Chapter 144 - Infected arterial aneurysms Flashcards
Mycotic aneurysm term origin
Osler 1885 to describe mushroom like eccentric saccular configuration
4 classes of infected arterial aneurysms
1) Microbial arteritis witha neurysm formation due to non-cardiac origin bacteremia 2) Post-traumatic infected pseudoaneurysm, illicit drug 3) Infection of pre-existing atherosclerotic aneurysm 4) infected aneurysm from septic emboli
Clinical characteristics of infected aneurysms based on 4 classes and common baceriology
TABLE 144.1
Microbial arteritis mechanism
1) bacterial seeding in arterial irregularity (atherosclerosis, coarctation, PDA) 2) suppuration and local perf and pseudoaneurysm 3) aorta most common
Risk factors of microbial arteritis mechanism
1) DM 2) cirrhosis 3) HD 4) post-transplant immunosuppression 5) HIV 6) alcoholism 7) glucocorticoid therapy 8) chemotherapy 9) malignancy
Post-traumatic infected pseudoaneurysm location
1) femoral (access and closure device) 2) carotid 3) brachial 4) external iliac 5) subclavian
Percent of infected arterial aneurysm due to emboli
10%
Most common organism for infected aneurysm
1) Staphlococcus sp. 28-71% 2) Samonella 15-24% (choleraesuis and enteritidis) 3) Streptococcus < 10%
Percentage of blood culture positive in infected aneurysms
50-85% 76% positive aneurysm tissue
Organism associated with illicit drug use
MRSA
Clostridium septicum aortitis association
1) GI or hematological malignancy 2) rupture and death 64-100%
Fungal infection in infected aneurysms - organisms
1) Candida 2) Cryptococcus 3) Aspergillus 4) Pseudallescheria boydii
Other rare causes of infected aneurysms
1) Treponema pallidum (Syphilis) 2) mycobacterium 3) Bacillus Calmette-Guerin (bovine TB bacillus) used for intravesical treatment for superficial bladder cancer can cause aneurysm
Angiographic findings of infected aneurysm
1) saccular 2) multi-lobulated 3) adjacent soft tissue inflammation and fluid 4) air within aneurysm 5) air in aneurysm wall 6) signs of rupture 7) rapid enlargement
Antibiotic regimen in infected aneurysm therapy
1) Broad spectrum 2) 6 weeks post-surgery
Aortic portions to be infected - percentage
Infrarenal 40% distal thoracic 16% thoracoabdominal 16% paravisceral 13% juxtarenal 4%
Exclusion bypass by Kiefer - describe
Ascending aorta to infrarenal aorta bypass with prosthetic graft Staple close distal aortic arch and supraceliar aorta
Mortality in med-managed thoracoabdominal infected aneurysm
85%
Surgical mortality of infected AAA
15-38%
Cryograft for infected aorta survival at 1 year and 5 year along
1 year 75% 5 year 51%
Allograft reconstruction complications in infected aortic aneurysms
1) peri-anastomotic hemorrhage 2) graft limb occlusion 3) pseudoaneurysm
Re infection rates in antibiotic soaked Dacron grafts
4-22%
1, 5 and 10 year mortality after rifampin soaked graft in infected aneurysms
1 year 85% 5 year 59% 10 year 40%
NAIS described first by
Clagett
Reinfection after NAIS for infected aorta
2%
Primary patency of NAIS
2 year 87% 5 year 82% Primary assisted 94-96%
Mortality of NAIS in hospital and 5 year
10% 30 day 60% 5 year
Rate of fasciotomy after NAIS
12% higher in previous GSV harvest
Chronic venous insufficiency after NAIS
15%
Rate of aortic stump blow out after infection repair
12%
5 year patency of Ax-fem graft
70%
Rate of infection in ax-fem
6-20%
Mortality of aortic-aero-digestive fistula
67%
Rate of infection after femoral perc procedure
1%
Rate of amputation if CFA, PFA, SFA ligated in infection
33% Single artery ligation does not result in amputation
Rate of neurologic events after ligating ICA
20-60%
Stump pressure suggesting safe ICA ligation
> 70 mmHg
Rate of synchronous infected aneurysm in the presence of an SMA aneurysm
19%
Rupture rate in SMA aneurysms
38-50%
Mortality after SMA aneurysm rupture
30%
