Gastric bypass results in sustained weight loss for seriously obese patients, however perioperative complications can be formidable.
Preoperative risk assessment is important in order to establish the risk-benefit ratio for patients undergoing these operations.
In this study, published in the November issue of Annals of Surgery, researchers determined preoperative risk factors predictive of adverse outcomes after gastric bypass surgery.
The research team collected data from 1067 consecutive patients undergoing gastric bypass surgery at the UCLA Medical Center, Los Angeles, between 1993 and 2000.
They performed univariate analyses for 10 individual risk factors in order to determine their potential significance as predictors for complications.
Additionally, all 10 risk factors were entered into a logistic regression model to establish their significance as predictors.
A sensitivity analysis was also performed.
|Risk in male patients increased from 7%, for a 200-lb patient, to 13%, for a 600-lb patient.|
|Annals of Surgery|
The univariate analysis revealed that male gender and weight were predictive of severe life-threatening adverse outcomes.
However, multistep logistic regression yielded only male gender as a risk factor.
Furthermore, male patients were heavier than female patients on entry to the study, possibly accounting for weight as a potential risk factor.
The research team found that patients over 55 years had a threefold higher mortality, compared to younger patients.
The complication rate was 6% in both groups.
In addition, sensitivity analysis demonstrated that the risk for severe life-threatening adverse outcomes in women increased from 4%, for a 200-lb female patient, to 8%, for a 600-lb patient.
For male patients the risk increased from 7%, for a 200-lb patient, to 13%, for a 600-lb patient.
Dr Edward Livingston's team concluded, "Large male patients are at greater risk for severe life-threatening complications than smaller and/or female patients".
"Risk factors thought to be predictive of adverse outcomes, such as a history of smoking or diabetes, proved not to be significant in this analysis".
Furthermore, "Older patients had the same complication rate but a threefold higher mortality, suggesting that they lack the reserve to recover from complications when they occur".