Table 2.

Incidence of variations in the morphology of the arteries that constituted the CoW grouped according to age in South African patients.

Age	Segments of CoW and variations
	ACA A1 (n = 239)								ACA A2 (n = 239)												MCA (n = 239)				PCA (n = 239)
	AB (%)		FE (%)		HY (%)		TY (%)		AB (%)		AZ (%)		FE (%)		HY (%)		TR (%)		TY (%)		HY (%)		TY (%)		HY (%)		TY (%)
	R	L	R	L	R	L	R	L	R	L	R	L	R	L	R	L	R	L	R	L	R	L	R	L	R	L	R	L
19–29	0	0	50	0	50	50	0	50	0	0	0	0	0	0	50	0	0	0	50	100	50	0	50	100	0	0	100	100
30–39	11.76	5.88	0	0	29.41	29.41	58.82	58.82	0	0	5.9	5.9	0	0	41.2	29.4	5.9	5.9	41.2	52.9	17.65	11.76	82.35	88.24	41.18	35.29	52.94	58.82
40–49	0	0	0	0	50	35	50	65	0	0	5.0	5.0	0	0	25	30.0	0	0	65	60.0	10	10	90	90	40	40	55	60
50–59	4.76	2.38	2.38	0	35.71	21.43	52.38	71.43	0	0	0	0	2.4	2.4	31	28.6	0	0	64.3	66.7	11.90	9.52	88.10	90.47	30.95	35.71	66.67	64.29
60–69	6.82	0	0	2.27	29.55	29.55	59.09	63.64	0	0	0	0	0	0	25	31.8	0	0	75	68.2	13.64	13.64	86.36	86.36	22.73	29.55	70.45	68.18
70–79	10.77	3.08	0	1.54	38.46	35.38	49.23	58.46	0	0	1.5	1.5	1.5	1.5	27.7	18.5	0	0	66.2	75.4	0	1.54	98.46	98.46	27.69	29.23	69.23	67.69
80–89	7.14	2.38	0	2.38	11.90	19.05	80.95	76.19	2.4	2.4	0	0	2.4	2.4	21.4	23.8	2.4	2.4	71.4	69.0	4.76	2.5	95.24	95.24	9.52	19.05	90.48	80.95
90–105	0	14.29	0	0	0	28.57	100	57.14	0	0	0	0	0	0	0	0	14.3	14.3	85.7	85.7	0	0	100	100	42.86	28.57	57.14	71.43
p-value	R: p < 0,001* L: p = 0.921								R: p = 0.052 L: p = 0.581												R: p = 0.154 L: p = 0.430				R: p = 0. 233 L: p = 0.765

*p-value ≤ 0.05 was considered statistically significant.

AB absence, TY typical, HY hypoplasia, AZ azygous, TR triple, FE fenestration, R right, L left, n sample size.