Experimental evaluation of retrograde cerebral perfusion by single photon emission computed tomography technique (SPECT)

Background. Protection of the brain is of vital importance during aortic ar ch aneurysms. In this study efficiency of retrograde cerebral perfusion was evaluated with the use of single photon emission computed tomography techn ique (SPECT) by using Tc-99m hexamethylpropylene amine oxime (HMPAO). Methods. Four animals were used. The internal maxillary vein was the site o f retrograde cerebral perfusion. The animals were studied after the heart r ate and respiration were stopped with the use of the high dose drug adminis tration and the brain was pet-fused with cold Ringer's lactated solution. A fter this procedure, Tc-99m HMPAO-SPECT study was performed. Results. In one animal we did not get any cerebral image because of the com petent venous valve in the internal maxillary vein. In the remaining animal s, normal brain perfusion was achieved. Conclusions. Tc-99m HMPAO-SPECT study documented that blood flow via the re trograde way meets the metabolic demand of the brain. Retrograde delivery o f Tc-99m HMPAO did not conclude any poorly perfused area in the brain when in given both sides and all parts of the brain can be effectively perfused by cerebral venous system in hypothermic conditions.