Efficacy of argon plasma coagulation (APC) in the reduction of gastrojejunal anastomosis for weight regain after Roux-en-Y gastric bypass

Efficacy of argon plasma coagulation (APC) in the reduction of gastrojejunal anastomosis for weight regain after Roux-en-Y gastric bypass | 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 Efficacy of argon plasma coagulation (APC) in the reduction of gastrojejunal anastomosis for weight regain after Roux-en-Y gastric bypass Clara Rodriguez Carrillo, Sara Mera Carreiro, Rafael Sánchez del Hoyo, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6956733/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract BACKGROUND & AIMS Argon plasma coagulation (APC) is effective in the reduction of gastrojejunal anastomosis (GJA) for weight regain after Roux-en-Y gastric bypass (RYGB). This study aims to confirm the efficacy of APC in treating weight regain following RYGB surgery and to analyse factors associated with treatment success. PATIENTS AND METHODS Single-center retrospective study of 36 RYGB patients who underwent APC for weight regain from 2018 to 2023. Percentage total weight loss (%TWL) was analyzed as the primary outcome and reduction in anastomosis diameter (RAD), comorbidities, and adverse events (AE) were evaluated as secondary outcomes. Patients were classified according to %TWL categories of ≥5%, ≥10% or ≥15% and were followed up at 3, 6 and 12 months. Patients with ≥5% TWL at 3 months were considered responders. The relationship between %TWL and age, sex, changes in BMI and comorbidities was analyzed. RESULTS Over 60% of patients lost ≥5% TWL at 3, 6 and 12 months, with no statistical association with RAD. TWL for responders was 14,9%, 11,7% and 11,1% at 3, 6, 12 months respectively with statistical differences compared to non-responders. No clinically significant associations were found between pre-treatment factors and subsequent weight loss. At 12 months, over 80% of patients maintained ≥5% of TWL, and over half achieved a TWL of ≥10%. Mean BMI in responders was 31.68 ± 0.1; and over a quarter (27.3%) of them achieved a final BMI of less than 30, which could be considered a significant success, as these patients would no longer be classifed as obese. Technical success was 100%. Only 3(8%) AEs were registered, withmild anastomotic stenosis occuring most commonly. CONCLUSIONS: APC is a simple and effective technique for inducing weight loss after RYGB, with beneficial results observed in at least 60% of patients in this study. obesity surgery Roux-en-Y gastric bypass weight regain argon plasma coagulation Figures Figure 1 Figure 2 Figure 3 1. INTRODUCTION Obesity is highly prevalent in developed countries, and is associated with high medical costs. Bariatric surgery is an effective treatment for obesity with Roux-en-Y gastric bypass(RYGB) being one of the most commonly performed procedures. However, about 20% of patients experience weight regain in the long term following this procedure (1) (2). This is a significant issue due to the medical conditions associated with obesity and metabolic syndrome. Factors contributing to the failure of RYGB can be divided into non-surgical and surgical categories(3). Non-surgical factors include behavioral changes such as physical inactivity, low self-esteem, and eating disorders. Surgical causes primarily involve pouch dilation and the widening of the GJA (4). The enlargement of the GJA is a key issue and may be linked to rapid gastric emptying (5,6). Several endoscopic procedures have been reported to reduce the diameter of the GJA (7–11). Argon plasma coagulation (APC) is a non-contact endoscopic technique that delivers radiofrequency energy to tissue via ionized argon gas and an electric current. This method induces a progressive reduction in the diameter of GJA, promoting early satiety and potentially leading to weight loss (12). The objective of this study is to evaluate the efficacy of APC in reducing GJA diameter for the management of weight regain following RYGB and to identify potential predictive factors associated with greater TWL. 2. PATIENTS AND METHODS 2.1.- Design study and participants A retrospective study was conducted at a tertiary care center in Spain, including 59 patients who underwent endoscopic GJA reduction with APC between 2018 and 2023. Of these, 23 patients were excluded because the primary indication for the procedure was dumping syndrome in the absence of significant weight regain. Although this study was conducted retrospectively, all data were prospectively collected during the study period. Approval for human subject research was obtained from the Institutional Review Board of the local ethics committee (C.I. 24/011-E), and informed consent was obtained from all participants, in accordance with the principles of the Declaration of Helsinki. Inclusion criteria comprised adult patients with a history of RYGB performed for obesity who experienced weight regain exceeding 10% from the nadir and had not achieved satisfactory results with dietary and/or pharmacological interventions. Patients with persistent weight gain were deemed eligible for the APC procedure if the GJA diameter exceeded 15 mm. Clinical data were extracted from electronic medical records, including patient demographics (age, sex), body mass index (BMI) at baseline (prior to RYGB), at nadir weight, and at the time of the endoscopic procedure. Additional variables included time since initial surgery and percentage of weight loss following APC treatment. 2.2.- Endoscopic procedure All interventions were carried out by a single endoscopist. Prior to the procedure, patients underwent a fasting period of 12 hours and were then admitted to the endoscopy unit. Sedation was administered with a propofol-based regimen under the supervision of an anesthesiologist, and patients were placed in the left lateral decubitus position. The procedure was performed using an Olympus CV-1500 gastroscope with assessment of the gastrojejunal anastomosis diameter pre- and post treatment using a flexible anastomosis measurement device. Argon plasma coagulation (APC) was applied using an ERBE USA APC™ disposable probe (2.3 mm outer diameter / 6.9 Fr, 220 cm in length). The argon plasma was delivered circumferentially around the GJA at a flow rate of 0.8 L/min and power setting of 80 watts. The procedure took approximately 15 minutes Following the intervention, patients were monitored in the recovery area for one hour before being discharged the same day. Post-procedure care involved a soft diet for two weeks, restricted fluid intake, use of proton pump inhibitors (PPIs), and pain management with analgesics as needed. Patients underwent between one and four consecutive APC sessions, depending on the final anastomotic diameter. Follow-up visits were scheduled monthly at a specialized endocrine clinic for the first six months post-procedure, and subsequently every 3–6 months. During follow-up visits, body weight, clinical history, and physical examination findings were recorded. Selected patients underwent additional APC sessions as clinically indicated. 2.3.- Statistical analysis Continuous variables were summarized as mean ± standard deviation (SD), while categorical variables were expressed as percentages. Comparisons between continuous variables were performed using the independent sample t-test, whereas the Mann-Whitney U test was applied for variables with a skewed distribution. The Chi-square test was used to analyze categorical data. Statistical analyses were conducted using the Statistical Package for Social Sciences (IBM® SPSS, version 26.0) and JASP (version 0.18.1, 2023). 3. RESULTS 3.1. Demographic, anthropometric, clinical evaluation and adverse events. A total of 36 patients were included in the study, of whom 77.8% were women. The mean age was 43.95 ± 10 years. The mean pre-surgical weight was 122.68 ± 13 kg, with a mean body mass index (BMI) of 45.5 ± 4.4 kg/m². The presence of medical comorbidities including diabetes, hypertension, dyslipidemia, obstructive sleep apnea syndrome (OSAS), and eating behavior disorders (EBD), was recorded (Table 1 ). Following RYGB, the mean nadir BMI was 29.83 ± 3.5 kg/m², corresponding to a TWL of 38.17 ± 6.51%. At the time of endoscopic intervention, the mean weight had increased to 97.15 ± 15 kg, with a BMI of 36.02 ± 5.2 kg/m². Regarding the APC treatment, 11 patients (30.6%) required 1–2 sessions, while 25 patients (69.4%) underwent 3–4 sessions. No patient received more than four APC sessions. Adverse events (AEs) occurred in three patients (8%): two cases of GJA stenosis and one case of GJA ulceration. All AEs were classified as mild. Both cases of stenosis were successfully managed with endoscopic dilation, while the ulceration resolved without the need for endoscopic intervention. Table 1 Demographic and anthropometric profile of patients submitted to GJA reduction with APC. BMI: Body mass index. OSAS: Obstructive sleep apnea syndrome. EBD: Eating behaviour disorder. Quantitative variables Mean ± SD Anthropometric profile Height (m) 1.64 ± 0.07 Pre-surgery weight (kg) 122.68 ± 13 Pre-surgery BMI (kg/m 2 ) 45.51 ± 4.49 Nadir BMI (kg/m 2 ) 29.83 ± 3.5 Pre-APC BMI (kg/m 2 ) 36.02 ± 5.2 Demographic variables Age 43.95 ± 10 Qualitative variables N (%) Sex Women (n/%) 28 (77,8) Men (n/%) 8 (22.2) Patient comorbidities Any 19 (52.7) Type 2 Diabetes mellitus (DM) 5 (13.9) Hypertension 7 (19.4) Dyslipidemia 5 (13.9) OSAS 9 (25) EBD 5 (13.9) 3.2. Gastrojejunal anastomosis (GJA) diameter The mean GJA diameter before the procedure was 26.6 ± 5.4 mm, decreasing to an average of 16.4 ± 5.0 mm (p < 0.001). A total of 72% (n = 26) of patients achieved a small final GJA diameter of < 18 mm. The absolute reduction in anastomosis diameter (RAD) was 10.22 ± 6.39 mm, corresponding to a 36.9 ± 19.3% reduction. 3.3. Total weight loss (TWL). TWL was assessed at three time points: short-term (3 months), mid-term (6 months), and long-term (12 months). The mean absolute TWL (%) was 8.3 ± 7.1% at 3 months, 8.0 ± 6.6% at 6 months, and 8.2 ± 8.6% at 12 months. BMI (kg/m2) declined from 36.02 ± 5.2 pre-APC to 32.91 ± 4.7 at 12 month (p < 0.01). Additionally, TWL was analyzed categorically using predefined thresholds (≥ 5%, ≥ 10%, and ≥ 15%) at all time points (Fig. 1). More than 60% of patients achieved at least 5% TWL across all follow-up periods. The proportion of patients achieving ≥ 10% TWL was lower, with 33.3% at 3 months, 33.3% at 6 months, and 38.9% at 12 months. A smaller subset of patients achieved ≥ 15% TWL: 19.4% at 3 months, 13.9% at 6 months, and 16.7% at 12 months. Absolute TWL was compared across all predefined categories (≥ 5%, ≥ 10%, and ≥ 15%) at short-term (3 months), mid-term (6 months), and long-term (12 months) follow-up using the McNemar test. No statistically significant differences were observed between the groups. 3.4. Possible variables associated with TWL The study aimed to identify variables associated with greater absolute TWL. As the most significant weight loss was observed in the short-term period, analyses were focused on this time point. Absolute TWL at 3 months was compared across different patient comorbidities, demographic characteristics, and anthropometric profiles. The potential influence of the number of APC sessions on TWL was also evaluated by dividing patients into two groups: Patients who underwent 1–2 sessions and patients who underwent 3–4 sessions. Quantitative variables were correlated with TWL at 3 months using Spearman’s Rho test, revealing a weak correlation (ρ = 0.163). For qualitative variables, comparisons were conducted using the Mann-Whitney U test. No significant differences were found in TWL among patients with the following comorbidities: hypertension, diabetes, dyslipidemia, obstructive sleep apnea, and eating disorders. Additionally, no association was found between the number of APC sessions and TWL at any follow-up period. Statistical analyses of the variables were performed using Spearman’s Rho and the Mann-Whitney U test, as detailed in Table 2 . Table 2 Relation between different variables and absolute TWL at 3 months. Variable 3m TWL Quantitative variables. Spearmans’ Rho test % RAD Rho value 0.163 Basal BMI Rho value 0.27 Age Rho value 0.152 Qualitative variables. U- Mann-Whitney test Sex (f/m) P value 0.819 Comorbidities (y/n) P value 0.558 DM P value 0.262 Hypertension P value 0.105 Dyslipemia P value 0.697 OSAS P value 0.674 EBD P value 0.567 Nª APC (1–2 / 3–4) P value 0.986 RAD: Reduction in Anastomosis Diameter. BMI: Body Mass Index. DM: Diabetes melitus. OSAS: Obstructive Sleep Apnea Syndrome. EBD: Eating behaviour Disorder. SD: Standard Deviation. 3.5. APC-responders and possible associated factors, In the short term (3 months), 22 patients (61%) achieved a ≥ 5% total weight loss (TWL) and were classified as ‘responders’ to the APC procedure. In contrast, 14 patients (39%) experienced < 5% TWL and were considered ‘non-responders.’ Unlike non-responders, the responder group demonstrated sustained weight loss at both medium- and long-term follow-up. Maximum weight loss was observed between 3 and 6 months following APC. Responders achieved a TWL of nearly 15%, whereas non-responders reached a maximum of 5.4%. These outcomes are illustrated in Fig. 2 . TWL at 12 months was analyzed in both groups. Among responders, more than 80% of patients maintained a weight loss of ≥ 5% of total body weight, and over 50% achieved a TWL of ≥ 10%. In contrast, only one-third of non-responders attained a TWL of ≥ 5%. These results are illustrated in Fig. 3 . At 12 months, the mean BMI in non-responders was 34.8 ± 5.1, whereas in responders, it was 31.7 ± 4.1 with statistical differences (p = 0.049). Notably, over a quarter (27.3%) of responders achieved a final BMI of less than 30, which may be considered a significant clinical success. To identify predictive factors associated with response to the APC procedure, various variables were analyzed between both groups. Mean values were calculated for most variables, except for the reduction in GJA diameter, where median values along with the interquartile range (25th and 75th percentiles) are reported. The P-value was determined using the Chi-square test (or Fisher’s exact test) and the Student's t-test; however, no statistically significant differences were observed. The results are presented in Table 3 . Table 3 Variables in the responder and non-responder group. All values correspond with mean value ± SD, except reduction in GJA diameter (median value is shown with interquartile 25th − 75th range). BMI: Body Mass Index. APC: Argon Plasma Coagulation . RAD: Reduction in anastomosis diameter. GJA: Gastroyeyunal anastomosis. RYGB: Roux-en-Y Gastric Bypass, TWL: Total weight loss. IQR : interquartile range. Category Non-responders: Patients with TWL < 5% at 3m Responders: Patients with TWL ≥ 5% at 3m p value 14 /36 ( 39% ) 22 /36 ( 61% ) Demographic variables Sex: Female 11/14 (78.6%) 17/22 (77.3%) 0.631 Sex: Male 3/14 (21.4%) 5/22 (22.7%) Age (years) 44.8 ± 12.2 43.4 ± 8.6 0.768 Weight BMI before RYGB (kg/m2) 44.5 ± 5 46.2 ± 4.1 0.270 BMI NADIR post-RYGB (kg/m2) 28.4 ± 4.6 27.8 ± 2.8 0.654 BMI before APC (kg/m2) 36.3 ± 5.2 35.9 ± 5.5 0.824 BMI 1 year post-APC (kg/m2) 34.8 ± 5.1 31.7 ± 4.1 0.049 Weight regain after RYGB (%) 22.5 ± 11 21.4 ± 9.4 0.761 BMI (kg/m2) 3 months 35.8 ± 5.2 31.3 ± 5 0.015 BMI (kg/m2) 6 months 34.6 ± 5.7 32.1 ± 4.3 0.263 BMI (kg/m2) 12 months 34.8 ± 5.1 31.7 ± 4.1 0.092 Procedure and GJA diameter Number of APC procedures (median) 3 3 0.557 Baseline GJA diameter (mm) 26.5 ± 5 26.7 ± 5.7 0.923 Final GJA diameter (mm) 15.8 ± 4.8 16.8 ± 5.3 0.577 Small final GJA (< 18mm) 11/14 (78.6%) 15/22 (68.2%) 0.706 RAD (mm) median (IQR) -10 (-14.3,-5.3) -10 (-14.3, -4) 0.896 RAD (%) median (IQR) -39.3 (-50,-23) -33.8 (-54.3, -19.2) 0.808 4. DISCUSSION This retrospective study highlights the efficacy of APC, demonstrating significant TWL at all time points in patients who experienced weight regain following RYGB. Initially, all patients experienced some degree of weight loss after the APC intervention. However, when grouped by TWL, weight regain appears to be a common trend among the majority of patients, with only 13.9% and 16.7% maintaining a TWL of ≥ 15% at the medium and long-term follow-ups, respectively. This underscores the chronic nature of obesity, with weight regain being influenced by various behavioural factors. It also suggests that the effects of APC may be inconsistent over the long term. Nonetheless, our results regarding TWL are noteworthy, with a loss of 7.96% (± 6.57) at 6 months. This is consistent with other studies, such as that of Moon et al. (13), who analysed 588 patients undergoing APC in bariatric centres and reported a %TWL of 6.7 ± 0.3 at 6 months. A clear distinction in APC response between responders and non-responders was evident as early as 3 months, leading to the classification of patients as ‘responders’ (≥ 5% TWL) and ‘non-responders’ (< 5% TWL). At 3 months, responders achieved a total weight loss nearly 10 times greater than that of non-responders. By 6 months, responders still maintained twice the TWL compared to non-responders. In our analysis, we were unable to identify any specific clinical or endoscopic variables—such as baseline anastomosis diameter, GJA diameter reduction, or early response to therapy—that could reliably predict the degree of success following APC treatment. This suggests that the variability in weight loss outcomes may not be solely attributable to anatomical or procedural factors. One important consideration is that, while all patients were provided with standardized nutritional guidelines following the intervention, adherence to these recommendations was not systematically assessed. It is therefore possible that differences in patient compliance with dietary instructions may have contributed to the heterogeneity in long-term outcomes. This limitation highlights the need for improved strategies to monitor and support post-procedural behavioral adherence in future studies. Early weight loss at 3 months—specifically a TWL ≥ 5%—appears to be a reliable predictor of greater long-term weight reduction. This finding suggests that early response to APC may serve as a useful clinical marker to stratify patients based on expected treatment benefit. Conversely, for those classified as non-responders at 3 months, it may not be necessary to prolong observation before considering alternative therapeutic strategies. In such cases, timely initiation of adjunctive treatments, including pharmacologic therapy or endoscopic options such as endoscopic suturing (TORe) (14), could be more effective in optimizing outcomes and preventing further weight regain. Regarding the mean BMI at 12-month follow-up, over a quarter (27.3%) of responders achieved a final BMI of less than 30, which could be considered a significant success, as these patients were no longer classified as obese. Moreover, no significant differences were found in demographics, weight loss, or GJA diameter between the two groups. This is likely due to the relatively small number of patients included in the study. In these groups, factors such as age, BMI before the procedure, and the size of the anastomosis at the end of the APC were not associated with greater weight loss. While significant lifestyle changes may have contributed to greater weight loss after APC, the recording of nutritional and physical activity data during follow-up did not reveal any significant differences between the two response groups. A prospective study comparing various endoscopic bariatric procedures suggested that multidisciplinary team (MDT) follow-up plays a more crucial role in weight loss than the specific type of endoscopic procedure itself (15). Regarding patients' comorbidities and their relationship with TWL, the reduced sample size was a significant limitation. Only five patients were included for each of the following comorbidities: diabetes mellitus (DM), dyslipidemia, and esophageal bowel dysmotility (EBD). Additionally, only nine patients had OSA. In contrast, hypertension was a prevalent comorbidity, observed in 29 (80.5%) patients. In conclusion, no clinically significant associations were found between any pre-treatment factors and subsequent weight loss. This includes demographic data, BMI evolution, comorbidities, or the anatomical changes of the gastrojejunal anastomosis following the APC procedure. On the other hand, it has been demonstrated (16) that a higher power APC setting is associated with a deeper tissue effect. Specifically, a high dose (considered as 70-80W) has been shown to be superior to a low dose (45-55W) in the treatment of weight regain (16). In this study, all patients received a high dose of 80W. However, other variables, such as the duration of APC and the distance between the probe and the tissue, may also contribute to this effect; although these factors cannot be accurately monitored. According to the literature (17,18), TWL appears to be a consequence of GJA reduction. When analysing GJA reduction, the raw results are considerable: the GJA size was reduced by a third (%RAD 36.86%), which corresponds to a 10mm reduction. Patients had a dilated GJA, with a mean pre-APC GJA diameter of 26.61 ± 5.41mm. Contrary to expectations, neither the RAD nor the GJA diameter were found to be predictors of TWL. Jirapinyo et al. (16) suggested that patients with larger GJA diameters (defined as > 18mm) may respond better to alternative endoscopic therapies, such as endoscopic suturing (TORe), rather than APC. Despite the lack of a statistical association between TWL, GJA diameter, or RAD, 72% of patients achieved a smaller GJA (≤ 18mm), and nearly 60% experienced a ≥ 5% weight loss in the short term, as previously mentioned. Due to the limited number of subjects in our study, we were unable to perform a multivariate analysis to determine the strength of this relationship. However, this could be explored further in future studies. Furthermore, the number of APC sessions has been statistically associated with TWL in other studies (16). In our study, however, we found no statistical difference between the number of APC sessions and TWL. We hypothesize that individual factors, likely related to the patient's lifestyle and behavioural habits, may play a significant role in weight loss. While this aspect was not evaluated in our study, it could be explored in future research. Our results demonstrate that APC treatment for weight regain is a safe technique. The rate of adverse events was 8%, which aligns with the 3% reported in Moon et al.'s study (13). Additionally, no serious complications, such as bleeding or perforation, were observed. This is likely due to the superficial effect of APC which typically results in tissue penetration of 1 to 3mm (17). The study does have some limitations. Primarily, as a single centre study, the sample size is small, which accounts for the lack of significant associations between demographic factors, BMI, comorbidities, and TWL. However, our study has demonstrated that a simple, non-invasive method such as endoscopic APC therapy can be effective in reversing weight regain after RYGB in more than half of the patients. In conclusion, APC therapy for GJA reduction is a safe and effective treatment for weight regain, at least in the short and medium term, in 60% of patients. It is recommended that prospective studies with larger patient cohorts are conducted, incorporating additional variables associated with lifestyle changes following APC. Declarations Author Contribution C. Rodriguez Carrillo and S. Mera Carreiro wrote the main manuscript text. R. Sánchez Del Hoyo has performed all the statistical analysesM.A. Rubio Herrera is the main reviewer of the article, although all authors have contributed to its revision. References Magro DO, Geloneze B, Delfini R, Pareja BC, Callejas F, Pareja JC. Long-term weight regain after gastric bypass: a 5-year prospective study. Obes Surg. 2008;18(6):648-51. Adams TD, Davidson LE, Litwin SE, Kim J, Kolotkin RL, Nanjee MN. Weight and Metabolic Outcomes 12 Years after Gastric Bypass. N Engl J Med. 2017;377:1143-55. 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Peroral endoscopic reduction of dilated gastrojejunal anastomosis after Roux-en-Y gastric bypass: a possible new option for patients with weight regain. Surg Endosc. 2006;20(11):1744-8. Mikami D, Needleman B, Narula V. Natural orifice surgery: initial US experience utilizing the StomaphyX device to reduce gastric pouches after Roux-en-Y gastric bypass. Surg Endosc. 2010;24(1):223-8. Thompson CC, Jacobsen GR, Schroder GL. Stoma size critical to 12-month outcomes in endoscopic suturing for gastric bypass repair. Surg Obes Relat Dis. 2012;8(3):282-7. Heylen AM, Jacobs A, Lybeer M. The OTSC(R)-clip in revisional endoscopy against weight gain after bariatric gastric bypass surgery. Obes Surg. 2011;21(10):1629-33. Baretta GA, Alhinho HC, Matias JE. Argon plasma coagulation of gastrojejunal anastomosis for weight regain after gastric bypass. Obes Surg. 2015;25(1):72-9. Moon, R.C., Texeira, A.F, Neto, M.G. Efficacy of Utilizing Argon Plasma Coagulation for Weight Regain in Roux-en-Y Gastric Bypass Patients: a Multi-center Study. 2018;28(9):2737-44. Szvarca D, Jirapinyo P. Endoscopic Management of Weight Regain After Bariatric Surgery. Gastrointest Endosc Clin N Am. 2024;34(4):639-54. Lopez-Nava G, Asokkumar R, Rull A, Corbelle F, Beltran L, Bautista I. Bariatric endoscopy procedure type or follow-up: What predicted success at 1 year in 962 obese patients? Endosc Int Open. 2019;07(12):E1691-8. Jirapinyo, P, Moura D, Dong W. Dose response for argon plasma coagulation in the treatment of weight regain after Roux-en-Y gastric bypass. Gastrointest Endosc. 2020;91(5):1078-84. Flanagan L. Measurement of functional pouch volume following the gastric bypass procedure. Obes Surg. 1996;6(1):38-43. Müller MK, Wildi S, Scholz T. Laparoscopic pouch resizing and redo of gastro-jejunal anastomosis for pouch dilatation following gastric bypass. Obes Surg. 2005;15(8):1089-95. 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Carlos","correspondingAuthor":false,"prefix":"","firstName":"Sara","middleName":"Mera","lastName":"Carreiro","suffix":""},{"id":483186456,"identity":"5eaab3d0-adb9-4969-90f2-9d7b216de9c3","order_by":2,"name":"Rafael Sánchez del Hoyo","email":"","orcid":"","institution":"Hospital Clínico San Carlos","correspondingAuthor":false,"prefix":"","firstName":"Rafael","middleName":"Sánchez del","lastName":"Hoyo","suffix":""},{"id":483186457,"identity":"72feea2e-b61d-4695-8112-1bcd6c05dfd8","order_by":3,"name":"Sreecanth Sibhi Raja","email":"","orcid":"","institution":"St Mark's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Sreecanth","middleName":"Sibhi","lastName":"Raja","suffix":""},{"id":483186459,"identity":"bae60cb5-a2d4-4c9f-9d95-2f069b62765e","order_by":4,"name":"Blanca Bernaldo Madrid","email":"","orcid":"","institution":"Hospital Clínico San Carlos","correspondingAuthor":false,"prefix":"","firstName":"Blanca","middleName":"Bernaldo","lastName":"Madrid","suffix":""},{"id":483186461,"identity":"33f0efb2-a944-4f67-9432-ac40d58844ae","order_by":5,"name":"Manuel Vázquez Romero","email":"","orcid":"","institution":"Hospital Clínico San Carlos","correspondingAuthor":false,"prefix":"","firstName":"Manuel","middleName":"Vázquez","lastName":"Romero","suffix":""},{"id":483186462,"identity":"ed373451-351a-452e-b131-7a8ab1a97bfe","order_by":6,"name":"Jose Miguel Esteban López-Jamar","email":"","orcid":"","institution":"Hospital Clínico San Carlos","correspondingAuthor":false,"prefix":"","firstName":"Jose","middleName":"Miguel Esteban","lastName":"López-Jamar","suffix":""},{"id":483186463,"identity":"13bf189d-c8c5-42ca-bcf0-092c82f3f344","order_by":7,"name":"Miguel Angel Rubio Herrera","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAw0lEQVRIiWNgGAWjYJACZgYDhgR+ECuhgBQtkg0gLQZEawEpPgBiEqNFt/3sM+mCAps84/OrEz88MGCQ5xc7gF+L2Zl0M+kZBmnFZjfebpYAOsxw5uwEAloOpLFJ8xgcTtx24+wGkJYEg9uEtJx/BtGyecbZzT+I03IDassG/t5tRNpy4xmzNdAviTNu8G6zSDCQIMIv59MYbxf8sUns7z+7+eaPCht5fmkCWhBAAqxSgljlIMB/gBTVo2AUjIJRMJIAAMZIQ6nAMVmLAAAAAElFTkSuQmCC","orcid":"","institution":"Hospital Clínico San Carlos","correspondingAuthor":true,"prefix":"","firstName":"Miguel","middleName":"Angel Rubio","lastName":"Herrera","suffix":""}],"badges":[],"createdAt":"2025-06-23 12:23:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6956733/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6956733/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":86646399,"identity":"2c7ca309-d9a7-49a7-a6a8-332691e1b624","added_by":"auto","created_at":"2025-07-14 08:58:02","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":86640,"visible":true,"origin":"","legend":"\u003cp\u003eResults for categorized TWL ≥ 5%, ≥ 10% and ≥15% at 3, 6 and 12 months.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-6956733/v1/4a28607cad5cbdcec2b7fcf2.png"},{"id":86647008,"identity":"cbcc29c4-f04d-4d05-a8ce-578477c73262","added_by":"auto","created_at":"2025-07-14 09:06:02","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":79733,"visible":true,"origin":"","legend":"\u003cp\u003eResults for total weight loss (TWL) at short (3 months), medium (6 months) and long term (12 months), in responders and non-responders. \u003cem\u003eTWL: Total weight loss.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-6956733/v1/4745830c6d96208263f7feb7.png"},{"id":86647011,"identity":"e7d3d4c2-53c0-496a-acb9-e0a128c49b4f","added_by":"auto","created_at":"2025-07-14 09:06:02","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":78465,"visible":true,"origin":"","legend":"\u003cp\u003eResults for categorical \u003cstrong\u003etotal weight loss (TWL) at 12 months\u003c/strong\u003e in responders and non-responders. \u003cem\u003eTWL: Total weight loss.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-6956733/v1/703bd45046c90608f8b76678.png"},{"id":86773303,"identity":"2b44b61a-1a96-4748-98a7-4b1ff38b5b0e","added_by":"auto","created_at":"2025-07-15 12:09:11","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1018031,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6956733/v1/d51f81db-aa40-4608-bba8-2e1c224fe6e5.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eEfficacy of argon plasma coagulation (APC) in the reduction of gastrojejunal anastomosis for weight regain after Roux-en-Y gastric bypass\u003c/p\u003e","fulltext":[{"header":"1. INTRODUCTION","content":"\u003cp\u003eObesity is highly prevalent in developed countries, and is associated with high medical costs. Bariatric surgery is an effective treatment for obesity with Roux-en-Y gastric bypass(RYGB) being one of the most commonly performed procedures. However, about 20% of patients experience weight regain in the long term following this procedure (1) (2). This is a significant issue due to the medical conditions associated with obesity and metabolic syndrome.\u003c/p\u003e\u003cp\u003eFactors contributing to the failure of RYGB can be divided into non-surgical and surgical categories(3). Non-surgical factors include behavioral changes such as physical inactivity, low self-esteem, and eating disorders. Surgical causes primarily involve pouch dilation and the widening of the GJA (4). The enlargement of the GJA is a key issue and may be linked to rapid gastric emptying (5,6). Several endoscopic procedures have been reported to reduce the diameter of the GJA (7\u0026ndash;11).\u003c/p\u003e\u003cp\u003eArgon plasma coagulation (APC) is a non-contact endoscopic technique that delivers radiofrequency energy to tissue via ionized argon gas and an electric current. This method induces a progressive reduction in the diameter of GJA, promoting early satiety and potentially leading to weight loss (12).\u003c/p\u003e\u003cp\u003eThe objective of this study is to evaluate the efficacy of APC in reducing GJA diameter for the management of weight regain following RYGB and to identify potential predictive factors associated with greater TWL.\u003c/p\u003e"},{"header":"2. PATIENTS AND METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1.- Design study and participants\u003c/h2\u003e\u003cp\u003e A retrospective study was conducted at a tertiary care center in Spain, including 59 patients who underwent endoscopic GJA reduction with APC between 2018 and 2023. Of these, 23 patients were excluded because the primary indication for the procedure was dumping syndrome in the absence of significant weight regain. Although this study was conducted retrospectively, all data were prospectively collected during the study period.\u003c/p\u003e\u003cp\u003e Approval for human subject research was obtained from the Institutional Review Board of the local ethics committee (C.I. 24/011-E), and informed consent was obtained from all participants, in accordance with the principles of the Declaration of Helsinki.\u003c/p\u003e\u003cp\u003eInclusion criteria comprised adult patients with a history of RYGB performed for obesity who experienced weight regain exceeding 10% from the nadir and had not achieved satisfactory results with dietary and/or pharmacological interventions. Patients with persistent weight gain were deemed eligible for the APC procedure if the GJA diameter exceeded 15 mm.\u003c/p\u003e\u003cp\u003eClinical data were extracted from electronic medical records, including patient demographics (age, sex), body mass index (BMI) at baseline (prior to RYGB), at nadir weight, and at the time of the endoscopic procedure. Additional variables included time since initial surgery and percentage of weight loss following APC treatment.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e2.2.- Endoscopic procedure\u003c/h2\u003e\u003cp\u003eAll interventions were carried out by a single endoscopist. Prior to the procedure, patients underwent a fasting period of 12 hours and were then admitted to the endoscopy unit. Sedation was administered with a propofol-based regimen under the supervision of an anesthesiologist, and patients were placed in the left lateral decubitus position.\u003c/p\u003e\u003cp\u003eThe procedure was performed using an Olympus CV-1500 gastroscope with assessment of the gastrojejunal anastomosis diameter pre- and post treatment using a flexible anastomosis measurement device. Argon plasma coagulation (APC) was applied using an ERBE USA APC\u0026trade; disposable probe (2.3 mm outer diameter / 6.9 Fr, 220 cm in length). The argon plasma was delivered circumferentially around the GJA at a flow rate of 0.8 L/min and power setting of 80 watts. The procedure took approximately 15 minutes\u003c/p\u003e\u003cp\u003eFollowing the intervention, patients were monitored in the recovery area for one hour before being discharged the same day. Post-procedure care involved a soft diet for two weeks, restricted fluid intake, use of proton pump inhibitors (PPIs), and pain management with analgesics as needed.\u003c/p\u003e\u003cp\u003ePatients underwent between one and four consecutive APC sessions, depending on the final anastomotic diameter. Follow-up visits were scheduled monthly at a specialized endocrine clinic for the first six months post-procedure, and subsequently every 3\u0026ndash;6 months. During follow-up visits, body weight, clinical history, and physical examination findings were recorded. Selected patients underwent additional APC sessions as clinically indicated.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e2.3.- Statistical analysis\u003c/h2\u003e\u003cp\u003eContinuous variables were summarized as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD), while categorical variables were expressed as percentages. Comparisons between continuous variables were performed using the independent sample t-test, whereas the Mann-Whitney U test was applied for variables with a skewed distribution. The Chi-square test was used to analyze categorical data. Statistical analyses were conducted using the Statistical Package for Social Sciences (IBM\u0026reg; SPSS, version 26.0) and JASP (version 0.18.1, 2023).\u003c/p\u003e\u003c/div\u003e"},{"header":"3. RESULTS","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003e3.1. Demographic, anthropometric, clinical evaluation and adverse events.\u003c/h2\u003e\u003cp\u003eA total of 36 patients were included in the study, of whom 77.8% were women. The mean age was 43.95\u0026thinsp;\u0026plusmn;\u0026thinsp;10 years. The mean pre-surgical weight was 122.68\u0026thinsp;\u0026plusmn;\u0026thinsp;13 kg, with a mean body mass index (BMI) of 45.5\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4 kg/m\u0026sup2;. The presence of medical comorbidities including diabetes, hypertension, dyslipidemia, obstructive sleep apnea syndrome (OSAS), and eating behavior disorders (EBD), was recorded (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eFollowing RYGB, the mean nadir BMI was 29.83\u0026thinsp;\u0026plusmn;\u0026thinsp;3.5 kg/m\u0026sup2;, corresponding to a TWL of 38.17\u0026thinsp;\u0026plusmn;\u0026thinsp;6.51%. At the time of endoscopic intervention, the mean weight had increased to 97.15\u0026thinsp;\u0026plusmn;\u0026thinsp;15 kg, with a BMI of 36.02\u0026thinsp;\u0026plusmn;\u0026thinsp;5.2 kg/m\u0026sup2;.\u003c/p\u003e\u003cp\u003eRegarding the APC treatment, 11 patients (30.6%) required 1\u0026ndash;2 sessions, while 25 patients (69.4%) underwent 3\u0026ndash;4 sessions. No patient received more than four APC sessions.\u003c/p\u003e\u003cp\u003eAdverse events (AEs) occurred in three patients (8%): two cases of GJA stenosis and one case of GJA ulceration. All AEs were classified as mild. Both cases of stenosis were successfully managed with endoscopic dilation, while the ulceration resolved without the need for endoscopic intervention.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eDemographic and anthropometric profile of patients submitted to GJA reduction with APC. \u003cem\u003eBMI: Body mass index. OSAS: Obstructive sleep apnea syndrome. EBD: Eating behaviour disorder.\u003c/em\u003e\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eQuantitative variables\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAnthropometric profile\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHeight (m)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.64\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePre-surgery weight (kg)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e122.68\u0026thinsp;\u0026plusmn;\u0026thinsp;13\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePre-surgery BMI (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e45.51\u0026thinsp;\u0026plusmn;\u0026thinsp;4.49\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNadir BMI (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e29.83\u0026thinsp;\u0026plusmn;\u0026thinsp;3.5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePre-APC BMI (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e36.02\u0026thinsp;\u0026plusmn;\u0026thinsp;5.2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDemographic variables\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e43.95\u0026thinsp;\u0026plusmn;\u0026thinsp;10\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eQualitative variables\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eN (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSex\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWomen (n/%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e28 (77,8)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMen (n/%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e8 (22.2)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePatient comorbidities\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAny\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e19 (52.7)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eType 2 Diabetes mellitus (DM)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5 (13.9)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHypertension\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7 (19.4)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDyslipidemia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5 (13.9)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOSAS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e9 (25)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eEBD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5 (13.9)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003e3.2. Gastrojejunal anastomosis (GJA) diameter\u003c/h2\u003e\u003cp\u003eThe mean GJA diameter before the procedure was 26.6\u0026thinsp;\u0026plusmn;\u0026thinsp;5.4 mm, decreasing to an average of 16.4\u0026thinsp;\u0026plusmn;\u0026thinsp;5.0 mm (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). A total of 72% (n\u0026thinsp;=\u0026thinsp;26) of patients achieved a small final GJA diameter of \u0026lt;\u0026thinsp;18 mm. The absolute reduction in anastomosis diameter (RAD) was 10.22\u0026thinsp;\u0026plusmn;\u0026thinsp;6.39 mm, corresponding to a 36.9\u0026thinsp;\u0026plusmn;\u0026thinsp;19.3% reduction.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\u003ch2\u003e3.3. Total weight loss (TWL).\u003c/h2\u003e\u003cp\u003eTWL was assessed at three time points: short-term (3 months), mid-term (6 months), and long-term (12 months). The mean absolute TWL (%) was 8.3\u0026thinsp;\u0026plusmn;\u0026thinsp;7.1% at 3 months, 8.0\u0026thinsp;\u0026plusmn;\u0026thinsp;6.6% at 6 months, and 8.2\u0026thinsp;\u0026plusmn;\u0026thinsp;8.6% at 12 months. BMI (kg/m2) declined from 36.02\u0026thinsp;\u0026plusmn;\u0026thinsp;5.2 pre-APC to 32.91\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7 at 12 month (p\u0026thinsp;\u0026lt;\u0026thinsp;0.01).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eAdditionally, TWL was analyzed categorically using predefined thresholds (\u0026ge;\u0026thinsp;5%, \u0026ge;\u0026thinsp;10%, and \u0026ge;\u0026thinsp;15%) at all time points (Fig.\u0026nbsp;1). More than 60% of patients achieved at least 5% TWL across all follow-up periods. The proportion of patients achieving\u0026thinsp;\u0026ge;\u0026thinsp;10% TWL was lower, with 33.3% at 3 months, 33.3% at 6 months, and 38.9% at 12 months. A smaller subset of patients achieved\u0026thinsp;\u0026ge;\u0026thinsp;15% TWL: 19.4% at 3 months, 13.9% at 6 months, and 16.7% at 12 months.\u003c/p\u003e\u003cp\u003eAbsolute TWL was compared across all predefined categories (\u0026ge;\u0026thinsp;5%, \u0026ge;\u0026thinsp;10%, and \u0026ge;\u0026thinsp;15%) at short-term (3 months), mid-term (6 months), and long-term (12 months) follow-up using the McNemar test. No statistically significant differences were observed between the groups.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\u003ch2\u003e3.4. Possible variables associated with TWL\u003c/h2\u003e\u003cp\u003eThe study aimed to identify variables associated with greater absolute TWL. As the most significant weight loss was observed in the short-term period, analyses were focused on this time point. Absolute TWL at 3 months was compared across different patient comorbidities, demographic characteristics, and anthropometric profiles.\u003c/p\u003e\u003cp\u003eThe potential influence of the number of APC sessions on TWL was also evaluated by dividing patients into two groups: Patients who underwent 1\u0026ndash;2 sessions and patients who underwent 3\u0026ndash;4 sessions. Quantitative variables were correlated with TWL at 3 months using Spearman\u0026rsquo;s Rho test, revealing a weak correlation (ρ\u0026thinsp;=\u0026thinsp;0.163).\u003c/p\u003e\u003cp\u003eFor qualitative variables, comparisons were conducted using the Mann-Whitney U test. No significant differences were found in TWL among patients with the following comorbidities: hypertension, diabetes, dyslipidemia, obstructive sleep apnea, and eating disorders. Additionally, no association was found between the number of APC sessions and TWL at any follow-up period.\u003c/p\u003e\u003cp\u003eStatistical analyses of the variables were performed using Spearman\u0026rsquo;s Rho and the Mann-Whitney U test, as detailed in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eRelation between different variables and absolute TWL at 3 months.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3m TWL\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003eQuantitative variables. Spearmans\u0026rsquo; Rho test\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e% RAD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eRho value\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.163\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBasal BMI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eRho value\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.27\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eRho value\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.152\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eQualitative variables. U- Mann-Whitney test\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSex (f/m)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.819\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eComorbidities (y/n)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.558\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDM\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.262\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHypertension\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.105\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDyslipemia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.697\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOSAS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.674\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eEBD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.567\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eN\u0026ordf; APC (1\u0026ndash;2 / 3\u0026ndash;4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.986\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cem\u003eRAD: Reduction in Anastomosis Diameter. BMI: Body Mass Index. DM: Diabetes melitus. OSAS: Obstructive Sleep Apnea Syndrome. EBD: Eating behaviour Disorder. SD: Standard Deviation.\u003c/em\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003e3.5. APC-responders and possible associated factors,\u003c/h2\u003e\u003cp\u003eIn the short term (3 months), 22 patients (61%) achieved a\u0026thinsp;\u0026ge;\u0026thinsp;5% total weight loss (TWL) and were classified as \u0026lsquo;responders\u0026rsquo; to the APC procedure. In contrast, 14 patients (39%) experienced\u0026thinsp;\u0026lt;\u0026thinsp;5% TWL and were considered \u0026lsquo;non-responders.\u0026rsquo; Unlike non-responders, the responder group demonstrated sustained weight loss at both medium- and long-term follow-up.\u003c/p\u003e\u003cp\u003eMaximum weight loss was observed between 3 and 6 months following APC. Responders achieved a TWL of nearly 15%, whereas non-responders reached a maximum of 5.4%. These outcomes are illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eTWL at 12 months was analyzed in both groups. Among responders, more than 80% of patients maintained a weight loss of \u0026ge;\u0026thinsp;5% of total body weight, and over 50% achieved a TWL of \u0026ge;\u0026thinsp;10%. In contrast, only one-third of non-responders attained a TWL of \u0026ge;\u0026thinsp;5%. These results are illustrated in \u003cb\u003eFig.\u0026nbsp;3\u003c/b\u003e.\u003c/p\u003e\u003cp\u003eAt 12 months, the mean BMI in non-responders was 34.8\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1, whereas in responders, it was 31.7\u0026thinsp;\u0026plusmn;\u0026thinsp;4.1 with statistical differences (p\u0026thinsp;=\u0026thinsp;0.049). Notably, over a quarter (27.3%) of responders achieved a final BMI of less than 30, which may be considered a significant clinical success.\u003c/p\u003e\u003cp\u003eTo identify predictive factors associated with response to the APC procedure, various variables were analyzed between both groups. Mean values were calculated for most variables, except for the reduction in GJA diameter, where median values along with the interquartile range (25th and 75th percentiles) are reported. The P-value was determined using the Chi-square test (or Fisher\u0026rsquo;s exact test) and the Student's t-test; however, no statistically significant differences were observed. The results are presented in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eVariables in the responder and non-responder group. All values correspond with mean value\u0026thinsp;\u0026plusmn;\u0026thinsp;SD, except reduction in GJA diameter (median value is shown with interquartile 25th \u0026minus;\u0026thinsp;75th range). \u003cem\u003eBMI: Body Mass Index. APC: Argon Plasma Coagulation\u003c/em\u003e. \u003cem\u003eRAD: Reduction in anastomosis diameter. GJA: Gastroyeyunal anastomosis. RYGB: Roux-en-Y Gastric Bypass, TWL: Total weight loss. IQR\u003c/em\u003e: interquartile range.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eCategory\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNon-responders: Patients with TWL\u0026thinsp;\u0026lt;\u0026thinsp;5% at 3m\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eResponders: Patients with TWL\u0026thinsp;\u0026ge;\u0026thinsp;5% at 3m\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003ep value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e14\u003c/b\u003e/36 (\u003cb\u003e39%\u003c/b\u003e)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cb\u003e22\u003c/b\u003e/36 (\u003cb\u003e61%\u003c/b\u003e)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDemographic variables\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSex: Female\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11/14 (78.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e17/22 (77.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e0.631\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSex: Male\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3/14 (21.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5/22 (22.7%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge (years)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e44.8\u0026thinsp;\u0026plusmn;\u0026thinsp;12.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e43.4\u0026thinsp;\u0026plusmn;\u0026thinsp;8.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.768\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWeight\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI before RYGB (kg/m2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e44.5\u0026thinsp;\u0026plusmn;\u0026thinsp;5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e46.2\u0026thinsp;\u0026plusmn;\u0026thinsp;4.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.270\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI NADIR post-RYGB (kg/m2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e28.4\u0026thinsp;\u0026plusmn;\u0026thinsp;4.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e27.8\u0026thinsp;\u0026plusmn;\u0026thinsp;2.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.654\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI before APC (kg/m2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e36.3\u0026thinsp;\u0026plusmn;\u0026thinsp;5.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e35.9\u0026thinsp;\u0026plusmn;\u0026thinsp;5.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.824\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI 1 year post-APC (kg/m2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e34.8\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e31.7\u0026thinsp;\u0026plusmn;\u0026thinsp;4.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e0.049\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWeight regain after RYGB (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e22.5\u0026thinsp;\u0026plusmn;\u0026thinsp;11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e21.4\u0026thinsp;\u0026plusmn;\u0026thinsp;9.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.761\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI (kg/m2) 3 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e35.8\u0026thinsp;\u0026plusmn;\u0026thinsp;5.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e31.3\u0026thinsp;\u0026plusmn;\u0026thinsp;5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e0.015\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI (kg/m2) 6 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e34.6\u0026thinsp;\u0026plusmn;\u0026thinsp;5.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e32.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.263\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI (kg/m2) 12 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e34.8\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e31.7\u0026thinsp;\u0026plusmn;\u0026thinsp;4.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.092\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"4\" nameend=\"c4\" namest=\"c1\"\u003e\u003cp\u003eProcedure and GJA diameter\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNumber of APC procedures (median)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.557\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBaseline GJA diameter (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e26.5\u0026thinsp;\u0026plusmn;\u0026thinsp;5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e26.7\u0026thinsp;\u0026plusmn;\u0026thinsp;5.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.923\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFinal GJA diameter (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e15.8\u0026thinsp;\u0026plusmn;\u0026thinsp;4.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e16.8\u0026thinsp;\u0026plusmn;\u0026thinsp;5.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.577\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSmall final GJA (\u0026lt;\u0026thinsp;18mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11/14 (78.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e15/22 (68.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.706\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRAD (mm) median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-10 (-14.3,-5.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-10 (-14.3, -4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.896\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRAD (%) median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-39.3 (-50,-23)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-33.8 (-54.3, -19.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.808\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"4. DISCUSSION","content":"\u003cp\u003eThis retrospective study highlights the efficacy of APC, demonstrating significant TWL at all time points in patients who experienced weight regain following RYGB.\u003c/p\u003e\u003cp\u003eInitially, all patients experienced some degree of weight loss after the APC intervention. However, when grouped by TWL, weight regain appears to be a common trend among the majority of patients, with only 13.9% and 16.7% maintaining a TWL of \u0026ge;\u0026thinsp;15% at the medium and long-term follow-ups, respectively. This underscores the chronic nature of obesity, with weight regain being influenced by various behavioural factors. It also suggests that the effects of APC may be inconsistent over the long term.\u003c/p\u003e\u003cp\u003eNonetheless, our results regarding TWL are noteworthy, with a loss of 7.96% (\u0026plusmn;\u0026thinsp;6.57) at 6 months. This is consistent with other studies, such as that of Moon et al. (13), who analysed 588 patients undergoing APC in bariatric centres and reported a %TWL of 6.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.3 at 6 months.\u003c/p\u003e\u003cp\u003eA clear distinction in APC response between responders and non-responders was evident as early as 3 months, leading to the classification of patients as \u0026lsquo;responders\u0026rsquo; (\u0026ge;\u0026thinsp;5% TWL) and \u0026lsquo;non-responders\u0026rsquo; (\u0026lt;\u0026thinsp;5% TWL). At 3 months, responders achieved a total weight loss nearly 10 times greater than that of non-responders. By 6 months, responders still maintained twice the TWL compared to non-responders.\u003c/p\u003e\u003cp\u003eIn our analysis, we were unable to identify any specific clinical or endoscopic variables\u0026mdash;such as baseline anastomosis diameter, GJA diameter reduction, or early response to therapy\u0026mdash;that could reliably predict the degree of success following APC treatment. This suggests that the variability in weight loss outcomes may not be solely attributable to anatomical or procedural factors. One important consideration is that, while all patients were provided with standardized nutritional guidelines following the intervention, adherence to these recommendations was not systematically assessed. It is therefore possible that differences in patient compliance with dietary instructions may have contributed to the heterogeneity in long-term outcomes. This limitation highlights the need for improved strategies to monitor and support post-procedural behavioral adherence in future studies.\u003c/p\u003e\u003cp\u003eEarly weight loss at 3 months\u0026mdash;specifically a TWL\u0026thinsp;\u0026ge;\u0026thinsp;5%\u0026mdash;appears to be a reliable predictor of greater long-term weight reduction. This finding suggests that early response to APC may serve as a useful clinical marker to stratify patients based on expected treatment benefit. Conversely, for those classified as non-responders at 3 months, it may not be necessary to prolong observation before considering alternative therapeutic strategies. In such cases, timely initiation of adjunctive treatments, including pharmacologic therapy or endoscopic options such as endoscopic suturing (TORe) (14), could be more effective in optimizing outcomes and preventing further weight regain.\u003c/p\u003e\u003cp\u003eRegarding the mean BMI at 12-month follow-up, over a quarter (27.3%) of responders achieved a final BMI of less than 30, which could be considered a significant success, as these patients were no longer classified as obese.\u003c/p\u003e\u003cp\u003eMoreover, no significant differences were found in demographics, weight loss, or GJA diameter between the two groups. This is likely due to the relatively small number of patients included in the study. In these groups, factors such as age, BMI before the procedure, and the size of the anastomosis at the end of the APC were not associated with greater weight loss. While significant lifestyle changes may have contributed to greater weight loss after APC, the recording of nutritional and physical activity data during follow-up did not reveal any significant differences between the two response groups. A prospective study comparing various endoscopic bariatric procedures suggested that multidisciplinary team (MDT) follow-up plays a more crucial role in weight loss than the specific type of endoscopic procedure itself (15).\u003c/p\u003e\u003cp\u003eRegarding patients' comorbidities and their relationship with TWL, the reduced sample size was a significant limitation. Only five patients were included for each of the following comorbidities: diabetes mellitus (DM), dyslipidemia, and esophageal bowel dysmotility (EBD). Additionally, only nine patients had OSA. In contrast, hypertension was a prevalent comorbidity, observed in 29 (80.5%) patients.\u003c/p\u003e\u003cp\u003eIn conclusion, no clinically significant associations were found between any pre-treatment factors and subsequent weight loss. This includes demographic data, BMI evolution, comorbidities, or the anatomical changes of the gastrojejunal anastomosis following the APC procedure.\u003c/p\u003e\u003cp\u003eOn the other hand, it has been demonstrated (16) that a higher power APC setting is associated with a deeper tissue effect. Specifically, a high dose (considered as 70-80W) has been shown to be superior to a low dose (45-55W) in the treatment of weight regain (16). In this study, all patients received a high dose of 80W. However, other variables, such as the duration of APC and the distance between the probe and the tissue, may also contribute to this effect; although these factors cannot be accurately monitored.\u003c/p\u003e\u003cp\u003eAccording to the literature (17,18), TWL appears to be a consequence of GJA reduction. When analysing GJA reduction, the raw results are considerable: the GJA size was reduced by a third (%RAD 36.86%), which corresponds to a 10mm reduction. Patients had a dilated GJA, with a mean pre-APC GJA diameter of 26.61\u0026thinsp;\u0026plusmn;\u0026thinsp;5.41mm. Contrary to expectations, neither the RAD nor the GJA diameter were found to be predictors of TWL. Jirapinyo et al. (16) suggested that patients with larger GJA diameters (defined as \u0026gt;\u0026thinsp;18mm) may respond better to alternative endoscopic therapies, such as endoscopic suturing (TORe), rather than APC.\u003c/p\u003e\u003cp\u003eDespite the lack of a statistical association between TWL, GJA diameter, or RAD, 72% of patients achieved a smaller GJA (\u0026le;\u0026thinsp;18mm), and nearly 60% experienced a\u0026thinsp;\u0026ge;\u0026thinsp;5% weight loss in the short term, as previously mentioned. Due to the limited number of subjects in our study, we were unable to perform a multivariate analysis to determine the strength of this relationship. However, this could be explored further in future studies.\u003c/p\u003e\u003cp\u003eFurthermore, the number of APC sessions has been statistically associated with TWL in other studies (16). In our study, however, we found no statistical difference between the number of APC sessions and TWL. We hypothesize that individual factors, likely related to the patient's lifestyle and behavioural habits, may play a significant role in weight loss. While this aspect was not evaluated in our study, it could be explored in future research.\u003c/p\u003e\u003cp\u003eOur results demonstrate that APC treatment for weight regain is a safe technique. The rate of adverse events was 8%, which aligns with the 3% reported in Moon et al.'s study (13). Additionally, no serious complications, such as bleeding or perforation, were observed. This is likely due to the superficial effect of APC which typically results in tissue penetration of 1 to 3mm (17).\u003c/p\u003e\u003cp\u003eThe study does have some limitations. Primarily, as a single centre study, the sample size is small, which accounts for the lack of significant associations between demographic factors, BMI, comorbidities, and TWL. However, our study has demonstrated that a simple, non-invasive method such as endoscopic APC therapy can be effective in reversing weight regain after RYGB in more than half of the patients.\u003c/p\u003e\u003cp\u003eIn conclusion, APC therapy for GJA reduction is a safe and effective treatment for weight regain, at least in the short and medium term, in 60% of patients. It is recommended that prospective studies with larger patient cohorts are conducted, incorporating additional variables associated with lifestyle changes following APC.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eC. Rodriguez Carrillo and S. Mera Carreiro wrote the main manuscript text. R. S\u0026aacute;nchez Del Hoyo has performed all the statistical analysesM.A. Rubio Herrera is the main reviewer of the article, although all authors have contributed to its revision.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eMagro DO, Geloneze B, Delfini R, Pareja BC, Callejas F, Pareja JC. Long-term weight regain after gastric bypass: a 5-year prospective study. Obes Surg. 2008;18(6):648-51.\u003c/li\u003e\n\u003cli\u003eAdams TD, Davidson LE, Litwin SE, Kim J, Kolotkin RL, Nanjee MN. Weight and Metabolic Outcomes 12 Years after Gastric Bypass. N Engl J Med. 2017;377:1143-55.\u003c/li\u003e\n\u003cli\u003eKarmali S, Brar B, Shi X, Sharma AM, Gara C de, Birch DW. Weight recidivism post-bariatric surgery: A systematic review. Obes Surg. 2013;23(11):1922-33.\u003c/li\u003e\n\u003cli\u003eHenegham HM, Yimcharoen P, Brethauer SA. Influence of pouch size and stoma size on weight loss after gastric bypass. Surg Obes Relat Dis. 2012;8(4):408-15.\u003c/li\u003e\n\u003cli\u003eHandi A, Julien C, Brown P. Midterm outcomes of revisional surgery for gastric pouch and gastrojejunal anastomotic enlargement in patients with weight regain after gastric bypass for morbid obesity. Obes Surg. 2014;24(8):1386-90.\u003c/li\u003e\n\u003cli\u003eYimcharoen P, Heneghan HM, Singh M, Brethauer S, Schauer P, Rogula T. Endoscopic findings and outcomes of revisional procedures for patients with weight recidivism after gastric bypass. Surg Endosc. 2011;25(10):3345-52.\u003c/li\u003e\n\u003cli\u003eSpaulding L, Osler T, Patlak J. Long-term results of sclerotherapy for dilated gastrojejunostomy after gastric bypass. Surg Obes Relat Dis. 2007;3(6):623-6.\u003c/li\u003e\n\u003cli\u003eThompson CC, Slattery J, Bundga ME. Peroral endoscopic reduction of dilated gastrojejunal anastomosis after Roux-en-Y gastric bypass: a possible new option for patients with weight regain. Surg Endosc. 2006;20(11):1744-8.\u003c/li\u003e\n\u003cli\u003eMikami D, Needleman B, Narula V. Natural orifice surgery: initial US experience utilizing the StomaphyX device to reduce gastric pouches after Roux-en-Y gastric bypass. Surg Endosc. 2010;24(1):223-8.\u003c/li\u003e\n\u003cli\u003eThompson CC, Jacobsen GR, Schroder GL. Stoma size critical to 12-month outcomes in endoscopic suturing for gastric bypass repair. Surg Obes Relat Dis. 2012;8(3):282-7.\u003c/li\u003e\n\u003cli\u003eHeylen AM, Jacobs A, Lybeer M. The OTSC(R)-clip in revisional endoscopy against weight gain after bariatric gastric bypass surgery. Obes Surg. 2011;21(10):1629-33.\u003c/li\u003e\n\u003cli\u003eBaretta GA, Alhinho HC, Matias JE. Argon plasma coagulation of gastrojejunal anastomosis for weight regain after gastric bypass. Obes Surg. 2015;25(1):72-9.\u003c/li\u003e\n\u003cli\u003eMoon, R.C., Texeira, A.F, Neto, M.G. Efficacy of Utilizing Argon Plasma Coagulation for Weight Regain in Roux-en-Y Gastric Bypass Patients: a Multi-center Study. 2018;28(9):2737-44.\u003c/li\u003e\n\u003cli\u003eSzvarca D, Jirapinyo P. Endoscopic Management of Weight Regain After Bariatric Surgery. Gastrointest Endosc Clin N Am. 2024;34(4):639-54.\u003c/li\u003e\n\u003cli\u003eLopez-Nava G, Asokkumar R, Rull A, Corbelle F, Beltran L, Bautista I. Bariatric endoscopy procedure type or follow-up: What predicted success at 1 year in 962 obese patients? Endosc Int Open. 2019;07(12):E1691-8.\u003c/li\u003e\n\u003cli\u003eJirapinyo, P, Moura D, Dong W. Dose response for argon plasma coagulation in the treatment of weight regain after Roux-en-Y gastric bypass. Gastrointest Endosc. 2020;91(5):1078-84.\u003c/li\u003e\n\u003cli\u003eFlanagan L. Measurement of functional pouch volume following the gastric bypass procedure. Obes Surg. 1996;6(1):38-43.\u003c/li\u003e\n\u003cli\u003eM\u0026uuml;ller MK, Wildi S, Scholz T. Laparoscopic pouch resizing and redo of gastro-jejunal anastomosis for pouch dilatation following gastric bypass. Obes Surg. 2005;15(8):1089-95.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"obesity surgery, Roux-en-Y gastric bypass, weight regain, argon plasma coagulation","lastPublishedDoi":"10.21203/rs.3.rs-6956733/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6956733/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBACKGROUND \u0026amp; AIMS\u003c/p\u003e\n\u003cp\u003eArgon plasma coagulation (APC) is effective in the reduction of gastrojejunal anastomosis (GJA) for weight regain after Roux-en-Y gastric bypass (RYGB). This study aims to confirm the efficacy of APC in treating weight regain following RYGB surgery and to analyse factors associated with treatment success.\u003c/p\u003e\n\u003cp\u003ePATIENTS AND METHODS\u003c/p\u003e\n\u003cp\u003eSingle-center retrospective study of 36 RYGB patients who underwent APC for weight regain from 2018 to 2023.\u003c/p\u003e\n\u003cp\u003ePercentage total weight loss (%TWL) was analyzed as the primary outcome and reduction in anastomosis diameter (RAD), comorbidities, and adverse events (AE) were evaluated as secondary outcomes. Patients were classified according to %TWL categories of ≥5%, ≥10% or ≥15% and were followed up at 3, 6 and 12 months. Patients with ≥5% TWL at 3 months were considered responders. The relationship between %TWL and age, sex, changes in BMI and comorbidities was analyzed.\u003c/p\u003e\n\u003cp\u003eRESULTS\u003c/p\u003e\n\u003cp\u003eOver 60% of patients lost ≥5% TWL at 3, 6 and 12 months, with no statistical association with RAD. TWL for responders was 14,9%, 11,7% and 11,1% at 3, 6, 12 months respectively with statistical differences compared to non-responders. No clinically significant associations were found between pre-treatment factors and subsequent weight loss. At 12 months, over 80% of patients maintained ≥5% of TWL, and over half achieved a TWL of ≥10%. Mean BMI in responders was 31.68 ± 0.1; and over a quarter (27.3%) of them achieved a final BMI of less than 30, which could be considered a significant success, as these patients would no longer be classifed as obese. Technical success was 100%. Only 3(8%) AEs were registered, withmild anastomotic stenosis occuring most commonly.\u003c/p\u003e\n\u003cp\u003eCONCLUSIONS:\u003c/p\u003e\n\u003cp\u003eAPC is a simple and effective technique for inducing weight loss after RYGB, with beneficial results observed in at least 60% of patients in this study.\u003c/p\u003e","manuscriptTitle":"Efficacy of argon plasma coagulation (APC) in the reduction of gastrojejunal anastomosis for weight regain after Roux-en-Y gastric bypass","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-14 08:57:57","doi":"10.21203/rs.3.rs-6956733/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"d0920585-c2b4-42dd-aea5-284bcbc17d2e","owner":[],"postedDate":"July 14th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-07-15T12:09:03+00:00","versionOfRecord":[],"versionCreatedAt":"2025-07-14 08:57:57","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6956733","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6956733","identity":"rs-6956733","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}