Washington (CNN) -- Millions of needles used in ports implanted under the skin of chronically ill patients are being voluntarily recalled, the U.S. Food and Drug Administration announced Tuesday.
More than 2 million Huber needles, manufactured by Nipro Medical Corp. in Japan and distributed by Exelint International Corp., headquartered in Los Angeles, California, are affected.
Huber needles are used primarily in hospitals and clinics -- and in some instances by patients receiving long-term treatment at home -- to draw blood or to inject medicine, other nutritional solutions or blood products. They are used with ports, which are small medical appliances placed under the skin.
The Class 1 recall -- denoting that the FDA considers the product to be of the highest risk -- involves Exel/Exelint Huber needles, Exel/Exelint Huber Infusion Sets and Exel/Exelint "Securetouch+" Safety Huber Infusion Sets.
Approximately 6 million Huber needles are used each year in the United States. The agency determined that 60 to 70 percent of Exelint's needles "cored," or cut slivers of silicone, when inserted into ports, raising the possibility of the silicone slivers entering the veins, damaging the port itself or harming the surrounding tissue.
There have been reports of leakage, the FDA said, but none of silicone entering the vascular system as a result of the needles. It said anyone using the products should stop immediately and return any unused needles to Exelint.
Investigations are being done of needles from 20 companies, and 10 of those investigations have been completed, the agency said. So far, no other products have been recalled.
The FDA said it has sent letters to all Huber manufacturers asking them to address any design or manufacturing problems.
There was no immediate public comment from Exelint.
The Japanese company Nipro has voluntarily recalled two million needles in the US used for withdrawing blood and medicine injections, health officials said today.

The affected items are Huber needles, manufactured in Japan and distributed by Exelint International Corporation. The needles are intended to access ports placed under chronically ill patients' skin, for frequent access to veins.

According to the Food and Drug Administration (FDA), inspections of Nipro facilities last October revealed problems with the needles, which could allow parts of silicone in the port to be dislodged. 60%–72% of tested needles had that problem.  In a conference call with reporters, FDA officials remarked that they were concerned the silicone could enter the bloodstream of a patient, although, to date, no harm from this has been reported.

"There are more than 2 million units impacted by this recall in distribution nationwide. Recalled needles were manufactured from January 2007 to August 2009," read a statement on the FDA's website. "... Hospitals, clinics and patients who have needles from these lists should immediately stop using these affected products and return any unused products to Exelint International Corporation."

"At this time, the FDA has not received any adverse event reports related to silicone foreign bodies released in patients from Huber needle coring ... However, because it may be very difficult for clinicians to associate adverse patient outcomes with the use of defective Huber needles, there may be under-reporting of events," the statement continued.

Exelint has not yet issued a public statement about the report from the FDA.