Causes of death after bariatric surgery: long-term study of 10 years

Background There is a lack of up-to-date research addressing the causes of death and predictors of long-term mortality after bariatric surgery.

Methods This was a single-centre retrospective study. Trust records were used to identify deceased patients and their medical history. The demographic data, comorbidities, cause of death, and time since surgery were retrieved and tabulated. Data was recoded to allow for use in IBM SPSS.

Results There were 39 deaths amongst 891 patients who underwent bariatric surgery between 15th June 2010 to 18th September 2022. The main cause of death was pneumonia and respiratory causes with 15.4% of the cohort. A history of asthma/COPD had an association with the cause of death (p = 0.021). A history of hypertension, ischaemic heart disease (IHD), and smoking were all associated with a higher age at death, whilst a history of IHD was associated with a higher number of days from operation to death. Age at operation and number of comorbidities both correlated with age at death, and multiple linear regression of age at death with age at operation and number of comorbidities as predictors was significant (p < 0.001). A Cox regression found age at operation to have a significant effect on survival, with a hazard ratio of 1.063 (95% CI:1.027 to 1.100, p < 0.001).

Conclusion Pneumonia and respiratory causes are the largest causes of long-term mortality after bariatric surgery. The only factor found to have a detrimental effect on all-cause mortality was age at operation which reduced survival. Hypertension, IHD, and smoking are indirect factors that are associated with mortality.