ASBS: Scoring System Predicts Bariatric Bypass Surgery Mortality

SAN FRANCISCO, June 29 ? The 90-day risk of mortality from gastric bypass surgery can be calculated by a simple scoring system based on patient characteristics.

So reported Duke bariatric surgeons who found that men older than 45 with hypertension who are morbidly obese are at a significantly greater risk for dying after gastric bypass surgery than others who undergo the procedure.

A simple scoring system based on five patient characteristics - age, hypertension, body mass index, gender, and pulmonary embolus risk - can help to predict which patients are at greatest risk for death after undergoing gastric bypass, said Eric DeMaria, M.D., of Duke in Durham, N.C., and colleagues.

"When talking to patients, we can cite national averages on risks, but that is not very helpful when I have a specific patient sitting in front of me," said Dr. DeMaria, who described the scoring system at the American Society for Bariatric Surgery meeting here. "We needed a scientifically valid way for assessing individual risk."

The researchers developed the obesity surgery mortality risk score after conducting a retrospective review of 2,075 patients who had bariatric surgery from 1995 through 2004 at Virginia Commonwealth. Thirty-one of the patients died within 90 days of the procedure. In an analysis of the deaths, the investigators came up with four patient characteristics that appeared to be associated with a risk for death (a fifth criterion, age, was added later).

Under the system, patients get one point for each of the following characteristics:

• A body mass index of 50 kg/m² or greater^.
• Male gender. Men are more likely than women to have comorbidities such as hypertension, diabetes, or metabolic disorder.
• Hypertension
• Pulmonary embolus risk or history of previous embolus
• Patient age. In previous studies, patients older than 45 years of age have been shown to be at highest risk for death after gastric bypass procedures.

Among the 957 patients in the low-risk category (score of zero or one), there were three deaths (0.31%), and none of the 356 patients with zero points on the scoring system died.

Among patients with a score of two or three (medium risk), there were 19 deaths among 999 people (1.91%). Among the 119 patients in the high-risk group (score of four or five), there were nine deaths, for a 7.56% mortality rate.

No data concerning statistical significance were provided.

"Many people see gastric bypass surgery as an option to use only when all other approaches to weight loss have failed," Dr. DeMaria said. "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."

"Our findings show that for the low-risk group of patients, gastric bypass surgery is a very safe option," he added. "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."

The scoring system, if validated in prospective studies, could help surgeons with treatment planning and give patients additional information on which to base their decisions during informed consent, the investigators said.