Laparoscopic liver resection utilizing the ventral avascular area of the inferior vena cava: A retrospective cohort study

Table 1 Baseline characteristics of the patients, n (%)

	Overall (n = 256)	Conventional LLR (n = 150)	Novel LLR (n = 106)	P value
Age, year	62.88 ± 10.52	62.43 ± 11.07	63.52 ± 9.71	0.414
Sex				1.000
Male	130 (50.8)	76 (50.7)	54 (50.9)
Female	126 (49.2)	74 (49.3)	52 (49.1)
Pathological types				0.707
HCC	176 (68.8)	105 (70.0)	71 (67.0)
ICC	80 (31.2)	45 (30.0)	35 (33.0)
BMI, kg/m2	23.77 ± 4.30	23.90 ± 4.29	23.59 ± 4.33	0.567
Hepatitis B/C virus				0.119
B	212 (82.8)	130 (86.7)	82 (77.4)
C	9 (3.5)	5 (3.3)	4 (3.8)
None	35 (13.7)	15 (10.0)	20 (18.9)
Cirrhosis				0.694
No	99 (38.7)	56 (37.3)	43 (40.6)
Yes	157 (61.3)	94 (62.7)	63 (59.4)
Comorbidities				0.729
No	118 (46.1)	71 (47.3)	47 (44.3)
Yes	138 (53.9)	79 (52.7)	59 (55.7)
BCLC				< 0.001
0	22 (8.6)	21 (14.0)	1 (0.9)
A	230 (89.8)	129 (86.0)	101 (95.3)
B	2 (0.8)	0 (0.0)	2 (1.9)
C	2 (0.8)	0 (0.0)	2 (1.9)
CNLC				0.650
1A	207 (80.9)	119 (79.3)	88 (83.0)
1B	45 (17.6)	29 (19.3)	16 (15.1)
2A	4 (1.6)	2 (1.3)	2 (1.9)
ECOG				0.222
0	247 (96.5)	147 (98.0)	100 (94.3)
1	9 (3.5)	3 (2.0)	6 (5.7)
Child-Pugh grade				0.757
A	249 (97.3)	145 (96.7)	104 (98.1)
B	7 (2.7)	5 (3.3)	2 (1.9)
Preoperative ICG retention rate	5.00 ± 2.06	3.57 ± 1.18	7.01 ± 1.14	< 0.001
Conversion therapy				1.000
No	253 (98.8)	148 (98.7)	105 (99.1)
Yes	3 (1.2)	2 (1.3)	1 (0.9)

LLR: Laparoscopic liver resection; HCC: Hepatocellular carcinoma; ICC: Intrahepatic cholangiocarcinoma; BMI: Body mass index; BCLC: Barcelona Clinic Liver Cancer; CNLC: Chinese liver cancer; ECOG: Eastern Cooperative Oncology Group; ICG: Indocyanine green.

Table 2 Intraoperative data for patients in both groups, n (%)

	Overall (n = 256)	Conventional LLR (n = 150)	Novel LLR (n = 106)	P value
Tumor size, cm	5.03 ± 2.88	4.01 ± 2.33	6.47 ± 2.96	< 0.001
Tumor location	31 (12.1)	15 (10.0)	16 (15.1)	0.218
S II	23 (9.0)	12 (8.0)	11 (10.4)
S III	39 (15.2)	27 (18.0)	12 (11.3)
S IV	46 (18.0)	32 (21.3)	14 (13.2)
S V	37 (14.5)	19 (12.7)	18 (17.0)
S VI	33 (12.9)	18 (12.0)	15 (14.2)
S VII	36 (14.1)	22 (14.7)	14 (13.2)
S VIII	2 (0.8)	2 (1.3)	0 (0.0)
S II/III	9 (3.5)	3 (2.0)	6 (5.7)
Type of resection	48 (18.8)	36 (24.0)	12 (11.3)	0.051
S5 + S6 + S7 + S8	43 (16.8)	25 (16.7)	18 (17.0)
S2 + S3 + S4	38 (14.8)	22 (14.7)	16 (15.1)
S6 + S7	35 (13.7)	23 (15.3)	12 (11.3)
S6 + S7 + S5v + S8v	38 (14.8)	16 (10.7)	22 (20.8)
S7	27 (10.5)	16 (10.7)	11 (10.4)
S7 + S8	27 (10.5)	12 (8.0)	15 (14.2)
Operative time, minute	236.34 ± 81.08	262.33 ± 83.90	199.57 ± 60.37	< 0.001
Blood loss	298.57 ± 128.82	363.34 ± 131.27	206.92 ± 37.09	< 0.001
Number of lesions				0.165
1	251 (98.0)	145 (96.7)	106 (100.0)
2	3 (1.2)	3 (2.0)	0 (0.0)
3	2 (0.8)	2 (1.3)	0 (0.0)
Distance from major vessels				0.944
> 1 cm	189 (73.8)	110 (73.3)	79 (74.5)
< 1 cm	67 (26.2)	40 (26.7)	27 (25.5)
Distance from liver capsule				0.899
< 1 cm	128 (50.0)	76 (50.7)	52 (49.1)
> 1 cm	128 (50.0)	74 (49.3)	54 (50.9)
Preoperative resection volume, mL	297.81 ± 50.90	264.38 ± 31.98	345.11 ± 31.40	< 0.001
PRLV/TLV	30.58 ± 10.06	30.37 ± 10.21	30.87 ± 9.89	0.697
Minimum surgical margin width, mm	18.95 ± 6.33	18.96 ± 6.27	18.94 ± 6.45	0.984
Total pringle maneuver time, minute	44.93 ± 10.53	45.12 ± 10.49	44.67 ± 10.64	0.737
ICG staining method				0.887
None	176 (68.8)	104 (69.3)	72 (67.9)
Negative staining	52 (20.3)	29 (19.3)	23 (21.7)
Positive staining	28 (10.9)	17 (11.3)	11 (10.4)
Blood transfusion				0.761
No	253 (98.8)	149 (99.3)	104 (98.1)
Yes	3 (1.2)	1 (0.7)	2 (1.9)
R0 resection Y	256 (100.0)	150 (100.0)	106 (100.0)	NA

LLR: Laparoscopic liver resection; PRLV/TLV: Preoperative resection volume/total liver volume; ICG: Indocyanine green; NA: Not available.

Table 3 Postoperative data for patients in both groups, n (%)

	Overall (n = 256)	Conventional LLR (n = 150)	Novel LLR (n = 106)	P value
90 days mortality
No	256 (100.0)	150 (100.0)	106 (100.0)
Postoperative hospital stays, day	5.36 ± 1.89	5.90 ± 2.17	4.59 ± 1.02	< 0.001
Readmission				1.000
No	255 (99.6)	149 (99.3)	106 (100.0)
Yes	1 (0.4)	1 (0.7)	0 (0.0)
Recurrence				0.636
No	254 (99.2)	148 (98.7)	106 (100.0)
Yes	2 (0.8)	2 (1.3)	0 (0.0)
Follow up months	10 (5, 15)	10 (5, 15)	11 (5, 16)	0.346
Liver failure				1.000
No	255 (99.6)	149 (99.3)	106 (100.0)
Yes	1 (0.4)	1 (0.7)	0 (0.0)
Ascites				0.382
No	253 (98.8)	147 (98.0)	106 (100.0)
Yes	3 (1.2)	3 (2.0)	0 (0.0)
Clavien-Dindo complication grade				0.636
< IIIa	254 (99.2)	148 (98.7)	106 (100.0)
≥ IIIa	2 (0.8)	2 (1.3)	0 (0.0)

LLR: Laparoscopic liver resection.