Table 4. Mann-Whitney U test of differences between the study and the comparison group.

	Rank—b	Rank—p	U	Z	p
Serum VEGF-A before surgery [pg/ml]	2872.50	1978.50	703.50	3.52492	0.00042

b, study group; p, comparison group; VEGF-A, vascular endothelial growth factor—A.