Pseudoaneurysm of Lower Extremity

Robert Benzl MS4

August 2013

Jordan Tasse MD, Konrad Bienia MD

• 82 y/o female• L THA in 5/2011, c/b periprosthetic fracture, s/p plate fixation,

c/b infection and stem loosening, s/p proximal femoral replacement as single stage revision with chronic suppressive abx therapy on 6/12/2013.

• 7/19/2013, on routine follow up she was noted to have left thigh swelling. Patient stated she had not been taking suppressive antibiotics as recommended. Patient was started on Bactrim.

• 8/2/13, patient presented to OSH for acute onset left thigh pain/swelling/anemia (Hb to 7.8). Pt transferred the night of 8/5/13 to Rush after initial workup and management.

Patient History

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• Labs 8/5/13: – WBC 11.6, Hb 8.7 (s/p 7 units pRBC)– platelets 146,000– INR 1.2, ptt 24.6– fibrinogen 309– D-dimer 21,560 – Creatinine of 1.17

• CXR 8/5/13: wnl• VQ scan 8/2/13: For chest pain. Low probability for PE. • LE Doppler 8/2/13: No DVT.• Angiogram not obtained 2/2 elevated creatinine • CT hip: 8/3/13: Large soft tissue density in post aspect of

thigh 13.9X8.3X30. No fracture.

OSH Findings 8/5/13

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Left Thigh - Mid Diaphysis

CT - Soft Tissue Window - Axial

Left Thigh - Mid Diaphysis

CT - Soft Tissue Window - Axial

• CONSTITUTIONAL: – awake, alert, cooperative, in pain.

• HEENT: – no JVD.

• LUNGS: – Good air entry, no added sounds.

• CARDIOVASCULAR: – Normal S1 & S2, no murmur.

• ABDOMEN: – Soft, nontender.

• L Lower ext: – In neutral position. healed lateral incision from hip along thigh, with

significant surrounding ecchymosis and induration. Warm, tender to palpation. Maximal around hip. Unable to move extremity 2/2 pain. Pulses palpable.

Physical Exam

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• Acute bleed/hematoma • Soft tissue infection• Femur fracture• Arterial aneurysm• Sarcoma

DDx

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Imaging Options

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CT (soft tissue mass) LE Duplex US (negative for DVT) X-Ray Ultrasound MRI Angiography

Imaging

X-Ray FemurMRN 6582667

Imaging

X-Ray Left Femur (distal)MRN 6582667

Major X-Ray positives/negatives: • Soft tissues demonstrate diffuse swelling• Prosthetic components in their expected position. • No periprosthetic fracture distal to the femoral rod.• Periosteal reaction and callus formation and suggestion of a prior oblique

femoral fracture. • No radiopaque foreign bodies.

Next diagnostic modality: Ultrasound (bleed/hematoma highest on ddx).

Imaging Options

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Sample Hematoma Case (not our patient)

There is well-defined collection noted in subcutaneous plane which is compressible.  Lesion is anechoic with thin septa within. Thin but well-formed capsule is seen.

http://radiopaedia.org/cases/soft-tissue-haematoma-of-thigh

soft tissue density

F 70. Blunt trauma to thigh - 15 days. C/o local swelling - 5 days.

X-Ray Ultrasound

Left Lateral Thigh Ultrasound

Heterogeneously echogenic mass within the subcutaneous tissues extending along

the lateral left thigh from just below the hip to the level of the knee.

Left Lateral Thigh Ultrasound

Color Doppler demonstrates no internal vascularity. No communicating vessels are demonstrated. Mass measures at least 20 centimeters in length by 15 cm in transverse dimension.

Imaging Options

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Given clinical picture and diagnostic imaging thus far, there is high suspicion for a bleed into thigh compartment.

Next chosen modality: Angiography – can potentially localize bleed and offer

therapeutic intervention.

Left External Iliac Artery Angiogram

Left External Iliac Artery Angiogram

Left External Iliac Artery Angiogram

Left External Iliac Artery Angiogram

Left External Iliac Artery Angiogram

Left External Iliac Artery Angiogram

Pseudoaneurysm located off of lateral branch from profunda femoris artery.

Left External Iliac Artery Angiogram

Responsible vessel embolized with metallic coils (white arrow).

Pseudoaneurysms

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• Following arterial injury, communication may persist with hematoma and arterial lumen. The resulting hematoma is contained within surrounding soft tissues.

• Commonly found as pulsating soft tissue masses, diagnosed clinically or with color duplex ultrasound.

• Most commonly associated with prior interventional procedure that required arterial access. Incidence is linked in inadequate time of pressure applied for homeostasis following sheath removal.

• In our case, ultrasound study did not show arterial communication with the soft tissue mass, nor was it noted to be pulsating on exam. Angiography did demonstrate communication of arterial lumen with soft tissue space/hematoma.

Follow Up

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• IR drain placement via ultrasound guidance the next day.• Continued improvement, wound cultures NTD.• Patient dc’d to skilled nursing facility.