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AANS 2007
Abstract: 2007 Apr 18
Dynamic intraspinous Spacer Technology (DIAM) for
Posterior Dynamic Stabilization: clinical and radiographic
mean 29 month follow-up
Author(s):
Keun-Young A. Kim, MD (Los Angeles, CA)
Matthew McDonald, MD (Adelaide, Australia)
Justin HT Pik, MD (Canberra, Australia)
Alex Taghva, MD
Michael Y. Wang, MD (Los Angeles, CA)
Introduction: We compared outcomes of patients post-microdiscectomy
or laminectomy lumbar surgery with dynamic intraspinous spacer
technology (DIAM) versus patients who underwent lumbar surgery
alone.
Methods: Seventy-four patients underwent simple lumbar surgery
(laminectomy and/or microdiscectomy) in a 60-month period.
Of these, 35 patients underwent concomitant surgical placement
of DIAM interspinous process spacer (a total of 42 DIAMs).
Postoperatively, magnetic resonance imaging, upright radiographic
imaging, pain scores, and clinical assessment were followed
to a mean of 29 months (range 17-60 months). Patients who
underwent no interspinous process spacer (Group C) were compared
with patients who underwent placement of DIAM (Group D).
Results: In Group D, no statistically significant differences
were noted in anterior or posterior disc height when comparing
pre- to postoperative patients. When compared with Group C,
a relative kyphosis of 3 degrees was noted in Group D postoperative
images (Group C: 2.68±0.54 degrees; Group D: -0.51±0.1
degrees). No statistically significant differences in pain
Visual Analogue Scale (VAS) or MacNab outcomes were noted
at a mean of 29 months follow-up between Groups C and D. Complications
in Group D included three intraoperative spinous process fractures,
one infection, and one case of markedly increased disc degeneration
and facet disease at 2-year follow-up.
Conclusions: Following simple lumbar surgery, placement of
a DIAM interspinous process spacer does not alter disc height
and sagittal alignment was minimally altered at a mean of
29 months follow-up. No difference in VAS or MacNab outcome
was noted between DIAM and non-DIAM groups, particularly in
the use of DIAM to alleviate low back pain.
Keywords:
lumbar surgery
posterior dynamic stabilization
DIAM
microdiskectomy
Abstract: 2007 Apr 15
A Lower Admission Glasgow Coma Scale (GCS) Score Corresponds
to an Increased Likelihood of Mashall Classification Progression
Author(s):
Jennifer Orning, BS
Alen Nourian, BS
Bill Zhou, MD
Chi S. Zee, MD
Bryan C. Oh, MD
Steven L. Giannotta, MD (Los Angeles, CA)
Introduction: Traumatic subarachnoid hemorrhage (tSAH) is
common in patients with head injury. The Marshall classification
is becoming used more frequently to grade the severity of
tSAH. However, little data exist regarding specific factors
that contribute to the development of a higher Marshall score.
This study was designed to identify factors that put tSAH
patients at risk for developing a higher Marshall score.
Methods: From June to August 2006, 30 patients (22 males
(age 46.4 ± 18.9 years) and eight females (age 45.8
± 26.1 years)) were admitted to LAC+USC Medical Center
with an admission diagnosis of tSAH, given an initial Marshall
score, and followed prospectively. Other data gathered were
initial Glasgow Coma Scale (GCS) score, coagulation status,
blood pressure, and toxicology screen. All patients received
follow-up head computed tomography (CT) scans for surveillance
12-24 hours after the initial scan or for change in examination.
All Marshall scores were assigned by the same neuroradiology
staff.
Results: Patients were grouped into one of three categories:
1) improved (or lower) Marshall score; 2) stable score; or
3) worse (or higher) score. The patients who developed a higher
Marshall score had a lower initial GCS score (7.1±3.8)
compared with patients who had stable a Marshall score (GCS
11.9±4.5). This difference, however, was not statistically
significant (P less than 0.06). The patients who developed
a higher Marshall score had a significantly lower (P less
than 0.01) initial GCS (7.1±3.8) compared with patients
who had a lower Marshall score on follow-up imaging (12.0±2.5).
Conclusions: This study suggests that tSAH patients who develop
a higher Marshall score tend to present with a significantly
lower GCS score.
Keywords:
Traumatic Subarachnoid Hemorrhage
Marshall Classification
Traumatic Brain Injury
Head Trauma
Abstract: 2007 Apr 15
Calvarial Growth Following Surgical Treatment of Craniosynostosis
Author(s):
Alex Khalessi, MD
Mark D. Krieger, MD
Ira Bowen, BA
J. Gordon McComb, MD (Los Angeles, CA)
Introduction: Calvarial growth may represent a viable outcome
measure for the surgical treatment of craniosynostosis.
Methods: From 2000 to 2005, 117 children were surgically
treated for craniosynostosis at a single institution. Head
circumference (HC) measurements were retrospectively reviewed
preoperatively, immediately postoperatively (1-2 weeks), and
at short-term follow-up (6 months to 1 year). Using population-based
HC growth curves, data points were assigned a percentile score.
Subjects were classified into three postoperative outcome
states: 1) patient HC remained stable on a percentile growth
curve, 2) patient HC moved to a lower percentile growth curve,
and 3) patient HC moved to a higher growth curve.
Results: Study population descriptive statistics were as
follows: mean age 9 months; gender breakdown: 26% female and
74% male; and follow-up from 3 to 56 months (mean 18 months).
Subsets included: isolated sagittal synostosis (ISS) (59%),
coronal synostosis (18%), metopic (5%), lambdoidal (5%), and
multiple suture synostosis (MSS) (13%). ISS and MSS populations
demonstrated divergent outcomes. Eighty-nine percent of MSS
patients moved to a higher HC percentile curve postoperatively,
and all experienced absolute HC increases. Fifty percent of
ISS patients moved to a lower HC percentile curve postoperatively,
the only synostosis subset to do so. The remaining ISS patients
were divided evenly among stable (27%) and increased (23%)
HC percentile groups.
Conclusions: Serial HC measurement may meaningfully quantify
the efficacy and degree of surgical correction for craniosynostosis.
In MSS, multi-dimensional suture release may relieve restrictions
on normal brain development and correspond with increased
calvarial growth. The scaphocephalic deformity of ISS, by
contrast, leads to a disproportionately increased HC relative
to cranial vault volume preoperatively. Sagittal suture release
restores a more anatomic, spherical cranial vault volume relationship
and continued normal growth. Decreased percentile HC growth,
as demonstrated by our study population, may therefore represent
a successful surgical result in ISS patients.
Keywords:
craniosynostosis
calvarial growth
surgical treatment
pediatrics
CNS 2006
Revision And Explantation Strategies Involving The
Charite Artificial Disc
Authors:
Scott P. Leary, MD; Todd Hopkins Lanman, MD; John J. Regan,
MD
Introduction: The purpose of this study is to characterize
the etiology and strategies utilized when a revision or explantation
procedure is necessary following a failure of lumbar total
disc replacement with the Charité intervertebral prosthesis.
Methods: A retrospective analysis of 17 consecutive cases
over a four-year period was performed. Each case involved
a primary revision or explantation procedure involving a Charité
intervertebral prosthesis.
Results: We analyzed 17 consecutive cases referred to the
senior author for revision surgery. 14 of 17 cases required
removal of the implant and conversion to a fusion. In three
cases, primary revision of the implant was performed. Early
revision was performed in 7 cases (7-14 days) all as a result
of implant displacement. 10 late revisions were performed
from 6 weeks to 2 years. Technical errors during initial implant
surgery were felt to be the cause of implant dislocation or
failure in 8 cases. In 4 cases the artificial disc procedure
was contraindicated due to end stage facet disease or spondylolisthesis.
In 5 cases, implant dislocation occurred as a result of a
fall or trauma.
Implant revision strategies were determined by the length
of time from the original surgery and the location of the
implant. All early revisions from 7 to 14 days were managed
using the original retroperitioneal incision. Late revisions
required a variety of approaches. Ureteral stenting was utilized
for the L4-5 approaches. Preoperative vascular studies were
performed in cases of late dislocation. There were no vascular,
ureteral or neurologic injuries and no blood transfusions
were required.
Conclusions: Factors that contribute to unsuccessful total
disc replacement are primarily performing the procedure in
contraindicated patients and technical errors of original
implantation. The most common technical errors are use of
an oversized implant or anterior positioning of the implant.
In our series, revision surgery was successful in all cases.
Format:
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Meeting:
CNS 2006 Annual Meeting Chicago
MR-Myelogram for Detection of Lumbar Facet Synovial
Fluid Abnormalities and Predicting Positive Response to Facet
Injection Authors:
Anthony K. Kim; Michael Y. Wang; Carlos Ledezma; Alex Tagva;
David Nicholas; Robert Wykoff
Introduction: We investigate the use of magnetic resonance
myelogram (MrM) and SPECT in selecting inflamed facets and
predicting a favorable response to lumbar facet injection.
Methods: Twenty-one consecutive patients (110 facets) with
severe axial back pain underwent lumbar MRI prior to facet
injection. Noninvasively, MrM was reconstructed from fine-cut
coronal T2W images. Facets were segregated using a previously
described grading system based on synovial architecture and
content. Patient outcome was evaluated with standard pain
scale questionnaire at 2 weeks.
Results: Of 110 facets, 29 facets demonstrated the following
findings: (a) bright T2W synovial signal (b) cartilaginous
abnormality forming a mottled synovial pattern (c) synovial
fluid out of proportion to that normally seen in the synovial
space. Sensitivity and specificity for MrM to independently
identify these facets were 0.83 and 1.0 (P = 0.0001). 89%
of patients with positive MrM reported significant relief
of pain post injection. During a 4-month period, 8 of 10 patients
with (+) MrM re-requested facet injections for pain relief.
Conclusions: MrM had a 92% positive predictive value and a
100% negative predictive value for detecting fluid surrounding
a subset of facets. These facets have bright T2WI signal,
cartilaginous mottled abnormalities and often have synovial
fluid out of proportion to standard. Such facets were noted
to be (+) SPECT in a previous study (0. 90 specificity, p
= 0.0001). Fluid accumulation and increased blood flow were
confirmed in a subset of facets via SPECT findings and MrM.
MrM may be a valuable adjunct in the detection of inflamed
facet joints.
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Meeting:
CNS 2006 Annual Meeting Chicago
Correction of Late Traumatic Kyphotic Spinal Deformities
Using Posteriorly Placed Intervertebral Distraction Cages
Authors:
Michael Y. Wang; Daniel H. Kim, MD; Anthony K. Kim Introduction:
We performed a study to assess the safety and stability of
deformity correction from a solely posterior approach with
placement of anterior cages and posterior segmental fixation
in one operation.
Methods: 23 patients who failed brace trial for at least 6
months were included in the series. All patients had progressive
neurologic deficit or evidence of deformity progression at
time of operation. All patients underwent a single operation
in the prone position. Transpedicular segmental fixation was
accompanied by anterior column reconstruction using either
expandable or stackable cages without nerve root sacrifice.
Stackable cages were used for high thoracic deformity. Deformity
Cobb angle and plain radiograph evaluation of fusion ensued
for mean follow-up 15 months.
Results: All patients achieved correction of deformity without
undue complications. Improved or maintained ASIA scores were
noted in all patients. Mean operation time was 316 min +/-
34.5 S.D, or, ~ 5 hours. Pre-op deformity mean Cobb angle
was 26 deg +/- 9.2 S.D. Postop mean angle was 12.1 deg +/-
4.5 SD with resultant mean deformity correction of 14.2 deg
+/- 6.8 SD. At mean 15 month follow-up, no patients demonstrated
loss of deformity correction. Plain radiographic evidence
suggestive of fusion was noted in all patients. Some degree
of neurological dysfunction was present due to spinal cord
compression in all but four patients. Of the 19 patients with
deficits, three were unchanged after surgery. The remainder
experienced improvements. Fifteen advanced one ASIA grade
and one improved two grades. No patients experienced neurological
deterioration.
Conclusions: Delayed kyphotic deformity correction of the
thoracolumbar spine is achieved via a posterior-only approach.
Posterior segmental fixation and anterior column reconstruction
was performed in one surgical setting without the need for
nerve root sacrifice when using stackable versus expandable
cages. At 15 months, post-surgical Cobb angles remained stable.
Improved fusion criteria and further follow-up will be required
to determine fusion and loss of correction rates over time.
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CNS 2006 Annual Meeting Chicago
Development of an accelerated ovine model for degenerative
lumbar facet joint arthrosis Authors:
Michael Y. Wang; Anthony K. Kim; Hassan A Serhan, PhD; H.B.
Seim; Simon Turner
Introduction: Facet degeneration is commonly observed in the
aging population. However, little is known about the natural
history, etiological factors, and clinical significance of
facet arthrosis. One barrier to investigation in this area
has been the paucity of animal models. Moore, et al. demonstrated
the induction of facet degeneration through annular rim lesioning
in a sheep model, but produced only mild histopathological
arthritic changes after greater than one year. The goal of
this study was to develop and refine a large animal model
of accelerated facet joint arthrosis through disruption of
the anterior vertebral column.
Methods: Sixteen skeletally mature Rambouillet Columbian ewes
were utilized in the experimental group. Sheep were maintained
in strict accordance with animal care guidelines in open range.
Surgical disruption of the anterior column was performed with
a large annulotomy via a retroperitoneal approach, leaving
the posterior spinal elements completely undisturbed. Three
adjacent disc levels were lesioned. Animals were sacrificed
at 3 (n=2), 6 (n=4), 9 (n=4), and 12 (n=6) months. Spiral
CT and MRI analysis of the bony and soft tissue structures
after animal sacrifice
Results: Radiographic findings of the posterior elements in
the experimental group were compared with animals that had
not undergone surgery. Those in the experimental group demonstrated
progressive radiographic evidence of posterior element degeneration.
This included enlargement of the bony articular process, osteophytic
lipping, and loss of the synovial space and fluid signal.
The posterior bony elements hypertrophied an average of 24%
on axial CT images.
Conclusions: This study demonstrates that disruptions in anterior
column integrity can lead to accelerated changes in the posterior
joint structures. The changes occur within twelve months and
radiographically resemble the changes seen in human degenerative
disease. This model may prove useful for studying the pathological
process of facet arthrosis and interventions to reduce these
changes.
Format:
Digital Poster
Meeting:
CNS 2006 Annual Meeting Chicago
Use of Invasive Continuous Cardiac Output Monitoring
in Management of Patients with Aneurysmal Subarachnoid Hemorrhage
Authors:
Bryan C. Oh, MD; Allan Christopher Heller, MD; James B. Elder,
MD; Michael Y. Wang, MD; Charles Y. Liu; Steven L. Giannotta,
MD
Introduction: The traditional Swan-Ganz catheter, a mainstay
of management in patients with aneurysmal subarachnoid hemorrhage,
uses a standard bolus thermodilution technique to measure
cardiac output. Recently, a continuous cardiac output (CCO)
Swan-Ganz catheter was developed to provide rapid and accurate
assessment of the response of critically ill patients to various
treatments. To our knowledge, nobody has assessed the use
of the CCO Swan-Ganz catheter in management of patients with
aneurysmal subarachnoid hemorrhage.
Methods: Between January 2004 and January 2006, 97 patients
were admitted to USC University Hospital with the diagnosis
of aneurysmal subarachnoid hemorrhage. We review our results
of invasive CCO monitoring in this patient population.
Results: CCO Swan-Ganz catheters were inserted into 43 (10
male, 33 female; ages 28-81, mean 60.7) of the 97 (25 male,
72 female) patients studied. In 38 of these patients, catheter
insertion was done for triple-H therapy guidance after transcranial
doppler and CT angiography results confirmed clinically suggested
vasospasm. In 2 cases, catheter placement was performed for
guidance of fluid management in patients with documented congestive
heart failure (CHF). In the remaining 3 cases, catheters were
placed for: 1)cardiac function monitoring in a patient with
critical aortic stenosis, 2)fluid management in a patient
who suffered a massive stroke after intraoperative rupture,
3)treatment guidance in a patient who suffered a cardiac arrest
prior to transfer. Of the 38 patients who received triple-H
therapy, 30 demonstrated neurological improvement. Both of
the CHF patients, the patient with aortic stenosis, and the
patient who suffered a cardiac arrest all showed improvement
in their cardiopulmonary status. The patient who suffered
a stroke died. Line sepsis occurred in 3 of the 43 cases.
There were no other complications of catheter placement.
Conclusions: Invasive CCO monitoring is a safe and effective
tool that can be used in the management of patients with aneurysmal
subarachnoid hemorrhage.
Format:
Digital Poster
Meeting:
CNS 2006 Annual Meeting Chicago
Outcomes and Complications from Triple-H Therapy Using
Invasive Continuous Cardiac Output Monitoring Authors:
Bryan C. Oh, MD; Allan Christopher Heller, MD; Daniel J. Hoh,
MD; Michael Y. Wang, MD; Charles Y. Liu; Steven L. Giannotta,
MD
Introduction: Triple-H therapy is an accepted treatment for
cerebral vasospasm. Traditionally, the standard Swan-Ganz
catheter that uses a bolus thermodilution technique using
cold saline has been used to guide triple-H therapy. Recently,
a Swan-Ganz catheter capable of measuring continuous cardiac
output (CCO) has been developed. However, nobody has used
invasive CCO monitoring to guide triple-H therapy.
Methods: We report our experience with the CCO Swan-Ganz catheter
in treatment of patients who developed vasospasm after aneurysmal
subarachnoid hemorrhage (SAH). We analyzed data from patients
admitted to our facility with the diagnosis of aneurysmal
SAH from January 2004 to January 2006. Triple-H therapy was
instituted in patients who demonstrated clinical evidence
of vasospasm that was confirmed by both transcranial doppler
and CT angiogram studies. Therapy goals were to keep the pulmonary
capillary wedge pressure (PCWP) between 12-16 mm Hg and the
cardiac index (CI) between 4-5 L/min/sq m.
Results: During this period, 97 patients (25 male, 72 female)
were admitted to USC University Hospital with aneurysmal SAH.
Of this group, 38 patients (9 male, 29 female; ages 28-81,
mean 59.8) developed vasospasm and were treated with triple-H
therapy. On average, triple-H therapy commenced 5.3 days after
the SAH occured and lasted for 7.7 days. Thirty of 38 patients
demonstrated improvement in neurologic function after triple-H
therapy. Of these 30 patients, 10 underwent cerebral angioplasty.
Of the 8 patients who did not improve after triple-H therapy,
4 underwent cerebral angioplasty. Final disposition of these
38 patients was as follows: 9 home, 13 acute inpatient rehabilitation,
13 skilled nursing facility, 3 died. Regarding complications
of triple-H therapy, there were 2 cases of myocardial infarction
and 2 cases of line sepsis. Additionally, 1 patient required
a durotomy for increased intracranial pressure.
Conclusions: Invasive CCO monitoring is an effective and safe
guide of triple-H therapy for patients with cerebral vasospasm.
Format:
Digital Poster
Meeting:
CNS 2006 Annual Meeting Chicago
Differential Expression of Angiogenic Markers in Arteriovenous
Malformation-Brain Derived Endothelial Cells (AVM-BEC)
Authors:
Mark N. Jabbour, MD; Christian G. Samuelson, BS; James B.
Elder, MD; Charles Y. Liu; Florence M. Hofman, PHD; Steven
L. Giannotta, MD
Introduction: Brain arteriovenous malformations (BAVMs) have
been reported to be highly angiogenic, proinflamatory lesions,
often prone to hemorrhage and continuous expansion over time.
In order to understand the mechanisms of this pathology, we
have successfully characterized the angiogenic properties
of AVM-BEC and identified significant differences between
these cells and control brain endothelial cells (BEC).
Methods: Purified AVM-BEC were grown on cover glass slides
for 2 days, and stained with the following angiogenic markers:
endothelin-1(ET-1), VEGF-A, VEGF-R1, VEGF-R2, VE-Cadherin
and integrin avb3. Immunostaining was evaluated using HSCORE,
which quantifies intensity and percent distribution of staining
(percent intensity unit= piu). Control BEC were isolated from
epilepsy surgical specimens. Data were analyzed by paired
Student’s t test and reported as means +/- standard
deviation.
Results: Our results demonstrate that AVM-BEC in comparison
to BEC expressed significantly higher levels of ET-1 (HSCORE=
422.9 +/- 29.6piu versus 285.7 +/- 35.5 piu; P = 0.02) and
VEGF-A (HSCORE= 444.5 +/- 51.7 piu versus 301.8 +/- 30.6 piu;
P = 0.02). There was no difference in VEGF-R1 (flt-1) expression
between AVM-BEC and control BEC (HSCORE= 379.2 +/- 56.1piu
versus 310.3 +/- 12.8 piu; P = 0.16), however VEGF-R2 (flk-1)
was significantly decreased (HSCORE= 280.7 +/- 7.5 piu versus
373.3 +/- 15.6 piu; P < 0.01). The expression of the tight
junction protein, VE-Cadherin was decreased (HSCORE= 244.7
+/- 31.0 piu versus 406.4 +/- 15.5 piu; P < 0.01), while
integrin (avb3) was strongly expressed in AVM-BEC compared
to control BEC (HSCORE= 391.3 +/- 38.4 piu versus 192.7 +/-
42.3 piu; P < 0.01).
Conclusions: AVM-BECs demonstrate upregulation of a variety
of pro-angiogeneic growth factors and receptors, as well as
different structural molecules compared to control BEC.
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CNS 2006 Annual Meeting Chicago
Functional Abnormalities in Endothelial Cells Derived
from Arteriovenous Malformations Authors
Mark N. Jabbour, MD; Christian G. Samuelson, BS; James B.
Elder, MD; Charles Y. Liu; Steven L. Giannotta, MD; Florence
M. Hofman, PHD
Introduction: Arteriovenous malformation in the brain exhibit
significant vascular abnormalities. To understand the mechanisms
involved in this aberrant vasculature, we investigated arteriovenous
malformation brain-derived endothelial cells (AVM-BEC) and
showed that these cells express different morphologic and
phenotypic characteristics compared to normal brain-derived
endothelial cells (BEC). Based on these studies, the functional
potential of AVM-BEC in tubule formation and cell migration,
was analyzed for specific angiogenic properties, and demonstrated
to be significantly different from BEC.
Methods: Isolated, purified, and characterized AVM-BEC were
used in the in vitro angiogenesis tubule formation, using
the standard 3-dimensional matrix. Cells were labelled with
a green fluorescent dye (CFDA-SE). The average cell length/tubule
is reported. AVM-BEC were tested for migration, using the
modified Boydon chamber technique. Control BEC were isolated
from epilepsy surgical specimens. Data were analyzed using
the paired student’s t test for tubule formation and
one-way ANOVA test for migration assay.
Results: The results show that AVM-BEC migrate faster than
BEC [F(3,36) = 64; P < 0.01]. Treatment with angiogenic
factor IL-8 (1ng/ml) caused faster migration of BEC while
AVM-BEC migrated less [F(3,36) = 64; P < 0.01]. In the
tubule formation assay, AVM-BEC failed to form normal tubule-like
structures (43.3 ± 9.4um versus 65.9 ± 10.6um;
P < 0.01) as observed in BEC cultures. Treatment with VEGF
(10ng/ml) or TGF-B (10ng/ml) enhanced tubule formation in
BEC (97.1 ± 31.1um; P = 0.02, and 81.5 ± 22.0um;
P = 0.02, respectively), however in AVM-BEC no tubules were
observed.
Conclusions: These results demonstrate that AVM-BEC have aberrant
angiogenic functions compared to BEC. AVM-BEC cannot form
proper tubules; and these cells appear to migrate at a faster
rate than BEC. AVM-BEC have distinct functional properties,
that are different from BEC.
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Meeting:
CNS 2006 Annual Meeting Chicago
Characterization of Arteriovenous Malformation-Brain
Derived Endothelial Cells (AVM-BEC) Authors:
Christian G. Samuelson, BS; Mark N. Jabbour, MD; James B.
Elder, MD; Charles Y. Liu; Florence M. Hofman, PHD; Steven
L. Giannotta, MD
Introduction: Brain Arteriovenous malformations (BAVMs) represent
a unique cerebrovascular pathology whereby arteries are directly
connected to veins without evidence of capillary plexus formation.
The goal of this study is to identify differences between
endothelial cells derived from BAVMs compared to normal brain
endothelial cells (BEC).
Methods: BAVM endothelial cells, were obtained from surgical
specimens of AVM lesions. BEC controls were obtained from
epilepsy surgical specimens. This population was isolated
and characterized using flow cytommetry (F.A.C.S), and immunohistochemical
staining procedures. Stained slides were graded using the
HSCORE method, which quantifies intensity and percent distribution
of staining (percent intensity unit= piu). Cell proliferation
was assessed using Ki-67 staining and calculating the percent
of positive cells. Data were analyzed by paired Student’s
t test and reported as means +/- standard deviation.
Results: We characterized both AVM-BEC and control BEC by
staining for endothelial specific markers CD31 and FVIII,
and sorting for acetylated LDL-receptor, resulting in greater
than 95% purity. AVM-BEC expressed a higher Ki-67 proliferative
index than BEC (62 +/- 13% versus 15 +/- 3%; P < 0.01),
which represented a 4-fold increase in the number of dividing
cells. AVM-BEC have an altered cell morphology in comparison
to BEC, and express significantly decreased levels of CD105
(Endoglin) (HSCORE = 200 +/- 1piu versus 360 +/- 53piu; P
< 0.01) and eNOS (endothelial nitric oxide synthase) (HSCORE
= 109 +/- 3piu versus 461.7 +/- 15.3piu; P = 0.01).
Conclusions: We have successfully isolated and characterized
a pure population of AVM-BEC. Furthermore, we showed that
these AVM-BEC have different phenotypic characteristics compared
to normal brain endothelial cells.
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Meeting:
CNS 2006 Annual Meeting Chicago
Post-operative Continuous Paravertebral Anesthetic Infusion
for Pain Control in Lumbar Spinal Fusion Surgery: A Case-Control
Study Authors:
James B. Elder, MD; Michael Y. Wang
Introduction: Patients who undergo lumbar spine procedures
frequently experience significant, debilitating pain related
to their surgery. This pain may delay postoperative mobilization,
increase length of hospitalization and require prolonged use
of high doses of narcotics. Use of a local anesthetic continuous-infusion
pump after surgery may lead to improvement in these outcome
variables.
Methods: After posterior lumbar spine fusion procedures, 26
consecutive patients received continuous infusion of 0.5%
marcaine into the sub-fascial aspects of the wound via an
elastomeric pump. Data were collected prospectively by third
party assessment using standard nursing protocols. This included
pain scores and opiate use over the first 5 post-operative
days, length of hospitalization, and complications. Retrospective
analysis compared each study patient to a case-control patient.
Variables such as age, gender, and surgical procedure were
similar between matched cases.
Results: Patients receiving continuous local anesthetic infusion
used 21.5% less narcotics on post-operative day 1, 37.4% less
on day 2, and 26% less on day 3 compared to control patients.
Differences in opiate usage were negligible on post-operative
day 4 (0.04% greater) and 5 (0.07% greater). A lower average
pain score was observed among the study patients on each post-operative
day: 23.9% less pain on day 1, 19.0% on day 2, 17.8% on day
3, 16.8% on day 4, and 40.4% on day 5. No differences were
observed in length of hospitalization or complications.
Conclusions: Patients with a local anesthetic continuous-infusion
device used less narcotics than case-control patients over
the first 3 postoperative days, and reported lower pain scores
during the first 5 postoperative days. These results suggest
that continuous infusion of local anesthetic into the paravertebral
tissue during the immediate postoperative period is a safe
and effective technique that achieves lower pain scores and
narcotic use. Further data may reveal additional benefits
such as decreased times to mobility and functional independence.
Format:
Open Paper
Meeting:
CNS 2006 Annual Meeting Chicago
Review of Fenestrated Aneurysm Clip Ligation for Anterior
Communicating Artery Aneurysms Authors:
Gabriel Zada, MD; Eisha Christian, BS; Steven L. Giannotta,
MD
Introduction: Since their conception in 1969, fenestrated
aneurysm clips have become useful tools in the surgical clip
ligation of a wide spectrum of aneurysms. The use of the fenestrated
aneurysm clip for aneurysms of the Anterior Communicating
Artery was reviewed in order to identify particular situations
that surgeons may be more likely to utilize fenstrated clips
for securing AComm aneurysms.
Methods: A retrospective patient record review was conducted
to identify patients undergoing surgical clip ligation of
an AComm Artery aneurysm with the use of a fenestrated aneurysm
clip between 1990-2005. Data was reviewed and subsequenlty
analyzed.
Results: Two hundred four patients that underwent surgical
clipping of an AComm Artery aneurysm were identified. Of these
patients, fenestrated aneurysm clips were used in 17 cases
(8%). The majority of aneurysms pointed superiorly or posteriorly,
and the mean aneurysm size was 9 mm. The following structures
were included in the clip aperture: Ipsilateral A2 artery,
11 patients (66%); Ipsilateral A1 artery, 4 patients (23%);
Recurrent artery of Heubner, 1 patient (6%), Frontopolar artery,
1 patient (6%). Aneurysms approached from the left side more
frequently required fenestrated clips than did right-sided
aneurysms (76 versus 24%, p=0.0053). All 17 patients demonstrated
patency of the A2 vessels on postoperative angiography.
Conclusions: The fenestrated aneurysm clip has become an integral
tool in the surgical clipping of complex AComm Artery aneurysms.
As an ever growing number of these lesions are treated by
coil embolization, more complex aneurysms cases are being
referred for surgical clipping. For large or superiorly pointing
aneurysms, the use of a fenestrated clip may allow the surgeon
to limit tedious and potentially dangerous dissection of adherent
branch vessels, while maintaining the integrity of structures
placed in the fenestration.
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Meeting:
CNS 2006 Annual Meeting Chicago
Surgical Clip Ligation of Internal Carotid Artery Aneurysms
Occurring at the Origin of Fetal Variant Posterior Cerebral
Arteries Authors:
Gabriel Zada, MD; Julia Breault, BS; Steven L. Giannotta,
MD
Introduction: Fetal variant posterior cerebral arteries (Fetal
PCAs) have been reported to occur in approximately 21% of
the population. Internal Carotid Artery (ICA) aneurysms arising
from the origin of fetal variant posterior cerebral artery
aneurysms (Fetal PCAs) require special attention as obliteration
of a Fetal PCA is more likely to result in neurological deficits
with a wider distribution of cerebral ischemia.
Methods: A retrospective chart review was conducted for all
patients undergoing surgical clipping of a posterior communicating
artery (PComm) aneurysm at LAC-USC Medical Center over a fifteen
year period (1991-2005), in order to identify cases with aneurysms
originating from fetal variant PCAs. Data was retrospectively
reviewed and analyzed.
Results: Of the 189 patients that had PComm aneurysm treated
surgically over a fifteen period, 24 patients (13%) were identified
with aneurysms originating at the origin of fetal variant
PCAs. Two of these patients had bilateral fetal PCA variants.
Aneurysms were left sided in 12 cases and right sided in 12
cases. The mean aneurysm size was 6 mm. The mean ischemia
time with temporary clipping (12 cases) was 4.5 minutes. Intraoperative
rupture occurred in 6 cases (25%). Postoperative angiography
demonstrated occlusion of the fetal PCA in 1 case (4%), with
an ensuing occipital infarct yet no clinical sequelae.
Conclusions: It is important to identify the presence or absence
of fetal PCA variants on preoperative imaging studies. Aneurysms
occurring at the takeoff of fetal PCA vessels are frequently
encountered in a distribution expected based on previous studies.
Aneurysms originating from the ICA at the takeoff of a Fetal
variant PCA may pose a more substantial risk for infarction
and subsequent neurological deficit with surgical or endovascular
obliteration. The presence of a fetal variant PCA aneurysm
may lend support to opting for surgical clip ligation over
endovascular occlusion of these aneurysms.
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Meeting:
CNS 2006 Annual Meeting Chicago
Treatment of Cerebral Dural AVFs with Onyx® Liquid
Embolic System
Authors:
Azadeh Farin
Introduction: Onyx, a radiopaque nonadhesive liquid embolizate,
has had successful applications in peripheral, intracranial
and spinal AVMs; one wide-necked renal aneurysm; and peripheral
pseudoaneurysms. Onyx is composed of ethylene vinyl alcohol
copolymer, and solidifies upon blood contact forming a compressible
embolus. Here we demonstrate feasibility and efficacy of Onyx
embolization of dural AVFs.
Methods: During 2006, Onyx was used in two procedures to treat
two patients with dural AVFs. Case 1: A 53-year-old male presented
with syncope, pulsatile tinnitus, and seizures. Imaging revealed
a dural AVF at the right transverse-sigmoid sinus junction
supplied by the right occipital artery and drained by the
right superior petrosal sinus. Case 2: A 73-year-old male
with headache had a dural AVF in the right interhemispheric
fissure supplied by right middle meningeal and superficial
temporal arteries with veins draining to the sagittal sinus.
Results: Onyx embolization was successful in both cases. In
Case 1, the AVF was occluded entirely with preservation of
transverse sinus patency. In Case 2, flow was reduced 95-99%;
remaining feeders were too small to embolize. This patient
experienced embolizate reflux, limiting migration of Onyx
deeper into the lesion. Both patients remained at neurologic
baseline and experienced symptom/sign improvement without
adverse events including recurrent hemorrhage. Neither case
exhibited angiographic evidence of distal nontargeted embolization.
Conclusions: Preliminary data suggests Onyx is safe and effective
for embolization of dural AVFs. Onyx is advantageous over
conventional agents because its nonadhesive, low viscosity
nature facilitates deep, extensive penetration into the plethora
of small feeding vessels before it coagulates proximally,
making a one-injection cure possible. Other agents solidify
prior to penetrating the entire target, providing only proximal
embolization. While Onyx’ low viscosity may conversely
potentiate disastrous nontarget embolization and its long-term
efficacy requires further study, its unique properties make
it a potentially promising agent for cure of cerebral vascular
malformations.
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Meeting:
CNS 2006 Annual Meeting Chicago
Langerhans Cell Histiocytosis in the Pediatric Population
Authors:
Laurence Davidson, MD; Mark D. Krieger, MD; J. Gordon McComb,
MD; Ira Bowen, BA
Introduction: Langerhans cell histiocytosis (LCH) typically
presents to the neurosurgeon with the identification of a
lesion of the skull or vertebrae, or with diabetes insipidus.
LCH is a rare disease of unknown etiology, affecting primarily
infants and children. The disease course can be quite variable,
affecting one or multiple organ systems and ranging from benign
to fulminant. Eosinophilic granuloma, Hand-Schuller-Christian
disease and Letterer-Siwe disease are all forms of LCH. Disease
course following the identification of a lesion with neurosurgical
consequences is poorly quantified.
Methods: To determine disease course after identification
of a lesion of the neuroaxis we retrospectively reviewed 67
children with LCH treated by a pediatric neurosurgical department
over a 25 year period.
Results: This series included 72% boys and 28% girls, ranging
in age from 6 months to 13 years (average 5.6 years). Follow-up
ranged from 4 months to 25 years, with an average of 3.5 years.
88% had skull lesions, 8% had spine lesions and 4% had lesions
in the hypothalamic-pituitary axis. No patients died of their
disease. 80% of the patients had unifocal disease at presentation
of which 10% developed multifocal disease. 20% of the patients
were found to have multifocal disease at presentation, 60%
of which developed new lesions during the follow-up period.
Time to disease progression ranged from 2 months to 3 years.
Age less than 5 years at the time of initial presentation
was a risk factor for both multifocality and progression.
All patients with multifocality or progression had their disease
controlled by chemotherapy.
Conclusions: This large and unique series of patients with
LCH demonstrates the need for extent of disease evaluation
both at presentation and at follow-up. Young patients who
present with multifocal disease are much more likely to progress
and will require systemic therapy to control their disease.
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Meeting:
CNS 2006 Annual Meeting Chicago
AANS 2006
Abstract: 2006 Nov 29
Cavarial Growth Following Surgical Treatment of Craniosynostosis
Author(s):
Alex Khalessi,MD, Los Angeles, CA
Mark D. Krieger,MD, Childrens Hospital Los Angeles, Los Angeles,
CA
Ira Bowen,BA, Los Angeles, CA
J. Gordon McComb,MD, Los Angeles, CA
Introduction: Calvarial growth may represent a viable outcome
measure for the surgical treatment of craniosynostosis.
Methods:117 children were surgically treated for craniosynostosis
at a single institution from 2000 to 2005. Head circumference(HC)
measurements were retrospectively reviewed pre-operatively,
immediately post-operatively(1-2weeks), and at short-term
follow-up (6months to 1year). Using population-based HC growth
curves, data points were assigned a percentile score. Subjects
were classified into three post-operative outcome states:
(1)patient HC remained stable,(2)patient HC moved to a lower
percentile growth curve, and (3)patient HC moved to a higher
growth curve.
Results: Study population descriptive statistics were as
follows: mean age 9months, gender breakdown: 26% female and
74% male,and follow-up from 3 to 56months (mean 18months).
Subsets included: isolated sagittal synostosis(ISS)(59%),coronal
synostosis(18%),metopic(5%),lambdoidal(5%),and multiple suture
synostosis(MSS)(13%). ISS and MSS populations demonstrated
divergent outcomes. Eighty-nine percent of MSS patients moved
to higher HC percentile curves post-op,all experienced absolute
HC increases. 50% of ISS patients moved to a lower HC percentile
curve post-op,the only synostosis subset to do so. Remaining
ISS patients divided evenly among stable(27%) and increased(23%)
HC-percentile groups.
Conclusions: Serial HC measurement may meaningfully quantify
the efficacy and degree of surgical correction for craniosynostosis.
In MSS,multi-dimensional suture release may relieve restrictions
on normal brain development and correspond with increased
calvarial growth. The scaphocephalic deformity of ISS,by contrast,leads
to a disproportionately increased HC relative to cranial vault
volume preoperatively. Sagittal suture release restores a
more anatomic,spherical cranial vault volume relationship
and continued normal growth. Decreased percentile HC growth,as
demonstrated by our study population, may therefore represent
a successful surgical result in ISS patients.
Keywords:
craniosynostosis
calvarial growth
surgical treatment
Article ID: 40517
Abstract: 2006 Apr 24
Diagnosis and Management of Delayed Hyponatremia Following
Transsphenoidal Pituitary Surgery
Author(s):
Gabriel Zada, MD
Charles Liu, MD, PhD
Peter Singer, MD
Dawn Fishback, PA-C
Martin H. Weiss, MD (Los Angeles, CA)
Introduction: Delayed hyponatremia is frequently encountered
following transsphenoidal pituitary surgery. Asymptomatic
hyponatremia may occur more frequently than has been previously
suspected, yet may be amenable to outpatient intervention
in order to prevent the onset of symptoms.
Methods: 241 patients undergoing transsphenoidal pituitary
surgery at USC University Hospital had screening serum sodium
levels drawn as outpatients on postoperative day 7. Patient
records were reviewed to determine the incidence and risk
factors for hyponatremia.
Results: 23% of patients were found to be hyponatremic on
postoperative day 7. The majority (80%) were asymptomatic.
The incidence of symptomatic hyponatremia for all outpatients
was 5%. The mean sodium level of symptomatic patients was
120.5 mEq/L, compared with 128.4 mEq/L in asymptomatic, hyponatremic
patients (p less than 0.0001). Females were more likely to
develop hyponatremia than males (33% versus 22%, p less than
0.03). Patients with transient DI in the early postoperative
course were at greater risk for developing delayed hyponatremia
(52% versus 21%, p less than 0.001). Age, tumor type, and
tumor size did not correlate with the incidence of hyponatremia.
The majority of asymptomatic patients responded to outpatient
dietary modifications. 11 symptomatic patients were readmitted-
all responded to fluid restriction with or without intravenous
hypertonic saline.
Conclusions: Delayed hyponatremia occurs more frequently
than has been previously suspected following transsphenoidal
surgery, yet the majority of patients remain asymptomatic.
A serum sodium value obtained one week following surgery on
an outpatient basis is beneficial in the diagnosis, risk-stratification,
and implementation of preventative dietary correction of hyponatremia.
Keywords:
Pituitary
Hyponatremia
SIADH
Transsphenoidal
Article ID: 36009
Abstract: 2006 Nov 30
The Role of Neurosurgical Management in Children with
Langerhans Cell Histiocytosis
Author(s):
Laurence Davidson,MD, University of Southern California, Los
Angeles, CA
J. Gordon McComb,MD, Los Angeles, CA
Ira Bowen,BA, Los Angeles, CA
Mark D. Krieger,MD, Los Angeles, CA
Introduction: Langerhans cell histiocytosis (LCH) is a rare
disease whose course and optimal treatment are not fully known.
The goal of this study was to review a large series of LCH
patients with cranio-spinal lesions in order to assess the
long-term course, outcome and efficacy of treatment of the
disease.
Methods: Forty-four patients with LCH who presented to a
single pediatric neurosurgical department between 1976 and
2005 were retrospectively reviewed.
Results: This series included 29 boys and 15 girls, ranging
in age from 2 months to 13 years (average 5 years). The mean
follow-up was 4.5 years. Twenty-seven (61%) had unifocal bone
lesions, 12 (27%) had multifocal bone disease, 2 (4.5%) had
lesions in the hypothalamic-pituitary axis, and 3 (7%) had
multiple organ involvement. Five of the patients (17%) with
unifocal disease at presentation had subsequent development
of new lesions. Four of the patients (33%) with multifocal
bone disease at presentation had delayed development of new
lesions during the follow-up period. Two of the 3 patients
(66%) with multiple organ LCH died. Age less than 2 years
at the time of initial presentation was a risk factor for
both multifocality and dissemination.
Conclusions: This series of LCH patients demonstrates the
need for extent of disease evaluation both at presentation
and follow-up. Patients with unifocal LCH can be effectively
treated with surgery alone; however, systemic therapy should
be considered for dissemination. Very young patients are more
likely to have multifocal disease and diseminations, and will
usually require systemic therapy to control their disease.
Keywords:
Langerhans cell histiocytosis
Histiocytosis X
outcome analysis
pediatric neurosurgery
Article ID: 40440
Abstract: 2006 Nov 28
Aggressive Variant of Papillary Glioneuronal Tumor
Author(s):
Ramin J. Javahery,MD, Childrens Hospital Los Angeles, Los Angeles,
CA
J. Gordon McComb,MD, Los Angeles, CA
Laurence Davidson,MD, Los Angeles, CA
Ignacio Gonzalez,MD, Los Angeles, CA
Introduction: Papillary glioneuronal tumor (PGNT) was initial
described in 1998. A total of 23 cases have been reported.
All have had benign clinical courses. We are presenting two
patients with aggressive clinical courses.
Methods: A retrospective review of the case histories of
two patients with PGNT treated between 2000 and 2006 was undertaken.
The clinical histories, imaging studies, and histology were
reviewed. Previously published case reports/series were also
reviewed.
Results: Patient 1 was 13 years-old and patient 2 was 7 years-old,
both females. On MRI both lesions were large (5-9cm) cystic
tumors, with rim/nodular enhancement, minimal edema, and extension
to the ventricular system. The cyst fluid was hypointense
on T1 and hyperintense on T2 with faint septations. Patient
1 had a gross total resection while patient 2 had a sub-total
resection. The histology showed a bimodal population of cells.
A pseudopapillary area with a central hylanized vessel surrounded
by single layer of cells that stained for vimentin and GFAP
(astrocytic). A second portion containing variable sized cells
that stained for synaptophysin and PGP 9.5 (glial). Patient
1 had multifocal recurrence 4 years after surgery. All lesions
resolved within 18 months with fractionated radiation and
chemothrapy (temador). Patient 2 had progression of residual
disease within 3 months of resection. The proliferative indices
(Ki-67) were 5% and 4%, respectively. Previously cited proliferative
indices for PGNT's were <.5% to 3%.
Conclusion: We are reporting an aggresive variant of PGNT's
that is identical to previously described PGNT histologically
but with a higher proliferative index than previously described.
Keywords:
papillary glioneuronal tumor
aggressive
radiation
chemotherapy
Article ID: 40451
Abstract: 2006 Apr 24 Recurrent Endocrine-Inactive
Pituitary Adenomas: Initial Results and Long-term Outcomes after
Repeated Transsphenoidal Surgery
Author(s):
Edward F. Chang, MD
Jason S. Cheng, BS (San Francisco, CA)
Gabriel Zada, MD (Los Angeles, CA)
Charles B. Wilson, MD
Sandeep Kunwar, MD (San Francisco, CA)
Introduction: Outcomes after repeated transsphenoidal surgery
for recurrent/residual endocrine-inactive pituitary adenomas
(EIAs) are inadequately described.
Methods: We performed a retrospective review of all patients
with recurrent/residual EIAs operated at UCSF from 1975 to
1995. Primary outcome measures were initial extent of resection
and long-term tumor recurrence.
Results: Of 104 total patients, 85 were residual and 19 were
recurrent EIAs. The median time from initial surgery was 3.9
yrs. Suprasellar extension was observed in 58% and cavernous
sinus invasion in 23% of cases. Patients that underwent second
surgery were selected for analysis (N=92): 60 (65%) received
a subtotal resection (STR) and 32 (35%) had a gross total
resection (GTR). Thirty-nine patients (40%) received post-operative
radiotherapy. Multivariate predictors for STR were STR at
initial surgery (OR=5.7, 95%CI=1.7-19, P=0.004) and cavernous
sinus invasion (OR=2.7, 95%CI=1.5-8.0, P=0.02). Age, sex,
prior radiation, time from initial surgery, prior radiotherapy,
tumor size, and histopathological subtype were not associated
with STR. During a median follow-up of 5.25 yrs, 16 patients
in this cohort had a re-recurrence requiring a third transsphenoidal
removal. The total 5-year progression-free probability was
0.81. Cox regression analysis demonstrated that STR and no
post-operative radiation were independently associated with
increased recurrence (HR= 12, 95%CI 2.6-58, P=0.001; HR=8.2,
95%CI=2.1=31, P=0.001; respectively).
Conclusions: Even though transsphenoidal surgery for residual/recurrent
EIAs is associated with higher recurrence rates compared to
surgery for primary EIAs, it still offers good long-term tumor
control. Patients with STR of a recurrent EIA should be considered
for radiotherapy/radiosurgery.
Keywords:
pituitary adenoma
long-term outcome
endocrine-inactive
nonfunctioning
Article ID: 36283
Abstract: 2006 Apr 24
Use of Motor Evoked Potential Monitoring During Clip
Ligation of Anterior Circulation Aneurysms
Author(s):
James B. Elder, MD
Azadeh Farin, MD
Jerry Larsen, BS
Steven L. Giannotta, MD, FACS (Los Angeles, CA)
Introduction: Surgery for clip ligation of anterior circulation
aneurysms incurs a significant risk for new motor deficit
caused by ischemia to motor cortex or pathways during temporary
occlusion, permanent clipping or retraction. The standard
techniques for monitoring such ischemic changes is somatosensory
evoked potential (SSEP) monitoring. Transcranial motor evoked
potential (TcMEP) monitoring may improve detection of impending
ischemic changes intraoperatively.
Methods: Use of transcranial motor evoked potential (TcMEP)
monitoring was evaluated via retrospective chart review of
all cases of anterior circulation aneurysms clipped at this
institution since the consistent additional use of intraoperative
TcMEP monitoring. Initially 86 patients were considered; after
exclusion criteria were applied, 76 patients remained in the
analysis.
Results: Intraoperative electrophysiologic changes associated
with temporary clipping occurred in 18% (14/76) of patients.
Isolated TcMEP changes were seen in only one patient (1%)
and in association with SSEP changes in 6 patients (8%). SSEP
changes alone were seen in 7 patients. Signal changes returned
to baseline with removal of temporary clips in all patients
with TcMEP changes and all but one patient with SSEP changes.
Post-operative neurologic deficits were noted in 83% of patients
with changes in both modalities, 71% with TcMEP changes and
62% with SSEP changes.
Conclusions: The results suggest that TcMEP changes are more
likely to be associated with post-operative neurologic deficit,
especially if associated with SSEP changes. Therefore, intraoperative
transcranial motor evoked potential monitoring during aneurysm
surgery may offer improved prediction of ischemic changes
in cortical and subcortical areas responsible for motor function.
Keywords:
Aneurysm
Motor Evoked Potential
Article ID: 36008
Abstract: 2006 Mar 16
MRI morphologic predictors of SPECT positive facet arthropathy
in patients with axial back pain
Author(s):
keun-young A. Kim, MD
Michael Y. Wang, MD (Los Angeles, CA)
Introduction: While it is increasingly clear that facet arthropathy
is a significant contributor to axial back pain, a major barrier
to understanding this disease has been the lack of studies
elucidating the relationship between structural degenerative
facet changes and evidence of active joint inflammation. This
study investigates structural (MRI) characteristics that predict
pathology on functional (SPECT) imaging.
Methods: 431 patients without spondylolisthesis underwent
SPECT imaging for chronic back pain. 31 patients had at least
one “hot lesion." Exclusion of areas affected by
surgery yielded 32 positive joints out of a total of 230 facets.
Qualitative features were evaluated, including synovial and
cartilaginous discontinuities, heterogeneous bone patterns,
synovial hooking, and cupping osteophyte formation in the
lateral joint. Quantitative features were evaluated, including
asymmetry in size, joint space narrowing, lateral & medial
synovial content, and variations in synovial signal intensity.
Results: The MRI characteristic with the greatest sensitivity
was synovial space obliteration or narrowing (0.93 sensitivity
and 0.35 specificity). Several facet morphologies were highly
specific but not sensitive: lateral cupping from osteophytic
overgrowth (0.90), and synovial mottling (0.90). Facet asymmetry
and enlargement correlated poorly (sensitivity & specificity
= 0.50), suggesting that joint hypertrophy may be protective
and represent a more advanced stage in natural history of
joint degeneration.
Conclusions: Abnormal synovial patterns were the best predictors
of “hot” facets. This study suggests that specific
abnormalities in the bony, cartilaginous, and synovial architecture
may give future insight into the pathophysiology of facetogenic
pain syndromes and the natural history of facet degeneration
from synovial degeneration to facet enlargement.
Keywords:
degenerative
facet
SPECT
pain
Article ID: 34644
Abstract: 2006 Feb 18
Temporary Clip Time in Intracranial Aneurysm Surgery:
Correlation with Changes in Electrophysiologic Monitoring and
Postoperative Neurologic Deficit
Author(s):
Azadeh Farin, MD
James B. Elder, MD
Jerry Larsen, MS
Steven L. Giannotta, MD (Los Angeles, CA)
Introduction: The risk of focal infarction and postoperative
neurologic deficit secondary to induced temporary occlusion
of local arterial flow during microsurgical dissection of
anterior circulation aneurysms was analyzed. The correlation
between temporary clip time and electrophysiologic data, as
well as with postoperative infarct, was studied.
Methods: Anterior circulation aneurysms clipped at this institution
since using motor evoked potentials (MEPs) were retrospectively
reviewed. Of 86 cases performed 2003-5, 55 included temporary
clips. Patients with and without changes in electrophysiologic
monitoring and postoperative infarctions were compared based
on temporary clip time.
Results: Intraoperatively, five patients had MEP changes
and ten patients had SSEP (somatosensory evoked potential)
changes. Sixteen percent suffered infarction, and 25% demonstrated
a focal neurologic deficit within 24 hours postoperatively.
The mean temporary occlusion time was 10 minutes for patients
without infarction versus 13 minutes for patients with infarction.
80% of MEP changes and 70% of SSEP changes occurred at 11
minutes or greater of temporary clip time. Of those without
MEP changes, 57% had less than 11 minutes clip time. Of those
without SSEP changes, 61% had less than 11 minutes clip time.
Only 21% with less than 11 minutes occlusion exhibited postoperative
infarcts, compared with 35% of patients with 11 minutes or
greater occlusion. Conclusions: Surgery for clip ligation
of anterior circulation aneurysms is associated with an increased
risk for postoperative infarct and change in electrophysiologic
data due to ischemia secondary to temporary clip time of 11
minutes or greater. Reliable electrophysiologic monitoring
may limit deficits associated with prolonged temporary clip
time.
Keywords:
intracranial aneurysm
temporary clip time
electrophysiologic monitoring
postoperative neurologic deficit
Article ID: 33881
Abstract: 2006 Apr 25 Incidence of Radiographic
Imaging, Intracranial Injury, and Non-accidental Trauma Evaluation
in a Pediatric Emergency Department.
Author(s):
Daniel J. Hoh, MD
Mark D. Krieger, MD
Michael Tam, BA
J. Gordon McComb, MD (Los Angeles, CA)
Introduction: Head injury is a common presentation in children
suffering from non-accidental trauma (NAT). Radiographic imaging,
if demonstrating intracranial injury, may increase suspicion
for NAT. The objectives of our study were to assess: 1) the
frequency of imaging in children with head trauma 2) the incidence
of positive radiographic findings of intracranial injury,
3) the occurrence of NAT evaluation in patients with or without
evidence of intracranial injury.
Methods: We reviewed 475 consecutive records of patients
presenting to a children’s emergency room in a 5 month
period with the diagnosis of “head injury,” “head
trauma,” “fall,” or “suspected child
abuse.” Head CT and skull x-ray findings were recorded.
NAT evaluation (skeletal survey, ophthalmologic exam) and
notification of the Suspected Child Abuse and Neglect (SCAN)
team were reported.
Results: Head CT or skull x-rays were performed in 176 of
475 patients (36%). 32 of 176 (18%) had evidence of skull
fracture; 26 of 176 (15%) demonstrated intracranial injury.
41 (9%) underwent evaluation for NAT (25 skeletal surveys,
4 ophthalmologic exams, 29 SCAN investigations). 2 of 25 skeletal
surveys showed other injuries. 1 of 4 ophthalmologic exams
found retinal hemorrhages. 34 of 41 patients (83%) investigated
for NAT had a negative head CT or no brain imaging. Only 3
of 29 (10%) patients referred for SCAN team investigation
had a positive head CT.
Conclusions: Radiographic evidence of intracranial injury
in pediatric head trauma is uncommon. The absence of radiographic
findings, however, does not preclude the need for NAT evaluation
if clinical suspicion warrants further investigation.
Keywords:
pediatric
head injury
non-accidental trauma
radiographic imaging
Article ID: 36208
Abstract: 2006 Apr 24
In Vivo Response to an Artificial Extracellular Matrix
Protein
Author(s):
Chris Heller, MD
Carol Miller, MD
Cheryl Lin, MD
Dennis Leung, (Los Angeles, CA)
Julie Liu, BS
Paul Nowatzski, BS
David Tirrell, PhD (Pasadena, CA)
Charles Y. Liu, MD, PhD (Los Angeles, CA)
Introduction: Advanced biomaterials offer the promise of
specific signaling interactions with living tissue. We have
developed an artificial extracellular matrix (AECM) protein
designed to engineer the environment of the cell and influence
its fate. This study examines the in vivo immunological response
to this protein.
Methods: Thirty-six Sprague-Dawley rats were divided into
three cohorts. The “AECM” and “Silastic”
cohorts underwent subcutaneous implantation of an AECM protein
and silicone elastic, respectively. The “sham”
cohort underwent skin incision without implantation. Animals
were sacrificed at 1, 4, or 12 weeks. Tissue from each lesion
was fixed in 10% formalin and stained with hematoxylin and
eosin.
Results: At 1 week, the AECM cohort showed both lymphocytic
and foreign body giant cell infiltrates compared to fibrosis
and chronic inflammation in the Silastic cohort. The sham
cohort showed acute and chronic inflammation with early fibrosis.
Inflammatory response in the AECM cohort increased at 1 month
before finally diminishing to resemble that of the Silastic
cohort, which, along with the sham group, had not changed
significantly since the original samples. The amount of AECM
protein remaining after 1 month was 30% and after 3 months
0%. The amount of Silastic did not diminish over time.
Conclusions: The subcutaneous inflammatory response to our
AECM protein is, initially, more pronounced than with Silastic
and leads to early degradation of the material. Loss of the
implant over time may or may not be a detrimental quality.
Whether a similar response would be seen in neural tissue
has not been determined.
Keywords:
Artificial Protein
Biomaterials
Extracellular Matrix
In Vivo Response
Article ID: 36036
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