Injuries to blood vessels, especially at the incision site, are among the most common problems of this procedure. These can include: blood clots, damage to the blood vessel, ongoing bleeding, a collection of blood under the skin or in the artery itself and abnormal tissue connections that form between the artery and a vein. Most of the time these are temporary problems.
For example, a collection of blood below the skin can develop into a tender mass the size of a baseball. The mass will usually disappear in 1 to 2 weeks as the blood gradually spreads out and is reabsorbed by the body. In rare cases, the injuries can require surgery to fix the problem.