Endoscopic retrograde cholangiopancreatography drainage for palliation of malignant hilar biliary obstruction — stent-in-stent or side-by-side? A systematic review and meta-analysis

Table 1 Type of intervention and outcome of study

			Technical success		Clinical success		Rate of early adverse events		Rate of late adverse events		Stent patency		Reintervention		Procedure-related mortality
Ref.	Design	Year	SIS	SBS	SIS	SBS	SIS	SBS	SIS	SBS	SIS	SBS	SIS	SBS	SIS	SBS
Lee et al[33]	RCT	2019	34/34	32/35	32/34	29/35	4/34	4/35	6/34	8/35	Median 253 d (28-420); SD 98; mean 253	Median 262 d (9-455); SD 111.5; mean 262	15/34	12/35	0/34	0/35
Naitoh et al[30]	Cohort	2012	24/24	25/28	24/24	24/28	1/24	3/28	2/24	8/28	Median 104 d (20-600); SD 145; mean 207	Median 155 d (15–881); SD 216.5; mean 155	NA	NA	0/24	0/28
Kim et al[31]	Cohort	2012	18/22	15/19	NA	NA	5/22	6/19	11/22	7/19	NA	NA	NA	NA	NA	NA
Law et al[29]	Cohort	2013	7/7	17/17	NA	NA	NA	NA	0/7	0/17	NA	NA	3/7	9/17	0/7	0/17
Ishigaki et al[32]	Cohort	2020	40/40	23/24	37/40	23/24	9/40	11/24	4/40	3/24	Median 169 d (108-445); SD 84.25; mean 169	Median 205 d (85-NA); SD 24.39; mean 123.75	NA	NA	NA	NA

SIS: Stent-in-stent; SBS: Side-by-side; RCT: Randomized controlled trial; NA: Not available.