Obesity Surgery : Is it only for losing weight ?

Joint Hospital Surgical Grand RoundSimon Chu

Prince of Wales Hospital

Obesity Classification

WHO

Class Asian

Underweight < 18.5

Normal 18.8 – 22.9

Overweight >23

Obese I >25

Obese II >30

Obese III N/a

WHO guidelines 2005

Figures in Hong Kong

Burden of Obesity – lessons learnt from Hong Kong Chinese Obesity Reviews (2008) 9 (Suppl. 1,) 35-40

Gastric Banding• Reversibility• Ability to calibrate • Less destructive to

stomach

Sleeve Gastrectomy

• Preserve normal food passage

• Second stage procedure is possible

• Serious complications

Gastric Bypass

• Most common procedures performed in U.S.

• Better long term outcome than pure gastric restrictive technique

• Persistent nutritional problems

Biliopancreatic diversion with duodenal switch

• Achieved best weight loss

• Possible for 2-stage procedure

• High operative complications

Intragastric balloon

• Artificial bezoar• Increase in satiety

reduction of food intake• Part of a diet programme• Temporary procedure to

aid further conventional intervention

• 1st element of assessing the efficacy of an bariatric surgery• Where is the evidence of GOOD WEIGHT REDUCTION = IMPROVEMENT OF CO-

MORBIDITIES

Meta-analysis : Surgical treatment of Obesity Ann Intern Med 2005; 142 : 547-559

• Swedish Obese Subjects (SOS)

• Prospective non-randomized, interventional trial

• Patients undergo bariatric surgery vs conventionally treated patients

• Effects of weight loss on risk factors and hard end points

• Changes in cardiovascular risk factors over follow-up periods

• Bariatric Surgery is a viable option for treatment of severe obesity as

1. Result in long term weight loss

2. Amelioration in risk factors

• Another prospective study using the same group of patients published in 2007

• To determine association between weight loss and mortality rate

• Study period : 10.9 years

• Weight loss from baseline : at least more than 15%

• Adjusted hazard ratio 0.76 surgery group

New England Journal Of Medicine Vol 347, No 8 Aug 23, 2007

Apart from weight reduction…..

Apart from weight reduction

Circulation 2004; 110 : 1245-1250

• Asia patients :

Abdominal obesity Men : 90cm Women : 80cm

Any help?• Significant improvement in all parameters after gastric

bypass surgery at post-operative 6 months Remission of Metabolic Syndrome : A study of 140 patients Six Months after Roux-en-Y Gastric Bypass

Obesity Surgery ( 2008 ) 18: 601-606

• Gastric Bypass Surgery induces persistent and considerable improvement in MetS prevalence compared with patients treated conventionally

Effect of Bariatric Surgery on the Metabolic Syndrome : A population based, Long-term Controlled Study

Mayo Clinic Proceedings : Aug 2008 : 83, 8

JAMA 2008; 299 (3) : 316-323

• Unblinded randomized controlled trial• 60 patients with BMI between 30 and 40 and recently diagnosed type 2 DM• Conventional diabetes therapy vs laparoscopic adjustable gastric banding• Outcomes : Remission of type 2 diabetes ( Fasting glucose < 7 mmol/L and HbA1c < 6.2% while not on glycemic

therapy )

Diabetic Remission : 22/30 (73%) in surgical group 4/30 (13%) in conventional group at 2 years

The Future..

Metabolic Surgery

• Return to euglycaemia and normal insulin levels are observed within days after bypass surgery

• Weight loss alone cannot explain the association

• “ Rearrangement of gastrointestinal anatomy as a primary mediator of surgical control of diabetes ?“

Open questions for clinical Research

• Surgical treatment for Diabetes in patients

1. BMI < 30 ?

2. Or with normal BMI ?

Conclusion• Bariatric Surgery is effective in promoting weight loss in

morbid obesity which has a long lasting effect

• Effect of weight loss can be transferred to reduction in mortality rate

• Apart from weight loss, remission of metabolic syndrome and type 2 diabetes are the other clinical outcomes associated with bariatric surgery