Biliary complications and efficacy after ablation of peribiliary tumors using irreversible electroporation (IRE) or radiofrequency ablation (RFA)

Figures & data

Figure 1. Flowchart of population enrollment.

Table 1. Demographic data and tumor characteristics.

Variables	IRE (%) (n = 13)	RFA (%) (n = 31)	p Value
Males (%)	10 (90.9)	16 (51.6)	.03*
Mean age (years)	69.2 ± 13.2	66.8 ± 9.2	.49
	(44–92)	(52–88)
Child-Pugh class (%)			1.00
Class A	13 (100)	29 (93.5)
Class B	0 (0)	2 (6.7)
Diagnosis (%)
HCC	11 (100)	29 (93.5)	1.00
Colorectal liver metastasis	0 (0)	2 (6.5)
Origin of disease (%)			.26
Hepatitis B virus	9 (81.8)	15 (48.4)
Hepatitis C virus	2 (18.2)	4 (12.9)
NASH cirrhosis	0 (0)	4 (12.9)
Others	0 (0)	6 (19.4)
Mean time follow up (months)	25.2 ± 15.9	22.2 ± 20.2	.31
	(10–59)	(1–80)
Tumor size, mm (range)	17.2 ± 5.2	18.4 ± 7.0	.56
	(8–25)	(10–9)
Tumor location (Couinaud segment)			.24
I	2 (15.4)	5 (16.1)
II	0 (0)	1 (3.2)
III	3 (23.1)	5 (19.4)
IV	2 (15.4)	14 (45.2)
V	5 (38.5)	4 (12.9)
VIII	1 (7.7)	1 (3.2)
Mean ± SD distance from bile duct (mm)	0.2 ± 0.9	1.5 ± 1.9	.04*
	(0–3.3)	(0–5)
Bile duct order			.06
Primary	6 (46.2)	5 (16.1)
Secondary	7 (53.8)	26 (83.9)

*p < 0.05.

Figure 2. Pre-operative, intra-operative, and post-operative imaging of IRE group. (A) Fifty-one-year-old man with a small hepatocellular carcinoma at liver segment IV. (A) The arterial phase MRI of liver showed a 25-mm arterial enhancing nodule less than 5 mm from the bile duct. (B) The axial non-contrast enhanced CT during the IRE procedure revealed the proper position of the two IRE electrodes. (C) The immediate post-operative contrast-enhanced CT showing the ablated area of the tumor. (D) A 1-month follow-up MRI revealed complete IRE ablation without residual tumor but with adjacent focal bile duct dilatation (arrow).

Figure 3. Local tumor progression-free survival in the IRE and RFA groups.

Figure 4. Biliary complication with clinically significant liver atrophy after the RFA procedure. (A) Seventy-six-year-old woman with a small hepatocellular carcinoma. (A) Contrast-enhanced CT of the liver in the portal phase showed an 11-mm washout nodule abutting the bile duct (white arrow). (B) Realtime sonography was performed to confirm the position of the RFA electrode. (C) A 1-month follow-up contrast-enhanced CT of the liver shows complete ablation with segmental bile duct dilatation (arrow). (D) A 5-month follow-up revealed lobar atrophy of the whole left lobe of liver (arrowhead) representing a major bile duct and vascular pedicle injury.

Table 2. Outcomes and complications of the procedure.

Results	IRE (%) (n = 13)	RFA (%) (n = 31)	P Value
Ablation zone size (mm)	38.2 ± 10.8	26.6 ± 6.0	<.001*
	(19–53)	(16–41)
Complete ablation	13 (100)	31 (100)	1.00
Biliary complication	2 (15.4)	13 (41.9)	.16
Clinically significant	1 (7.7)	5 (16.1)	.65
Bile duct order			.33
Primary	1 (50)	5 (38.5)
Secondary	1 (50)	8 (61.5)
Median difference pre-procedural values (min, max)
Serum bilirubin (mg/dL)	−0.14	−0.05	.44
	(−0.52 to 0.43)	(−0.7 to 2)
Alkaline phosphatase (U/L)	9.00	9.00	.93
	(−55 to 44)	(−55 to 297)
Local tumor progression	2 (15.4)	9 (29.0)	.461

*p < 0.05.

Table 3. Multivariate analysis of predictive factors for biliary complications.

	Complications		Univariate		Multivariate
Factor	No	Yes	HR (95%CI)	p Value	HR (95%CI)	p Value
Age (years)	66.7 ± 10	69.1 ± 10	1.02 (0.97,1.08)	.349	NA	NA
Ablation technique
IRE	11 (84.6)	2 (15.4)
RFA	18 (58.1)	13 (41.9)	3.94 (0.74,20.94)	.108	9.71 (1.27,76.92)	.032*
Bile duct order
Primary	6 (54.5)	5 (45.5)	1.86 (0.47,7.40)	.382	5.31 (0.72,38.99)	.101
Secondary	23 (69.7)	10 (30.3)
Tumor size (cm)	1.85 ± 0.6	1.73 ± 0.59	0.76 (0.29,2.05)	.591	NA	NA
Bile duct distance (mm)	1.34 ± 1.9 (0,5)	0.65 ± 1.4 (0,4)	0.78 (0.53,1.14)	.200	0.63 (0.40,0.996)	.048*
Ablation zone size (cm)	3.05 ± 1.0	2.70 ± 0.82	0.65 (0.32,1.30)	.220	0.83 (0.36,1.92)	.656

*p < 0.05.