After lumbar spine surgery, my wife had such low blood pressure the doctors thought she was hemorrhaging inside. They opened her up again, but didn't find anything. Was this second operation really needed?

Most likely, yes. Surgeons have a general rule. It's better to find out there isn't internal bleeding by doing a second procedure than to wait too long and lose the patient. Damage to the blood vessels after spine surgery is rare, but it can be fatal.

In a recent study of just such cases, doctors had a zero percent (0%) mortality rate during 12 years of follow-up after spine surgery. They say this success is because they watched for low blood pressure after the operation. They also didn't hesitate to look for a damaged blood vessel causing hemorrhage.

Out of 3614 cases of lumbar spine surgery in this hospital study, only three were false negatives. In those three cases, no blood vessels were injured causing the patients symptoms. The second operation was needed to make sure of that.