. Three- and five-year survival was 92% (95% confidence interval (CI) [79; 97]) and 77% (95% CI [61; 87]), respectively. Of 19 late deaths, 6 were confirmed aorta related. Five-year freedom from reintervention was 69% (95% CI [53-80]). Distal stent graft extension due to aortic dilatation composed most reinterventions. Mean maximal aortic diameter was 58.7 mm preoperatively and 51.9 mm on last follow-up (P = 0.003). On thoracic level, true lumen expanded (+10.0 mm, 95% CI [6.4; 13.6]) (P < 0.001) and false lumen decreased (-11.9 mm, 95% CI [-15.2; -8.5]) (P < 0.001) from baseline to the last computed tomography. In the abdominal aorta, true lumen diameter change was +3.1 mm (95% CI [1.4; 4.8]) (P = 0.001); false lumen diameter change was +1.0 mm (95% CI [-1.8; 3.8]) (P = 0.464).

CONCLUSIONS

TEVAR for subacute and chronic TBAD results in favorable remodeling of the thoracic but not the abdominal aorta. Five-year survival is almost 80%, but late aortic deaths still occur. Aortic dilatation distal to the treated segment requiring reintervention is common, emphasizing the importance of follow-up.

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.

The Influence of Aortic Wall Elasticity on the False Lumen in Aortic Dissection: An In Vitro Study

BACKGROUND

Hemodynamics, dissection morphology, and aortic wall elasticity have a major influence on the pressure in the false lumen. In contrast to aortic wall elasticity, the influence of hemodynamics and dissection morphology have been investigated often in multiple in vitro and ex vivo studies. The purpose of this study was to evaluate the influence of aortic wall elasticity on the diameter and pressure of the false lumen in aortic dissection.

METHODS

An artificial dissection was created in 3 ex vivo porcine aortas. The aorta models were consecutively positioned in a validated in vitro circulatory system with physiological pulsatile flow. Each model was imaged with ultrasound on 4 positions along the aorta and the dissection. At these 4 locations, pressure measurement was also performed in the true and false lumen with an arterial catheter. After baseline experiments, the aortic wall elasticity was adjusted with silicon and the experiments were repeated.

RESULTS

The aortic wall elasticity was decreased in all 3 models after siliconizing. In all 3 siliconized models, the diameters of the true and false lumen increased at proximal, mid, and distal location, while the mean arterial pressure did not significantly change.

CONCLUSIONS

In this in vitro study, we showed that aortic wall elasticity is an important parameter altering the false lumen. An aortic wall with reduced elasticity results in an increased false lumen diameter in the mid and distal part of the false lumen. These results can only be transferred to corresponding clinical situations to a limited extent.

Management of Uncomplicated Type B Aortic Dissection

Acute aortic dissection has an incidence of approximately half that of symptomatic abdominal and thoracic aneurysm of the aorta and more than twice the mortality of population-based controls. While urgent undelayed open surgery is the strategy of choice in proximal dissection, medical management has been the mainstay of treatment for uncomplicated distal or type B aortic dissection, but endovascular intervention is now considered a potential treatment option for all type B dissection due to its success in complicated cases. Endovascular repair can be technically demanding in aortic dissection, and timing of the repair can have a significant influence on anatomical and clinical outcome. Observational reports of feasibility and reasonable safety are flanked by only two randomised trials; the Acute Dissection Stent Grafting or Best Medical Treatment (ADSORB) trial demonstrated improved remodelling in acute dissection and the INvestigation of STEnt grafts in patients with type B Aortic Dissections (INSTEAD) trial showed better long-term survival in patients treated endovascularly in the subacute phase. Meta-analyses and other large clinical studies have demonstrated mixed results. Due to some risks associated endovascular repair and the requirement of specialist aortic care (which is not always available), a pragmatic approach for current management could involve high intensity serial imaging in the acute phase of a type B aortic dissection, thereby identifying complicated cases for early intervention and selection of patients at high risk of disease progression for deferred endovascular management in the subacute phase within 90 days.