Table 2.

Main operation-related data for different years

Index/year	2015 (n = 88)	2016 (n = 279)	2017 (n = 351)	2018 (n = 380)	F /x2	P value
Age (yr)	51.97 ± 11.35	49.34 ± 12.60	49.88 ± 13.05	50.95 ± 13.58	1.415	-
Sex (M/F)	55/34	159/120	203/148	239/141	3.134	-
LLR types
Local resection	2.27% (2/88)	35.13% (98/279)	39.60% (139/351)	36.58% (139/380)	45.306	< 0.01b
Anatomical resection	23.86% (21/88)	8.24% (23/279)	11.40% (40/351)	9.47% (36/380)	18.096	< 0.01b
Right hemi-hepatectomy	14.77% (13/88)	9.32% (26/279)	7.41% (26/351)	5.79% (22/380)	8.903	< 0.05a
Pre-operative ALT (U/L)	36.82 ± 28.17	36.67 ± 20.05	35.71 ± 25.37	43.58 ± 33.39	1.667	-
Pre-operative TBL (umol/L)	14.76 ± 5.81	13.55 ± 5.83	13.51 ± 6.21	14.63 ± 7.78	2.519	-
Inpatient time (d)	12.48 ± 6.23	11.77 ± 6.67	9.53± 5.04	8.03 ± 3.20	37.583	< 0.01b
Post operative inpatient time (d)	7.98 ± 5.00	6.87 ± 4.82	5.39 ± 3.70	4.70 ± 2.22	29.781	< 0.01b
Hospitalization expense (RMB, Yuan)	48708.55 ± 20939.76	47280.53 ± 17249.26	46468.97 ± 35172.25	43016.31 ± 14509.30	2.448	-
Operation time (min)	257.98 ± 114.25	236.85 ± 100.40	203.81 ± 85.83	205.61 ± 99.54	12.596	< 0.01b
Blood loss (mL)	275.65 ± 39.19	245.53 ± 19.10	232.54 ± 12.34	241.84 ± 20.32	0.413	-
Post operative ALT (U/L)	355.19 ± 44.44	288.22 ± 19.17	237.16 ± 10.66	251.93 ± 16.03	5.262	< 0.01b
Post operative TBL (umol/L)	36.07 ± 3.49	27.86 ± 1.01	28.31 ± 0.92	24.61 ± 1.02	7.443	< 0.01b
Mortality of 90 d	2.27% (2/88)	0.36% (1/279)	0 (0/351)	0 (0/380)	14.989	< 0.01b
Complications	13.64% (12/88)	13.98% (39/279)	7.98% (28/351)	5.79% (22/380)	15.621	< 0.01b
Drainage (mL)	133.12 ± 20.44	111.88 ± 7.62	103.10 ± 6.63	82.44 ± 8.27	3.433	< 0.05a
Conversion rate	0 (0/88)	2.15% (6/279)	2.56% (9/351)	1.32% (5/380)	3.427	-

^a P < 0.05.

^b P < 0.01.

ALT: Alanine transaminase; LLR: Laparoscopic liver resection; TBL: Total bilirubin.