GENEVA: No difference in 30-day morbidity and mortality of SG, RYGB and OAGB patients

There is no significant difference in the 30-day morbidity and mortality of sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one anastomosis gastric bypass (OAGB) patients in propensity score-matched cohorts, according to the latest paper from Global 30-day outcomes of bariatric surgEry iN thE coVid-19 erA (GENEVA) collaboration. The paper, ‘30-day morbidity and mortality of sleeve gastrectomy, Roux-en-Y gastric bypass and one anastomosis gastric bypass: a propensity score-matched analysis of the GENEVA data’, featured in the International Journal of Obesity, was written on behalf of the GENEVA Collaborators.

GENEVA is a multi-centre observational cohort study of bariatric and metabolic surgery (BMS) in 185 centres across 42 countries May and October 2020 during the Coronavirus Disease-2019 (COVID-19) pandemic. Thirty-day complications were categorised according to the Clavien–Dindo classification. Patients receiving SG, RYGB, or OAGB were propensity-matched according to baseline characteristics and 30-day complications were compared between groups.


This analysis included 6,770 patients (SG 3983; OAGB 702; RYGB 2085) and the authors noted multiple significant differences in baseline demographics between the three groups; RYGB patients were significantly older than patients in the other two cohorts; patients receiving OAGB were more likely to suffer from co-morbidities; and patients undergoing SG had the lowest rate of each of these co-morbidities.


The overall complication rate was 6.7% (452/6770) with RYGB patients having the highest rate of any complication during the 30-day follow-up (8.0% with RYGB vs 7.5% for OAGB and 5.8% for SG, p=0.006). There were seven post-operative mortalities (0.1%) (four with SG, three with OAGB, p=0.016).


After carrying out multivariate regression modelling, the authors found that insulin-dependent T2DM and hypercholesterolaemia were associated with increased 30-day complications, being a non-smoker was associated with reduced complication rates.


“This is important because T2DM is known to be associated with complications after bariatric surgery and in our study, Insulin-dependent T2DM was independently associated with 30-day morbidity on multivariate analysis of the unmatched cohort,” the authors noted.

When compared to SG as the reference category, RYGB, but not OAGB, was associated with an increased rate of 30-day complications.


Standardised mean differences in age, BMI, sex, smoking status, hypertension rates were all reduced after matching for both the matched comparisons involving SG in this study.


“Given that all of these characteristics are known to be associated with increased morbidity after bariatric surgery, differences in these baseline characteristics may have been in part responsible for why the observed difference in morbidity between SG and RYGB or OAGB disappeared after matching,” the authors explained. “At the same time, and probably because of the fewer number of bypass procedures in the GENEVA database, matching failed to reduce SMDs for age, sex, smoking status, and hypertension in the comparison between OAGB and RYGB in this study.”


Further information

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