Renal TraumaALMUMTIN, AHMED

Introduction

Classification of renal injury.

Mechanisms of injury.

Evaluation.

Treatment.

Complications.

1-5% of trauma patients.

4.9 injuries/100,000.

Kidney is the most commonly injured.

82-95% is by blunt trauma.

Most commonly encountered youth, and male gender. 75% in those < 44 years.

Most pediatric renal injuries result from sporting activities.

Higher grade injuries occur in the setting of MVA , or falls.

Some congenital renal anomalies predispose the pediatric kidney to injury.

The American Association for the Surgery of Trauma scale for renal injury. (AAST).

Blunt Trauma.

50% have associated other injuries

MVA 70%, falls 22%, Pedestrian 5%

Frontal impact > kidney collides with abdominal wall or ribs > acceleration towards the opposite end (secondary collide)

Lateral impact > direct compression of the kidney mostly between fracture ribs and lumbar vertebrae

Uretropelvic junction / renal pedicle usually result from deceleration.

Generally, present with hematuria.

25-50% of UPJ and renal pedicle > no hematuria.

Moderate > stretching of vessels > may result in arterial +/- venous thrombosis

Sever force may cause avulsion of the pedicle.

Penetrating trauma:

Represent 16% of renal injuries.

Firearms 58%, Stab wounds 42%

Patients with penetrating trauma, are more likely to have renal injuries.

Careful assessment of penetrating injury in term of speed, energy kinetics, and location.

Penetrating injuries anterior to anterior axillary line > more likely to result in higher grade injuries.

Flank wounds posterior to the anterior axillary line, result in lower grade, more peripheral parenchymal injuries.

Initial evaluation:

ATLS protocol. ( ABCDE )

Look for the urethra, perineum, flank for ecchymosis or visible bleeding.

Look for seat belt sign > it indicates significant trauma.

Send urine for analysis (microscopic hematuria)

Indications for imaging:

Depend on the severity and mechanism, presence of hematuria (micro/gross), presence of shock (SBP < 90 mmHg).

Combination of blunt trauma + Micro or gross hematuria + shock > imaging.

Blunt trauma + microscpic hematuria + stable > can be observed UNLESS major acceleration/deceleration injury (fall from hight) or High speed MVA.

Blunt trauma + Gross hematuria even if stable > imaging.

All penetrating injuries should be evaluated radiographically.

CT contrast, with 10-minute delayed scan is the GOLD STANDARD.

If no perinephric, periuretric, or pelvic fluid collection, no need for delayed CT.

Repeat imaging 48-72 hours for conservatively managed patients is not required for grade 1,2 and 3 without hemodynamic instability.

Repeating images in grade 4,5 without clinical indication (e.g. sepsis, unstable BP, increasing hematuria or oliguria ) rarely change the management.

IV- Urography:

almost entirely replaced by CT in stable patients.

has a rule in unstable patients who are directly taken for O.R. its helpful in verifying the presence of another functional kidney.

FAST: is used to assess fluid collection, low sensitivity for detecting renal injuries.

A- Non-operative:

To reduce the risk of nephrectomy

Used to treat grade III and IV in stable patient.

patients with mil-moderate trauma who underwent renal exploration > twice the risk of developing a complication (7.1% vs 3.3%)

Signs of failure of conservative management:

Absence of contrast material in the ipsilateral ureter.

Large separation between upper and lower poles.

Multiple areas of extravasation.

Larger transfusion requirements.

No association between diameter/location of extravasation and failure of conservative management.

Retrograde ureteral stenting is advocated in:

Patients with pain from uretral clot obstruction (by CT).

Fever > 38.5

Significant urine leakage on repeat CT 3-5 days later (increasing urinoma).

In hemodynamically stable patient, in the abscence of peritoneal signs:

Obligatory exploration of penetrating renal trauma is decreasing (initially with stab wounds and now with GSW)

B- Operative management:

Absolute indications:

life threatening hemorrhage that is suspected to be of renal cause.

renal pedicle avulsion.

Expanding pulsatile or uncontained retroperitoneal hematoma.

– Relative indications:

• Incomplete radiographic staging.

• Presence of concurrent injuries that require repair/exploration.

• Extensive devitalized renal parenchyma

• Urinary extravasation

• Consider nephrectomy / hemostatic intervention after renal trauma in:

• Patients with sock or those who require high 24-h transfusion rates.

• Those with penetrating injury.

• Higher grade laceration.

• Embolization:

– effective for renal hemorrhage after blunt or penetrating trauma esp after failed conservative management.

– Embolization should be the initial management for patients with:

– Grade 3 & 4 lacerations

– Arteriovenous fistula

– Pseudoanurysm with persistant bleeding.

Left grade III renal laceration, and concomitant grade II splenic laceration

• extravasation/urinoma: higher after penetrating injury, usually with grade IV, V, 75-90% resolve spontanuously.

• Arteriovenous fistula: rare (0-7%), usually after penetrating injury, embolization is the treatment of choice

• Pseudoanurysm formation: mostly occur after penetrating injury. embolization is the treatment of choice

• Secondary hmg: serious, occur 2-3 weeks after penetrating deep lacerations caused by rupture of AV fistula or pseudoaneurysm. embolization is the treatment of choice

• Hypertension

• Thank You