Gastric bypass surgery is a procedure performed on the morbidly obese to help them lose weight by manipulating the size of their stomachs. After surgery, patients' stomachs can only hold small amounts of food, preventing overeating and stimulating more quickly the feeling of fullness.
While considered a safe procedure, gastric bypass does come with risks.
"Our findings show that for the low-risk group of patients, gastric bypass surgery is a very safe option. For those patients in the highest risk category, we should look at performing lower-risk or a number of smaller procedures to reduce the potential risk," study author Dr. Eric DeMaria, director of bariatric surgery at Duke University Medical Center, said in a prepared statement.
However, before this study, there was "no clinically useful system to help determine which patients would be at highest risk of dying after gastric bypass surgery," DeMaria said. "We developed a scoring system that is based on five easy-to-identify patient characteristics that can help us decide whether or not a specific patient is a good candidate for surgery and what the probable risks would be."
To devise the scoring system, a team of Duke surgeons studied data on outcomes of 2,075 bariatric surgery patients treated at Virginia Commonwealth University in Richmond between 1995 and 2004.
Thirty-one of the patients died within 90 days of their surgery. Based on these patients' histories, the researchers found that five characteristics increased the risk of death or complications from bariatric surgery:
- BMI (body mass index -- a calculation of weight versus height) of higher than 50. The normal range is between 18.5 and 25.
- Being male.
- Hypertension -- the condition is typically related to cardiovascular diseases, which can also increase risk.
- Pulmonary embolus [clot] risk -- if patients have had or are at risk for having a blood clot in the lung, their risk may be increased.
- Being over the age of 45.
"In using our system, each one of the five characteristics is worth one point. Those patients with a score of zero are at the least risk, while those with five points are at the highest risk," DeMaria said.
Only three of the 957 patients in the study who were classified as low-risk died -- a mortality rate of just 0.31 percent -- while 19 out of 999 (1.9 percent) medium-risk patients died. In contrast, nine out of the 119 high-risk patients died -- a mortality rate of 7.56 percent, the researchers noted.
The findings could have implications for treatment decision-making, DeMaria said.
"Many people see gastric bypass surgery as an option to use only when all other approaches to weight loss have failed," he explained. "However, our system shows that this strategy may need to be reconsidered. If patients put off surgery while they attempt other therapies that ultimately don't work, over time, they risk moving into a higher-risk category as they gain more weight, get older or develop hypertension. In these cases, delays can make surgery even riskier."
DeMaria presented the results of the study and the new scoring system at the annual meeting of the American Society for Bariatric Surgery, in San Francisco.
More information
Head to the Columbia University Department of Surgery to read more about gastric bypass surgery.
