Case u - Renal lacerations with active bleeding
There is a small amount of hemoperitoneum surrounding the liver and spleen. There is stranding adjacent to the head of the pancreas and tracking into the root of the mesentery. There is a large left subcapsular renal hematoma. Most importantly, there are multiple foci of active extravasation surrounding the left kidney (1, 2, 3, 4). There is also an effusion in the left lung base.
The dominant abnormality is the left renal injury. The appearance of active bleeding is typical. Extraluminal contrast collections as bright as the blood vessels are surrounded by hematoma (1, 2, 3, 4). Unfortunately, delayed images were not obtained. The patient went to angiography and active extravasation was confirmed. Gelfoam embolization was performed. Angiography should be considered in all cases of active bleeding.
This hemorrhage nicely demonstrates the anatomic regions around the kidney. At least part of the large renal hemorrhage is subcapsular. This is evident by the medial distortion of the renal contour (axial and coronal views). If the hemorrhage were extracapsular than the kidney would be displaced or rotated but not bent. Earlier you saw a subcaspular hematoma which distorted the spleen. The angiogram shows capsular arteries which extend beyond the visualized boundary of the kidney. The hematoma separates the capsule from the renal parenchyma. The angiogram confirms that the hematoma is subcapsular.
Part of the hemorrhage is present within the peri-renal space (which is the region bordered by anterior (Gerota) and posterior (Zuckerkandl) renal fascia. Notice how this area is markedly enlarged compared to the right. Increased attenuation in this area can be seen secondary to hemorrhage (trauma or bleeding tumor), renal obstruction, pyelonephritis, and lymphoma. Some hemorrhage is seen anterior to Gerota's fascia in the anterior para-renal space. The inferior portion of the posterior para-renal space communicates with the pelvic retroperitoneum and you can see some hemorrhage which has tracked into this region, and also in to the pelvis..
In a previous case we discussed that portions of the pancreas are located in the anterior pararenal space and stranding in this area is often associated with pancreatitic inflammation. However, the hemorrage in this case is physically contiguous with the renal injury. The region surrounding the pancreatic tail is normal. It does not make sense to attribute the anterior pararenal abnormalities to the pancreas.
Other foci of injury are subtle. Stranding adjacent to the pancreatic head and root of the mesentery likely represents blunt injury. There is no stranding adjacent to bowel or vessel to suggest focal mesenteric laceration or bowel injury but this is certainly not excluded. Traumatic pancreatitis (at the pancreatic head) is not excluded either.
Key points