Purpose: Primary nonresponse (1NR) - inability to achieve adequate weight loss after surgery - and secondary nonresponse (2NR) - excessive weight regain after initial adequate weight loss after surgery - can occur in up to 25-35% of patients after bariatric surgery. The aim of this study was to explore the variations in both definition as well as management of 1NR and 2NR amongst bariatric surgeons.
Materials and methods: An online survey was distributed to all members of the national bariatric societies in the Netherlands and Belgium regarding questions about definition, work-up and treatment of 1NR and 2NR after bariatric surgery.
Results: A total of 45 responses from bariatric surgeons were obtained, representing 32 medical centers that perform bariatric procedures. When assessing 1NR, excess weight loss(EWL) was reported to be used by most respondents(30/45), total body weight loss(TBWL) by 18/45 and body mass index(BMI) by 25/45. A great variation in cut off values was observed. When assessing 2NR, percentage weight gain from the lowest (nadir) weight was preferred most by 22/45 respondents with cut off values varying from 5 to 20%. Most respondents deemed 18 months after initial surgery the most appropriate timeframe to determine 1NR or 2NR.
Conclusions: The current practice regarding primary and secondary nonresponse after bariatric surgery has a wide variety in definitions, work-up and treatment options. Consensus on the definition of 1NR and 2NR is needed to optimize the treatment of bariatric patients.
Keywords: Bariatric surgery; Primary nonresponse; Secondary nonresponse; Weight loss failure; Weight regain.