Medtronic Inc, which designed the world's first heart pacemaker, said a U.S. court had ordered the lifting of an injunction that had kept it from using a key stent delivery system called Rapid Exchange due to an Abbott Laboratories patent.

The vast majority of doctors use Rapid Exchange to implant stents – tiny wire mesh tubular devices that prop open diseased arteries. Medtronic, which makes insulin pumps, artificial spinal discs and heart devices, has said having access to the technology would increase its ability to gain market share.

The U.S. District Court for the Northern District of California noted in its order that Abbott would not suffer any irreparable injury due to its decision to end the injunction, Medtronic said. It ordered that the injunction be lifted on Oct. 29. Abbott is studying its options, "including a potential appeal and seeking significant damages," Abbott spokesman Scott Stoffel said.

Abbott said last week the U.S. Patent and Trademark Office had temporarily extended its Yock patent for the delivery of stents. Rapid Exchange system is covered under the Yock patent. Stoffel said the company was confident the patent office will grant it a permanent extension. It is seeking an extension till May 2011.

From a financial modeling standpoint, Abbott had planned for Medtronic to enter the market from Oct. 29, when the patent was initially set to expire, he added.The injunction was originally issued in 2000, Medtronic said, and added that it plans to announce its commercial intent related to the use of Rapid Exchange technology after the injunction ends.