Bariatric surgery
BioMG follows French guidelines. Adapt it to the guidelines and the tests available where you practise.
Before surgery: nutritional work-up
Laboratory tests
- FBC (haemoglobin)
- Serum albumin
- Serum ferritin
- Serum calcium
- PTH
- 25-hydroxyvitamin D (reimbursed in France)
- Vitamin B9 (folate)
- Vitamin B12
- Zinc
- Selenium
- HbA1c (diabetes)if neededKnown diabetes: an HbA1c ≥ 9% leads to postponing the procedure while glycaemic control is optimised [4].
Do not order
After bariatric surgery: follow-up
Fasting laboratory tests
- FBC
- ASTif neededLiver abnormality or metabolic steatotic liver disease found at the preoperative liver assessment (transaminases, GGT, FIB-4) [4]: see the dedicated page. These tests are not on the HAS minimum postoperative monitoring list [4]; the 2020 UK guideline advises instead monitoring liver function at 3, 6 and 12 months, then at least once a year, to follow steatotic liver disease and detect hypoalbuminaemia [6].
- ALTif neededLiver abnormality or metabolic steatotic liver disease found at the preoperative liver assessment (transaminases, GGT, FIB-4) [4]: see the dedicated page. These tests are not on the HAS minimum postoperative monitoring list [4]; the 2020 UK guideline advises instead monitoring liver function at 3, 6 and 12 months, then at least once a year, to follow steatotic liver disease and detect hypoalbuminaemia [6].
- Serum creatinine with eGFR
- Serum electrolytes
- Serum calcium
- Serum phosphate
- PTH
- 25-hydroxyvitamin D (reimbursed in France)
- Serum albumin
- Prealbuminif neededNutritional work-up guided by the clinical picture (pace of weight loss, vomiting) and the technique: the 2011 HAS recommendation cites prealbumin together with serum albumin [9]; the 2024 one does not retain it in the minimum list [4].
- Serum ferritin
- CRP
- Transferrin iron saturationif neededInflammatory context (raised CRP) or non-contributory ferritin: HAS recommends adding serum iron and transferrin, which give the saturation [10]. The 2011 HAS recommendation on obesity surgery cited this saturation in the nutritional work-up guided by the clinical picture [9]; the 2024 one does not retain it in the minimum list [4].
- Zinc
- Serum magnesium
- Vitamin B9 (folate)
- Vitamin B12
- Fasting plasma glucoseif neededType 2 diabetes before the operation: more regular follow-up, adjustment of treatments to avoid hypoglycaemia [4]; see the page "Type 2 diabetes".
- Lipid profileif neededOn a statin for primary prevention: dose halved for 6 months, LDL cholesterol reassessed at 6 months, 1 year, then every year [4].
- Vitamin A (high-malabsorption surgery)if neededSurgery with a high level of malabsorption (short common limb, under 3 metres: duodenal switch, SADI-S, omega-loop bypass) [4]. Measurement to be completed with RBP and vitamin K [4].
- RBP (retinol binding protein) (high-malabsorption surgery)if neededSurgery with a high level of malabsorption (short common limb, under 3 metres: duodenal switch, SADI-S, omega-loop bypass): HAS completes the vitamin A measurement with RBP [4].
- Vitamin E (high-malabsorption surgery)if neededSurgery with a high level of malabsorption (short common limb, under 3 metres: duodenal switch, SADI-S, omega-loop bypass) [4].
- Vitamin K (high-malabsorption surgery)if neededSurgery with a high level of malabsorption (short common limb, under 3 metres: duodenal switch, SADI-S, omega-loop bypass) [4].
- Serum copper (high-malabsorption surgery)if neededSurgery with a high level of malabsorption (short common limb, under 3 metres: duodenal switch, SADI-S, omega-loop bypass) [4].
- Serum copper (if Roux-en-Y gastric bypass, at least once a year)if needednon-French guidelineRoux-en-Y gastric bypass: US guidelines (AACE/TOS/ASMBS 2019) propose looking for copper deficiency at least once a year, even without clinical signs, in particular in case of anaemia or neutropenia [7]; the UK BOMSS also proposes it after sleeve gastrectomy [6]. HAS reserves this test for surgery with a high level of malabsorption [4].
Do not order
- Routine measurement of vitamin B1: HAS asks for clinical vigilance and probabilistic treatment with thiamine at the slightest sign, not routine measurement [4].
- Vitamins A, E, K and copper after gastric band, sleeve or Roux-en-Y bypass without a warning sign: reserved for surgery with a high level of malabsorption [4].
Gastrectomy other than bariatric surgery (stomach cancer): follow-up
Laboratory tests, once a year
- FBC
- Serum ferritin (if anaemia)if neededAnaemia on the FBC: look for iron deficiency (see the page "Iron deficiency").
- Vitamin B9 (folate) (if macrocytic anaemia)if neededMacrocytic anaemia: the reference text possibly adds folate to vitamin B12 after total gastrectomy [12].
- After total gastrectomy: vitamin B12 1 mg IM every 3 to 12 months, lifelong (supplementation, no assay planned) [12].
Also consider
- Gastrectomy, B12 to check? After gastrectomy, see the page "Low vitamin B12 or suspected B12 deficiency".
- Anaemia after gastrectomy? In case of anaemia, the work-up follows the tabs of the "Anaemia" page.
Sources (14)
- Oberlin P, de Peretti C. Chirurgie de l'obésité : 20 fois plus d'interventions depuis 1997. Études et Résultats, DREES, n° 1051, février 2018.
- Assurance maladie. Nomenclature des actes de biologie médicale (NABM), version 105 : actes 0983 (parathormone), 1139 (25-OH-vitamine D) et 2003 (zinc).
- Assurance maladie. Nomenclature des actes de biologie médicale (NABM), version 105 : acte 1818 (RBP) ; absence d'acte pour le sélénium et la vitamine K.
- Haute Autorité de santé. Obésité de l'adulte : prise en charge de 2e et 3e niveaux. Partie II : pré- et post-chirurgie bariatrique. Recommandations de bonne pratique, validées par le Collège le 8 février 2024.
- Haute Autorité de santé. Obésité de l'adulte : prise en charge de 2e et 3e niveaux. Partie II : pré et post-chirurgie bariatrique. Fiche, février 2024.
- O'Kane M, Parretti HM, Pinkney J, et al. British Obesity and Metabolic Surgery Society Guidelines on perioperative and postoperative biochemical monitoring and micronutrient replacement for patients undergoing bariatric surgery - 2020 update. Obes Rev. 2020;21(11):e13087.
- Mechanick JI, Apovian C, Brethauer S, et al. Clinical practice guidelines for the perioperative nutrition, metabolic, and nonsurgical support of patients undergoing bariatric procedures – 2019 update: cosponsored by American Association of Clinical Endocrinologists/American College of Endocrinology, The Obesity Society, American Society for Metabolic & Bariatric Surgery, Obesity Medicine Association, and American Society of Anesthesiologists. Endocr Pract. 2019;25(12):1346-1359 (texte complet en ligne).
- Nederlandse Vereniging voor Heelkunde (Federatie Medisch Specialisten). Richtlijn Chirurgische behandeling van obesitas : modules « Work-up voorafgaand aan chirurgische behandeling van obesitas » et « Medische nazorg & follow-up na chirurgische behandeling van obesitas », publiés le 28/10/2020 (Richtlijnendatabase, Pays-Bas).
- Obésité : prise en charge chirurgicale chez l’adulte
- Haute Autorité de santé. Choix des examens du métabolisme du fer en cas de suspicion de carence en fer. Rapport d'évaluation, texte court, novembre 2011.
- Shiau J, Biertho L. Canadian Adult Obesity Clinical Practice Guidelines: Bariatric Surgery: Postoperative Management. Obésité Canada, version 1, 4 août 2020.
- Société nationale française de gastro-entérologie (SNFGE), FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO et al. Thésaurus national de cancérologie digestive (TNCD), chapitre 2 : Cancer de l'estomac. Version du 22/04/2026.
- National Institute for Health and Care Excellence. Oesophago-gastric cancer: assessment and management in adults. NICE guideline NG83, janvier 2018, mise à jour juillet 2023 ; recommandations 1.6 et 1.7.
- Suivi après chirurgie bariatrique