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

Trends in the incidence, surgical management and outcomes of type B aortic dissections in Australia over the last decade

OBJECTIVES

This study aims to investigate the incidence and in-hospital outcomes of surgical repair for type B aortic dissection (TBAD) in Australia.

METHODS

Data were obtained from the Australasian Vascular Audit (AVA) and the Australian Institute of Health and Welfare (AIHW). The former is a total practice audit mandated for all members of the Australian and New Zealand Society for Vascular Surgery (ANZSVS) while the latter is an independent government agency which records all healthcare data in Australia. All cases of TBAD which underwent surgical intervention (endovascular or open repair) between 2010 and 2019 were identified using prospectively recorded data from the AVA (New Zealand data was excluded). The primary outcomes were temporal trends in procedures and hospital mortality; secondary outcomes were complications and risk factors for mortality. All admissions and procedures for, and hospital deaths from, TBAD in Australia were identified in AIHW datasets using the relevant diagnosis and procedure codes, with age-standardized rates calculated for the period 2000-01 to 2018-19.

RESULTS

A total of 567 cases of TBAD underwent vascular surgical intervention (AVA data, Australia). Of these, 96.3% were treated by endovascular repair. There was an increase in the annual procedure number from 45 in 2010 to 88 in 2019. In-hospital mortality was 4.8% for endovascular repair and 19% for open repair (p = 0.021). From 2000-01 to 2018-19, the age-standardized procedure rates for TBAD (Australia) doubled, the proportion of admitted patients undergoing a procedure rose from 28% to 43%, and in-hospital deaths fell by 25%.

CONCLUSION

There has been an increasing incidence of vascular surgical intervention for TBAD in Australia. The majority of patients received endovascular therapy while the mortality from surgically managed TBAD appears to be falling.

Optimal Timing of Pre-emptive Thoracic Endovascular Aortic Repair in Uncomplicated Type B Aortic Dissection: A Network Meta-Analysis

BACKGROUND

This network meta-analysis compares outcomes of optimal medical therapy (OMT) and pre-emptive thoracic endovascular aortic repair (TEVAR) for uncomplicated type B aortic dissection at different phases of chronicity.

METHODS

MEDLINE and EMBASE were searched through November 2023. Pooled short-term outcomes (short-term mortality, perioperative complications) and long-term outcomes (all-cause mortality, aortic-related mortality, aortic re-intervention rates) were calculated.

RESULTS

Systematic review identified 17 studies (2 randomized controlled trials, 3 propensity score matching, and 2 inverse probability weighting). Subacute-phase intervention had lower short-term mortality than the acute-phase (hazard ratio [HR] [95% confidence interval [CI]]=0.60 [0.38-0.94], p=0.027). No significant differences were observed in aortic rupture and paraplegia. Acute-phase TEVAR had a higher stroke incidence than subacute-phase intervention (HR [95% CI]=2.63 [1.36-5.09], p=0.042), chronic (HR [95% CI]=2.5 [1.03-6.2], p=0.043), and OMT (HR [95% CI]=1.57 [1.12-2.18], p=0.008). Acute-phase TEVAR had higher long-term all-cause mortality than subacute-phase intervention (HR [95% CI]=1.34 [1.03-1.74], p=0.03). Optimal medical therapy had elevated long-term all-cause mortality compared with subacute-phase TEVAR (HR [95% CI]=1.67 [1.25-2.33], p<0.001) and increased long-term aortic-related mortality vs acute-phase (HR [95% CI]=2.08 [1.31-3.31], p=0.002) and subacute-phase (HR [95% CI]=2.6 [1.62-4.18], p<0.01) interventions. No significant differences were observed in aortic re-intervention rates.

CONCLUSIONS

Pre-emptive TEVAR may offer lower all-cause mortality and aortic-related mortality than OMT. Considering lower short-term mortality, perioperative stroke rate, and long-term mortality, our findings support pre-emptive TEVAR during the subacute phase.

CLINICAL IMPACT

The optimal timing of pre-emptive thoracic endovascular aortic repair (TEVAR) for uncomplicated type B aortic dissection remains uncertain. This network meta-analysis suggests that the subacute phase (14-90 days from symptom onset) emerges as the optimal timing for pre-emptive TEVAR. This window is associated with lower rates of short-term complications and higher long-term survival rates compared with alternative strategies.

Meta-analysis of central and peripheral cannulation for type A aortic dissection

BACKGROUND

Acute type A aortic dissection necessitates rapid and effective arterial cannulation techniques for optimal outcomes. This meta-analysis compares the safety and effectiveness of direct aortic cannulation (AoC) with peripheral cannulation (PC) via the femoral or axillary arteries in aortic surgery for acute type A aortic dissection.

METHODS

A systematic review following PRISMA guidelines identified 10 retrospective studies encompassing 2518 patients (961 AoC, 1557 PC). Pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated to analyze perioperative characteristics, short-term mortality rates, and postoperative complications including stroke and acute kidney injury.

RESULTS

Short-term mortality did not significantly differ between AoC and PC (OR [95% CI] = 0.78 [0.61-1.01], p = .06). Likewise, postoperative stroke (OR [95% CI] = 0.86 [0.63-1.17], p = .33) nor acute kidney injury (OR [95% CI] = 1.11 [0.89-1.37], p = .35) showed no significant differences. AoC exhibited shorter operation time whereas there were no significant differences in aortic cross clamp time and cardiopulmonary bypass time between both groups. Our meta-regression analysis, considering the distal extent of aortic replacement, indicated that variations in aortic replacement rates did not significantly impact the observed outcomes.

CONCLUSION

AoC is a viable alternative to PC for acute type A aortic dissection. While both approaches offer comparable outcomes, AoC's advantage in shorter operation time warrants thoughtful consideration in clinical practice.

Association of genetic variants in ULK4 with the age of first onset of type B aortic dissection

Background: The association between autophagy, structural alterations of the aortic wall, and endothelial dysfunction in humans has yet to be fully elucidated. The family of ULK (UNC51-like) enzymes plays critical roles in autophagy and development. This study aimed to evaluate the association between ULK gene family members and patient age of first type B aortic dissection (TBAD) onset.

Methods: The genotype data in a TBAD cohort from China and the related summary-level datasets were analyzed. We applied the sequence kernel association test (SKAT) to test the association between single-nucleotide polymorphisms (SNPs) and age of first onset of TBAD controlling for gender, hypertension, and renal function. Next, we performed a 2-sample Mendelian randomization (MR) to explore the potential causal relationship between ULK4 and early onset of TBAD at the level of gene expression coupled with DNA methylation with genetic variants as instrumental variables.

Results: A total of 159 TBAD patients with 1,180,097 SNPs were included. Concerning the association between the ULK gene family and the age of first onset of the TBAD, only ULK4 was found to be significant according to SKAT analysis (q-FDR = 0.0088). From 2-sample MR, the high level of ULK4 gene expression was related to a later age of first onset of TBAD (β = 4.58, p = 0.0214).

Conclusion: This is the first study of the ULK gene family in TBAD, regarding the association with the first onset age. We demonstrated that the ULK4 gene is associated with the time of onset of TBAD based on both the SKAT and 2-sample MR analyses.