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

Table 1 Patient demographics and tumor characteristics

Characteristics	n (%)
Patient-related factors
Sex (M/F)	882/236
Age (range) (yr)	63 (28-87)
Etiology
Hepatitis B infection	294 (26)
Hepatitis C infection	648 (58)
Hepatitis B and C infection	12 (1)
Alcohol abuse	34 (3)
Others	136 (12)
Operative situation
Primary curative hepatectomy without previous treatment	749 (67)
Primary curative hepatectomy with previous treatment	108 (10)
Primary non-curative hepatectomy	119 (11)
Second hepatectomy	123 (11)
Three or more hepatectomies	19 (2)
Baseline liver function
Serum platelet count < 105 (μL)	309 (28)
Child-Pugh grade A	985 (88)
Child-Pugh grade B/C	131/2 (12)
Liver cirrhosis1	656 (59)
Pre-operative AFP value (ng/mL)
< 20	612 (55)
≥ 20, < 100	244 (22)
≥ 100, < 400	116 (10)
≥ 400	131 (12)
Tumor-related factors
Tumor size (mm)	22 (2-250)
≤ 2	502 (45)
< 2, ≤ 5	519 (46)
> 5	97 (9)
Solitary tumor	922 (82)
Poorly differentiated	233 (21)
Microscopic vascular invasion	270 (24)
Macroscopic vascular invasion	25 (2)

¹The differentiation grade was based on the most poorly differentiated component in the entire specimen. AFP: Alpha-fetoprotein; DCP: Des-gamma-carboxyprothrombin.

Table 2 Patient demographics and tumor characteristics

	n (%)
Operative procedure
Major hepatectomy	42 (4)
Right hepatectomy	15
Left hepatectomy	20
Right trisectionectomy	2
Left trisectionectomy	2
Central bisectionectomy	3
Minor hepatectomy
Right anterior sectionectomy	26
Right posterior sectionectomy	23
Left medial sectionectomy	12
Left lateral sectionectomy	47
Bisegmentectomy	2
Segmentectomy	123 (11)
2	4
3	11
5	22
6	27
7	12
8	29
Sectionectomy or segmentectomy + limited resection	18
Limited resection	843 (75)
Multiple site	126
Single site	717
Weight of the resected specimen (g)1
< 50	542 (49)
≥ 50, < 100	243 (22)
≥ 100, < 250	195 (18)
≥ 250, < 500	87 (8)
≥ 500	35 (3)

¹Data was uncertain in 16 cases.

Table 3 Perioperative results and postoperative complications

Intraoperative results
Operative time (min)
median (range)	165 (40-685)
mean ± SD	180 ± 77
Intraoperative blood loss (mL)
median (range)	255 (5-58515)
mean ± SD	504 ± 1890
Required Pringle maneuver	200 (18%)
Required intraoperative blood transfusion	300 (26%)
Red blood cell transfusion	88 (9%)
Plasma transfusion	281 (45%)
Postoperative results
Required postoperative blood transfusion	369 (32%)
Red blood cell transfusion	111 (10%)
Plasma transfusion	356 (31%)
Complications
Class II1	120
Class III	72
Class IV	14
Class V	10
Perioperative blood transfusion	438
Surgical wound infection	58
Intra-abdominal fluid collection and/or abscess formation	37
Uncontrollable ascites	36
Bile leakage	33
Pneumonia and/or atelectasis	23
Postoperative bleeding	15
Uncontrollable pleural effusion	14

¹Perioperative blood transfusion was excluded from this category.

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.

Table 5 Summary of large-scale studies on hepatectomy for hepatitis C virus

Transection method	n	Study period	Etiology	LC	OT (median/mean)	OBL (median/mean)	MTS	BL/AFC	5-yr RFS/OS	Authors	Ref.
UD	398	1983-1997	HBV 22	52	-	-/1848	5.0 cm	-	23/34	Hanazaki	[15]
			HCV45					-
-	154	1991-1999	HBV 24	65	-	-	-	3.2/5.8	37/-	Fong et al	[16]
			HCV 6
MTC	214	1992-2001	HBV 17	47	273/284 min	1010/1628 mL	3.9 cm	13%/-	28/58	Satoi	[10]
			HCV 72
CC/UD	532	1994-2002	-	-	-	-/635 mL	-	9.0/8.4	-/-	Imamura et al	[17]
-	168	1999-2003	-	66	-	-/322 mL	5.1 cm	< 1%/< 1%	47/61	Shi et al	[18]
RFAR	55	2001-2007	HBV 24	100	-/165	-/22	-	1.8/9.0	-/-	Curro et al	[2]
			HCV 38
UD	359	2001-2010	HBV 34	-	-/291	-/1288	-	12.8/8.6	-/-	Sadamori	[19]
			HCV 45
MTC	1118	1990-2013	HBV 25	59	165/178 min	250/497 mL	2.2 cm	3.1/4.4	40/78	Present study
			HCV 60

LC: Liver cirrhosis; OT: Operative time; OBL: Operative blood loss; MTS: Median tumor size; BL: Bile leakage; AFC: Intra-abdominal abscess/fluid formation; RFS: Recurrence-free survival; OS: Overall survival; UD: Ultrasonic dissector; MTC: Microwave tissue coagulator; CC: Clamp crash; RFAR: Radiofrequency-assisted resection; HBV: Hepatitis B virus; HCV: Hepatitis C virus.