Step 1: This is a two-part question. The patient is young, haemodynamically stable, and FAST positive with a grade III splenic laceration on CECT. The deciding factor is whether the CT shows a contrast blush, which signals active arterial extravasation or a pseudoaneurysm.
Step 2: Part (a): no contrast blush. A stable patient with a low-to-moderate grade injury and no blush is the ideal candidate for non-operative (conservative) management with close monitoring. So part (a) answer is D, conservative management.
Step 3: Part (b): a contrast blush is now present. A blush means ongoing bleeding even though the patient is currently stable, so pure observation is unsafe and splenic salvage is still desirable in a stable patient.
Step 4: In a stable patient with a blush, splenic artery embolization controls the bleeding while preserving the spleen, avoiding the immune cost of splenectomy. This is the answer for part (b).
Step 5: Splenectomy and splenorrhaphy are operative and are reserved for haemodynamic instability or failed non-operative management, not for a stable patient who can be managed by angioembolization.
Answer for part (b): C. Splenic artery embolization.