Jillian Rork, MS III
Gillian Lieberman, MD
February 2011
Arteriovenous Fistulas:
Complications of a Gunshot Wound
Jillian Rork, Harvard Medical School, MSIII
Gillian Lieberman, MD
Jillian Rork, MS III
Gillian Lieberman, MD
Goals of the Presentation
With the help of our index patient, we will:
1) Review the vascular anatomy of the lower extremity
2) Learn the diagnostic tests available to evaluate for
extremity vascular trauma
3) Generate a differential diagnosis of lower extremity
vascular pathology in the setting of trauma
4) Learn the radiologic findings of extremity vascular
trauma on CT angiogram.
5) Learn the limitations of CT angiogram in assessing
vascular trauma
2
Jillian Rork, MS III
Gillian Lieberman, MD
Index Patient Presentation
•
HPI: 21 yo M s/p gun shot wound to the left
upper medial thigh with no exit wound. Absent
PT/DP pulses at the scene.
•
ROS: Pain at entry site. Denies pain and numbness
in left calf and foot. All other systems are normal.
•
•
•
PMH: Bipolar Disorder, Attention Deficit Disorder
Medications: None
Allergies: Morphine
3
Jillian Rork, MS III
Gillian Lieberman, MD
Index Patient: Physical Exam
T: 98.8 HR: 83 BP:145/72 RR: 22 O2 sat: 100%
•
•
•
•
Neuro/Psych: A&O x3, NAD
Cardiac: Regular rate & rhythm, no m/r/g
Pulmonary: Clear to auscultation, normal effort
Extremities:
•
Entry wound in left medial thigh, no exit wound
•
Pulses: RLE femoral, popliteal, PT and DP – Palpable
•
•
•
LLE femoral popliteal, PT and DP – Palpable
No femoral bruit/thrills
No lower extremity edema, compartments soft
Strength and sensation intact bilaterally
4
Jillian Rork, MS III
Gillian Lieberman, MD
Clinical Questions
With an overall benign exam, does our patient need
further evaluation for vascular trauma?
What are the clinical signs of arterial injury in
extremities?
5
Jillian Rork, MS III
Gillian Lieberman, MD
Clinical Signs of Arterial
Injuries in the Extremities
Clinical Signs of Arterial Injures in Extremities
-Clinical signs of
arterial injuries are
divided into Hard Signs
and Soft Signs
-Our patient merits
further workup since
his injury is near
major vessels – the
femoral artery and vein
Hard Signs
Soft Signs
* Absent or diminished
pulses
* Active hemorrhage
* Large expanding or
pulsatile hematoma
* Bruit/thrill
* Distal ischemia
* Small stable hematoma
* Unexplained hematoma
* Injury to an anatomically
related nerve
* Proximity of an injury to
a major vessel
Compton C, Rhee R. Peripheral vascular trauma. Perspect Vasc Surg Endovasc Ther 2005; 17: 297-307.
6
Jillian Rork, MS III
Gillian Lieberman, MD
Clinical Signs of Arterial Injuries in the
Extremities: Pulse or No Pulse
While it is important to remember the hard and soft clinical signs of
arterial injuries, a major take away point from our patient is:
Palpable pulses does NOT exclude vascular injury
7
Jillian Rork, MS III
Gillian Lieberman, MD
Objectives of Imaging Our Patient
The objectives of imaging our patient is to assess the following:
What is the path of the projectile?
 Is there osseous and/or soft tissue injury?
 Is there vascular trauma?

Continue to the next slide for a discussion of
possible imaging modalities
Wilson, A. Gunshot Injuries: What Does a Radiologist Need to Know? Radiographics. 1999 Sept-Oct; 19(5): 1358-68.
8
Jillian Rork, MS III
Gillian Lieberman, MD
Menu of Imaging Tests





Plain film
 Reveals osseous fractures that could jeopardize adjacent vessels, but not
vasculature itself
Ultrasound (US)
 Color-flow duplex scanning demonstrates the integrity of vessels and flow
velocity/directionality; however, US is extremely operator dependent
Conventional angiography
 Identifies vascular injury and has interventional capacity; however, this is an
invasive procedure and does not provide information regarding the foreign
body pathway or osseous/soft tissue structures
X-ray Computed Tomography (CT) Angiogram
 Identification of vascular injury, osseous damage, and foreign body location
MRI
 Identification of vascular injury and soft tissue damage; however, this is an
expensive, more time-consuming imaging modality
Despite the broad menu, CTA is the test of choice for our patient.
Continue onto the next slide to learn more about CTA versus conventional arteriography
9
Jillian Rork, MS III
Gillian Lieberman, MD
Conventional Angiography vs CTA

Studies comparing CTA of the extremities with conventional
angiography have found CTA to be:
 Comparable in accuracy
 More time-efficient
 Less invasive
 Less expensive

Literature Highlight: In a prospective study of 139 patients, CT
angiography was used as the initial imaging modality in the
setting of trauma to the extremities


Sensitivity 95.1% for proximal arterial injuries in the upper and
lower extremities
Specificity 98.7% for proximal arterial injuries in the upper and
lower extremities
Soto JA, Munera F, Morales C, et al. Focal arterial injuries of the proximal extremities: helical CT arteriography as the initial method
of diagnosis. Radiology. 2001; 218: 188-194.
10
Jillian Rork, MS III
Gillian Lieberman, MD
Before reviewing our patient’s CTA images, it is
imperative we review lower extremity vascular
ANATOMY
Images modified from Hansen, JT. Hansen: Netter’s Clinical Anatomy, 2nd Edition. Philadelphia, PA: Saunders Elsevier; 2010.
www.medconsult.com. Date accessed 2/15/11.
11
Jillian Rork, MS III
Gillian Lieberman, MD
Lower Extremity Arterial Vasculature
The “Must Know” Arteries
Femoral Artery
•Superficial femoral artery
•Deep artery of thigh
Popliteal Artery
Anterior tibial artery
Posterior tibial artery
Fibular artery
Image modified from Hansen JT. Hansen: Netter’s Clinical Anatomy, 2nd Edition. Philadelphia, PA: Saunders Elsevier; 2010.
www.medconsult.com. Date accessed 2/15/11.
12
Jillian Rork, MS III
Gillian Lieberman, MD
Posterior Crural Compartment:
Artery Names and Locations
Medial
Lateral
o The popliteal artery divides into
the anterior tibial and the
posterior tibial artery
o The posterior tibial artery gives
rise to the fibular artery
o The posterior tibial artery
courses medially while fibular
artery courses laterally
Posterior Crural Compartment
Image modified from Hansen, JT. Hansen: Netter’s Clinical Anatomy, 2nd Edition. Philadelphia, PA: Saunders Elsevier; 2010.
www.medconsult.com. Date accessed 2/15/11.
13
Jillian Rork, MS III
Gillian Lieberman, MD
Anterior Crural Compartment:
Artery Names and Locations
Lateral
Medial
The anterior tibial descends
and gives rise to the dorsalis
pedis artery
The perforating branch of
fibular artery supplies the
lateral malleolus
Anterior Crural Compartment
nd
Image modified from Hansen JT. Hansen: Netter’s Clinical Anatomy, 2
www.medconsult.com. Date accessed 2/15/11.
Edition. Philadelphia, PA: Saunders Elsevier; 2010.
14
Jillian Rork, MS III
Gillian Lieberman, MD
Vascular Anatomy of Anterior Thigh
Compartment
Lateral
Medial
Superficial and deep femoral
arteries and veins travel through
the anterior compartment of the
thigh (outlined in purple)
*Remember: Keep this image in mind
when reviewing our patient’s axial
CTA images !
Image modified from Hansen, JT. Hansen: Netter’s Clinical Anatomy, 2nd Edition. Philadelphia, PA: Saunders Elsevier; 2010.
www.medconsult.com. Date accessed 2/15/11.
15
Jillian Rork, MS III
Gillian Lieberman, MD
Vascular Anatomy of Crural
Compartments
Lateral
Medial
Anterior Compartment (Purple)
-Anterior tibial artery and vein
Posterior Compartment (Teal)
-Posterior tibial artery and vein
-Fibular artery and vein
Lateral Compartment (Yellow)
-None
*Remember: Keep this image in mind when reviewing our patient’s axial CTA images !
Image modified from Hansen JT. Hansen: Netter’s Clinical Anatomy, 2nd Edition. Philadelphia, PA: Saunders Elsevier; 2010.
www.medconsult.com. Date accessed 2/15/11.
16
Jillian Rork, MS III
Gillian Lieberman, MD
Index Patient: Pelvic CTA Image
Axial CTA of the pelvis shows TWO contrast enhanced vessels (femoral artery and
femoral vein) on the patient’s left side. The patient’s right side shows only ONE
contrast enhanced vessel (femoral artery).
Blue Arrow: Femoral Artery
Right
PACS, BIDMC
Yellow Arrow: Femoral Vein
Left
17
Jillian Rork, MS III
Gillian Lieberman, MD
Index Patient: Pelvic CTA Interpretation
If the CTA was timed properly, only the arteries should be filled with
contrast. Thus, either our test is faulty OR our patient has a connection
between an artery and vein in his left lower extremity, causing contrast to
enter the venous system.
Blue Arrow: Femoral Artery
Yellow Arrow: Femoral Vein
18
Jillian Rork, MS III
Gillian Lieberman, MD
Index Patient CTA: IV Contrast in Superficial Femoral Vein
As we continue down our patient’s leg, we note the bifurcation of the femoral artery
into the superficial femoral artery and deep femoral artery. We also note contrast in the
superficial femoral vein
Blue Arrow = Superficial Femoral Artery
Purple Arrow = Deep Femoral Artery
Yellow = Superficial Femoral Vein
PACS, BIDMC
19
Jillian Rork, MS III
Gillian Lieberman, MD
Index Patient CTA: Arteriovenous Fistula
As we continue down the axial CTA, we notice a stream of contrast between the
superficial femoral artery and vein. This is suggestive of an arteriovenous (AV) fistula
between the artery and vein, which would explain why veins contain contrast
Orange Arrow = Fistula between Superficial Femoral Artery and Vein
PACS, BIDMC
20
Jillian Rork, MS III
Gillian Lieberman, MD
Index Patient CTA: Thrombus/Intimal Flap
This axial CTA of the lower extremity distal to the AV fistula shows an opacity
in the superficial femoral vein, suggestive of either a clot or intimal flap.
Yellow Arrow = Clot or Intimal Flap
In addition, please note the increased diameter of the left thigh,
suggestive of internal hemorrhage and soft tissue swelling
PACS, BIDMC
21
Jillian Rork, MS III
Gillian Lieberman, MD
Index Patient CTA: Foreign Body
Distal to the AV fistula, we find a foreign body – the bullet. Please note
the streak artifact created by the foreign body; this will be important
when discussing the limitations of CTA studies.
Purple Arrow = Bullet
PACS, BIDMC
22
Jillian Rork, MS III
Gillian Lieberman, MD
Index Patient CTA: Popliteal Arteries
As we continue down the lower extremity CTA, we note both popliteal arteries contain
contrast, suggesting adequate perfusion distal to the AV fistula.
No veins contain contrast on this image
Blue Arrow = Popliteal Artery
PACS, BIDMC
23
Jillian Rork, MS III
Gillian Lieberman, MD
Index Patient CTA: Crural Perfusion
This lower extremity axial CTA shows all three vessels of the calf (posterior tibial,
anterior tibial, and fibular artery) contain contrast, suggesting adequate perfusion
and thus decreased risk of ischemic limb. Remembering the crural compartments
make it easier to determine the location of the three arteries.
Pink Arrow = Posterior Tibial
Artery
Anterior
Compart
Blue Arrow = Fibular Artery
Yellow Arrow = Anterior Tibial
Artery
Lateral
Compt
Posterior Compart
PACS, BIDMC
24
Jillian Rork, MS III
Gillian Lieberman, MD
Causes and Complications
of Arteriovenous Fistulas




Cause
 Simultaneous injury of an adjacent artery and vein
Mechanism
 Venous pressure is lower than arterial pressure; thus,
arterial contents will flow into the venous system
 Flow through an arteriovenous fistula is continuous
Physical exam
 Accentuation of the bruit and thrill detected over
fistula during systole
Long-standing complications
 Venous congestion
 High-out cardiac failure
Hemmila MR, Wahl WL, “Chapter 13. Management of the Injured Patient.” Doherty GM.: CURRENT Diagnosis & Treatment :
Surgery, 13th Edition: http://www.accesssurgery.com/content.aspx?aID= 5212736
25
Jillian Rork, MS III
Gillian Lieberman, MD
Comparison Patient 1:
Subacute Arteriovenous Fistula
• This volume-rendered CT angiogram shows an
AV fistula between anterior tibial artery and vein
(long arrow)
• The anterior tibial artery is enlarged above the
level of arteriovenous fistula and smaller distally
(short arrows)
• Dilated veins are shown throughout image,
suggesting a subacute or chronic process
• Retained BB pellet indicated by short arrow
Gakhal MS, Sartip KA. CT angiography signs of lower extremity vascular trauma. Am J Roentgenol. 2009 Jul; 193 (1): W49-57. 26
Jillian Rork, MS III
Gillian Lieberman, MD
CTA Signs of Arterial Injury
In addition to AV fistuals, CTA can show other signs indicative of arterial injury:



Extravasation of contrast material
Pseudoaneurysm
Vessel caliber reduction




Spasm
Dissection or partial-thickness wall injury
External compression
Thrombus/Intimal Flap
On the following slides, we will show examples of each
27
Jillian Rork, MS III
Gillian Lieberman, MD
Comparison Patient 2
Extravasation on CTA
• On this coronal CTA of the right lower
extremity, note the active contrast extravasation
(large arrow) from the superficial femoral artery
• This sometines described as a ‘contrast blush’
• A small hole measuring approximately 1mm
was discovered during surgery and repaired with
primary sutures
Gakhal MS, Sartip KA. CT angiography signs of lower extremity vascular trauma. Am J Roentgenol. 2009 Jul; 193 (1): W49-57.
28
Jillian Rork, MS III
Gillian Lieberman, MD
Comparison Patient 3:
Pseudoaneurysm on Angiogram
• Pseudoaneurysms are leaks contained by
surrounding tissues and local fibrosis
•Simply said: A contained rupture
• Pseudoaneurysm wall is NOT formed by
vascular tissue, but develops from organized
thrombus, associated fibrosis, and
surrounding tissues
Selective mesentric angiogram showing a
pseudoanuerysm related to the left gastric artery
Imaged modified from Windsor JA, Schweder P, “Chapter 37. Complications of Acute Pancreatitis.” Zinner MJ, Ashley SW:
Maingot’s Abdominal Operations, 11th Edition: http://www.accesssurgery.com/context.aspx?aID=130125.
29
Jillian Rork, MS III
Gillian Lieberman, MD
Comparison Patient 4:
Pseudoaneurym on CTA
This volume-rendered CTA
and reformatted coronal CTA of
the right lower extremity show a
small pseudoaneurysm arising
from the proximal anterior tibial
artery (arrows).
Gakhal MS, Sartip KA. CT angiography signs of lower extremity vascular trauma. Am J Roentgenol. 2009 Jul; 193 (1): W49-57.
30
Jillian Rork, MS III
Gillian Lieberman, MD
Comparison Patient 5:
Vessel Caliber Reduction
A
B
Image A: Sagittal reformatted CT angiographic image of lower extremity shows loss of opacification of popliteal
artery (white arrow).
Image B: Conventional arteriogram confirms loss of opacification of popliteal artery suggestive of transection (black
arrow).
Miller-Thomas MM, West OC, Cohen AM. Diagnosing traumatic arterial injury in the extremities with CT angiography: pearls and pitfalls.
Radiographics. 2005 Oct; 25 (Suppl1):S133-42.
31
Jillian Rork, MS III
Gillian Lieberman, MD
Comparison Patient 6:
Vessel Caliber Reduction
Coronal and sagittal CTA of lower extremity showing focal lumen narrowing of left popliteal artery.
During surgical exploration, an intimal flap was found at this site and repaired.
Gakhal MS, Sartip KA. CT angiography signs of lower extremity vascular trauma. Am J Roentgenol. 2009 Jul; 193 (1): W49-57.
32
Jillian Rork, MS III
Gillian Lieberman, MD
CTA Imaging Shortcomings

Poor arterial opacification





Transit of contrast bolus and timing of image
Vessel underfilling from injury or poor
cardiovascular health
Atherosclerosis
Displaced fracture fragments
Artifacts from metal/foreign body
Streak artifacts are the major limiting factor
Please proceed to next slide for example
Gakhal MS, Sartip KA. CT angiography signs of lower extremity vascular trauma. Am J Roentgenol. 2009 Jul; 193 (1): W49-57.
33
Jillian Rork, MS III
Gillian Lieberman, MD
Example of Streak Artifacts
Non-diagnostic CTA with metallic streak artifact after shotgun
injury to the lower extremity
Miller-Thomas MM, West OC, Cohen AM. Diagnosing traumatic arterial injury in the extremities with CT angiography: pearls and
34
pitfalls. Radiographics. 2005 Oct; 25 (Suppl1):S133-42.
Jillian Rork, MS III
Gillian Lieberman, MD
Index Patient: Surgical Intervention

Patient underwent repair of arteriovenous
fistula:




Evidence of through-and-through injury to both
the artery and vein with subsequent fistula
formation
Vein: Following debridement, 2-inch segment of
left greater saphenous vein used to patch
femoral vein
Artery: More than 70% had been transected;
surgeons divided artery in half and mobilized it
to allow for primary reanastomosis
Small strip of vastus medialis muscle (1.5cm x
6cm) was interposed between two repair
vessels to prevent re-fistulization
35
Jillian Rork, MS III
Gillian Lieberman, MD
Index Patient: Post-operative Ultrasound
US color doppler images show no evidence of left superficial femoral arteriovenous
fistula; red and blue colors indicate flow in opposite direction and do NOT mix.
There is no other evidence of other abnormalities in the vessels.
PACS, BIDMC
36
Jillian Rork, MS III
Gillian Lieberman, MD
Conclusions
With the help of our index patient, we have:
1) Reviewed the vascular anatomy of the lower extremity
2) Learned the clinical indications for vascular imaging in the setting of a trauma
- Palpable distal pulses is NOT enough to exclude vascular injury
3) Learned that CT angiogram is a sensitive and specific test to evaluate for extremity
vascular trauma
- Limitations include poor arterial opacification and streak artifacts
4) Learned the radiologic findings of extremity vascular trauma on CT angiogram
- Contrast extravasation
-Vessel caliber reduction
- Pseudoaneurysm
- Arteriovenous fistula formation
37
Jillian Rork, MS III
Gillian Lieberman, MD
Bibliography
BIDMC PACS and Online Medical Records
Compton C, Rhee R. Peripheral vascular trauma. Perspect Vasc Surg Endovasc Ther 2005; 17: 297307.
Gakhal MS, Sartip KA. CT angiography signs of lower extremity vascular trauma. Am J Roentgenol.
2009 Jul; 193 (1): W49-57.
Hansen, JT. Hansen: Netter’s Clinical Anatomy, 2nd Edition. Philadelphia, PA: Saunders Elsevier;
2010. www.medconsult.com
Hemmila MR, Wahl WL, “Chapter 13. Management of the Injured Patient.” Doherty GM.: CURRENT
Diagnosis & Treatment : Surgery, 13th Edition: http://www.accesssurgery.com/content.aspx?aID=
5212736.
Miller-Thomas MM, West OC, Cohen AM. Diagnosing traumatic arterial injury in the extremities with CT
angiography: pearls and pitfalls. Radiographics. 2005 Oct; 25 (Suppl1):S133-42.
Soto JA, Munera F, Morales C, et al. Focal arterial injuries of the proximal extremities: helical CT
arteriography as the initial method of diagnosis. Radiology. 2001; 218: 188-194.
Wilson, A. Gunshot Injuries: What Does a Radiologist Need to Know? Radiographics. 1999 Sept-Oct;
19(5): 1358-68.
Windsor JA, Schweder P, “Chapter 37. Complications of Acute Pancreatitis.” Zinner MJ, Ashley SW:
Maingot’s Abdominal Operations, 11th Edition:
http://www.accesssurgery.com/context.aspx?aID=130125.
38
Jillian Rork, MS III
Gillian Lieberman, MD
Acknowledgements
Gillian Lieberman, MD
James Knutson, MD
Karen Lee, MD
David Li, MD
Emily Hanson
39