The Medical Complications of
Bariatric Surgery
Jeanette Newton Keith MD
Associate Professor
University of Alabama at Birmingham
Department of Nutrition Sciences
Department of Internal Medicine
(www.eatright.uab.edu)
Background

More than one million people are classified as
morbidly obese in the United States

Bariatric surgery has emerged as a definitive
therapy for long-term treatment of obesity

The three to five year success rate is 54-75% for
surgery versus a 6-8% three-year success rate with
medical weight management programs
Background

Between 1990 to 1997, 12,203 people underwent bariatric
surgery

The annual rate has increased from 2.7 per 100,000 people
(1990) to 6.3 per 100,000 people (1997)

In 2006, approximately 177,600 cases were performed per
the American Society for Bariatric Surgery

Some estimate that > 205,000 surgeries will be performed
this year (Source: American Society for Metabolic and
Bariatric Surgery)
“To Cut or Not To Cut”

Medical Therapy 5-10% excess weight loss

Pharmacologic Intervention 8-10% EWL

Bariatric Surgery
60-80% EWL
Bariatric Surgery
 Indications
for Bariatric Surgery:
Failure of medical therapy-3-5 yr attempt
Life-threatening complications of obesity
Severe obesity
(BMI >40 or >35 with complications)
 Monitoring
pre-surgery:
Minimum of 6 months medical therapy
Followed by MD, DO or FNP
∆Wt, Food logs, exercise, psych
Blue Cross Blue Sheild of IL
Types of Bariatric Procedures
Malabsorptive:
Jejuno-ileal bypass
Biliopancreatic Diversion
Duodenal Switch (DS), no bypass
 Restrictive:
Vertical banded gastric bypass
Laproscopic adjustable gastric banding
 Restrictive and Malabsorptive:
Roux-en Y gastric bypass
Distal gastric bypass with DS

Surgical Advantages of Pure Gastric
Restriction

50% excess weight loss at 1 year

Minimal nutrition complications

Can be used in populations that are high
risk for RYGB
Surgical Advantages of Combined
Gastric Restriction & Malabsorption
 Advantages of Gastric Bypass:
60% of excess weight lost in year 1
Maintains a weight loss of 50% for 25 years
Rapid resolution of metabolic syndrome
Improvement in obesity-related complications
 Advantages of the Duodenal Switch:
60-80% of excess weight lost in year 1
Most effective therapy for super obese
Combined Gastric Restriction &
Malabsorption

Operative Risks: (vs. cholecystectomy)
Perioperative Mortality
Early Complications
Late Complications

1-2% vs. 0.2-0.8%
10% vs. 2.9%
20% vs. 1-2%
Limitations:
Widening of (unbanded) gastrojejunostomy
Expansion of gastric pouch
25% with nearly 100% weight regain***
Adaptation of limb that receives the food
Combined gastric restriction &
malabsorption

Potential complications:
1) severe dumping syndrome - rapid rush
of liquid/soft high caloric food “dumping”
into limb of small intestine….discomfort,
nausea, bloating, diarrhea, weakness
2) Abnormalities in iron, calcium, B12,
and possibly magnesium homeostasis
3) Profound rapid weight loss
Weight Loss Benefits vs. Nutritional
Risk
70
60
50
40
EWL
Mortality
B12 def
30
20
10
0
Band
Gastroplasty
GBP
DS
Risk of Deficiencies

Determined by the type of surgical intervention
 Restrictive
Minimal risk
 Malabsorptive
Moderate risk
 Combination
High risk

Risk increases as:
 the length of the common channel decreases, and
 the degree of malabsorption increases
Risk of deficiencies
Deficiency
RYGBP
DS
Protein
4.7%
3-5%
Calcium
15-43%
Iron
Ferritin
33-50% 1 yr
49-52% 3yr
44-50%
15-57% 1 yr
63% 4 yr
35-74% 3 yr
Albumin
2%
2%
Anemia
35-74% 5 yr
35-74% 5 yr
44-50%
Risk of deficiencies
Deficiency
RYGBP
DS
B12
12-33%
33%
Thiamine
“Common”
“Common”
Folate
12%
12%
Vitamins A and “Frequent”
E
Vitamin D
>30%
A- 69% E-4%
K- 68%
30 -63%
Zinc
“Frequent”
“Frequent”
Other Nutrition Complications

Refractory Hypoglycemia

Vitamin C Deficiency

Selenium deficiency

Copper deficiency
Other Nutrition Complications

Severe Protein Calorie Malnutrition

Functional Pancreatic Insufficiency

Accelerated Weight Loss

Hepatic Failure

Dehydration
Other Post-surgical Complications

Anastomotic leak or bleeding (1-2%)

Strictures (10-15%)

Fistula formation

Severe diarrhea

Intusseption
Other Post-surgical Complications

Short Bowel Syndrome

Abdominal pain

Intestinal ischemia

Gastric erosions or ulceration

Hernias- Hiatal, Incisional
Non-Nutritional Psychosocial
Complications

Depression

Suicide

Alcoholism

Night Eating Syndrome

Binge Eating Syndrome
Zwaan et al Int J Eat Disord 2006
Adams et al NEJM 2007
Hsu et al Psychosom Med 1998
Types of Bariatric Procedures
Malabsorptive:
Jejuno-ileal bypass
Biliopancreatic Diversion
Duodenal Switch (DS), no bypass
 Restrictive:
Vertical banded gastric bypass
Laproscopic adjustable gastric banding
 Restrictive and Malabsorptive:
Roux-en Y gastric bypass
Distal gastric bypass with DS

Laproscopic Adjustable Banding

Nutritional Deficiencies:
Protein

Endoscopic limits:
Depends on lumen
Retroflexion

Increased risk of
ischemia and necrosis
Roux-en Y Gastric Bypass


Nutritional deficiencies:
Vitamin B12
Calcium
Iron
Protein
Endoscopic limits:
Retroflexion
ERCP
Distal Roux-en Y Gastric BP

Nutritional deficiencies:
Vitamin B12Calcium
Iron
Protein

Endoscopic limits:
Retroflexion
ERCP
Duodenal Switch, with RYGB

Pylorus and D1-sparing

Nutritional deficiencies:
Protein
Magnesium
Vitamin B12
Iron
Calcium

Endoscopic limits:
ERCP
Anti-obesity Surgery and Co-morbidities
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J Kral 1995, >1000 patients
Suggested Monitoring
Monitoring Guidelines

Frequent (no less than every 3 months)
 Weight (more often in first 6 months)
 CBC, Electrolytes, BUN, Cr, Ca, Mg, P
 Glucose, Liver Tests, Albumin
 Fat soluble vitamins-A,D.E and K
 Vitamin B12, B1
 Iron studies
 Vitamin C, Selenium, Zinc, Copper
 Pre-albumin (or Transferrin if renal disease)
Suggested Monitoring

Occasional (at least annually)
 Measured Height
 Bone Mineral Density
 PTH, 1,25-OH Vitamin D, Zinc, 24 hour
urine calcium
Post Surgical Monitoring

Weight loss progression*
st
 Goal: not more than 1-2 lbs/d in 1 mo

Adequate Protein Intake

Fluid status
Presutti et al, Mayo Clin Proc 2004
Goal Nutrient Intake

Protein
(1-2 grams per kg of adjusted weight)
 60 gram Gastric bypass
 75 grams Duodenal Switch

Fat
 25% total calories

Carbohydrate
 15-30 grams per serving day in 4-6 servings

Fluid
 64 ounces
Potential Nutritional Limitations

Meat and dairy intolerance

Nutrient malabsorption

Vomiting, especially with over-consumption

Constipation

Dehydration
Dolan, Ann Surg 2004
Elliott Crit Care Nurs Q 2003
Post-surgical Supplementation
Prenatal multivitamin or Flintstone
chewable MVI with minerals (2/day)
 Iron Polysaccharide 150 mg po BID for
women
 Calcium Carbonate 500 mg po TID
 Vitamin D 400 IU po qD
 Vitamin B12 500 mcg po qD

Forse et al, Current Opin Endo Diabete 2000
Alvarez-Leite, Current Opin Clin Metab Care 2004
Nutrient Deficiencies

Preventable with supplementation

Require lifelong compliance with
supplements

Minimized by regular and routine
monitoring
Nutrition Monitoring Challenges

Few randomized protocols to address nutrition
monitoring

How often and for how long patients are to be
followed is debated due to $$$

Timing of follow-up visits not clear

Routine vitamin replacement not covered by
many carriers
Take Home

Bariatric surgery can be life-saving for the
right patient

Attention to adequate nutrition and vitamin
supplementation is key

Lifelong monitoring is essential