Case Report Submitted by:Omar Hadidi, MSIV Faculty reviewer:Sandra Oldham M.D. Date accepted:25 August 2010 Radiological Category:Principal Modality (1): Principal Modality (2): Emergency None CT

Radiological Presentations

Splenic infarct Splenic abscess Splenic laceration Splenic cyst Lymphoma Which one of the following is your choice for the appropriate diagnosis? Test Your Diagnosis

Case History Presenting:38 yo M victim of motorcycle collision + helmet Motorcycle traveling 50 mph, patient thrown 15 ft + LOC GCS 15 Method of Arrival: Life-flight Acuity: Level 2 emergent VS: BP 131/56 HR 100 RR 22 O2 sat 92% on RA

A grade 4/5 splenic laceration is identified with active jet extravasation with pooling on delayed imaging. The liver, pancreas, kidneys and adrenals reveal no evidence of injury. No bowel abnormalities identified. No free intraperitoneal air is identified. The urinary bladder is unremarkable. Splenic infarct Splenic abscess Splenic laceration Splenic cyst Lymphoma Findings: Differentials: Findings and Differentials

Splenic Abscess Usually hematogenous spread from other foci Alcoholics, diabetics, and immunocompromised most susceptible Round, irregular lesion with decreased attenuation Gas reported in 30-50% of intraabdominal abscesses Suspect with clinical signs of infection Associated with left pleural effusion Discussion

Splenic infarct Wedge shaped, decreased attenuation, at the periphery of the spleen Causes no mass effect Most commonly associated with hematological disorders such as sickle cell anemia or thromboembolic disorders such as atrial fibrillation Discussion

Splenic Cyst Large, low attenuated mass, hypoechoic on U/S Definable cyst wall HU of mass consistent with water No internal enhancement with contrast Cystic lesions can be congenital, infectious (fungal, parasitic), or neoplastic Discussion Radiographics.rsna.org

Splenic Lymphoma Either primary or lymphomatous splenic involvement, primary very rare Non-Hodgkin lymphoma most common primary tumor of spleen Can have very similar presentation to abscess, except abscesses are not accompanied by lymphadenopathy Pathologic appearance can be: solitary mass, multifocal lesions, or homogenous enlargement without discrete mass Discussion

Splenic Laceration The spleen is the most commonly injured solid organ within the abdomen and is the most vascular organ in the body. Frequently associated with other organ injuries, 40% of patients with spleen laceration also have rib fracture, 25 % of patients with left kidney injury have splenic injury Abdominal tenderness and distension only present in 50% of patients with spleen injury, hypotension in 25-30%. After blunt abdominal trauma, prompt diagnosis is necessary before systemic compromise; unstable patients require no diagnostic imaging and are referred to surgery. Be aware of Kehr’s sign: referred pain in the tip of the shoulder due to blood in the peritoneal cavity, classic sign of a rupture spleen Discussion

Splenic trauma imaging Plain films not very reliable in diagnosis of splenic injury. The signs can be very subtle, the include: left lower rib fracture, elevation of the left hemidiaphragm, inferior displacement of splenic flexure gas pattern CT is the gold standard for imaging in blunt abdominal trauma, very high sensitivity and specificity for spleen injury (>95%) Without IV contrast a intrasplenic hematoma may appear hyperattenuated compared to the spleen. With contrast should be hypoattenuating Parenchymal injury can have variable appearances, including inhomogenous enhancement of splenic parenchyma in a linear or stellate pattern. Fractured spleen appears as complete separation of splenic fragments. Subcapsular hematoma: crescentic low attenuation area, along the edge of parenchyma, with flattening of normal convex margin Intraparenchymal hematoma should be an irregular, hypoattenuating area surrounded by normal splenic tissue. High attenuation area may represent extravasation of contrast. Findings that may lead to false positives include: normal lobulation or cleft of spleen (look for smooth margins), a previous splenic infarct can mimic laceration, perisplenic fluid from ascites may resemble perisplenic hemorrhage. Discussion

AAST Spleen Injury Grading Scale –Grade I Subcapsular hematoma of less than 10% of surface area Capsular tear of less than 1 cm in depth –Grade II Subcapsular hematoma of 10-50% of surface area Intraparenchymal hematoma of less than 5 cm in diameter Laceration of 1-3 cm in depth and not involving trabecular vessels –Grade III Subcapsular hematoma of greater than 50% of surface area or expanding and ruptured subcapsular or parenchymal hematoma Intraparenchymal hematoma of greater than 5 cm or expanding Laceration of greater than 3 cm in depth or involving trabecular vessels –Grade IV - Laceration involving segmental or hilar vessels with devascularization of more than 25% of the spleen –Grade V - Shattered spleen or hilar vascular injury Discussion

Grade I Subcapsular hematoma of less than 10% of surface area Capsular tear of less than 1 cm in depth Discussion

Grade II Subcapsular hematoma of 10-50% of surface area Intraparenchymal hematoma of less than 5 cm in diameter Laceration of 1-3 cm in depth and not involving trabecular vessels Discussion

Grade III Subcapsular hematoma of greater than 50% of surface area or expanding and ruptured subcapsular or parenchymal hematoma Intraparenchymal hematoma of greater than 5 cm or expanding Laceration of greater than 3 cm in depth or involving trabecular vessels Discussion

Grade IV - Laceration involving segmental or hilar vessels with devascularization of more than 25% of the spleen Discussion

Grade V - Shattered spleen or hilar vascular injury Discussion

Treatment With advances in imaging, nonoperative management has become the standard in patients who are hemodynamically stable; observation alone has failure rates as high as 34% With the use of SAE (Splenic Artery Embolization), success rates for high grade splenic injury of 80% have been reported. 2 main methods of SAE: proximal or selective distal embolization In proximal, embolic coils are placed to occlude the splenic artery. Hemostasis from decreased blood flow promotes clot formation. Collateral blood vessels maintain perfusion to the spleen. Distal embolization utilizes a smaller catheter and moving as close to the site of injury as possible. Higher failure rates are reported for distal embolization, most likely due to undetected bleeding from vasospasm. One study reported major complication (bleeding, infarction, abscess) rates of 27% and minor (fever, pleural effusion, coil migration) complication rates of 53% post SAE. Studies following splenic function post SAE have been promising. In one study, Howell-Jolly bodies which indicate functional asplenia, were found in 2 of 24 patients. Discussion

Proposed Algorithm for Management of Splenic Trauma

Grade 4 Splenic laceration with active extravasation and subcapsular hematoma. Diagnosis

Roberts JL, Dalen K, Bosanko CM, Jafi SZ. CT in Abdominal and Pelvic Trauma. Radiographics 1993; 13: Raikhlin A, Baerlocher MO, Asch MR, Myers A. Imaging and Transcatheter Arterial Embolization for Traumatic Splenic Injuries: Review of the Literature. Can J Surg December; 51(6): 464–472. Miller LA, Mirvis SE, Shanmuganathan IC. CT Diagnosis of Splenic Infarction in Blunt Trauma: Imaging Features, Clinical Significance and Complications. Clinical Radiology 2004; 59: emedicine.com References