Deutsche Bank analyst Imron Zafar said in a note to investors before the open that October/November data showed that da Vinci U.S. consumable unit sales, which have historically tracked very well directionally with reported U.S. procedure growth for Intuitive Surgical, are pointing to a "significant sequential stepdown" in Q4 utilization. He is forecasting Q4 U.S. procedure growth of 16%, which Zafar noted is in-line with consensus but represents a "modest sequential deceleration" from the 18% procedure growth reported in Q3. Zafar has a Buy rating on Intuitive. In early trading, Intuitive Surgical shares are down $17.89, or 3%, to $577.87.