The medical devices for treating neck-vein narrowing that Dr. Paolo Zamboni describes in a series of patent applications are raising eyebrows, with some experts suggesting they might increase the risk of internal bleeding or other complications.

Dr. Zamboni defended his inventions, however, saying the standard balloon angioplasty his centre and others used initially to treat vein stenosis is "safe and conservative" but added, "We definitely need to improve the technology of the endovascular procedure for CCSVI, developing dedicated devices."