A global survey will be conducted using Questionnaire Star to collect basic information and differences in the use of reinforcement techniques among bariatric surgeons from October 30, 2023, to November 30, 2023. The survey includes 6 questions inquiring about basic information, including age, sex, work experience in bariatric surgery, time required for per SG or RYGB surgery (minutes), country, and institution. Additionally, 11 questions pertain to information on reinforcement, including whether to perform SG with staple line reinforcement, the degree of staple line reinforcement in SG, forms of staple line reinforcement in SG, whether to perform SG with omentopexy and their reasons, the degree of omentopexy in SG, whether to perform RYGB with staple line reinforcement and their reasons, the degree of staple line reinforcement in RYGB, and forms of staple line reinforcement in RYGB. The survey will be sent to surgeons through social media (eg, WeChat, Meta) and email. The email addresses of possible surgeons who have published articles in either one of the official journals of The International Federation for the Surgery of Obesity and Metabolic Disorders and the American Society for Metabolic and Bariatric Surgery, namely Obesity Surgery and Surgery for Obesity and Related Diseases, in the 3-year period from 2020 to 2022 will be captured and used. Only responses from surgeons who perform SG or RYGB will be eligible in later analysis. The survey is shown in Multimedia Appendix 1.

This systematic review and meta-analysis has been registered on PROSPERO (Prospective Register of Systematic Reviews) with the registration number CRD42022376438. The protocol is reported in accordance with the PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols) 2015 [25], which includes the search strategy, eligible criteria, study selection, data extraction and quality assessment, statistical analysis, subgroup analyses, sensitivity analyses, and publication bias.

Eligible studies have to meet all of the following inclusion criteria:

Studies will be excluded if they are animal trials or noncontrol studies or do not report sample size and outcome.

Searching work will be conducted by 2 researchers (YX and JW) in November 2023. English databases, including CENTRAL, EMBASE CINAHL, Web of Science, and PubMed, and Chinese databases, including Wanfang, China National Knowledge Infrastructure, Database of Chinese Technical Periodicals, and Chinese Biological Medicine, will be searched. The elements like titles, abstracts, and keywords in a combination of medical subject headings (MeSH) terms and free text terms will be searched to ensure an accurate and comprehensive study. The following MeSH and free text terms will be used: gastric bypass, sleeve gastrectomy, omentopexy, and reinforcement. There is no restriction on language and publication date. The detailed search strategy for PubMed is shown in Table 2.

The literature management software Endnote X9 will be used to retrieve studies and exclude duplicates. The studies’ contents and abstracts will be independently reviewed by 2 authors (YX and JW) according to the precise search strategies after they initially screened the studies that satisfy the inclusion criteria. Data extraction from the included studies, including authors, country, sample size, gender, race, time frame, other comorbidities, type of bariatric operations, reinforcement technique, and reported outcomes, will be collected and managed in Excel (Microsoft Corp; see Multimedia Appendix 2 for a sample table). The full text will then be read by 2 authors (YX and JW) to further determine suitability for inclusion. Any disputes will be settled through discussions or consultation with a third author (HZ).

Quality assessment will be performed based on the study design of the included studies. For RCTs, the Cochrane Risk of Bias tool [26] will be used, which focuses on 6 domains, including randomization, allocation concealment, application of blinding, integrity of the outcome data, selective reporting, and other biases. For CCSs, the quality of the included studies will be assessed by the Newcastle-Ottawa Scale (NOS) [27], which includes the appropriateness of the case and control, representativeness of the case, selection of the control, comparability of the case and control in the design, and statistical analysis of exposure factors. The top score of the NOS is 9, and the higher the score, the higher the quality. Quality assessment will be done by 2 researchers (YX and JW). Any disagreements will be resolved through discussion or consultation with a third researcher (HZ).

This study will use RevMan 5.4 software (Cochrane) for meta-analysis with the random effects model. We will use odds ratios as the effect measure for dichotomous variables (eg, postoperative bleeding, gastric leakage assessment, and reoperation), and mean differences for continuous variables (eg, estimated intraoperative blood loss, operative time, and length of hospital stay). All effective measures will be accompanied by their corresponding 95% CI. Heterogeneity will be evaluated using the Q test method, which calculates χ² and I² values. P<0.05 will be considered statistically significant.

The following predefined subgroups will be analyzed: study design of the included studies (RCTs or CCSs), age (≤65 years or >65 years) [28], gender (woman or man), type of bariatric surgery (SG or RYGB), materials of staple line reinforcement (eg, seamguard, fibrin sealant, absorbable polymer membrane), suture methods (eg, oversew, burying, whole layer continuing), the degree of reinforcement (partial or full), and the type of reinforcement (staple line reinforcement or omentopexy).

Sensitivity analysis will be performed to assess the robustness of the findings using the leave one out approach [17], and studies involved in this meta-analysis will be removed in turn. Sensitivity analyses on the quality and sample size of the included studies will be conducted as well, and the meta-analyses will be repeated after excluding studies whose sample sizes are <5 or those with 3 domains rated as high risk for RCTs or with a NOS score <5 for CCSs.

Publication bias in this study will be assessed using a funnel plot. A Begg test [29] and Egger test [30] will be performed using the Stata 15 software (StataCorp) to evaluate the statistical significance of the publication bias.

The web-based survey has obtained ethics approval (2023-S-25). As for systematic reviews and meta-analyses, ethics approval is not required because the data used are derived from published papers. Informed consent was not applicable.

Obesity is a disease caused by excessive accumulation of body fat due to the imbalance between energy intake and consumption [31], which is defined as a body mass index above 30 kg/m² [32]. According to the World Health Organization, more than 1.9 billion people worldwide were overweight in 2016, and more than 650 million had obesity [33]. Bariatric surgery associated with a reduction of obesity-related comorbidities has been gradually recognized globally [34,35]. However, the application of reinforcement techniques in SG or RYGB bariatric surgery remains a challenge for surgeons. In this study, we aim to investigate the opinions of bariatric surgeons on reinforcement techniques using web-based surveys and to evaluate the effectiveness of reinforcement techniques in reducing postoperative complication rates by meta-analyses and systematic review. To our knowledge, few studies have investigated the impact of different reinforcement techniques (staple line reinforcement or omentopexy) on 2 types of bariatric surgery (SG or RYGB) and included 2 study designs (RCT or CCS); these represent the strengths of our study. We will also perform subgroup analysis according to study design, age, race, type of bariatric surgery, materials of staple line reinforcement, suture methods, the degree of reinforcement, and types of reinforcement techniques. Our research will fill previous gaps and help standardize SG and RYGB procedures for bariatric surgeons and other researchers.

Our study has several limitations. First, given the broad inclusion criteria, there may be high heterogeneity among the included studies. We will minimize the potential heterogeneity by performing subgroup and sensitivity analyses. Second, due to language limitations, we will only search English and Chinese databases. We will search for references included in studies to reduce the issue of incomplete inclusion of literature due to language limitations. Third, we are aware that the email addresses obtained from the studies may include authors who are not bariatric surgeons. Therefore, we have indicated on the questionnaire that participants must be bariatric surgeons for subsequent questions to be answered.

The web-based survey is designed to reveal variations in reinforcement techniques used by bariatric surgeons in SG and RYGB procedures, while the meta-analyses and systematic review are expected to shed light on the effectiveness of these techniques in reducing the incidence of postoperative complications.