Four-Year Outcomes of Duodeno-Ileal Bipartition Using Self-Forming Magnets: The Sutureless Neodymium Anastomosis Procedure (SNAP) for Obesity and Type 2 Diabetes

Four-Year Outcomes of Duodeno-Ileal Bipartition Using Self-Forming Magnets: The Sutureless Neodymium Anastomosis Procedure (SNAP) for Obesity and Type 2 Diabetes | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Four-Year Outcomes of Duodeno-Ileal Bipartition Using Self-Forming Magnets: The Sutureless Neodymium Anastomosis Procedure (SNAP) for Obesity and Type 2 Diabetes Pichamol Jirapinyo, Francisco Schlottmann, David B. Lautz, Patrick Ryou, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7887832/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 11 You are reading this latest preprint version Abstract Background Single-anastomosis duodenal-ileal bypass and duodeno-ileal bipartition are effective metabolic surgeries but remain technically demanding due to the complexity and risk of duodeno-ileal anastomotic leaks.. Magnetic compression anastomosis using Self-Forming Magnets (SFM) offers a simplified, sutureless alternative that may reduce procedural risk. This study evaluated the feasibility, safety, and four-year outcomes of the SFM Sutureless Neodymium Anastomosis Procedure (SNAP) in patients with obesity and type 2 diabetes mellitus (T2DM). Methods This prospective, single-center study included patients with obesity and T2DM. The SNAP technique involved endoscopic and laparoscopic deployment of SFMs to create a duodeno-ileal anastomosis without sutures or staples. Primary endpoint was change in hemoglobin A1c (HbA1c) through 48 months. Secondary endpoints included percent total weight loss (%TWL) and safety outcomes. Results Fourteen patients (age 48 ± 9 years; 50% female; baseline BMI 40.4 ± 3.7 kg/m²) underwent successful SNAP creation (technical success 100%). Mean procedural time was 68 ± 20 minutes. No adverse events occurred. HbA1c significantly decreased from 8.3 ± 1.3% to 6.4 ± 0.6%, 6.6 ± 1.2%, 6.4 ± 1.5%, and 6.9 ± 1.8% at 12, 24, 36, and 48 months, respectively (all p < 0.05). Corresponding %TWL was 13.4 ± 8.6%, 14.2 ± 11.5%, 15.6 ± 13.6%, and 13.5 ± 12.9%. Conclusions SFM-assisted duodeno-ileal bipartition using the SNAP technique is feasible, safe, and durable, producing clinically meaningful and sustained weight loss and glycemic improvement over four years. This magnet-based, sutureless approach may represent a less invasive alternative to conventional duodeno-ileal anastomosis in metabolic surgery. Figures Figure 1 Figure 2 Figure 3 INTRODUCTION According to the most recent American Society for Metabolic and Bariatric Surgery (ASMBS)/International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO), metabolic and bariatric surgery may be considered for patients with obesity and type 2 diabetes mellitus (T2DM) 1 . New or modified surgeries continue to emerge, driven by a need to reduce adverse events, surgical complexity, and insufficient weight loss. One strategy is the reduction in the number of gastrointestinal anastomoses, such as in the single anastomosis duodenal ileal bypass with sleeve gastrectomy (SADI-S) and duodenal-ileal bi-partition. The creation of the duodenal-ileal anastomosis in these surgeries can be technically challenging with leaks and other adverse events reportedly as high as 16% 2 . Therefore, despite high weight loss and improvement in metabolic health, surgeries involving duodenal-ileal anastomoses have only seen a modest rise compared to other bariatric surgeries 3 . Recent magnet-based compression anastomosis technologies, including the Self-Forming Magnets (SFM) that our group has previously published on 4 , represents a potential solution. Magnetic compression significantly simplifies anastomosis creation while mitigating traditional concerns of bleeding and leak, since compression is a natural hemostatic clamp and the stoma is sealed centripetally over several days 5,6 . The present study reports technical feasibility, safety, efficacy and durability up to four years for patients with obesity and T2DM who underwent duodeno-ileal bipartition using the SFM Sutureless Neodymium Anastomosis Procedure (SNAP). METHODS Study Design and Patients This was a prospective, open-label, observational study performed at a single tertiary center, approved by the Institutional Review Board and the National Health Regulatory Authority. Short-term data from a subset of participants included in this study have been reported previously 7 . Inclusion criteria were age 18–65 years, BMI 30–50 kg/m 2 , and T2DM with diagnosis for more than 6 months and less than 10 years, taking at least one oral antidiabetic medication with fasting glucose < 200 mg/dL and glycosylated hemoglobin (HbA1c) 6.5–10.0% at the time of enrollment. Key exclusion criteria included type 1 diabetes, titanium or nickel allergy, insulin requirement, pregnancy, current malignant disease, presence of a pacemaker or implantable cardioverter defibrillator, and coagulopathy. Individuals who met the inclusion and exclusion criteria were screened by behavioral, nutritional, and medical evaluations. After all evaluations were completed, a consent form explaining the procedure, required follow-up, risks, and potential benefits was signed by all patients. Self-Forming Magnets (SFM) The SFM assemblies consist of a linear arrangement of 8 neodymium magnet segments encased in a nitinol exoskeleton (Fig. 1 ). Each segment is individually coated with parylene (poly-para-xylene). The SFM can be deployed using either a catheter-based endoscopic delivery system or a laparoscopic delivery system. When deployed within a gastrointestinal lumen, the SFM forms an octagonal configuration with an external diameter of 25 mm. The SFM are designed to couple with another SFM, forming an anastomosis over 5–8 days. The coupled SFM are naturally excreted, and no foreign material remains at the anastomosis. Technique The SNAP procedure entailed the coupling of an SFM delivered to the ileum and a corresponding SFM delivered to the duodenum. Following induction of general endotracheal anesthesia, the patient was positioned supine in a low lithotomy position with the lower extremities extended on stirrups with pneumatic compression stockings, and knees flexed 20–30 degrees. Both arms were abducted and secured on a board with adequate padding. The Veress needle was placed at Palmer’s point, and pneumoperitoneum was established at 12 mm Hg. Five ports were used for the procedure. The ileocecal valve (ICV) was identified, and an ileal loop 300 cm away from the ICV was grasped. A 5-mm ileotomy was created, and the SFM was delivered with a laparoscopic deployment tool under fluoroscopic guidance. The enterotomy was then closed with a single stitch of an absorbable suture (Fig. 2 ). Subsequently, an upper endoscopy was performed, delivering the second SFM in the duodenum, 2 cm from the pylorus, with an endoscopic deployment tool. The ileal loop with the first SFM was then approximated towards the duodenum, and both SFMs were coupled under laparoscopic and fluoroscopic guidance. Instruments and trocars were then removed from the abdomen under direct vision. Postoperative Care and Follow-Up Evaluations Patients were extubated after completion of the surgery. Patients were fed the morning after the procedure with clear liquids and usually discharged after 24 hours with instructions to continue with liquid/soft diet for the first 2 weeks, with no specific dietary restrictions thereafter. An abdominal X-ray was performed at 2 and 4 weeks after the procedure to determine the localization and/or expulsion of the SFM. Follow-up endoscopies were performed at 2 and 12 months after SFM placement to confirm patency of the anastomosis. Follow-up clinic visits were conducted at months 3, 6, 9, 12, 18, 24, 36, and 48 at which time weights were recorded and HgbA1c were obtained. Endpoints The primary endpoint was the change in HbA1c up to 4 years after SNAP. The secondary endpoint was the change in body weight, reported using percent total weight loss (%TWL), over the same follow-up period. Statistical Analysis Continuous variables were reported as mean ± standard deviation (SD). Categorical variables were reported as percentage (%). Postoperative changes in continuous variables compared to baseline were assessed using paired Student’s t-tests. Weight loss was reported as %TWL, calculated as (pre-procedural weight – post-procedural weight)/pre-procedural weight x 100. A p-value of ≤ 0.05 was considered statistically significant. The statistical analyses were performed using SAS OnDemand for Academics (Cary, NC). RESULTS Baseline Characteristics and Procedural Details A total of 14 subjects were enrolled. The mean baseline age was 48 ± 9 years, and 7 of the 14 subjects (50%) were female. The mean baseline BMI was 40.4 ± 3.7 kg/m 2 , and the mean HbA1c was 8.3 ± 1.3%. The average duration of T2DM was 4.8 ± 2.0 years. The technical success rate was 100% (14/14). The mean procedural time was 68 ± 20 minutes, and the mean time from enterostomy to magnet coupling was 43 ± 18 minutes. There were no adverse events. Patients were discharged home on post-operative day 1 ± 0.4. Outcomes At 12, 24, 36 and 48 months, there were significant reductions in HbA1c from the baseline value of 8.3 ± 1.3% to 6.4 ± 0.6%, 6.6 ± 1.2%, 6.4 ± 1.5% and 6.9 ± 1.8%, respectively (p < 0.05 compared to baseline for all) (Fig. 3 a). Weight also decreased significantly from 113 ± 22 kg at baseline to 98 ± 26 kg, 96 ± 27 kg, 96 ± 31 kg, and 102 ± 29 kg at 12, 24, 36 and 48 months, respectively (p < 0.01 compared to baseline for 12, 24, and 36 months; p = 0.09 at 48 months) (Fig. 3 b). These corresponded to total weight loss of 13.4 ± 8.6%, 14.2 ± 11.5%, 15.6 ± 13.6%, and 13.5 ± 12.9%, respectively (p < 0.0005 compared to baseline for all). DISCUSSION This prospective study demonstrated the safety, efficacy, and durability of the SNAP procedure in improving both T2DM and obesity for up to at least four years. Specifically, HbA1c decreased by 1.9% at one year and remained at a 1.4% reduction at four years, both of which are considered clinically significant. Patients also achieved a TWL of 13.4% at one year and maintained this weight loss at four years. The SNAP procedure represents an evolution in metabolic and bariatric surgery, combining laparoscopic and endoscopic techniques to provide a technically simpler and less invasive treatment option for patients with obesity and metabolic diseases. Anatomically, SNAP resembles the small bowel component of the single-anastomosis duodeno-ileal bypass (SADI), which is an alternative to the traditional biliopancreatic diversion with duodenal switch (BPD-DS), but without the sleeve gastrectomy component. In SADI, a single end-to-side anastomosis is created between the transected duodenum and the ileum approximately 300 cm proximal to the ileocecal valve 8 . In contrast, SNAP creates a side-to-side duodenal-ileal anastomosis using magnet coupling instead of stapling or hand-sewing, which may reduce the risks of bleeding or anastomotic leaks. Additionally, because the duodenum is not transected in SNAP, the natural enteral continuity of the distal duodenum, jejunum, and proximal ileum is preserved. As a result, nutrients can pass through both the natural route and the newly created diverted channel, unlike in SADI, where nutrient flow is directed exclusively through the new anastomosis. From a metabolic effectiveness standpoint, the SNAP procedure appears to provide benefits comparable to those of SADI. Specifically, as shown in this study, SNAP was associated with an average HbA1c reduction of 1.9% at one year and 1.4% at four years. For SADI, published studies report average HbA1c reductions of approximately 2% at one year and 1.8% at five years 8 . The metabolic benefits of SADI are thought to result from both the foregut and hindgut hypotheses 9 . The foregut hypothesis proposes that excluding nutrients from the proximal small intestine suppresses signals that promote insulin resistance and T2DM. In contrast, the hindgut hypothesis suggests that accelerating the delivery of undigested nutrients to the distal small intestine stimulates greater secretion of incretin hormones, which improve insulin sensitivity and lower blood glucose levels. For SNAP, the mechanism of metabolic benefit is likely driven primarily by the hindgut hypothesis, as nutrients can rapidly pass through the newly created duodeno-ileal anastomosis to the ileum and colon, with a marginal contribution from the foregut hypothesis due to reduced nutrient exposure in the proximal small bowel. The metabolic improvement observed following SNAP appears to be disproportionate to the amount of weight loss when compared to the SADI procedure, suggesting a possible weight-independent metabolic effect of SNAP. Specifically, while the HbA1c reduction following SNAP was similar to that reported for SADI, SNAP was associated with approximately 13–15% TWL, compared to about 30% TWL for SADI 8 . This difference is likely due to the absence of a sleeve gastrectomy component and the lack of complete exclusion of the proximal small bowel in SNAP. Nevertheless, it is noteworthy that despite the lower weight loss achieved with SNAP, the degree of metabolic improvement was comparable to that of SADI, highlighting the potential role of weight-independent mechanisms. Given the technical simplicity and its substantial metabolic effect, this suggests that SNAP could be considered for patients with metabolic disease and lower BMI, such as those with class I obesity, for whom traditional bariatric surgery is often not considered or covered by insurance due to its benefit-to-risk ratio. This study has a few limitations. First, the sample size was relatively small; however, statistically significant differences were observed in both clinical outcomes (HbA1c reduction and weight loss). Additionally, the absence of a control arm may have introduced bias and limited the ability to attribute the observed effects solely to the SNAP procedure. In conclusion, SNAP appears to be associated with sustained improvements in T2DM and obesity, with effects lasting up to at least four years. Declarations Competing Interests P.J. has received research support from Boston Scientific, Cook Medical, Fractyl, Morphic Medical, and USGI Medical, has served as a consultant to Boston Scientific, Cook Medical, ERBE, Fractyl, Morphic Medical, Olympus, Spatz Medical, and USGI Medical, is a co-founder of Bariendo, and has received royalty from Endosim. F.S. has no conflict of interest. D.L. has stock options in GI Windows. P.R. has no conflict of interest. M.R. has received research support from Boston Scientific and Olympus, has served as a consultant to Boston Scientific, Cook Medical, FujiFilm, Olympus, Medtronic, Enterasense, GI Windows, and has stock options in Enterasense and GI Windows. C.T. has served as a consultant for Boston Scientific, Endoquest Robotics, Enterasense, Enterra Medical, EnVision Endoscopy, Fractyl, Fujifilm, USGI Medical, Medtronic/Covidien, Olympus/Spiration, Softac, USGI Medical, Xenter and Morphic Medical, has served as an advisory boards member for USGI Medical and Fractyl, has received research grant and support from USGI Medical, Boston Scientific, ERBE, Fractyl, FujiFilm, Olympus/Spiration, Endoquest Robotics, GIE Medical and Morphic Medical, has served as a general partners for Blueframe Healthcare, Puma and Bioventures MedTech Funds, has served as a founder for Bariendo, Enterasense, EnVision Endoscopy and GI Windows, holds ownership interest for GI Windows, Xenter, EnVision Endoscopy, Enterasense and Softac and has received royalty from Endosim. R.B. has no conflict of interest. Author Contribution P.J. and P. R. wrote the main manuscript text and P.J. prepared figures 1-3. All authors reviewed the manuscript References De Luca M, Shikora S, Eisenberg D, et al. Scientific evidence for the updated guidelines on indications for metabolic and bariatric surgery (IFSO/ASMBS). Surg Obes Relat Dis Off J Am Soc Bariatr Surg 2024;20:991–1025. Cirera de Tudela A, Vilallonga R, Ruiz-Úcar E, et al. Management of Leak after Single Anastomosis Duodeno-Ileal Bypass with Sleeve Gastrectomy. J Laparoendosc Adv Surg Tech A 2021;31:152–160. Brown WA, de Leon Ballesteros GP, Ooi G, et al. Single Anastomosis Duodenal-Ileal Bypass with Sleeve Gastrectomy/One Anastomosis Duodenal Switch (SADI-S/OADS) IFSO Position Statement-Update 2020. Obes Surg 2021;31:3–25. Arau RT, Ortega A, Diez-Caballero A, et al. Duodeno-ileal diversion with self-forming magnets in a sutureless neodymium anastomosis procedure (SNAP) for weight recidivism after sleeve gastrectomy: feasibility and 9-month results. Surg Endosc 2024;38:5199–5206. Olavarria OA, Chhabra KR, Levi ST, et al. Small bowel magnetic compression anastomosis creation for bypass procedures in a porcine model. Surg Endosc 2025;39:2155–2163. Bhandari M, Neto MG, Brunaldi VO, et al. Immediately-Patent Magnetic Duodeno-Ileal Anastomosis (IMPA-DI): The First-in-Human Study. Obes Surg 2025;35:2053–2058. Schlottmann F, Ryou M, Lautz D, et al. Sutureless Duodeno-Ileal Anastomosis with Self-Assembling Magnets: Safety and Feasibility of a Novel Metabolic Procedure. Obes Surg 2021;31:4195–4202. Topart P, Becouarn G. The single anastomosis duodenal switch modifications: a review of the current literature on outcomes. Surg Obes Relat Dis Off J Am Soc Bariatr Surg 2017;13:1306–1312. Mingrone G, Castagneto-Gissey L. Mechanisms of early improvement/resolution of type 2 diabetes after bariatric surgery. Diabetes Metab 2009;35:518–523. Risstad H, Kristinsson JA, Fagerland MW, et al. Bile acid profiles over 5 years after gastric bypass and duodenal switch: results from a randomized clinical trial. Surg Obes Relat Dis Off J Am Soc Bariatr Surg 2017;13:1544–1553. Wang W, Cheng Z, Wang Y, et al. Role of Bile Acids in Bariatric Surgery. Front Physiol 2019;10:374. Rubino F, Forgione A, Cummings DE, et al. The mechanism of diabetes control after gastrointestinal bypass surgery reveals a role of the proximal small intestine in the pathophysiology of type 2 diabetes. Ann Surg 2006;244:741–749. Jørgensen NB, Dirksen C, Bojsen-Møller KN, et al. Exaggerated glucagon-like peptide 1 response is important for improved β-cell function and glucose tolerance after Roux-en-Y gastric bypass in patients with type 2 diabetes. Diabetes. 2013;62:3044–3052. • Additional Declarations Competing interest reported. P.J. has received research support from Boston Scientific, Cook Medical, Fractyl, Morphic Medical, and USGI Medical, has served as a consultant to Boston Scientific, Cook Medical, ERBE, Fractyl, Morphic Medical, Olympus, Spatz Medical, and USGI Medical, is a co-founder of Bariendo, and has received royalty from Endosim. F.S. has no conflict of interest. D.L. has stock options in GI Windows. P.R. has no conflict of interest. M.R. has received research support from Boston Scientific and Olympus, has served as a consultant to Boston Scientific, Cook Medical, FujiFilm, Olympus, Medtronic, Enterasense, GI Windows, and has stock options in Enterasense and GI Windows. C.T. has served as a consultant for Boston Scientific, Endoquest Robotics, Enterasense, Enterra Medical, EnVision Endoscopy, Fractyl, Fujifilm, USGI Medical, Medtronic/Covidien, Olympus/Spiration, Softac, USGI Medical, Xenter and Morphic Medical, has served as an advisory boards member for USGI Medical and Fractyl, has received research grant and support from USGI Medical, Boston Scientific, ERBE, Fractyl, FujiFilm, Olympus/Spiration, Endoquest Robotics, GIE Medical and Morphic Medical, has served as a general partners for Blueframe Healthcare, Puma and Bioventures MedTech Funds, has served as a founder for Bariendo, Enterasense, EnVision Endoscopy and GI Windows, holds ownership interest for GI Windows, Xenter, EnVision Endoscopy, Enterasense and Softac and has received royalty from Endosim. R.B. has no conflict of interest. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 22 Jan, 2026 Reviews received at journal 18 Jan, 2026 Reviews received at journal 17 Jan, 2026 Reviews received at journal 14 Jan, 2026 Reviewers agreed at journal 14 Jan, 2026 Reviewers agreed at journal 14 Jan, 2026 Reviewers agreed at journal 14 Jan, 2026 Reviewers invited by journal 13 Jan, 2026 Editor assigned by journal 21 Oct, 2025 Submission checks completed at journal 21 Oct, 2025 First submitted to journal 17 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7887832","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":576363659,"identity":"ce8200e1-ffd1-4e9f-8ef0-cfa666423b18","order_by":0,"name":"Pichamol Jirapinyo","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABEUlEQVRIiWNgGAWjYFCCgw1AQgKImY8xMDYwJEBE2YD4AEEtbGnEaoEDHjPitJgzHm778HOHRZ7B8Z5vj3l3MOTxzz5j+LmijEGO70YCVi2WDQebZ/aekSg2OHN2uzHvGYZiiXM5xpJnzjEYS+LQYnDgYDMDb5tE4oYbudukc9sYEhvOsCVINgIZG/BoYfwL1pLzDKxl/hm25J9ALfX4tDBDbMlhA2vZcIb5GMiWBAM8fmGWPSOROPPMMXNjkHUbgVosG85JGM488wB7iEkcf8z4dkddYt/x5mcPZ7bZJM47w9h8s6HMRp7vOA6HSRxgAEUHg8IBMF8CJiGBVTlYC38DRIt8A041o2AUjIJRMNIBAGtvbYZ2+86RAAAAAElFTkSuQmCC","orcid":"","institution":"Brigham and Women's Hospital","correspondingAuthor":true,"prefix":"","firstName":"Pichamol","middleName":"","lastName":"Jirapinyo","suffix":""},{"id":576363660,"identity":"3b7c122b-2c96-4aae-9ad7-77c9f00efcee","order_by":1,"name":"Francisco Schlottmann","email":"","orcid":"","institution":"University of Illinois at Chicago","correspondingAuthor":false,"prefix":"","firstName":"Francisco","middleName":"","lastName":"Schlottmann","suffix":""},{"id":576363661,"identity":"ee65855d-77d1-4853-855b-cd611e247281","order_by":2,"name":"David B. 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1","display":"","copyAsset":false,"role":"figure","size":24186,"visible":true,"origin":"","legend":"\u003cp\u003eSelf-Forming Magnets (SFMs).\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7887832/v1/294f9bf11b83d19bdd777dbb.jpg"},{"id":100662016,"identity":"12616bd2-6eca-4a6e-ba9a-1779e16aeb92","added_by":"auto","created_at":"2026-01-20 08:53:53","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":82379,"visible":true,"origin":"","legend":"\u003cp\u003eSutureless Neodymium Anastomosis Procedure (SNAP) showing coupling of Self-Forming Magnets (SFM) delivered to the ileum and the corresponding SFM delivered to the duodenum.\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7887832/v1/113a529f291488511ef6e0f0.jpg"},{"id":100662044,"identity":"c7c5bd11-677d-4bc8-9b3c-370e454715cd","added_by":"auto","created_at":"2026-01-20 08:54:36","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":316592,"visible":true,"origin":"","legend":"\u003cp\u003eMetabolic improvement and weight loss at 1, 2, 3 and 4 years following the SNAP procedure. \u003cstrong\u003eA\u003c/strong\u003e) Improvement in hemoglobin A1c. \u003cstrong\u003eB\u003c/strong\u003e) Improvement in weight.\u003c/p\u003e","description":"","filename":"Figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7887832/v1/f760c2e4734220c9d155e2c1.jpg"},{"id":100665587,"identity":"5517f82a-b100-41df-a96c-8f1a3a79caa9","added_by":"auto","created_at":"2026-01-20 09:28:30","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":876820,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7887832/v1/0807ebf1-ce5a-439c-b6be-945176784b57.pdf"}],"financialInterests":"Competing interest reported. P.J. has received research support from Boston Scientific, Cook Medical, Fractyl, Morphic Medical, and USGI Medical, has served as a consultant to Boston Scientific, Cook Medical, ERBE, Fractyl, Morphic Medical, Olympus, Spatz Medical, and USGI Medical, is a co-founder of Bariendo, and has received royalty from Endosim. \n\nF.S. has no conflict of interest. \n\nD.L. has stock options in GI Windows. \n\nP.R. has no conflict of interest. \n\nM.R. has received research support from Boston Scientific and Olympus, has served as a consultant to Boston Scientific, Cook Medical, FujiFilm, Olympus, Medtronic, Enterasense, GI Windows, and has stock options in Enterasense and GI Windows. \n\nC.T. has served as a consultant for Boston Scientific, Endoquest Robotics, Enterasense, Enterra Medical, EnVision Endoscopy, Fractyl, Fujifilm, USGI Medical, Medtronic/Covidien, Olympus/Spiration, Softac, USGI Medical, Xenter and Morphic Medical, has served as an advisory boards member for USGI Medical and Fractyl, has received research grant and support from USGI Medical, Boston Scientific, ERBE, Fractyl, FujiFilm, Olympus/Spiration, Endoquest Robotics, GIE Medical and Morphic Medical, has served as a general partners for Blueframe Healthcare, Puma and Bioventures MedTech Funds, has served as a founder for Bariendo, Enterasense, EnVision Endoscopy and GI Windows, holds ownership interest for GI Windows, Xenter, EnVision Endoscopy, Enterasense and Softac and has received royalty from Endosim. \n\nR.B. has no conflict of interest.","formattedTitle":"Four-Year Outcomes of Duodeno-Ileal Bipartition Using Self-Forming Magnets: The Sutureless Neodymium Anastomosis Procedure (SNAP) for Obesity and Type 2 Diabetes","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eAccording to the most recent American Society for Metabolic and Bariatric Surgery (ASMBS)/International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO), metabolic and bariatric surgery may be considered for patients with obesity and type 2 diabetes mellitus (T2DM)\u003csup\u003e1\u003c/sup\u003e. New or modified surgeries continue to emerge, driven by a need to reduce adverse events, surgical complexity, and insufficient weight loss. One strategy is the reduction in the number of gastrointestinal anastomoses, such as in the single anastomosis duodenal ileal bypass with sleeve gastrectomy (SADI-S) and duodenal-ileal bi-partition.\u003c/p\u003e \u003cp\u003eThe creation of the duodenal-ileal anastomosis in these surgeries can be technically challenging with leaks and other adverse events reportedly as high as 16%\u003csup\u003e2\u003c/sup\u003e. Therefore, despite high weight loss and improvement in metabolic health, surgeries involving duodenal-ileal anastomoses have only seen a modest rise compared to other bariatric surgeries\u003csup\u003e3\u003c/sup\u003e. Recent magnet-based compression anastomosis technologies, including the Self-Forming Magnets (SFM) that our group has previously published on\u003csup\u003e4\u003c/sup\u003e, represents a potential solution. Magnetic compression significantly simplifies anastomosis creation while mitigating traditional concerns of bleeding and leak, since compression is a natural hemostatic clamp and the stoma is sealed centripetally over several days\u003csup\u003e5,6\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe present study reports technical feasibility, safety, efficacy and durability up to four years for patients with obesity and T2DM who underwent duodeno-ileal bipartition using the SFM Sutureless Neodymium Anastomosis Procedure (SNAP).\u003c/p\u003e"},{"header":"METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Design and Patients\u003c/h2\u003e \u003cp\u003e This was a prospective, open-label, observational study performed at a single tertiary center, approved by the Institutional Review Board and the National Health Regulatory Authority. Short-term data from a subset of participants included in this study have been reported previously\u003csup\u003e7\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eInclusion criteria were age 18\u0026ndash;65 years, BMI 30\u0026ndash;50 kg/m\u003csup\u003e2\u003c/sup\u003e, and T2DM with diagnosis for more than 6 months and less than 10 years, taking at least one oral antidiabetic medication with fasting glucose\u0026thinsp;\u0026lt;\u0026thinsp;200 mg/dL and glycosylated hemoglobin (HbA1c) 6.5\u0026ndash;10.0% at the time of enrollment. Key exclusion criteria included type 1 diabetes, titanium or nickel allergy, insulin requirement, pregnancy, current malignant disease, presence of a pacemaker or implantable cardioverter defibrillator, and coagulopathy.\u003c/p\u003e \u003cp\u003eIndividuals who met the inclusion and exclusion criteria were screened by behavioral, nutritional, and medical evaluations. After all evaluations were completed, a consent form explaining the procedure, required follow-up, risks, and potential benefits was signed by all patients.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSelf-Forming Magnets (SFM)\u003c/h3\u003e\n\u003cp\u003eThe SFM assemblies consist of a linear arrangement of 8 neodymium magnet segments encased in a nitinol exoskeleton (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Each segment is individually coated with parylene (poly-para-xylene). The SFM can be deployed using either a catheter-based endoscopic delivery system or a laparoscopic delivery system. When deployed within a gastrointestinal lumen, the SFM forms an octagonal configuration with an external diameter of 25 mm. The SFM are designed to couple with another SFM, forming an anastomosis over 5\u0026ndash;8 days. The coupled SFM are naturally excreted, and no foreign material remains at the anastomosis.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\n\u003ch3\u003eTechnique\u003c/h3\u003e\n\u003cp\u003eThe SNAP procedure entailed the coupling of an SFM delivered to the ileum and a corresponding SFM delivered to the duodenum. Following induction of general endotracheal anesthesia, the patient was positioned supine in a low lithotomy position with the lower extremities extended on stirrups with pneumatic compression stockings, and knees flexed 20\u0026ndash;30 degrees. Both arms were abducted and secured on a board with adequate padding. The Veress needle was placed at Palmer\u0026rsquo;s point, and pneumoperitoneum was established at 12 mm Hg. Five ports were used for the procedure. The ileocecal valve (ICV) was identified, and an ileal loop 300 cm away from the ICV was grasped. A 5-mm ileotomy was created, and the SFM was delivered with a laparoscopic deployment tool under fluoroscopic guidance. The enterotomy was then closed with a single stitch of an absorbable suture (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eSubsequently, an upper endoscopy was performed, delivering the second SFM in the duodenum, 2 cm from the pylorus, with an endoscopic deployment tool. The ileal loop with the first SFM was then approximated towards the duodenum, and both SFMs were coupled under laparoscopic and fluoroscopic guidance. Instruments and trocars were then removed from the abdomen under direct vision.\u003c/p\u003e\n\u003ch3\u003ePostoperative Care and Follow-Up Evaluations\u003c/h3\u003e\n\u003cp\u003ePatients were extubated after completion of the surgery. Patients were fed the morning after the procedure with clear liquids and usually discharged after 24 hours with instructions to continue with liquid/soft diet for the first 2 weeks, with no specific dietary restrictions thereafter. An abdominal X-ray was performed at 2 and 4 weeks after the procedure to determine the localization and/or expulsion of the SFM. Follow-up endoscopies were performed at 2 and 12 months after SFM placement to confirm patency of the anastomosis. Follow-up clinic visits were conducted at months 3, 6, 9, 12, 18, 24, 36, and 48 at which time weights were recorded and HgbA1c were obtained.\u003c/p\u003e\n\u003ch3\u003eEndpoints\u003c/h3\u003e\n\u003cp\u003eThe primary endpoint was the change in HbA1c up to 4 years after SNAP. The secondary endpoint was the change in body weight, reported using percent total weight loss (%TWL), over the same follow-up period.\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eContinuous variables were reported as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD). Categorical variables were reported as percentage (%). Postoperative changes in continuous variables compared to baseline were assessed using paired Student\u0026rsquo;s t-tests. Weight loss was reported as %TWL, calculated as (pre-procedural weight \u0026ndash; post-procedural weight)/pre-procedural weight x 100. A p-value of \u0026le;\u0026thinsp;0.05 was considered statistically significant. The statistical analyses were performed using SAS OnDemand for Academics (Cary, NC).\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eBaseline Characteristics and Procedural Details\u003c/h2\u003e \u003cp\u003eA total of 14 subjects were enrolled. The mean baseline age was 48\u0026thinsp;\u0026plusmn;\u0026thinsp;9 years, and 7 of the 14 subjects (50%) were female. The mean baseline BMI was 40.4\u0026thinsp;\u0026plusmn;\u0026thinsp;3.7 kg/m\u003csup\u003e2\u003c/sup\u003e, and the mean HbA1c was 8.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3%. The average duration of T2DM was 4.8\u0026thinsp;\u0026plusmn;\u0026thinsp;2.0 years.\u003c/p\u003e \u003cp\u003eThe technical success rate was 100% (14/14). The mean procedural time was 68\u0026thinsp;\u0026plusmn;\u0026thinsp;20 minutes, and the mean time from enterostomy to magnet coupling was 43\u0026thinsp;\u0026plusmn;\u0026thinsp;18 minutes. There were no adverse events. Patients were discharged home on post-operative day 1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eOutcomes\u003c/h2\u003e \u003cp\u003eAt 12, 24, 36 and 48 months, there were significant reductions in HbA1c from the baseline value of 8.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3% to 6.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6%, 6.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2%, 6.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5% and 6.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.8%, respectively (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05 compared to baseline for all) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea). Weight also decreased significantly from 113\u0026thinsp;\u0026plusmn;\u0026thinsp;22 kg at baseline to 98\u0026thinsp;\u0026plusmn;\u0026thinsp;26 kg, 96\u0026thinsp;\u0026plusmn;\u0026thinsp;27 kg, 96\u0026thinsp;\u0026plusmn;\u0026thinsp;31 kg, and 102\u0026thinsp;\u0026plusmn;\u0026thinsp;29 kg at 12, 24, 36 and 48 months, respectively (p\u0026thinsp;\u0026lt;\u0026thinsp;0.01 compared to baseline for 12, 24, and 36 months; p\u0026thinsp;=\u0026thinsp;0.09 at 48 months) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb). These corresponded to total weight loss of 13.4\u0026thinsp;\u0026plusmn;\u0026thinsp;8.6%, 14.2\u0026thinsp;\u0026plusmn;\u0026thinsp;11.5%, 15.6\u0026thinsp;\u0026plusmn;\u0026thinsp;13.6%, and 13.5\u0026thinsp;\u0026plusmn;\u0026thinsp;12.9%, respectively (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0005 compared to baseline for all).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThis prospective study demonstrated the safety, efficacy, and durability of the SNAP procedure in improving both T2DM and obesity for up to at least four years. Specifically, HbA1c decreased by 1.9% at one year and remained at a 1.4% reduction at four years, both of which are considered clinically significant. Patients also achieved a TWL of 13.4% at one year and maintained this weight loss at four years.\u003c/p\u003e \u003cp\u003eThe SNAP procedure represents an evolution in metabolic and bariatric surgery, combining laparoscopic and endoscopic techniques to provide a technically simpler and less invasive treatment option for patients with obesity and metabolic diseases. Anatomically, SNAP resembles the small bowel component of the single-anastomosis duodeno-ileal bypass (SADI), which is an alternative to the traditional biliopancreatic diversion with duodenal switch (BPD-DS), but without the sleeve gastrectomy component. In SADI, a single end-to-side anastomosis is created between the transected duodenum and the ileum approximately 300 cm proximal to the ileocecal valve\u003csup\u003e8\u003c/sup\u003e. In contrast, SNAP creates a side-to-side duodenal-ileal anastomosis using magnet coupling instead of stapling or hand-sewing, which may reduce the risks of bleeding or anastomotic leaks. Additionally, because the duodenum is not transected in SNAP, the natural enteral continuity of the distal duodenum, jejunum, and proximal ileum is preserved. As a result, nutrients can pass through both the natural route and the newly created diverted channel, unlike in SADI, where nutrient flow is directed exclusively through the new anastomosis.\u003c/p\u003e \u003cp\u003eFrom a metabolic effectiveness standpoint, the SNAP procedure appears to provide benefits comparable to those of SADI. Specifically, as shown in this study, SNAP was associated with an average HbA1c reduction of 1.9% at one year and 1.4% at four years. For SADI, published studies report average HbA1c reductions of approximately 2% at one year and 1.8% at five years\u003csup\u003e8\u003c/sup\u003e. The metabolic benefits of SADI are thought to result from both the foregut and hindgut hypotheses\u003csup\u003e9\u003c/sup\u003e. The foregut hypothesis proposes that excluding nutrients from the proximal small intestine suppresses signals that promote insulin resistance and T2DM. In contrast, the hindgut hypothesis suggests that accelerating the delivery of undigested nutrients to the distal small intestine stimulates greater secretion of incretin hormones, which improve insulin sensitivity and lower blood glucose levels. For SNAP, the mechanism of metabolic benefit is likely driven primarily by the hindgut hypothesis, as nutrients can rapidly pass through the newly created duodeno-ileal anastomosis to the ileum and colon, with a marginal contribution from the foregut hypothesis due to reduced nutrient exposure in the proximal small bowel.\u003c/p\u003e \u003cp\u003eThe metabolic improvement observed following SNAP appears to be disproportionate to the amount of weight loss when compared to the SADI procedure, suggesting a possible weight-independent metabolic effect of SNAP. Specifically, while the HbA1c reduction following SNAP was similar to that reported for SADI, SNAP was associated with approximately 13\u0026ndash;15% TWL, compared to about 30% TWL for SADI\u003csup\u003e8\u003c/sup\u003e. This difference is likely due to the absence of a sleeve gastrectomy component and the lack of complete exclusion of the proximal small bowel in SNAP. Nevertheless, it is noteworthy that despite the lower weight loss achieved with SNAP, the degree of metabolic improvement was comparable to that of SADI, highlighting the potential role of weight-independent mechanisms. Given the technical simplicity and its substantial metabolic effect, this suggests that SNAP could be considered for patients with metabolic disease and lower BMI, such as those with class I obesity, for whom traditional bariatric surgery is often not considered or covered by insurance due to its benefit-to-risk ratio.\u003c/p\u003e \u003cp\u003eThis study has a few limitations. First, the sample size was relatively small; however, statistically significant differences were observed in both clinical outcomes (HbA1c reduction and weight loss). Additionally, the absence of a control arm may have introduced bias and limited the ability to attribute the observed effects solely to the SNAP procedure.\u003c/p\u003e \u003cp\u003eIn conclusion, SNAP appears to be associated with sustained improvements in T2DM and obesity, with effects lasting up to at least four years.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003cp\u003eP.J. has received research support from Boston Scientific, Cook Medical, Fractyl, Morphic Medical, and USGI Medical, has served as a consultant to Boston Scientific, Cook Medical, ERBE, Fractyl, Morphic Medical, Olympus, Spatz Medical, and USGI Medical, is a co-founder of Bariendo, and has received royalty from Endosim. F.S. has no conflict of interest. D.L. has stock options in GI Windows. P.R. has no conflict of interest. M.R. has received research support from Boston Scientific and Olympus, has served as a consultant to Boston Scientific, Cook Medical, FujiFilm, Olympus, Medtronic, Enterasense, GI Windows, and has stock options in Enterasense and GI Windows. C.T. has served as a consultant for Boston Scientific, Endoquest Robotics, Enterasense, Enterra Medical, EnVision Endoscopy, Fractyl, Fujifilm, USGI Medical, Medtronic/Covidien, Olympus/Spiration, Softac, USGI Medical, Xenter and Morphic Medical, has served as an advisory boards member for USGI Medical and Fractyl, has received research grant and support from USGI Medical, Boston Scientific, ERBE, Fractyl, FujiFilm, Olympus/Spiration, Endoquest Robotics, GIE Medical and Morphic Medical, has served as a general partners for Blueframe Healthcare, Puma and Bioventures MedTech Funds, has served as a founder for Bariendo, Enterasense, EnVision Endoscopy and GI Windows, holds ownership interest for GI Windows, Xenter, EnVision Endoscopy, Enterasense and Softac and has received royalty from Endosim. R.B. has no conflict of interest.\u003c/p\u003e\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eP.J. and P. R. wrote the main manuscript text and P.J. prepared figures 1-3. All authors reviewed the manuscript\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eDe Luca M, Shikora S, Eisenberg D, et al. Scientific evidence for the updated guidelines on indications for metabolic and bariatric surgery (IFSO/ASMBS). Surg Obes Relat Dis Off J Am Soc Bariatr Surg 2024;20:991–1025.\u003c/li\u003e\n\u003cli\u003eCirera de Tudela A, Vilallonga R, Ruiz-Úcar E, et al. Management of Leak after Single Anastomosis Duodeno-Ileal Bypass with Sleeve Gastrectomy. J Laparoendosc Adv Surg Tech A 2021;31:152–160.\u003c/li\u003e\n\u003cli\u003eBrown WA, de Leon Ballesteros GP, Ooi G, et al. Single Anastomosis Duodenal-Ileal Bypass with Sleeve Gastrectomy/One Anastomosis Duodenal Switch (SADI-S/OADS) IFSO Position Statement-Update 2020. Obes Surg 2021;31:3–25.\u003c/li\u003e\n\u003cli\u003eArau RT, Ortega A, Diez-Caballero A, et al. Duodeno-ileal diversion with self-forming magnets in a sutureless neodymium anastomosis procedure (SNAP) for weight recidivism after sleeve gastrectomy: feasibility and 9-month results. Surg Endosc 2024;38:5199–5206.\u003c/li\u003e\n\u003cli\u003eOlavarria OA, Chhabra KR, Levi ST, et al. Small bowel magnetic compression anastomosis creation for bypass procedures in a porcine model. Surg Endosc 2025;39:2155–2163.\u003c/li\u003e\n\u003cli\u003eBhandari M, Neto MG, Brunaldi VO, et al. Immediately-Patent Magnetic Duodeno-Ileal Anastomosis (IMPA-DI): The First-in-Human Study. Obes Surg 2025;35:2053–2058.\u003c/li\u003e\n\u003cli\u003eSchlottmann F, Ryou M, Lautz D, et al. Sutureless Duodeno-Ileal Anastomosis with Self-Assembling Magnets: Safety and Feasibility of a Novel Metabolic Procedure. Obes Surg 2021;31:4195–4202.\u003c/li\u003e\n\u003cli\u003eTopart P, Becouarn G. The single anastomosis duodenal switch modifications: a review of the current literature on outcomes. Surg Obes Relat Dis Off J Am Soc Bariatr Surg 2017;13:1306–1312.\u003c/li\u003e\n\u003cli\u003eMingrone G, Castagneto-Gissey L. Mechanisms of early improvement/resolution of type 2 diabetes after bariatric surgery. Diabetes Metab 2009;35:518–523.\u003c/li\u003e\n\u003cli\u003eRisstad H, Kristinsson JA, Fagerland MW, et al. Bile acid profiles over 5 years after gastric bypass and duodenal switch: results from a randomized clinical trial. Surg Obes Relat Dis Off J Am Soc Bariatr Surg 2017;13:1544–1553.\u003c/li\u003e\n\u003cli\u003eWang W, Cheng Z, Wang Y, et al. Role of Bile Acids in Bariatric Surgery. Front Physiol 2019;10:374.\u003c/li\u003e\n\u003cli\u003eRubino F, Forgione A, Cummings DE, et al. The mechanism of diabetes control after gastrointestinal bypass surgery reveals a role of the proximal small intestine in the pathophysiology of type 2 diabetes. Ann Surg 2006;244:741–749.\u003c/li\u003e\n\u003cli\u003eJørgensen NB, Dirksen C, Bojsen-Møller KN, et al. Exaggerated glucagon-like peptide 1 response is important for improved β-cell function and glucose tolerance after Roux-en-Y gastric bypass in patients with type 2 diabetes. Diabetes. 2013;62:3044–3052.\u003c/li\u003e\n\u003cli\u003e•\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"obesity-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"obsu","sideBox":"Learn more about [Obesity Surgery](https://link.springer.com/journal/11695)","snPcode":"11695","submissionUrl":"https://submission.springernature.com/new-submission/11695/3","title":"Obesity Surgery","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-7887832/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7887832/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eSingle-anastomosis duodenal-ileal bypass and duodeno-ileal bipartition are effective metabolic surgeries but remain technically demanding due to the complexity and risk of duodeno-ileal anastomotic leaks.. Magnetic compression anastomosis using Self-Forming Magnets (SFM) offers a simplified, sutureless alternative that may reduce procedural risk. This study evaluated the feasibility, safety, and four-year outcomes of the SFM Sutureless Neodymium Anastomosis Procedure (SNAP) in patients with obesity and type 2 diabetes mellitus (T2DM).\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis prospective, single-center study included patients with obesity and T2DM. The SNAP technique involved endoscopic and laparoscopic deployment of SFMs to create a duodeno-ileal anastomosis without sutures or staples. Primary endpoint was change in hemoglobin A1c (HbA1c) through 48 months. Secondary endpoints included percent total weight loss (%TWL) and safety outcomes.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eFourteen patients (age 48\u0026thinsp;\u0026plusmn;\u0026thinsp;9 years; 50% female; baseline BMI 40.4\u0026thinsp;\u0026plusmn;\u0026thinsp;3.7 kg/m\u0026sup2;) underwent successful SNAP creation (technical success 100%). Mean procedural time was 68\u0026thinsp;\u0026plusmn;\u0026thinsp;20 minutes. No adverse events occurred. HbA1c significantly decreased from 8.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3% to 6.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6%, 6.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2%, 6.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5%, and 6.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.8% at 12, 24, 36, and 48 months, respectively (all p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Corresponding %TWL was 13.4\u0026thinsp;\u0026plusmn;\u0026thinsp;8.6%, 14.2\u0026thinsp;\u0026plusmn;\u0026thinsp;11.5%, 15.6\u0026thinsp;\u0026plusmn;\u0026thinsp;13.6%, and 13.5\u0026thinsp;\u0026plusmn;\u0026thinsp;12.9%.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eSFM-assisted duodeno-ileal bipartition using the SNAP technique is feasible, safe, and durable, producing clinically meaningful and sustained weight loss and glycemic improvement over four years. This magnet-based, sutureless approach may represent a less invasive alternative to conventional duodeno-ileal anastomosis in metabolic surgery.\u003c/p\u003e","manuscriptTitle":"Four-Year Outcomes of Duodeno-Ileal Bipartition Using Self-Forming Magnets: The Sutureless Neodymium Anastomosis Procedure (SNAP) for Obesity and Type 2 Diabetes","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-20 08:15:18","doi":"10.21203/rs.3.rs-7887832/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-01-22T18:29:20+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-18T17:58:34+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-17T13:49:48+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-14T20:48:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"326908313403145998738710997913819152911","date":"2026-01-14T16:36:22+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"62809768753342553591312388751513172418","date":"2026-01-14T11:59:00+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"310548731682561980486522937422402348925","date":"2026-01-14T05:18:30+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-01-14T03:56:30+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-22T01:40:26+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-21T23:55:49+00:00","index":"","fulltext":""},{"type":"submitted","content":"Obesity Surgery","date":"2025-10-17T14:47:22+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"obesity-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"obsu","sideBox":"Learn more about [Obesity Surgery](https://link.springer.com/journal/11695)","snPcode":"11695","submissionUrl":"https://submission.springernature.com/new-submission/11695/3","title":"Obesity Surgery","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"c5269e74-34ec-4407-b2ae-501d69d9cc3e","owner":[],"postedDate":"January 20th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-09T19:23:57+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-20 08:15:18","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7887832","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7887832","identity":"rs-7887832","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}