A 32-year-old man is brought to the emergency department following a high-speed motor vehicle collision. On primary survey, he is haemodynamically stable with a BP of 110/70 mmHg and HR 88/min. Abdominal examination reveals tenderness in the left upper quadrant with mild distension. FAST examination shows free fluid in the splenic fossa. CT abdomen with IV contrast demonstrates a Grade III splenic laceration with active extravasation and a small amount of free fluid. What is the most appropriate next step in management?