This blurb from the Ben Maller.com website.
Hope all goes well for Freddie.
The surgery, to replace some lining in Hoiberg's aortic vessel, is considered serious, and it's unknown how much of next season the shooting guard will miss, or whether he'll miss the entire season. The aorta is the main vessel from the heart. The concern in Hoiberg's case is that the aortic lining is expanding and might tear if not artificially replaced. The surgery is a precautionary measure. The Timberwolves have known about Hoiberg's condition since a postseason examination and encouraged him to seek medical attention. The surgeon who will perform the surgery is considered among the elite in the country and performed heart bypass surgery on Timberwolves owner Glen Taylor six years ago. Taylor recommended the surgeon to Hoiberg.