Effects of bariatric surgery on obesity associated gastroesophageal reflux disease: Insights from a systematic review and network meta-analysis

Abstract

BACKGROUND

Obesity is a global epidemic frequently associated with gastroesophageal reflux disease (GERD). Metabolic and bariatric surgery (MBS) is the most effective treatment for weight reduction in patients with obesity, with the most commonly performed procedures being sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one-anastomosis gastric bypass (OAGB). Many recent studies focused on determining the best procedure for patients with obesity and GERD; however, results from these studies vary, and the optimal procedure remains uncertain.

AIM

To compare the effects of MBSs – SG, RYGB, and OAGB – and their combinations with antireflux procedures on weight loss and GERD outcomes.

METHODS

A systematic search was performed to identify randomized controlled trials evaluating MBS in patients with obesity and GERD. A network meta-analysis was conducted to estimate the relative effectiveness of different procedures on body mass index reduction, percent excess weight loss, GERD remission, GERD onset, postoperative proton pump inhibitor use, esophagitis, and complication rates.

RESULTS

Sixteen randomized controlled trials including SG, RYGB, OAGB and their combined procedures (i.e., SGantiflux and OAGBantiflux), were analyzed. OAGBantiflux showed the highest body mass index reduction, and OAGB and RYGB had similar efficacies. In terms of percent excess weight loss, OAGB and RYGB ranked higher than other MBSs, whereas SGantiflux was the least effective. RYGB had the highest probability of GERD remission, followed by SG, SGantiflux, OAGB, and OAGBantiflux. SGantiflux showed the highest probability of the postoperative GERD onset, while SG was most likely to require postoperative proton pump inhibitor use and cause esophagitis. SGantiflux also demonstrated the highest complication rate, whereas OAGBantiflux was associated with the lowest, with OAGB, RYGB, and SG yielding intermediate rates in a descending order.

CONCLUSION

RYGB and OAGB were more effective than SG in patients with obesity and GERD, and addition of antireflux procedures to MBS did not improve GERD outcome.

Key Words: Gastroesophageal reflux disease; Sleeve gastrectomy; Roux-en-Y gastric bypass; One-anastomosis gastric bypass; Anti-reflux surgery; Network meta-analysis

Core Tip: For patients with obesity and gastroesophageal reflux disease (GERD), Roux-en-Y gastric bypass and one-anastomosis gastric bypass are more effective than sleeve gastrectomy for weight loss and GERD control, with Roux-en-Y gastric bypass demonstrating a 99% possibility as the most effective in GERD remission. Addition of antireflux procedures did not improve GERD outcome. It may also increase complications when sleeve gastrectomy is chosen, raising the question of whether or not an additional antireflux procedure is necessary. These findings provide more evidence to inform surgical decision-making for patients with obesity and GERD.

INTRODUCTION

With the development of metabolic and bariatric surgery (MBS), more attention is being focused on its effects on obesity-associated medical problems. Gastroesophageal reflux disease (GERD) is significantly more prevalent among patients with obesity[1]. A series of studies explored the proper procedure for patients diagnosed with obesity and GERD, but no consensus has yet been reached. Sleeve gastrectomy (SG) is one of the most commonly performed bariatric surgery techniques with a short learning curve and satisfactory outcomes; however, low GERD remission rate and GERD onset have been repeatedly reported[2], with some believing that Roux-en-Y gastric bypass (RYGB) is the most suitable procedure for patients with obesity and GERD[3]. On the contrary, one-anastomosis gastric bypass (OAGB), as a new procedure, has recently been widely performed, leading to some concerns about its effect on reflux-related diseases[4].

We further identified the effects of different procedures on obesity and GERD improvement by conducting a network meta-analysis to add evidence to future clinical decision-making for patients diagnosed with obesity and GERD.

MATERIALS AND METHODS

Registration

This network meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Incorporating Network Meta-Analyses statement[5]. The study protocol was registered with the International Prospective Register of Systematic Reviews[6] under registration number CRD420251075255.

Search strategy

The PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials databases were searched for relevant studies up to June 30, 2025. Only the randomized controlled trials (RCTs) (reported in English) that focused on the improvement of GERD in adult obesity patients after bariatric surgery were included. Supplementary Table 1 presents the search strategies for each database.

Interventions and outcomes

The included RCTs met the following criteria: Published after peer review; English language; and focused on bariatric procedures widely performed in recent years (SG, RYGB, and OAGB, as well as their combination with antireflux surgeries). The term “antireflux procedures” refers to various surgical techniques such as Nissen fundoplication, hiatal hernia repair (HHR), and other forms of antiflux procedures.

The outcomes included obesity-related criteria, such as body mass index (BMI) and percent excess weight loss (%EWL), both shown as changes after surgery, GERD-related factors [i.e., GERD remission rate, GERD onset rate, esophagitis rate, and proton pump inhibitor (PPI) usage], and surgery complications.

For BMI and %EWL, the results are presented as mean differences (MDs) representing changes after surgery. The GERD remission rate was calculated as follows: Number of patients with improved GERD compared to before surgery/number of patients with GERD before surgery. The results are presented as the risk differences (RD) reflecting the absolute change in the remission rates. The GERD onset rate refers to the rate of patients who developed GERD after the surgery among all patients without GERD before the surgery, which is expressed as a risk ratio (RR) to show the relative risk of new-onset GERD. The esophagitis rate and PPI usage are calculated as follows: (number of patients with esophagitis or taking PPI after the surgery - the number before the surgery)/total patient number, indicating outcome improvement. These within-group absolute changes are reported as RD. Surgical complications, usually reported as incidence rates, were analyzed and presented as RR comparing the surgical interventions.

Data extraction and quality of evidence

Data extraction was independently performed by two reviewers, and the following baseline characteristics were extracted: (1) First author; (2) Year of publication; (3) Country, interventions; (4) Sample size; (5) Follow-up duration; and (6) Outcomes of interest. For studies in which the outcome data were not reported in a directly usable form (e.g., reported as medians and interquartile ranges or presented only in a graphical format), we converted the data into means and standard deviations using the methods described by Wan et al[7] and Luo et al[8]. Any disagreement in data extraction was resolved by consultation with a third reviewer. The risk of bias of each RCT was assessed by two reviewers independently. The final judgement was made using the Cochrane risk of bias tool 2.0. The visualizations of the risk-of-bias assessments (traffic light and summary plots) were generated using the robvis web application developed by McGuinness and Higgins[9].

Statistical analysis

A Bayesian network meta-analysis was performed using the gemtc and rjags packages in R[10]. The Markov chain Monte Carlo method was used to estimate the relative treatment effects with 95%CI. Four Markov chains were simultaneously run with a burn-in of 20000 iterations, followed by 50000 sampling iterations. Convergence was assessed using the Brooks-Gelman-Rubin diagnostic (potential scale reduction factor < 1.05 was considered acceptable). Subsequently, network plots were created to display the geometry of the treatment comparisons. The treatment rankings were calculated using the surface under the cumulative ranking curve values[11]. The surface under the cumulative ranking curve values were plotted as a cumulative ranking line chart to visualize the probability of each treatment being the best. The league table was then constructed to present pairwise comparisons between treatments. The consistency between direct and indirect evidence was assessed using a node-splitting analysis. For outcomes with at least one closed loop in the evidence network, the inconsistency was evaluated by comparing direct and indirect estimates. P < 0.05 was indicative of a statistically significant inconsistency. Inconsistency testing was not applicable for outcomes without closed loops.

RESULTS

Characteristics of the included studies

The initial systematic search identified 1029 studies. After all exclusions through screening, 16 were retained for this network meta-analysis (Table 1)[12-27]. Among the included studies, five types of procedures (i.e., RYGB, OAGB, SG, OAGBantiflux and SGantiflux) and 2023 patients were analyzed, with a follow-up duration ranging from 12 months to 120 months. Figure 1 depicts a flow chart of the screening process.

Figure 1  Literature screening process.

Table 1 Basic information of included studies.

Ref.	Country	Comparison (n)	Follow-up	Outcome
Delko et al[12], 2024	Switzerland	RYGB (40) vs OAGB (40)	12 months	%EWL, GERD remission, GERD onset, complication
Eskandaros et al[13], 2021	Egypt	RYGB (40) vs OAGB (40)	12 months	BMI reduction, %EWL, change in PPI usage
Ospanov et al[14], 2024	Kazakhstan	OAGB (50) vs OAGB + antiflux (100)	24 months	BMI reduction, complication
Biter et al[15], 2017	United States and Netherland	RYGB (71) vs SG (74)	12 months	BMI reduction, %EWL, GERD onset, complication
Kermansaravi et al[16], 2024	Iran and Spain	OAGB (49) vs OAGB + antiflux (49)	12 months	GERD remission, GERD onset
Lee et al[17], 2025	New Zealand	RYGB (22) vs SG (21)	90 months	Change in PPI usage
Level et al[18], 2021	Venezuela	RYGB (19) vs OAGB (9)	60 months	BMI reduction, %EWL, GERD remission1
Musella et al[19], 2021	Italy	OAGB (28) vs SG (30)	12 months	BMI reduction, change in esophagitis
Olmi et al[20], 2022	Italy	SG (140) vs SG + antiflux (138)	12 months	BMI reduction, GERD onset, change in PPI usage, change in esophagitis, complication
Salman et al[21], 2023	Egypt	RYGB (31) vs OAGB (31)	6 months	BMI reduction, %EWL, GERD onset, change in PPI usage
Shivakumar et al[22], 2018	India	OAGB (101) vs SG (100)	36 months	%EWL, GERD onset, complication
Snyder et al[23], 2016	United States	SG (36) vs SG + antiflux (41)	12 months	BMI reduction, %EWL, GERD onset
Robert et al[24], 2024	France	RYGB (118) vs OAGB (114)	60 months	%EWL, GERD onset, change in PPI usage, complication
Wågen Hauge et al[25], 2025	Norway	RYGB (54) vs SG (55)	60 months	BMI reduction, change in PPI usage, change in esophagitis, complication
Salminen et al[26], 2022	Finland	RYGB (119) vs SG (121)	120 months	%EWL, GERD remission, GERD onset, change in PPI usage, complication
Kraljevic et al[27], 2025	Switzerland	RYGB (73) vs SG (69)	120 months	BMI reduction, GERD remission, GERD onset, complication

¹Although initially included, this study was later discovered with only one patient with preoperative gastroesophageal reflux disease and therefore did not contribute to the gastroesophageal reflux disease remission analysis.

BMI: Body mass index; PPI: Proton pump inhibitor; GERD: Gastroesophageal reflux disease; OAGB: One-anastomosis gastric bypass; RYGB: Roux-en-Y gastric bypass; SG: Sleeve gastrectomy; %EWL: Percent excess weight loss.

Table 1 presents detailed information on the 16 studies[12-27]. Four studies compared the effects of bariatric surgery alone with the effects of its combination with other procedures, including OAGB vs OAGB + fundoRing/nissen[14], OAGB vs OAGB + antireflux sutures[16], SG vs SG + fundoplication[20], and SG vs SG + crural repair[23]. For further analysis, these comparisons were generalized into OAGB vs OAGBantiflux or SG vs SGantiflux. All 16 studies included 2023 patients, with 587 (29%), 462 (22.8%), 646 (31.9%), 149 (7.4%), and 179 (8.8%) patients treated with RYGB, OAGB, SG, OAGBantiflux, and SGantiflux, respectively. Seven main outcomes were selected for the analysis: (1) BMI (pre-surgery - post-surgery); (2) %EWL (provided in articles); (3) GERD remission rate (rate of patients with improved GERD post-surgery); (4) GERD onset rate (rate of patients with newly developed GERD post-surgery); (5) Esophagitis (rate in all patients, post-surgery - pre-surgery); (6) PPI usage (rate in all patients, post-surgery - pre-surgery); and (7) Complications (provided in RCTs).

Risk of bias in the included studies

The quality of our analysis was assessed by two reviewers independently. Figures 2 and 3[12-27] depict the results of risk of bias analysis. All studies were identified as low bias for: (1) D1 – bias arising from the randomization process; (2) D2 – bias due to deviations from intended intervention; and (3) D4 – bias in the measurement of the outcome. However, seven studies showed some concerns. Two were identified as high bias for the bias due to missing outcome data part, which might be attributed to the long follow-up time in those studies. Five studies were also ranked as some concern in the bias in selection of the reported result part due to the lack of protocols.

Figure 2  Traffic light plot showing the risk of bias assessment of the included studies.

Figure 3  Risk of bias traffic light plot for the included studies.

Network diagrams of each outcome

Figure 4 displays the network diagrams of the direct comparison for each outcome, with lines representing the RCTs comparing those procedures, and widths indicating the number of RCTs. Most studies compared BMI, GERD onset, and complications in the patients. Only two studies evaluated SG plus antiflux and OAGB plus antiflux, potentially resulting in wide CIs and ranking uncertainty.

Figure 4 Network plot of the direct comparisons among the included interventions. A: Body mass index reduction; B: Percent excess weight loss; C: Gastroesophageal reflux disease remission; D: Gastroesophageal reflux disease onset; E: Change in proton pump inhibitor usage; F: Change in esophagitis; G: Complication. The line thickness represents the number of studies comparing the connected interventions. OAGB: One-anastomosis gastric bypass; RYGB: Roux-en-Y gastric bypass; SG: Sleeve gastrectomy.

Pairwise comparison and ranking results

BMI reduction: The pairwise and ranking results of BMI (Tables 2 and 3, Figure 5) indicated that OAGBantiflux led to the greatest BMI reduction, with an MD of 2.6 kg/m², compared to OAGB alone. Similarly, SGantiflux appeared less effective than SG alone (MD = -1.12 kg/m²). OAGB and RYGB demonstrated comparable effects on BMI reduction, both slightly greater than SG. The ranking probabilities indicated that OAGBantiflux exhibited the highest likelihood of being the most effective, whereas SGantiflux exhibited the least probability.

Figure 5 Surface under the cumulative ranking curve plot showing the probability of each intervention as the most effective. A: Body mass index reduction; B: Percent excess weight loss; C: Gastroesophageal reflux disease remission; D: Gastroesophageal reflux disease onset; E: Change in the proton pump inhibitor usage; F: Change in esophagitis; G: Complication. Higher surface under the cumulative ranking curve values indicates a higher likelihood of being the best treatment. OAGB: One-anastomosis gastric bypass; RYGB: Roux-en-Y gastric bypass; SG: Sleeve gastrectomy.

Table 2 League table showing pairwise comparisons of included interventions.

Interventions
Body mass index reduction [MD (95%CI)]
	OAGBantiflux	RYGB		SG	SGantiflux
OAGB	2.60 (0.16-5.04)	0.10 (-1.47 to 1.68)		-0.83 (-2.73 to 1.07)	-1.96 (-4.61 to 0.70)
OAGBantiflux	-	-2.50 (-5.40 to 0.40)		-3.43 (-6.52 to -0.34)	-4.56 (-8.16 to -0.95)
RYGB	-	-		-0.94 (-2.28 to 0.41)	-2.06 (-4.35 to 0.23)
SG	-	-		-	-1.12 (-2.98 to 0.73)
Percent excess weight loss [MD (95%CI)]
		RYGB	SG		SGantiflux
OAGB		-3.70 (-7.24 to -0.16)	-7.71 (-12.58 to -2.83)		-9.71 (-19.36 to -0.05)
RYGB		-	-4.01 (-8.47 to 0.45)		-6.01 (-15.46 to 3.45)
SG		-	-		-2.00 (-10.34 to 6.34)
GERD remission [RD (95%CI)]
	OAGBantiflux	RYGB		SG	SGantiflux
OAGB	-0.41 (-3.71 to 2.89)	2.95 (-1.21 to 7.10)		1.61 (-3.10 to 6.31)	0.85 (-4.79 to 6.49)
OAGBantiflux	-	3.35 (-1.95 to 8.66)		2.01 (-3.73 to 7.76)	1.26 (-5.27 to 7.79)
RYGB	-	-		-1.34 (-3.55 to 0.87)	-2.09 (-5.90 to 1.72)
SG	-	-		-	-0.75 (-3.86 to 2.35)
GERD onset [RR (95%CI)]
	OAGBantiflux	RYGB		SG	SGantiflux
OAGB	-1.43 (-2.71 to -0.15)	-1.15 (-1.94 to -0.36)		0.32 (-0.69 to 1.33)	0.42 (-1.09 to 1.92)
OAGBantiflux	-	0.28 (-1.23 to 1.78)		1.75 (0.12-3.38)	1.84 (-0.13 to 3.82)
RYGB	-	-		1.47 (0.69-2.25)	1.57 (0.21-2.92)
SG	-	-		-	0.09 (-1.02 to 1.20)
Change in proton pump inhibitor usage [RR (95%CI)]
		RYGB	SG		SGantiflux
OAGB		-0.03 (-0.22 to 0.16)	0.14 (-0.11 to 0.38)		0.01 (-0.35 to 0.38)
RYGB		-	0.16 (0.00-0.32)		0.04 (-0.27 to 0.35)
SG		-	-		-0.12 (-0.39 to 0.15)
Change in esophagitis [RR (95%CI)]
		RYGB	SG		SGantiflux
OAGB		0.40 (0.34-0.47)	0.45 (0.39-0.50)		0.23 (0.17-0.29)
RYGB		-	0.04 (0.01-0.08)		-0.17 (-0.21 to -0.13)
SG		-	-		-0.21 (-0.23 to -0.20)
Complication [RD (95%CI)]
	OAGBantiflux	RYGB		SG	SGantiflux
OAGB	-1.28 (-3.11 to 0.56)	-0.24 (-1.04 to 0.57)		-0.25 (-1.12 to 0.62)	1.15 (-0.58 to 2.88)
OAGBantiflux	-	1.04 (-0.96 to 3.04)		1.03 (-1.00 to 3.06)	2.43 (-0.10 to 4.95)
RYGB	-	-		-0.01 (-0.64 to 0.61)	1.38 (-0.24 to 3.00)
SG	-	-		-	1.40 (-0.10 to 2.89)

GERD: Gastroesophageal reflux disease; MD: Mean difference; OAGB: One-anastomosis gastric bypass; RD: Risk differences; RR: Risk ratio; RYGB: Roux-en-Y gastric bypass; SG: Sleeve gastrectomy.

Table 3 Surface under the cumulative ranking curve ranking table presenting the probabilities of each surgery being ranked for each outcome.

Outcomes	Rank	1	2	3	4	5
Body mass index reduction	OAGB	1.61%	44.33%	32.52%	13.73%	7.82%
	OAGBantiflux	88.63%	4.66%	2.68%	2.06%	1.97%
	RYGB	6.30%	40.17%	44.64%	6.86%	2.04%
	SG	1.28%	6.37%	15.23%	67.62%	9.50%
	SGantiflux	2.19%	4.47%	4.94%	9.73%	78.67%
Percent excess weight loss	OAGB	91.00%	7.45%	1.27%	0.29%	-
	RYGB	3.03%	78.64%	14.01%	4.33%	-
	SG	0.81%	5.34%	64.39%	29.47%	-
	SGantiflux	5.16%	8.58%	20.34%	65.92%	-
GERD remission	OAGB	0.00%	0.22%	0.50%	71.59%	27.69%
	OAGBantiflux	0.01%	0.14%	0.28%	27.79%	71.78%
	RYGB	99.99%	0.01%	0.00%	0.00%	0.00%
	SG	0.00%	93.61%	6.26%	0.12%	0.02%
	SGantiflux	0.00%	6.03%	92.96%	0.50%	0.51%
GERD onset	OAGB	13.99%	21.40%	64.24%	0.37%	0.00%
	OAGBantiflux	0.16%	0.43%	1.76%	38.40%	59.24%
	RYGB	0.00%	0.00%	0.14%	59.24%	40.62%
	SG	31.69%	54.52%	13.40%	0.40%	0.00%
	SGantiflux	54.16%	23.65%	20.45%	1.60%	0.14%
Change in Proton pump inhibitor usage	OAGB	13.22%	25.75%	31.91%	29.12%	-
	RYGB	1.34%	16.80%	46.09%	35.77%	-
	SG	67.47%	26.74%	5.16%	0.63%	-
	SGantiflux	17.97%	30.71%	16.85%	34.48%	-
Change in esophagitis	OAGB	2.98%	5.14%	16.60%	75.29%	-
	RYGB	34.43%	40.61%	18.14%	6.82%	-
	SG	51.39%	39.37%	8.67%	0.58%	-
	SGantiflux	11.20%	14.88%	56.60%	17.31%	-
Complication	OAGB	1.29%	69.35%	17.62%	11.30%	0.44%
	OAGBantiflux	0.26%	3.41%	3.07%	2.51%	90.75%
	RYGB	0.08%	15.07%	47.82%	33.82%	3.21%
	SG	0.01%	10.86%	31.27%	52.27%	5.59%
	SGantiflux	98.36%	1.31%	0.23%	0.09%	0.01%

GERD: Gastroesophageal reflux disease; OAGB: One-anastomosis gastric bypass; RYGB: Roux-en-Y gastric bypass; SG: Sleeve gastrectomy.

%EWL%: %EWL was compared among four procedures (Tables 2 and 3, Figure 5B). OAGB was identified as the most effective surgery, reducing an average of 9.72% more excess weight compared to SGantiflux, depicting a ranking probability of > 90%. Accordingly, RYGB exhibited the second-highest probability of being effective, followed by SG and SGantiflux.

GERD remission:Tables 2 and 3 and Figure 5C illustrate the pairwise and ranking results of GERD remission among the five procedures. RYGB exhibited a 100% probability of being the most effective GERD remission procedure. SG appeared to be more effective in GERD remission than SGantiflux. A similar pattern was observed for OAGB and OAGBantiflux.

GERD onset:Tables 2 and 3 show the results of the GERD onset. Figure 5D depicts that among all procedures, SGantiflux and SG had the highest probabilities of leading to GERD development after surgery, with the probability for SGantiflux slightly exceeding that for SG (RR = 0.09). OAGB was more likely to induce GERD compared to RYGB, whereas OAGBantiflux demonstrated a favorable effect by preventing GERD onset.

PPI usage: Seven studies, focusing on four procedures, reported postoperative PPI usage. Most studies showed that more patients were taking PPIs after surgery compared to before (Supplementary Table 2)[13,17,20,21,24-26]. Overall, SG showed the highest probability of increasing PPI usage after surgery, whereas SGantiflux, RYGB, and OAGB demonstrated comparable effects (Tables 2 and 3, Figure 5E).

Esophagitis rate: Only three studies reported changes in the esophagitis rate; therefore, heterogeneity must be considered. Two of them demonstrated higher post-surgery rates in both groups (Supplementary Table 3)[19,20,25]. Pairwise and ranking analyses indicated that SG exhibited the highest probability of causing esophagitis after the surgery, while OAGB yielded the lowest probability (Tables 2 and 3, Figure 5F).

Complications: SGantiflux demonstrated the highest probability of being associated with complications, while OAGBantiflux exhibited the least probability. For the remaining three procedures, the likelihood of complications decreased in the following order: OAGB, RYGB, and SG. However, the RD between any two of them was relatively small (Tables 2 and 3, Figure 5G).

Inconsistency

The loop-specific approach was adopted for probing inconsistency. No inconsistency was found for BMI, %EWL, GERD onset, and complications. However, for GERD remission, PPI usage, and esophagitis rate, inconsistency testing could not be performed due to a lack of closed network loops (Supplementary Table 4).

DISCUSSION

Controversy still exists with respect to the association between obesity and GERD. Patients with obesity show a higher GERD prevalence, and up to 61% of patients with obesity have concomitant GERD[28]. However, although several studies focused on this subject, the optimal surgical strategy for these patients has remained unclear. In 2024, the Society of American Gastrointestinal and Endoscopic Surgeons released the guidelines for the surgical treatment of hiatal hernias[29], with RYGB being recommended as a more suitable procedure for GERD. Nevertheless, no specific recommendation was provided for patients with obesity and GERD.

Recently, MBSs (such as SG, RYGB, and OAGB) have been widely performed, with SG and RYGB being more commonly adopted. Despite SG generally having a slightly weaker weight reduction effect compared to the other two procedures[30], all MBSs can achieve satisfactory weight control, albeit with a varied effect on GERD.

The high GERD incidence in patients with obesity might be attributed to the elevated intra-abdominal pressure caused by the adipose tissue. According to Guthrie and Jones[31], some patients can achieve GERD remission through weight reduction alone.

Regarding MBS for patients with obesity and GERD, SG, as the most commonly performed MBS, shows an unsatisfactory effect on GERD[2]. In contrast, RYGB showed a better GERD control than SG. DuPree et al[32] studied 38699 patients with obesity and GERD, showing that the remission rates of GERD after RYGB and SG were 62.8% and 15.9%, respectively. Betzler et al[33] also reported that RYGB might be more effective for patients with obesity and GERD. Delko et al[12] also concluded that RYGB is the most effective procedure for patients with morbid obesity and concomitant GERD. However, some studies have reported that RYGB has a 10.7% GERD onset rate at 5 years postoperatively[16]. Many studies have recommended RYGB as a surgical option for patients with GERD[32,34,35].

OAGB is a relatively new procedure[12], which some studies have reported as effective for weight reduction and metabolic improvement[24,36,37], even compared to RYGB[24]. However, only a limited number of studies have focused on its effects on GERD improvement, with reported postoperative GERD incidence ranging from 2% to 57%[38,39]. An RCT by Kermansaravi et al[16] suggested that the GERD onset after OAGB might be under-reported, and a combined antireflux procedure may be necessary.

Several non-RCTs recently focused on SG and SG combined with fundoplication, HHR, or other antireflux procedures, because SG, with a shorter operation time and learning curve, remains the most commonly performed procedure at present. However, these studies yielded inconsistent results. Hawasli et al[40] reported that among 40 patients with a preoperative GERD prevalence of > 95%, SG plus fundoplication achieved a complete GERD remission after surgery. However, some studies have reported unsatisfactory results. Two meta-analyses published in 2021 showed that SG plus HHR had no significant effect on the postoperative GERD improvement or onset[41,42]. These discrepancies might be attributed to some biases and technical factors, including the pylorus-to-transection starting distance along the greater curvature, the integrity of the angle of His after transection, and preservation of the gastric vagal nerves; all of which directly affect the intragastric pressure and gastric emptying.

Our network meta-analysis aimed to provide additional evidence for MBS strategies in patients with obesity and GERD. All included studies were RCTs, making the results relatively more reliable. With respect to BMI reduction and %EWL, OAGB and RYGB showed similar effects, whereas SG exhibited the least effect, which was consistent with previous studies[30]. OAGB plus antiflux showed the highest probability of BMI reduction, which warrants further clinical investigation.

We showed that RYGB had the highest probability of GERD remission, followed by SG, SG plus antiflux, OAGB, and OAGB plus antiflux. The bariatric + antiflux procedures showed lower GERD remission rates than bariatric surgery alone. Similarly, SG plus antiflux led to the highest probability of GERD onset, indicating that adding an antiflux procedure might not increase GERD remission compared to bariatric surgery alone, particularly if SG is the primary procedure.

SG showed the highest probability of leading to the development of esophagitis and the need for postoperative PPI use, indicating that it might not be the most suitable surgical procedure for patients with obesity and GERD. RYGB and OAGB showed similar effects on postoperative PPI usage and esophagitis. Finally, SG plus antiflux displayed the highest complication rate, followed by OAGB, RYGB, and SG, with OAGB plus antiflux being the safest procedure. The large difference in the complication rates between SG and OAGB with SG plus antiflux and OAGB plus antiflux warrants further clinical observation. Additionally, subgroup analysis focused on a certain BMI group, or severity of baseline GERD might provide more insights into this area.

This study had several limitations. First, although all included studies were RCTs, publication bias and there may still have been heterogeneity due to variations in their study design, surgical techniques, and criteria used to define GERD remission and onset. Additionally, follow-up duration varied among the studies, as well and studies with positive results were more likely to be published, which may also have influenced the consistency of outcomes such as long-term GERD remission. Second, the transitivity assumption of the network meta-analysis requires comparability across studies, but the baseline differences in the patient characteristics and operative details have might compromised this assumption. Third, we classified all additional procedures, such as fundoplication, fundoRing, Nissen, crural repair, and antireflux suture, under the general category of antiflux, which might have introduced bias. Fourth, the sample size and the number of studies for some comparisons were limited, potentially reducing the robustness of indirect estimates. Also, no subgroup (e.g., based on different BMI or severity of baseline GERD) analysis was conducted due to the small sample size, and larger studies are needed to provide more evidence. Fifth, the inconsistency between the direct and indirect comparisons cannot be fully excluded. Sixth, all included studies were conducted among western populations, which might limit the generalizability of our results. Lastly, a potential publication bias must be considered, as positive results are more likely to be reported. One special limitation was the lack of a unified control group. All comparisons were made between different surgical interventions in this work, which might have affected the interpretation of the absolute effect sizes. Therefore, the reported rankings and relative efficacy should be interpreted with caution.

CONCLUSION

We conducted a network meta-analysis to systematically compare the effects of different MBSs and combined procedures in patients with obesity and GERD. Our results suggested that for weight reduction, OAGB and RYGB are more effective compared to SG. With respect to GERD improvement after surgery, RYGB showed the highest probability of achieving GERD remission, while SGantiflux yielded the highest probability of GERD onset. Similarly, SG exhibited the highest probability of PPI usage and esophagitis postoperatively. SGantiflux was also observed to have the highest complication rate. However, special attentions should be paid when extrapolating the results to nonwestern populations because all studies were conducted in western countries. Although more clinical studies are needed to validate our results, our findings can provide more evidence to guide the surgical decisions for patients with obesity and GERD.