DENVER -- Right-hander Kip Wells had blood clots removed from his right hand during a four-hour surgical procedure performed on Tuesday by Dr. Rob Thompson at Barnes Jewish Hospital in St. Louis.

Wells' condition will be re-evaluated on Wednesday, but he did avoid further surgery on a previously repaired artery under his right collar bone. He is out indefinitely.

Wells went on the disabled list on April 30, two days after a short and ineffective outing in which he walked both hitters he faced. Subsequent tests revealed the clots.

Prior to that outing, Wells had pitched effectively out of the bullpen, going 1-1 with a 2.29 ERA in 10 games, including a start in the Rockies' first game following an Opening Day rainout. He allowed 16 hits in 19 2/3 innings, but walked 14, including two intentionally.

In March 2006, Wells underwent surgery to repair a complete blockage of the axillary artery, which was replaced by a vein in his leg. That procedure also was performed by Dr. Thompson. Wells returned to pitch in nine Major League games that season, going 2-5 with a 6.50 ERA.