Table 1 Methodological characteristics of the included studies

Yang [6]

China

RCT

SEMS/DT

20

20

60.6

68.8

Descending 4, Sigmoid 6, Rectum 10

Descending 3, Sigmoid 5, Rectum 12

Niti-S, WallFlex

Create Medic

Xin [29]

China

RCT

SEMS/DT

50

50

71 ± 3

71 ± 5

32/18

29/21

Descending 8, Sigmoid l4, Rectum 28

Descending 7, Sigmoid l6, Rectum 27

Niti-S, WallFlex

Create Medic

Chen [30]

China

CS

SEMS/DT

27

18

60.2 ± 2.8

63.8 ± 3.5

Transverse 1, Descending 4, Sigmoid 14, Rectum 8

Descending 3, Sigmoid 8, Rectum 7

Niti-S

Create Medic

Chen [31]

China

RCT

SEMS/DT

40

40

67.00 ± 9.67

66.13 ± 11.11

22/18

24/16

Splenic flexure 6, Descending 10, Sigmoid 13, Rectum 11

Splenic flexure 7, Descending 9, Sigmoid 11, Rectum 13

A 0, B 5, C 20, D 15

A 0, B 8, C 18, D 14

Niti-S

Create Medic

Li [32]

China

CS

SEMS/DT

35

16

68.4 ± 6.9

72.2 ± 8.3

19/16

9/7

Colon 26, Rectum 9

Colon 10, Rectum 6

II 8, III 24, IV 3

II 4, III 10, IV 2

Akihisa Matsuda [33]

Japan

CS

SEMS/DT

28

45

66 ± 3.25

70 ± 5.25

17/11

29/16

Ascending 5, Transverse 3, Descending 3, Sigmoid 27, Rectum 12

Transverse 3, Descending 3, Sigmoid 27, Rectum 12

II 3, III 17, IV 8

II 4, III 22, IV 19

Niti-S, WallFlex

Dennis

Kojima [34]

Japan

CS

SEMS/DT

27

42

73 ± 17.0

65 ± 15.2

10/17

23/19

Right 4, Left 23

Right 4, Left 38

Hiroshi Takeyama [35]

Japan

CS

SEMS/DT

22

19

71.3 ± 10.3

68.5 ± 10

8/14

8/4

Transverse 7, Descending 3, Sigmoid 7, Rectum 5

Descending 3, Sigmoid 6, Rectum 3

II 6, III 11, IV 5

II 5, III 5, IV 2

Niti-S, WallFlex

Dennis

Chen [36]

China

CS

SEMS/DT

22

11

72.6 ± 4.7

68.3 ± 5.2

14/8

7/4

Left 22

Left Colon 11

Niti-S

Create Medic

Yang [37]

China

RCT

SEMS/DT

70

70

64.5 ± 9.8

66.5 ± 11.2

45/25

43/27

Hepatic flexure 17, Transverse 4, Descending 7, Sigmoid 27, Rectum 1 5

Hepatic flexure 19, Transverse 4, Descending 7, Sigmoid 27, Rectum 13

A 1, B 24, C 25, D 20

A 0, B 23, C 26, D 21

Niti-S

Create Medic

Chen [38]

China

RCT

SEMS/DT

50

50

Liu [39]

China

RCT

SEMS/DT

30

30

58.9 ± 10.3

61.2 ± 12.2

19/11

18/12

Transverse 5, Descending 6, Sigmoid 7, Rectum 12

Transverse 6, Descending 7, Sigmoid 6, Rectum 11

Satoru Kagami [40]

Japan

CS

SEMS/DT

26

33

70 ± 8.75

68 ± 11.0

17/9

23/10

Transverse 2, Descending 3, Sigmoid 17, Rectum 4

Descending 6, Sigmoid 21, Rectum 6

II 11, III 6, IV 9

II 11, III 11, IV 11

Niti-S, WallFlex

Dennis

Jun Kawachi [41]

Japan

CS

SEMS/DT

19

12

69.4 ± 12.3

74.1 ± 10.5

8/11

5/7

Splenic flexure 3, Descending 5, Sigmoid 11

Descending 1, Sigmoid 11

II 8, III 7, IV 4

II 7, III 2, IV 3

Niti-S

Create Medic

Chang [42]

China

RCT

SEMS/DT

31

32

65.7 ± 6.7

66.5 ± 6.4

18/13

20/12

Colon 20, Rectum 11

Colon 22, Rectum 11

II 7, III 15, IV 9

II 8, III 17, IV 8

Zhang [43]

China

CS

SEMS/DT

29

30

64.0 ± 16.3

66.9 ± 11.6

19/10

20/10

Splenic flexure 3, Descending 8, Sigmoid 11, Rectum 7

Splenic flexure 1, Descending 6, Sigmoid 17, Rectum 6

II 0, III 24, IV 5

II 0, III 16, IV 14

Niti-S

Create Medic

Ryuichiro Sato [44]

Japan

CS

SEMS/DT

53

23

70.8 ± 1.7

76.0 ± 2.4

28/25

12/11

Ascending 4, Transverse 11, Descending 11, Sigmoid 20, Rectum 7

Transverse 3, Descending 4, Sigmoid 11, Rectum 5

II 24, III 29

II 10, III 13

Niti-S

Dennis

Yoshiyuki Suzuki [45]

Japan

CS

SEMS/DT

19

21

67.62 ± 6.12

69.25 ± 4.0

8/11

11/10

Ascending 11, Transverse 8

Caecum 4, Ascending 6, Transverse 11

II 9, III 5, IV 5

II 8, III 12, IV 1

Yin [46]

China

RCT

SEMS/DT

35

35

56.14 ± 16.12

57.12 ± 15.02

20/15

21/14

Descending 9, Sigmoid 21, Other 5

Descending 10, Sigmoid 21, Other 4

Yue An [21]

China

CS

SEMS/DT

139

67

67.9 ± 12.5

65.9 ± 11.0

85/54

43/24

Descending 39, Sigmoid 61, Junction of Sigmoid and Rectum 16, Rectum 23

Descending 13, Sigmoid 9, Junction of Sigmoid and Rectum 31, Rectum 14

II 27, III 84, IV 28

II 12, III 35, IV 20

WallFlex

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Xu [47]

China

CS

SEMS/DT

27

32

65.2 ± 7.3

63.7 ± 12.5

17/10

19/13

Splenic flexure 2, Descending 5, Sigmoid 20

Splenic flexure 3, Descending 5, Sigmoid 24

II 5, III 16, IV 6

II 9, III 18, IV 5

Niti-S

Create Medic

Hiroyuki Inoue [48]

Japan

CS

SEMS

23

25

12/11

8/17

Right 11, Left 20, Rectum 17

WallFlex, Hanaro, Naturfit, Niti-S

Dennis

Akihiro Kondo [49]

Japan

CS

SEMS/DT

65

133

73 ± 3

72 ± 3.2

46/19

82/51

Left 58, Rectum 7

Left 99, Rectum 34

Kentaro Sato [50]

Japan

CS

SEMS/DT

60

18

69.5 ± 9.0

66.0 ± 9.25

31/29

8/10

Left 38, Rectum 22

Left 10, Rectum 8

WallFlex, Niti-S, Naturfit

Dennis

Zhang [51]

China

CS

SEMS/DT

32

30

63.2 ± 14.2

64.8 ± 10.4

20/12

18/12

Descending 11, Sigmoid 15, Rectum 6

Descending 5, Sigmoid 16, Rectum 9

B 16, C 16

B 16, C 14

Niti-S

Dennis

Okuda [52]

Japan

CS

SEMS/DT

65

115

71 ± 3.0

72 ± 2.2

28/37

49/66

Transverse 14, Descending 14, Sigmoid 37

Transverse 16, Descending 27, Sigmoid 72

II 39, III 26

II 66, III 49

WallFlex, Niti-S

Dennis, Create Medic