The number of obese individuals worldwide continues to increase every year, thus, the number of bariatric/metabolic operations performed is on a constant rise as well. Beside exclusively restrictive procedures, most of the bariatric operations have a more or less malabsorptive component. Several different bypass procedures exist alongside each other today and each type of bypass is performed using a distinct technique. Furthermore, the length of the bypassed intestine may differ as well. One might add that the operations are performed differently in different parts of the world and have been changing and evolving over time. This review evaluates the most frequently performed bariatric bypass procedures (and their variations) worldwide: Roux-en-Y Gastric Bypass, One-Anastomosis Gastric Bypass, Single-Anastomosis Duodeno-Ileal Bypass + Sleeve Gastrectomy, Biliopancreatic Diversion + Duodenal Switch and operations due to weight regain. The evaluation of the procedures and different limb lengths focusses on weight loss, remission of comorbidities and the risk of malnutrition and deficiencies. This narrative review does not aim at synthesizing quantitative data. Rather, it provides a summary of carefully selected, high-quality studies to serve as examples and to draw tentative conclusions on the effects of the bypass procedures mentioned above. In conclusion, it is important to carefully choose the procedure and small bowel length excluded from the food passage suited best to each individual patient. A balance has to be achieved between sufficient weight loss and remission of comorbidities, as well as a low risk of deficiencies and malnutrition. In any case, at least 300 cm of small bowel should always remain in the food stream to prevent the development of deficiencies and malnutrition.

Interleukin-6 (IL-6) can cause pro- and anti-inflammatory effects via different signaling pathways. This prospective study investigated the perioperative kinetics of IL-6, soluble IL-6 receptor (sIL-6R), and soluble glycoprotein 130 (sgp130) in elective patients undergoing cardiopulmonary bypass (CPB). IL-6, sIL-6R, and sgp130 were measured simultaneously and consecutively at 19 timepoints until the 10th postoperative day (POD). The proportion of pro- and anti-inflammatory pathways were determined by calculating sIL-6R/IL-6 and sIL-6R/sgp130 ratios. We analyzed 93 patients. IL-6 increased during surgery with reaching a plateau two hours after CPB and peaking on POD 1 (188.5 pg mL⁻¹ (IQR, 126.6; 309.2)). sIL-6R decreased at the beginning of the surgical procedure, reaching a nadir level on POD 2 (26,311 pg mL⁻¹ (IQR, 22,222; 33,606)). sgp130 dropped immediately after CPB initiation (0.13 ng mL⁻¹ (IQR, 0.12; 0.15)), followed by a continuous recovery until POD10. The sIL-6R/IL-6 ratio decreased substantially at the beginning of the procedure, reaching a nadir on POD 1 (149.7 (IQR, 82.4; 237.4)), while the sIL-6R/sgp130 ratio increased simultaneously until 6 h post CPB (0.219 (IQR 0.18; 0.27)). In conclusion, IL-6 exhibited high inter-individual variability reflecting an inhomogeneous inflammatory response. Pro-inflammatory effects and overwhelming inflammation were rare and predominantly anti-inflammatory effects were found.

Background: The phase angle (PhA) can be used for prognostic assessments in critically ill patients. This study describes the perioperative course of PhA and associated risk indicators in a cohort of elective cardiac surgical patients. Methods: The PhA was measured in 168 patients once daily until postoperative day (POD) seven. Patients were split into two groups depending on their median preoperative PhA and analyzed for several clinical outcomes; logistic regression models were used. Results: The PhA decreased from preoperative (6.1° ± 1.9°) to a nadir on POD 2 (3.5° ± 2.5°, mean difference −2.6° (95% CI, −3.0°; −2.1°; p < 0.0001)). Patients with lower preoperative PhA were older (71.0 ± 9.1 vs. 60.9 ± 12.0 years; p < 0.0001) and frailer (3.1 ± 1.3 vs. 2.3 ± 1.1; p < 0.0001), needed more fluids (8388 ± 3168 vs. 7417 ± 2459 mL, p = 0.0287), and stayed longer in the ICU (3.7 ± 4.5 vs. 2.6 ± 3.8 days, p = 0.0182). Preoperative PhA was independently influenced by frailty (OR 0.77; 95% CI 0.61; 0.98; p = 0.0344) and cardiac function (OR 1.85; 95%CI 1.07; 3.19; p = 0.028), whereas the postoperative PhA decline was independently influenced by higher fluid balances (OR 0.86; 95% CI 0.75; 0.99; p = 0.0371) and longer cardiopulmonary bypass times (OR 0.99; 95% CI 0.98; 0.99; p = 0.0344). Conclusion: Perioperative PhA measurement is an easy-to-use bedside method that may critically influence risk evaluation for the outcome of cardiac surgery patients.

Introduction: Overweight and obesity have been steadily increasing worldwide. Metabolic/bariatric surgery (MBS) is the most effective treatment for obesity and its associated medical conditions. Obesity complications increase with age, however, older patients face a higher perioperative risk necessitating a clear risk-benefit balance. This study evaluated weight-loss outcomes, remission of associated medical conditions, and complications in patients aged ≥ 65 years undergoing MBS. Methods: This retrospective analysis included patients aged ≥ 65 years who underwent MBS at the Medical University of Vienna between 2008 and 2025. Weight and associated medical complications were assessed at baseline and at 1, 2, and 5 years postoperatively. Early (< 30 days) and late complications up to 5 years were recorded. Results: In total, 111 patients were included. Baseline weight was 125.8 ± 22.3 kg and BMI 45.2 ± 7.4 kg/ $$\:{\text{m}}^{2}$$ . At 5 years, mean BMI decreased to 27.5 ± 6.2 kg/ $$\:{\text{m}}^{2}$$ corresponding to a total weight loss of 37.3 ± 14.7%. The prevalence of type II diabetes decreased from 54.1% to 22.9% and arterial hypertension from 87.4% to 56.2%. Early and late complications each occurred in 7.2%. Conclusion: MBS achieves substantial long-term weight reduction and remission of associated medical conditions. Complication rates are relatively high, underscoring careful patient selection is essential. Larger prospective studies focusing on elderly populations are warranted. Keypoints: MBS in elderly patients is effective in terms of weight loss and remission of associated medical complications. - MBS in elderly patients was associated with a relatively high complication rate. - Deaths within the study period were not associated with the MBS procedure.

Background: Swallowable intragastric balloons represent an evolving minimally invasive treatment option for obesity. The current first-in-human study evaluated the safety and efficiency of a novel swallowable self-expanding intragastric balloon (IGBalloon©) with a kidney-shaped design, intended to reduce the risk of migration. Setting: Single-center, prospective first-in-human study at a tertiary metabolic/bariatric center. Methods: This prospective open-label, non-randomized trial was designed to include 20 patients with obesity. Patients with a body mass index (BMI) >35 kg/m² or >30 kg/m² with at least one obesity-related complication were eligible. The primary endpoints were safety and efficacy, including weight loss and remission of obesity-related complications. Patients were allowed to ingest up to five balloons during follow-up. Results: Due to two severe adverse events (SAE), the trial was terminated prematurely after the inclusion of five patients. Two patients developed small bowel obstruction caused by balloon migration through the pylorus, requiring emergency laparoscopic enterotomy and balloon removal. Conclusion: This first-in-human study demonstrated a substantial risk of balloon migration and small bowel obstruction associated with the current kidney-shaped IGBalloon© design. The device in its present form is not qualified for clinical use.