Bariatric surgery: the long-term health benefits and potential complications
Bariatric surgery is the most clinical – and cost-effective treatment for severe obesity[1-4]. In England, on average, 6500-7000 procedures are performed annually and around 75,000 patients had bariatric surgery between 2008-2019[5-6]. Bariatric surgery works by influencing complex biological processes including influencing the gut hormones that control appetite and satiety, reducing the absorption of nutrients, and mechanical effects. Information about the different bariatric surgery procedures can be found here.
Bariatric surgery has multiple health benefits, for example improvements in type 2 diabetes mellitus, hypertension and obstructive sleep apnoea, and reductions in overall mortality[4,6-9]. Despite these significant benefits, in the long-term bariatric surgery can result in multiple issues including nutritional deficiencies[10-13]. Micronutrient deficiencies can be common after bariatric surgery, for example the reported prevalence of iron deficiency is 30%, vitamin B12 19-35%, folic acid 9-39% and vitamin D 25-73%. Several studies have suggested that those who do not have regular follow-up are more likely to have poorer outcomes, including developing nutritional deficiencies[15-19]. In addition to nutritional issues, patients may experience psychological issues post-bariatric surgery, and some may experience complications from surgery such as internal hernias, ulcers or post-prandial hypoglycaemia[20-26]. Patients who have bariatric surgery tend to have obesity related co-morbidities pre-surgery, which will need to continue to be monitored following surgery (initially this may need to be more frequent during rapid weight loss post-surgery).
Lifelong nutritional care after bariatric surgery
The National Institute for Heath and Care Excellence (NICE) have recognised the importance of follow-up for these patients and NICE CG189 recommended patients have specialist follow-up with their bariatric surgery team for the first 2 years post-surgery and are then discharged to GPs to continue to have lifelong annual reviews (including nutritional monitoring) under a shared-care model. Other organisations such as the European Association for the Study of Obesity and the National Confidential Enquiry into Patient Outcome and Death have also highlighted the importance of long-term follow-up for patients after bariatric surgery.
Guidance for nutritional monitoring and supplementation: annual nutritional reviews in primary care
In the UK, the British Obesity and Metabolic Surgery Society (BOMSS) have published detailed guidelines for nutritional monitoring and management of patients who have had bariatric surgery. However, given the length of the document, it is not easily accessible for GPs. Therefore, a working group comprising GPs, bariatric dietitians and a chemical pathologist, with expertise in obesity and bariatric surgery, was formed to develop a more accessible summary of BOMSS nutritional guidance to support GPs with the lifelong management of patients after bariatric surgery, which can be found here.
It is important to note that a full annual review includes medical, nutritional and psychological components. On this webpage you will also find links to more detailed guidance for GPs for post-bariatric surgery annual reviews, including a pre-consultation questionnaire for patients and a GP consultation guide.
A full post-bariatric review may appear burdensome, but it should be noted that much of a post-bariatric annual review overlaps with other long-term condition reviews and/or a medication review routinely conducted in primary care. It also provides an opportunity to identify any difficulties as early as possible and may prevent significant care needs in the future.
The challenges: commissioning for shared-care after bariatric surgery
There is still a lack of commissioned shared-care services to provide long-term post-bariatric surgery follow-up, both in primary and secondary care. There is an urgent need to develop this, including considering new virtual consultations; for those involved in commissioning, some potential shared-care models can be found at here.
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© BOMSS and the authors 2023