DOI:10.2214/AJR.06.0608
AJR 2007; 188:W306
© American Roentgen Ray Society
Hemolytic Anemia Caused by Iatrogenic Arteriovenous Iliac Fistula and Successfully Treated by Endovascular Stent-Graft Placement
Julie O'Brien,
Orla Buckley and
William Torreggiani
AMNCH, Adelaide and Meath Hospital, Dublin, Ireland
WEB—This is a Web exclusive article.
A 33-year-old man was admitted to our hospital for investigation and
treatment of lower back pain. MRI of the lumbar spine revealed degenerative
change and significant disk protrusion at the L5-S1 level, which was treated
by lumbar diskectomy and laminectomy. Postoperatively, the patient developed
back pain that was managed conservatively, and he was discharged.
He was readmitted 3 months later with lethargy and persisting back
discomfort. Physical examination was unremarkable. Laboratory investigations
revealed anemia with elevated reticulocytes and lactate dehydrogenase (LDH)
with reduced serum haptoglobins, consistent with hemolytic anemia from
intravascular hemolysis.
CT scans revealed indirect evidence of an arteriovenous fistula with
opacification of a distended inferior vena cava in the arterial phase
(Fig. 1A). A conventional
angiogram confirmed the fistula between the right common iliac artery and left
common iliac vein (Fig. 1B).
The fistula developed secondary to the previous spinal surgery because of
inadvertent trauma to the iliac vessels, and the rapid flow within the fistula
resulted in hemolytic anemia. The fistula was subsequently treated with a
covered stent-graft (Fig. 1C)
with successful resolution of the patient's hematologic parameters. The
patient was discharged and remains well.
Hemolytic anemias are generally classified into intravascular and
extravascular hemolysis. In this case, the hemolytic anemia was intravascular
and related to destruction of erythrocytes from high flow through the iliac
fistula. Fistulas usually develop as a result of inflammation or trauma to the
vessel or surrounding tissue. Trauma to the iliac vessels occurred
inadvertently during surgery in this case. Vascular injury during spinal
surgery is a known but unusual complication reported to occur with an
incidence of 0.017% [1].
Retroperitoneal hemorrhage is well documented, but fistula formation is rare.
The precise incidence of this complication is unknown, but one series reported
arteriovenous fistula in 5 of 3,500 cases
[2].
Previously, conventional angiography was necessary to make the diagnosis of
a fistula; however, CT is now performed in the initial assessment of such
patients [3]. CT findings
include early filling and distention of the venous system and direct
visualization of the fistula. Until recently, open surgical repair was the
only treatment, and it had a significant operative mortality. In recent years,
however, covered stent-graft technology has allowed for many fistulas of this
kind to be treated in a minimally invasive fashion
[4]. In the case we have
presented, a covered stent-graft was successful in eliminating the iliac
arteriovenous fistula and, thus, the patient's hemolysis.
References
- DeSaussure RL. Vascular injury coincident to disk surgery.
J Neurosurg 1959;16
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- Hohf RP. Arterial injuries during orthopaedic operations.
Clin Orthop Relat Res 1963;28
: 21-37[Medline]
- Rosenthal D, Atkins CP, Jerrius HS, Clark MD, Matsuura JH.
Diagnosis of aortocaval fistula by computed-tomography. Ann Vasc
Surg 1998; 12:86
-87[CrossRef][Medline]
- Lau LL, O'Reilly MJ, Johnston LC, Lee B. Endovascular stent-graft
repair of primary aortocaval fistula with an abdominal aortoiliac aneurysm.
J Vasc Surg 2001;33
: 425-442[CrossRef][Medline]
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