Table 1. Characteristics of the stone studies included in a systematic review and meta-analysis of the efficacy of peroral cholangioscopy for difficult bile duct stones and indeterminate strictures.

First author	Year	Setting	Study design	Type of POC	Sample size, n	Technical success rate	Patients undergoing stone removal, n	Stone clearance rate	Stones per patient, mean, n	Stone size, mean, mm	Location of > 75 % of stones	Stone removal method	Stone recurrence rate	Complication/adverse event rate	Patients lost to follow-up, n	NOS score
Akerman	2012	Single	Retrospective	Catheter-based	34	0.97	11	0.64	NR	NR	NR	EHL	NR	0	NR	4
Alameel	2013	Single	Prospective	Catheter-based	30	NR	10	0.9	NR	NR	NR	EHL	NR	0.05	0	4
Arya	2004	Multicenter	Retrospective	Mother – daughter	94	NR	94	0.9	1.92	0	Mixed	EHL	0.04	0.18	NR	4
Awadallah	2006	Single	Prospective	Mother – daughter	41	NR	9	0.78	NR	NR	Mixed	EHL	NR	0.05	1	4
Chen	2011	Multicenter	Prospective	Catheter-based	297	0.983	66	0.92	NR	NR	Extrahepatic	Laser lithotripsy	NR	0.075	20	4
Chen	2007	Multicenter	Prospective	Catheter-based	35	NR	9	1	NR	NR	NR	Multiple methods	NR	0.06	0	4
Draganov	2011	Single	Prospective	Catheter-based	75	0.933	26	0.923	3.55	16.52	NR	EHL	NR	0.048	0	4
Farnik	2014	Multicenter	Retrospective	Ultraslim endoscope	89	0.885	23	NR	NR	NR	NR	Multiple methods	NR	0.077	NR	3
Farrell	2005	Single	Prospective	Catheter-based	75	NR	26	1	NR	20	Mixed	EHL	NR	0	NR	4
Fishman	2009	Single	Retrospective	Catheter-based	128	NR	41	0.87	NR	NR	NR	EHL	NR	0	NR	4
Huang	2013	Single	Prospective	Ultraslim endoscope	22	0.82	5	1	NR	13.4	NR	POC-assisted basket	0.182	0	0	4
Itoi	2012	Single	Retrospective	Ultraslim endoscope	24	NR	8	1	NR	12	Intrahepatic	POC-assisted basket	NR	0	0	4
Itoi	2010	Single	Retrospective	Mother – daughter	108	NR	26	1	2.4	14.6	NR	Multiple methods	NR	0	NR	4
Itoi	2014	Multicenter	Prospective	Ultraslim endoscope	41	0.83	8	1	NR	NR	NR	Multiple methods	NR	0.048	NR	4
Jakobs	2007	Single	Prospective	Mother – daughter	89	NR	17	0.824	NR	22	NR	Laser lithotripsy	NR	0	NR	3
Jakobs	1996	Single	Prospective	Mother – daughter	30	NR	10	0.83	2.7	18	Mixed	Laser lithotripsy	NR	NR	NR	4
Kalaitzakis	2012	Multicenter	Retrospective	Catheter-based	165	0.95	33	0.73	NR	18	Extrahepatic	Multiple methods	NR	0.09	4	4
Kim	2011	Single	Prospective	Ultraslim endoscope	13	0.923	13	0.923	2.4	20.9	NR	Laser lithotripsy	NR	0.077	0	4
Lee TY	2012	Single	Prospective	Ultraslim endoscope	10	NR	10	0.9	2.3	19	Extrahepatic	Laser lithotripsy	NR	0.1	0	4
Lee YN	2012	Single	Prospective	Ultraslim endoscope	48	0.958	13	0.846	2.6	16.7	Extrahepatic	POC-assisted basket	NR	0	0	4
Maydeo	2011	Single	Prospective	Catheter-based	64	NR	60	1	1.5	23.4	Extrahepatic	Laser lithotripsy	NR	0.133	0	4
Meves	2014	Single	Prospective	Ultraslim endoscope	84	0.87	11	1	NR	NR	NR	Multiple methods	NR	0.12	NR	4
Moon	2009	Single	Prospective	Ultraslim endoscope	18	0.944	18	0.89	2.3	23.2	Extrahepatic	Multiple methods	NR	0	0	4
Moon	2009	Single	Prospective	Ultraslim endoscope	29	0.78	4	1	NR	NR	NR	Multiple methods	NR	0	NR	4
Mori	2012	Single	Prospective	Ultraslim endoscope	40	0.925	13	1	NR	NR	NR	Multiple methods	NR	0	NR	4
Neuhaus	1993	Single	Prospective	Mother – daughter	35	NR	12	0.83	NR	20	Extrahepatic	Laser lithotripsy	NR	0	NR	4
Patel	2014	Multicenter	Prospective	Catheter-based	69	NR	69	0.97	NR	NR	Extrahepatic	Laser lithotripsy	NR	0.041	0	4
Piraka	2007	Single	Prospective	Mother – daughter	32	NR	32	0.81	NR	12	Mixed	EHL	0.18	0.038	4	4
Pohl	2013	Single	RCT	Mixed	60	0.88	NR	NR	NR	NR	NR	Multiple methods	NR	0.117	0	3
Sauer	2013	Single	Retrospective	Mixed	20	NR	20	0.9	2.2	22	Extrahepatic	Laser lithotripsy	NR	0.25	NR	4
Sepe	2012	Single	Retrospective	Catheter-based	13	NR	13	0.769	NR	8	Cystic	EHL	0.077	0	NR	4
Tsuyuguchi	2011	Single	Prospective	Mother – daughter	122	NR	122	0.959	2.9	17	NR	Multiple methods	0.161	NR	6	3
Tsuyuguchi	2000	Single	Retrospective	Mother – daughter	25	0.92	22	0.82	NR	20	NR	Multiple methods	0.18	0.16	1	4

POC, peroral cholangioscopy; NR, not reported; EHL, electrohydraulic lithotripsy; NOS, Newcastle – Ottawa Scale.