Arterial Aneurysm Repair Outcomes: Low BSI Incidence, High Long-Term Mortality

Although the incidence of bloodstream infection (BSI) is low in patients who undergo arterial aneurysm repair, long-term mortality rates are high among those who develop BSIs. These study findings were published in Open Forum Infectious Diseases.

Researchers performed a population-based study to examine the incidence and outcomes of BSI following arterial aneurysm repair. Eligible patients included adults (N=643) who underwent the procedure at the Mayo Clinic in Rochester, Minnesota, between 2010 and 2020. Arterial aneurysm repair was defined as the use of a graft during open surgical repair or stent placement during endovascular repair for arterial aneurysmal dilation. Time to BSI was considered the duration between index aneurysm repair and first positive blood culture result. The cumulative risk for BSI was compared between patients who underwent open surgical vs endovascular repair procedures.

A total of 706 aneurysm repair procedures were performed among the study population, of which 290 (41.1%) were open surgical repairs and 416 (58.9%) were endovascular repairs.

Among all patients, the median age was 74.1 (IQR, 66.3-80.5) years, 79.5% were men, 96.9% were White, the median BMI was 28.9 (IQR, 25.7-33.0) kg/m², 71.7% had coronary artery disease, 61.6% had heart valve disease, and 15.0% previously underwent aneurysm repair procedures.

A total of 42 BSI episodes were observed within a median follow-up period of 4.2 years, of which 25 occurred after open surgical repair and 17 after endovascular repair. The median time from aneurysm repair to first BSI episode was 3.1 (IQR, 0.6-6.4) years. Overall, 36 (85.7%) patients had community-onset BSIs and 6 (14.3%) had nosocomial BSIs.

The BSI incidence per 1000 procedure-years was higher following open surgical repair (incidence rate [IR], 16.4; 95% CI, 10.6-24.2) vs endovascular repair (IR, 10.8; 95% CI, 6.3-17.4).

Patients who underwent open surgical vs endovascular repair procedures were more likely to develop BSIs (cumulative 5-year IR, 5.8% vs 4.0%; subdistribution hazard ratio, 1.86; 95% CI, 1.00-3.49).

A total of 39 (92.9%) patients developed monomicrobial BSIs, of whom 21 were infected with gram-negative organisms and 18 with gram-positive organisms. The most commonly isolated gram-negative and gram-positive pathogens were Streptococcus species and Escherichia coli, respectively.

Of 33 patients who were evaluated for vascular graft infection following incident BSI, 10 (30.3%) tested positive. All patients with vascular graft infection were diagnosed within 2 weeks of BSI occurrence, and the median time from index repair to first BSI event was 1.5 (IQR, 1.0-4.6) years.

Mortality occurred among 22 patients who developed BSIs within a median follow-up period of 2.7 years, with mortality attributed to BSI in 6 (27.3%) of these patients. The cumulative all-cause mortality rate among patients who developed BSIs was 12.1% at 30 days, 22.5% at 1 year, 55.8% at 3 years, and 76.8% at 5 years.

Advanced age and comorbidities potentially contributed to the high rate of mortality observed among the population, the researchers noted.

The major limitations of this study include the retrospective design and the low number of BSI diagnoses.

“As the epidemiology of vascular reconstructive surgery continues to evolve, the incidence of BSI and VGI [vascular graft infection] following aneurysm repair is expected to change,” the researchers concluded.

Disclosures: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.