Background: The clamping and declamping of the aorta during elective abdominal aneurysmectomy lead to severe disturbances in blood circulation in different organs and in the brain especially.
The aim of this pilot study is an assessment of the negative influence of clamping and declamping on the aorta on the brain function during elective surgery of infra-aortic aneurysms.
Material and methods: An investigation was performed on a 16 patient group with infrarenal aortic aneurysm who were treated electively. We estimated changes in blood concentration of S-100 protein received from the jugular vein in several samples after the clamping and declamping of the aorta.
Results: In 8 cases we observed progressive growth of S-100 concentration after clamping of aorta in following samples. In all of them it was statistically significant. In the next 3 cases we observed a violent growth in S-100 concentration in the first minute after clamping and progressive decreasing of its concentration in the following samples. Only in one patient we observed normalization of S-100 concentration after a 10 minute period, to the level observed before clamping of the aorta which was very interesting. In 5 cases statistically significant changes in the S-100 concentration were not observed. In next three cases investigations were extended for ten minutes after the declamping of the aorta. In these cases was an increase in the concentration of S-100 in the following samples observed - in respective to the first blood sample examination results. In two cases from this group the following augmentation of S-100 was observed. Only one patient had constant concentration of S-100 during all time of observation.
Conclusions: 1. Changes in S-100 protein concentration are high related to blood pressure and indirectly point to the intensification of brain injury during infra-renal aneurysm repair. 2. Both the growth of blood pressure at the time of clamping and the sequence which falls after declamping result in an unfavorable effect onto the central nervous system. So at the time of these maneuvers blood pressure changes should be minimalised. 3. There is no possibility to measure clinical signs and total brain injury at the time of clamping and declamping of aorta on the basis of changes in S-100 protein blood concentration.