Medtronic Inc. has been shopping this winter, announcing plans to buy three privately held heart-valve replacement technology firms. On Jan. 12, the Minneapolis device maker said it would acquire Ablation Frontiers Inc. for at least $225 million. Medtronic followed that announcement on Feb. 23 by saying it would buy CoreValve Inc., a developer of aortic-valve replacement products, for at least $700 million and transcatheter heart-valve technology company Ventor Technologies Ltd. for at least $325 million.

The buyer used John Wurm, Stephen Tight, Timothy Nelson and Rhona Shwaid of its longtime counsel, Fredrikson & Byron PA, on the CoreValve deal and Fredrikson's Brian Moore and John Remakel on the Ablation purchase. The Minneapolis law firm incorporated Medtronic in 1958 and has done much of the company's legal work since.

For antitrust advice on all three deals, Medtronic is using George Cary at Cleary Gottlieb Steen & Hamilton LLP in Washington. Cleary represented Medtronic on its 2007 acquisition of Kyphon Inc. for $3.9 billion.

For banking on the CoreValve deal, Medtronic is using Rick Gustafson, Aamer Naseer, Abhi Andley, Bill Schreiber and Mark Robinson of Piper Jaffray & Co., the Minneapolis investment bank.

CoreValve, which was founded in 2001, turned to Martin Waters, Robert Ishii and Casey McGlynn of Wilson Sonsini Goodrich & Rosati PC, which has been CoreValve's lead counsel since 2006. The Irvine, Calif., seller used Luke Sarsfield and Tosa Ogbomo at Goldman, Sachs & Co. for banking advice. David Singer, a member of CoreValve's board and a principal at Maverick Capital Ltd., was once a Goldman banker. Among his fellow board members are partners from three other venture capital firms: Apax Partners Worldwide LLP and Sofinnova Partners in Paris and HealthCap/Odlander, Fredrikson & Co, AB in Stockholm and Lausanne, Switzerland.

The same Wilson lawyers led the team that represented Carlsbard, Calif.-based Ablation on its sale to Medtronic. Ablation began in 2004. Its board includes representatives from four investors: Pequot Capital Management Inc., Versant Ventures, Aberdare Ventures LP and Novartis Bioventures Ltd.