Retroperitoneal Trauma - Complete Oral Exam Guide

Sources: Maingot's Abdominal Operations | Fischer's Mastery of Surgery 8e | Sabiston Textbook of Surgery | Current Surgical Therapy 14e | Mulholland & Greenfield's Surgery 7e

1. ANATOMY OF THE RETROPERITONEUM

Structures contained:

• Vascular: Abdominal aorta + all branches, IVC + tributaries, iliac vessels
• Solid organs: Kidneys, adrenal glands
• Hollow organs (secondary retroperitoneal): Duodenum (2nd, 3rd, 4th parts), ascending and descending colon, rectum, bladder (extraperitoneal portion)
• Other: Pancreas, ureters, lymphatics, sympathetic chains, lumbar plexus

2. THE THREE ZONES OF THE RETROPERITONEUM

• Supramesocolic Zone I: Suprarenal aorta, celiac axis, proximal SMA, suprarenal IVC, proximal SMV
• Inframesocolic Zone I: Infrarenal aorta, distal SMA, IMA, infrarenal IVC, distal SMV

3. THE GOLDEN RULE OF RETROPERITONEAL HEMATOMA MANAGEMENT

4. MECHANISMS OF INJURY

Penetrating Trauma (Most Common Cause of Vascular Injuries)

• Gunshot wounds (GSWs): cause cavitating wounds due to high-velocity projectiles and associated shockwaves. These typically result in vessel thrombosis along with hemorrhage.
• Stab wounds: direct, lower-energy injury
• All penetrating retroperitoneal injuries require exploration regardless of zone (except Zone IV retrohepatic hematoma)

Blunt Trauma

• Motor vehicle accidents, falls, crush injuries
• Less commonly causes major vascular injury
• Renal injuries are the most common retroperitoneal organ injury from blunt mechanism
• Zone III blunt hematomas are typically from pelvic fractures with dissection of blood superiorly

5. CLINICAL PRESENTATION & DIAGNOSIS

Clinical Signs

• Tachycardia, hypotension, narrowed pulse pressure (hallmarks of hemorrhagic shock)
• Abdominal tenderness, distension, peritonitis
• Grey Turner's sign: Flank ecchymosis (retroperitoneal hemorrhage tracking to flank) - delayed sign
• Cullen's sign: Periumbilical ecchymosis - delayed sign
• Unilateral loss of femoral pulse: Concerning for iliac artery or aortic injury
• Gross or microscopic hematuria: suggests renal or ureteric injury
• Pelvic instability on examination: suggests pelvic fracture with Zone III hematoma
• Seat belt sign

Investigations

• CT scan with IV contrast (triple-phase) is the investigation of choice
  • Arterial phase: identifies arterial bleeding, pseudoaneurysm, occlusion, dissection, AV fistula
  • Nephrogram phase: renal parenchymal injury
  • Delayed/excretory (pyelogram) phase: pathognomonic - contrast extravasation identifies renal pelvis or ureteric injury
  • Also identifies trajectory of GSW

• FAST exam (Focused Assessment with Sonography in Trauma): identifies free fluid but has poor accuracy for diagnosing major vascular trauma
• Diagnostic Peritoneal Lavage (DPL): Rarely used now, but useful in unstable patient with equivocal FAST. Gross blood or succus = immediate laparotomy
• Plain X-ray: Radio-opaque markers (paper clips) to determine GSW trajectory; pelvic fractures

• CBC, type and cross, basic chemistry, lactate, ABG/VBG
• Thromboelastography (TEG): Guides coagulation status and resuscitation

• Useful intraoperatively to confirm presence of contralateral kidney before nephrectomy
• No longer routinely used (hydration-dependent, less detail than CT)
• Still used in unstable patients going directly to OR

6. OPERATIVE MANAGEMENT

Initial Steps (Damage Control Approach)

1. Standard midline laparotomy from xiphoid to pubic symphysis - gives access to all four quadrants
2. Evacuate blood and pack all four quadrants
3. Systematically survey for active bleeding
4. Initial hemorrhage control: Packing + digital pressure, then more extensive exposure for proximal and distal vascular control
5. For arteries: vascular clamps; for major veins: sponge sticks (preferred to avoid tearing thin venous walls)
6. Control enteric injuries with oversewing or bowel clamps to prevent contamination
7. Then proceed to definitive repair based on patient stability

Key Surgical Exposures (HIGH-YIELD for Oral Exam)

MATTOX MANEUVER (Left Medial Visceral Rotation)

• Indication: Supramesocolic Zone I hematoma; aorta and left-sided retroperitoneal structures
• Technique: Incise the white line of Toldt along the descending colon, curving around the spleen and gastroesophageal junction. Rotate left colon, distal pancreas, spleen, stomach fundus, and left kidney medially
• Exposes: Entire abdominal aorta, celiac axis, SMA, left renal artery, IMA, aortic bifurcation and iliac arteries
• Proximal control: Supraceliac aorta clamped at the diaphragmatic hiatus

CATTELL-BRAASCH MANEUVER (Right Medial Visceral Rotation)

• Indication: IVC injuries, right-sided Zone I hematoma, infrarenal vasculature, right renal hilum
• Technique: Take down white line of Toldt along ascending colon + wide Kocher maneuver (mobilize duodenum and pancreatic head medially) + incise small bowel mesentery along ileocecal junction toward ligament of Treitz
• Exposes: Infrarenal IVC, common iliac veins, infrarenal aorta, right renal hilum

KOCHER MANEUVER

• Mobilization of duodenum and pancreatic head to expose retroduodenal structures and right renal hilum

Inframesocolic Zone I Exposure

• Reflect small bowel to the right, transverse colon cephalad
• Take down ligament of Treitz
• Left renal vein is encountered, then infrarenal aorta can be exposed

7. ZONE-SPECIFIC MANAGEMENT IN DETAIL

Zone I Management

• ALWAYS requires exploration (blunt or penetrating)
• Proximal control first - supraceliac aorta clamped at the diaphragm
• If hematoma extends to aortic hiatus: may require surgical control of thoracic aorta or placement of REBOA (Resuscitative Endovascular Balloon Occlusion of the Aorta)
• Supramesocolic: Mattox maneuver
• IVC bleeding (supramesocolic): Right visceral rotation (Cattell-Braasch)
• Inframesocolic: Small bowel reflected right, transverse colon cephalad

Zone II Management

• Penetrating: Always explore - approach depends on side
• Blunt: Selective - explore only if expanding or pulsatile hematoma (signs of arterial injury)
• A rapidly expanding Zone II hematoma or pulsatile hematoma may indicate need for nephrectomy
• Signs that nephrectomy may be indicated: rapidly expanding Zone II hematoma or pulsatile hematoma
• First confirm presence of contralateral functioning kidney (single-shot IVP or CT)

Zone III Management

• Blunt: Do NOT explore - tamponade is protective; exploring destroys the effect and releases retroperitoneal pressure
  • Management: pelvic binders, angioembolization (interventional radiology), pre-peritoneal pelvic packing (PPP)
• Penetrating: Always explore
• REBOA (Zone III) can provide temporary hemorrhage control

8. SPECIFIC ORGAN INJURIES

Renal Injuries (Most Common Retroperitoneal Solid Organ)

• Grade I-III (blunt): Non-operative management (NOM) - bed rest, serial imaging
• Grade IV-V (penetrating): Typically require nephrectomy, especially with viable contralateral kidney
• Interventional radiology (angioembolization) has largely supplanted isolated nephrectomy for segmental arterial bleeding
• Unstable patients with active bleeding from kidney/renal hilum: operative intervention
• Renorrhaphy: For lacerations/superficial wounds - approximate disrupted capsule with pledgeted sutures or prosthetic (mesh) wrap, drain all repairs
• Partial nephrectomy: When injury pattern permits

• CT with IV contrast (triple phase)
• Hematuria on UA: even children (<16 years) should undergo CT urogram if >50 RBC/HPF
• Renal vein injuries have lowest detection sensitivity on CT of all hilar structures - be vigilant

Ureteric Injuries

• Subtle, often missed
• Identified on the delayed phase of CT (contrast extravasation = pathognomonic of renal pelvis or ureteric injury)
• Gross hematuria, urinoma, or hydronephrosis may suggest ureteric injury
• Intraoperative: Cystoscopy + retrograde pyelogram when suspected and no pre-op imaging
• Primary repair: Interrupted absorbable suture over double-J stent; spatulate ends if complete transection; drain the repair
• If tension-free anastomosis not possible: Boari flap (bladder flap) + psoas hitch
• All ureteric repairs should be adequately drained

Duodenal and Pancreatic Injuries

• Located in Zone I retroperitoneum (2nd, 3rd, 4th portions of duodenum; body/head of pancreas)
• High-energy blunt trauma (handlebar injury, steering wheel) can cause deceleration injury
• Duodenal hematoma: Conservative management (NGT decompression, TPN); operative management if obstruction persists >2 weeks
• Duodenal perforation: Repair + drain; Pyloric exclusion for severe injuries
• Pancreatic injury: Distal pancreatectomy for body/tail; drainage for head injuries

Bladder Injuries

• Extraperitoneal: Most common in pelvic fractures; managed with urinary catheter + bladder decompression. May require operative repair if extensive or if anterior pelvic ring stabilization needed (risk of hardware contamination)
• Intraperitoneal: Classic repair in two-layer fashion with absorbable suture + catheter decompression

Adrenal Injuries

• Usually managed non-operatively
• Bilateral adrenal injuries may require steroid supplementation

9. DAMAGE CONTROL SURGERY IN RETROPERITONEAL TRAUMA

Damage Control Stages:

1. Phase 0 (Pre-hospital): Hemorrhage control, rapid transport
2. Phase I (OR): Abbreviated surgery - control hemorrhage (pack/ligate/shunt), control contamination, close abdomen temporarily
3. Phase II (ICU): Resuscitation - warm, correct coagulopathy with MTP (massive transfusion protocol), reverse acidosis
4. Phase III (Planned re-op): Definitive repair (anastomoses, definitive vascular repair, remove packs)

• Ligation: For vessels that can be sacrificed (e.g., infrarenal IVC, internal iliac)
• Temporary Intravascular Shunt (TIVS): Maintains flow, buys time for resuscitation
• REBOA: Endovascular balloon occlusion at three zones:
  • Zone I REBOA (descending thoracic aorta): For abdominal/pelvic hemorrhage
  • Zone III REBOA (infrarenal aorta): For pelvic hemorrhage

10. PELVIC FRACTURE AND ZONE III HEMORRHAGE

• Open book fracture (AP compression)
• Lateral compression
• Vertical shear (most unstable/deadly)

• 80-85%: Venous plexus + cancellous bone (low pressure, self-tamponading)
• 15-20%: Arterial (superior gluteal artery most common)
• Both together in severe injuries

1. Pelvic binder (immediate - circumferential compression, reduces volume, tamponades venous bleeding)
   • Note: External fixation only provides anterior compression and can paradoxically open the posterior pelvis and worsen hemorrhage
2. Massive Transfusion Protocol (1:1:1 ratio pRBC:FFP:platelets)
3. CT angiography (if hemodynamically stable)
4. Angioembolization (for arterial bleeding on CT) - primary tool for arterial Zone III hemorrhage
5. Pre-peritoneal pelvic packing (PPP): If angioembolization unavailable/unsuccessful and patient remains unstable - pack anterior to peritoneum, tamponade pelvic space
6. Definitive pelvic fixation: Ideally within 12-36 hours once stabilized - improves pulmonary hygiene, early mobilization, hemostasis
7. REBOA (Zone III): As bridge to angioembolization

11. RESUSCITATIVE ENDOVASCULAR BALLOON OCCLUSION OF THE AORTA (REBOA)

• Introduced as adjunct for temporary hemorrhage control in Non-Compressible Torso Hemorrhage (NCTH)
• Used in trauma since the Korean War
• More widespread use in tertiary trauma centers
• Mechanism: Balloon inflated in aorta proximal to injury - redirects blood to heart/brain, reduces distal hemorrhage
• Three zones of deployment:
  • Zone I (descending thoracic aorta, T4-T7): Abdominal and pelvic hemorrhage
  • Zone II (NOT used - too close to renal vessels/visceral aorta)
  • Zone III (infrarenal aorta, L1-L4): Pelvic/junctional hemorrhage
• Role remains controversial in prehospital and ED settings

12. ABDOMINAL VASCULAR INJURIES - HIGH-YIELD SUMMARY

13. LIKELY ORAL EXAM QUESTIONS AND MODEL ANSWERS

14. COMPLICATIONS

• Delayed hemorrhage: Pseudoaneurysm, AV fistula (especially after NOM of renal injuries)
• Urinoma: Post-traumatic urine collection from unrecognized ureteric injury
• Post-traumatic ileus / paralytic ileus: Classic complication of retroperitoneal irritation (blood/urine in retroperitoneum)
• Abdominal compartment syndrome: After massive resuscitation and temporary abdominal closure
• OPSS (Overwhelming Post-Splenectomy Sepsis): If splenectomy performed - vaccinate against pneumococcus, Hib, meningococcus
• Pelvic sepsis: From missed rectal injuries in Zone III penetrating trauma
• DVT/PE: Common after pelvic fractures; anti-coagulation is challenging given ongoing hemorrhage risk

"Zone 1 = Always open (pipes are broken) | Zone 2 = Penetrating always, Blunt only if expanding | Zone 3 blunt = NEVER open (the tamponade is your friend)"

• Maingot's Abdominal Operations, p. 1272
• Fischer's Mastery of Surgery 8e, p. 7069-7076
• Sabiston Textbook of Surgery, p. 988-996
• Current Surgical Therapy 14e, p. 1369
• Mulholland & Greenfield's Surgery 7e, p. 1380