Liver resection for hepatocellular carcinoma using a microwave tissue coagulator: Experience of 1118 cases

Table 4 Subgroup analyses of perioperative variables

	Time period		P value	Presence of cirrhosis		P value	Operative procedure		P value
	1990-2003	2004-2013		LC	Non-LC		AR	NAR
n	511	607		656	462		275	843
Preoperative factors
Presence of cirrhosis (%)	64	54	< 0.01	NA	NA		38	65	< 0.01
Tumor > 2 cm (%)	51	58	0.02	48	66	< 0.01	83	46
Intraoperative results
Operative time (min)	175	155	< 0.01	160	173	< 0.01	220	153	< 0.01
Intraoperative blood loss (mL)	272	242	0.11	250	270	0.38	528	203	< 0.01
Anatomical resection	23	25	1.00	16	37	< 0.01	NA	NA
R1 resection (%)	12	11	0.78	12	10	0.39	9	12	0.33
Intraoperative BT required (%)	45	10	< 0.01	29	21	< 0.01	34	5	< 0.01
Red blood cell transfusion (%)	8	7	0.18	8	7	0.73	16	5	< 0.01
Plasma transfusion (%)	44	7	< 0.01	27	19	< 0.01	31	21	< 0.01
Postoperative results
Postoperative BT required	56	12	< 0.01	37	24	< 0.01	39	29	< 0.01
Red blood cell transfusion	15	4	< 0.01	11	7	0.04	15	7	< 0.01
Plasma transfusion	55	10	< 0.01	36	23	< 0.01	38	28	< 0.01
All complications1	18	14	0.08	17	16	0.63	20	15	0.10
Death	1.4	0.5	0.20	1.4	0.2	0.053	1.4	0.7	0.27
Bile leakage	3.7	2.3	0.21	2.3	3.9	0.72	4.4	2.5	0.15
Intra-abdominal abscess formation	4.3	2.4	0.10	3.2	3.5	0.06	4.4	3.0	0.25

¹Perioperative blood transfusion was excluded. BT: Blood transfusion; LC: Liver cirrhosis; AR: Anatomical resection; NAR: Non-anatomical resection R1, positive resection margin in histological specimen.