Renal Trauma Repair

Operative repair of renal trauma has become uncommon: accurate CT staging and the success of non-operative management mean most renal injuries — even deep lacerations and many penetrating injuries — are managed without surgery. The kidney is the most commonly injured genitourinary organ, and the main indication for exploration is hemodynamic instability. When operative repair is undertaken, the goals are to control bleeding, salvage renal parenchyma, and avoid the delayed complications of non-operative failure. Renal trauma grading, imaging, and the non-operative pathway are covered in the Trauma topic; this page is the operative reference.

Indications for Operative Repair

• Stable patients are managed non-operatively (grade I–III with excellent preservation; many grade IV–V stable injuries too) — close monitoring, bed rest, and transfusion/imaging as needed.
• The main indication for exploration is hemodynamic instability: a critically unstable patient undergoes immediate exploration to control intra-abdominal bleeding and may need a damage-control nephrectomy to avoid mortality.
• CT findings that most often require intervention — a medial hematoma or laceration, or a rapidly expanding perirenal hematoma (> 3.5–4 cm) with vascular contrast extravasation.
• A segmental vascular injury causing continued hemorrhage can be controlled with angiographic embolization, avoiding open exploration — but a patient unstable despite resuscitation goes to the operating room, not to angiography.

AAST Grading

Grade	CT criteria
I	Subcapsular hematoma and/or contusion, no laceration
II	Perirenal hematoma confined to Gerota's; laceration ≤ 1 cm without urinary extravasation
III	Laceration > 1 cm without collecting-system rupture; or a vascular injury/active bleeding contained within Gerota's
IV	Laceration into the collecting system with extravasation; renal-pelvis laceration/complete UPJ disruption; segmental vessel injury; or segmental/complete infarction without active bleeding
V	Main renal artery/vein laceration or hilar avulsion; a devascularised kidney with active bleeding; or a shattered kidney

Advance one grade for bilateral injury, up to grade III.

Exposure and Vascular Control

A midline transabdominal incision from the xiphoid to the pubic symphysis gives optimal exposure for full abdominal exploration and access to the great vessels; control immediate bleeding with laparotomy packs.

1. Expose the retroperitoneum — place the transverse colon onto the chest over a moist pack and retract the small bowel to the patient's right and superiorly to reach the retroperitoneum, IVC, and aorta. Identify the inferior mesenteric artery (IMA) and make an incision superior to it down to the aorta, carried cephalad to the left renal vein (which crosses anterior to the aorta in ~95%). With a large obscuring hematoma, use the inferior mesenteric vein (IMV) as a landmark — incise medial to it up to the ligament of Treitz.
2. Isolate the hilar vessels — the left renal vein is always identified first (even for a right-sided injury); both renal arteries lie posterior and slightly superior to it. Find the right renal artery in the inter-aortocaval space by elevating the left renal vein and dissecting the medial aorta, and the right renal vein on the lateral IVC at about the level of the left renal vein (mobilise the second part of the duodenum for a right hilar injury). Place vessel loops around the artery and vein of the injured kidney before opening the hematoma.
3. Expose the kidney — after vascular control, mobilise the kidney via the Mattox maneuver (left) or the Cattell maneuver (right).

Entering the Hematoma and Renal Exposure

Mobilise the colon medially by incising the white line of Toldt, open Gerota's fascia sharply, and evacuate the perirenal hematoma. Do not clamp the hilar vessels unless bleeding cannot be controlled by manual compression — leaving them looped but un-clamped avoids warm ischemia. Fully mobilise and inspect the kidney to define the injury and identify the entrance and exit wounds of a penetrating injury (to avoid a missed injury). To repair a pole in a bloodless field, an atraumatic bowel clamp (e.g. a Doyen) can be placed across the kidney above or below the hilum to exclude that pole without occluding the renal artery.

Reconstructive Principles

Five principles apply to every renal repair:

1. Complete renal exposure.
2. Sharp debridement back to viable tissue.
3. Hemostasis by oversewing end-on (cut) vessels.
4. Watertight collecting-system closure.
5. Defect coverage.

Repair Techniques

• Renorrhaphy (deep laceration) — remove the overlying clot to expose the full injury, sharply debride nonviable edges, suture-ligate bleeding parenchymal vessels, and close the collecting system watertight with continuous absorbable suture. Apply hemostatic/tissue sealant to the defect, then place interrupted 3-0 capsular sutures loosely over Gelfoam bolsters, and cover the repair with omentum when available.
• Partial polar nephrectomy (large pole injury) — sharply remove the devitalised pole in guillotine fashion, oversew end-on vessels, and close the collecting system watertight. Where the capsule is inadequate, cover with omentum (rich blood supply, absorbent, aids healing) or tailored polyglactin (Vicryl) mesh secured with interrupted sutures (the mesh resorbs by hydrolysis over 55–70 days with minimal reaction).
• Penetrating (stab) injury — entrance and exit wounds can be oversewn and combined with viscous thrombogenic agents; an associated collecting-system injury usually resolves with closure of the overlying parenchyma and should not be aggressively pursued.

Vascular Injuries

Complex acute vascular reconstruction is reserved for a solitary kidney or bilateral severe injuries — confirm a functioning contralateral kidney first (intraoperative one-shot IVP, ultrasound, CT, or exploration) before any nephrectomy. A partial main renal vein or artery injury is primarily repaired after proximal and distal control with a continuous 4-0 Prolene suture; segmental arteries and veins are individually suture-ligated. Renal-artery thrombosis or complete division is rarely salvaged acutely (direct repair or vein-graft bypass, with vascular-surgery support, only for a solitary kidney or bilateral injury).

Drains and Stents

If a collecting-system injury is suspected, place a Penrose or passive (non-suction) flank drain through a separate incision — avoid suction drains, which may potentiate a urinary fistula. A ureteral stent is not placed at the initial exploration in the absence of a ureteral injury.

Postoperative Care

• Check a postoperative hematocrit and limit activity until the hematuria clears (often within ~24 hours).
• Check the perirenal drain for creatinine and remove it within ~48 hours to avoid infecting the retroperitoneum; a detected urinary leak is treated by placing a ureteral stent.
• Persistent hematuria may signal an AV malformation or pseudoaneurysm requiring angioembolization.
• Advise no strenuous activity for 3 months (delayed-bleeding risk), obtain a renal scan or CT at ~3 months to document function, and monitor for hypertension (renal vascular injury/Goldblatt, a Page kidney from parenchymal compression, or a post-traumatic AV fistula).