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Renal trauma

A haemodynamically stable patient with a renal injury is managed conservatively at almost every grade; embolisation is used for active bleeding, and surgery is reserved for instability that does not respond to resuscitation, an expanding or pulsatile haematoma and avulsion of the hilar vessels.

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Why it matters in the exam

The exam shows a patient after a crash, fall or stabbing with haematuria, and asks when to perform CT, how to grade, and what the absolute indication for surgery is. Contrast CT, including a delayed phase to show urinary extravasation, is needed in a stable patient with gross haematuria, with microhaematuria and systolic blood pressure below 90 at any point, with a rapid deceleration mechanism, with significant flank trauma and with any penetrating injury where the kidney is suspected. In children — also microhaematuria above 50 red cells per field.

AAST grading, 2018 version: grade I — contusion or subcapsular haematoma without laceration; grade II — perirenal haematoma within Gerota fascia or laceration up to 1 cm without urinary extravasation; grade III — laceration over 1 cm without collecting system injury, or vascular injury or active bleeding contained within Gerota; grade IV — laceration into the collecting system with urinary extravasation, renal pelvis injury, segmental vessel injury, active bleeding beyond Gerota or segmental infarction; grade V — laceration or thrombosis of the main artery or vein, a shattered kidney or a devascularised hilum.

Most injuries, including grade IV and many grade V in a stable patient, are treated conservatively: rest, monitoring of haemoglobin and vital signs, and antibiotics when there is urinary extravasation. Selective embolisation is used for active bleeding, a pseudoaneurysm and an arteriovenous fistula, also as a late complication after partial nephrectomy. A persistent or enlarging urinoma is treated with a JJ stent or drainage. When the patient goes to laparotomy because of instability and there is no imaging, a one-shot intraoperative pyelogram (2 mL per kg) can confirm a functioning contralateral kidney. Late complications: secondary bleeding and hypertension (Page kidney).

Key points

• Conservative treatment is the default in a stable patient.
• CT with a delayed phase: gross haematuria or microhaematuria with shock.
• Grade IV = urinary extravasation or a segmental vessel.
• Embolisation for active bleeding.
• Surgery: instability, expanding haematoma, hilar avulsion.

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Sources

• EAU Guidelines on Urological Trauma, 2025 edition — Renal trauma
• AUA Guideline: Urotrauma, 2020 — Renal trauma
• AAST Organ Injury Scale: Kidney, 2018 revision — Kidney injury scale

Sources are given for further reading; the text is written afresh and not copied from them.

Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.