Tests Before Gastric Sleeve Surgery

Tests commonly done before a gastric sleeve include blood work, a review of your heart and lungs with screening for sleep apnea, a check of the stomach when indicated, a nutrition assessment and a psychological evaluation. The 2019 clinical practice guideline from ASMBS and four other societies sets out this work-up as a checklist. Its purpose is to assess surgical risk.

Why there is a work-up, and who decides what you need

A sleeve gastrectomy is planned surgery under general anesthesia, and it cannot be reversed. The 2019 guideline (Mechanick and colleagues) states that the evaluation before surgery "must include a comprehensive medical history, psychosocial history, physical examination, and appropriate laboratory testing to assess surgical risk." Some items apply to everyone. Others are ordered only when your history or examination points to them.

Two sets of requirements can apply to you: what your surgeon needs to operate, and what your insurer asks for before it will authorize surgery. They overlap but are not identical. The 2022 ASMBS/IFSO guidelines state that the decision about readiness for surgery "should be primarily determined by the surgeon." This page describes the guidelines, not the list for any one patient, so ask the office which tests Dr. Davtyan requires in your case and where each is done. Insurer rules are covered in insurance requirements for a gastric sleeve, and the usual order of events in from consultation to gastric sleeve surgery. Keep copies of recent lab, sleep study, heart test and endoscopy reports.

Blood and urine tests

The 2019 guideline's pre-procedure checklist lists these:

• Fasting blood glucose and a lipid panel (cholesterol and triglycerides)
• Kidney function and a liver profile
• A complete blood count, blood type and a clotting test (prothrombin time/INR)
• Urine analysis
• Nutrient screening: iron studies, vitamin B12, folic acid and vitamin D

Nutrient levels can show deficiencies that need attention before surgery. The same nutrients are followed afterwards; see vitamins and lab tests after a sleeve.

Some tests are added for particular situations. The guideline lists hemoglobin A1c for people with diabetes or prediabetes, and gives a reasonable pre-surgery target of 6.5% to 7.0% or less. It says routine thyroid screening is not recommended unless there are signs of thyroid disease, while noting that many insurance plans ask for a thyroid-stimulating hormone (TSH) level anyway. Women of childbearing age can expect pregnancy counselling. The guideline advises avoiding pregnancy before surgery and for 12 to 18 months after it; ask your surgeon about timing for you.

Heart, lungs and sleep

Heart

The guideline does not call for the same heart tests in everyone. It states that the need for an electrocardiogram (ECG, a tracing of the heart's rhythm) and other non-invasive cardiac testing "is determined on the basis of the individual risk factors and findings on history and physical examination." People with known heart disease need a formal cardiology consultation before surgery. An echocardiogram, an ultrasound of the heart, is listed for cases where heart disease or high pressure in the lung arteries is suspected.

Sleep apnea

Obstructive sleep apnea means the airway repeatedly narrows or closes during sleep. It matters for anesthesia and the first nights after surgery. The guideline says clinical screening "should be considered," with a sleep study (polysomnography) to confirm if the screening is positive. If you already use a CPAP machine, tell your surgeon and anesthesia team and ask whether to bring it to the hospital.

Blood clots

People with a history of deep vein thrombosis, a clot in a leg vein, should have a risk assessment and an appropriate diagnostic evaluation, according to the guideline. Tell the surgeon about any past clot, clotting disorder or blood thinner. Mention any estrogen-containing contraceptives or hormone therapy too.

Stomach and digestive tests

The sleeve is an operation on the stomach, so its condition matters.

• Upper endoscopy. A thin camera is passed through the mouth to look at the esophagus and stomach, usually under sedation. The 2019 guideline states that significant digestive symptoms should be evaluated before surgery and that endoscopy "may be considered in all patients being evaluated for sleeve gastrectomy." It can show reflux damage, ulcers or a hiatal hernia, which can change the plan. See hiatal hernia and the gastric sleeve and acid reflux after a gastric sleeve.
• H. pylori testing. Helicobacter pylori is a stomach bacterium linked to ulcers. The guideline says routine screening "may be considered in areas of high prevalence."
• Ultrasound. The guideline does not recommend imaging as a routine screen for liver disease. An abdominal ultrasound is indicated for symptoms of gallbladder disease or raised liver tests.

Psychological and nutrition evaluations

The 2019 guideline states that a formal psychosocial-behavioral evaluation by a qualified behavioral health professional "should be required for all patients before a bariatric procedure." It assesses environmental, family and behavioral factors, along with risk for suicide. Ask who would do this evaluation for you, and whether you can use your own therapist.

The guideline's checklist also includes a clinical nutrition evaluation by a registered dietitian. The 2022 ASMBS/IFSO guidelines note that an assessment by a dietitian with expertise in bariatric surgery can help obtain a comprehensive weight history and prepare you for the diet changes ahead. Ask whether the office has a dietitian or refers you to one. Some surgeons also prescribe a short pre-surgery liver diet.

Tobacco is addressed at this stage too. The guideline states that patients who smoke cigarettes "should stop as soon as possible, preferably 1 year, but at the very least, 6 weeks before bariatric procedures," and that tobacco must be avoided afterwards.

Frequently asked questions

Does everyone need an endoscopy before a gastric sleeve?

Practice varies. The 2019 guideline says endoscopy may be considered in all patients being evaluated for a sleeve, which leaves the decision to the surgeon. It is more likely to come up if you have heartburn, trouble swallowing, a history of ulcers or previous stomach surgery. Ask the office whether Dr. Davtyan would want one in your case.

Can I fail the psychological evaluation?

It is usually more than a simple pass or fail. An evaluator may recommend proceeding, proceeding with added support, or treating something first, such as an active eating disorder, untreated depression or heavy drinking. The 2019 guideline specifies a formal mental health evaluation for anyone with a known or suspected psychiatric illness or substance use problem. Honest answers help you get the right care.

Will I be tested for nicotine before surgery?

Programs differ, so ask the office about its policy. The reason for stopping is medical. The 2019 guideline cites a national database study in which smoking within a year before a sleeve was associated with higher 30-day complication and death rates, and it says tobacco must be avoided after surgery because of poor wound healing and ulcer risk.

Can my own doctors do the tests before a gastric sleeve?

That depends on the test, on your surgeon and on your insurance plan. Blood tests, an ECG, a sleep study or a cardiology visit arranged through your primary care doctor may or may not be accepted, and reports may need to be recent. Ask the office before you book anything so that nothing is missed or repeated, and check which providers your plan requires you to use.

Talk with Dr. Davtyan in Rancho Cucamonga

Dr. David G. Davtyan, MD, FACS, FICS, FASMBS, is a bariatric surgeon with Davtyan Medical Weight Loss & Wellness at 8330 Red Oak Street, Suite 201, Rancho Cucamonga, CA 91730. Call 909-355-2525 or toll free 877-9-BE-SLIM (877-923-7546), or use our contact page. The first consultation is complimentary, and Hablamos Español. More topics are in our Rancho Cucamonga gastric sleeve guide.

Sources

• Mechanick JI, et al. Clinical practice guidelines for the perioperative nutrition, metabolic, and nonsurgical support of patients undergoing bariatric procedures, 2019 update. Endocr Pract. 2019 (full-text copy hosted by the Commission on Dietetic Registration)
• Eisenberg D, et al. 2022 ASMBS and IFSO: Indications for Metabolic and Bariatric Surgery. Obes Surg. 2023

More in the Gastric Sleeve in Rancho Cucamonga guide

Start at the Gastric Sleeve in Rancho Cucamonga page, or go straight to a topic.

Understanding the sleeve

• Staple-Line Leak After Gastric Sleeve: Signs, Timing and Treatment
• Gastric Sleeve Stricture (Stenosis): Symptoms, Tests and Treatment
• Acid Reflux and GERD After Gastric Sleeve Surgery
• Hiatal Hernia and Gastric Sleeve Surgery
• Gallstones After Gastric Sleeve Surgery
• Hair Loss After Gastric Sleeve Surgery
• Nausea, Dehydration and Constipation After Gastric Sleeve Surgery
• Gastric Sleeve Emergency Warning Signs: When to Go to the ER
• Weight Regain After Gastric Sleeve: Why It Happens and What Can Be Done
• Vitamins and Lab Tests After a Gastric Sleeve
• Alcohol After a Gastric Sleeve: What Changes and What the Evidence Says
• Pregnancy After a Gastric Sleeve: Timing, Nutrition and Monitoring

Weighing your options

• Gastric Sleeve With a BMI of 30 to 34.9
• Gastric Sleeve With a BMI of 50 or More
• Gastric Sleeve Surgery After Age 60
• Gastric Sleeve and Type 2 Diabetes: What the Trials Show
• Tests Before Gastric Sleeve Surgery
• The pre-surgery liver diet before a gastric sleeve
• Insurance requirements for a gastric sleeve: how insurers decide
• What affects the cost of gastric sleeve surgery
• Converting a gastric sleeve to a gastric bypass
• Gastric sleeve in Mexico or near home: what to weigh
• Second opinions on gastric sleeve surgery: when and how
• Questions to ask a gastric sleeve surgeon

Getting care in Rancho Cucamonga

• Sleeve done elsewhere: how to move your follow-up care
• Gastric sleeve revision: reasons, tests and options
• Your first gastric sleeve consultation: what happens and what to bring
• From consultation to gastric sleeve surgery: the steps in order
• Gastric sleeve surgery day and the hospital stay
• Returning to work, driving, lifting and exercise after a gastric sleeve
• Gastric sleeve follow-up schedule: visits, labs and support
• Gastric sleeve care for Ontario, CA residents
• Gastric sleeve care for Fontana, CA residents
• Gastric sleeve care for Upland and Claremont residents
• Gastric sleeve care for Riverside and Corona residents
• Gastric sleeve care for San Bernardino and Redlands residents