** Shares of medical device maker Intuitive Surgical ISRG.O down 1.1% at $477.5

** US FDA says it is aware that Intuitive Surgical has alerted customers about a problem involving certain curved‑tip staplers used with its da Vinci robotic surgery system, after reports of incomplete staple lines during procedures on blood vessels

** As of February 23, Intuitive Surgical reported four serious injuries and one death linked to the issue, according to the FDA

** An incomplete staple line on a vessel can leave the tissue fully cut and exposed, causing bleeding that may require surgeons to convert from a minimally invasive procedure to an open surgery technique, the agency says

** Stock has been down 15.7% YTD