Press Release March 28, 2006

Aptus Endosystems Receives $19.5 Million in Series B Financing

BOSTON, March 28, 2006 — Aptus Endosystems Inc., a medical device company developing advanced technology and products for the treatment of endovascular aneurysm repair, today announced it has raised $19.5 million in Series B financing. This latest round was led by Prism Venture Partners and joined by Baird Venture Partners, both new investors. Existing investors U.S. Venture Partners and Pequot Ventures also participated in this round.

Goodwin Procter attorneys Kingsley Taft, Steven Frank and Matthew Rowe represented Prism Ventures in this transaction.