Kidney Trauma

Kidney (Renal) Trauma

David Ray Velez, MD

Table of Contents

Background
Diagnosis
Treatment
Nonoperative Management (NOM)

Background

Anatomy

  • Gerota’s Fascia: Surrounds the Kidney and Perirenal Fat
  • Renal Hilum:
    • Structures (Anterior-to-Posterior): Vein > Artery > Pelvis
    • MNEMONIC: “VAP”
  • Renal Artery:
    • Right Renal Artery – Travels Posterior to the IVC
    • Left Renal Artery – Shorter
    • *About 25% Receive Accessory Branches Directly from the Aorta
  • Renal Vein:
    • Right Renal Vein – Shorter, without Collaterals
    • Left Renal Vein – Travels Anterior to the Aorta with Multiple Collaterals
      • Branches: Gonadal Vein, Adrenal Vein, and Second Lumbar Vein

The Majority (80-90%) are from Blunt Abdominal Trauma

AAST Kidney Injury Scale (2018 Revision)

Renal Vasculature

Diagnosis

May Be Diagnosed Intraoperatively or on Radiographic Imaging

Unstable: Laparotomy

  • First Perform a FAST (Focused Assessment with Sonography in Trauma) to Confirm Abdominal Source
    • Diagnostic Peritoneal Lavage (DPL) is Rarely Performed but May Be Considered if FAST is Inconclusive
    • Search for Oher Sources if Negative
  • Consider Intraoperative IV Pyelogram (IVP)
    • Historically the Standard Approach for Radiographic Diagnosis but Rarely Used in Modern Practice with the Advent of CT
    • Accuracy is Variable and May Miss Significant Injuries
  • Diffuse Peritonitis Indicates Bowel Injury and Warrants Laparotomy – Diffuse Peritonitis Should Never be Attributed to Solid Organ Injury

Stable: CT Imaging

  • The Gold Standard in Modern Diagnostic Imaging
  • Obtain Delayed/Excretory Phase Images to Evaluate for Collecting System/Ureter Injury that May Be Missed on Early/Vascular Phase Images Alone

Treatment

The Majority of Renal Injuries are Managed Nonoperatively if Hemodynamically Stable

Indications for Renal Surgical Exploration

  • Hemodynamic Instability
  • Active Hemorrhage Requiring Massive Transfusion
  • Renovascular Pedicle Avulsion
  • Ureteropelvic Junction (UPJ) Avulsion
  • Pulsatile or Expanding Hematoma (Seen Intraoperatively)
  • High-Grade Injury – Debated
    • Nonoperative Management Has Higher Rates of Renal Salvage
    • Surgical Management Can Offer Earlier Definitive Control and Minimize Risk of Urinoma/Bleeding

Indications for Angiography and Embolization

  • Transient Responder
  • Active Extravasation (“Blush”)
  • Pseudoaneurysm
  • Arteriovenous Fistula (AVF)

Parenchymal Injury

  • Superficial Laceration: Primary Repair
  • Deep Injuries: Debridement vs. Partial Nephrectomy
    • Partial Nephrectomy is Done by Sharp Guillotine Transection of a Polar Lesion with Closure of Transected Vessels/Collecting System and Capsule Closure Over the Defect (If Able)
  • Nephrectomy May Be Required for Damage Control if Bleeding is Uncontrolled from High-Grade Injury

Renovascular Pedicle Injury

  • Active Extravasation/Pseudoaneurysm on CT: Angioembolization
  • Active Bleeding at Laparotomy:
    • Primary Repair Preferred
    • May Need to Ligate Segmental Branches – Results in Distal Ischemia, But Preferred Over Nephrectomy
    • Nephrectomy May Be Required for Damage Control
  • Renal Artery Occlusion/Devascularization:
    • Unilateral (Two Normal Kidneys) – Conservative vs Endovascular Management
    • Unilateral (Solitary Kidney) or Bilateral – Surgical Revascularization
  • *Left Renal Vein Can Be Ligated Distally (Close to IVC) Due to High Collaterals
    • Right Renal Vein is Too Short and Lacks Collaterals
  • Maximum Clamp (Warm Ischemia) Time: 20-30 Minutes

Urinary Collecting System Injury

  • Urinary Leak: Nonoperative Management
    • Consider Stent or Nephrostomy if Fails
  • Ureteropelvic Junction (UPJ) Avulsion: Surgical Repair
    • Always Use Absorbable Monofilament Suture (Avoid Stricture/Stones)

Renal Exposure

  • Consider Exposure and Control of the Renal Pedicle Prior to Renal Exploration – May Decrease Nephrectomy Rates
  • Enter the Retroperitoneum by Ipsilateral Medial Visceral Rotation by Mobilizing the Ipsilateral Colon/Mesocolon After Incising the Peritoneal Reflection/Line of Toldt
  • Expose the Kidney Through a Vertical Incision Over the Anterior Surface of Gerota’s Fascia

Nonoperative Management (NOM)

The Exact Definitions for Nonoperative Management are Poorly Defined

Admission

  • Consider ICU Admission for 24-72 Hours for Injuries ≥ Grade III
  • Consider an Initial NPO Status for up to 24 Hours if Closely Monitoring
  • Exact Hospital Length of Stay is Poorly Defined

Activity Restrictions

  • Bed Rest for 24-72 Hours or Until Gross Hematuria Resolves for Significant Injuries
  • Return to Normal Activity After 2-3 Months

Start DVT Prophylaxis Early (Within 24-48 Hours) for Solid Organ Injury if Otherwise Clinically Appropriate

For Grade IV/V Injuries: Repeat CTA After 2-7 Days to Look for Pseudoaneurysm, Arteriovenous Malformation, Urinary Extravasation, or Urinoma

  • Early Diagnosis Allows Prompt Treatment Before Development of Associated Complications
  • Routine CTA is Less Controversial than with Other Solid Organ Injuries (Liver/Spleen)