Рентгенология & Радиология, 2012, LI 107-113

Variations of Willis circle, important for cerebral protection in aortic surgery – comparing 16- and 320-slices computed tomography angiography
V. Papantchev, V. Stoinova, D. Todorova-Papantcheva, V. Groudeva, A. Paloff, D. Hinova-Palova, S. Hristov, A. Alexandrov, M. Goshev, D. Nikolov, D. Petkov, G. Nachev,W. Ovtscharoff

Abstract.

Unilateral selective cerebral perfusion (uSCP) is a method for cerebral protection during arch replacement. Some variations of circle of Willis (CoW) could vitiate its protective effect.The aim of present work is to compare the results from CTangiography of the CoW, obtained with 16- and 320-slices’multidetectors CT scanners. Two-hundred patients were divided in to two groups:Group 1 – 105 patients, examined with 16 Slice MDCT between January 2008 and December 2008, and Group 2 – 105 patients, examined with 320 slices MDC between January 2010 and March 2012. The results from both groups
were compared, using SPSS 16.0In both groups seven evident configurations of CoW, thatcould cause hypoperfusion during uSCP, were found. Their
overall frequency was 66.67% (70/105) in Group 1 and 75.2% (79/105) in Group 2 respectively, but these difference doesnot reach statistical significance (Р>0.05). No statistically significant difference in frequency of 7 CoW types betweengroups was found between groups (P>0.05). There was statistic significant difference between groups in frequencyof CoW segments described as hypoplastic (Р<0.001) or aplastic (Р<0.001). Our present study supports the need of extensivepreoperative examination and meticulous intraoperativemonitoring of cerebral perfusion during uSCP Because of itshigher resolution 16 Slice MDCT allows better identification of hypolastic and aplastic segments of variant circles.

Key words: CEREBRAL PROTECTION. AORTIC SURGERY VARIATION WILLIS CIRCLE