What is the efficacy of bariatric surgery?

Updated: Feb 16, 2021
  • Author: Alan A Saber, MD, MS, FACS, FASMBS; Chief Editor: John Geibel, MD, MSc, DSc, AGAF  more...
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The Swedish Obese Subjects (SOS) study is an ongoing, prospective study of 2010 obese participants who underwent bariatric surgery and 2037 obese patients who received usual care in the primary health care system. Compared to the control group, obese adults who underwent surgery experienced a reduced number of cardiovascular deaths and a lower incidence of heart attack and stroke. [1, 2]  A 2017 report from the SOS group found that bariatric surgery reduced the long-term incidence of female-specific cancer, particularly endometrial cancer. [3]

Low back pain is a common complaint among obese patients. A retrospective study of morbidly obese patients who underwent bariatric surgery found that patients experienced a significant decrease in low back and radicular pain after surgery, which led to improvements in quality of life. Patients also experienced a marked increase in the L4-5 intervertebral disc height. [4]

An Australian study by Keating et al compared the results of weight-loss treatments in patients who had been diagnosed with type 2 diabetes mellitus in class I/II obesity, estimating the lifetime costs and quality-adjusted life-years (QALYs) for individuals who had undergone surgically induced weight loss and for patients who had utilized conventional weight loss treatment. [5]

In this study, the mean duration of diabetes remission over a lifetime was 11.4 years in the surgical therapy group and 2.1 years in the conventional therapy group. [5] Over the remainder of their lifetime, surgical therapy patients lived 15.7 discounted QALYs, compared with 14.5 discounted QALYs for conventional therapy patients. Mean discounted lifetime costs were AUD $98,900 per surgical therapy patient and AUD $101,400 per conventional therapy patient (AUD $1 = USD $0.74). Compared with conventional therapy, surgical therapy yielded a mean healthcare saving of AUD $2400 and 1.2 additional QALYs per patient.

In another study, Keating et al looked at the within-trial cost efficacy, over 2 years, of surgical treatment relative to that of conventional therapy for achieving remission in patients recently diagnosed with type 2 diabetes mellitus with class I/II obesity. [6]  Trial intervention costs included gastric banding surgery, mitigation of complications, outpatient medical consultations, medical investigations, pathology, weight-loss therapies, and medication.

An incremental cost-effectiveness analysis demonstrated that the mean 2-year intervention costs per patient were Au $13,400 for surgical therapy and Au $3400 for conventional therapy; laparoscopic adjustable gastric band (LAGB) surgery was responsible for 85% of the difference. [6] For surgical patients, outpatient medical consultation costs were threefold greater than those for conventional patients, but medication costs were 1.5 times higher for patients who underwent conventional therapy. The cost differences occurred primarily in the trial's first 6 months. In relation to conventional treatment, the incremental cost-effectiveness ratio for surgical therapy was Au $16,600 per case of diabetes remitted.

An updated Cochrane review from 2014 that included 22 trials with 1798 participants concluded that surgical treatment of obesity yielded greater improvement in weight loss and weight-associated comorbidities than nonsurgical interventions did, regardless of the type of procedure, [7]  though certain procedures were associated with greater weight loss and fewer comorbidities than others.

In this review, Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy had comparable outcomes, and both had better outcomes than adjustable gastric banding. [7]  In very-high-BMI patients, biliopancreatic diversion with duodenal switch yielded better weight loss than RYGB did. Outcomes were comparable for duodenojejunal bypass with sleeve gastrectomy and laparoscopic RYGB. Isolated sleeve gastrectomy led to better weight loss than adjustable gastric banding. Weight-related outcomes were similar for laparoscopic gastric imbrication and laparoscopic sleeve gastrectomy.

In general, with all 22 studies taken into account, rates of adverse events and reoperation were not well reported. [7]  Because the follow-up period in most of the trials reviewed was only 1 or 2 years, the long-term effects of bariatric surgery could not be definitively established.

A study by Jakobsen et al assessed obesity-related comorbidities in 1888 severely obese patients undergoing either bariatric surgery (n = 932; 92 gastric bypass) or specialized medical treatment (n = 956). [8]  Median follow-up was 6.5 years (range, 0.2-10.1 years). Surgical patients were more likely to experience remission and diabetes remission and were less likely to experience new-onset hypertension; however, they also had a greater risk of new-onset depression and treatment with opioids and were more likely to undergo at least one additional GI surgical procedure.

Ikramuddin et al evaluated lifestyle intervention and medical management with (n = 60) and without RYGB (n = 60) for achieving control of type 2 diabetes (composite triple end point: HbA1c < 7.0%, LDL cholesterol < 100 mg/dL, systolic blood pressure < 130 mm Hg). [9]  Of the 120 patients, 98 completed 5-year follow-up. At 5 years, there remained a significantly better composite triple end point in the surgical group; however, the effect size diminished over 5 years, indicating the need for further follow-up to better define the durability of the improvement.

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