Abdominal aortic aneurysms: endovascular options and outcomes - proliferating therapy, but effective?

Circulating inflammatory proteins and abdominal aortic aneurysm: A two-sample Mendelian randomization and colocalization analyses

OBJECTIVES

Inflammatory proteins are implicated in the progression of abdominal aortic aneurysms (AAA); however, it remains debated whether they are causal or consequential. This study aimed to assess the influence of circulating inflammatory proteins on AAA via two-sample Mendelian randomization (MR) and colocalization analysis.

METHODS

Summary data on 91 circulating inflammatory protein levels were extracted from a comprehensive protein quantitative trait loci (pQTL) study involving 14,824 individuals. Genetic associations with AAA were derived from the FinnGen study (3,869 cases and 381,977 controls). MR analysis was conducted to assess the relationships between proteins and AAA risk. Colocalization analysis was employed to explore potential shared causal variants between identified proteins and AAA.

RESULTS

Using a two-sample bidirectional MR study, our findings suggested that genetically predicted elevated levels of TGFB1 (OR = 1.21, P = 0.003), SIRT2 (OR = 1.196, P = 0.031) and TNFSF14 (OR = 1.129, P = 0.034) were linked to an increased risk of AAA. Conversely, genetically predicted higher levels of CD40 (OR = 0.912, P = 0.049), IL2RB (OR = 0.839, P = 0.028) and KITLG (OR = 0.827, P = 0.008) were associated with a decreased risk of AAA. Colocalization analyses supported the association of TGFB1 and SIRT2 levels with AAA risk.

CONCLUSIONS

The proteome-wide MR and colocalization study identified TGFB1 and SIRT2 as being associated with the risk of AAA, warranting further investigation as potential therapeutic targets.

GRADE-Based Recommendations for Surgical Repair of Nonruptured Abdominal Aortic Aneurysm

The objective of this study was to provide evidence-based recommendations for endovascular aneurysm repair (EVAR) versus open surgical repair (OSR) for patients with a nonruptured abdominal aortic aneurysm (AAA). We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement and adhered to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. Both low- and high surgical risk patients treated with EVAR showed decreased 30-day mortality, but the low-risk group had no differences in 4-year mortality. Compared with friendly anatomy, patients with hostile anatomy had an increased risk of type I endoleak. Young patients may prefer OSR. Endovascular aneurysm repair was not cost-effective in Europe. Four conditional recommendations were formulated: (1) OSR for low-risk patients up to 80 years old, (2) EVAR for low-risk patients older than 80 years, (3) EVAR for high-risk patients as long as is anatomically feasible, and (4) OSR in patients in whom it is not anatomically feasible to perform EVAR. Based on GRADE criteria, either OSR or EVAR can be suggested to patients with nonruptured AAA taking into account their surgical risk, hostile anatomy, and age. Given the weakness of the recommendations, personal preferences are determinant.

Systematic Review and Meta-analysis of Long-term survival After Elective Infrarenal Abdominal Aortic Aneurysm Repair 1969-2011: 5 Year Survival Remains Poor Despite Advances in Medical Care and Treatment Strategies

Background

Improved critical care, pre-operative optimization, and the advent of endovascular surgery (EVAR) have improved 30 day mortality for elective abdominal aortic aneurysm (AAA) repair. It remains unknown whether this has translated into improvements in long-term survival, particularly because these factors have also encouraged the treatment of older patients with greater comorbidity. The aim of this study was to quantify how 5 year survival after elective AAA repair has changed over time.

Methods

A systematic review was performed identifying studies reporting 5 year survival after elective infrarenal AAA repair. An electronic search of the Embase and Medline databases was conducted to January 2014. Thirty-six studies, 60 study arms, and 107,814 patients were identified. Meta-analyses were conducted to determine 5 year survival and to report whether 5 year survival changed over time.

Results

Five-year survival was 69% (95% CI 67 to 71%, I² = 87%). Meta-regression on study midpoint showed no improvement in 5 year survival over the period 1969–2011 (log OR −0.001, 95% CI −0.014–0.012). Larger average aneurysm diameter was associated with poorer 5 year survival (adjusted log OR −0.058, 95% CI −0.095 to −0.021, I² = 85%). Older average patient age at surgery was associated with poorer 5 year survival (adjusted log OR −0.118, 95% CI −0.142 to −0.094, I² = 70%). After adjusting for average patient age, an improvement in 5 year survival over the period that these data spanned was obtained (adjusted log OR 0.027, 95% CI 0.012 to 0.042).

Conclusion

Five-year survival remains poor after elective AAA repair despite advances in short-term outcomes and is associated with AAA diameter and patient age at the time of surgery. Age-adjusted survival appears to have improved; however, this cohort as a whole continues to have poor long-term survival. Research in this field should attempt to improve the life expectancy of patients with repaired AAA and to optimise patient selection.

A Retrospective Analysis of Comparison of General Versus Regional Anaesthesia for Endovascular Repair of Abdominal Aortic Aneurysm

OBJECTIVE

The aim of this study is to compare general anaesthesia (GA) versus regional anaesthesia (RA) for endovascular aneurysm repair (EVAR).

METHODS

We analysed the files of 89 patients between August 2010-August 2012 who underwent elective EVAR retrospectively.

RESULTS

We performed RA for 32 patients (36%) and GA for 57 patients (64%). The operations were completed successfully in both groups and did not require conventional surgery. The mean age of the patients was 71.5±7 (range 50-88 years). RA was preferred more than GA in the presence of advanced-stage chronic obstructive pulmonary disease statistically (p=0.032). The usage of vasodilator drug and atropine was found to be higher in the GA group than the RA group in the intraoperative period (p=0.001 and p=0.01, respectively). The intensive care unit (ICU) was necessary for 5 patients in the RA group (16%) and 13 patients for the GA group (23%) postoperatively (p=0.301). The median ICU stay in the RA group was 2 hours and 4.4 hours in the GA group (p=0.114). The median hospital stay was 2.63±1.91 days in the RA group and 2.04±1.16 days in the GA group, with no statistically significant difference between groups (p=0.120). There was no mortality of patients in either group for the peroperative period and the 30-day follow-up period.

CONCLUSION

Our present study suggests that patient characteristics are more important than the anaesthetic method on the outcomes of EVAR.

Ultrasonographic Surveillance of Abdominal Aortic Endovascular Aneurysm Stent Graft Repair in a Dedicated Vascular Laboratory

Surveillance following abdominal aortic endovascular aneurysm repair (EVAR) is imperative to confirm graft patency, analyze residual sac size (RSS), and evaluate for complications. This retrospective study evaluated ultrasonographic (US) surveillance after EVAR compared to computed tomography (CT). US was done by 1 of 11 experienced registered technologists. US was ordered for surveillance more frequently than CT, with a ratio of 4:1. Compared to CT, US endoleak evaluations were 74% sensitive and 76% specific with a 63% positive predictive value and 84% negative predictive value. However, 11 CT scans were likely false negatives, and 1 CT was a false positive. For true positives that stated endoleak type, there was a 93% agreement between the type on US and CT. US had a 75% accuracy for RSS (95% CI, −1.02 to 1.16). These data support the use of US along with clinical symptoms as a first-line surveillance program after EVAR and are widely applicable to the majority of vascular laboratories that employ multiple registered vascular technologists. The adaptation of increased US surveillance would decrease the number of CT scans, thereby significantly reducing cost and radiation/contrast exposure to patients.