WEIGHT LOSS PROCEDURES










  • Revisons of previous weight loss procedures
  • Reference: ASMBS website
Type of weight loss procedure performed in U.S. in 2019
(N=256,000 procedures)
Gastric sleeve 59.4%
Gastric bypass 17.8%
Revisional surgery 16.7%
Gastric balloon 1.8%
Gastric banding 0.9%
BPD/DS 0.9%
Other 2.4%




  • References [1 - 9]
Typical weight loss seen with obesity treatments
Treatment % weight loss from baseline
(length of follow-up)
BPD/DS 35 - 40%
(> 10 years)
Gastric bypass 30 - 35%
(> 10 years)
Gastric sleeve 25 - 30%
(> 10 years)
Gastric banding 20 - 25%
(> 10 years)
Wegovy (semaglutide) 16%
(68 weeks)
Intragastric balloon 10%
(6 months)
Appetite suppressants (e.g. phentermine) 10%
(6 months)
Qsymia (topiramate + phentermine) 10%
(56 weeks)
Saxenda (Liraglutide) 8%
(56 weeks)
Xenical (orlistat) 7.6%
(2 years)
Contrave (naltrexone + bupropion) 6.5%
(28 weeks)
Plenity (hydrogel) 6.4%
(24 weeks)









  • References [1,10,11]
Bariatric procedure long-term maintenance care
Gastric sleeve
  • Labs (annually in all patients)
    • CBC, CMP, Lipid profile
    • Vitamin B12
    • Vitamin D
    • Iron studies
  • Other
    • Avoid NSAIDs if possible. If taken, give with proton pump inhibitor (PPI).
    • History of kidney stones - consider 24-hr urinary calcium excretion
    • Bone mineral density (BMD) two years after procedure
  • Long-term complications
    • May worsen or cause new onset GERD
    • Gallstones (from rapid weight loss)
    • Sleeve stricture
    • Incisional hernia
    • Osteoporosis
Gastric bypass (RYGB)
  • Labs (annually in all patients)
    • CBC, CMP, Lipid profile
    • Vitamin B12
    • Vitamin D
    • Folic acid
    • Iron studies
    • Zinc (serum and plasma levels)
    • Copper (serum copper and ceruloplasmin)
  • Other
    • Avoid NSAIDs if possible. If taken, give with proton pump inhibitor (PPI).
    • History of kidney stones - consider 24-hr urinary calcium excretion
    • Bone mineral density (BMD) two years after procedure
  • Long-term complications
    • Malabsorption
    • Dumping syndrome
    • Gallstones (from rapid weight loss)
    • Anastomotic strictures
    • Bowel obstruction
    • Marginal ulceration
    • Gastrogastric fistula
    • Incisional and internal hernias
    • Osteoporosis
Gastric banding
  • Labs (annually in all patients)
    • CBC, CMP, Lipid profile
    • Vitamin B12
    • Vitamin D
    • Iron studies
  • Other
    • Avoid NSAIDs if possible. If taken, give with proton pump inhibitor (PPI).
    • History of kidney stones - consider 24-hr urinary calcium excretion
    • Bone mineral density (BMD) two years after procedure
  • Long-term complications
    • Band slippage over stomach
    • Band erosion through stomach
    • Swallowing problems
    • Enlargement of esophagus
    • Osteoporosis
Biliopancreatic diversion with duodenal switch (BPD/DS)
  • Labs (annually in all patients)
    • CBC, CMP, Lipid profile
    • Vitamin B12
    • Vitamin D
    • Vitamin A
    • Folic acid
    • Iron studies
    • Zinc (serum and plasma levels)
    • Copper (serum copper and ceruloplasmin)
    • 24-hour urinary calcium excretion at 6 months post-op and annually
  • Other
    • Avoid NSAIDs if possible. If taken, give with proton pump inhibitor (PPI).
    • Bone mineral density (BMD) two years after procedure
  • Long-term complications
    • Malabsorption
    • Dumping syndrome
    • May worsen or cause new onset GERD
    • Loose and frequent stools
    • Gallstones (from rapid weight loss)
    • Kidney stones (from hyperoxaluria, low urinary volume, and hypocitraturia)
    • Bowel obstruction
    • Incisional hernias
Pregnant patients
  • Patients who become pregnant after bariatric procedures should have increased surveillance for nutritional deficiencies during pregnancy
  • Check the following labs in all patients every trimester
    • Vitamin B12
    • Vitamin D
    • Calcium
    • Folic acid
    • Iron studies
  • For patients who have undergone RYGB or BPD/DS, also include:
    • Vitamin A
    • Vitamin E
    • Vitamin K
    • Zinc (serum and plasma levels)
    • Copper (serum copper and ceruloplasmin)

  • Reference [1]
Vitamin and mineral recommendations
Vitamin B1 (thiamine)
  • Prevalence of deficiency
    • Up to 49% of patients, depending on procedure and length of follow-up
  • Screening
    • Screen high-risk groups during the first 6 months and every 3 - 6 months as needed
    • High-risk groups include the following:
      • Females
      • Blacks
      • Patients not attending a nutritional clinic after surgery
      • Patients with GI symptoms (intractable nausea and vomiting, jejunal dilation, megacolon, or constipation)
      • Patients with concomitant conditions, such as cardiac failure (especially those receiving furosemide)
      • Patients with small bowel bacterial overgrowth
      • Other risk factors such as malnutrition, excessive and/or rapid weight loss, and excessive alcohol use increase the risk of thiamine deficiency
  • Prevention
    • All patients should consume ≥ 12 mg of thiamine daily, preferably as 50 - 100 mg/day from a B-complex supplement or high-potency multivitamin
  • Treatment
    • Oral: 100 mg 2 - 3 times daily until symptoms resolve
    • IM: 250 mg once daily for 3–5 d or 100–250 mg monthly
    • Magnesium, potassium, and phosphorus should be given simultaneously to patients at risk for refeeding syndrome

Vitamin B12 (cobalamin)
  • Prevalence of deficiency
    • Gastric bypass (2 - 5 years post-op): < 20%
    • Gastric sleeve (2 - 5 years post-op): 4 - 20%
  • Screening
    • Screen all patients annually
    • For patients who take medications that can lower B12 levels (e.g. nitrous oxide, neomycin, metformin, colchicine, proton-pump inhibitors, seizure medications), screen every 3 months in the first year and then annually
    • See vitamin B12 deficiency diagnosis
  • Prevention (all patients)
    • One of the following:
      • Oral supplement (disintegrating tablet, sublingual, or liquid) with 350 - 1000 mcg daily
      • Nasal spray as directed by manufacturer
      • Parenteral (IM or SQ): 1000 mcg monthly
  • Treatment
Folic acid (folate)
  • Prevalence of deficiency
    • Up to 65% of patients
  • Screening
    • Screening is recommended in all patients, particularly after RYGB or BPD/DS and in women of childbearing potential
    • Guidelines do not give a recommended interval
  • Prevention (all patients)
    • 400 - 800 mcg daily in a multivitamin
    • Women of childbearing potential should receive 800 - 1000 mcg/day
  • Treatment
    • Folic acid 1000 mcg daily until levels become normal, then resume normal supplementation
Iron
  • Prevalence of deficiency
    • BPD/DS: up to 62%
    • RYGB: 20 - 55%
    • Gastric sleeve: < 18%
    • Gastric balloon: 14%
  • Screening
    • Screen all patients within 3 months after surgery, every 3 - 6 months until 12 months post-op, then annually
    • Screening labs should include ion studies, ferritin, CBC, and soluble transferrin receptor (if available)
  • Prevention
    • Males and patients without a history of anemia: 18 mg of iron from a multivitamin
    • Menstruating females and patients who have undergone RYGB, gastric sleeve, or BPD/DS: 45 - 60 mg of elemental iron daily (cumulatively, including iron from all vitamin and mineral supplements)
  • Treatment
Vitamin D and calcium
  • Prevalence of deficiency
    • Up to 100% of patients
  • Screening
    • Gastric sleeve, RYGB, BPD/DS: screen annually
    • Recommended vitamin D assay is 25-hydroxyvitamin D (calcidiol)
  • Prevention
    • Calcium (recommended amount from all sources)
      • BPD/DS: 1800 - 2400 mg/day
      • Gastric band, gastric sleeve, RYGB: 1200 - 1500 mg/day
    • Vitamin D
      • Vitamin D level < 30 ng/ml: vitamin D3 3000 IU once daily
  • Treatment
    • Calcium (supplement)
      • BPD/DS: 1800 - 2400 mg/day
      • Gastric band, gastric sleeve, RYGB: 1200 - 1500 mg/day
    • Vitamin D
      • Vitamin D3 3000 - 6000 IU daily, or vitamin D2 50,000 IU one to three times weekly
Vitamin A
  • Prevalence of deficiency
    • Mostly seen after BPD/DS (up to 70% of patients within 4 years post-op)
  • Screening
    • BPD/DS and RYGB: screen within the first post-op year and as needed
  • Prevention
    • RYGB and gastric sleeve: 5000 - 10,000 IU/day
    • Gastric band: 5000 IU/day
    • BPD/DS: 10,000 IU/day
  • Treatment
    • Without corneal changes: vitamin A 10,000 – 25,000 IU/day should be given orally until clinical improvement is evident
    • With corneal changes: vitamin A 50,000 - 100,000 IU/day intramuscularly for 3 days, followed by 50,000 IU/day intramuscularly for 2 weeks
    • Evaluate for concurrent iron and/or copper deficiencies because these can impair the resolution of vitamin A deficiency
Vitamin E
  • Prevalence of deficiency
    • Uncommon
  • Screening
    • Only recommended if patients have symptoms of deficiency which include loss of feeling in the arms and legs, loss of body movement control, muscle weakness, and vision problems
  • Prevention
    • 15 mg/day
  • Treatment
    • 100 - 400 IU/day
Vitamin K
  • Prevalence of deficiency
    • Uncommon
  • Screening
    • Only recommended if patients have symptoms of deficiency which include excessive bleeding or bruising
  • Prevention
    • BPD/DS: 300 mcg/day
    • RYGB and Gastric sleeve: 90 - 120 mcg/day
    • Gastric banding: 90 - 120 mcg/day
  • Treatment
    • Acute malabsorption: 10 mg parenteral
    • Chronic malabsorption: 1 - 2 mg/day orally or 1 - 2 mg/week parenterally
Zinc
  • Prevalence of deficiency
    • BPD/DS: up to 70%
    • RYGB: up to 40%
    • Gastric banding: up to 34%
    • Gastric sleeve: up to 19%
  • Screening
    • Screen RYGB and BPD/DS patients at least annually. Symptoms of zinc deficiency include chronic diarrhea, hair loss, pica, significant dysgeusia, unexplained hypogonadism (males), and erectile dysfunction
    • Zinc is absorbed in the duodenum and proximal jejunum, so procedures that bypass or shorten these areas have a higher risk
    • Serum and plasma zinc levels are the preferred screening method
  • Prevention
    • BPD/DS: multivitamin with minerals containing 200% of the RDA (16 - 22 mg/day)
    • RYGB: multivitamin with minerals containing 100 - 200% of the RDA (8 - 22 mg/day)
    • Gastric sleeve and gastric banding: multivitamin with minerals containing 100% of the RDA (8 - 11 mg/day)
    • The supplementation protocol should contain a ratio of 8 - 15 mg of supplemental zinc per 1 mg of copper to minimize the risk of copper deficiency
  • Treatment
    • There is insufficient evidence to make a recommendation. Repletion doses should be chosen carefully to avoid inducing a copper deficiency.
Copper
  • Prevalence of deficiency
    • BPD/DS: up to 90%
    • RYGB: 10 - 20%
  • Screening
    • Screen RYGB and BPD/DS patients at least annually. Signs of copper deficiency include anemia, neutropenia, myeloneuropathy, and impaired wound healing.
    • Serum copper and ceruloplasmin are recommended biomarkers for determining copper status because they are closely correlated with physical symptoms of copper deficiency
  • Prevention
    • BPD/DS and RYGB: 200% of the RDA (2 mg/day)
    • Gastric sleeve and Gastric banding: 100% of the RDA (1 mg/day)
    • Copper gluconate or sulfate is the recommended source of copper for supplementation
    • Supplementation with 1 mg copper is recommended for every 8 - 15 mg of elemental zinc to prevent copper deficiency
  • Treatment
    • Mild to moderate (including low hematologic indices): 3 - 8 mg/day oral copper gluconate or sulfate until indices return to normal
    • Severe: 2 - 4 mg/day intravenous copper can be initiated for 6 days or until serum levels return to normal and neurologic symptoms resolve
    • Copper levels should be monitored every 3 months after they return to normal
Selenium
  • Prevalence of deficiency
    • Single-anastomosis duodeno-ileal bypass with sleeve: up to 50%
    • Gastric sleeve or gastric banding: up to 16% of patients at 18 months post-op
  • Screening
    • There is insufficient evidence to recommend routine screening. Selenium levels may be checked as part of aggressive case finding in patients with a malabsorptive bariatric surgical procedure who have unexplained anemia or fatigue, persistent diarrhea, cardiomyopathy, or metabolic bone disease.
  • Prevention
    • Oral supplement with greater than 55 mcg/day
  • Treatment
    • No recommendation




SM-BOSS trial - Gastric Sleeve vs Gastric Bypass for Weight Loss Over 5 Years, JAMA (2018) [PubMed abstract]
  • The SM-BOSS trial enrolled 217 morbidly obese adults in Switzerland
Main inclusion criteria
  • Age 18 - 65 years
  • BMI > 40 or > 35 with ≥ 1 comorbidity
  • Failed conservative treatments for 2 years
Main exclusion criteria
  • Severe GERD despite meds
  • Large hiatal hernia
  • Previous bariatric surgery
  • Inflammatory bowel disease
Baseline characteristics
  • Average age 43 years
  • Female sex - 72%
  • Average weight - 273 lbs (124 kg)
  • Average BMI - 44
  • Type 2 DM - 25%
Randomized treatment groups
  • Group 1 (107 patients): Laparoscopic sleeve gastrectomy
  • Group 2 (110 patients): Laparoscopic Roux-en-Y gastric bypass (RYGB)
Primary outcome: Weight loss, defined as percentage excess BMI loss (100 × [baseline BMI − follow-up BMI]/[baseline BMI − 25]), over a 5-year period
Results

Duration: 5 years
Outcome Gastric sleeve RYGB Comparisons
Weight loss 73 lbs (33 kg) 81 lbs (36.6 kg) p=0.19
Percent weight loss 25% 28.6% p=0.02
Primary outcome (excess BMI loss) 61% 68% p=0.22
Post-op intervention 15.8% 22.1% N/A
Overall mortality 0% 1.9% N/A
  • Weight loss nadir was reached between years 1 and 2 in both groups
  • In the gastric sleeve group, 9 patients underwent conversion to RYGB during follow-up due to GERD

Findings: Among patients with morbid obesity, there was no significant difference in excess BMI loss between laparoscopic sleeve gastrectomy and laparoscopic Roux-en-Y gastric bypass at 5 years of follow-up after surgery.






SM-BOSS trial - Gastric Sleeve vs Gastric Bypass for Weight Loss Over 5 Years, JAMA (2018) [PubMed abstract]
  • The SM-BOSS trial enrolled 217 morbidly obese adults in Switzerland
Main inclusion criteria
  • Age 18 - 65 years
  • BMI > 40 or > 35 with ≥ 1 comorbidity
  • Failed conservative treatments for 2 years
Main exclusion criteria
  • Severe GERD despite meds
  • Large hiatal hernia
  • Previous bariatric surgery
  • Inflammatory bowel disease
Baseline characteristics
  • Average age 43 years
  • Female sex - 72%
  • Average weight - 273 lbs (124 kg)
  • Average BMI - 44
  • Type 2 DM - 25%
Randomized treatment groups
  • Group 1 (107 patients): Laparoscopic sleeve gastrectomy
  • Group 2 (110 patients): Laparoscopic Roux-en-Y gastric bypass (RYGB)
Primary outcome: Weight loss, defined as percentage excess BMI loss (100 × [baseline BMI − follow-up BMI]/[baseline BMI − 25]), over a 5-year period
Results

Duration: 5 years
Outcome Gastric sleeve RYGB Comparisons
Weight loss 73 lbs (33 kg) 81 lbs (36.6 kg) p=0.19
Percent weight loss 25% 28.6% p=0.02
Primary outcome (excess BMI loss) 61% 68% p=0.22
Post-op intervention 15.8% 22.1% N/A
Overall mortality 0% 1.9% N/A
  • Weight loss nadir was reached between years 1 and 2 in both groups
  • In the gastric sleeve group, 9 patients underwent conversion to RYGB during follow-up due to GERD

Findings: Among patients with morbid obesity, there was no significant difference in excess BMI loss between laparoscopic sleeve gastrectomy and laparoscopic Roux-en-Y gastric bypass at 5 years of follow-up after surgery.

















Orbera plus Lifestyle Intervention vs Lifestyle Intervention for Obesity, International Journal of Obesity (2017) [PubMed abstract]
  • The trial enrolled 255 obese adults with a BMI of 30 - 40
Main inclusion criteria
  • BMI 30 - 40
  • Obesity for at least 2 years
  • Failed conservative weight loss (e.g. diet, exercise)
Main exclusion criteria
  • History of GI surgery (except appy or choly)
  • History of GI obstruction
  • GI motility disorder
  • Significant hiatal hernia
  • Positive H pylori at screening
  • Inflammatory bowel disease
Baseline characteristics
  • Average age 39 years
  • Female sex - 90%
  • Average weight - 215 pounds
  • Average BMI - 35
Randomized treatment groups
  • Group 1 (125 patients) - Orbera intragastric balloon for 6 months + Lifestyle intervention
  • Group 2 (130 patients) - Lifestyle intervention
  • The 12-month lifestyle intervention program incorporated the following elements: a low calorie (1000–1500 calories per day) diet, daily food and exercise diary, encouragement to exercise and emphasis on behavioral change during a total of 21 visits (9 visits in months 1–6, 12 visits in months 7–12)
Primary outcome: Difference in the average percent excess weight loss (%EWL) between groups at 9 months and difference in patients with ≥ 15% EWL at 9 months. Percent excess weight loss = Weight loss/(actual body weight - body weight if BMI was 25) X 100.
Results

Duration: 12 months
Outcome Orbera + Lifestyle Lifestyle Comparisons
Weight loss (6 months) 21.8 lbs (9.9 kg) | 10.2% 7 lbs (3.2 kg) | 3.3% p<0.001
Weight loss (9 months) 19.4 lbs (8.8 kg) | 9.1% 7 lbs (3.2 kg) | 3.4% p<0.001
Weight loss (12 months) 16.3 lbs (7.4 kg) | 7.6% 6.8 lbs (3.1 kg) | 2.9% p<0.001
Primary outcome (%EWL at 9 months) 26.5% 9.7% N/A
Primary outcome (≥15% EWL at 9 months) Orbera 45.6% more than control p<0.001
  • The study had a run-in phase where an additional 35 patients received the Orbera device. Of the total number of patients who received the device (N=160), 30 (18.8%) had it removed early due to side effects or intolerance.
  • Side effects in the Orbera group included the following: nausea (87%), vomiting (76%), abdominal pain (58%), GERD (30%), burping (24%), dyspepsia (21%), constipation (20%)

Findings: Intragastric balloon achieved greater short-term weight loss at 3 and 6 months postballoon removal than lifestyle intervention alone. Adverse gastrointestinal events were common.






PATHWAY trial - AspireAssist vs Control for Weight Loss (2015)
  • The PATHWAY trial enrolled 171 obese patients with a BMI of 35 - 55
Main inclusion criteria
  • BMI 35 - 55
  • 21 - 65 years old
  • Failed at least 3 months of conservative weight loss measures
  • No weight change > 3% within 3 months
Main exclusion criteria
  • Previous upper GI surgery or pathology that would interfere with gastrostomy tube
  • Refractory gastric ulcers
  • Inflammatory bowel disease
  • Diabetes treated with insulin or sulfonylurea
  • HgA1C > 9.5%
  • Significant pulmonary or cardiovascular disease
  • Osteoporosis
  • Taking medications that cause weight loss within 3 months
Baseline characteristics
  • Average age 44 years
  • Average BMI - 41
  • Average weight - 251 lbs (114 kg)
  • Female sex - 87%
Randomized treatment groups
  • Group 1 (111 patients) - Implantation of AspireAssist device
  • Group 2 (60 patients) - No implantation (control group)
  • All patients received diet and exercise counseling once a month for 12 months
Primary outcome: 1. Percent excess weight loss (%EWL) at 52 weeks 2. Percent of patients who lost ≥ 25% of EWL at 52 weeks. Percent excess weight loss = Weight loss/(actual body weight - body weight if BMI was 25) X 100.
Results

Duration: 52 weeks
Outcome AspireAssist Control Comparisons
Percent excess weight loss 32% 10% diff 21.7%, 95%CI [15% to 28%], p=0.0083
Percent losing ≥ 25% of EWL 57% 22% diff 34%, p<0.05
Percent of total body weight lost 12.1% 3.6% diff 8.6%, 95%CI [6.2% to 10.9%]
Average weight loss 30 lbs 9 lbs diff 21.6 lbs, 95%CI [16 to 27]
Study discontinuations 26% 48% N/A
  • Adverse events in the AspireAssist device group occurring in ≥ 5% of subjects: Peristomal granulation tissue (41%), abdominal pain ≤ 4 weeks after placement (38%), nausea/vomiting (18%), peristomal irritation (17%), intermittent abdominal discomfort (16%), peristomal infection (14%), abdominal pain > 4 weeks after placement (8%), dyspepsia (6%), peristomal inflammation (5%)
  • One participant had to have his tube replaced and one participant developed peritonitis after the procedure [39]






ReCharge Study - Vagal Nerve Blockade vs Sham Device for Weight Loss, JAMA (2014) [PubMed abstract]
  • The ReCharge study enrolled 239 obese patients
Main inclusion criteria
  • BMI 40 - 45, or BMI 35 - 39 with ≥ 1 obesity-related condition (hypertension, diabetes, dyslipidemia, sleep apnea, cardiomyopathy)
Main exclusion criteria
  • History of bariatric surgery
  • Hiatal hernia (> 5 cm)
  • History of inflammatory bowel disease
  • Medications for weight loss within 3 months
  • Chronic treatment with narcotic analgesics
Baseline characteristics
  • Average age 47 years
  • Female sex - 84%
  • Average BMI - 41
  • Average weight - 251 lbs (114 kg)
Patients were randomized in a 2:1 ratio to one of two groups:
  • Group 1 (162 patients) - Vagal nerve blockade device + weight management program
  • Group 2 (77 patients) - Sham device + weight management program
  • Patients in Group 2 had the device implanted, but it was not able to function
  • In Group 1, the device delivered a charge for at least 12 hours a day. The charge was increased via a protocol to a desired charge, depending on patient tolerance. The device was recharged at least twice a week for 30 - 90 minute intervals.
Primary outcome: Coprimary efficacy objectives were to determine whether the vagal nerve block was superior in mean percentage excess weight loss to sham by a 10-point margin with at least 55% of patients in the vagal block group achieving a 20% loss and 45% achieving a 25% loss. Percent excess weight loss = Weight loss/(actual body weight - body weight if BMI was 25) X 100
Results

Duration: 12 months
Outcome Vagal nerve blockade Sham Comparisons
Percent excess weight loss 24.4% 15.9% diff 8.5%, 95%CI [3.1 - 13.9]
Percent of actual body weight lost 9.2% 6% diff 3.2%, 95%CI [1.1 - 5.2]
Heartburn 23% 4% N/A
Pain, other 23% 0% N/A
Abdominal pain 12% 3% N/A
Dysphagia 8% 0% N/A
Burping 8% 0% N/A
Nausea 7% 1% N/A
Chest pain 6% 3% N/A
  • The prespecified primary objective was not met because the device did not achieve a 10% greater loss of excess weight
  • Three patients in the vagal nerve blockade group required another surgical procedure because of device issues

Findings: Among patients with morbid obesity, the use of vagal nerve block therapy compared with a sham control device did not meet either of the prespecified coprimary efficacy objectives, although weight loss in the vagal block group was statistically greater than in the sham device group. The treatment was well tolerated, having met the primary safety objective.