04/09/2013 03:34 EDT | Updated 06/09/2013 05:12 EDT

Questions & answers about increasingly popular robot surgery: Is it always the best choice?

CHICAGO - Robotic surgery is being done more and more often for a variety of operations. But experts say there's a lack of strong evidence that it's any better than standard surgery in most cases — and it's usually costlier.

Q: What exactly is robotic surgery?

A: A multi-armed robot called da Vinci is used for many operations done with small incisions and tiny instruments. Prostate removal is one of the most common. Da Vinci also is used for removing the uterus, gallbladder, certain complex cancer surgeries and weight-loss operations.

Q: How does the robot do surgery?

A: A surgeon sits at a computer console in the operating room, directing the long robot arms with hand controls. The arms are tipped with tiny surgical instruments and one has a video camera that lets the surgeon view the operation on the computer screen.

Q: What are the pros and cons of using the robot?

A: Robot hands don't shake and they can twist and rotate in more directions than human hands. However, robotic operations often cost much more than more conventional surgery. They also sometimes take longer. But patients often spend less time in the hospital.

Q: Does the robot ever break or cause problems?

A: The U.S. Food and Drug Administration is looking into a growing number of reports of malfunctions and complications, including problems that resulted in deaths and injuries. There's no proof the robot was directly involved. The robot's maker says what appears to be an increase in problems really just reflects a change in the way the company reports them.

Q: If I need an operation, should I have robotic surgery?

A: Ask your doctor about the risks and benefits of using a robot versus standard less invasive surgery. And ask how many robotic operations your surgeon has done. A 2010 New England Journal of Medicine essay by a doctor and a health policy analyst said surgeons must do at least 150 procedures to become adept. But there is no expert consensus on how much training is needed.

If you're considering a hysterectomy, your doctor was recently advised by the American College of Obstetricians and Gynecologists that robotic surgery shouldn't be the first choice because there's no good data it's as good as the cheaper alternatives.