Sorelius, Karl, Wanhainen, Anders, Furebring, Mia, Mani, Kevin, Resch, T., Hultgren, R., Wahlgren, C. M., Roos, H., Ojersjo, A., Lindström, David, Vaccarino, R., Arvidsson, B., Bilos, L., Pirouzram, A., Arnerlov, C., Simo, G., Svensson, M., Magnusson, J., Astrand, H., Palm, M., Holsti, M., Mellander, S., Korman, D., Djavani-Gidlund, K., Huss, M., Bertszel, A., Docter, M., Drott, C., Nelzen, O., Wetterling, T., Chu, M., Gilgen, N-P, Gillgren, P., Sorelius, Karl, Wanhainen, Anders, Furebring, Mia, Mani, Kevin, Resch, T., Hultgren, R., Wahlgren, C. M., Roos, H., Ojersjo, A., Lindström, David, Vaccarino, R., Arvidsson, B., Bilos, L., Pirouzram, A., Arnerlov, C., Simo, G., Svensson, M., Magnusson, J., Astrand, H., Palm, M., Holsti, M., Mellander, S., Korman, D., Djavani-Gidlund, K., Huss, M., Bertszel, A., Docter, M., Drott, C., Nelzen, O., Wetterling, T., Chu, M., Gilgen, N-P, and Gillgren, P.
Objective: The aim was to describe the microbiology of surgically treated infective native (mycotic) aortic aneurysms (INAAs), and associated survival and development of infection-related complications (IRCs). Methods: Data were pooled from 2 nationwide studies on surgically treated patients with INAAs in Sweden, between 1994 - 2016. Patients were grouped and analyzed according to culture results: 1) Staphylococcus aureus, 2) Streptococcus species (sp.), 3) Salmonella sp., 4) Enterococcus sp., 5) Gram-negative intestinal bacteria, 6) Other sp. (all other species found in culture), and 7) Negative cultures. Results: A sum of 182 patients were included, mean age 71 years (standard deviation; SD: 8.9). The median follow-up was 50.3 months (range 0 - 360). 128 (70.3%) patients had positive blood and/or tissue culture; Staphylococcus aureus n = 38 (20.9%), Streptococcus sp. n = 37 (20.3%), Salmonella sp. n = 19 (10.4%), Enterococcus sp. n = 16 (8.8%), Gram-negative intestinal bacteria n = 6, (3.3%), Other sp. n = 12 (6.6%) and Negative cultures n = 54 (29.7%). The estimated survival for the largest groups at 2-years after surgery was: Staphylococcus aureus 62% (95% Confidence interval 53.9 - 70.1), Streptococcus sp. 74.7% (67.4 - 82.0), Salmonella sp. 73.7% (63.6 - 83.8), Enterococcus sp. 61.9% (49.6 - 74.2), and Negative cultures 89.8% (85.5 - 94.1), P =.051. There were 37 IRCs (20.3%), and 19 (51.4%) were fatal, the frequency was insignificant between the groups. The majority of IRCs, 30/37 (81%), developed during the first postoperative year. Conclusion: In this assessment of microbiological findings of INAAs in Sweden, 50% of the pathogens were Staphylococcus aureus, Streptococcus sp., or Salmonella sp.. The overall 20%-frequency of IRCs, and its association with high mortality, motivates long-term antibiotic treatment regardless of microbial findings.