Minimally invasive endoscopic aortic valve replacement for alkaptonuria-associated severe aortic stenosis: a case report and literature review

Alkaptonuria is an inherited metabolic disease caused by a genetic deficiency of homogentisate 1,2-dioxygenase and characterized by dark-brown connective tissue related to the deposition of oxidized homogentisic acid. Pigment deposition is also observed in the cardiovascular system, such as in the coronary arteries, cardiac valves, and aorta. Because aortic stenosis may develop secondary to pigment deposition-related calcification at the aortic valve, aortic valve replacement may be necessary for severe aortic valve disease. We report the case of a 75 year-old man with alkaptonuria-associated severe aortic stenosis who was successfully treated with minimally invasive endoscopic aortic valve replacement via right anterior minithoracotomy. The tricuspid aortic valve was severely calcified and both the valve and the aortic intima were ochronotic. No perioperative complications were observed and the postoperative course was uneventful.