An Internist’s Guide to the Post-Bariatric Surgery Patient

Dan Bessesen, MDChief of Endocrinology; Denver Health

Medical CenterDaniel.bessesen@uchsc.edu

Learning Objectives

• List the differences between the Lap Band and the Roux en Y Gastric Bypass in: weight loss, risks and complications.

• Describe an approach to managing obesity related co-morbidities in the post-bariatric surgical patient.

• List the common nutritional and metabolic complications that occur following bariatric surgery and describe an approach to managing these.

• Name the most recent guidelines for the management of the post-bariatric surgical patient.

Bariatric Surgery

• Review procedures: gastric bypass and laparoscopic banding

• Describe the management of co-morbidities in the immediate post operative period

• Describe the prevention and treatment of common nutritional deficiencies

• Discuss a number of Cases

Gastric Bypass

Lap Band

Lap Band

0

10000

20000

30000

40000

50000

60000

70000

80000

90000

100000

110000

'92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03

Increased Demand for Bariatric SurgeryIncreased Demand for Bariatric Surgery100,000+100,000+

Num

ber

of o

pera

tions

NEJM, 2004;350:1076

Year

205,000 procedures in 2007 205,000 procedures in 2007

16,00016,000

Long-term Weight Loss After Gastric Bypass in 608 Morbidly Obese Patients

Long-term Weight Loss After Gastric Bypass in 608 Morbidly Obese Patients

Pories WJ et al. Ann Surg. 1995;222:339-350.

Mean Wt BMI(lb) (kg/m2)

Preop 304.4 49.71 yr 192.2 31.55 yr 205.4 33.714 yr 204.7 34.9

Mean Wt BMI(lb) (kg/m2)

Preop 304.4 49.71 yr 192.2 31.55 yr 205.4 33.714 yr 204.7 34.9

Wei

ght

(lb)

Years

100

150

200

250

300

350

0 0.5 2 4 6 8 10 12 14

Sjostrom L NEJM 2007: 357-741-752

Weight Loss in the SOS Study

Vertical, BandedGastroplasty

Bariatric Surgery is Associated with aReduced Mortality: the SOS Study

Sjostrom L NEJM 2007: 357-741-752

AdjustedRisk Patio=0.71P=0.01

MI: 25 in controlGroup 13 in theSurgery group

Cancer: 47 inThe control group29 in the surgerygroup

Long Term Mortality is Reduced After Gastric Bypass Surgery

Adams TD, NEJM 2007; 357:753-61

• Retrospective cohort study of 7925 individuals who had GBPS compared to 7925 obese control subjects identified from driver’s license records in Utah matched for age, sex and BMI.

• Rates of death over 7.1 years of follow up were determined from National Death Index.

• Adjusted mortality was 40% lower in the surgically treated group (37.6 vs 57.1 deaths per 10,000 person years, p,.001)

Adjustable Gastric Banding and Conventional Therapy for Type 2

DiabetesDixon JB, JAMA, 2008; 299: 316-23

• Previous studies had shown that diabetes frequently resolves following bariatric surgery.

• This group had done a previous randomized trial in Metabolic Syndrome.

• This was a randomized trial of lap banding versus conventional therapy in 60 subjects with diabetes for <2 years and a BMI between 30-40 kg/m2

• This is an outstanding group with outstanding results, so results may not be universally applicable.

Effects of Bariatric Surgery on Weight and Diabetes Status

Adams TD, NEJM 2007; 357:753-61

73% remission of diabetes in the surgery Group versus 13% in the control group

Benefits

• Weight loss roughly – 30% (50-60% of excess weight) with GBPS

Maintained for >15 yrs– Lap band: 20-25% less risk

• Sleep apnea: Improved in almost all• Hypertension: improved in half• Gastroesophageal reflux: improved in most• Urinary incontinence: improved in most

Annals of Surgery 237:751-758,2003 Sugarman

Risks of Bariatric Surgery

• Bypass: Death 0.5% (0-2%) (within 30 days) Late Death (1-3%) (within 2 years)

• Lap Band: 0.1% death rate• Failure of the Surgery to Produce Weight Loss

(10-15%)• Pulmonary embolus• Anastamotic leaks/Sepsis• Wound problems: infections, dehiscence • Anastamotic Stricture: dilate or re-operate

Bariatric Surgical Guidelines

• American Association of Clinical Endocrinologists/the Obesity Society/ American Society for Metabolic and Bariatric Surgery 2008

• www.aace.com/pub/guidelines/• Evidence based A-D recommendations• 164 recommendations• 777 references• 83 pages long

Importance of Aftercare

• Surgery is only the beginning• Initially the “full time job” is learning to

eat• Team approach to follow up: you are an

important player• Primary goal is to maintain good

nutrition• “Keep folks on the road”

Managing Co-Morbidities

• Diabetes: immediately after surgery– Stop sulfonylureas, cut other meds in half– SMBG to adjust further

• Hypertension: immediately after surgery– Stop diuretics

• Arthritis– Stop NSAIDS 10 days pre-op– avoid for 6-12 months

• OSA: CPAP mask and pressure may need adjustment

• GERD, Urinary incontinence, hyperlipidemia

Dietary Issues

• Eat slowly: 30 minutes to eat 2-3 oz.

• Small amounts: ½-1 cup, 2-3 oz at a time

• Protein containing foods: 60 g/d

• Avoid calorie dense foods

• Avoid sugar containing foods

Micronutrient Deficiencies

• Primarily an issue with RYGB (Lap band can get thiamine deficiency)

• Predictable based on the bypassed segments

• Preventable with appropriate monitoring and supplementation

• Fe, Ca, B12, Vitamin D, Folate, Thiamine

Thiamine

• Without supplementation, can become acutely deficient in the post-operative period especially if lots of vomiting.

• Sx: Double vision, ataxia, nystagmus, facial weakness, polyneuropathy, confusion, Wernicke’s encephalopathy

• Beriberi– Dry: symmetric peripheral polyneuropathy– Wet: high output CHF

• Rx: 100 mg IV or IM daily x 7-14 days, the 10 mg/d orally till recovery

Iron

• Causes– Decreased meat intake– Achlorhidria– Bypass site of absorption– Decreased absorption

• Particularly a problem in menstruating women

• May present with pica/pagophagia

Iron

• Goal is to pick up early with monitoring.• Most sensitive test is ferritin.• To prevent all pt should be on MVI.

– Prenatal MVI has increased Fe and Folate.

• If deficiency develops try oral replacement.• 20-30% may need parenteral replacement

(Ferrlecit, INFed, Jenofer etc).

B12

• Causes– Low intake of meat and dairy– Poor digestion of meats resulting in decreased

release of cobalamins from food– Low acid– Low intrinsic factor

• Deficiency develops in 30% at 1 year, and 50% by 5 years if not supplemented

• Monitoring: B12 level (homocysteine, MMA)

B12

• Prevention: RDI about 1 mcg/d– Oral crystaline B12: 500-1000 mcg/d– Sublingual 500 mcg/d– Nasal spray (Nascobal): 500 mcg/wk – IM: 100 mcg/mo

Calcium/Vitamin D

• Decreased intake of Ca and D containing foods.

• Malabsorption of both calcium and D due to bypassed segments.

• Results in secondary hyper-parathyroidism and over the long run osteoporosis.

• Prevention is the best approach.

Calcium/Vitamin D

• 25OH D deficiency is very common– Obesity– Dark skinned people– Level 20-30 ng/ml is LLN– Present pre-operatively in 30-40%

• Replace pre-operatively if deficient– 50,000 u weekly x 2 months

Calcium/Vitamin D

• Post-operatively– Ca citrate 1200-1500 mg/d (has 400 u D)– Prenatal MVI: 400-800 u/d D– Monitor 25OH D level every 3 months

• May reduce Ca supplement if person is tolerating and eating a lot of dairy.

• Consider DEXA at 1-2 years post-op and every 2 years after.

Summary Nutritional Issues

• Supplement: – MVI daily– B12 500-1000 mcg daily orally– Ca 1200-1500 mg/d

• Monitoring: – Fe, TIBC, Ferritin– B12– Folate– 25OH D, PTH, DEXA

Pregnancy

• Fertility increases following weight loss.• Avoid getting pregnant for the first year after

surgery: BCP or other effective contraception.• Pregnancies need to be monitored, but

outcomes appear good• Lap band: May need adjustment if pregnant• Vitamins, micronutrients critical

Case 1

• 48 year old woman had RYGB surg 16 years ago. Peak wt pre-operatively was 380 lbs. She lost 140 lbs and did well for 7 years but then developed a stricture which was dilated. Since then she has gradually gained weight and developed diabetes.

• Why did she regain the weight?• What tests do you want to do?

Roux-en-YGastric Bypass

Case 1

• Failure to maintain weight loss can occur, but this surgery worked initially.

• Old procedure left pouch and stomach in continuity and dilation procedure could have broken down this anastamotic line.

• Test: UGI• If there is an anastamotic failure then a re-

operation may restore weight loss.

Case 2

• 52 year old man had RYGB surg 3 years ago. He has lost 30% of his baseline weight and was feeling well until a couple of months ago when he had spells of sweating, cloudy thinking, light headedness, tremor and sweating. Yesterday he had a seizure and the EMTs found his glucose to be 15 mg/dl.

• What is the diagnosis?• What tests do you want to do?• How can you treat this?

Case 2

• Neisidioblastosis: beta-cell proliferation causing hyperinsulinemic hypoglycemia.

• Typically occurs years after RYGB surgery.• Hypoglycemia is post-prandial.• Can do an OGTT and check insulin and C-

peptide if becomes hypoglycemic.• Advise carb restriction, mixed meals, lente

carbohydrates like corn starch.• May need partial pancreatectomy.

Case 3

• 38 year old man had RYGB surg 4 months ago. He has lost 20% of his baseline weight and was feeling well until a week ago. He comes to the office complaining of 5 episodes of nausea and vomiting over the last 3 days.

• What is the differential diagnosis?• What tests do you want to do?• How can you treat this?

Case 3

• DDX: anastamotic stricture, anastamotic ulcer or dietary indiscretion.

• Hx should focus on dietary patterns around the onset of the nausea. Hx of pain, hematemesis, melena

• Likely needs UGI/endoscopy or both.

Case 4

• 33 year old woman had lap band surg 1 year ago. She lost 10% of her baseline weight and was frustrated with the surgical team She comes to the office for ongoing management of her hypertension.

• Why didn’t she lose more weight? • Do you have any thoughts about how you

might help her lose more weight?

Case 4• The weight loss after Lap Band is much more

dependent on follow up and band adjustment.

• Even so, some people do not lose that much weight.

• Failure to lose may represent mechanical failure

• Options include:– Evaluate the integrity of the device

– Greater focus on her diet

– Return for an adjustment

– Pharmacotherapy

– Revision of the operation to a RYGB

Other issues

• Depression– Many expect things to get better post-op– Pre-existing depression exacerbated by stress of

surgery– Suicides increased post operatively in some series – Ask about mood post-op

• Too much weight loss too fast. – Look for signs of volume depletion– Puts at risk for infection

Summary for Surgical Studies

• Bariatric surgery has increasingly been shown to have dramatic health benefits.

• There has been a shift from open gastric bypass procedures to laparoscopic procedures, with more lap bands being done due to lower risk.

• Effectiveness and safety are clearly related to the experience and volume of the surgical group.

Bariatric Surgery ResourcesBariatric Surgery ResourcesAmerican Society for Bariatric Surgerywww.asbs.org

International Bariatric Surgery Registry (IBSR)www.surgery.uiowa.edu/ibsr

International Federation for the Surgery of Obesity www.obesity-online.com/ifso

Betsy Lehman Center for Patient Safety and Medical Error Reduction: Expert Panel on Weight Loss Surgerywww.mass.gov/dph/betsylehman/index.htm