Presentation
Abdominal pain for 12 hours, getting worse for last three hours. History of right radical nephrectomy due to renal cell carcinoma 20 years ago.
Patient Data
A few surgical clips are in the right lumbar region, which are consistent with a past history of right nephrectomy.
A large soft tissue density, obscuring the psoas muscle outlines and displacing bowel loops to the periphery, is seen in the central abdominal cavity; in view of past history of right nephrectomy, one possibility can be recurrent malignancy. Another possible differential is an aortic aneurysm.
No abnormal bowel dilatation, air-fluid levels or pneumoperitoneum is seen.
Osteopenia and degenerative changes are seen in the visualized skeleton.
Status post right nephrectomy.
Solitary left kidney with a few cortical cysts; no renal calculi or significant hydronephrosis is seen.
A well-defined hypoechoic structure measuring 80 mm in diameter having arterial flow on color Doppler ultrasound examination is seen in the central abdomen at the level of left renal hilum; it is highly suspicious for an abdominal aortic aneurysm and needs urgent CT abdomen for further evaluation.
Aneurysmal dilatation of the abdominal aorta, beginning just below the level of the left renal artery and extending inferiorly to just above the aortic bifurcation. Aneurysm measures approximately 9.3 x 7.5 x 10.8 cm (side to side x anteroposterior x craniocaudal dimensions).
A well-defined crescent shape high density (with an average density of 50 Hounsfield units), encasing 3rd part of the duodenum, is seen around the anterior and right lateral aspect of the aneurysm, which is highly suspicious for a contained rupture/hematoma. Fat stranding is noted in the surroundings of this hematoma and in right paracolic gutter.
Minimal water density fluid is seen around the liver and in the pelvis.
Status post right nephrectomy. A few cortical cysts in are seen in the left kidney. No renal calculi or significant hydronephrosis is seen. Empty urinary bladder with a Foley's catheter in situ.
Generalized decreased bone density and degenerative changes are seen in the visualized skeleton.
Abdominal radiograph 4 weeks after surgery: large soft tissue density, seen in the central abdominal cavity on initial study is no longer appreciable.
Case Discussion
The patient presented to the emergency department with central and lower abdominal pain which started 12 hours ago and was getting worse for the last three hours. The patient was found hypotensive (despite a history of hypertension) and anuric in the emergency department. Laboratory investigations showed acute renal failure.
Due to acute renal failure (with single left kidney), an urgent plain CT abdomen was performed after abdominal x-ray and renal ultrasound examination which showed ruptured abdominal aortic aneurysm, as described above. Due to hemodynamic instability, the patient was taken to the operating room immediately after the CT scan for open surgical repair. Contained ruptured infra-renal abdominal aortic aneurysm was found on surgery which was repaired. The patient recovered smoothly from surgery and was discharged in a stable condition after one week.
Interestingly, the patient had no previous history or imaging documentation of abdominal aortic aneurysm.