Tony Boutros

Background: Obesity is associated with increased complications after solid organ transplantation (SOT). While metabolic and bariatric surgery (MBS) improves survival, metabolic, and graft outcomes in transplant patients, we aim to clarify the risk that duodenal bypass MBS (DB-MBS) has on immunosuppression and acute rejection. Methods: A single-center retrospective cohort study was conducted on patients who underwent SOT and DB-MBS between 2003 and 2025. Immunosuppressant regimens and biopsy-confirmed acute rejection details were collected for 3 years after each procedure. Immunosuppressant dosing and trough levels were normalized to individual target levels and evaluated with linear-mixed effects models. Results: The cohort included 19 patients. There were no statistically significant differences in immunosuppression outcomes when DB-MBS is performed before (dosing P =0.821, trough P =0.916) and after (dosing P =0.368, trough P =0.317) SOT. The 3-year acute rejection incidence was 21.1%. Conclusion: The presence and timing of DB-MBS did not significantly alter immunosuppression dosing and trough levels.

Introduction Metabolic and bariatric surgery (MBS) provides high rates of remission of obesity-related medical conditions (ORMC). However, recurrence of previously resolved ORMC remains an important concern. There is limited data on predictors of obesity-related medical conditions recurrence (ORMCR). Methods A retrospective study was conducted of patients undergoing primary sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), or duodenal switch (DS) between 2008 and 2022. Patients with ≥ 36 months of follow-up, ≥ 20% total weight loss, and initial remission of type 2 diabetes mellitus (T2D), hypertension (HTN), hyperlipidemia (HLD), or obstructive sleep apnea (OSA) were included. ORMC resolution and recurrence were defined using prespecified criteria. Recurrent weight gain (RWG) was categorized as no RWG (≤ 20%), moderate RWG (> 20%-≤50%), and severe RWG (> 50%). Separate multivariable Cox regression models were constructed for each ORMCR outcome. Results Among 1,323 patients with remission of at least one ORMC, ORMCR occurred in 76 (16.2%) patients with T2D, 117 (21.3%) with HTN, 71 (19.0%) with HLD, and 40 (5.4%) with OSA. Severe RWG was independently associated with increased HLD recurrence. RYGB and DS were associated with lower risks of T2D and HLD recurrence compared with SG, whereas T2D and HTN recurrence were driven by insulin dependence and higher HbA1c for T2D, and greater antihypertensive medication burden and older age for HTN. White race was protective against HTN recurrence. Conclusions The metabolic benefits of MBS remained largely durable, with ORMCR driven more strongly by baseline disease severity and patient-specific factors than by RWG itself.

Background Marginal ulcers (MU) represent a common and serious complication following Roux-en-Y gastric bypass (RYGB). While most MUs heal with conservative therapy, a subset requires endoscopic or surgical intervention. This study aims to characterize management trajectories and identify predictors of perforation. Methods A retrospective review was performed to identify patients who underwent RYGB between 2008 and 2023 at a tertiary referral center and were subsequently diagnosed with MU. Baseline characteristics, management strategies, and clinical outcomes were collected. MU management was categorized as medical, endoscopic, or surgical. Continuous variables were summarized using medians with interquartile ranges (IQR), and categorical variables using frequencies and percentages. Univariate testing, multivariate regression, and time-to-event analyses were used to assess predictors of MU perforation. Results Among 2106 patients, 241 patients developed MUs (incidence 11.4%). Ulcers were identified at a median of 7.1 months (IQR 3.0–16.2) following RYGB. Most patients (77.2%) resolved with medical management, while 22.8% required escalation to endoscopic (11.2%) or surgical (11.6%) intervention. The median time from MU diagnosis to surgical intervention was 12.1 months (IQR 4.9–21.2) after excluding patients who presented with perforation at the time of MU diagnosis. Ulcer perforation occurred in 24 patients and was managed with Graham patch repair or endoscopic techniques. Multivariate analysis showed that female sex (OR 0.31; 95% CI 0.11–0.85; p = 0.035) was associated with a decreased risk of perforation, while smoking resumption at 6 months postoperatively (OR 4.46; 95% CI 1.24–16.08; p 0.025) was associated with an increased risk. Univariate analysis also demonstrated that hand-sewn anastomosis was associated with significantly higher risk of MU perforation compared with linear stapling (OR 4.25, 95% CI 1.70-10.69; p = 0.002). Conclusion Although most MUs respond to medical therapy, nearly one-quarter of patients require endoscopic or surgical intervention. Resumption of smoking after surgery and male sex are independently associated with perforation. These findings support early recognition of refractory disease, risk-factor modification, and timely escalation of care.

Background and Objectives: Roux-en-Y gastric bypass (RYGB) is one of the most commonly performed metabolic and bariatric surgeries worldwide. Marginal ulcers (MU) are a common complication following RYGB, yet their pathophysiology and the contributing risk factors to their development are not fully understood. Materials and Methods: This retrospective cohort study examined patients who underwent RYGB between January 2008 and December 2023, with 1 to 5 years of follow-up. Data collected included patient- and procedure-related risk factors, as well as postoperative MU events. Statistical analysis methods included the independent samples t-tests, multivariate regression, and Cox regression analyses. Results: Our final cohort included 2106 patients and was predominantly female (80.5%), with a mean age of 47.8 ± 12.1 years and body mass index (BMI) of 45.5 ± 7.5 kg/m². MU occurred in 241 (11.4%) patients, with a mean time to occurrence of 4.5 ± 0.02 years. History of smoking (HR = 1.87, p < 0.001) and gastroesophageal reflux disease (HR = 2.36, p < 0.001) significantly increased hazard for MU, while proton pump inhibitor use (HR = 0.18, p < 0.001) was associated with reduced hazard. Aspirin exposure, regardless of dose and chronicity, did not impact MU. Conclusions: Our findings highlight the importance of preoperative assessment and counseling in patients planning to undergo RYGB. Patient-related factors should guide postoperative monitoring and prophylaxis of MU, as this remains a debated topic amongst experts.