Dispelling a stubborn myth, researchers at Johns
Hopkins have shown that children with strokes, brain tumors
and other cerebrovascular diseases can safely undergo a
potentially life-saving brain-mapping test that many
doctors have long shunned over concerns for side
effects.
Analysis of 241 cerebral angiograms performed on 205
children at the
Johns
Hopkins Children's Center between 1999 and 2006 showed
that not a single patient suffered complications during or
immediately following the procedure.
Results of the analysis, believed to be the first
study in more than 25 years to look at the safety of
cerebral angiographies in children, are reported in the
October issue of Stroke.
Performed by threading a catheter into the patient's
groin, through the abdomen and the chest and upward into
the arteries of the neck, cerebral angiography is the most
accurate brain-vessel imaging technique available and a
critical diagnostic and treatment tool, said Lori Jordan, a
pediatric neurologist at the Children's Center and a
co-author of the report.
Philippe Gailloud, senior author of the study and an
interventional neuroradiologist at Johns Hopkins, said,
"The assumption that angiographies in children are more
dangerous than in adults has persisted over the years,
mostly due to lack of evidence. When we ask parents to sign
consent for an angiography, their first question is [about]
how safe it is, and up until now, we didn't have any hard
data to show them," he said. "Given the very low risk of
complications we see, pediatric neurologists should not
hesitate to order the procedure, and we can say to them
that we have research showing this procedure is indeed very
safe in children."
The most dreaded complication of the procedure is
accidental damage to a blood vessel that can cause a
stroke.
"This is an invasive procedure, so obviously
physicians must be careful in determining how appropriate
it is in a child, but as doctors, we should keep in mind
that we shouldn't deny the potentially crucial assistance
of an invasive procedure because of overblown assumptions
of danger," Gailloud said.
Delayed diagnosis and treatment are also dangerous,
and sometimes fatal, Gailloud noted, particularly in cases
of ischemic stroke caused by a clot or lack of blood supply
to the brain vessels; hemorrhagic stroke, caused by a
ruptured brain vessel that bleeds into the brain; and brain
tumors and certain types of malformations of blood vessels
in the brain, which also may rupture and bleed. "An
angiogram is absolutely critical when a child has suffered
an unexplained bleeding in the brain," he said.
Among those studied, a single death occurred three
hours after an angiogram and was attributed to bleeding in
the brain that the patient had suffered before admission to
the hospital, the Johns Hopkins team said. None of the
patients developed blood clots in the groin, a common and
potentially dangerous complication of puncturing the
femoral artery, and none reported leg pain, difficulty
walking or limping during an average follow-up of 28
months.
While most angiograms are diagnostic, they can also be
used to treat spinal and brain malformations endovascularly
— or from within the blood vessel — and thus
offer a less-invasive alternative to neurosurgery for
certain conditions.
In some cases, diagnosis is possible with noninvasive
imaging tests such as CT scans or magnetic resonance
imaging, but these tests can give false-positive or
false-negative results, meaning they would diagnose a
problem where there is none or fail to detect one.
"Unfortunately," Jordan said, "we don't know how often
noninvasive tests are missing or misdiagnosing something.
We do know that angiography is clear."
Compared to doing the test in adults, the procedure in
children usually takes less time because the young patients
have fewer other medical conditions that might cause
complications, Jordan added. In addition, technological
advances over the past 20 years, such as smaller, softer
catheters and guided imagery, also make angiograms in
children safer than they once were.
Each year, strokes are suffered by about 3,200
children, up to half of whom develop permanent cognitive or
motor disabilities; about one-third will have another
stroke, and up to one-fifth will die. Risk factors for
stroke in children include heart disease, sickle-cell
anemia, some blood-clotting disorders, vascular
malformations and viral infections, such as varicella, HIV
and others.
Other investigators in the study include first author
Ingrid Burger, Kieran Murphy and Rafael Tamargo, all of the
Johns Hopkins School of Medicine.
GO TO