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

Pre-Emptive Endovascular Repair for Uncomplicated Type B Dissection - Is This an Option?

Type B aortic dissection (TBAD) primarily affects men aged 60-65 years, with hypertension in over 80% of cases. The gold standard for the treatment of uncomplicated acute TBAD is Best Medical Treatment (BMT), which focused on controlling blood pressure and heart rate. However, Thoracic Endovascular Aortic Repair (TEVAR) has gained attention over the years, especially for complicated TBAD cases, by covering the primary entry tear, lowering false lumen pressure, and promoting aortic remodeling. TBAD can be classified according to the onset of symptoms into acute, subacute and chronic stages, with different intervention implications at each stage. Studies such as the Acute Dissection Stentgraft OR Best Medical Treatment and Investigation of STEnt grafts in Acute Dissection trials have shown the benefits of TEVAR over BMT, particularly in promoting aortic remodeling and reducing long-term aorta-related mortality. However, these trials noted no significant difference in immediate mortality. TEVAR timing is crucial, as early intervention in the acute phase can lead to higher complication rates due to higher intimal fragility. As a result, the subacute phase offers a balance, allowing beneficial remodeling with a lower complication rate.

Treatment of Type B Aortic Dissections

Treatment of patients with Type B aortic dissections (TBADs) remains challenging due to both anatomic and medical complexities. This article outlines the current management considerations for patients with TBAD.

Critical Review of Guidelines for Type B Aortic Dissection

The management of type B aortic dissection is one of the most challenging and debated topics in contemporary cardiovascular surgery practice. Patients with acute or chronic dissection-related complications face high morbidity and mortality if not treated promptly. For most patients requiring intervention, thoracic endovascular aortic repair (TEVAR) is considered the gold standard. However, both early and late TEVAR-related complications make decision-making complex, even for experienced clinicians. In many cases, optimal medical management with longitudinal imaging surveillance may be preferred. In response to these challenges, several societal guidelines have recently been published to provide evidence-based or expert consensus "best practice" recommendations. Although these guidelines share many commonalities, they also highlight key unresolved clinical questions. For example, debates persist over the appropriate use of TEVAR for "uncomplicated" TBAD, defining "high-risk" criteria for uncomplicated presentations, and management of the false lumen, among other topics. Despite recent updates, a critical evaluation of the nuanced differences between these guidelines is lacking. Therefore, the purpose of this review is to compare current clinical practice guidelines, highlight their similarities and differences, and offer a comprehensive evaluation of the evidence surrounding management of TBAD. Moreover, this analysis will provide recommendations to address important knowledge gaps.

Initial aortic repair versus medical therapy for early uncomplicated type B dissections

BACKGROUND

Uncomplicated type B aortic dissections was regarded benign and treated with optimal medical therapy (OMT). However, studies showed highly unpredictable of disease progression, which suggested the need of earlier intervention. To search for features associated with worse outcomes with OMT is important due to risk of intervention. We investigated mortality and aortic remodeling between aggressive (OMT and pre-emptive endovascular intervention) and conservative therapy (OMT and necessary operations).

METHODS

Retrospective analysis was performed in acute and subacute uncomplicated type B dissections patients, including typical aortic dissection, intramural hematoma and penetrating atherosclerotic ulcer, diagnosed between June 2005 and May 2021. Patients with Marfan, traumatic, iatrogenic, zone 0 (ascending aorta) involvement, and maximal aortic diameter > 45mm were excluded. Patients are classified according to initial management.

RESULTS

77 and 33 patients in the aggressive and conservative groups were included respectively. There was no differences in baseline clinical and radiological characteristics between them. During mid-term follow-up (median 62.5 months), there was no difference in the mortality but the incidence of 30-day acute kidney injury was significantly higher in aggressive group. Positive aortic remodeling was noted in aggressive group, with development to complete or incomplete false lumen thrombosis (p < 0.01).

CONCLUSION

Aggressive pre-emptive endovascular therapy though has acceptable outcomes and positive aortic remodelling in early uncomplicated type B dissection with maximal aortic diameter ≤ 45mm. However, it could not translate into better mid-term survival than conservative therapy, but with higher risk of 30-day acute kidney injury. Aggressive pre-emptive endovascular intervention should be cautious in these patients.

Early three-dimensional growth in uncomplicated type B aortic dissection is associated with long-term outcomes

OBJECTIVE

Late adverse events (LAEs) are common among initially uncomplicated type B aortic dissection (uTBAD); however, identifying those patients at highest risk of LAEs remains a significant challenge. Early false lumen (FL) growth has been suggested to increase risk, but confident determination of growth is often hampered by error in two-dimensional clinical measurements. Semi-automated three-dimensional (3D) mapping of aortic growth, such as by vascular deformation mapping (VDM), can potentially overcome this limitation using computed tomography angiograms (CTA). We hypothesized that FL growth in the early pre-dissection phase by VDM can accurately predict LAEs.

METHODS

We performed a two-center retrospective study of patients with uTBAD, with paired CTAs in the acute (1-14 days) and subacute/early chronic (1-6 months) periods. VDM analysis was used to map 3D growth. Standard clinical CT measures (ie, aortic diameters, tear characteristics) were also collected. Multivariate analysis was conducted using a decision tree and Cox proportional hazards model. LAEs were defined as aneurysmal FL (>55 mm); rapid growth (>5 mm within 6 months); aorta-specific mortality, rupture, or re-dissection.

RESULTS

A total of 107 (69% male) patients with uTBAD initially met inclusion criteria with a median follow-up of 7.3 years (interquartile range [IQR], 4.7-9.9 years). LAEs occurred in 72 patients (67%) at 2.5 years (IQR, 0.7-4.8 years) after the initial event. A multivariate decision tree model identified VDM growth (>2.1 mm) and baseline diameter (>42.7 mm) as optimal predictors of LAEs (area under the receiver operating characteristic curve = 0.94), achieving an 87% accuracy (sensitivity of 93%, specificity of 76%) after leave-one-out validation. Guideline reported high-risk features were not significantly different between groups.

CONCLUSIONS

Early growth of the FL in uTBAD was the best tested indicator for LAEs and improves upon the current gold-standard of baseline diameter in selecting patients for early prophylactic thoracic endovascular aortic repair.

Variability in the Treatment of High-Risk Type B Aortic Dissection at a Single Center

Although there are established high-risk features in acute type B aortic dissection (TBAD), its management is variable. This study characterizes complicated, uncomplicated, and high-risk TBAD in addition to their management and outcomes to gain insight into the actual significance of these high-risk features and the reality of real-world practice in managing TBAD. A retrospective review of 62 patients was conducted. Patient demographics, management, and outcomes were characterized and evaluated with Pearson's χ2 test, Fisher's exact test, or analysis of variance. Of the 32 high-risk TBADs, 66% (n = 21) received endovascular repair, 31% (n = 10) were medically managed, and 3% (n = 1) received hybrid (open and endovascular) repair. Refractory hypertension and pain (52%, n = 11) were the most common high-risk features in patients with high-risk TBAD who received endovascular repair. A maximum aortic diameter of >40 mm (67%, n = 6) was the most common high-risk feature in patients who received medical management. The most prevalent high-risk feature for all treatment groups in the high-risk TBADs was an aortic diameter of >40 mm (n = 16; 50%). Adverse postoperative outcomes were highest in the high-risk and complicated groups with endoleak as the most common adverse outcome (high-risk 12.9%, complicated 13.6%). Of the 62 patients, 47% (n = 26) had follow-up since their admission with an average follow-up time of 69 ± 166 days. The significance of high-risk features in the management of high-risk TBAD remains unclear. This single-center experience with managing acute TBAD reveals the reality of inadequate follow-up that may be specific to this disease process. This highlights a need to direct more efforts to assess long-term outcomes after treatment.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL IMPACT

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

Thoracic endovascular aortic repair for hyperacute, acute, subacute and chronic type B aortic dissection: Meta-analysis of reconstructed time-to-event data

Since the optimal timing for thoracic endovascular aortic repair (TEVAR) in the context of type B aortic dissections (TBAD) remains an open question, we performed a systematic review with meta-analysis to evaluate outcomes of TEVAR according to the phases of TBAD - hyperacute, acute, subacute and chronic. We carried out a pooled meta-analysis of time-to-event data extracted from studies published by June 2023 for the following outcomes: all-cause mortality, aortic-related mortality, and late aortic reinterventions. Thirteen studies met our eligibility criteria, comprising 4,793 patients (10.3 % hyperacute, 51.9 % acute, 25.9 % subacute, 11.9 % chronic). Considering the overall population, we observed a statistically significant difference between the groups (Log-rank test, P < 0.0001) and the main differences were found in the following comparisons: hyperacute versus acute (HR 1.61; 95 %CI 1.21-2.13; P = 0.001); hyperacute versus chronic (HR 1.70; 95 %CI 1.17-2.46; P = 0.005); subacute versus acute (HR 0.78; 95 %CI 0.63-0.98; P = 0.032). Considering the population with uncomplicated TBAD, we also observed a statistically significant difference for all-cause death between the groups (Log-rank test, P < 0.0001) and the main differences were found in the comparisons for subacute versus acute (HR 0.72; 95 %CI 0.58-0.88; P = 0.002). Furthermore, we observed statistically significant differences between the groups for aortic-related death (Log-rank test, P < 0.0001) and late aortic reintervention (Log-rank test, P < 0.0001), all favoring mostly the subacute phase as the optimal timing for TEVAR. In conclusion, there seems to be a timing-specific difference in the outcomes of TEVAR for TBAD pointing to the subacute phase as the optimal timing to achieve better long-term outcomes.

Outcomes of Patients with Acute Type B Aortic Dissection and High-Risk Features

BACKGROUND

Recently the Society for Vascular Surgery (SVS) and Society for Thoracic Surgeons (STS) published contemporary guidelines clearly defining complicated versus uncomplicated acute type B aortic dissections (TBADs) with an additional high-risk grouping. Few studies have evaluated outcomes associated with "high-risk" TBADs. The objective of this study was to assess differences in demographics, clinical presentation, symptom onset, and outcomes in high-risk patients that underwent either thoracic endovascular aortic repair (TEVAR) or best medical management for acute TBAD compared to those with complicated and uncomplicated acute TBAD.

METHODS

Patients admitted with acute TBADs from a single academic medical center from October 2011 to March 2020 were analyzed. Per the STS/SVS 2020 guidelines, high risk was defined as refractory pain/hypertension, bloody pleural effusion, aortic diameter >4 cm, false lumen diameter >22 mm, radiographic malperfusion, and early readmission, and complicated was defined as ruptured/malperfusion presentation. Uncomplicated patients were those without malperfusion/rupture and without high-risk features. The primary end-point was inpatient mortality. Secondary end-points included complications, reintervention, and survival.

RESULTS

Of the 159 patients identified with acute TBAD, 63 (40%) met the high-risk criteria. In the high-risk cohort, 38 (60%) underwent TEVAR (HR-TEVAR), with refractory pain as the most common indication, while 25 (40%) were managed medically (HR-medical). Malperfusion or rupture was present in 63 (40%) patients (complicated TBAD (C-TBAD)), all of whom underwent TEVAR. An additional 33 patients had no high-risk features and were all managed medically (uncomplicated TBAD). There were no differences in age, body mass index, and race between groups. Among the 4 groups, there were variable distributions in sex, insurance status, and incidence of several baseline comorbidities including congestive heart failure, chronic obstructive pulmonary disease, and renal dysfunction (P < 0.05 for all). C-TBAD had increased length of stay (12, interquartile range [IQR] 9-22) compared to HR-TEVAR (11.5, IQR 7-15), HR-medical (6, IQR 5-8), and uncomplicated TBAD (7, IQR 5-10) (P < 0.01). C-TBAD had decreased days from admission to repair (0, IQR 0-2) compared to HR-TEVAR (3.5, IQR 1-8) (P < 0.01). C-TBAD patients had worse 3-year survival compared to other groups (log-rank P < 0.01), although when in-hospital mortality was excluded, survival was similar among groups (P = 0.37). Of patients initially managed medically, outpatient TEVAR was performed in 6 (24%) HR-medical and 4 (12%) uncomplicated patients, with no difference between rate of intervention between groups (P = 0.22).

CONCLUSIONS

High-risk features, as defined in updated SVS/STS guidelines, are common in patients presenting with acute TBAD. High-risk patients had acceptable outcomes when managed either surgically or medically. High-risk patients that underwent TEVAR had improved perioperative outcomes and mortality compared to those undergoing TEVAR for C-TBAD, a finding which may help guide preoperative risk stratification and patient counseling.

Spinal cord ischemia and reinterventions following thoracic endovascular repair for acute type B aortic dissections

OBJECTIVE

The technical aspects of thoracic endovascular aortic repair (TEVAR) for acute type B aortic dissection (TBAD), specifically the location of proximal seal zone (PSZ) (need to cover the left subclavian artery [LSA]), distal seal zone (DSZ) (length of aortic coverage), benefit of LSA revascularization, and prophylactic lumbar drainage are still debated. Each of these issues has potential benefits but also has known risks. This study aims to identify factors associated with reintervention and spinal cord ischemia (SCI) following TEVAR for acute TBAD with a zone 3 entry tear.

METHODS

The Vascular Quality Initiative was queried for TEVARs performed for acute TBAD with zone 3 entry tear, zone 3 proximal zone of disease, treated with TEVAR extending between zone 2 and zone 5. The primary outcomes were SCI and related reintervention. Secondary outcomes were stroke, arm ischemia, and retrograde type A dissection (RTAD). The exposure variables were PSZ 2 vs 3, DSZ 4 vs 5, prophylactic lumbar drain, and LSA revascularization. Univariate analyses were conducted with χ2 analysis, and multivariable logistic regression was used to evaluate association with outcomes.

RESULTS

Of 583 patients who met inclusion criteria, 266 had PSZ 2 and 317 had PSZ 3. On univariate analysis, PSZ 2 was associated with a higher rate of reintervention, but PSZ2 was not significant on multivariable analysis after accounting for age, sex, race, smoking, PSZ, DSZ, prophylactic lumbar drain, and LSA patency. PSZ 2 was not associated with SCI, arm ischemia, or RTAD. PSZ 2 was associated with a trend towards a higher rate of stroke. DSZ 4 and DSZ 5 were performed in 161 and 422 TEVARs, respectively, and DSZ 5 was associated with a higher rate of SCI on univariate (3 [1.9%] vs 39 [9.2%]; P = .01) and multivariable (odds ratio, 7.384; 95% confidence interval, 2.193-24.867; P = .001) analyses. Prophylactic lumbar drain placement was not statistically significantly associated with SCI, but lack of postoperative LSA patency was associated with SCI (odds ratio, 2.966; 95% confidence interval, 1.016-8.656; P = .05).

CONCLUSIONS

This study found that PSZ 2 was not associated with lower reinterventions or higher rates of SCI but trended towards a higher rate of stroke than PSZ 3. Additionally, DSZ 5 was strongly associated with SCI when compared with DSZ 4, highlighting the importance of limiting aortic coverage to coverage of the proximal entry tear when possible.

A computational study of artery curvature and endograft oversize influence on seal zone behavior in endovascular aortic repair

Thoracic endovascular aortic repair (TEVAR) is a minimally invasive procedure involving the placement of an endograft inside the dissection or an aneurysm to direct blood flow and prevent rupture. A significant challenge in endovascular surgery is the geometrical mismatch between the endograft and the artery, which can lead to endoleak formation, a condition where blood leaks between the endograft and the vessel wall. This study uses computational modeling to investigate the effects of artery curvature and endograft oversizing, the selection of an endograft with a larger diameter than the artery, on endoleak creation. Finite element analysis is employed to simulate the deployment of endografts in arteries with varying curvature and diameter. Numerical simulations are conducted to assess the seal zone and to quantify the potential endoleak volume as a function of curvature and oversizing. A theoretical framework is developed to explain the mechanisms of endoleak formation along with proof-of-concept experiments. Two main mechanisms of endoleak creation are identified: local buckling due to diameter mismatch and global buckling due to centerline curvature mismatch. Local buckling, characterized by excess graft material buckling and wrinkle formation, increases with higher levels of oversizing, leading to a larger potential endoleak volume. Global buckling, where the endograft bends or deforms to conform to the centerline curvature of the artery, is observed to require a certain degree of oversizing to bridge the curvature mismatch. This study highlights the importance of considering both curvature and diameter mismatch in the design and clinical use of endografts. Understanding the mechanisms of endoleak formation can provide valuable insights for optimizing endograft design and surgical planning, leading to improved clinical outcomes in endovascular aortic procedures.

Timing of Intervention and Long-Term Outcomes of Type B Aortic Intramural Hematoma with Intimal Disruption at Admission

BACKGROUND

To compare the 30-day and long-term outcomes between patients with concomitant type B intramural hematoma and intimal disruption upon admission who underwent endovascular repair in the acute or subacute phases.

METHODS

Data were extracted from January 1, 2010, to December 31, 2019. Logistic regression and Cox regression were performed to evaluate the impact of timing of intervention on 30-day and long-term outcomes, respectively.

RESULTS

The study included 241 patients, among which 159 were in the acute group. No significant difference was observed in 30-day mortality (0.6% vs. 0%, P = 1), 30-day complication rate (2.5% vs. 1.2%, P = 0.664), long-term all-cause mortality (10.7% vs. 7.3%, P = 0.540), and aortic reintervention rate (2.5% vs. 2.4%, P = 1) between the acute and subacute group. In multivariable analysis, the timing of intervention was not associated with 30-day mortality (odds ratio (OR) = 0, 95% confidence interval CI: 0-Inf, P = 0.999), 30-day complication (OR = 0.30, 95% CI: 0.02-3.77, P = 0.348), long-term mortality (hazard ratio = 0.56, 95% CI: 0.20-1.61, P = 0.283), and aortic reintervention (OR = 0.97, 95% CI: 0.15-6.08, P = 0.970).

CONCLUSIONS

For patients with concomitant type B intramural hematoma and intimal disruption upon admission, there is no significant difference in 30-day and long-term outcomes between those who undergo endovascular treatment in the acute or subacute phase.

Endovascular repair of acute vs. subacute uncomplicated type B aortic dissection: a systematic review and meta-analysis

Objective

This study aimed to conduct a meta-analysis evaluating the optimal timing for endovascular repair of acute versus subacute uncomplicated Type B Aortic Dissection.

Method

PubMed, EMBASE, web of science and Cochrane Library was interrogated to identify Electronic bibliographic studies updated to January 2023 to collect studies compared the clinical outcomes of endovascular repair for Acute Versus Subacute Uncomplicated Type B Aortic Dissection. Data were aggregated as pooled odds ratios (OR) using the fixed or random effects models according to the significance of heterogeneity, Pooled odds ratios (OR) were calculated by RevMan 5.3 and applied with fixed or random-effect models.

Result

A comprehensive literature search found 322 citations published and finally among them 6 studies containing 3,769 patients (acute group 2,642, subacute group 1,127) were included in review. There is an increased risk of 30-day complications (OR = 1.51,95%CI,1.26-1.81) 30-day mortality (OR = 2.39,95%CI, 1.55-3.67) and 1-year mortality (OR = 1.71,95%CI,1.27-2.30) for an acute uTBAD group compared to subacute ones. Similarly, reintervention was more likely in the acute group than in the subacute group (OR = 1.42,95%CI,1.05-1.91). However, no significant differences were found in long-term mortality.

Conclusion

This meta-analysis confirmed that there was no significant difference in the long-term prognosis between the acute and subacute phases in the timing of surgery. However, considering the high incidence of complications, high re-intervention rate and one-year mortality probably caused by high intima fragility in the acute phase, endovascular repair at subacute phase appears to favorably compare with acute strategy. But future studies with adequate patient numbers and longer-term follow-up are necessary to further verify the study conclusion.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021247609, identifier PROSPERO CRD42021247609.

A comparison of endovascular repair to medical management for acute vs subacute uncomplicated type B aortic dissections

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) has emerged as a viable option of treatment for uncomplicated type B aortic dissection (UTBAD) due to the potential for inducing favorable aortic remodeling. The aim of this study is to compare outcomes of UTBAD treated medically or with TEVAR in either the acute (1 to 14 days) or subacute period (2 weeks to 3 months).

METHODS

Patients with UTBAD between 2007 and 2019 were identified using the TriNetX Network. The cohort was stratified by treatment type (medical management; TEVAR during the acute period; TEVAR during the subacute period). Outcomes including mortality, endovascular reintervention, and rupture were analyzed after propensity matching.

RESULTS

Among 20,376 patients with UTBAD, 18,840 were medically managed (92.5%), 1099 patients were in the acute TEVAR group (5.4%), and 437 patients were in the subacute TEVAR group (2.1%). The acute TEVAR group had higher rates of 30-day and 3-year rupture (4.1% vs 1.5%; P < .001; 9.9% vs 3.6%; P < .001) and 3-year endovascular reintervention (7.6% vs 1.6%; P < .001), similar 30-day mortality (4.4% vs 2.9%; P < .068), and lower 3-year survival compared with medical management (86.6% vs 83.3%; P = .041). The subacute TEVAR group had similar rates of 30-day mortality (2.3% vs 2.3%; P = 1), 3-year survival (87.0% vs 88.8%; P = .377) and 30-day and 3-year rupture (2.3% vs 2.3%; P = 1; 4.6% vs 3.4%; P = .388), with significantly higher rates of 3-year endovascular reintervention (12.6% vs 7.8%; P = .019) compared with medical management. The acute TEVAR group had similar rates of 30-day mortality (4.2% vs 2.5%; P = .171), rupture (3.0% vs 2.5%; P = .666), significantly higher rates of 3-year rupture (8.7% vs 3.5%; P = .002), and similar rates of 3-year endovascular reintervention (12.6% vs 10.6%; P = .380) compared with the subacute TEVAR group. There was significantly higher 3-year survival (88.5% vs 84.0%; P = .039) in the subacute TEVAR group compared with the acute TEVAR group.

CONCLUSIONS

Our results found lower 3-year survival in the acute TEVAR group compared with the medical management group. There was no 3-year survival benefit found in patients with UTBAD who underwent subacute TEVAR compared with medical management. This suggests the need for further studies looking at the necessity for TEVAR when compared with medical management for UTBAD as it is non-inferior to medical management. Higher rates of 3-year survival and lower rates of 3-year rupture in the subacute TEVAR group compared with the acute TEVAR group suggest superiority of subacute TEVAR. Further investigations are needed to determine the long-term benefit and optimal timing of TEVAR for acute UTBAD.

Readmission after early thoracic endovascular aortic repair versus medical management of acute type B aortic dissection

BACKGROUND

The use of thoracic endovascular aortic repair (TEVAR) for the management of acute uncomplicated type B aortic dissection (TBAD) has increased. Although the results from early studies were promising, larger randomized trials evaluating TEVAR are lacking. It is also unclear where sufficient equipoise exists for such trials. In the present study, we evaluated the number of readmissions and unplanned operations after TEVAR vs those after medical management as the initial treatment of acute uncomplicated TBAD and the frequency of each treatment in this population.

METHODS

We performed a multi-institutional retrospective review of patients with acute TBAD from 2015 to 2020 with the 1-year outcomes available, excluding patients with prior aortic intervention or chronic, iatrogenic or traumatic etiologies. The primary exposure was TEVAR vs medical management at the index admission. The patient demographics, clinical presentation, and imaging findings were analyzed using bivariate and multivariate logistic regression for the primary outcomes of unplanned readmission and/or operation after the initial admission. The secondary outcomes were mortality, myocardial infarction, stroke, renal failure requiring dialysis, retrograde type A dissection, and length of stay. We hypothesized that the readmissions would be higher with medical management.

RESULTS

A total of 216 patients with TBAD (47 with complicated and 169 with uncomplicated) from two large academic centers were identified. Of the 169 patients with uncomplicated TBAD, 83 (49%) had been treated medically and 86 (51%) had undergone TEVAR at the initial admission. No differences were found in the demographics or high-risk imaging features at presentation. The medically managed patients had had higher rates of unplanned readmission (34% vs 9%; P = .0001) and operation (28% vs 8%; P = .0007) but shorter lengths of stay (6.3 vs 13.1 days; P < .0001). No differences were found in mortality, although the rate of myocardial infarction was higher in the medically managed group (10.8% vs 2.3%; P = .02). Although 28% of the medically managed patients had later required operation, they had had morbidity and mortality similar to those of patients who had undergone initial TEVAR. Initial medical management was associated with unplanned readmission (odds ratio, 8.3; P = .02) and the need for operation (odds ratio, 4.56; P = .006). No differences were found in the outcomes according to the involved aortic zones.

CONCLUSIONS

In the present study, medical management of acute uncomplicated TBAD was associated with higher rates of readmission and the need for unplanned operation compared with TEVAR. However, no differences were found in the 1-year mortality for the patients for whom medical management had failed. Because one half of the patients had undergone medical management and one half had undergone early TEVAR, this finding suggests clinical equipoise for the treatment of acute uncomplicated TBAD. Therefore, a larger randomized trial appears warranted to determine whether a clear benefit exists for early TEVAR.

Single-branched stent-graft with on-table fenestration for endovascular repair of primary retrograde type A aortic dissection: A multicenter retrospective study

Objective

This study aims to evaluate the feasibility, efficacy, and safety of a single-branched stent-graft with on-table fenestration for primary retrograde type A aortic dissection (RTAD) during thoracic endovascular aortic repair (TEVAR).

Materials and methods

From January 2019 to December 2021, 36 patients with primary RTAD from five tertiary hospitals received medical management in the acute phase. They underwent TEVAR with a proximal zone 1 landing for aortic arch reconstruction in the subacute phase, using a fenestration technique on a single-branched stent-graft. Nearly 2 weeks after admission, computed tomography angiography (CTA) was re-examined to evaluate the thrombosis status of retrograde false lumen (FL). The primary outcomes were technical success, patency of the target branch arteries, and absence of type Ia endoleaks. The second outcomes were stent-graft-related complications and all-cause mortality.

Results

The mean age was 56.2 ± 11.3 years, and 29 (80.6%) were male. After a median interval of 18.0 [interquartile range (IQR), 17.0–20.3] days of medical treatment, the partial and complete thrombosis of proximal FL rates increased to 52.8% and 47.2%, respectively. One patient (2.8%) experienced postoperative type Ia endoleaks, and was successfully re-treated using coli and Onyx glue. The median hospital stay was 20.5 (IQR, 18.0–23.0) days. The overall technical success rate was 100%. The median follow-up time was 31.5 (IQR, 29.8–34.0) months. There was one death (2.8%) due to gastrointestinal bleeding. Distal aortic segmental enlargement (DASE) occurred in two (5.6%) patients. No major complications or recurrent dissections in the proximal landing zone were recorded during follow up.

Conclusion

The retrograde FL in primary RTAD could realize partial or complete thrombosis after medical management in the acute phase, and it might be regarded as a valid proximal landing zone for endovascular repair. The single-branched stent graft with on-table fenestration performed in the subacute phase may be feasible strategy in selective primary RTAD patients.