Hospitals and ambulatory surgery centers have been at odds, vying for the same patient pool. Despite hospital and regulatory challenges to the business model, ASCs have withstood market pressures and continued to gain ground with funding from private equity firms as well as an 8.7% compounded annual growth rate between 2002 and 2008. Hospitals are now warming up to their former competitors, though, and looking at more joint venture arrangements with physicians and ASC operators.