Editor's note: This is the third in a series of summaries of nursing care–related systematic reviews from the Cochrane Library.
What are the effects of bariatric surgery on weight, comorbidities, and quality of life?
TYPE OF REVIEW
This is a Cochrane systematic review without meta-analysis.
RELEVANCE FOR NURSING
Obesity is associated with many health problems and a higher risk of death. Weight loss surgery for obesity is usually considered only when other treatments have failed. Bariatric surgery aims to reduce weight and maintain any loss through restriction or malabsorption of food, or a combination of these. A number of different bariatric procedures are available, and these can be performed as either open (traditional) or laparoscopic (keyhole) surgeries. Gastric bypass and adjustable gastric banding are the most commonly performed surgical interventions for obesity; however they pose a risk of significant early or late morbidity and of perioperative mortality. In addition, patients need to adjust to major lifestyle changes after surgery. Nursing care can make a significant contribution to positive outcomes in these patients.
CHARACTERISTICS OF THE EVIDENCE
Twenty-six studies were included in the review. Three randomized, controlled trials (RCTs) and three prospective cohort studies compared surgery with conventional management (medical management or no treatment), and 20 RCTs compared different bariatric procedures. The cohort studies were of variable sample sizes and quality. The majority of participants, most of whom were women between the ages of 32 and 49, were described as morbidly obese. The minimum follow-up for inclusion in this review was 12 months; most studies followed participants for 12, 24, or 36 months.
The review found that surgery resulted in greater weight loss than conventional treatment in people whose body mass index (BMI) was greater than 30, as well as in those with more severe obesity. Surgery also resulted in some improvements in quality of life and obesity-related diseases, such as hypertension and diabetes. However, surgery was associated with complications such as pulmonary embolism, and postoperative deaths did occur (101 or 5% of 2,010 surgery patients compared with 129 or 6.3% of 2,037 control patients).
Five different bariatric procedures were assessed, but in some cases procedures were compared in only one trial. The limited evidence suggests that weight loss following gastric bypass is greater than that achieved after vertical banded gastroplasty or adjustable gastric banding but is similar to the weight loss achieved with isolated sleeve gastrectomy and banded gastric bypass. Isolated sleeve gastrectomy appears to result in greater weight loss than adjustable gastric banding.
No trial results reached any conclusion about the relative safety of these procedures.
Weight loss and quality of life were similar between open and laparoscopic surgery. Recovery was often quicker following laparoscopic surgery, with fewer wound problems, although some studies found more reoperations were needed.
BEST PRACTICE RECOMMENDATIONS
Surgery is more effective than conventional management in treating obesity; however it's associated with adverse effects and the possibility of postoperative mortality. Due to limited evidence and poor trial quality, caution is required when interpreting the comparative safety and effectiveness of these procedures.
There is a need for high-quality, long-term RCTs that compare different operative techniques for treating obesity and that incorporate an assessment of patient quality of life. RCTs that measure the clinical effectiveness of bariatric surgery in adults with Class I (BMI of 30 or greater but less than 35) or Class II obesity (BMI of 35 or greater but less than 40) and young people with obesity are also needed.