Endoscopic radiofrequency ablation for malignant biliary obstruction

Table 1 Technical information on endoluminal radiofrequency ablation

Ref.	RFA device	Type of RFA generator	Frequency of electric energy	Power of RFA generator	Duration of RFA	Resting Period Duration
Steel et al [24]	Habib EndoHPB	1500 RF generator, RITA medical system, Fremont, Calif, United States	400 Hz	7-10 wk	120 s	60 s
Figueroa-Barojas et al[26]	Habib EndoHPB	RITA 1500X, angioDynamics, Latham, NY, United States	Not stated	7-10 wk	120 s	60 s
Dolak et al[17]	Habib EndoHPB	Not stated	Standard high frequency generator (400-500 Hz)	7-10 wk	up to 120 s	Not stated
Sharaiha et al[27]	Habib EndoHPB	RITA 1500X, angioDynamics, Latham, NY or ERBE, United States	Not stated	7-10 wk	90-120 s	60-120 s
Strand et al[29]	Habib EndoHPB	Not stated	Not stated	7 wk for intrahepatic strictures, 10 wk for extrahepatic strictures	2 applications for 90 s	60 s
Sharaiha et al[28]	Habib EndoHPB	RITA 1500X, angioDynamics, Latham, NY or ERBE, United States	Not stated	Not stated	Not stated	Not stated
Kallis et al[35]	Habib EndoHPB	1500 RF generator, RITA medical system, Fremont, Calif or ERBE VIO200 D, ERBE medical United Kingdom, Ltd, Leeds, United Kingdom	Not stated	10 wk	120 s	Not stated
Liang et al[31]	Habib EndoHPB	RITA 1500X, angioDynamics, Latham, NY, United States	400 Hz	10 wk	120 s	60 s
Schmidt et al[30]	Habib EndoHPB	RITA 1500X, angioDynamics, Latham, NY or ERBE Vio 200, Electromedicie GmbH	400 Hz	7 wk; 7 wk	90 s; 90 s	Not stated
Laleman et al[25]	ELRA	VIVA combo generator, Taewoong Medical, Korea	Not stated	7-10 wk	120 s	Not stated
Bokemayer et al[33]	Habib EndoHPB	Not stated	Not stated	8-10 wk	Not stated	Not stated
Yang et al[32]	Habib EndoHPB	RITA 1500X, angioDynamics, Latham, NY, United States	400 Hz	7-10 wk	90 s	60 s
Inoue et al[36]	Habib EndoHPB	VIVA combo generator, Taewoong Medical, South Korea	Not stated	7 wk	90 s	Not stated

RFA: Radiofrequency ablation; ELRA: EndoLuminal Radiofrequency Ablation.

Table 2 Uncontrolled radiofrequency ablation studies

Ref.	Number of patients	Etiology	Type of study design	Case control analysis	Method	RFA device	Aim	Results
Steel et al[24]	22	CCC (n = 6) PC (n = 16)	Prospective	No	ERFA before SEMS	Habib EndoHPB	RFA catheter deployment, stent patency; adverse events (AE)	(1) 21/22 technical success; (2) 21/21 stent patency; 3/21 stent occlusion at 90 days; (3) AE 1 acute pancreatitis, 2 cholecystitis
Figueroa-Barojas et al[26]	20	CCC (n = 11) PC (n = 7) IPMN (n = 1) Gastric cancer (n = 1)	Prospective	No	ERFA before stenting (metallic or plastic)	Habib EndoHPB	Stricture diameter size; adverse events	(1) Significant increase of 3.5 mm duct diameter post RFA (P value < 0.0001); (2) 2 AE (1 mild pancreatitis, 1 cholecystitis)
Dolak et al[17]	58	MBO mainly CCC (n = 48)	Retrospective	No	ERFA + stenting, repeated ERFA for blocked SEMS, percutaneous RFA	Habib EndoHPB	Stent patency, survival adverse events, survival	(1) Median stent patency 170 d; Metal vs plastic stent (218 vs 115 d, P = 0.051); (2) Median survival 10.6 mo; (3) 12 AE (1 partial liver infarction, 5 Cholangitis, 2 hemobilia, 2 cholangiosepsis, 1 hepatic coma, 1 left bundle branch block)
Sharaiha et al[28]	69	CCC (n = 45) PC (n = 19) GB (n = 2) Gastric cancer (n = 1) Colon cancer liver metastasis (n = 3)	Retrospective (multicentric registry)	No	Mainly ERFA before placing metallic or plastic stent	Habib EndoHPB	Survival; stricture diameter; Adverse events	(1) Median survival 11.46 mo; (2) Significant improvement in stricture diameter post-ablation (P < 0.0001); (3) AE 10% (1 pancreatitis 2 cholecystitis, 1 hemobilia, 3 abdominal pain)
Laleman et al[25]	18	CCC, PC	Prospective	No	ERFA before stenting	ELRA	Feasibility, bilirubin level, survival and stent patency rate	(1) 6 AE (4 cholangitis, 2 pancreatitis); (2) Bilirubin level post-RFA decreased from 7.8 ± 1 mg/dL to 1.7 ± 0.4 mg/dL; P < 0.001; (3) Median survival of 227 d; (4) Stent patency 80% at 90 d and 69% at and 180 d respectively
Inoue et al[20]	41	MBO mainly CCC (n = 27) GB (n = 9)	Retrospective	No	ERFA before bilateral stenting (uncovered metallic)	Habib EndoHPB	Technical success; adverse effect; recurrent biliary obstruction (RBO) and stent patency rate	(1) Technical success was 95.1% (39/41); (2) 1 acute cholangitis, 1 cholecystitis, 1 nonocclusion cholangitis, 1 liver abcess; (3) RBO rate 38.5 % (15/39), and the median time to RBO was 230 d; (4) The median time to RBO was significantly longer in patients with strictures > 15 mm in length vs strictures ≤ 15 mm (314 vs 156 d; P = 0.02)

CCC: Cholangiocarcinoma; PC: Pancreatic cancer; GB: Gallbladder cancer; IPMN: Intradu ctal papillary mucinous neoplasm; RBO: Recurrent biliary obstruction.

Table 3 Controlled recurrent biliary obstruction studies

Ref.	Number of patients	Etiology	Type of study design	Case control analysis	Method	RFA device	Aim	Results
Sharaiha et al[27]	66 (26 RFA)	CCC (n = 37) PC (n = 29)	Retrospective case control study	Yes	ERFA before stenting (26pts) vs stenting alone (40 pts)	Habib EndoHPB	Survival; Stent patency; Adverse events (AE)	(1) The median survival was 5.9 mo in both groups; (2) SEMS patency rates were equivalent; (3) No differences in AE (2 RFA vs 3 no-RFA)
Strand et al[29]	48 (16 RFA)	CCC	Retrospective case control study	Yes	ERFA (16 pts) vs PDT (32)	Habib EndoHPB	Survival, stent occlusion	(1) Median survival of 9.6 mo in RFA vs 7.5 mo in PDT group; (2) RFA group more frequent stent occlusion (0.06 vs 0.02, P = 0.008) and cholangitis (0.13 vs 0.05, P = 0.008)
Kallis et al[35]	69 (23 RFA)	PC	Retrospective case control study	Yes	ERFA before stenting (23 pts) vs stenting alone (46 pts)	Habib EndoHPB	Survival, stent patency	(1) Survival time in RFA group 226 vs 123.5 da in controls (P < 0.01); (2) SEMS patency rate equivalent in both group
Liang et al[31]	76 (34 RFA)	CCC	Retrospective case control study	Yes	ERFA before stenting (34 pts) vs stenting alone (42 pts)	Habib EndoHPB	Survival, stent patency, adverse events	(1) The median survival in the ERFA + SEMS group was significantly better vs SEMS only (P = 0.036); (2) ERFA+ SEMS patency rate 9.5 mo vs 8.4 mo; (P = 0.024); (3) AE equivalent
Sampath et al[51]	25 (10 RFA)	CCC	Retrospective case control study	Yes	ERFA before stenting (10 pts) vs stenting alone (15 pts)	Habib EndoHPB	Survival	(1) Median survival 404 d vs 228 d in controls. (P < 0.001)
Schmidt et al[30]	34 (14 RFA)	CCC	Retrospective case control study	Yes	Repeated ERFA (14 pts) vs repeated PDT (20)	Habib EndoHPB	Bilirubin levem Advere events,	(1) PDT group no significant decrease (P = 0.67) vs in RFA significant decrease (P = 0.046); (2) AE more frequently in PDT (n = 8; 40%) than with RFA (n=3; 14.21%) (P = 0.277).
Bokemayer et al[33]	54 (32 RFA)	CCC (n = 45 + 1 intrahepatic); PC (n = 2); GB (n = 2); Other (n = 4)	Retrospective case control study	Yes	ERFA before stenting (32 pts) vs stenting alone (22 pts)	Habib EndoHPB	Survival	(1) Survival time in RFA group 342 ± 57 vs 221 ± 26 d in controls; (P = 0.046)
Yang et al[32]	65 (32 RFA)	CC	Randomised controlled trial	Yes	ERFA before stenting (32 pts) vs stenting alone (33 pts)	Habib EndoHPB	Overall survival, stent patency; post-ERCP AE	(1) ERFA + stent vs the stent only (13.2 ± 0.6 vs 8.3 ± 0.5 mo, P < 0.001); (2) Stent patency (6.8 vs 3.4 mo, P = 0.02); (3) Similar AE 6.3% vs 9.1%, (P = 0.67)

RFA: Recurrent biliary obstruction; CCC: Cholangiocarcinoma; PC: Pancreatic cancer; GB: Gallbladder cancer; pts: Patients; AE: Adverse events; SEMS: Self-expandable metal stents.