Comparison between uncut Roux-en-Y and Roux-en-Y reconstruction after distal gastrectomy for gastric cancer: A meta-analysis

Table 1 Jadad scoring system for randomized controlled studies

Ref.	Randomization	Double blinded	Withdrawals	Totalscore
Noh[15]	1	0	1	2
Xu et al[16]	2	0	1	3

Table 2 Newcastle-Ottawa scoring system for nonrandomized comparative studies

Ref.	Selectionstar	Comparability star	Outcomestar	Totalstar
He et al[17]	3	2	2	7
Li et al[18]	3	2	2	7
Park et al[19]	3	2	2	7
Huang et al[20]	4	2	2	8

Table 3 Characteristics of included studies in the meta-analysis (n)

Ref.	Country	Design	Group	Patients	Male/female	Mean age (yr)
Noh[15] 2000	South Korea	RCT	U-RY RY	54 51	38/16 31/20	59 53
Xu et al[16] 2010	China	RCT	U-RY RY	193 105	102/91 73/32	61.5 ± 7.5 63.2 ± 6.3
He et al[17] 2017	China	Retro	U-RY RY	80 51	50/30 24/27	58.9 ± 5.4 58.7 ± 6.3
Li et al[18] 2011	China	Retro	U-RY RY	127 46	70/57 31/15	58.1 ± 9.1 58.8 ± 11.3
Park et al[19] 2014	South Korea	Retro	U-RY RY	41 55	N/A N/A	N/A N/A
Huang et al[20] 2017	China	Retro	U-RY RY	34 54	28/6 38/16	58.7 ± 15.0 59.8 ± 10.3

N/A: Not available; RCT: Randomized controlled trials; RY: Roux-en-Y; U-RY: Uncut Roux-en-Y.

Table 4 Characteristics of included studies in the meta-analysis

Ref.	Country	Design	Group	Operation type	Pathology stage
					I	II	III
Noh[15] 2000	South Korea	RCT	U-RY RY	Open	19	22	13
					32	8	11
Xu et al[16] 2010	China	RCT	U-RY RY	Open	23	63	107
					12	34	59
He et al[17] 2017	China	Retro	U-RY RY	Open	10	31	39
					4	21	26
Li et al[18] 2011	China	Retro	U-RY RY	Open	13	37	77
					5	13	28
Park et al[19] 2014	South Korea	Retro	U-RY RY	Laparoscopic/ Laparoscopy-assisted	N/A
					N/A
Huang et al[20] 2017	China	Retro	U-RY RY	Laparoscopic/ Open	22	10	2
					28	21	5

N/A: Not available; RCT: Randomized controlled trial; Retro: Retrospective observational study; RY: Roux-en-Y; U-RY: Uncut Roux-en-Y.

Table 5 Definition of postoperative complications in the included studies

Ref.	Anastomotic	Reflux gastritis/esophagitis	Delayed gastric emptying	Roux stasis syndrome
	bleeding/stricture/ulcer
Noh[15] 2000	-/ND/ND	ND	ND	Definition D
Xu et al[16] 2010	ND/ND/-	ND	-	ND
He et al[17] 2017	-/ND/ND	Definition A	Definition B	Definition D
Li et al[18] 2011	ND/ND/-	Definition A	Definition C	Definition D
Park et al[19] 2014	-/-/-	ND	ND	ND
Huang et al[20] 2017	-/-/-	ND	ND	ND

Definition A: Gastritis/esophagitis mucosal inflammation, erosion and bleeding were confirmed by endoscopy; Definition B: Vomiting foods taken 4 to 6 h before, or gastric residue was still great than 200 mL after empty stomach more than 8 h; Definition C: Patients still need nasogastric tube for more than 10 d after surgery; Definition D: The criteria included one of the four following conditions: chronic upper abdominal pain, postprandial fullness, persistent nausea, and intermittent vomiting worsened by eating. ND: No definition.

Table 6 Meta-analysis of outcomes of interest

Outcome of interest	Studies	Patients (n)	OR/WMD	95%CI	P value
Perioperative outcomes
Operative time	4	488	-12.95	-22.29, -3.61	0.007
Intraoperative blood loss	4	488	-46.38	-91.93, -0.83	0.05
Hospital stay	4	488	-0.71	-1.69, 0.27	0.16
Postoperative complications
Anastomotic bleeding	2	471	0.41	0.07, 2.50	0.33
Anastomotic stricture	4	707	0.41	0.12, 1.42	0.16
Anastomotic ulcer	2	236	0.25	0.03, 2.49	0.24
Reflux gastritis/esophagitis	6	891	0.40	0.20, 0.80	0.009
Delayed gastric emptying	5	593	0.29	0.14, 0.61	0.001
Roux stasis syndrome	6	891	0.14	0.04, 0.50	0.002
Postoperative nutritional status
Serum hemoglobin	2	227	0.51	-0.58, 1.60	0.36
Serum total protein	2	227	0.55	-1.77, 2.86	0.64
Serum albumin	2	227	0.71	0.24, 1.19	0.003

CI: Confidence interval; OR: Odds ratio; WMD: Weighted mean differences.

Table 7 Outcomes of sensitivity analysis

Sensitivity analysis	Heterogeneity test		Overall effect
	I² (%)	Tau²	OR/WMD and 95%CI	P value
Operative time
Include all studies	84	62.60	-12.95 (-22.29 to -3.61)	0.007
Exclude "He et al 2017"	81	142.92	-20.41 (-36.14 to -4.68)	0.01
Exclude "Huang et al 2017"	88	70.94	-12.75 (-23.99 to -1.52)	0.03
Exclude "Park et al 2014"	69	18.50	-8.03 (-14.13 to -1.94)	0.01
Exclude "Li et al 2011"	88	235.46	-19.13 (-38.42 to 0.16)	0.05
Intraoperative blood loss
Include all studies	90	1798.47	-46.38 (-91.93 to -0.83)	0.05
Exclude "He et al 2017"	92	3010.33	-69.86 (-136.73 to -2.99)	0.04
Exclude "Huang et al 2017"	93	4274.27	-60.75 (-139.17 to 17.68)	0.13
Exclude "Park et al 2014"	65	259.64	-15.15 (-37.95 to 7.64)	0.19
Exclude "Li et al 2011"	93	2690.80	-64.63 (-127.90 to -1.37)	0.05
Hospital stay
Include all studies	69	0.65	-0.71 (-1.69 to 0.27)	0.16
Exclude "Huang et al 2017"	9	0.03	-1.22 (-1.71 to -0.73)	< 0.00001

CI: Confidence interval; OR: Odds ratio; WMD: Weighted mean differences.

Table 8 Subgroup analyses of studies with laparoscopic technique and different definitions

Outcome of interest	Studies	Patients (n)	OR/WMD	95%CI	P value
Laparoscopic/laparoscopy-assisted
Operative time	2	184	-31.76	-68.04, 4.51	0.09
Intraoperative blood loss	2	184	-115.14	-283.34, 53.06	0.18
Hospital stay	2	184	0.48	-0.62, 1.57	0.39
Reflux gastritis/esophagitis	2	184	0.22	0.04, 1.23	0.08
Delayed gastric emptying	2	184	0.27	0.04, 1.62	0.15
Roux stasis syndrome	2	184	0.39	0.12, 1.23	0.11
Definition A
Reflux gastritis/esophagitis	2	304	0.79	0.25, 2.49	0.68
Definition B
Delayed gastric emptying	1	131	0.62	0.12, 3.21	0.57
Definition C
Delayed gastric emptying	1	173	0.17	0.02, 1.97	0.16
Definition D
Roux stasis syndrome	3	409	0.08	0.01, 0.85	0.04

CI: Confidence interval; OR: Odds ratio; WMD: Weighted mean differences.