Economic Impacts of Treatment for Type II or III Thoracoabdominal Aortic Aneurysm in the United States

Efficacy and Safety of Endovascular Fenestrated and Branched Grafts Versus Open Surgery in Thoracoabdominal Aortic Aneurysm Repair: An Updated Systematic Review, Meta-analysis, and Meta-regression

OBJECTIVE

To provide an updated systematic review and meta-analysis with meta-regression of efficacy and safety of fenestrated/branched endovascular repair of thoracoabdominal aortic aneurysms (TAAAs) compared with open repair.

BACKGROUND

Endovascular repair of TAAAs may be a promising alternative to open surgery by reducing invasiveness and expanding the eligible population, but evidence remains limited.

METHODS

We applied "Prepared Items for Systematic Reviews and Meta-analysis" guidelines to retrieve, quantitatively pool, and critically evaluate the efficacy and safety (including 30-day mortality, reintervention, spinal cord injury [SCI], and renal injury) of both approaches. Original studies were retrieved from PubMed, Embase, and Cochrane Library until April 20, 2022, excluding papers reporting <10 patients. Pooled proportions and means were determined using a random-effect model. Heterogeneity between studies was evaluated with I2 statistics.

RESULTS

Sixty-four studies met the predefined inclusion criteria. Endovascular cohort patients were older and had higher rates of comorbidities. Endovascular repair was associated with similar proportions of mortality (0.07, 95% confidence intervals [CI]: 0.06-0.08) compared with open repair (0.09, 95% CI: 0.08-0.12; P = 0.22), higher proportions of reintervention (0.19, 95% CI: 0.13-0.26 vs 0.06, 95% CI: 0.04-0.10; P < 0.01), similar proportions of transient SCI (0.07, 95% CI: 0.05-0.09 vs 0.06, 95% CI: 0.05-0.08; P = 0.28), lower proportions of permanent SCI (0.04, 95% CI: 0.03-0.05 vs 0.06, 95% CI: 0.05-0.07; P < 0.01), and renal injury (0.08, 95% CI: 0.06-0.10 vs 0.13, 95% CI: 0.09-0.17; P = 0.02). Results were affected by high heterogeneity and potential publication bias.

CONCLUSIONS

Despite these limitations and the lack of randomized trials, this meta-analysis suggests that endovascular TAAA repair could be a safer alternative to the open approach.

In-hospital cost-effectiveness analysis of open versus staged fenestrated/branched endovascular elective repair of thoracoabdominal aneurysms

OBJECTIVE

To compare costs and effectiveness of elective open (OR) versus fenestrated/branched endovascular (ER) repair of thoracoabdominal aneurysms (TAAA) in a high-volume center.

METHODS

This single-center retrospective observational study (PRO-ENDO TAAA Study, NCT05266781) was designed as part of a larger Health Technology Assessment analysis. All electively treated TAAAs between 2013 and 2021 were analyzed and propensity-matched. Endpoints were clinical success, major adverse events (MAE), hospital direct costs, and freedom from all causes and aneurysm-related mortality and reinterventions. Risk factors and outcomes were homogeneously classified according to the Society of Vascular Surgery reporting standards. Cost-effectiveness value (CEV) and Incremental Cost-Effectiveness Ratio (ICER) were calculated, considering the absence of MAEs as a measure of effectiveness.

RESULTS

Propensity matching identified 102 pairs of patients out of 789 TAAAs. Mortality, MAE, permanent spinal cord ischemia rates, respiratory complications, cardiac complications, and renal injury were higher for OR (13% vs 5%, p=.048; 60% vs 17%, p<.001; 10% vs 3%, p=.045; 91% vs 18%, p<.001; 16% vs 6%, p=.024; 27% vs 6%, p<.001; respectively). Access complication rate (6% vs 27%; p<.001) was higher in the ER group. Intensive Care Unit stay was longer (p<.001) for OR and ER patients were discharged home more frequently (3% vs 94%; p<.001). No differences in mid-term endpoints were observed at 2 years. Despite ER reducing all the hospital cost items (-42% to -88%, p<.001), the higher expenses (p<.001) of the endovascular devices increased the overall cost of ER by 80%. CEV for ER was favorable to OR (56 365 vs 64 903 €/patient) with an ICER of 48 409 € per MAE saved.

CONCLUSIONS

ER of TAAA reduces perioperative mortality and morbidity compared to OR, with no differences in reinterventions and survival rates at midterm follow-up. Despite the expenses for endovascular grafts, ER resulted more cost-effective in preventing MAEs.

Spinal Cord Ischemia After Thoracoabdominal Aortic Aneurysms Endovascular Repair: From the Italian Multicenter Fenestrated/Branched Endovascular Aneurysm Repair Registry

PURPOSE

The aim of this study is to report an Italian multicenter experience analyzing the incidence and the risk factors associated with spinal cord ischemia (SCI) in a large cohort of thoracoabdominal aortic aneurysms (TAAAs) treated by fenestrated-branched endovascular aneurysm repair (F-/B-EVAR).

MATERIALS AND METHODS

All consecutive patients undergoing F-/B-EVAR in 4 Italian university centers between 2008 and 2019 were prospectively recorded and retrospectively analyzed. Spinal cord ischemia, 30 day/in-hospital adverse events, and mortality were assessed as early outcomes. Risk factors for SCI were determined by multivariable analysis.

RESULTS

A total of 351 patients received F-/B-EVAR for a TAAA. Twenty-eight (8.0%) patients died within 30 postoperative days or during the hospitalization. Regarding SCI, 47 patients (13.4%) developed neurological symptoms related to spinal cord impaired perfusion. Among them, 17 (4.8%) had a major permanent impairment. The multivariable analysis identified that SCI was associated with Crawford extent I to III (odds ratio [OR]: 20.90, p=0.004, 95% confidence interval [CI]=2.69-162.57), and with endovascular procedures performed for ruptured TAAA (OR: 5.74, p=0.010, 95% CI=1.53-21.57). Spinal cord ischemia was also significantly associated with a grade 3 bleeding during the visceral stage (OR: 4.34, p=0.005, 95% CI=1.55-12.16) and a grade 2 renal insufficiency at 30 days (OR: 7.45, p=0.002, 95% CI=2.12-26.18).

CONCLUSION

The present study indicates that SCI is still an open issue after extent I to III TAAA endovascular repair, while its incidence in extent IV TAAA and pararenal/juxtarenal aneurysms is rare. Thoracoabdominal aortic aneurysms extension, urgent TAAA repair for rupture, severe bleeding, and 30 day renal insufficiency have been identified as significant risk factors for SCI. In the presence of such factors, adjunctive strategies may be considered to reduce SCI rates, while in low-risk patients invasive or potentially-risky maneuvers might not be justified.

Microarray expression profile analysis of long non-coding RNAs in thoracic aortic aneurysm

Thoracic aortic aneurysm (TAA) is a highly lethal vascular disease. Long non-coding RNAs (lncRNAs) are newly discovered as a regulator of protein genes and play critical roles in cardiovascular physio-pathological processes. However, there were a few studies looking at lncRNAs in TAA. In this study, we profiled differential expression of lncRNAs between TAA (TAA group, N = 6) and normal thoracic aorta (control group, n = 6) by third-generation lncRNA microarray. We identified 1352 up-regulated and 1624 down-regulated lncRNAs with differential expression (log fold-change > 2.0, p < 0.01). Through nearby protein-coding gene associated with extracellular matrix (ECM) metabolism and vascular smooth muscle cell (VSMC) apoptosis, 12 up-regulated and 9 down-regulated lncRNAs were selected for further analysis. By calculating phastCons score of base, we identified 8 candidate lncRNAs (4 up-regulated and 4 down-regulated) with high conservation across species. By tissue specificity analysis, we found that 5 lncRNAs (HIF1A-AS1, RP11-465L10.10, LOC100506472, CTD-2184D3.5 and RP-399O19.5) were highly expressed in aortic tissues, suggested that they may be closely associated with TAA. Among them, 2 lncRNAs (RP11-465L10.10 and CTD-2184D3.5) with higher specificity in aorta (p < 0.01) were analyzed by bioinformatics. Further catRAPID analysis revealed a strong RNA-protein interaction between RP11-465L10.10 and myeloid zinc finger gene 1 (MZF1), a transcription factor of MMP9. However, no intense RNA-protein interactions were observed between CTD-2184D3.5 and transcript factors of MAPK6. In conclusions, our study showed differential expression profiles of lncRNAs in TAA and revealed the interaction between certain lncRNAs and coding genes. These data provides insights into new biomarker and therapeutic targets for TAA.