Steven Cherny of Kirkland & Ellis

Millions of surgical patients have benefited from artificial blood vessel grafting technology first developed back in the 1970s. If only they knew that the breakthrough that made their procedures possible unleashed four decades of patent litigation, enriched platoons of lawyers, and came awfully close to stumping the U.S. Patent and Trademark Office and a bevy of federal judges.

Maybe the patients wouldn’t care. But for us, there have been few intellectual property disputes as riveting as the battle between C.R. Bard and W.L. Gore & Associates over the vascular grafts. And now it may finally be over. On Friday the U.S. Court of Appeals for the Federal Circuit agreed with Bard’s lead counsel, Steven Cherny of Kirkland & Ellis, that Gore was infringing a Bard patent first filed 38 years ago. As we reported, the ruling affirms a 2007 jury verdict and a $660 million judgment that Cherny and his co-counsel at K&E and Latham & Watkins won for Bard in 2010. Factoring in ongoing and future royalties that Gore must now pay, Friday’s ruling is likely worth at least $800 million for Bard–and counting–potentially making it the most valuable patent award that’s ever been upheld.

The stage was first set for the litigation in 1973, when W.L. Gore approached a cardiologist named David Goldfarb about testing versions of a material now known as Gore-Tex for grafting onto blood vessels. According to the version of the story upheld by the Federal Circuit, Goldfarb fairly quickly determined exactly how to make such a graft viable by manipulating the materials Gore supplied. But Gore filed a patent application using the same specifications in 1974, claiming it was invented by the employee of the company who had furnished Goldfarb with Gore-Tex samples.

Goldfarb filed his own competing application with the patent office later the same year, sparking 28 years of litigation at the PTO and the Federal Circuit to determine who should be awarded the patent. Finally, in 2002, the Federal Circuit refused to overturn a PTO decision to award the patent to Goldfarb, who had already licensed it to C.R. Bard, and the patent was formally issued.