One-anastomosis gastric bypass vs sleeve gastrectomy for complications, perioperative status, and quality of life: Meta-analysis

Abstract

BACKGROUND

One-anastomosis gastric bypass (OAGB) and sleeve gastrectomy (SG) are safe and effective bariatric surgeries. Literature assessing the complications, mortality, operative time/minutes, hospital stay/days, gastroesophageal reflux (GORD), malnutrition, and quality of life is scarce.

AIM

To compare OAGB and SG regarding the above outcomes.

METHODS

We searched 4 databases from inception up to July 2025. The keywords bariatric surgery, metabolic surgery, gastric bypass, SG, complications, perioperative, quality of life, operative time, hospital stay, GORD, malnutrition, and mortality were used. Out of 1163 studies retrieved, 54 full texts were reviewed, and 31 studies were included in the meta-analysis.

RESULTS

No significant differences were evident between OAGB and SG regarding complications, odds ratio (OR), 1.37, 95% confidence interval (CI): 0.78-2.41. Operative time/minutes, hospital stay/days, and quality of life were similar between the two procedures, mean differences, 2.55, 95%CI: 3.61-8.70; -0.55, 95%CI: -1.12 to 0.02; and -0.37, 95%CI: -1.18 to 0.43 respectively, in sub-analyses including super-obesity and high diabetes, no significant differences were found regarding complications rate and operative time with higher hospital stay in patients with diabetes. Mortality and GORD were higher in SG, OR, 4.70, 95%CI: 1.64-13.52, and OR, 3.23, 95%CI: 1.56-6.72, while malnutrition was more common in OAGB, OR, 0.46, 95%CI: 0.36-0.59.

CONCLUSION

There were no differences between OAGB and SG regarding complications, mortality, operation time/minutes, hospital stay/days, and quality of life. Mortality and GORD were higher in SG, while malnutrition was higher in OAGB. Further well-controlled trials comparing OAGB and SG regarding long-term outcomes are needed.

Key Words: One anastomosis gastric bypass; Sleeve gastrectomy; Complications; Quality of life; Operative time; Mortality; Hospital stay

Core Tip: One-anastomosis gastric bypass and sleeve gastrectomy are the most commonly performed bariatric surgeries; both are safe and effective for weight reduction and diabetes remission. However, the choice between the two operations is to be determined. In this meta-analysis, we compared the two operations in terms of the complication rate, mortality, operative time/minutes, hospital stay/days, gastroesophageal reflux, nutritional deficiencies, and quality of life. This study gave a broad insight to inform the scientific community and help the surgeon to choose the best intervention for patients with obesity and diabetes.

INTRODUCTION

Bariatric surgery (BS) is an effective intervention for the treatment of obesity and its associated comorbidities compared to conventional treatment. BS significantly reduces healthcare costs and improves the patient’s quality of life in the long term[1]. Indication for BS is a body mass index (BMI) > 35 kg/m² in adults and in patients with a BMI < 35 kg/m² when other methods of weight loss are ineffective. However, BS is increasingly performed for obesity-related comorbidities (patients with type 2 diabetes and a BMI > 30 kg/m²[2,3]). There are three types of BS, restrictive, malabsorptive, and combined surgery, Roux-en-Y gastric bypass (RYGB) is the gold standard procedure and achieved weight loss of 30% at one year, and sleeve gastrectomy (SG) is increasingly performed worldwide and became the most commonly used BS since 2016 and showed low late major complications compared to RYGB excluding gastroesophageal reflux (GORD)[4,5]. SG induces satiety (by altering glucagon-like peptide 1 agonists and ghrelin) and calorie consumption because the majority of the stomach’s great curvature is removed to create a tubular stomach[6,7].

One-anastomosis gastric bypass (OAGB) was introduced by Dr. Rutledge in 1997 and has been increasingly performed since 2022 to become the third BS after SG and RYGB. OAGB is both a restrictive and malabsorptive procedure; it is safe, effective, and reversible, and reduces weight and obesity comorbidities, and improves quality of life[8-11]. The procedure is conducted by dividing the stomach between the antrum and body along the lesser curvature with a further division in the cephalad direction to the angle of His, then the pouch is anastomosed to the jejunal loop as an antecolic and antegastric loop gastrojejunostomy[8].

Previous meta-analyses found that OAGB is more effective in weight loss and diabetes remission compared to SG[12-17]. However, the results on complications and mortality are scarce, Barzin et al[13] found no differences in complications between the two procedures, supporting Magouliotis et al’s findings[12], except for mortality and hospital stay, which were lower in OAGB in Magouliotis et al’s study[12]. Ali et al[14] found a lower rate of hemorrhage with higher rates of GORD and leakage in OAGB; on the contrary, Wu et al[11] found a lower rate of postoperative leak, GORD, revisions, and mortality. However, the incidence of ulcers, reflux, and malnutrition was higher in OAGB. Wang et al[15] and Onzi et al[16] showed no differences in complication rates between OAGB and SG. Based on the above, a meta-analysis on complication rate, operation, and quality of life is justified for better decision-making (the best operation for a specific person) and to avoid unnecessary complications. Therefore, this meta-analysis aimed to assess the complication rate, mortality, operation time, length of hospital stay, GORD, nutritional deficiencies, and quality of life in OAGD and SG.

MATERIALS AND METHODS

Eligibility criteria according to Population, Intervention, Comparison, Outcomes and Study

This study was conducted from March to June 2025 to assess the complication rate, operative time/minutes, hospital stay/days, quality of life, GORD, nutritional deficiencies, and mortality in OAGB and SG.

Inclusion criteria

We included clinical trials, prospective, and retrospective studies from the first published article up to July 2025. The studies must compare OAGB and SG regarding the complication rate, operative time/minutes, hospital stay/days, quality of life, GORD, nutritional deficiencies, and mortality.

Exclusion criteria

Editorials, letters to the editor, case reports, case series, experts’ opinions, and cross-sectional studies were excluded.

Outcome measures

The outcome measures were: Complications rate, operative time/minutes, hospital stay/days, quality of life, GORD, nutritional deficiencies, and mortality in OAGB and SG.

Literature search and data extraction

We searched PubMed MEDLINE, Web of Science, Google Scholar, and Cochrane Library from inception up to July 2025. The keywords BS, metabolic surgery, bypass surgery, gastric bypass, SG, complications, perioperative, quality of life, operative time, GORD, malnutrition, hospital stay, and mortality were used. In addition, we screened the titles, abstracts, and references of the included studies for relevant articles. We identified 1163 studies and 767 studies after the removal of duplication; of these, 54 full texts were eligible, and 31 studies were included in the final meta-analysis (Figure 1).

Figure 1 The PRISMA chart. Studies evaluated complication rate, operative time, hospital stay, gastroesophageal reflux, malnutrition, quality of life, and mortality in one-anastomosis gastric bypass and sleeve gastrectomy.

Data extraction

The author’s name, country of publication, type of study, the study duration, number of participants in OAGB and SG groups, age, BMI, number of complications, operative time in minutes, hospital stay in days, quality of life, super-obesity, diabetes status, GORD, malnutrition, and mortality were recorded in (Tables 1, 2 and 3).

Table 1 Complications in one-anastomosis gastric bypass and sleeve gastrectomy.

Ref.	Age, OAGB vs SG, years	BMI, OAGB vs SG	Study type	Country	Study duration, years	SG, events	SG, total	OAGB, events	OAGB, total
Abouelela et al[23], 2020	44.87 ± 10.34 vs 45.11 ± 9.09	65.12 ± 5.89 vs 67.12 ± 3.95	Retrospective	Egypt	1	2	25	2	25
Bhandari et al[24], 2019	42.41 ± 11.0 vs 45.85 ± 12.2	54.23 ± 3.69 vs 56.39 ± 6.11	Retrospective	India	3	3	227	8	124
Das et al[25], 2024	47.1 vs 46.7	47.1 ± 9.75 vs 52.7 ± 7.17	Retrospective	Pakistan	2.16	4	26	4	19
Jammu and Sharma[26], 2016	38 vs 23	42.5 vs 35	Prospective	India	7	12	339	0	473
Jung et al[27], 2022	Matched	Matched	Retrospective	Canada	5	17	341	23	341
Kular et al[28], 2014	Not mentioned	Not mentioned	Retrospective	India	1.5	26	118	14	104
Lee et al. 2015[29]	35.9 ± 9.1 vs 35.9 ± 9.1	37.5 ± 6.1 vs 37.4 ± 5.9	Retrospective	Taiwan	6	8	519	10	519
Litmanovich et al[30], 2025	36.7 ± 13.5 vs 42.7 ± 15.2	52.2 ± 2.7 vs 55 ± 5.4	Retrospective	Israel	10	11	76	5	45
Madhok et al[31], 2016	51 ± 10.5 vs 45 ± 9.75	65 ± 9 vs 67 ± 6	Retrospective	United Kingdom	2	8	56	2	19
Musella et al[32], 2014	49.2 ± 9.1 vs 48.5 ± 8.7	48.1 ± 7.8 vs 48.3 ± 9.2	Retrospective	Multi-nation	1.5	20	175	3	80
Plamper et al[33], 2017	43.4 ± 11.2 vs 43.2 ± 11.1	54.6 ± 10.3 vs 54.1 ± 6.6	Retrospective	Germany	1	11	118	5	169
Plamper et al[34], 2023	42 ± 11 vs 44 ± 11	50.97 ± 7.31 vs 54.21 ± 10.07	Retrospective	Germany	5	133	241	253	911
Poljo et al[35], 2021	45.0 ± 9.1 vs 42.5 ± 10.2	42.1 ± 5.1 vs 46.7 ± 8.0	Retrospective	Austria	1.8	3	50	4	77
Rajan et al[36], 2020	42.3 ± 10.7 vs 39.2 ± 11.2	52.8 ± 1.5 vs 60.9 ± 9.3	Retrospective	Malaysia	1	1	27	0	3
Roushdy et al[37], 2020	33.8	48.6	Trial	Egypt	1	1	20	6	20
Schmitz et al[38], 2022	39.11 ± 0.9 vs 41.57 ± 1.07	64.14 ± 0.3 vs 66.91 ± 0.6	Retrospective	Germany	12	53	93	69	150
Singhal et al[39], 2022	40 vs 38	43.11 vs 41.91	Retrospective	Multi-national	1.5	233	3983	53	702
Singla et al[40], 2019	39.56 ± 9.77 vs 39.89 ± 11.75	44.32 ± 7.88 vs 44.57 ± 7.16	Retrospective	India	1	2	50	0	25
Singla et al[41], 2024	35 vs 37	61 vs 63.2	Retrospective	India	5	0	56	0	13
Soong et al[42], 2021	31.9 ± 9.7 vs 33.0 ± 10.0	56.2 ± 5.8 vs 55.9 ± 5.5	Retrospective	Taiwan	14	6	190	21	246
Tasdighi et al[43], 2022	40.4 ± 10.9 vs 39.2 ± 12.6	54.9 ± 4.6 vs 54.3 ± 3.9	Retrospective	Iran	3	15	348	32	209
Vrakopoulou et al[44], 2021	46.6 ± 7.8 vs 45.9 ± 7.5	52.7 ± 10.8 vs 52.2 ± 8.6	Retrospective	Greece	1.5	2	28	1	25
Alkhalifah et al[45], 2018	35.2 ± 10.1 vs 33.8 ± 10.4	36.4 ± 7.6 vs 40.4 ± 7.7	Prospective	Taiwan	5	Not assessed	1731	Not assessed	1107
Seetharamaiah et al[46], 2017	39.9 ± 11.75 vs 42.9 ± 14.02	39.9 ± 11.7 vs 42.9 ± 14.0	Trial	India	3	Not assessed	100	Not assessed	101
Shivakumar et al[47], 2018	39.9 ± 11.75 vs 42.9 ± 14.02	44.6 ± 7.16 vs 44.3 ± 7.88	Trial	India	3	Not assessed	100	Not assessed	101
Jain et al[48], 2021	42.9 ± 14.0 vs 39.9 ± 11.7	44.3 ± 7.88 vs 44.5 ± 7.16	Trial	India	5	Not assessed	47	Not assessed	49
Musella et al[49], 2021	18-65	48.5 ± 8.8 vs 47.5 ± 7.3	Trial	Italy	1	Not assessed	28	Not assessed	30
Vitiello et al[50], 2023	39.5 ± 10.1 vs 39.4 ± 9.9	44 ± 6 vs 44.3 ± 5.4	Retrospective	Italy	3	Not assessed	109	Not assessed	119
Abu Sneineh et al[51], 2021	Not assessed	Not assessed	Retrospective	Israel	10	Not assessed	98	Not assessed	42
Genco et al[52], 2021	Not assessed	45.2 ± 6.9 vs 46.7 ± 6.7	Prospective	Italy	10	Not assessed	48	Not assessed	59
Gambardella et al[53], 2024	40.1 ± 5.1 vs 38.9 ± 4.6	47.1 ± 2.3 vs 46.2 ± 3.6	Retrospective	Italy	5	Not assessed	57	Not assessed	128

SG: Sleeve gastrectomy; OAGB: One-anastomosis gastric bypass; BMI: Body mass index.

Table 2 Operation time, hospital stay, quality of life, and mortality in one-anastomosis gastric bypass and sleeve gastrectomy.

Ref.	Operation time, SG	Operation time, OAGB	Hospital stay, SG	Hospital stay, OAGB	Quality of life, SG	Quality of life, OAGB	Mortality, SG	Mortality, OAGB
Abouelela et al[23], 2020	69.11 ± 15.89	82.89 ± 22.89	1.87 ± 0.5	1.56 ± 0.5	Not assessed	Not assessed	Not assessed	Not assessed
Bhandari et al[24], 2019	36.12 ± 10.55	55.96 ± 25.55	Not assessed	Not assessed	Not assessed	Not assessed	1	0
Das et al[25], 2024	110.6 ± 36.5	139.7 ± 62.1	2.42 ± 1.84	2.58 ± 1.61	Not assessed	Not assessed	Not assessed	Not assessed
Jammu and Sharma[26], 2016	60 ± 7.5	57.5 ± 8.25	Not assessed	Not assessed	Not assessed	Not assessed	Not assessed	Not assessed
Kular et al[28], 2014	76.6 ± 28.3	52 ± 20.2	3.4 ± 2.4	2.5 ± 1.3	Not assessed	Not assessed	Not assessed	Not assessed
Lee et al[29], 2015	113.5 ± 31.1	117.2 ± 33.3	3.0 ± 1.7	3.4 ± 2.4	114.7 ± 14.7	109.8 ± 17.6	Not assessed	Not assessed
Madhok et al[31], 2016	75 ± 50.5	92 ± 31.5	Not assessed	Not assessed	Not assessed	Not assessed	Not assessed	Not assessed
Plamper et al[33], 2017	112.1 ± 33.5	81.7 ± 25.3	7.2 ± 5.5	4.5 ± 2.6	Not assessed	Not assessed	Not assessed	Not assessed
Plamper et al[34], 2023	94 ± 31	77 ± 19	7 ± 13	4 ± 3	Not assessed	Not assessed	Not assessed	Not assessed
Poljo et al[35], 2021	66.5 ± 25.3	99.0 ± 31.5	Not assessed	Not assessed	1.0 ± 0.4	1.0 ± 0.7	Not assessed	Not assessed
Rajan et al[36], 2020	103.5 ± 31.1	116.2 ± 32.3	3.1 ± 0.3	4.0 ± 0.0	Not assessed	Not assessed	1	0
Schmitz et al[38], 2022	92.10 ± 3.1	81.36 ± 1.6	4.53 ± 0.2	3.44 ± 0.1	Not assessed	Not assessed	Not assessed	Not assessed
Seetharamaiah et al[46], 2017	44.8 ± 10.6	64.8 ± 10.6	3.95 ± 0.73	3.2 ± 0.64	Not assessed	Not assessed	Not assessed	Not assessed
Shivakumar et al[47], 2018	44.8110.62	44.81 ± 10.62	3.95 ± 0.73	3.2 ± 0.64	Not assessed	Not assessed	Not assessed	Not assessed
Jain et al[48], 2021	Not assessed	Not assessed	Not assessed	Not assessed	1.86 ± 0.56	2.35 ± 0.41	Not assessed	Not assessed
Litmanovich et al[30], 2025	Not assessed	Not assessed	4.1 ± 1.8	3.6 ± 2.4	Not assessed	Not assessed	1	0
Singla et al[41], 2024	Not assessed	Not assessed	Not assessed	Not assessed	Not assessed	Not assessed	2	0
Tasdighi et al[43], 2022	Not assessed	Not assessed	Not assessed	Not assessed	Not assessed	Not assessed	8	0
Alkhalifah et al[45], 2018	115.2 ± 35.7	124.6 ± 38.8	3.1 ± 3.1	5.0 ± 4.1	Not assessed	Not assessed	Not assessed	Not assessed

SG: Sleeve gastrectomy; OAGB: One-anastomosis gastric bypass.

Table 3 Complications, super obesity, diabetes status, gastroesophageal reflux disease, and malnutrition in one-anastomosis gastric bypass and sleeve gastrectomy.

Ref.	Superobese, OAGB	Superobese, SG	Diabetes, OAGB, %	Diabetes, SG, %	Acute complications	Chronic complications	GORD/OAGB	GORD/SG	Malnutrition/OAGB	Malnutrition/SG
Abouelela et al[23], 2020	Yes	Yes	48	56	Yes	N. A	N. A	N. A	N. A	N. A
Bhandari et al[24], 2019	Yes	Yes	22.6	22.6	Yes	N. A	N. A	N. A	N. A	N. A
Das et al[25], 2024	No	Yes	21.1	19.2	Yes	N. A	5	9	N. A	N. A
Jammu and Sharma[26], 2016	No	No	17.4	2.7	Yes	N. A	3	32	41/473	12/339
Jung et al[27], 2022	No	No	N. A	N. A	Overall	N. A	N. A	N. A	N. A	N. A
Kular et al[28], 2014	N. A	N. A	N. A	N. A	5 vs 14	14 vs 26	2	16	6/72	2/76
Lee et al[29], 2015	No	No	N. A	N. A	Yes	N. A	N. A	N. A	N. A	N. A
Litmanovich et al[30], 2025	Yes	Yes	35.6	39.5	N. A	Yes	11	23	7/39	14/55
Madhok et al[31], 2016	Yes	Yes	31.5	30.3	0 vs 3	2 vs 5	1	5	N. A	N. A
Musella et al[32], 2014	No	No	22.9	22.9	8 vs 5	3 vs 20	N. A	N. A	11/175	4/80
Plamper et al[33], 2017	Yes	Yes	35	40.7	Yes	N. A	N. A	N. A	N. A	N. A
Plamper et al[34], 2023	Yes	Yes	78.8	55	41 vs 14	394 vs 142	76	43	182/911	29/241
Poljo et al[35], 2021	No	No	72.7	64	3 vs 1	0 vs 3	N. A	N. A	N. A	N. A
Rajan et al[36], 2020	Yes	Yes	N. A	N. A	Yes	N. A	N. A	N. A	N. A	N. A
Roushdy et al[37], 2020	No	No	N. A	N. A	Yes	N. A	N. A	N. A	N. A	N. A
Schmitz et al[38], 2022	Yes	Yes	34	45.7	N. A	69 vs 53	9	10	32/150	14/93
Singhal et al[39], 2022	No	No	33	16	Yes	N. A	N. A	N. A	N. A	N. A
Singla et al[40], 2019	No	No	85.7	77.8	N. A	Yes	N. A	N. A	N. A	N. A
Singla et al[41], 2024	Yes	Yes	N. A	N. A	N. A	Yes	N. A	N. A	N. A	N. A
Soong et al[42], 2021	Yes	Yes	N. A	N. A	Yes	N. A	N. A	N. A	17/246	5/190
Tasdighi et al[43], 2022	Yes	Yes	N. A	N. A	N. A	Yes	N. A	N. A	N. A	N. A
Vrakopoulou et al[44], 2021	Yes	Yes	100	100	Yes	N. A	N. A	N. A	N. A	N. A
Alkhalifah et al[45], 2018	No	No	30.8	18.5	Yes	N. A	0	31	43/1731	0/1107
Seetharamaiah et al[46], 2017	No	No	48	49	Yes	N. A	2	3	N. A	N. A
Shivakumar et al[47], 2018	No	No	48	49	Yes	N. A	N. A	N. A	N. A	N. A
Jain et al[48], 2021	Yes	Yes	47	49	N. A	N. A	3	4	13/101	7/100
Musella et al[49], 2021	No	No	N. A	N. A	N. A	N. A	31	28	N. A	N. A
Vitiello et al[50], 2023	No	No	N. A	N. A	N. A	N. A	25	15	N. A	N. A
Abu Sneineh et al[51], 2021	No	No	N. A	N. A	N. A	N. A	30/98	39/42	N. A	N. A
Genco et al[52], 2021	No	No	N. A	N. A	N. A	N. A	12/48	33/95	N. A	N. A
Gambardella et al[53], 2024	No	No	N. A	N. A	N. A	N. A	N. A	N. A	5/57	5/128

N. A: Not assessed; SG: Sleeve gastrectomy; OAGB: One-anastomosis gastric bypass; GORD: Gastroesophageal reflux.

Operation time and complication rate

Operation time is estimated by the total time in minutes with/without anesthesia time, and complications were identified according to Clavien-Dindo classification (I-IV) in only a few studies[18].

Quality of life assessment

The quality of life was assessed by three studies, the assessment tool varied significantly: One study used the Gastrointestinal Quality of Life Index[19] (36 items with a total score of 144), another study used the Bariatric Analysis and Reporting Outcome System and the Moorehead-Ardelt quality of life questionnaire[20], while, the third study used the satisfaction grade.

Super-obesity and high diabetes definition

Super-obesity was defined as BMI ≥ 50 kg/m², and the criteria for high diabetes is diabetes prevalence > 30% in a study population, or patients with poorly controlled diabetes.

Risk of bias assessment

Newcastle Ottawa Scale risk of bias and Cochrane Risk of Bias Assessment Tool assessed the risk of bias of the included studies[21,22] (Tables 4 and 5).

Table 4 Newcastle-Ottawa scale risk of bias assessment tool.

Ref.	Selection	Comparability	Outcome	Total score
Abouelela et al[23], 2020	3	1	2	6
Bhandari et al[24], 2019	2	1	2	5
Das et al[25], 2024	4	2	2	8
Jammu and Sharma[26], 2016	4	2	2	8
Jung et al[27], 2022	3	2	2	7
Kular et al[28], 2014	3	2	2	8
Lee et al[29], 2015	4	2	2	8
Litmanovich et al[30], 2025	3	2	2	7
Madhok et al[31], 2016	3	1	2	6
Musella et al[32], 2014	4	2	2	8
Plamper et al[33], 2017	3	1	2	6
Plamper et al[34], 2023	3	2	2	7
Poljo et al[35], 2021	2	2	2	6
Rajan et al[36], 2020	2	1	2	5
Schmitz et al[38], 2022	2	1	2	5
Singhal et al[39], 2022	3	2	2	7
Singla et al[40], 2019	2	1	2	5
Singla et al[41], 2024	3	2	2	7
Soong et al[42], 2021	3	1	2	6
Tasdighi et al[43], 2022	3	1	3	7
Vrakopoulou et al[44], 2021	3	2	2	7
Alkhalifah et al[45], 2018	3	2	2	7
Musella et al[49], 2021	4	2	2	8
Abu Sneineh et al[51], 2021	3	2	2	7
Genco et al[52], 2021	3	2	2	7
Gambardella et al[53], 2024	4	2	2	8

Table 5 Risk of bias assessment of the included studies according to the Cochrane risk of bias of randomized controlled trials.

Ref.	Selection bias1	Selection bias2	Performance bias	Attrition bias	Detection bias	Reporting bias	Overall bias
Roushdy et al[37], 2020	Low	Some concerns	Some concerns	Some concerns	Some concerns	Low	Some concerns
Seetharamaiah et al[46], 2017	Low	Some concerns	Some concerns	Some concerns	Some concerns	Low	Some concerns
Shivakumar et al[47], 2018	Low	Low	Some concerns	Some concerns	Low	Low	Low
Jain et al[48], 2021	Low	Low	High	Low	Some concern	Some concern	Some concerns
Vitiello et al[50], 2023	Low	Low	High	High	Low	Low	low

¹Random sequence generation.

²Allocation concealment.

Statistical analysis

The RevMan system (version 5.4, United Kingdom) was used for data analysis. The complication rate, GORD, malnutrition, and mortality were dichotomous, and the Odds ratio (OR) at a 95% confidence interval (CI) was applied to generate the forest plot. While the operation time/minutes, quality of life, and hospital stay/days were continuous, the standard difference was used. The random effect was used due to the substantial heterogeneity observed, except for mortality, in which no heterogeneity was found. I² was used to assess the heterogeneity among studies (I² > 50% was considered high). The χ² test and the weighted average effect size (Z) were calculated. A sub-analysis in which the studies were removed one by one was conducted to address the source of heterogeneity (Table 6). In addition, we analyzed complications according to super-obesity and diabetes status. A P value of < 0.05 was considered significant.

Table 6 The effect of different studies on heterogeneity.

Ref.	Effect on heterogeneity, complication rate	Effect on heterogeneity, operation time	Effect on heterogeneity, hospital stay
Abouelela et al[23], 2020	1% increase	No effect	No effect
Bhandari et al[24], 2019	No effect	1 decrease
Das et al[25], 2024	1% increase	No effect	No effect
Jammu and Sharma[26], 2016	1% increase	No effect
Jung et al[27], 2022	No effect
Kular et al[28], 2014	1% increase	No effect	No effect
Lee et al[29], 2015	1% increase	No effect	No effect
Litmanovich et al[30], 2025	1% increase		No effect
Madhok et al[31], 2016	1% increase	No effect
Musella et al[32], 2014	1% increase
Plamper et al[33], 2017	1% increase	No effect	No effect
Plamper et al[34], 2023	No effect	No effect	No effect
Poljo et al[35], 2021	1% increase	No effect
Rajan et al[36], 2020	1% increase	No effect	No effect
Roushdy et al[37], 2020	1% increase
Schmitz et al[38], 2022	1% increase	1% decrease	1% decrease
Singhal et al[39], 2022	2% decrease
Singla et al[40], 2019	1% increase
Singla et al[41], 2024	No effect
Soong et al[42], 2021	No effect
Tasdighi et al[43], 2022	12% decrease
Vrakopoulou et al[44], 2021	1% increase
Alkhalifah et al[45], 2018		1% decrease	3% decrease
Seetharamaiah et al[46], 2017		No effect	No effect
Shivakumar et al[47], 2018		No effect	No effect
Jain et al[48], 2021

RESULTS

Characteristics of the included studies

We included 31 studies, 23 were retrospective, 5 clinical trials, and 3 prospective studies; 16 were from Asia, 10 from Europe, 2 from Africa, 2 were multi-national, and one was from Canada. The patients’ age ranged from 23 to 51 ± 10.5 years, the BMI ranged from 36.4 ± 7.6 to 67.12 ± 3.95, and the study duration ranged from 1 to 14 years. In this meta-analysis, 22 studies with 11544 patients and 1280 events investigated the complications rate[23-44], no significant difference was found between OAGB and SG regarding total complications rate, OR, 1.37, 95%CI: 0.78-2.41, a significant heterogeneity was found, I² = 89%, χ² = 189.69, P value for heterogeneity < 0.001, Z = 1.10, and P value for overall effect, 0.27 (Figure 2).

Figure 2 Complications in one-anastomosis gastric bypass and sleeve gastrectomy. A: Forest plot; B: Funnel plot. SG: Sleeve gastrectomy; OAGB: One-anastomosis gastric bypass; CI: Confidence interval; OR: Odds ratio.

In a sub-analysis including only super-obese patients, no significant difference was found between OAGB and SG, OR, 1.49, 95%CI: 0.74-3.01; a significant heterogeneity was found, I² = 89%, χ² = 108.82, P value for heterogeneity < 0.001, Z = 1.12, and P value for overall effect, 0.26 (Figure 3A). Similarly, no significant difference was evident between OAGB and SG after including only studies with a high risk of diabetes, OR, 1.26, 95%CI: 0.62-2.57, a significant heterogeneity was found, I² = 91%, χ² = 174.10, P value for heterogeneity < 0.001, Z = 0.64, and P value for overall effect, 0.52 (Figure 3B).

Figure 3 Complications rate. A: In superobese patients; B: After eliminating studies with a high diabetes rate. SG: Sleeve gastrectomy; OAGB: One-anastomosis gastric bypass; CI: Confidence interval.

Fifteen studies with 7672 patients[23-26,28,29,31,33-36,38,45-47] were included to assess operation time/minutes, no significant difference was found between OAGB and SG, mean difference (MD), 2.55, 95%CI: 3.61-8.70, a significant heterogeneity was found, I² = 99%, χ² = 981.27, P value for heterogeneity < 0.001, Z = 0.81, and P value for overall effect, 0.42 (Figure 4). In sub-analyses including only super-obese patients and studies with a high-risk of diabetes, no significant differences were found between OAGB and SG, MD, -4.78, 95%CI: -15.55 to 6.00, and MD, -0.4, 95%CI: -6.78 to 5.98, respectively (Figure 5). The hospital stay/days was not significantly different between OAGB and SG (12 studies with 6428 patients were included)[23,25,28-30,33,34,36,38,45-47], MD: -0.55, 95%CI: -1.12 to 0.02, a significant heterogeneity was found, I² = 98%, χ² = 591.56, P value for heterogeneity < 0.001, Z = 1.91, and P value for overall effect, 0.06 (Figure 6). However, the hospital stay in super-obese patients was longer in SG compared to OAGB, MD: -1.11, 95%CI: -1.62 to -0.6, with no significant difference between the two procedures when including patients with high-risk of diabetes and MD: -0.35, 95%CI: -1.46 to 0.77 (Figure 7).

Figure 4 Operation time in one-anastomosis gastric bypass and sleeve gastrectomy. A: Forest plot; B: Funnel plot. SG: Sleeve gastrectomy; OAGB: One-anastomosis gastric bypass; CI: Confidence interval; MD: Mean difference.

Figure 5 Operation time/minutes in one-anastomosis gastric bypass and sleeve gastrectomy. A: In superobese patients; B: After eliminating studies with a high rate of diabetes. SG: Sleeve gastrectomy; OAGB: One-anastomosis gastric bypass; CI: Confidence interval.

Figure 6 Hospital stay in one-anastomosis gastric bypass and sleeve gastrectomy. A: Forest plot; B: Funnel plot. SG: Sleeve gastrectomy; OAGB: One-anastomosis gastric bypass; CI: Confidence interval; MD: Mean difference.

Figure 7 Hospital stay in one-anastomosis gastric bypass and sleeve gastrectomy. A: In super-obese patients; B: After eliminating studies with a high rate of diabetes. SG: Sleeve gastrectomy; OAGB: One-anastomosis gastric bypass; CI: Confidence interval.

The quality of life[29,35,48] and mortality[24,26,30,36,41,43,47] were not significantly different in OAGB and SG, MD: -0.37, 95%CI: 1.18-0.43. A significant heterogeneity was found, I² = 95%, χ² = 36.59, P value for heterogeneity < 0.001, Z = 0.91, and P value for overall effect, 0.36. However, higher mortality was observed in SG compared to OAGB, OR, 4.70, 95%CI: 1.64-13.52; no significant heterogeneity was found, I² = 0%, χ² = 5.14, P value for heterogeneity, 0.53, Z = 2.87, and P value for overall effect, 0.004 (Figure 8A and B).

Figure 8 Results in one-anastomosis gastric bypass and sleeve gastrectomy. A: Quality of life; B: Mortality; C: Postoperative gastroesophageal reflux; D: Malnutrition. SG: Sleeve gastrectomy; OAGB: One-anastomosis gastric bypass; CI: Confidence interval.

In this study, GORD is more common in SG compared to OAGB[25,28,30,31,34,38,45-52], with an OR of 3.23, 95%CI: 1.56-6.72. A significant heterogeneity was found, I² = 83%, χ² = 74.92, P value for heterogeneity < 0.001, Z = 3.14, and P value for overall effect, 0.002 (Figure 8C). However, malnutrition is more in OAGB compared to SG[26,28,30,32,34,38,42,45,48,53], OR, 0.46, 95%CI: 0.36-0.59, no significant heterogeneity was found, I² = 37%, χ² = 14.18, P value for heterogeneity, 0.12, Z = 6.13, and P value for overall effect < 0.001 (Figure 8D).

DISCUSSION

In this meta-analysis, no significant differences were evident between OAGB and SG regarding total complications, OR, 1.37, 95%CI: 0.78-2.41. However, mortality and GORD were higher in SG, and the OR was 4.70, 95%CI: 1.64-13.52, and 3.23, 95%CI: 1.56-6.72, respectively, while nutritional deficiencies were more common in OAGB; the OR was 0.46, 95%CI: 0.36-0.59.

The current results showed no significant differences in terms of operative time/minutes, hospital stay/days, and quality of life between the two weight loss procedures. Our findings are in line with Barzin et al[13] who found no significant differences in perioperative outcome, operative time, and hospital stay. However, we included more studies, assessed mortality, and quality of life. Importantly, Barzin et al[13] assessed the outcomes in patients with BMI > 50/kg/m². Magouliotis et al[12] observed a lower mortality and shorter mean hospital stay in OAGB, similar to the current findings. The current study included more recent studies that were published since the meta-analysis by Magouliotis et al[12]. SG is the most commonly used BS, and OAGB is gaining popularity among a significant number of surgeons[54,55]. Operation time, hospital stay, mortality, complications, and quality of life are crucial in choosing the type of BS. Therefore, comparing OAGB and SG is significant to inform the scientific community. Ali et al[14] included a small number of retrospective studies (6344 patients) and found comparable postoperative outcomes with higher GORD in SG; their findings were in line with the current findings. Our results were more reliable because we included more recent studies with a higher number of patients (17107 patients).

We found a lower mortality rate in OAGB compared to SG; our findings were similar to those of Wu et al[11], and Magouliotis et al[12] who found lower mortality in OAGB. The current findings highlighted the need for comparing OAGB and SG for specific side effects, Musella et al[49], and Si et al[56] showed higher GORD in SG and high malnutrition in OAGB, supporting Wu et al’s findings[11] showed that those who observed lower GORD than SG at the cost of malnutrition, ulcers, and bile reflux. A higher rate of GORD was reported in SG by a systematic meta-analysis including 87 studies and 27775 patients[57]. Our findings were in line with the above studies. However, our findings contradicted Esparham et al[57] who found no differences between OAGB and SG regarding new-onset reflux.

Quality of life is an important outcome of BS, Małczak et al[58] found a better quality of life in patients who underwent different BS procedures compared to non-surgical treatment. However, no meta-analysis comparing quality of life in OAGB and SG; we found no significant difference between quality of life in OAGB and SG, but our result is limited by the small number of included studies and the high heterogeneity. A more important aspect that needs consideration is the reoperation, Magouliotis et al[12], and Quan et al[59] found high reoperation in the SG group. In this study, we did not assess the reoperation.

The strength of this meta-analysis is that it is the largest up-to-date meta-analysis that assessed complications, mortality, operation time, hospital stay, GORD, nutritional deficiencies, and it is the first to assess the quality of life in OAGB and SG. In addition, we included 5 trials and 3 prospective studies[26,37,45-48,50,52]. This study was limited by pooling both retrospective and prospective studies, and the high heterogeneity observed. In addition, the pooling of different measures for the quality of life assessment introduced heterogeneity, standardized quality of life metrics are needed in future bariatric research.

CONCLUSION

There was no difference between OAGB and SG regarding complications, operation time, hospital stay in obese patients, and quality of life. Mortality, hospital stay in super-obese patients, and GORD were higher in SG, while nutritional deficiencies were higher in OAGB. Further well-controlled trials comparing OAGB and SG regarding long-term complications are highly needed.

ACKNOWLEDGEMENTS

The author gratefully acknowledges the Saudi Digital Library for free access to databases and Ihab Farah, a biostatistician in the Faculty of Science, University of Tabuk, Saudi Arabia, for the data analysis.