Clinical Review

Weight Loss Promotes Nonbariatric Surgery Medical Clearance

A liquid-based weight-loss program had a high success rate among obese veterans, was cost-effective, and reduced the need for surgery.

Fed Pract. 2015 April;32(4):20-25

Author(s):

Julie L. Kurtz, MS, RD, CDE

Ashley M. Bremer, CDE

Diane J. Parrington, PhD, RD

Dawn C. Schwenke

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References

1. Flegal KM, Carroll MD, Ogden CL, Johnson CL. Prevalence and trends in obesity among US adults, 1999-2000. JAMA. 2002;288(14):1723-1727.

2. Ogden CL, Flegal KM, Carroll MD, Johnson CL. Prevalence and trends in overweight among US children and adolescents, 1999-2000. JAMA. 2002;288(14):1728-1732.

3. Flegal KM, Carroll MD, Ogden CL, Curtin LR. Prevalence and trends in obesity among US adults, 1999-2008. JAMA. 2010;303(3):235-241.

4. Ogden CL, Carroll MD, Curtin LR, Lamb MM, Flegal KM. Prevalence of high body mass index in US children and adolescents, 2007-2008. JAMA. 2010;303(3):242-249.

5. Flegal KM, Carroll MD, Kit BK, Ogden CL. Prevalence of obesity and trends in the distribution of body mass index among US adults, 1999-2010. JAMA. 2012;307(5):491-497.

6. Das SR, Kinsinger LS, Yancy WS Jr, et al. Obesity prevalence among veterans at Veterans Affairs medical facilities. Am J Prev Med. 2005;28(3):291-294.

7. Drawert S, Bedford K, Largent D. Change in glucose, blood pressure, and cholesterol with weight loss in medically obese patients. Obes Res. 1996;4(suppl 1):67S.

8. Kirschner MA, Schneider G, Ertel NH, Gorman J. An eight-year experience with very-low-calorie formula diet for control of major obesity. Int J Obes. 1988;12(1):69-80.

9. Wadden TA, Foster GD, Letizia KA, Stunkard AJ. A multicenter evaluation of a proprietary weight reduction program for the treatment of marked obesity. Arch Intern Med. 1992;152(5):961-966.

10. Anderson JW, Brinkman-Kaplan VL, Lee H, Wood CL. Relationship of weight loss to cardiovascular risk factors in morbidly obese individuals. J Am Coll Nutr. 1994;13(3):256-261.

11. Huerta S, Dredar S, Hayden E, et al. Preoperative weight loss decreases the operative time of gastric bypass at a Veterans Administration hospital. Obes Surg. 2008;18(5):508-512.

12. Still CD, Benotti P, Wood GC, et al. Outcomes of preoperative weight loss in high-risk patients undergoing gastric bypass surgery. Arch Surg. 2007;142(10):994-998; discussion 999.

13. Pekkarinen, T, Mustajoki P. Use of a very low- calorie diet in preoperative weight loss: Efficacy and safety. Obes Res. 1997;5(6):595-602.

14. Van Nieuwenhove Y, Dambrauskas Z, Campillo-Soto A, et al. Preoperative very low-calorie diet and operative outcome after laparoscopic gastric bypass: A randomized multicenter study. Arch Surg. 2011;146(11):1300-1305.

15. Hauser DL, Titchner RL, Wilson MA, Eid GM. Long-term outcomes of laparoscopic Roux-en-Y gastric bypass in US veterans. Obes Surg. 2010;20(3):283-289.

16. Livingston EH, Arterburn D, Schifftner TL, Henderson WG, DePalma RG. National Surgical Quality Improvement Program analysis of bariatric operations: Modifiable risk factors contribute to bariatric surgical adverse outcomes. J Am Coll Surg. 2006;203(5):625-633.

17. National Joint Registry. 11th Annual Report 2014: National Joint Registry for England and Wales and Northern Ireland. Hemel Hempsted, England: National Joint Registry; 2014.

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20. Krushell RJ, Fingeroth RJ. Primary total knee arthroplasty in morbidly obese patients: A 5- to 14-year follow-up study. J Arthroplasty. 2007;22 (6 suppl 2):77-80.

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The prevalence of overweight and obesity has continued to increase over the past several decades.^1,2 Data specific to the veteran population indicates prevalence rates are considerably higher than that of the general population, with overweight or obese veteran women and men at 68.4% and 73%, respectively.^3-6

Traditional weight-loss programs (> 1,200 calories per day) fail to produce the degree of weight loss required to reduce surgical risk to a safe level for individuals with a body mass index (BMI) > 35. In contrast, intensive weight-loss programs using very low calorie diets (< 800 calories per day) combined with lifestyle modifications have been effective in generating considerable weight loss. These intensive weight-loss programs have also improved comorbid conditions such as insulin resistance, diabetes, hypertension, hyperlipidemia, and hypertriglyceridemia.^7-10 Additionally, these programs have reduced surgical risks by decreasing operative time and reducing hospital length of stay.^11,12 Weight loss not only improves surgical risk, but also impacts health care resource allocation.

Very low calorie diets have proven to be safe for preoperative weight loss. One prospective study evaluated the safety of a weight-reduction program with 30 patients with morbid obesity and whose elective surgery had been postponed due to patient’s weight status.¹³ Study participants lost ≥ 15% of their body weight. Subsequently, only 15 patients underwent surgery. Surgery was no longer indicated for 4 participants, 9 did not have surgery for reasons that were unreported, and 2 discontinued the diet. The authors suggested a very low calorie diet program is suitable for preoperative weight reduction in morbid obesity without significant complications.

Most investigations of preoperative very low calorie diets included only those patients awaiting bariatric surgery. These studies confirmed bariatric preoperative weight loss correlates with reduced postoperative complications.^11,14,15 Additionally, the National Surgery Quality Improvement Program analysis of bariatric outcomes identified superobesity (defined as > 350 pounds) as a preoperative risk factor associated with postoperative complications.¹⁶

Obesity-related intra- and postoperative complications during elective surgeries are concerning because of the increasing number of obese surgical patients. With a growing aging population and rising rates of obesity, the number of total knee arthroplasties (TKAs) are increasing and now surpass total hip arthoplasties.¹⁷The risk of intra-operative surgical complications is higher in patients with an elevated BMI than in those without, including higher blood transfusion requirements as a result of operative blood loss, difficulty in identifying anatomy leading to iatrogenic damage, or malalignment of the prosthesis.^18-20

The risk of postoperative complications in obese patients is reported with rates as high as 32% and is primarily caused by superficial and deep surgical site infections and postoperative venous thromboembolic complications.^18,19,21,22 One retrospective study evaluated prevalence, pattern, and severity of 7,721 postoperative complications in obese and nonobese surgical patients occurring within 30 days of surgery.²³ Obese patients had significantly higher rates of postoperative myocardial infarction, wound infection, nerve injury, and urinary tract infections. The evidence suggests a higher risk of intra- and postoperative complications of TKA in obese patients, but there remains continued controversy in this area. Furthermore, there is a paucity of data regarding actual postponement or cancellation rate in elective procedures related to obesity. There is a lack of literature evaluating the impact of significant preoperative weight loss by nonsurgical interventions on outcomes of subsequent elective surgery.

The primary aim of this study was to determine whether a medically supervised, very low calorie weight loss program (Optifast, Nestlé Health Science) could safely and effectively produce the weight loss necessary to achieve surgical clearance at the Phoenix VA Health Care System (PVAHCS). The secondary aim was to determine whether a decrease in medication utilization during the diet intervention would offset the cost of the nutrition intervention.

Methods

This was a prospective, theory-based pilot study exploring weight status in response to a very low calorie diet, utilizing a quasi-experimental design. The PVAHCS Institutional Review Board approved the study.

Subjects participated in a medically supervised weight-loss program, including a liquid-meal replacement and weekly education administered by a registered dietitian. Twenty male and female veterans with obesity who had been denied medically indicated nonbariatric elective surgery due to obesity/morbid obesity and who met the study’s inclusion criteria were recruited.

Inclusion criteria included veterans aged 18 to 70 years, BMI > 30, and a nutritional consult for weight loss prior to elective (nonbariatric) surgery. The exclusion criteria included active medical conditions for which weight loss would be contraindicated, active alcohol or substance abuse, and psychological issues that could prevent compliance.