Preventive drainage and anastomotic leakage after colorectal surgery

Table 1 Literature search strategy

Database	Search build	Results
PubMed	#1: “Colorectal” OR “rectal” OR “rectum” [MeSH] OR “Colon”[MeSH]; #2: “Drainage”[Mesh] OR “Drainage, Postural” OR “Manual Lymphatic Drainage” OR “Negative-Pressure Wound Therapy” OR “Paracentesis” OR “Negative Pressure Wound Therapy” OR “draining” OR “Suction” OR “drain”; #1 AND #2	3183
Web of Science	#1: ((((((((KP=(Drainage)) OR KP=(Drainage, Postural)) OR KP=(Manual Lymphatic Drainage)) OR KP=(Negative-Pressure Wound Therapy)) OR KP=(Negative Pressure Wound Therapy)) OR KP=(Paracentesis)) OR KP=(draining)) OR KP=(Suction)) ORKP=(drain) and Preprint Citation Index(Exclude -Database); #2: (((KP=(Colorectal)) OR KP=(rectal)) OR KP=(rectum)) OR KP=(Colon) and Preprint Citation Index(Exclude-Database); #1 AND #2	413

Table 2 Distribution of drainage methods among included studies

Ref.	Transanal drainage	Pelvic drain	Other drainage
Wang et al[27], 2025	Yes
Wang et al[28], 2024	Yes
Ho et al[29], 2024	Yes
Guadagni et al[24], 2024			Abdominal drain
Zhang et al[30], 2023	Yes
Sueda et al[31], 2023	Yes
Liang et al[17], 2022	Yes
Kuk et al[32], 2022	Yes
Zhao et al[11], 2021	Yes
Lee et al[33], 2021			A closed suction drain
Tamura et al[34], 2021	Yes
Challine et al[18], 2020	Yes	Yes
Carboni et al[35], 2020	Yes
Wang et al[36], 2020	Yes
Li et al[20], 2020	Yes
Kawada et al[26], 2018	Yes
Ito et al[37], 2017	Yes
Denost et al[38], 2017		Yes
Goto et al[39], 2017	Yes
Brandl et al[40], 2016	Yes
Yang et al[41], 2016	Yes
Matsuda et al[42], 2016	Yes
Hidaka et al[43], 2015	Yes
Lee et al[44], 2015	Yes
Kim et al[45], 2015	Yes
Adamova et al[21], 2014	Yes
Nishigori et al[46], 2014	Yes
Zhao et al[47], 2013	Yes
Xiao et al[48], 2011	Yes
Akiyoshi et al[55], 2011	Yes	Yes
Bülow et al[49], 2006	Yes
Peeters et al[50], 2005		Yes
Brown et al[51], 2001		Yes
Merad et al[52], 1999		Yes
Scott et al[53], 1996		Yes
Sagar et al[54], 1995		Yes