Table 5.
Preoperative evaluation before metabolic surgery in individuals with diabetes and obesity
|
System
|
Essential evaluation
|
Conditional evaluation
|
Comments
|
| History and physical examination | Detailed evaluation along with drug history | - | - |
| Glycemic | FPG, PPG, HbA1c, Fasting serum C-peptide | SMBG; CGMS | HbA1c < 7% is a reasonable target, higher targets may be acceptable in long-standing diabetes; SMBG and/or CGMS in patients on insulin |
| Cardiovascular | BP: Fasting lipid Profile; ECG: Cardiovascular risk assessment with a validated risk prediction model1 | Transthoracic echocardiography (in cases with unexplained dyspnea and known cases of heart failure, especially with recent changes in clinical status); If risk ≥ 1%,2 functional status assessment. Poor (< 4 METs) or unknown functional capacity - exercise or pharmacological stress echocardiography or radionuclide MPI | Target BP < 140/90; Abnormal results in a stress test should be managed according to current clinical practice guidelines. Patients with underlying cardiac abnormalities should undergo a formal cardiology consultation before surgery |
| Pulmonary | Smoking history. Screening for OSA by a clinical scoring tool3. .Risk assessment for VTE during perioperative period by a validated method4 | Pulmonary function test in presence of intrinsic pulmonary disease; Overnight polysomnography if indicated from results of scoring tool. ABG for PaCO2 estimation and venous bicarbonate in cases of OSA to rule out OHS | Structured tobacco cessation program if applicable |
| Gastrointestinal | - | UGIE to be considered routinely before LSG. Conditional for other procedures; H pylori detection and eradication | |
| Hepatic | LFT | Abdominal USG if LFT deranged or symptomatic biliary disorder. Use of Noninvasive scoring systems5 can be considered. Liver elastography; Three-dimensional magnetic resonance elastography; Intraoperative liver biopsy | The strategy to diagnose NAFLD in bariatric patients is not defined. Variations of liver elastography such as transient elastography, 2-D shear wave elastography, and ARFI can be better modalities in severely obese patients. Intraoperative liver biopsy is the gold standard, but its specific indications are not clear |
| Renal, electrolytes, uric acid | Serum creatinine; eGFR6; Urinary albumin-creatinine ratio | Electrolytes in presence of CKD or drugs known to cause electrolyte imbalance. Uric acid if there is past history of gout | Serum potassium should be measured if on ACE inhibitors, ARBs, or diuretics |
| Nutritional | Nutritional assessment by a dietitian. Complete blood count, serum ferritin, serum iron, TIBC, and TS. Serum vitamin B12, folate. Serum calcium, 25(OH)D | Serum C-reactive protein if anemia of chronic inflammation is suspected. Serum methylmalonic acid and homocysteine in cases of low normal vitamin B12 and folate levels with high index of suspicion. Serum copper, zinc, and selenium; fat soluble vitamins such as vitamin A, E and K can be considered before malabsorptive procedures | Serum or urinary N-telopeptide, bone-specific alkaline phosphatase, and bone mineral density can be considered if osteoporosis is suspected especially in postmenopausal women |
| Endocrine | - | Thyroid profile if there is a past history of thyroid dysfunction, goiter or symptoms suggestive of thyroid disorder. ONDST, 24-h urinary free cortisol, or 11-pm salivary cortisol if there is suspicion of endogenous Cushing’s syndrome | Evaluation of syndromic or monogenic obesity on case-by-case basis |
| Reproductive | - | Total and bioavailable testosterone and USG of the pelvis if PCOS is suspected. LH, FSH, and testosterone (total) if hypogonadism is suspected in males | Women should avoid pregnancy if planned for surgery. Pregnancy should be avoided for 12-18 mo after surgery |
| Psychological | Behavioral and psychosocial evaluation | - | - |
e.g., Revised Cardiac Risk Index, Obesity surgery mortality risk score, Longitudinal Assessment of Bariatric Surgery consortium risk stratification system, metabolic acuity score, etc.
Estimated perioperative mortality risk or major adverse cardiovascular risk of ≥ 1%.
STOP-BANG questionnaire or Berlin questionnaire.
e.g., venous thromboembolism risk assessment tool by Fink et al[130].
Non-alcoholic steatohepatitis clinical scoring system, AST to platelet ratio index, FIB-4 index, non-alcoholic fatty liver disease fibrosis score, BARD score and Forns index.
By Chronic Kidney Disease Epidemiology Collaboration formula.
25(OH)D: 25-hydroxyvitamin D; ABG: Arterial blood gas; ACE: Angiotensin converting enzyme; ARB: Angiotensin II receptor blocker; ARFI: Acoustic radiation force impulse shear wave imaging; CGMS: Continuous glucose monitoring system; eGFR: Estimated glomerular filtration rate; FPG: Fasting plasma glucose; FSH: Follicle-stimulating hormone; H. pylori: Helicobacter pylori; HbA1c: Glycated hemoglobin; LFT: Liver function test; LH: Luteinizing hormone; MET: Metabolic equivalent; MPI: Myocardial perfusion imaging; ONDST: Overnight dexamethasone suppression test; OSA: Obstructive sleep apnea; PCOS: Polycystic ovary syndrome; PPG: Post-prandial glucose; SMBG: Self-monitoring of blood glucose; TIBC: Total iron-binding capacity; TS: Transferrin saturation; UGIE: Upper gastrointestinal endoscopy; USG: Ultrasonography; VTE: Venous thromboembolism.