Radiofrequency and malignant biliary strictures: An update

Table 1 Summary of the main characteristics of the included studies (study design, population, intervention, radiofrequency ablation probe, outcomes, main findings)

Author (reference), Country, Year	Patients number	Study design	Intervention	Probe	Tumour type	Control group	Outcomes	Main findings
Steel et al[17], UK 2011	22	Prospective	ERFA before SEMS	Habib EndoHPB	CC, PC	No	Technical and clinical success; adverse events	(1) 21/22 technical success; 18/21 stent patency at 90 d; and (2) 3 AE (1 pancreatitis, 2 cholecystitis)
Figueroa- Barojas et al[18], USA 2013	20	Prospective	ERFA before stenting (metallic or plastic)	Habib EndoHPB	MBO	No	30 d patency, stricture size; adverse events	(1) Significant increase of 3.5 mm CBD diameter after RFA; and (2) 2 AE (1 pancreatitis, 1 cholecystitis)
Dolak et al[19], Austria 2014	58	Retrospective	Miscellaneous (ERFA before stenting, ERFA for blocked SEMS, percutaneous RFA)	Habib EndoHPB	MBO (mainly CC)	No	Patency, adverse events, mortality	(1) Median stent patency 170 d (95%CI 63-277): Metal vs plastic stenting (218 d vs 115 d, P = 0.051); and (2) 12 AE (1 partial liver infarction, 5 Cholangitis, 2 hemobilia, 2 cholangiosepsis, 1 hepatic coma, 1 left bundle branch block)
Sharaiha et al[20], USA 2014	66	Retrospective	ERFA before stenting (26pts) vs stenting alone (40 pts)	Habib EndoHPB	CC, PC	Yes	Survival, stricture size; Adverse events	(1) ERFA independent predictor of survival [HR 0.29 (0.11-0.76), P = 0.012]; and (2) No differences in AE (2 RFA vs 3 no-RFA)
Strand et al[21], USA 2014	48	Retrospective	ERFA (16 pts) vs PDT (32 pts)	Habib EndoHPB	CC	Yes	Survival; Adverse events	Similar survival; more stent occlusions in RFA group
Kallis et al[22], UK 2015	69	Retrospective	ERFA before stenting (23 pts) vs stenting alone (46 pts)	Habib EndoHPB	PC	Yes	Survival, morbidity, and stent patency rates	Median survival in RFA group 226 d vs 123.5 d in controls (P < 0.01); SEMS patency equivalent
Sharaiha et al[23], USA 2015	69	Retrospective (multicentric registry)	Miscellaneous (mainly ERFA before stenting)	Habib EndoHPB	MBO (mainly CC)	No	Survival; Adverse events	(1) Median survival 11.46 mo (6.2 mo-25 mo); and (2) AE 10 % (1 pancreatitis 2 cholecystitis, 1 hemobilia, 3 abdominal pain)
Laleman et al[24], Belgium 2017	18	Prospective	ERFA before stenting	ELRA	CC, PC	No	Feasibility, safety, and biliary patency rate of a new RFA device	(1) Biliary patency 80% and 69% at 90 d and 180 d respectively; and (2) 6 AE (4 cholangitis, 2 pancreatitis)
Yang et al[25], China 2018	65	RCT	ERFA before stenting (32 pts) vs stenting alone (33 pts)	Habib EndoHPB	CC	Yes	Overall survival, biliary patency; post-ERCP AE	(1) OS RFA + stent vs the stent-only (13.2 mo ± 0.6 mo vs 8.3 mo ± 0.5 mo, P < 0.001); Biliary patency RFA + stent longer than stent-only (6.8 mo vs 3.4 mo, P = 0.02); and (2) Similar AE [6.3% (2/32) vs 9.1% (3/33), P = 0.67]

ERFA: Endoscopic radiofrequency ablation; CC: Cholangiocarcinoma; PC: Pancreatic cancer; MBO: Malignant biliary obstruction; SEMS: Self-expandable metal stents; AE: Adverse events; CBD: Common bile duct; HR: Hazard ratio; PDT: Photo dynamic therapy; OS: Overall survival.