Bariatric Surgery: Bypass, Band, or Sleeve at 2 Years

As the number of bariatric surgeries increase, clinicians require more and better data about its long-term outcomes. As we know, as more people take a medication or undergo a surgical procedure, the better the quality of the collective data. It’s the strength in numbers concept. In the case of bariatric surgery, many clinicians have questions about treatment failure rates and they suspect that reports of sustained weight loss may be overly optimistic.

A meta-analysis published in the September 2014 issue of JAMA starts to answer questions about long-term outcomes of various bariatric procedures. For the purposes of this analysis, the researchers defined long-term outcome as status at 2 years post-procedure.

These researchers were interested in four outcomes for which severely obese adults generally undergo these procedures: weight loss, type 2 diabetes, hypertension, and hyperlipidemia. Their search for studies was comprehensive, as they started with Cochrane reviews published from 1946 and explored publications through May 15, 2014. They identified 7,371 clinical studies that reported outcomes at 2 years and ultimately eliminated all but 29 studies (16% of the total). These studies included a total of 7,971 patients.

Approximately 1/3 of patients who had gastric band procedures lost more than 50% of their body weight and sustained the loss for 2 years. On average, gastric bypass patients lost 65.7% of their body weight, compared to 45% for patients who had gastric band surgeries.

Evidence for long-term outcomes for gastric sleeve resections is insufficient to draw any conclusion.

Gastric bypass resulted in better medical outcomes than gastric band on all measures:

• For type 2 diabetes, 66.7% of gastric bypass patients achieved a HbA1c <6.5% without medication compared to 28.6% for gastric band patients.
• More patients in the gastric bypass group—38.2%&mdash;experienced hypertension remission (blood pressure <140/90 mmHg without medication) compared to 17.4% in the gastric band studies.
• For hyperlipidemia, remission rates (cholesterol <200mg/dL, high-density lipoprotein >40 mg/dL, low-density lipoprotein <160mg/dL, and triglycerides <200mg/dL) were 60.4% for gastric bypass and 22.7% for gastric band.
• Long term mortality and morbidity were low (less than 2%).

The authors conclude that gastric bypass has better outcomes than gastric band procedures for long-term weight loss, type 2 diabetes control and remission, hypertension, and hyperlipidemia. Future studies need to make sustained efforts to follow patients for at least 2 years, since drop-out rates of greater than 20% skew data.