Applied Evidence

Obesity: When to consider surgery

J Fam Pract. 2018 October;67(10):614-616,618-620

References

1. Must A, Spadano J, Coakley EH, et al. The disease burden associated with overweight and obesity. JAMA. 1999;282:1523-1529.

2. Wing RR, Lang W, Wadden TA, et al. Benefits of modest weight loss in improving cardiovascular risk factors in overweight and obese individuals with type 2 diabetes. Diabetes Care. 2011;34:1481-1486.

3. Magkos F, Fraterrigo G, Yoshino J, et al. Effects of moderate and subsequent progressive weight loss on metabolic function and adipose tissue biology in humans with obesity. Cell Metab. 2016;23:591-601.

4. American Academy of Family Physicians. Clinical preventive service recommendation: Obesity. www.aafp.org/patient-care/clinical-recommendations/all/obesity.html. Accessed August 22, 2018.

5. American Academy of Family Physicians: USPSTF draft recommendation: Intensive behavioral interventions recommended for obesity. www.aafp.org/news/health-of-the-public/20180221uspstfobesity.html. Published February 21, 2018. Accessed August 22, 2018.

6. Saunders KH, Shukla AP, Igel LI, Aronne LJ. Obesity: When to consider medication. J Fam Pract. 2017;66:608-616.

7. Roux CW, Heneghan HM. Bariatric surgery for obesity. Med Clin North Am. 2018;102:165-182.

8. Sjöström L, Peltonen M, Jacobson P, et al. Bariatric surgery and long-term cardiovascular events. JAMA. 2012;307:56-65.

9. Sjöström L. Review of the key results from the Swedish Obese Subjects (SOS) trial - a prospective controlled intervention study of bariatric surgery. J Intern Med. 2013;273:219-234.

10. Reges O, Greenland P, Dicker D, et al. Association of bariatric surgery using laparoscopic banding, Roux-en-Y, gastric bypass, or laparoscopic sleeve gastrectomy vs usual care obesity management with all-cause mortality. JAMA. 2018;319:279-290.

11. Lee JH, Nguyen QN, Le QA. Comparative effectiveness of 3 bariatric surgery procedures: Roux-en-Y gastric bypass, laparoscopic adjustable gastric band, and sleeve gastrectomy. Surg Obes Relat Dis. 2016;12:997-1002.

12. American Society for Metabolic and Bariatric Surgery. Estimate of bariatric surgery numbers, 2011-2017. https://asmbs.org/resources/estimate-of-bariatric-surgery-numbers. Published June 2018. Accessed August 22, 2018.

13. Courcoulas AP, King WC, Belle SH, et al. Seven-year weight trajectories and health outcomes in the Longitudinal Assessment of Bariatric Surgery (LABS) Study. JAMA Surg. 2018;153:427-434.

14. Heymsfield SB, Wadden TA. Mechanisms, pathophysiology, and management of obesity. N Engl J Med. 2017;376:254-266.

15. Colquitt JL, Pickett K, Loveman E, Frampton GK. Surgery for weight loss in adults. Cochrane Database Syst Rev. 2014;(8):CD003641.

16. Jensen MD, Ryan DH, Apovian CM, et al; American College of Cardiology/American Heart Association Task Force on Practice Guidelines; Obesity Society. 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and The Obesity Society. Circulation. 2014;129:S102-S138.

17. Garvey WT, Mechanick JI, Brett EM, et al; Reviewers of the AACE/ACE Obesity Clinical Practice Guidelines. American Association of Clinical Endocrinologists and American College of Endocrinology clinical practice guidelines for comprehensive medical care of patients with obesity. Endocr Pract. 2016;22 Suppl 3:1-203.

18. Carlin Am, Zeni Tm, English WJ, et al; Michigan Bariatric Surgery Collaborative. The comparative effectiveness of sleeve gastrectomy, gastric bypass, and adjustable gastric banding procedures for the treatment of morbid obesity. Ann Surg. 2013;257:791-797.

19. Gill RS, Birch DW, Shi X, et al. Sleeve gastrectomy and type 2 diabetes mellitus: a systematic review. Surg Obes Relat Dis. 2010;6:707-713.

20. Karamanakos SN, Vagenas K, Kalfarentzos F, et al. Weight loss, appetite suppression, and changes in fasting and postprandial ghrelin and peptide-YY levels after Roux-en-Y gastric bypass and sleeve gastrectomy. Ann Surg. 2008;247:401-407.

21. Abdeen G, le Roux CW. Mechanism underlying the weight loss and complications of Roux-en-Y gastric bypass. Obes Surg. 2016;26:410-421.

22. Schauer PR, Bhatt DL, Kirwan JP et al; STAMPEDE Investigators. Bariatric surgery versus intensive medical therapy for diabetes - 5-year outcomes. N Engl J Med. 2017;376:641-651.

23. Aminian A, Brethauer SA, Andalib A, et al. Individualized metabolic surgery score: procedure selection based on diabetes severity. Ann Surg. 2017;266:4:650-657.

24. Smetana GW, Jones DB, Wee CC. Beyond the guidelines: Should this patient have weight loss surgery? Grand rounds discussion from Beth Israel Deaconess Medical Center. Ann Intern Med. 2017;166:808-817.

25. Wolfe BM, Morton JM. Weighing in on bariatric surgery: procedure use, readmission rates, and mortality [editorial]. JAMA. 2005;294:1960-1963.

How does the procedure work? RYGB constructs a small pouch from the proximal portion of the stomach and attaches it directly to the jejunum, thus bypassing part of the stomach and duodenum. The procedure is effective for weight loss because it is both restrictive and malabsorptive: patients not only eat smaller portions, but cannot absorb all they eat. Other mechanisms attributed to RYGB that are hypothesized to promote weight loss include²¹:

alteration of endogenous gut hormones, which promotes postprandial satiety
increased levels of bile acids, which promotes alteration of the gut microbiome
intestinal hypertrophy.

How successful is it? RYGB is associated with significant total body weight loss of approximately 35% at 2 years.⁹ The procedure has been shown to produce superior outcomes in reducing comorbid disease compared to other bariatric procedures or medical therapy alone. Of the procedures discussed in this article, RYGB is associated with the greatest reduction in triglycerides, HbA_1c, and use of diabetes medications, including insulin.²²

What are special considerations, including candidacy? For patients with mild or moderate T2D (calculated using the Individualized Metabolic Surgery Score [http://riskcalc.org/Metabolic_Surgery_Score/], which categorizes patients by number of diabetes medications, insulin use, duration of diabetes before surgery, and HbA_1c), RYGB is recommended over SG because it leads to greater long-term remission of T2D.

RYGB is associated with a lower rate of GERD than SG and can even alleviate GERD in patients who have the disease. Furthermore, for patients with limited pancreatic beta cell reserve, RYBG and SG have similarly low efficacy for T2D remission; SG is therefore recommended over RYGB in this specific circumstance, given its slightly lower risk profile.²³

What are the complications? Patients who undergo any bariatric surgical procedure require long-term follow-up and vitamin supplementation, but those who undergo RYGB require stricter dietary adherence after the procedure; lifelong vitamin (D, B₁₂, folic acid, and thiamine), iron, and calcium supplementation; and long-term follow-up to reduce the risk and severity of complications and to monitor for nutritional deficiencies.⁷ As such, patients who have shown poor adherence to medical treatment are not good candidates for the procedure.

Continue to: Early complications include...