Bariatric Surgery
December  2014

​​​A 57 year-old male is applying for $1 million of life insurance. He has a history of morbid obesity (Pre-op BMI of 51) and Type II diabetes. Eight months prior to application he underwent a weight reduction surgery, specifically a laparoscopic Roux-en-Y gastric bypass (LRYGB, Figure 1). He had a complication, a pulmonary embolism, during the immediate postoperative period, from which he recovered. He has lost 20% of his excess weight since the surgery. His HgbA1c level has improved from a pre-operative value of 8.1% to a current value of 6.9%. He has missed several follow-up visits with the management team, including a visit to the dietician and the psychologist. However, office visit notes do mention adherence to his postoperative medications. He otherwise has had no complications or concerns.

Two major questions arise when evaluating a case like this for mortality risk. 

  1. What are the short-term and long-term mortality implications of Roux-en-Y weight loss surgery?
  2. What is the likelihood of morbidly obese Type II diabetics undergoing Roux-en-Y weight loss surgery obtaining diabetic remission?


Let's Review a Few Facts
The World Health Organization defines a body mass index (BMI) of ≥ 40 kg/m2 as morbidly obese. Obesity incidence is increasing in the US and worldwide. In 2010 about 33.8% of the US population were clinically obese. Obesity has major mortality and morbidity concerns for an individual. Figure 2 lists major medical conditions associated with obesity that can adversely impact mortality.

Figure 2 - Conditions Associated with Morbid Obesity which can Impact Mortality
Ischemic heart diseaseDiabetes - Type II
Non-neoplastic chronic kidney diseaseCancer (e.g., breast, prostate, liver, kidney, endometrial, colon, cervical, thyroid, overlan, leukemia) 
sleep apneaHypertension
DyslipidemiaCongestive heart failure
Atrial fibrillationCVA 
DVT and PEInfection 
Depression 

Morbid obesity increases the likelihood of many impairments that adversely affect mortality, as noted in the table above.

Over the last several decades an increasing number of obese individuals have undergone weight reduction surgery (when more conventional weight loss programs have failed). In 2011 approximately 340,000 weight reduction surgeries were performed worldwide, with about 220,000 of those being done in the US. Many studies show short-term weight loss effects, including the impact weight loss has on some weight-related comorbid conditions. Unfortunately, few studies document long-term results. Does the length of time an individual carried excessive weight influence outcomes? Does the age that excessive weight was first added matter? These and other questions have not yet been answered. 

Figure 3 outlines the combination of BMI and comorbid conditions where bariatric surgery may be advisable in adults. 

Figure 3 - Indications for Bariatric Surgery in Adults
BMIComorbid Condition
≥ 40kg/m^2No comorbid condition needed
35/39.9kg/m^2, with at least one of the following comorbid conditionsDiabetes, Type IIObstuctive sleep apnea
Obesity-hypoventilation syndromeAsthma
HyperlipidemiaHypertension
Gastroesophogel reflux diseaseNonalcoholic steatohepatitis
Severe arthritis Pseudotumor cerebri
30-34.9kg/m^2 with comorbidityUncontrollable Type II diabetesMetabolic syndrome

As outlined by the National Institute of Health Consensus Development Panel in 1991 and endorsed by the American Bariatric Society in 2004, recommendation for surgery depends on both BMI and comorbid factors.

Several surgical procedures (e.g., jejuno-ileal bypass, gastroplasties) have been largely abandoned due to either excess morbidity or mortality and/or ineffective results. Other surgical procedures are currently being performed (Figure 4). Bariatric surgeries can be categorized into either restrictive or malabsorptive procedures, with some surgeries combining elements of both. Restrictive procedures restrict the volume of the stomach in some way. The restriction significantly limits the amount of solid foods that an individual can ingest at a sitting. Such procedures are generally associated with more gradual weight loss. 

Figure 4 - Commonly Performed Bariatric Surgery Producers
ProcedureMechanism of Weight LossFrequencyTypical % of Excess Weight Loss
Roux-en-Y gastric bypassRestrictive and malabsorptive47%70% (2yr.)
Sleeve gastrectomyRestrictive28%60% (2yr.)
Laparoscopic adjustable gastric bandRestrictive 18%50%-60% (2yr.)
Bilio-pancreatic diversion with duodenal switchRestrictive and malabsorptive<5%70%-80% (2yr.)
Mini-gastric bypassRestrictive and malabsorptive<5%50% (18 mo.)

The Roux-en-Y procedure is one of the most common and effective (short-term) bariatric surgeries performed today.

Malabsorptive procedures diminish the absorption of consumed nutrients by making food bypass part of the intestine where absorption occurs. These procedures are more difficult technically than restrictive-type procedures.

Bariatric Surgery Benefits
Bariatric surgery has demonstrated a number of benefits. Short-term medical outcomes for morbidly obese Type II diabetics undergoing weight reduction surgery include:

Weight loss. Typical weight loss depends on several factors including the type of procedure performed (Figure 4, next page). Before surgery practitioners calculate excess weight by determining the weight that exceeds a BMI value of 25 kg/m2. After surgery weight loss in most studies ranges from 50%-80% of excess body weight. 

Diabetes. In 2011 the American College of Surgeons Bariatric Surgery Center Network reported the results of 28,616 patients. One year after surgery, 83% of patients undergoing a Roux-en-Y gastric bypass, 55% receiving a sleeve gastrectomy procedure and 44% undergoing an adjustable gastric band procedure had remission or improvement in their diabetes.

Other comorbid conditions. The same American College of Surgeons’ report indicated improvement in other comorbid conditions, including improvement in hypertension, sleep apnea and hyperlipidemia. Multiple studies have documented similar improvements.


Complications of Bariatric Surgery 
Serious short-term complications of bariatric surgery include pulmonary embolism, myocardial infarction and/or return to the operating room for revisions or repair of stenosis, obstruction or anastomotic leaks. Some bariatric surgery centers quote a 10%-20% follow-up operation rate after bariatric surgery. The type of procedure affects short-term complication rates.

Generally speaking, laparoscopic-type procedures have less morbidity and mortality than open procedures, and laparoscopic adjustable gastric band (LAGB) procedures have less morbidity than laparoscopic Roux-en-Y gastric bypass (LRYGB) procedures. Morbidity outcomes associated with laparoscopic sleeve gastrectomy procedures fall somewhere between the LAGB and LRYGB procedures. Perioperative mortality rates are similar among these three procedures. The overall 30-day postoperative mortality rate is typically less than 1% according to the most recently published series.

Bariatric surgery mortality rates are higher for individuals who exhibit:

  • More complex operations
  • Development of any adverse intraoperative or in-hospital event (e.g., PE, acute respiratory failure)
  • BMI ≥ 50 kg/m2
  • Older age (>65 years of age)
  • Medical comorbid conditions
  • Male gender
  • Low-volume of bariatric procedures by surgeons and in hospitals

Serious long-term complications of bariatric surgery include short bowel syndrome, dumping syndrome, metabolic and nutritional derangements, renal failure and postoperative hypoglycemia. Complications may be short-term or long-term, such as stenosis, obstruction and leaks. In addition, many of those undergoing surgery regain excess weight. 

Physicians have not studied the long-term remission of Type II diabetes enough to fully understand the expected benefits. However, a recent article published in JAMA analyzed the findings of 343 diabetic bariatric surgery patients in Sweden. Two-year diabetes remission rates were 16.4% in the control group and 72.3% in the bariatric surgery group. At 15 years, the remission rate was 6.5% in the control group and 30.4% in the bariatric surgery group. They also found that longer-duration diabetes (≥4 years at time of surgery) was less likely to remit than shorter-duration (<1 year) disease.

This same study evaluated microvascular and macrovascular complications, finding a decrease in both in the surgical groups. In fact there was a 43% reduction in myocardial infarction and 31% reduction in overall mortality. Larger long-term studies may confirm benefit likelihood. 

In summary, obese individuals frequently choose bariatric surgery to control excess weight. Short-term complications from the surgery are possible, and the rates and types of complication can vary based upon type of surgery. We’re still studying the long-term benefits and complications, and we lack conclusive findings for now. However, short- and long-term findings in several studies are quite encouraging.

Returning to the Case
The applicant has lost a considerable amount of weight already, which is not unusual for this type of procedure. It is not uncommon to experience rapid weight loss over the first six months (10-15 pounds/month), continuing through the following 12-18 months (5-7 pounds/month) until eventually plateauing.

The improvement in his hemoglobin A1c is also fairly typical. Improvement in diabetics’ metabolic control is noticeable within days or weeks after a LRYGB procedure. He also has had no known surgical complications following hospital discharge from the LRYGB procedure.

The failure to adhere to medical follow-up, however, might be a red flag. Adherence to appropriate medical follow-up is helpful to ensure long-term success with weight loss and to monitor the need for medications to avoid hypoglycemic reactions, to evaluate for surgical complications and to monitor for any longer-term nutritional deficiencies.

Finally, he does have several of the factors involved in potentially increased mortality (i.e., perioperative complication, BMI >50). All of these factors will have an impact on the individual consideration of this case. Given the procedure performed, he may still lose another 50% of his excess body weight, although one might expect this to have occurred in the eight months since surgery. At a minimum he should be evaluated at the current control of the Type II diabetes.


References

Shields, M. Carroll, et al. “Adult obesity prevalence in Canada and the United States.” NCHS data brief no. 56. National Center for Health Statistics, 2011.

Buchwald, H. “Metabolic/bariatric surgery worldwide 2011.” Obesity Surgery. 2013 Apr;23(4): 427-36.

Lim, Robert B. et al. “Bariatric surgical operations for the management of severe obesity: descriptions.” UpToDate. Accessed 10/17/2014.
 
Hutter, MM, Schirmer BD, et al. “First report from the American College of Surgeons Bariatric Surgery Network: laparoscopic sleeve gastrectomy has morbidity and effectiveness positioned between the band and the bypass.” Ann Surg. 2011;254(3):410.

Cleveland Clinic Bariatric and Metabolic Institute Risk and Complications patient information. https://weightloss.clevelandclinic.org/images/file/Risks%20and%20complications%20of%20bariatric%20surgery.pdf. Accessed 11/6/14. 

Lim, Robert B et al. “Bariatric operative procedures: Thirty-day morbidity and mortality.” UpToDate. Accessed 11/6/14.
 
Schernthaner, Guntram, et al. “Bariatric surgery in patients with morbid obesity and type 2 diabetes.” Diabetes Care, volume 31, supplement 2, 2008 Feb. 5207-5302.

Sjostrom, Lars, et al. “Association of Bariatric Surgery With Long-term Remission of Type 2 Diabetes and With Microvascular Complications.” JAMA. 2014;311(22):2297-2304. ∞