Neurol Med Chir (Tokyo) 45, 249¿252, 2005

Postoperative Rupture of an Untreated Aneurysm on the
3rd Day After Subarachnoid Hemorrhage Surgery
—Case Report—
Yuji HASHIMOTO, Yoshifumi HORITA, Toshio IMAIZUMI, and Jun NIWA
Department of Neurosurgery, Hakodate Municipal Hospital, Hakodate, Hokkaido

Abstract
A 58-year-old male presented with severe consciousness disturbance and left hemiparesis. Computed
tomography (CT) revealed subarachnoid hemorrhage (SAH) and acute subdural hematoma caused by a
ruptured right middle cerebral artery aneurysm. The aneurysm was clipped and the hematoma was
evacuated. The patient had almost recovered without new neurological deficits on the next day. Arterial
systolic blood pressure was postoperatively controlled within 120 to 150 mmHg. Continuous ventricular
and cisternal drainage from the level 10 cm above the external auditory meatus was performed to drain
bloody cerebrospinal fluid and prevent vasospasm. Three days after surgery, the patient suddenly
lapsed into a coma. CT demonstrated diffuse SAH and bilateral intraventricular hemorrhage caused by
rupture of an anterior communicating artery aneurysm. Neck clipping was performed immediately.
Unfortunately, the patient died of primary damage due to SAH 3 days after the second surgery. In this
case, cisternal drainage was probably important in the aneurysm rupture because of decreased
intracranial pressure and change in the perianeurysm environment. Postoperative management of
patients with residual untreated aneurysms must consider the possibility that cisternal drainage may
result in higher transmural pressure, leading to rupture of the untreated aneurysms.
Key words: multiple aneurysms, unruptured aneurysm,
subarachnoid hemorrhage, cisternal drainage

Introduction

anterior communicating artery (ACoA) aneurysm
ruptured 3 days after surgery, presumably caused by
the postoperative management.

Multiple aneurysms are found in approximately
18–34% of intracranial aneurysm patients.3,7,8)
All unruptured aneurysms may be impossible to
treat during initial surgery in patients with
subarachnoid hemorrhage (SAH) because the unruptured aneurysms may be contralateral to the operated side or distant from the ruptured aneurysm, or
the patient may present with severe symptoms prior
to surgery or be elderly.1) The annual incidence of
hemorrhage from previously unruptured aneurysms
ranges from 0.5% to 2.3% in Japan.5,12,15) Patients
with unruptured aneurysms who have a prior
history of SAH and multiple aneurysms are at higher
risk of rupture,2,15) but such untreated aneurysms
rarely cause clinical problems in the postoperative
period.
We treated a patient for SAH but an undetected
Received
2004

March 31, 2004;

Accepted

ruptured aneurysm,

Case Report
A 58-year-old man, in good health except for being a
heavy smoker, lost consciousness at work for a few
minutes and was transferred to our hospital after
SAH was identified at a local hospital. On admission, he was in a deep coma with left hemiparesis.
The right pupil was dilated more than the left. His
eyes reacted sluggishly to light.
Computed tomography (CT) showed diffuse SAH
predominantly in the right sylvian cistern and
subdural hematoma (SDH) with mass effect that had
caused midline shift (Fig. 1). Digital subtraction
angiography (DSA) revealed a right middle cerebral
artery (MCA) aneurysm (Fig. 2), which was responsible for both SAH and SDH. DSA was concluded
after signs of cerebral herniation appeared, and
the patient was rushed to emergency surgery. He

November 22,

249

250

Y. Hashimoto et al.

"

Fig. 1

Fig. 3

Fig. 2

Right carotid angiogram on admission, left
oblique view, showing a middle cerebral
artery aneurysm (arrow).

underwent a right fronto-temporo-parietal large
craniotomy and evacuation of the SDH, followed by
clipping of the aneurysm through the right pterional
approach. Drainage of cerebrospinal fluid (CSF)
via a ventricular catheter during surgery relieved
the pressure on the brain. Neck clipping of the
aneurysm was achieved without complications. We
confirmed that the MCA aneurysm had ruptured.
A cisternal catheter was placed in the prepontine
cistern to drain the bloody CSF after surgery.
The patient recovered consciousness, and the left
hemiparesis disappeared on the 1st day after surgery
(day 1). The bloody CSF drained spontaneously from
drains placed 10 cm above the external auditory
canal. Additionally, the patient was treated with
intravenous administration of low molecular weight
dextran to maintain colloidal pressure and fasudil
hydrochloride (90 mg/day). We did not administer
agents to decrease intracranial pressure (ICP). The
ventricular catheter was removed on day 1, but the

Computed tomography scans
on admission showing diffuse
subarachnoid hemorrhage predominantly in the right sylvian fissure and acute subdural
hematoma with midline shift.

Computed tomography scans 3 days after
surgery showing thick subarachnoid hemorrhage in the interhemispheric fissure and
remarkably packed intraventricular hemorrhage.

cisternal drainage was continued. The volumes of
CSF collected were: day 0, 50 ml from the ventricular side; day 1, 170 ml from the ventricular and
200 ml from the cisternal side; day 2, 210 ml from
the cisternal side; day 3, 70 ml from the cisternal
side until the subsequent emergency. Systolic and
diastolic blood pressure averaged 150/80 mmHg.
The patient's clinical course was uneventful until
day 3 when he suddenly lapsed into a deep coma. CT
revealed thick diffuse SAH, especially in the
interhemispheric fissure, and hematoma castings in
the bilateral lateral ventricles (Fig. 3). The SAH
pattern did not match the initial imaging of the MCA
aneurysm. Left carotid angiography detected an
ACoA aneurysm for the first time (Fig. 4). The ACoA
aneurysm was clipped through the same right
pterional approach. However, postoperative CT
showed that a low density area had extended across
the whole brain parenchyma. The patient died 3
days after the second operation (day 6).

Neurol Med Chir (Tokyo) 45, May, 2005

Postoperative Rupture of Untreated Aneurysm

Fig. 4

Left carotid angiogram 3 days after surgery,
anteroposterior view, showing an anterior
communicating artery aneurysm (arrow)
projecting posteriorly.

Discussion
The risk factors for aneurysmal SAH related to
hypertension, smoking, and drinking are relatively
long-term factors which are also associated with the
formation of aneurysms.2) Physical examinations
and stress are immediate or short-term risk factors.10) These risk factors were mainly identified
statistically, but essentially suggest the importance
of increased blood pressure in aneurysm rupture.
Circadian variations in aneurysm ruptures actually
show a close correlation with the circadian fluctuations in the plasma concentrations of noradrenaline
and blood pressure.10,13) Physical activity and
Valsalva's maneuver can also easily affect blood
pressure.10)
Morphological factors may also be significant in
aneurysm rupture, such as aneurysm size, bleb
formation, wall thickness, and large dome/neck
ratio.2,9,14) Aneurysm rupture, especially in
aneurysms with morphological weakness, is thought
to be promoted by increased intraaneurysm pressure across the aneurysm wall due to an increase in
blood pressure or a decrease in ICP. Intraaneurysm
pressure sometimes resembles systemic blood pressure (SBP).10) These findings suggest that a rise in
arterial pressure may result in aneurysm rupture
due to increased hemodynamic stress. In our institution, SBP is observed not to be influenced until
about 180 mmHg by reduced cerebral blood flow because of vasospasm, even though an unruptured
aneurysm remains.

Neurol Med Chir (Tokyo) 45, May, 2005

251

Hypertensive hypervolemic therapy was given to
40 patients with a total of 73 untreated aneurysms
during a mean of 7.25 days who had suffered
vasospasm after SAH.1) Despite aggressive induction
of hypertension resulting in moderate SBP (180–200
mmHg) in 12 patients and severe SBP (À200 mmHg)
in nine patients, no bleeding occurred from the
unruptured aneurysms, although only 6.8% were
over 10 mm. In another study, 31 patients with 34
unruptured aneurysms, of which 29.4% were over
10 mm, received similar successful hypertensive
treatment.11) Therefore, short-term postoperative
hypertension is safe, even at the risk of adding
hemodynamic stress to the aneurysm. However, one
patient suffered fatal rupture of a giant carotid
aneurysm while undergoing hypertensive therapy,
although the details were not mentioned.4) In our
patient, SBP was maintained within 120–150
mmHg. Therefore, we considered other factors
except for hypertension as the cause of the
aneurysm rupture. But, we did not continuously
monitor SBP, so we do not know whether sudden
SBP changes actually occurred.
Intravenous administration of mannitol or
glycerol, ventricular drainage to control ICP, and
cisternal or lumbar drainage for evacuation of
bloody CSF to prevent vasospasm all reduce the ICP
and may lead to relatively increased transmural
pressure of the aneurysm. Ventricular drainage is
closely associated with an increased incidence of
aneurysm rebleeding, particularly in the presence of
hydrocephalus.6) This study suggests that decreases
in ICP caused by excessive drainage are associated
with proportional increases in the risk of aneurysm
rupture. Over 72% of ruptured aneurysms were in
contact with perianeurysm structures such as the
brain, dura, bone, and cranial nerves.9) These
aneurysm environment, particularly unbalanced
contact, is an additional important determinant in
the risk of aneurysm ruptures.
At our hospital, surgical procedures for SAH
include the placement of a ventricular drainage tube
to relieve pressure on the brain, even if the patient
does not present with acute hydrocephalus. A cisternal drainage tube is also placed in the carotid or
prepontine cistern to drain bloody CSF after surgery. Both drainage tubes are opened 10 cm above
the external auditory canal and allowed to drain
spontaneously. The ventricular drainage catheter is
removed as soon as it is no longer necessary for ICP
control, usually the day after the operation, and
cisternal drainage is continued for about 7 days,
based on reduction of SAH on CT or improvement
in the CSF from bloody to xanthochromic.
In the present case, an excessive amount of CSF,

Y. Hashimoto et al.

252

about 370 ml, was drained only on day 1 from both
ventricular and cisternal catheters; subsequent
drainage was about 10 ml per hour. Whether the ICP
of 10 cmH2O and the height of the cisternal drainage
level contributed to the aneurysm rupture is not
definitively known. Acute physical events such as
postural changes and Valsalva's maneuvers are
associated with reductions of ICP.10) A significant
fall in ICP due to excessive drainage of CSF can
occur particularly during drainage setting. Since
rupture of such an aneurysm is unusual, we
speculate that the rupture of the aneurysm was
associated with a decrease in ICP and/or a change in
the perianeurysm environment induced by CSF
drainage. If this hypothesis is accurate, prophylactic
management of vasospasm with evacuation of CSF
may directly affect the transmural pressure in the
aneurysm.
We did not recognize the unruptured aneurysm in
our patient before surgery because angiography
could not be completed. The possibility of unruptured aneurysms must be investigated as soon as
possible after surgery. If preoperative magnetic
resonance angiography or three-dimensional CT angiography had been performed, the ACoA aneurysm
could have been clipped at the same procedure. Unruptured aneurysm at risk is difficult to predict.
Therefore, postoperative management should consider the remaining aneurysms. Based on our experience, medical personnel should remain alert for
sudden changes in the rate of CSF drainage and
avoid the combination of hypertension and extensive drainage, especially in the presence of large or
irregular-shaped aneurysms at high risk of rupture.

5)

6)

7)

8)

9)

10)

11)

12)

13)

14)

References
1)

Hoh BL, Carter BS, Ogilvy CS: Risk of hemorrhage
from unsecured, unruptured aneurysms during and
after hypertensive hypervolemic therapy. Neurosurgery 50: 1207–1212, 2002
2) Juvela S, Porras M, Poussa K: Natural history of
intracranial aneurysms: probability of and risk
factors for aneurysm rupture. J Neurosurg 93:
379–387, 2000
3) Kaminogo M, Yonekura M, Shibata S: Incidence and
outcome of multiple intracranial aneurysms in
defined population. Stroke 34: 16–21, 2003
4) Kassell NF, Peerless SJ, Durward QJ, Beck DW,
Drake CG, Adams HP: Treatment of ischemic deficits

15)

from vasospasm with intravascular volume expansion and induced arterial hypertension. Neurosurgery 11: 337–343, 1982
Matsumoto K, Aragi K, Abekura M, Nakajima Y,
Yoshimine T: Investigation of the surgically treated
and untreated unruptured cerebral aneurysms of the
anterior circulation. Surg Neurol 60: 516–523, 2003
Pare L, Delfino R, Leblanc R: The relationship of
ventricular drainage to aneurysmal rebleeding. J
Neurosurg 76: 422–427, 1992
Rinne J, Hernesniemi J, Niskanen M, Vapalahti M:
Management outcome for multiple intracranial
aneurysms. Neurosurgery 36: 31–37, 1995
Rinne J, Hernesniemi J, Puranen M, Saari T: Multiple
intracranial aneurysms in a defined population:
prospective angiographic and clinical study. Neurosurgery 35: 803–808, 1994
San Millan Ruiz D, Tokunaga K, Dehdashti AR,
Sugiu K, Delavelle J, Rufenacht DA: Is the rupture
of cerebral berry aneurysms influenced by the
perianeurysmal environment? Acta Neurochir Suppl
82: 31–34, 2002
Schievink WI, Karemaker JM, Hageman LM, van der
Werf DJM: Circumstances surrounding aneurysmal
subarachnoid hemorrhage. Surg Neurol 32: 266–272,
1989
Swift DM, Solomon RA: Unruptured aneurysms and
postoperative volume expansion. J Neurosurg 77:
908–910, 1992
UCAS Japan Study Group: [Internal report of the
unruptured cerebral aneurysm study in Japan III]. No
Shinkei Geka Journal 13: 163–169, 2004 (Jpn, with Eng
abstract)
Vermeer SE, Rinkel GJE, Algra A: Circadian fluctuations in onset of subarachnoid hemorrhage: new data
on aneurysmal and perimesencephalic hemorrhage
and a systematic review. Stroke 28: 805–808, 1997
Weir B, Amidei C, Kongable G, Findlay JM, Kassell
NF, Kelly J, Dai L, Karrison TG: The aspect ratio
(dome/neck) of ruptured and unruptured aneurysms.
J Neurosurg 99: 447–451, 2003
Yasui N, Suzuki A, Nisimura H, Suzuki K, Abe T:
Long-term follow-up study of unruptured intracranial aneurysms. Neurosurgery 40: 1155–1160, 1997

Address reprint requests to: Y. Hashimoto, M.D.,
Department of Neurosurgery, Hakodate Municipal
Hospital, 1–10–1 Minato–cho, Hakodate, Hokkaido
041–8680, Japan.
e-mail: yu-hashimoto＠hospital.hakodate.hokkaido.jp

Neurol Med Chir (Tokyo) 45, May, 2005