METHODS: A committee of 61 well-known metabolic and bariatric surgeons from 24 countries was created to participate in the Delphi consensus. The committee voted on 45 statements regarding recommendations and controversies around fasting after MBS. An agreement/disagreement ≥ of 70.0% was regarded as consensus.

RESULTS: The experts reached a consensus on 40 out of 45 statements after two rounds of voting. One hundred percent of the experts believed that fasting needs special nutritional support in patients who underwent MBS. The decision regarding fasting must be coordinated among the surgeon, the nutritionist and the patient. At any time after MBS, 96.7% advised stopping fasting in the presence of persistent symptoms of intolerance. Seventy percent of the experts recommended delaying fasting after MBS for 6 to 12 months after combined and malabsorptive procedures according to the patient's situation and surgeon's experience, and 90.1% felt that proton pump inhibitors should be continued in patients who start fasting less than 6 months after MBS. There was consensus that fasting may help in weight loss, improvement/remission of non-alcoholic fatty liver disease, dyslipidemia, hypertension and type 2 diabetes mellitus among 88.5%, 90.2%, 88.5%, 85.2% and 85.2% of experts, respectively.

METHODS: Eighty-nine recognized MBS surgeons from 42 countries participated in the Modified Delphi consensus to vote on 30 statements in two rounds. An agreement/disagreement among ≥ 70.0% of the experts was regarded to indicate a consensus.

RESULTS: Consensus was reached on 29 out of 30 statements. Most experts agreed that before getting privileges to perform MBS, surgeons must hold a general surgery degree and complete or have completed a dedicated fellowship training program. The experts agreed that the learning curves for the various operative procedures are approximately 25-50 operations for the LSG, 50-75 for the OAGB, and 75-100 for the RYGB. 93.1% of experts agreed that MBS surgeons should diligently record patients' data in their National or Global database.

METHOD: We performed an international study of adults (≥ 18 years) who underwent surgery for PPU from 1st January 2022 to 30th June 2022. Patients who were treated conservatively or had an underlying gastric cancer were excluded. Patients were divided into subgroups according to age (≤ 50 and > 50 years) and time from onset of symptoms to hospital presentation (≤ 24 and > 24 h). Univariate and Multivariate analyses were carried out to identify factors associated with higher 30-day morbidity and mortality.

RESULTS:  1874 patients from 159 centres across 52 countries were included. 78.3% (n = 1467) of the patients were males and the median (IQR) age was 49 years (25). Thirty-day morbidity and mortality were 48.5% (n = 910) and 9.3% (n = 174) respectively. Median (IQR) hospital stay was 7 (5) days. Open surgery was performed in 80% (n = 1505) of the cohort. Age > 50 years [(OR = 1.7, 95% CI 1.4-2), (OR = 4.7, 95% CI 3.1-7.6)], female gender [(OR = 1.8, 95% CI 1.4-2.3), (OR = 1.9, 95% CI 1.3-2.9)], shock on admission [(OR = 2.1, 95% CI 1.7-2.7), (OR = 4.8, 95% CI 3.2-7.1)], and acute kidney injury [(OR = 2.5, 95% CI 1.9-3.2), (OR = 3.9), 95% CI 2.7-5.6)] were associated with both 30-day morbidity and mortality. Delayed presentation was associated with 30-day morbidity [OR = 1.3, 95% CI 1.1-1.6], but not mortality.