CT Case 064
A 70-year-old presents with flank pain 4 days after a renal biopsy for investigation of a renal mass. He has a previous history of bioprosthetic aortic valve and is on warfarin and aspirin.
On examination he is haemodynamically stable with a tense abdomen and right flank pain.
His haemoglobin on arrival is 120g/l (from a baseline of 150).
A CT scan of the abdomen is performed
Describe and interpret the CT images
This case demonstrates a large subcapsular haematoma and perinephric haematoma in the right peri-renal space. The angiogram demonstrates two small foci of arterial blush which show pooling on the venous phase suggesting active bleed.
The appearance of perinephric haematoma is determined by the time of bleed. In the hyperacute phase, they can appear isodense. In the acute phase, it appears hyperdense and as the blood ages, the density decreases.
Subcapsular haematoma conforms to the reniform shape of the kidney whereas a perinephric haematoma can be more irregular and dependent. A large subcapsular haematoma can compress the kidney compromising its vascular supply.
Traumatic and post biopsy haematomas can also demonstrate pseudoaneuryms which may be treated by embolization.
Compare this to CT case 30, this patient also has bleeding as a complication following renal biopsy, in case 30 there is haematoma in the perirenal and pararenal spaces.
Clinical Pearls
Given the blush on CT, he was taken to interventional radiology with plan for embolisation, however at this time there was no active bleeding therefore no vessel embolised.
He ultimately had a haemoglobin drop down to 78, this was investigated with a repeat CT which did not show any active bleeding.
Management for this patient consistent of PRBC transfusion, Vit K and factor replacement with Prothrombinex.
Despite the large haematoma and Hb drop, this patient remained haemodynamically stable throughout.
Bleeding complications are common following renal biopsy. Most (91%) present within the first 24 hours. These can range from microscopic or macroscopic haematuria, perinephric haematoma, or large retroperitoneal haematomas. Haematomas requiring angiographic intervention are very rare (0.6%).
Pre-procedure management of hypertension and coagulation can help reduce the risk of haematoma.
References
- Hartung M. Abdominal CT: genitourinary system. LITFL
- Bakdash K, Schramm KM, Annam A, Brown M, Kondo K, Lindquist JD. Complications of Percutaneous Renal Biopsy. Semin Intervent Radiol. 2019 Jun;36(2):97-103.
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Dr Leon Lam FRANZCR MBBS BSci(Med). Clinical Radiologist and Senior Staff Specialist at Liverpool Hospital, Sydney
Sydney-based Emergency Physician (MBBS, FACEM) working at Liverpool Hospital. Passionate about education, trainees and travel. Special interests include radiology, orthopaedics and trauma. Creator of the Sydney Emergency XRay interpretation day (SEXI).
Provisional fellow in emergency radiology, Liverpool hospital, Sydney. Other areas of interest include paediatric and cardiac imaging.
Emergency Medicine Education Fellow at Liverpool Hospital NSW. MBBS (Hons) Monash University. Interests in indigenous health and medical education. When not in the emergency department, can most likely be found running up some mountain training for the next ultramarathon.