Table 2. Postoperative mortality and 30-day morbidity of four groups.

Operative characteristic	Group I(N = 72)	Group II(N = 23)	Group III(N = 45)	Group IV(N = 16)	P
Mortality	13(18.1%)	9(39.1%)	12(26.7%)	1(6.3%)	0.062
Group I		0.037*	0.269*	0.450*
Group II			0.293*	0.028*
Group III				0.153*
Stroke	10(13.9%)	8(34.8%)	16(35.6%)	1(6.3%)	0.008
Group I		0.035*	0.006*	0.681*
Group II			0.950*	0.056*
Group III				0.027*
Acute kidney injury	16(22.2%)	7(30.4%)	13(28.9%)	4(25.0%)	0.808
Ischemic bowel	2(2.8%)	0(0)	2(4.4%)	0(0)	0.464
Re-exploration for bleeding	7(9.7%)	2(8.7%)	8(17.8%)	0(0)	0.122
Acute ischemia limb	2 (2.8%)	0	0	0	0.373
Respiratory failure	5 (6.9%)	5 (21.7%)	7 (15.6%)	2 (12.5%)	0.237
Heart failure	4 (5.6%)	1 (4.3%)	4 (8.9%)	0	0.441
Ischemic colitis	1 (1.4%)	0	1 (2.2%)	0	0.736
Vocal cord palsy	1 (1.4%)	0	2 (4.4%)	0	0.432
Hepatic failure	1 (1.4%)	1 (4.3%)	1 (2.2%)	0	0.731
Mediastinitis	1 (1.4%)	0	2 (4.4%)	0	0.432
Hospital stay	25.9±33.5	39.0±53.9	33.8±29.7	24.1±17.2	0.323

* p-value for individual Chi-square test.