Porcine model of ruptured abdominal aortic aneurysm repair.
OBJECTIVES
To validate a porcine model of ruptured abdominal aortic aneurysm (rAAA) repair.


DESIGN
Experimental study.


METHODS
Ten experimental and five sham-operated pigs were studied. Instrumentation for cardiac output (CO) measurement, regional blood flow (renal-REN and portal-PORT) and blood sampling (inferior vena cava (IVC), renal and portal vein) was done. Microcirculation was visualised sublingually and in ileostoma.


PROTOCOL
simulation of rAAA with bleeding (mean arterial pressure (MAP) 45 mmHg) and increased abdominal pressure (25 mmHg) for 4 h; 2 h of infrarenal clamp with shed blood retransfusion; 11 h of post-surgery care.


RESULTS
Six experimental pigs completed the protocol and are presented. Bleeding decreased CO to 95%, PORT to 80% and REN to 10% of baseline. From clamping on CO and PORT increased above baseline whereas REN (47%) with creatinine clearance remained compromised till the end. Microcirculation was affected more in ileum than sublingually. Approximately threefold increase in cytokines (tumour necrosis factor-α (TNF-alpha), interleukin (IL)-6 and IL-10) and oxidative stress markers (thiobarbituric acid-reactive substances (TBARs) and 4-hydroxy-2-trans-nonenal (HNE) was observed. Only mild increase in IL-6 and TBARs was observed in sham-operated animals. Organ histology did not reveal differences between groups.


CONCLUSIONS
This near-lethal model of rAAA induced expected severe deterioration of haemodynamics and metabolism accompanied with a moderate inflammatory and oxidative stress response.