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Suboccipital craniectomy and duraplasty for Arnold

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Suboccipital craniectomy and duraplasty for Arnold
Arq Bras Neurocir 30(3): 110-5, 2011
Suboccipital craniectomy and duraplasty
for Arnold-Chiari malformation 1:
experience with 26 patients
Fabiana Policarpo1, Jose Carlos Lynch1, Celestino Esteves1,
Ricardo Andrade1, Vicente Temponi1
Hospital Federal dos Servidores do Estado, Rio de Janeiro, RJ, Brasil.
ABSTRACT
Objective: Observe whether the suboccipital foramen magno decompression, duraplasty
and microsurgery lyses of arachninodal bands are a safe and an effective treatment. Method:
A retrospective study was carried out with 26 consecutives patients with CM1 malformations
diagnosed, evaluated and operated at the Neurosurgical department of Servidores do Estado Hospital
(HSE), from 1986 to 2010. The radiological studies, patient records, surgical descriptions, and when
available, surgical videos, were reviewed, creating a database from which information pertinent to
the present study was collected. The follow-up varied from 8 to 168 months (mean, 48 months).
Results: Twenty-six patients underwent posterior fossa decompression with duraplasty. In this
series, there is no operative death. We noticed beneficial outcome in 69.2% of patients, and 4 cases
of transient postoperative complications. Conclusion: This experience with 26 cases CM1 proved
that suboccipital craniectomy; duraplasty with autologus pericranium and microlysis of adhesions
is a safe and effective procedure.
KEYWORDS
Decompression surgical, Arnold-Chiari malformation/physiopathology, Arnold-Chiari malformation/
surgery, syringomyelia.
RESUMO
Craniectomia suboccipital e duroplastia para o tratamento da malformação de Arnold-Chiari
tipo 1: experiência com 26 pacientes
Objetivo: Observar se a descompressão cirúrgica do forâmen magno associada à duroplastia é um
procedimento seguro e eficaz para o tratamento da malformação de Arnold-Chiari tipo 1. Método:
Realizaram-se revisão retrospectiva dos prontuários, descrições cirúrgicas e imagens de 26 pacientes
com malformação de Arnold-Chiari 1 operados no Hospital dos Servidores do Estado (HSE) no período
entre 1996 e 2010. Resultados: O tratamento em 18 pacientes (68%) constitui-se de craniectomia
suboccipital, remoção do arco posterior de C1 e duroplastia. Os mesmos procedimentos foram
acrescidos de laminectomia de C2 em 8 indivíduos (32%). Nesta série, não ocorreu nenhum óbito
cirúrgico e observou-se melhora sintomática em 68% dos pacientes. Conclusão: A craniotomia occipital
com a remoção do arco de C1 e/ou laminectomia de C2 e duroplastia mostrou-se eficaz, com baixa
morbidade e sem mortalidade.
PALAVRAS-CHAVE
Descompressão cirúrgica, malformação de Arnold-Chiari/fisiopatologia, malformação de ArnoldChiari/cirurgia, siringomielia.
Introduction
The Chiari malformation 1 (CM1) is regarded as a
pathological hindbrain maldevelopments characterized
by downward herniation of the cerebellar tonsils at least
3 to 5 mm below the foramen Magnum.4,10,22
There has been open debate on the best operative
treatment of this disease. Ellenbogen et al.5 described over
20 different practiced operations directed at CM1, but the
optimal surgical management of CM1 is still unclear. Nowadays there is two main accepts techniques to treat the CM1:
suboccipital decompression with duraplasty (PFDD) and
suboccipital decompression without duraplasty (PFD).3,8,9,1118,20,23,24,26-28
This paper presents our experience with suboccipital decompression with duraplasty and microsurgery
lyses of arachninodal bands in 26 consecutives patients.
Material and method
A retrospective study was carried out with 26 consecutives patients with CM1 diagnosed, evaluated and
operated at the Neurosurgical Department of HSE, from
1. Neurosurgical Department of Hospital Federal dos Servidores do Estado, Rio de Janeiro, RJ, Brazil.
Arq Bras Neurocir 30(3): 110-5, 2011
1996 to 2010. The radiological studies, patient records,
surgical descriptions, and when available, surgical
videos, were reviewed, creating a database from which
information pertinent to the present study was collected.
The follow-up varied from 8 to 168 months (mean, 48
months). This paper is a retrospective study; it has inherent biases and drawbacks; only a large prospective
study can overcome this weakness.
Surgical procedure: In all cases the same microsurgery technique was used, following these general
steps: general anesthesia with a carefully endotracheal
intubation, then the patient is carefully placed in ventral
decubitus position resting on the thoracolumbar support,
and the head placed in the Mayfield. The procedure starts
with the use of a 4,5x loupe and co-axial lightning. With
a scalpel, a rectilinear midline incision is made starting
in the superior occipital line and extending down to C3/
C4 level. The fascia is opened in midline with a scalpel
and the paravertebral muscles are carefully disinserted
and laterally retracted with a periosteum elevator. With
the autostatic retractors the exposure and the suboccipital scama, the posterior arch of C1 and the spinous
processes and lamina of the C2 are visualized. Removal
of the posterior arch of C1 is performed with the use of
air drill and Laksell rongeur, if the cerebellar tonsils are
at or bellow C2, the spinous processes and lamina of the
C2 is removed as well. We perform a limited suboccipital
craniectomy (4 x 4 cm) to enlarge the foramen magnum
(FM) and allow for both decompression and maintenance of the posterior fossa neural elements.
During the whole procedure, careful hemostasia is
performed with bipolar forceps under saline irrigation
to keep the field bloodless, to prevent adhesions that can
be induced around the spilled blood. At this moment,
surgical microscope is introduced, and using a 10 to 16x
magnification the dura mater is sectioned in Y-shaped
fashion allowing access to neural element. The free
border of the dura mater is sutured in the paravertebral
musculature. Following, we made the microlysis of the
adhesions that involves the brainstem, spinal cord and
posterior inferior artery with extremely care to lyses only
the adhesions without damage functional tissue or vessels, avoiding complications and, if necessary, the reduction or amputation of cerebelar tonsils, establishing an
outlet for the forth ventricule. Duraplasty is performed
with pericranium to prevent straitening of the dural sac
diameter and adhesions to the medulla or spinal cord.
(Figures 1 A, B, C and D e Figures 2 A, B, C and D)
Valsalva maneuver is performed aiming to detect the
existence of a cerebral spinal fluid (CSF) leakage, which is
sutured if present. Biological glue has been recently used
on the suturing line with the purpose of preventing CFS
fistula. The closure of the paravertebral musculature and
fascia is performed in 3 planes to prevent muscle atrophy
and cervical pain; the skin is sutured with 3.0 nylon.
Suboccipital craniectomy and duraplasty for Arnold-Chiari malformation 1
Policarpo F et al.
Figure 1 – (A) Preoperative sagital T1 MR imaging demonstrating
cerebellar tonsil herniation through the FM. (B) Postoperative
sagital T2 imaging after FM decompression and partial reduction
of cerebelar tonsils, showing the CSF around brainstem and
cerebellum, indicating that adequate decompression was achieved.
(C) Operative image of the same patient demonstrating herniation
of both cerebellar tonsils through the FM. (D) Operative image
after partial subpial aspiration of cerebellar tonsils and lyses of
adhesion, revealing reduction of the tonsils size and the spinal
medullary junction.
111
Arq Bras Neurocir 30(3): 110-5, 2011
Figure 2 – (A) Sagital T2 RM revealing CM with compression of brainstem and syringomyelia (arrow). (B) Post-operative T2 RM showing
foramen magno decompression and decreased of the syringomyelia (arrows). (C) Intraoperative photographs demonstrating herniation of
both tonsils. (D) Operative view of the posterior inferior artery, after tonsillectomy.
Results
In this series, there were 14 men and 12 women
ranging in age from 5 to 72 years (Figure 3).
The duration of the symptoms varied from 2 months
to 14 years (Figure 4). The signs and symptoms can be
appreciated in the table 1.
The syringomyelia was present in 10 individuals
(38.4%). Scoliosis was detected in 6 patients (23%). We
diagnosed 4 cases (15%) of basilar invagination; one
of them needed a trans oral odontectomy followed by
posterior fixation.
Eighteen patients (69.2%) underwent posterior fossa
decompression and removal of the posterior arch of
C1 with duraplasty. In 8 patients (30.7%), because the
cerebelar amygdales reach the level of C2, we added
C2 laminectomy. In 6 (23%) patients, we added tonsillectomy to improve the CSF flow.
112
There is no operative death in this series, but occurred 4 (15.3%) cases of postoperative transient complications without definitive neurological repercussion:
one case of meningitis was cured with antibiotics. One
patient developed CSF fistula that needed operative closured, another one with postoperative cerebellar ptosis
needed cranioplasty, and a case of pseudo meningocele
that resolved without further treatment.
During the follow up, we observed early beneficial outcome in 18 patients (69.2%), stabilization of the disease in
8 individuals (30.7%). Of this group, 6 (23.3%) showed late
deterioration. In 10 patients diagnosed with syringomyelia
only 3(30%) had a sustained improvement, as oppose as
in the individuals without syringomyelia that present a
permanent improvement in 10 individuals (62.5%) of the
cases. Two patients died for clinical problems not related
to CM1. One died of upper GI bleeding 3 years after the
surgery and the other died of pulmonary cancer.
Suboccipital craniectomy and duraplasty for Arnold-Chiari malformation 1
Policarpo F et al.
Arq Bras Neurocir 30(3): 110-5, 2011
9
8
7
6
5
4
3
2
1
0
8
5
2
1
5-10
6
2
11-20
21-30
31-40
41-50
51-60
1
61-70
1
71-80
Figure 3 – Bar graphs revealing the age of 26 patients with CM1.
5
5
< 12
13 to 24
25 to 36
37 to 48
49 to 60
> 60
2
2
2
8
Figure 4 – Pie chart showing duration of signs and symptoms
(in months) of 26 patients with CM1.
Table 1 – Sing and symptoms of 26 patients with CM1
n
%
Pararesis
16
64
Hiperreflexia
13
52
Babinski
12
48
Arms paresis
12
48
Headache
12
48
Ataxia
11
44
Disestesias
11
44
Nistagmo
4
16
Dismetria
3
12
Hands muscle atrophy
2
8
Torcicolo
2
8
S. Horner
2
8
Disartria
2
8
Disfagia
2
8
Diplopia
2
8
Discussion
There are several mechanisms to explain pathogenenesis of syringomyelia5,7 but this is discussion is
beyond the scope of this article.
There has been open debate on the best operative
treatment of this disease.3,6,8,9,11-18,20,23,24,26-28
Suboccipital craniectomy and duraplasty for Arnold-Chiari malformation 1
Policarpo F et al.
The majority published series showed the benefits of
the association of suboccipital craniectomy to enlarge
the FM and duraplasty in achieving good surgical
results.1,2,5,6,8,13-15,19-21,23,24,26-28
But duraplasty and intradural manipulation have
been associated with morbidity in certain series and
some surgeons are advocating bony decompression
only, as there appears to be a subset of patients who
respond to this more simple intervention.3,9,11,13,14,24,28
The literature shows a low complication rate after non
duraplasty decompression, but several patients submitted to bony decompression alone did not improved and
needed reoperations.5,13,16
The advantage of opening the dura is that it provides
the necessary exposure to allow the microlysis of the
adhesions that involves the brainstem, spinal cord and
posterior inferior artery and if necessary the reduction
or tonsillectomy. The microlysis of the adhesion is an
important part of surgery. We are not in agreement with
the authors who claim that a carefully performed microsurgery intradural operation creates more scarring
and subsequent failure than an extradural procedure.
Bindal et al.2 concluded that symptoms secondary
to brain stem compression seemed reversible with decompressive surgery with duraplasty, whereas results
with syringomyelia were much less dramatic with the
same procedure.
Saez et al.21 presented the surgical decompression
and duraplasty experience of 60 cases. They reported
beneficial outcome in 65% of adult patients. The incidence and quality of postoperative improvement were
greater initially but tended to decrease after several
years.
In the experience of Paul et al.18, 69 patients underwent suboccipital craniectomy and C 1-3 laminectomy.
In addition to the decompression, a fascial graft was
interposed between the edges of the dural incision.
They reported early improvement of the preoperative
symptoms in 82% of patients.
Tubbs et al.26,27 recommend that patients with CM1
and syringomyelia undergo a decompressive surgery
and duraplasty, if the veils are present, they should be
fenestrate.
Milhorat and Bolognese13 and Milhorat et al.14 report
that the most effective procedure with minimal complications has been a tailored osseous decompression
of the craniocervical junction, duraplasty employing
autologus pericranium, and microlysis of arachnoidal
adhesions and tonsillar shrinkage as determined by
intraoperative color Doppler ultrasonography.
McGirt et al.12 advocated decompression with duraplasty only for the patients with tonsillar herniation to or
bellow C2 and in the cases with associated syringomyelia. They used ultrasound in 279 cases of suboccipital
113
Arq Bras Neurocir 30(3): 110-5, 2011
and C1 bony decompression alone, normal systolic
pulsation of the tonsils and expansion of subarachnoid
space was observed in 46% of the patients.
Mutchnick et al.16 performed a review of CM1 decompressions in 121 patients, 56 underwent PFD and
64 patients underwent PFDD. Of the 56 PFD patients,
7 (12.5%) needed a subsequent PFDD for symptomatic
recurrence and they concluded PFD was associated
with a higher rate of repeated decompression but they
believe that may be justified by the significantly lower
morbidity rate.
Furtado et al.6 preferred a durotomy in addition to
bone decompression at the FM. This preference, they
believe, is based in the presence of arachnoidal veils
at the foramen of Magendie that also contribute to
obstruction of CSF flow at the FM.
Among Us, Silva et al.8 preferred a craniectomy,
aspiration of the tonsils and dural graft, creating a large
cisterna magna. Taricco e Melo25 performed PFDD plus
fourth ventricule shunting in 29 individuals. They noticed improvement in 84% of them. Romero e Pereira20
operated 6 patients with PFD and 10 with PFDD and
suggested that patients with syringomyelia may have a
higher like hood of improvement after PFDD.
The aforementioned studies clearly showed that
optimal surgical management of CM1 is still unclear.
This current experience with 26 cases of CM1 with
suboccipital craniectomy, duraplasty with autologus
pericranium and microlysis of adhesions proved a safe
and effective procedure with symptomatic improving
of 69.2%, result similar to others published series in
the literature.2,16,18,21 In patients with syringomyelia, we
observed that the improvement were much less dramatic
with the same procedure. To date, there is no a clear
answer if the patients, after an adequate FM decompression, but with a maintained syringomyelia should be
reoperated and which procedure should be done. We
did not reoperated a single patient with a maintained
syringomyelia.
duraplasty is an interesting new area of research with potentially important clinical implications, but more work
is necessary before definitive conclusions can be made.
References
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Conclusion
The neurosurgeon can elect either PFDD or PFD as
the appropriate treatment, but the surgery must enlarge
the foramen magnum and allow for both decompression
and maintenance of the posterior fossa neural elements
and reestablish the CSF flow. A further investigation is
needed to define with clarity which surgery is better for
a specific individual. What is appropriate for one patient
is not necessarily appropriate for other.
The use of color Doppler US during surgery to taylor
the foramen Magno decompression and the necessity of
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13.
14.
15.
16.
Alden TD, Ojemann JG, Park TS. Surgical treatment of Chiari
I malformation: indications and approaches. Neurosurg
Focus. 2001;11(1):E2.
Bindal AK, Dunsker SB, Tew JM Jr. Chiari I malformation:
c l a s s i f i c a t i o n a n d m a n a g e m e n t . N e u ro s u rg e r y.
1995;37(6):1069-74.
Caldarelli M, Novegno F, Vassimi L, Romani R, Tamburrini G,
Di Rocco C. The role of limited posterior fossa craniectomy
in the surgical treatment of Chiari malformation type I:
experience with a pediatric series. J Neurosurg. 2007;106(3
Suppl):187-95.
Carmel PW, Markesbery WR. Early descriptions of the
Arnold-Chiari malformation. The contribution of John
Cleland. J Neurosurg. 1972;37(5):543-7.
Ellenbogen RG, Armonda RA, Shaw DW, Winn HR.
Toward a rational treatment of Chiari I malformation and
syringomyelia. Neurosurg Focus. 2000;8(3):E6.
Furtado SV, Thakar S, Hegde AS. Correlation of functional
outcome and natural history with clinicoradiological factors
in surgically managed pediatric Chiari I malformation.
Neurosurgery. 2011;68(2):319-27.
Gardner WJ, Angel J. The mechanism of syringomyelia
and its surgical correction. Clin Neurosurg. 1958;6:131-40.
Silva JA, Melo LR, Araújo AF, Santos Jr AA. Resolution
of syringomyelia in ten cases of “up-and-down Chiari
malformation” after posterior fossa decompression. Arq
Neuropsiquiatr. 2010;68(5):694-9.
James HE, Brant A. Treatment of the Chiari malformation
with bone decompression without durotomy in children and
young adults. Childs Nerv Syst. 2002;18(5):202-6.
Koehler PJ. Chiari’s description of cerebellar ectopy (1891).
With a summary of Cleland’s and Arnold’s contributions
and some early observations on neural-tube defects. J
Neurosurg. 1991;75(5):823-6.
Krieger MD, McComb JG, Levy ML. Toward a simpler
surgical management of Chiari I malformation in a pediatric
population. Pediatr Neurosurg. 1999;30(3):113-21.
McGirt MJ, Attenello FJ, Datoo G, Gathinji M, Atiba A,
Weingart JD, et al. Intraoperative ultrasonography as a
guide to patient selection for duraplasty after suboccipital
decompression in children with Chiari malformation type I.
J Neurosurg Pediatr. 2008;2(1):52-7.
Milhorat TH, Bolognese PA. Tailored operative technique
for Chiari type I malformation using intraoperative color
Doppler ultrasonography. Neurosurgery. 2003;53(4):899905; discussion 905-6.
Milhorat TH, Chou MW, Trinidad EM, Kula RW, Mandell M,
Wolpert C, et al. Chiari I malformation redefined: clinical
and radiographic findings for 364 symptomatic patients.
Neurosurgery. 1999;44(5):1005-17.
Munshi I, Frim D, Stine-Reyes R, Weir BK, Hekmatpanah
J, Brown F. Effects of posterior fossa decompression with
and without duraplasty on Chiari malformation-associated
hydromyelia. Neurosurgery. 2000;46(6):1384-9.
Mutchnick IS, Janjua RM, Moeller K, Moriarty TM.
Decompression of Chiari malformation with and without
Suboccipital craniectomy and duraplasty for Arnold-Chiari malformation 1
Policarpo F et al.
Arq Bras Neurocir 30(3): 110-5, 2011
17.
18.
19.
20.
21.
22.
23.
duraplasty: morbidity versus recurrence. J Neurosurg
Pediatr. 2010;5(5):474-8.
Oldfield EH, Muraszko K, Shawker TH, Patronas NJ.
Pathophysiology of syringomyelia associated with Chiari
I malformation of the cerebellar tonsils. Implications for
diagnosis and treatment. J Neurosurg. 1994;80(1):3-15.
Paul KS, Lye RH, Strang FA, Dutton J. Arnold-Chiari
malformation. Review of 71 cases. J Neurosurg.
1983;58(2):183-7.
Rhoton AL Jr. Microsurgery of Arnold-Chiari malformation
in adults with and without hydromyelia. J Neurosurg.
1976;45(5):473-83.
Romero FR, Pereira CA. Suboccipital craniectomy with
or without duraplasty: what is the best choice in patients
with Chiari type 1 malformation? Arq Neuropsiquiatr.
2010;68(4):623-6.
Saez RJ, Onofrio BM, Yanagihara T. Experience with
Arnold-Chiari malformation, 1960 to 1970. J Neurosurg.
1976;45(4):416-22.
Salomão JF, Bellas AR, Leibinger RD, Barbosa AP, Brandão
MA. [Symptomatic Chiari type II malformation]. Arq
Neuropsiquiatr. 1998;56(1):98-106.
Schijman E, Steinbok P. International survey on the
management of Chiari I malformation and syringomyelia.
Childs Nerv Syst. 2004;20(5):341-8.
Suboccipital craniectomy and duraplasty for Arnold-Chiari malformation 1
Policarpo F et al.
24.
25.
26.
27.
28.
Stevenson KL. Chiari Type II malformation: past, present,
and future. Neurosurg Focus. 2004;16(2):E5.
Taricco MA, Melo LR. Retrospective study of patients with
Chiari: malformation submitted to surgical treatment. Arq
Neuropsiquiatr. 2008;66(2A):184-8.
Tubbs RS, McGirt MJ, Oakes WJ. Surgical experience in 130
pediatric patients with Chiari I malformations. J Neurosurg.
2003;99(2):291-6.
Tubbs RS, Smyth MD, Wellons JC 3rd, Oakes WJ.
Arachnoid veils and the Chiari I malformation. J Neurosurg.
2004;100(5 Suppl Pediatrics):465-7.
Yeh DD, Koch B, Crone KR. Intraoperative ultrasonography
used to determine the extent of surgery necessary during
posterior fossa decompression in children with Chiari
malformation type I. J Neurosurg. 2006;105(1 Suppl):26-32.
Endereço para correspondência
José Carlos Lynch
Rua Jardim Botânico, 600/605
22461-000 – Rio de Janeiro, RJ, Brasil
E-mail: [email protected]
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