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. 2025 Jan;39(1):459-464.
doi: 10.1007/s00464-024-11280-1. Epub 2024 Oct 6.

1- and 2-year outcomes and predictors of weight loss after gastric sleeve to Roux-en-Y gastric bypass conversion: a retrospective cohort study

Jayson S Marwaha #  1   2 , Miskir Belayneh #  3 , Grace C Bloomfield  3 , Narica Clarke  1   2 , Chaitanya Vadlamudi  1   4   5 , Ivanesa L Pardo Lameda  1   4 , Yewande R Alimi  6   7   8   9
Affiliations

1- and 2-year outcomes and predictors of weight loss after gastric sleeve to Roux-en-Y gastric bypass conversion: a retrospective cohort study

Jayson S Marwaha et al. Surg Endosc. 2025 Jan.

Abstract

Background: Sleeve gastrectomy to Roux-en-Y bypass conversion is a commonly performed procedure, yet data are limited on outcomes and their predictors. The purpose of this study is to characterize the long-term outcomes of patients after sleeve-to-bypass conversion and identify predictors of post-conversion outcomes.

Methods: We performed a retrospective cohort study of patients who underwent sleeve-to-bypass conversion for obesity across four hospitals from 06/2017 to 04/2023. Predictors of the below-average percent excess weight loss (%EWL; relative to pre-conversion weight) at 1 and 2 years following conversion were identified using multivariate logistic regression models adjusting for comorbidities, demographics, and neighborhood socioeconomic status.

Results: 150 Patients undergoing sleeve-to-bypass conversion were identified. 99 had 1-year data and 63 had 2-year data. Mean %EWL at 1- and 2-years following conversion were 40.2% and 37.4%, respectively. EWL > 40% after sleeve gastrectomy was an independent predictor of the below-average %EWL 1-year post-conversion (OR 10.0, 95% CI 2.2-63.0, p < 0.01), and BMI > 40 kg/m2 at the time of conversion was an independent predictor of both 1- and 2-year below-average %EWL post-conversion (p = 0.01 and 0.05, respectively). Insignificant predictors of the below-average %EWL after conversion included: weight regain after sleeve, time between sleeve and conversion, alimentary limb length, and any bariatric surgery prior to sleeve gastrectomy.

Conclusion: Patients should be counseled that the typical expected %EWL for sleeve-to-bypass conversion is less than the 50% EWL benchmark of success for index bariatric operations. The main predictors of a suboptimal conversion outcome are > 40% EWL after sleeve or > 40 BMI kg/m2 at the time of conversion. Most variables in our analysis were not predictors of post-conversion %EWL, including weight regain between sleeve and conversion, alimentary limb length, and time interval between procedures, which suggests that these factors should not play a large role when considering sleeve-to-bypass conversion.

Keywords: Gastric bypass; Revisional bariatric surgery; Sleeve gastrectomy.

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Conflict of interest statement

Declarations. Disclosures: Dr. Yewande Alimi reports consulting honoraria from Medtronic. Drs. Jayson Marwaha, Chaitanya Vadlamudi, Ivanesa Pardo, Narica Clarke, Ms. Grace Bloomfield, and Ms. Miskir Belayneh declare no competing interests or financial ties.

References

    1. Kheirvari M, Dadkhah Nikroo N, Jaafarinejad H, Farsimadan M, Eshghjoo S, Hosseini S, Anbara T (2020) The advantages and disadvantages of sleeve gastrectomy; clinical laboratory to bedside review. Heliyon 6:e03496. https://doi.org/10.1016/j.heliyon.2020.e03496 - DOI - PubMed - PMC
    1. Seeras K, Sankararaman S, Lopez PP (2024) Sleeve gastrectomy. In: StatPearls. StatPearls Publishing, Treasure Island
    1. Quezada N, Hernández J, Pérez G, Gabrielli M, Raddatz A, Crovari F (2016) Laparoscopic sleeve gastrectomy conversion to Roux-en-Y gastric bypass: experience in 50 patients after 1 to 3 years of follow-up. Surg Obes Relat Dis 12:1611–1615. https://doi.org/10.1016/j.soard.2016.05.025 - DOI - PubMed
    1. Matar R, Monzer N, Jaruvongvanich V, Abusaleh R, Vargas EJ, Maselli DB, Beran A, Kellogg T, Ghanem O, Abu Dayyeh BK (2021) Indications and outcomes of conversion of sleeve gastrectomy to Roux-en-Y gastric bypass: a systematic review and a meta-analysis. Obes Surg 31:3936–3946. https://doi.org/10.1007/s11695-021-05463-1 - DOI - PubMed
    1. Felsenreich DM, Langer FB, Kefurt R, Panhofer P, Schermann M, Beckerhinn P, Sperker C, Prager G (2016) Weight loss, weight regain, and conversions to Roux-en-Y gastric bypass: 10-year results of laparoscopic sleeve gastrectomy. Surg Obes Relat Dis 12:1655–1662. https://doi.org/10.1016/j.soard.2016.02.021 - DOI - PubMed