Teaching Case

27-year-old male patient presented to the Emergency Department with left upper quadrant abdominal pain, described as dull and increasing in severity over the previous two hours with associated left shoulder pain. The patient had been in a car accident two days before without wearing a seat belt.

The spleen is lacerated at its inferior pole, with the laceration extending to the hilum (Grade IV). There is an intraparenchymal splenic haematoma (Figures 1, 2 and 3). There is also a large subcapsular haematoma and extensive intraperitoneal haemmorhage in the left upper quadrant (Figures 4 and 5). No active extravasation of contract is present. Also, there are partially healed rib fractures of the left lower ribs posteriorly.

a) The spleen is the abdominal organ most commonly damaged in blunt trauma, despite protection from the rib cage. Although splenic rupture most commonly occurs immediately after trauma, in rare instances rupture can be delayed by days or weeks [1]. Delayed splenic rupture is defined as the late occurrence of signs and symptoms in haemodynamically stable patients, 48 hours or more after trauma [2]. The importance of delayed splenic rupture lies in its significantly higher mortatlity rate of 5-15% compared to the 1% mortality rate associated with acute splenic rupture [3].
b) Haemodynamic instability is the most common sign of patients presenting with delayed splenic rupture. However, as in the case of our patient, the haemoglobin level may be normal and acute abdominal pain associated with haemoperitineum may be the only clinical sign at presentation. CT imaging is a useful modality in the assessment of splenic injury and aids in the decision of conservative versus operative management [1, 5]. A grading scale based on CT imaging purposed by Buntain el al is used to assess the extent of the injury, but has drawbacks. In some instances, the grade may not correctly correspond to the clinical situation [6]. In the above case, the patient had a grade IV injury (hilar involvement), but was stable on presentation with a haemoglobin level of 13.5 g/dL. Due to his haemodynamic status the patient was originally treated conservatively and it was only after his Hb deteriorated to 7.5g/dL that he underwent emergency splenectomy.
c) In rare instances, an initial CT may be normal following a splenic injury and the extent of the injury is only discovered on repeat CT hours or days later. The most common theory for this phenomenon is that the original CT may have been preformed too early after the injury and not enough time was given for a subcapsular haematoma to evolve or be detected on imaging [4].
d) Similiarly, CT may under or over estimate the extent of injury and not correspond to the operative findings. In the case of this patient, his grade IV injury on CT was upgraded to V during the operation as his spleen was shattered in multiple areas. e) CT is the imaging modality of choice in delineating the presence or absence of splenic injury [6]. However, the decision for conservative versus operative treatment should be made based on multiple clinical parameters and not on CT grading scale alone.