Download infective endocarditis at bicuspid aortic valve complicated with

Taiwan Crit. Care Med.2009;10:318-325
Sir-Chen Lin et al.
INFECTIVE ENDOCARDITIS AT BICUSPID AORTIC VALVE
COMPLICATED WITH SEVERE AORTIC REGURGITATION AND
RUPTURE OF INTRACRANIAL INFECTIVE ANEURYSM: REPORT
OF A CASE WITH LITERATURE REVIEW
Sir-Chen Lin1, Shih-Chi Liu2,3, Chuen-Den Tseng2
Abstract
Infective endocarditis may complicate with intracranial infective aneurysm,
which carries high mortality rate up to 80% and remain a challenge for critical
care providers. We report a 33-year-old man who initially presented with fever,
exertional dyspnea, heart murmur and transient focal neurologic deficit. Infective
endocarditis over bicuspid aortic valve with severe aortic regurgitation and acute
pulmonary edema was diagnosed. Five days after admission to intensive care unit,
sudden onset of severe subarachnoid hemorrhage happened. Emergent angiography
proved a cerebral aneurysm over left MCA with rupture. Blood culture revealed
growth of methicillin-resistant Staphylococcus aureus. Brain edema and coma
persisted. No further surgical intervention of brain or heart was done due to rapid
downhill clinical course and high perioperative risk. Finally, the patient did not
survive because of septic shock, disseminated intravascular coagulation, and multiorgan failure. We discuss such situation of this patient who had infective endocarditis
complicated with intracranial infective aneurysm. We reviewed the related literature
about the etiology, clinical presentation, diagnosis, clinical prognosis and management.
It is believed that intracranial infective aneurysms are caused by septic emboli from
vegetations. Its incidence accounts for at least 1% among patients with infective
endocarditis. It is estimated that the most common location is the branch of middle
cerebral artery. The prodromes of intracranial infective aneurysms can be insidious,
which make it hard to diagnose. Once the aneurysm ruptures, the clinical prognosis
is poor. It is difficult to decide whether operation should be performed first, brain
or heart, because surgical intervention in this setting is highly risky. Nowadays,
endovascular treatment for intracranial infective aneurysms may serves as an
alternative modality for such complicated case.
Key words: Bicuspid aortic valve, Infective endocarditis, Intracranial infective
aneurysm
Correspondence: Dr. Chuen-Den Tseng
Section of cardiology, department of internal medicine, National Taiwan University Hospital; No. 7, Chung Shan South
Road, Taipei, Taiwan2
Phone: 886-6-231-23456 ext. 63951; E-mail: [email protected]
Department of cardiology, Taipei City Hospital, Renai Branch, No. 10, Jen Ai Road, Sec. 4, Taipei, Taiwan 1
Department of cardiology, Min-Sheng General Hospital, No. 168, Jing Guo Road, TaoYuan, Taiwan3
318
Taiwan Crit. Care Med.2009;10:318-325
Bicuspid aortic valve endocarditis complicated with
ruptured intracranial aneurysm
Case Report
A 33-year-old man came to the emergency
room with chief complaints including progressive
dyspnea on exertion, intermittent high fever for
about 3 months. Right side limbs weakness had
ever happened 4 days ago, but it spontaneously
subsided during 24 hours. He had ever visited
local medical doctors, and only common cold
was told. He denied past history of systemic
diseases such as hypertension or diabetes mellitus,
but he had heavy alcohol consumption.
Physical examination revealed: blood pressure = 102/48, bilateral basal rales breath sound,
grade VI diastolic murmur over right sternal
border. Electrocardiography showed sinus tachycardia and non-specific ST segment change. Chest
X-ray disclosed cardiomegaly with bilateral hilar
infiltration. Room air pulseoximeter saturation
was 88%. Hemogram revealed leukocytosis with
left-shift. Echocardiography revealed: a vegetation 3.0X1.8 cm over the non-calcific bicuspid
aortic valve with protrusion to left ventricle in
diastolic phase (Figs. 1-3), severe aortic regurgitation (Fig. 4), dilated left ventricle with borderline
contractility (ejection fraction = 54%), marked
diastolic reversal of flow in ascending, thoracic
descending and abdominal aorta (Fig. 5).
Under the impression of infective endocarditis,
severe aortic regurgitation with congestive heart
failure, the patient was admitted to intensive care
unit. Then he was intubated with ventilator support
due to aggravated pulmonary edema. Sudden
onset of right side limbs weakness happened the
next day followed by deep coma and episodes
of seizure attack. Brain CT scan revealed diffuse
subarachnoid hemorrhage with brain edema (Figs.
6-7). Emergent angiography was done, which
showed one cerebral aneurysm over left middle
cerebral artery (M1-M2 bifurcation, sized about
4 cm) was demonstrated (Fig. 8). Therefore,
intracranial infective aneurysm rupture was
confirmed. Blood culture revealed methicillinresistant Staphylococcus aureus growth. Antibiotic treatment with vancomycin was given since
the day of admission, but there was still inter-
Fig. 1
Fig. 2
Fig. 3
Fig. 4
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Taiwan Crit. Care Med.2009;10:318-325
Sir-Chen Lin et al.
mittent high fever and persistent leukocytosis.
His brain edema and consciousness disturbance
never improved. Because of fragile consistency
of infective aneurysm, possibility of further embolic
event and poor heart function and unacceptable
high perioperative risk, neither neurology nor
cardiovascular surgical interventioin was planned.
Later on, septic shock, disseminated intravascular
coagulation, with multi-organ failure developed.
The patient expired 14 days after admission.
Fig. 5
Fig. 6
Fig. 7
320
Taiwan Crit. Care Med.2009;10:318-325
Bicuspid aortic valve endocarditis complicated with
ruptured intracranial aneurysm
Fig. 8
Discussion
bicuspid aortic valve stenosis.3 The important
clinical consequences of bicuspid aortic valve
disease are valvular stenosis, regurgitation, infective endocarditis, and aortic complications
such as dilation and dissection.2 The incidence
of infective endocarditis in cohorts of patients
with bicuspid aortic valve is 9.5%.5
The incidence of neurological complications of between 20% and 40% in patients with
infective endocarditis is remained remarkably
constant.6 Neurologic manifestations of infective
endocarditis include TIA, embolic CVA, ruptured
intracranial infective aneurysm, meningitis, seizure,
and nonfocal encephalopathy.7 In published reviews, the frequency of CNS involvement in
patients with endocarditis caused by S. aureus
has ranged from 53% to 71%, higher than the
rates caused by other bacteria. Patients with
infection caused by S. aureus have a significantly
higher incidence of neurologic sequelae and
death.8
Systemic embolization occurs in 22% to
50% of cases of infective endocarditis. Up to
65% of embolic events involve the central nervous
system, and 90% of central nervous system emboli
lodge in the distribution of the middle cerebral
artery. Vegetations >1 cm in diameter are associated with the greatest risk of embolism. 9 Intracranial hemorrhage occurs in about 5% of
We reported an unusual case of infective
endocarditis with intracranial hemorrhage, probably due to ruptured aneurysm with rapid
deterioration. This situation needed early detection and aggressive management.
The bicuspid aortic valve is the most common
congenital cardiac malformation. The prevalence
of bicuspid aortic valve by sex is 7.1/1000 in
male neonates and 1.9/1000 in female neonates.
Bicuspid aortic valve is likely a genetic disorder.
Multiple genes have been implicated including
endothelium-derived nitric oxide synthase gene,
NOTCH 1, and ubiquitin degradation gene. 3
Echocardiographic screening of first-degree relatives is therefore warranted.2 On echocardiography,
aortic valve anatomy can be reliably determined
in a short-axis view. Diastolic images can be
misleading because the raphe in the larger leaflet
of a bicuspid valve may simulate a trileaflet valve
in the closed position.4
Inadequate production of fibrillin-1 during
valvulogenesis may disrupt the formation of the
aortic cusps, resulting in a bicuspid valve and
a weakened aortic root.2 The histopathology of
a bicuspid aortic valve includes inflammation,
fibrosis and calcification. Dyslipidemia appears
to be associated with accelerated progression of
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Sir-Chen Lin et al.
leukocytes, and elevated protein.9 A large series
reported that complaints at the time of admittance
are related to SAH in 32.5%, ICH in 25.5%, while
11% of the cases experienced symptoms such as
headache, seizure and high fever. 16
Cerebral angiography is used if CT reveals
intracranial hemorrhage.7 Some authors suggested
even prodromal signs and symptoms of embolism
in patients with infective endocarditis should be
considered as indicators for cerebral angiography
to detect cerebral bacterial aneurysms before
rupture.17 Four vessel angiography remains the
standard form of investigation and should be
performed if an aneurysm is clinically suspected
even if the CT scan is normal.13 Angiography
is a reliable test to diagnose aneurysm with a
sensitivity of 90%.16 Magnetic resonance angiography seems to have a sensitivity of 86% and
a specificity of 100% for intracranial infective
aneurysms larger than 3 mm in diameter. 8
The overall mortality rate among infective
endocarditis patients with intracranial infective
aneurysms is 60%. Among those without rupture,
the mortality rate is 30%; this approaches 80%
if rupture occurs. 9 Aneurysm rupture is life
threatening, producing subarachnoid hemorrhage,
intracerebral hemorrhage, or direct intracranial
destruction of the brain.18 Aneurysm rupture is
the most important factor affecting the prognosis.16
Management of the intracranial infective
aneurysms is dependent on factors like the presence
or absence of hemorrhage, anatomic location,
their numbers, location, and patients’ clinical
course. Indications for surgical intervention must
be evaluated on individual basis.19 Intracranial
infective aneurysms may heal with medical therapy.
Generally speaking, the duration of antibiotic
treatment is between 4 and 6 weeks in most
patients.16 There is evidence that one-third resolve completely with antibiotic therapy alone.
One-third will demonstrate no significant change
in size. Of the remaining third, half enlarge on
treatment while the other half reduce in dimensions.11 Even if regression of the aneurysm is
observed in cerebral angiographies of the patients
patients with infective endocarditis. There are at
least there different mechanisms of intracranial
hemorrhage : 1) embolic infarcts with secondary
hemorrhagic transformation; 2) acute erosive
arteritis with rupture; and 3) subacute aneurysms
with rupture.10 Anticoagulation is associated with
an increased risk of intracranial hemorrhage and
dose not prevent separation of small fragments
from the infected vegetations. In an experimental
animal model of septic brain embolism, anticoagulation therapy is associated with an increased
risk of hemorrhage.8
It is estimated that cerebral infective aneurysm develops in 1% to 12% of patients with
infective endocarditis and that 10% of these
aneurysms rupture.7 Infected embolic material
may reach the adventitial layer of an artery
through the vasa vasorum; the resulting destruction of the adventitia and muscularis.8 The arterial
pulsation against a weakened wall leads to aneurysm
formation.11 Experiments suggest that intracranial
infective aneurysm usually forms within 48 hours
of embolization.12
The intracranial infective aneurysms most
commonly are located on the peripheral branches
of the middle cerebral artery (55%)13 Near the
surface of the brain, infective aneurysms usually
involve the secondary and tertiary branches,
especially those located in the region of the
Sylvian fissure. 14 Multiple aneurysms are detected with an incidence of 18% to 28% in the
literature.13 The most common morphology is
saccular type.15
The clinical presentation of patients with
intracranial infective aneurysms is highly variable.9
More than 50% of patients with intracranial infective aneurysms have no identifiable prodrome.12
Symptoms of an intracranial infective aneurysm
usually are not evident unless the aneurysm ruptures
or enlarges before rupture and may manifest as
compromised cranial nerve function or as a premorbid phase with headache or nuchal rigidity.8
Some intracranial infective aneurysms leak slowly
before rupture and produce mild meningeal
irritation. Typically, the spinal fluid in these
patients is sterile and contains erythrocytes,
322
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Bicuspid aortic valve endocarditis complicated with
ruptured intracranial aneurysm
tions for valve replacement in patients with bacterial
endocarditis, there is uncertainty regarding the
operative priority in patients with both intracranial aneurysm and acute heart failure. If a
craniotomy for direct clipping is performed first,
perioperative management could be insufficient
to control progressive heart failure. On the other
hand, if valve replacement is selected first,
cardiopulmonary bypass with systemic heparinization could cause lethal neurologic deficits.18
Some patients with infective endocarditis require
both cardiac valve replacement and intracranial
infective aneurysm ligation. Although data are
limited in this situation, an approach that uses
staged procedures, with the more severe problem
dictating the procedure to be performed first, has
been suggested. A bioprosthetic valve, which
does not require anticoagulant therapy, may be
preferable to a mechanical valve in this circumstance.9
In patients whose general condition precludes surgery, a minimally invasive endovascular
approach is used to embolize the aneurysm.8
Detachable balloon technique had been proven
to be a simple procedure for bacterial aneurysms.20
After Guglielmi introduced the detachable platinum coil in 1989, coil embolization has steadily
replaced neurosurgical therapy after publication
of a randomized comparison of endovascular and
surgical treatments of ruptured aneurysms (International Subarachnoid Aneurysm Trial, ISAT).21
Another new technique is injection of N-butylcyanoacrylate glue into the affected aneurysm.11
The decision to use a coil or cyanoacrylate
as an occlusive device depends on the location
of the aneurysm. If the aneurysm can be reached
with a microcatheter, cyanoacrylate is the logical
choice because it permits simultaneous sealing
of the aneurysm. A coil may also be used to
achieve occlusion of the parent vessel, but the
advantage of using detachable coils must be
weighed against the elevated risk of perforating
the inflamed and fragile aneurysmal wall. 22
The major advantage of the endovascular
techniques is that they avoid craniotomy and
surgical handling of the swollen brain. Post-
under antibiotic treatment, the aneurysm may
regrow.16 However, late rupture of intracranial
infective aneurysm after otherwise successful
treatment of infective endocarditis can occur. 10
Unfortunately, there is no way to predict whether
a intracranial infective aneurysm will regress or
rupture on appropriate antibiotic treatment. 11
Surgical excision of peripheral aneurysms is made
easier after antibiotic therapy, because the aneurysm wall is much thicker and less likely to
rupture.13
Patients should undergo neurosurgery for
ruptured aneurysms of cerebral arteries when
intracranial hematoma is present.8 Traditionally,
the neurosurgical management involves evacuation of the hematoma with ligation of the parent
artery. The presence of surrounding clot also
makes aneurysm identification particularly difficult.
Surgery in the acute setting is technically difficult
because of the friable nature of the necrotic
tissue.11 Cardiac operations should be performed
only when neurologic status has stabilized and
CT scan reveals resolution of cerebral edema and
no ongoing cerebral hemorrhage.7 The approach
to the patient with unruptured intracranial infective aneurysms is controversial. Currently, there
are no data that precisely identify patients at risk
for imminent rupture, and decisions concerning
medical versus surgical therapy must be
individualized.9 When the location of the aneurysm is at a site where a new neurologic deficit
is likely to be introduced by neurosurgery, a
surgical approach must be carefully weighed.8 A
large proportion of unruptured proximal intracranial infective aneurysms, and aneurysms of the
cavernous sinus may resolve under appropriate
antimicrobial therapy, leading some authors to
recommend carefully clinical follow up and repeat
imaging scans and angiography within 7 to 14 days
for unruptured intracranial infective aneurysms.9
For aneurysms that remain unchanged or increase
in size on antibiotic therapy for 4-6 weeks,
surgical or transcatheter intervention is required
and may be individualized to the particular case.11
Although progressive heart failure and
systemic embolism are well-established indica323
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Sir-Chen Lin et al.
10. Hart RG, Kagan-Hallet K, Joerns SE. Mechanisms
of intracranial hemorrhage in infective endocarditis.
Stroke 1987;18:1048-1056.
11. Misser SK, Lalloo S, Ponnusamy S. Intracranial
mycotic aneurysm due to infective endocarditis—
successful NBCA glue embolisation. S Afr Med J
2005;95:397-9, 403-404.
12. Salgado AV, Furlan AJ, Keys TF. Mycotic aneurysm,
subarachnoid hemorrhage, and indications for cerebral angiography in infective endocarditis. Stroke
1987;18:1057-1060.
13. Corr P, Wright M, Handler LC. Endocarditis-related
cerebral aneurysms: radiologic changes with treatment.
AJNR Am J Neuroradiol 1995;16:745-748.
14. Masuda J, Yutani C, Waki R, Ogata J, Kuriyama Y,
Yamaguchi T. Histopathological analysis of the
mechanisms of intracranial hemorrhage complicating
infective endocarditis. Stroke 1992;23:843-850.
15. Kannoth S, Iyer R, Thomas SV, Furtado SV, Rajesh
BJ, Kesavadas C, Radhakrishnan VV, Sarma PS.
Intracranial infectious aneurysm: Presentation, management and outcome. J Neurol Sci 2007;256:3-9.
16. Sarica FB, Erdogan B, Tufan K, Cekinmez M, Kizilkilic
O, Sen O, Altinors MN. Endovascular treatment of
primary infectious aneurysm in childhood: a case
report. Turk Neurosurg 2008;18:47-51.
17. Yamada M, Miyasaka Y, Takagi H, Yada K. Cerebral
bacterial aneurysm and indications for cerebral
angiography in infective endocarditis. Neurol Med
Chir (Tokyo) 1994;34:697-699.
18. Utoh J, Miyauchi Y, Goto H, Obayashi H, Hirata
T. Endovascular approach for an intracranial mycotic
aneurysm associated with infective endocarditis. J
Thorac Cardiovasc Surg 1995;110:557-559.
19. Kong KH, Chan KF. Ruptured intracranial mycotic
aneurysm: a rare cause of intracranial hemorrhage.
Arch Phys Med Rehabil 1995;76:287-289.
20. Micheli F, Schteinschnaider A, Plaghos LL, Melero
M, Mattar D, Parera IC. Bacterial cavernous sinus
aneurysm treated by detachable balloon technique.
Stroke 1989;20:1751-1754.
21. Fiehler J, Byrne JV. Factors affecting outcome after
endovascular treatment of intracranial aneurysms.
Curr Opin Neurol 2009;22:103-108.
22. Chapot R, Houdart E, Saint-Maurice JP, Aymard A,
Mounayer C, Lot G, Merland JJ. Endovascular treatment of cerebral mycotic aneurysms. Radiology 2002;
222:389-396.
23. van der Schaaf I, Algra A, Wermer M, et al. Endovascular
coiling versus neurosurgical clipping for patients with
aneurysmal subarachnoid haemorrhage. Cochrane
Database Syst Rev 2005:CD003085.
intervention recovery is less complicated and
usually quicker. 11 A recent systematic review
identified three randomized trials comparing
clipping and coiling of intracranial aneurysms.
After 1 year of follow-up, the relative risk of
poor outcome for coiling vs. clipping was 0.76.23
Urgent cerebral angiography and an endovascular
approach to intracranial infective aneurysms,
especially for solitary and peripheral lesions, is
an acceptable option for some patients with active
endocarditis and severely damaged hearts. 18
Moreover, endovascular treatment should also be
preferred in patients who use anticoagulant drugs
due to heart valve replacement.16
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