Complications Rate Variability after Bariatric Surgery and the Importance of Standardization of a Reporting System.

Background: The rate of early (< 30 days) complications after bariatric surgery has been reported to be 0.4-27.4%. Although the incidence of serious adverse events has decreased with time and experience, controversy regarding how they are reported persists, and the current literature is heterogeneous.

Methods: Data from patients, who underwent primary bariatric surgery (gastric bypass and sleeve gastrectomy) at a single institution between 2012 and 2018, were retrospectively reviewed. Any deviation from a "normal" postoperative course (< 30 days) was identified, and a comparative analysis of early complications according to five models was performed: modified Clavien-Dindo; Longitudinal Assessment of Bariatric Surgery (LABS); Bariatric Surgery Centers of Excellence (BSCOE); American Society for Metabolic and Bariatric Surgery (ASMBS); and Li (major/minor).

Results: A total of 788 patients (83.7% gastric bypass), of whom 8.8% deviated from a "normal" postoperative course, were included. After applying the five classifications, the results were as follows: Clavien-Dindo, 8.8%; LABS, 2.3%; BSCOE, 0.4%; ASMBS, 9.9%; and Li, 11.2%. The incidence of major/severe/adverse outcomes were as follows: Clavien-Dindo, 2.4%; LABS, 2.3%; BSCOE, 0.4%; ASMBS, 6.9%; and Li 9.2%. Minor complications were as follows: Clavien-Dindo, 6.5%; ASMBS, 3%; and Li, 2%. There was no mortality.

Conclusion: Germane heterogeneity was found in reporting of early complications after bariatric surgery. Incidence varied according to classification system applied, and Clavien-Dindo demonstrated accuracy as a reporting model. To avoid bias, standardized reporting should be mandatory, and a more stringent and homogeneous reporting system should be established.