Measurement of Free Radicals Using Electron Paramagnetic Resonance Spectroscopy During Open Aorto-Iliac Arterial Reconstruction
Wacław Majewski, Ryszard Krzyminiewski, Michał Stanisić, Maria Iskra, Zbigniew Krasiński, Marek Nowak, Bernadeta Dobosz
Department of General and Vascular Surgery, Poznań University of Medical Sciences, Poznań, Poland
Med Sci Monit 2014; 20:2453-2460
Aortic cross-clamping during abdominal aortic aneurysm (AAA) open repair leads to development of ischemia-reperfusion injury. Electron paramagnetic resonance spectroscopy (EPR) spin-trapping is a valuable method of direct measurement of free radicals.
The objective of the study was to evaluate the results of EPR as a direct method of free radical measurement and degree of inflammatory response in open operative treatment of patients with AAA and aorto-iliac occlusive disease (AIOD).
Material and Methods: The study was performed on a group of 32 patients with AAA and 25 patients with AIOD scheduled for open repair. Peripheral venous blood for EPR spectroscopy and for SOD, GPx, ox-LDL, Il-6, TNF-alfa, CRP, and HO-1 were harvested. Selected parameters were established accordingly to specified EPR and immunohistochemical methods and analyzed between groups by Mann-Whitney U test and Wilcoxon matched-pairs signed-ranks test with Bonferroni correction.
Results: Free radicals level was correlated with the time of the aortic cross-clamping after the reperfusion of he first and second leg in AAA (r=0.7; r=0.47). ox-LDL in AAA decreased 5 min after reperfusion of the first leg (32.99 U/L, range: 14.09–77.12) and 5 min after reperfusion of the second leg (26.75 U/L, range: 11.56–82.12) and 24 h after the operation (25.85 U/L, range: 14.29–49.70). HO-1concentration increased to above the level before intervention 24 h after surgery. The activities of GPx and SOD decreased 5 min after the first-leg reperfusion in AAA. Twenty-four hours after surgery, inflammatory markers increased in AAA to CRP was 14.76 ml/l (0.23–38.55), IL-6 was 141.22 pg/ml (84.3–591.03), TNF-alfa was 6.82 pg/ml (1.76–80.01) and AIOD: CRP was 18.44 mg/l (2.56–33.14), IL-6: 184.1 pg/ml (128.46–448.03), TNF-alfa was 7.74 pg/ml (1.74–74.74).
Conclusions: EPR spin-trapping demonstrates temporarily elevated level of free radicals in early phase of reperfusion, leading to decrease antioxidants in AAA. Elevated free radical levels decreased 24 h after surgery due to various endogenous antioxidants and therapies.
Keywords: Aortic Aneurysm, Abdominal - surgery, Aorta - surgery, Electron Spin Resonance Spectroscopy - methods, Free Radicals - metabolism, Glutathione Peroxidase - metabolism, Heme Oxygenase-1 - metabolism, Ilium - surgery, Malondialdehyde - blood, Reconstructive Surgical Procedures, Superoxide Dismutase - metabolism, Vascular Surgical Procedures