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

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.

Extensive Aortic Dissection from Aortic Root to Iliac Artery

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Aortic dissection is a life-threatening medical emergency in patients with MFS.

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Stanford type B aortic dissection is observed in one third of MFS cases.

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Adequate cardiovascular surveillance can reduce the progression of aortic dilation.

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Clinicians must ensure compliance to medication despite hemodynamically stability.

Location of Reentry Tears Affects False Lumen Thrombosis in Aortic Dissection Following TEVAR

Purpose: To report a study that assesses the influence of the distance between the distal end of a thoracic stent-graft and the first reentry tear (SG-FRT) on the progression of false lumen (FL) thrombosis in patients who underwent thoracic endovascular aortic repair (TEVAR). Materials and Methods: Three patient-specific geometrical models were reconstructed from postoperative computed tomography scans. Two additional models were created by artificially changing the SG-FRT distance in patients 1 and 2. In all 5 models, computational fluid dynamics simulations coupled with thrombus formation modeling were performed at physiological flow conditions. Predicted FL thrombosis was compared to follow-up scans. Results: There was reduced false lumen flow and low time-averaged wall shear stress (TAWSS) in patients with large SG-FRT distances. Predicted thrombus formation and growth were consistent with follow-up scans for all patients. Reducing the SG-FRT distance by 30 mm in patient 1 increased the flow and time-averaged wall shear stress in the upper abdominal FL, reducing the thrombus volume by 9.6%. Increasing the SG-FRT distance in patient 2 resulted in faster thoracic thrombosis and increased total thrombus volume. Conclusion: The location of reentry tears can influence the progression of FL thrombosis following TEVAR. The more distal the reentry tear in the aorta the more likely it is that FL thrombosis will occur. Hence, the distal landing zone of the stent-graft should be chosen carefully to ensure a sufficient SG-FRT distance.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Improved Remodeling With TEVAR and Distal Bare-Metal Stent in Acute Complicated Type B Dissection

BACKGROUND

The ASSIST (A multicentre Study in Survivors of type B aortic dissection undergoing Stenting) study compared both 1-year outcomes and evolution of true and false lumen (eg, remodeling) in patients with complicated type B aortic dissection subjected to thoracic endovascular aortic repair (TEVAR) with distal true lumen scaffolding by self-expanding nitinol open stent in comparison with TEVAR alone.

METHODS

The ASSIST study was a multicenter prospective single-arm study comparing clinical and imaging data from 39 consecutive patients (59.4 ± 13 years of age) who received TEVAR and the JOTEC E-XL open stent with data from matched control subjects treated with TEVAR alone based on 1:1 propensity score matching. Clinical data were collected by an independent Contract Research Organization (CRO) and computed tomography images were subjected to blinded core-lab analysis.

RESULTS

There were no differences in baseline demographics, clinical profiles, morphological data, procedural details, and in-hospital and 1-year outcomes between groups. Differences emerged with regard to evolution of both true lumen distal to stent graft, false lumen over the entire length of dissection, and remodeling (P < .001). At 1 year, TEVAR with the E-XL stent revealed false lumen thrombosis at the level of celiac trunk in 53.8% vs 17.9% with TEVAR alone (P = .004). Kaplan-Meier survival analysis indicated favorable clinical outcomes with the additional E-XL stent.

CONCLUSIONS

TEVAR for acute complicated type B aortic dissection proved to be safe and promoted remodeling of the stent grafted thoracic aorta. Additional scaffolding of the true lumen distal to TEVAR with a self-expanding stent supported distal true lumen expansion, false lumen regression, and thrombosis, with evidence of improved distal remodeling at 1 year.

Long-term Results of Thoracic Endovascular Aortic Repair for Type B Aortic Dissection and Risk Factors for Survival

Purpose: To compare characteristics of acute, subacute, and chronic type B aortic dissection and their influence on long-term results of thoracic endovascular aortic repair (TEVAR). Materials and Methods: In a single-center, retrospective cohort study, 314 patients (median age 52 years; 244 men) with acute (n=165), subacute (n=115), or chronic (n=34) type B aortic dissection underwent TEVAR between January 2009 and December 2013. Patient demographics, risk factors, and imaging characteristics were compared among the groups. Univariable and multivariable Cox regression analyses were performed to identify any factors influencing survival. Results: The acute and subacute patients exhibited more complications at presentation than chronic patients. However, the chronic patients exhibited more aneurysmal dilatation (p<0.001) and true lumen collapse (p<0.001). Over a mean follow-up of 68.1±22.9 months (range 2–108), subacute patients showed a lower reintervention rate (3.6% vs 12.1% vs 12.1%, p=0.045), a lower major complication rate (14.4% vs 33.1% vs 27.3%, p=0.002), and better cumulative overall survival (p=0.03) than the acute and chronic groups, respectively. Furthermore, acute patients developed more stent-graft–induced distal erosion (p=0.017) and retrograde type A dissection (RTAD) (p=0.036), whereas chronic patients had less aortic remodeling in the stented segment (p<0.001), distal thoracic aorta (p<0.001), and abdominal aorta (p=0.047). Finally, multivariable analysis demonstrated age >52 years, visceral malperfusion, and RTAD as independent factors influencing overall survival; aneurysmal dilatation, rupture/impending rupture, and RTAD were independent factors influencing aorta-specific survival. Conclusion: Acute and subacute patients had increased risks of rupture and complications at presentation, whereas chronic patients had increased risks for aneurysmal dilatation. From a long-term perspective, the subacute phase might be an optimal time for TEVAR in cases of type B aortic dissection that do not need emergent interventions. The risk factors influencing survival should be identified, carefully managed, and possibly prevented.

Comparison of aortic remodelling after conservative treatment or thoracic endovascular repair in type B dissections

OBJECTIVES

Our aim was to compare aortic remodelling in type B dissections after thoracic endovascular aortic repair (TEVAR) or conservative treatment.

METHODS

We conducted a retrospective analysis of computed tomography (CT) data sets at dissection onset and at the last follow-up in a group with conservative (group A) and TEVAR treatment (group B). An additional analysis of the preoperative CT images was performed in patients from group A, who were converted to TEVAR during follow-up. Diameters and lengths of all aortic segments were measured and growth rates were calculated.

RESULTS

We included 74 patients: 50 patients in group A (follow-up time: 1625 ± 209 days) and 24 patients in group B (follow-up time: 554 ± 129 days). The mean aortic diameter growth rate was significantly higher in group A than in group B in the mid-descending aorta (A: +7 mm/year; B: -4 mm/year; P = 0.003). Length growth difference was only present in the abdominal aortic segment and was more pronounced in group A (+2 vs ±0 mm/year; P = 0.009). The conversion rate from conservative treatment to TEVAR was 36% (n = 18). A false lumen diameter of >22 mm at baseline was associated with a higher rate of conversion (P = 0.036). After conversion, the mean growth rate in the proximal descending and mid-descending aorta decreased from preoperative +11 and +18 mm/year to postoperative -9 and -14 mm/year, respectively (P < 0.001).

CONCLUSIONS

In acute type B dissections, TEVAR stops aortic enlargement in the thoracic aorta, but promotes distal dilatation compared to the conservative treatment group. After conversion to TEVAR in conservatively pretreated chronic type B dissections, a more pronounced diameter decrease in the descending aorta was observed than in patients treated in the acute phase.

Smoking history increases the risk of long-term mortality after thoracic endovascular aortic repair in patients with an uncomplicated type B dissection

Background:

The preferred treatment for uncomplicated type B dissection (thoracic endovascular aortic repair [TEVAR] or medical) is still under debate. Since 2001, our center has performed TEVAR for uncomplicated type B dissection. Based on our data, 5- and 10-year survival rates among patients with uncomplicated type B dissection after TEVAR were 96.5% and 83.0%, respectively. We, therefore, believe that TEVAR is preferable for uncomplicated type B dissections. This study analyzed the impact of a pre-operative smoking history on long-term survival after TEVAR in patients with uncomplicated type B dissections.

Methods:

From May 2001 to December 2013, data from 751 patients with type B dissections were collected and analyzed. Patients were divided into two groups (337 smoking patients and 414 non-smoking patients). The Kaplan-Meier method and log-rank test were used to compare survival curves of the two groups. Multivariable analyses using the Cox proportional hazards model were used to estimate the effects of smoking on survival rates.

Results:

The 5- and 10-year survival rates of non-smokers were 97.6% (95% confidence interval [CI], 96.0%–99.2%) and 87.0% (95% CI, 81.6%–92.7%), respectively, and 94.9% (95% CI, 92.2%–97.7%) and 73.8% (95% CI, 62.3%–87.5%) for smokers, respectively (Log-rank test, P = 0.006). Multivariable analyses showed that smoking increased the risk of death during follow-up, 2.1-fold when compared to non-smokers (P = 0.039).

Conclusion:

A pre-operative smoking history increases long-term mortality rates after TEVAR in patients with uncomplicated type B dissections.

Total arch repair with frozen elephant trunk using the “zone 0 arch repair” strategy for type A acute aortic dissection

OBJECTIVE

The aim of this study was to investigate the effect of frozen elephant trunk deployment from the zone 0 aorta to the descending aorta on early and midterm postoperative results in patients with acute type A aortic dissection.

METHODS

Between October 2014 and April 2018, 108 patients underwent a combined strategy of frozen elephant trunk deployment, ascending aortic replacement, and arch vessel reconstruction ("zone 0 arch repair" strategy) for acute type A aortic dissection (excluding DeBakey type II). Of the 108 patients, 32 (29.6%) had primary tears of the aortic arch or descending aorta.

RESULTS

The 30-day mortality rate was 2.8% (3 patients), and in-hospital mortality rate was 6.5% (7 patients). New-onset permanent neurologic dysfunction and spinal cord injury occurred in 3.7% and 0% of patients, respectively. Five of the 101 survivors underwent thoracic endovascular aortic repair during hospitalization (2 for rapid false lumen enlargement; 3 for true lumen stenosis). The overall survival was 89.8%, 88.1%, and 88.1% at 1, 2, and 3 years, respectively. The cumulative incidence of distal aortic reintervention was 5.8%, 9.1%, and 9.1% at 1, 2, and 3 years, respectively. Two patients underwent thoracic endovascular aortic repair for distal aortic enlargement after discharge.

CONCLUSIONS

The use of the "zone 0 arch repair" strategy can eliminate the need for invasive aortic arch resection. It also eliminates the false lumen and produces satisfactory early and midterm postoperative results. Therefore, it can be an alternative to hemiarch and total arch replacements, which are based on a conventional "tear-oriented resection" strategy.

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; 2) Blunt traumatic thoracic aortic injury; 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 ruptured descending thoracic aortic aneurysms 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.

Acute aortic syndromes: diagnosis and management, an update

Acute aortic syndromes (AAS) encompass a constellation of life-threatening medical conditions including classic acute aortic dissection (AAD), intramural haematoma, and penetrating atherosclerotic aortic ulcer. Given the non-specific symptoms and physical signs, a high clinical index of suspicion is necessary to detect the disease before irreversible lethal complications occur. In order to reduce the diagnostic time delay, a comprehensive flowchart for decision-making based on pre-test sensitivity of AAS has been designed by the European Society of Cardiology guidelines on aortic diseases and should be thus applied in the emergency scenario. When the definitive diagnosis is made, prompt and appropriate therapeutic interventions should be undertaken if indicated by a highly specialized aortic team. Urgent surgery for AAD involving the ascending aorta (Type A) and medical therapy alone for AAD not involving the ascending aorta (Type B) are typically recommended. In complicated Type B AAD, thoracic endovascular aortic repair (TEVAR) is generally indicated. On the other hand, in uncomplicated Type B AAD, pre-emptive TEVAR rather than medical therapy alone to prevent late complications, while intuitive, requires further study in randomized cohorts. Finally, it should be highlighted that there is an urgent need to increase awareness of AAS worldwide, including dedicated education/prevention programmes, and to improve diagnostic and therapeutic strategies, outcomes, and lifelong surveillance.

Surgical Outcomes And Postoperative Descending Aorta Morphologic Remodeling After Thoracic Endovascular Aortic Repair For Acute And Chronic Type B Aortic Dissection

Background

This study aims to investigate the descending aortic morphological alterations caused by pathological changes in acute and chronic Type B aortic dissection (TBAD) and morphological remodeling after thoracic endovascular aortic repair (TEVAR).

Patients and methods

From February 2012 to January 2016, 86 TBAD patients undergoing TEVAR were divided into an acute group (n=63) and a chronic group (n=23). The areas of the true, false and maximal lumen and descending aorta morphological parameters, including the taper ratio (TR), oversizing ratio (OR), mismatch ratio (MR), radius of curvature (RoC) and tortuosity index (TI), were evaluated. Follow-ups were performed postoperatively before discharge, at 1 and 6 months, and yearly thereafter.

Results

Before TEVAR, the TR (0.57 (0.49) vs 0.74 (0.60); P < 0.05), OR (2.75 ± 1.89 vs 3.96 ± 2.27; P < 0.05) and TI (1.22 (1.19) vs 1.41 ± 0.17; P < 0.05) were significantly higher in the chronic group than in the acute group. The TEVAR technical success rate was 100%. No differences were found in 30-day and >30-day mortality between the two groups. Pathology-specific devices, such as tapered stent grafts and distal bare stents, were used more frequently in the chronic group than in the acute group (47.8% vs 23.8%, P = 0.03; 43.5% vs 12.7%, P = 0.002, respectively). The OR and TI changes that occurred after TEVAR were significantly higher in the chronic group than in the acute group (1.80 ± 0.86 vs 2.98 ± 1.85, P = 0.028; 0.00 ± 0.09 vs 0.09 ± 0.10, P < 0.001, respectively).

Conclusion

TEVAR is a safe and effective therapy for acute and chronic TBAD. Compared to acute TBAD, chronic TBAD resulted in an adverse preoperative descending aorta morphology. Pathology-specific devices may be a feasible treatment option for endovascular repair of chronic TBAD. A larger series of cases with longer follow-up are needed to draw definitive conclusions.

Combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) versus conventional proximal descending aortic stent graft repair for complicated type B aortic dissections

BACKGROUND

Aortic dissection is a separation of the aortic wall, caused by blood flowing through a tear in the inner layer of the aorta. Aortic dissection is an infrequent but life-threatening condition. The incidence of aortic dissection is 3 to 6 per 10,000 per year in the Western population, and can be up to 43 per 10,000 per year in the Eastern population. Over 20% of people with an aortic dissection do not reach a hospital alive. After admission, the mortality rates for people with an aortic dissection are between 10% and 20% for those who received endovascular treatment, and between 20% and 30% for those who had open surgery. Thoracic endovascular aortic repair (TEVAR) is the standard endovascular method to treat complicated type B aortic dissection (aortic dissections without involvement of the ascending aorta). Although TEVAR is less invasive than open surgery and has a better long-term aortic remodeling effect than conservative medical treatment, favourable aortic remodelling is usually limited to the thoracic aortic segment. TEVAR cannot be extended into the abdominal aorta because it could cover the ostia of the reno-visceral arteries. Thus, the abdominal aorta is still at risk of progressive aneurysmal degeneration. The PETTICOAT (provisional extension to induce complete attachment) technique, with proximal endograft and distal bare metal stent, was proposed in 2006 to address this issue. The concept of this technique was to implant a distal bare metal stent into the aortic true lumen, distal to the proximal endograft, to stabilize the distal collapsed intimal flap, while allowing blood flow to reno-visceral arteries. Therefore, the PETTICOAT technique was considered to be related to a more extensive aortic remodelling for people with type B aortic dissection, especially in the area of the abdominal aorta. However, it is still unclear whether the PETTICOAT technique is superior to standard TEVAR.

OBJECTIVES

To assess the effects of combined proximal descending aortic endografting plus distal bare metal stenting versus conventional proximal descending aortic stent graft repair for treating complicated type B aortic dissections.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 5 November 2018. We also undertook reference checking and citation searching to identify additional studies.

SELECTION CRITERIA

We considered all randomised controlled trials which compared the outcome of complicated type B aortic dissection, when treated by combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) versus conventional proximal descending aortic stent graft repair.

DATA COLLECTION AND ANALYSIS

Two independent review authors assessed all references identified by the Cochrane Vascular Information Specialist. We planned to undertake data collection and analysis in accordance with recommendations described in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We found no trials that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

We identified no randomised controlled trials and therefore cannot draw any definite conclusion on this topic. Evidence from non-randomised studies appears to be favourable in the short-term, for combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) to solve the problem of unfavourable distal aortic remodeling. Randomised controlled trials are warranted to provide solid evidence on this topic. Evidence from cohort studies with large sample sizes would also be helpful in guiding clinical practice.

Expanded Petticoat technique to promote the reduction of contrasted false lumen volume in patients with chronic type B aortic dissection

OBJECTIVE

This study examined the outcomes of our novel concept of expanded provisional extension to induce complete attachment strategy (Petticoat) for safety, durability, and remodeling of chronic type B dissections.

METHODS

Twenty patients with chronic type B aortic dissection with aneurysmal degeneration qualified for an expanded Petticoat strategy (stent graft in the thoracic, plus additional distal bare stent into the abdominal and infrarenal aorta, followed by parallel stent grafts into common iliac arteries). Computed tomography was performed preoperatively and at 1, 6, and 12 months after surgery.

RESULTS

The primary technical success was 100%. The 30-day mortality rate was 0%. At 12 months, favorable aortic remodeling and complete false lumen (FL) thrombosis were noted as 100% in the thoracic and infrarenal aorta. The volume of contrast-enhanced FL decreased from 186 ± 75.4 mL all along the dissection preoperatively (range, 70-360 mL), to 6.32 ± 5.4 mL postoperatively (range, 0.0-19.6 mL) and was only observed in the visceral aorta (P = .000089). Despite persistent flow in a small area of the FL, the maximal aortic size was stable in follow-up. Neither paraplegia nor visceral branch occlusion were noted in the follow-up.

CONCLUSIONS

The treatment of aortic dissections with an expanded Petticoat strategy seems to be safe and offers good early results. It significantly reduced the volume of contrast enhanced FL. Further investigation of any subsequent results will be necessary.

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.

Medical therapy versus TEVAR for uncomplicated type B aortic dissection

The standard of care in uncomplicated acute type B aortic dissection (uTBAD) has been optimal medical management. Surgical repair and endovascular interventions are adjuncts in managing complicated type B dissection. Increasing safety and confidence in the thoracic endovascular aortic repair (TEVAR) and recent data indicating long-term complications in medical management of uTBAD has brought a shift in treatment approach. TEVAR at best remains controversial, yet there is a subset, which will definitely benefit from intervention.