The Association Between Frailty and Outcomes Following Ruptured Abdominal Aortic Aneurysm Repair

BACKGROUND

Endovascular aortic repair (EVAR) is a less invasive method than the more physiologically stressful open surgical repair (OSR) for patients with anatomically appropriate abdominal aortic aneurysm (AAA). Early postoperative outcomes are associated with both patients' physiologic reserve and the physiologic stresses of the surgical intervention. Among frail patients with reduced physiologic reserve, the stress of an aortic rupture in combination with the stress of an operative repair are less well tolerated, raising the risk of complications and mortality. This study aims to evaluate the difference in association between frailty and outcomes among patients undergoing minimally invasive EVAR and the physiologically more stressful OSR for ruptured AAA (rAAA).

STUDY DESIGN

Our retrospective cohort study included adults undergoing rAAA repair in the Vascular Quality Initiative from 2010 to 2022. The validated Risk Analysis Index (RAI; robust≤20, normal 21-29, frail 30-39, very frail≥40) quantified frailty. The association between the primary outcome of 1-year mortality and frailty status as well as repair type were compared using multivariable Cox models generating adjusted hazard ratios (aHR) with 95% confidence intervals (95%CI). Interaction terms evaluated the association's moderation.

RESULTS

We identified 5,806 patients (age 72±9 years; 77% male; EVAR 65%; robust 6%; normal 48%; frail 36%; very frail 10%) with a 53% observed 1-year mortality rate following rAAA repair. OSR [aHR = 1.43 (95%CI 1.19-1.73)] was associated with increased 1-year mortality when compared to EVAR. Increasing frailty status [frail aHR = 1.26 (95%CI 1.00-1.59); very frail aHR =1.64 (95%CI 1.26-2.13)] was associated with increased 1-year mortality, which was moderated by repair type (P-interaction<.05). OSR was associated with increased 1-year mortality in normal [aHR = 1.49 (95%CI 1.20-1.87)] and frail [aHR = 1.51 (95%CI 1.20-1.89)], but not among robust [aHR = 0.88 (95%CI 0.59-1.32)] and very frail [aHR = 1.29 (95%CI 0.97-1.72)] patients.

CONCLUSION

Frailty and OSR were associated with increased adjusted risk of 1-year mortality following rAAA repair. Among normal and frail patients, OSR was associated with an increased adjusted risk of 1-year mortality when compared to EVAR. However, there was no difference between OSR and EVAR among robust patients who can well-tolerate the stress of OSR and among very frail patients who are unable to withstand the surgical stress from rAAA regardless of repair type.

Characteristics and One-year Outcomes of Patients with Rupture of Small Abdominal Aortic Aneurysms

OBJECTIVES

Rupture of abdominal aortic aneurysms (rAAA) is typically associated with large sac diameter, however some patients experience rupture before reaching operative thresholds for elective repair. We aim to investigate the characteristics and outcomes of patients who experience small rAAA.

METHODS

The Vascular Quality Initiative database for open AAA repair and endovascular aneurysm repair (EVAR) from 2003-2020 were reviewed for all rAAA cases. Based on the 2018 Society for Vascular Surgery guidelines on operative size thresholds for elective repair, patients with infrarenal aneurysms <5.0cm in women or <5.5cm in men were categorized as "small rAAA." Patients who met operative thresholds or had a concomitant iliac diameter ≥3.5cm were categorized as "large rAAA.". Patient characteristics and perioperative as well as long-term outcomes were compared via univariate regression. Inverse probability of treatment weighting (IPTW) using propensity scores was employed to examine the relationship between rAAA size and adverse outcomes.

RESULTS

There were 3,962 cases that met inclusion criteria, with 12.2% small rAAA. The mean aneurysm diameter was 42.3mm and 78.5mm in the small and large rAAA groups, respectively. Patients in the small rAAA group were significantly more likely to be younger, African American, have lower BMI, and had significantly higher rates of hypertension. Small rAAA were more likely to be repaired via EVAR (p=0.001). Hypotension was significantly less likely in patients with small rAAA (p<0.001). Rates of perioperative myocardial infarction (p<0.001), total morbidity (p<0.004) and mortality (p<0.001) were significantly higher for large rAAA cases. After propensity matching, there was no significant difference in mortality between the 2 groups, but smaller rAAA was associated with lower rates of MI (OR=0.50[0.31-0.82]). On long-term follow up, no difference in mortality was noted between the two groups.

CONCLUSIONS

Patients presenting with small rAAA represent 12.2% of all rAAA and are more likely to be African American. Small rAAA is associated with similar risk of perioperative and long-term mortality compared to rupture at larger size after risk adjustment.