Intuitive Surgical (ISRG -1.65%) recorded $1.28 billion in revenue in the fourth quarter, up 22% year over year, according to preliminary results released Thursday after the closing bell. Shares of the robotic surgery company were up 2.4% in after-hours trading on the news.

The company released the unaudited results so it could discuss them during its presentation at the 38th Annual J.P. Morgan Healthcare Conference next week. Intuitive Surgical plans to report full results, including earnings, on Jan. 23, 2020.

The overall revenue was buoyed by sales of instruments and accessories used on its da Vinci Surgical Systems, which increased 24% year over year. During the quarter, Intuitive Surgical gained Food and Drug Administration approval for the SynchroSeal instrument, which is used for grasping, dissection, sealing, and transection of tissue, and approval of the E-100 generator that powers the SynchroSeal and another instrument called the Vessel Sealer Extend.

daVinci Surgical System

daVinci Surgical System. Image Source: Intuitive Surgical.

Intuitive Surgical shipped 336 systems in the fourth quarter, a 16% increase over the fourth quarter of 2018 when it shipped 290 systems. The company has increasingly used operating leases and usage-based arrangements to get its machines into the hands of surgeons without large capital outlays by hospitals. During the quarter, 126 machines were shipped under financing agreements, compared with 84 systems in the fourth quarter of 2018.

Intuitive Surgical noted that the number of procedures performed on its machines increased 19% year over year. All told, the company estimates that over 1.2 million surgical procedures were performed on the da Vinci systems in 2019, driven by growth of general surgery procedures in the U.S. and urological procedures worldwide.

The healthcare company didn't release financial guidance for 2020 but said it expects procedures to grow by 13% to 16% in 2020, a slowdown from the 18% growth in 2019.