Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_4368_Библиотеки_им_академика_М_И_Перельмана
.pdf
The “Far Medial” (Transcondylar/Transtubercular) Approach to the Inferior Third of the Clivus
https://t.me/med1917
Further dissection superomedially within the jugular
tubercle, along with further removal of clival bone more
superiorly, gives the operator access to the Dorello’s canal
and the abducens nerve. Likewise, the resection of more
bone in the inferior one-third of the clivus will afford
access to the dura of the foramen magnum. Tumors in the
foramen magnum with more lateral extensions are accessed through expansion of the transtubercular approach.
22.2 Complications, Tips and
Tricks
• One of the first steps in accessing the transcondylar
window is entering the ipsilateral parapharyngeal
space. The key to this is removal of the ipsilateral in-
ferior turbinate and maxillectomy. This is followed by
mobilizing the ET orifice medially. To create a space
between the carotid artery and the ET, the endoscopic
scissors are inserted vertically just lateral to the ET. At
this vertical position, a cut at the level of the foramen
lacerum would injure the petrous carotid artery. To
prevent this, the scissors are rotated from a vertical to a
horizontal position to transect the ET.
• When performing the nasopharyngectomy, one will
ob
serve that the nasopharyngeal mucosa is extremely
adherent to the underlying muscle. Various tools can
be implemented to effectively separate the mucosa,
including the use of cautery, Kerrison forceps, and/or
microdebrider.
• When dividing the basopharyngeal fascia, it is
imperative to observe that the fascia is laterally
continuous with the cartilaginous ring around the
lacerum segment of the carotid artery. Thus, careful
separation and dissection of the fascia is required to
prevent injury to the artery.
• When we identify the ipsilateral medial pterygoid
pla
te, the mucosa over the plate is often stripped away.
By doing so, the inferior turbinate artery often will
bleed and will require quick cauterization.
• Lesions located within the hypoglossal canal often
require significant but careful drilling of the supracondylar groove. Target-centric image guidance is
often required to effectively drill the anteroinferior
and medial portion of the condyle, in the area of the
hypoglossal canal. Contrary to the anterior aspect of
the canal, which can be fairly liberally drilled away,
the posterolateral aspect should not be drilled as
much, as this may cause removal of more than half
of the occipital condyle, resulting in spinal instability at the AO joint. Therefore, in general, the plane of
the hypoglossal canal should not be transgressed. To
mitigate this, we can access the ventromedial aspect
of the occipital condyle to create a lateral corridor
and still preserve a majority of the occipital condyle
and synovial joint capsule.
22.3 Case Example
To demonstrate the clinical applicability of our anatomic approach to the inferior third of the clivus and
the transcondylar/transtubercular area, we describe
here a case of a 66-year-old woman who presented to
the clinic for evaluation of a recurrent chordoma. The
patient initially complained of nasal stuffiness, possible sinus infection, and clear rhinorrhea, which has
been increasing over a period of 3 months. Imaging
revealed a large heterogeneously enhancing mass centered in the sphenoid sinus and clivus. The mass extended superiorly to the level of the sella turcica and
inferiorly to the level of the superior articular facet of
C1 (Figs. 22.8–22.10). As such, a decision was made to
undergo surgical resection via the expanded endoscopic endonasal approach.
Intraoperatively, a pedicled lateral wall flap (pedicle:
sphenopalatine artery branch) was created for
reconstruction and subsequently stored in the maxillary
sinus, following a wide maxillectomy. In addition, to fully
cover the nasal septum postoperatively, a reverse donor
flap, with the pedicle being a branch of the ethmoidal artery, was created. Tumor resection was then performed
by sequentially following the steps mentioned earlier. We
first identified the medial pterygoid plate as a starting
point for entrance into the transcondylar window. Next,
the hypoglossal canal was visualized and tumor was resected around it. Both carotid arteries were identified
but seemed dehisced. Further tumor resection was performed along the palatovaginal canal, both vidian canals,
and the foramen rotundum. The sphenopalatine canal
was then identified and further tumor was resected. The
entire base of the clivus was then subsequently drilled
to leave a thin cortical layer of bone. Finally, the occipital
condyle was visualized and accessed ventromedially to
remove residual tumor (Figs. 22.11 and 22.12).
No intraoperative and postoperative complications
were noted.
22.4 Conclusion
EEA affords direct access to the inferior one-third of
the clivus and the anterior foramen magnum. Lesions
either arising from or extending to the lateral aspect of
the inferior one-third of the clivus require the additional exposure and resection of the jugular tubercle and/or
the medial occipital condyle. The correspondence of this
endonasal approach to the “far lateral” open skull base
approach led to our original description of this approach
as the “far medial” approach. This “far medial” approach
can allow access to the hypoglossal canal, medial jugular foramen, the superior aspect of the vertebral artery,
or the lateral aspect of the foramen magnum. Critically,
the supracondylar groove is the anatomic landmark for
the hypoglossal canal, which divides the area into the
jugular tubercle superiorly and the occipital condyle inferiorly. Spinal stability is preserved by resecting only
the ventromedial aspect of the occipital condyle and
corresponding joint capsule, respecting the plane of the
hypoglossal canal, and resection of bone only on the anterolateral but never the posterolateral face of the hypoglossal canal. A wide variety of benign or malignant
lesions can be accessed using this “far medial” approach
for biopsy, nerve decompression, or, in certain situations,
complete tumor removal.
235
The “Far Medial” (Transcondylar/Transtubercular) Approach to the Inferior Third of the Clivus
https://t.me/med1917
PreOp PreOp
*
JF
ab
cd
Hypoglossal
PreOp PostOp
PreOp
Vidian
PostOp
ef
Fig. 22.8 Axial CTA preoperative imaging anatomy. (a) Prevertebral component of mass that partially eff aces the fossa of Rosenmüller
at the level of hypoglossal canal (arrow). Asterisk, internal carotid artery; JF, jugular foramen. (b) The right vidian canal (arrow) has been
displaced laterally as a result of osseous remodeling by tumor, compared with the left vidian canal (arrow). Preoperative coronal CTA
(c) and canal and sagittal T1-weighted MRI postcontrast (e) at the level of vidian showed heterogeneous mass fi lling the sphenoid sinus
that extends anteriorly to invade the posterior nasal septum, superiorly extending to the level of the sella turcica, inferiorly to the anterior
arch C1 (asterisk), and superior articular facet (not shown) and posteriorly to the posterior cortex of the clivus (arrows in e indicate limits
of tumor). There was also involvement and eff acement of the fossa of Rosenmüller (right more than left), both vidian canals and the left
petrous apex (not shown). Postoperative coronal CT (d) and sagittal T1-weighted MRI postcontrast (f) showed gross total resection of
tumor.
236
*
The “Far Medial” (Transcondylar/Transtubercular) Approach to the Inferior Third of the Clivus
https://t.me/med1917
SPA
Tum or
ET
MP
Fig. 22.11 Occipital condyle (OC) in view. ET, Eustachian
Fig. 22.9 Resection of the base of the medial pterygoid
muscle (MP) as an entry point to the transcondylar window. ET,
Eustachian tube; MP, medial pterygoid; SPA, sphenopalatine
artery.
ab
tube; FM, foramen magnum; SG, supracondylar groove; VN,
vidian nerve.
VN
SG
OC FM ET
Tum or
PVC
ET
IT
Suction
Pointer
c d e
Fig. 22.10a–e A simultaneous intraoperative endoscopic endonasal and image-guided neuronavigation view. The navigation probe
is placed in the fossa of Rosenmüller and a 15-mm off set (“look-ahead view”) provided in fi gures (a) and (b). Figure (d) provides a
view in a 90-degree plane to the plane of the tip of the pointer. Note that when looking at fi gures (a) and (b), this provides a direct
correlation and trajectory to the supracondylar groove (SG), and the orthogonal plane shows the view and the 360-degree anatomic
relationships of the SG. The orthogonal view (bottom right quadrant) displays the supracondylar groove in a trajectory-centric view.
The corresponding EEA view shows the position of the pointer and trajectory followed into the SG following transection of the ET. ET,
Eustachian tube; IT, inferior turbinate; PVC, palatovaginal canal.
237
The “Far Medial” (Transcondylar/Transtubercular) Approach to the Inferior Third of the Clivus
https://t.me/med1917
OC
OC
Fig. 22.12 A simultaneous endoscopic and image-guided view displaying the occipital condyle as a fi nal end point to the
transcondylar/transtubercular space. OC, occipital condyle.
References
1. Kassam AB, Gardner P, Snyderman C, Mintz A, Carrau R. Expanded
endonasal approach: fully endoscopic, completely transnasal approach to the middle third of the clivus, petrous bone, middle cranial fossa, and infratemporal fossa. Neurosurg Focus 2005;19(1):E6
2. Kassam A, Snyderman CH, Mintz A, Gardner P, Carrau RL. Expanded endonasal approach: the rostrocaudal axis. Part II. Posterior
clinoids to the foramen magnum. Neurosurg Focus 2005;19(1):E4
3. Kassam AB, Snyderman C, Gardner P, Carrau R, Spiro R. The expanded endonasal approach: a fully endoscopic transnasal approach and resection of the odontoid process: technical case report. Neurosurgery 2005;57(1, Suppl):E213, discussion E213
4. Nayak JV, Gardner PA, Vescan AD, Carrau RL, Kassam AB, Snyderman CH. Experience with the expanded endonasal approach for
resection of the odontoid process in rheumatoid disease. Am J Rhinol 2007;21(5):601–606
5. Benet A, Prevedello DM, Carrau RL, et al. Comparative analysis of
the transcranial “far lateral” and endoscopic endonasal “far medial” approaches: surgical anatomy and clinical illustration. World
Neurosurg 2014;81(2):385–396
6. Morera VA, Fernandez-Miranda JC, Prevedello DM, et al. “Far-medial” expanded endonasal approach to the inferior third of the
clivus: the transcondylar and transjugular tubercle approaches.
Neurosurgery 2010;66(6, Suppl Operative):211–219, discussion
219–220
7. Vishteh AG, Crawford NR, Melton MS, Spetzler RF, Sonntag VKH,
Dickman CA. Stability of the craniovertebral junction after unilateral occipital condyle resection: a biomechanical study. J Neurosurg 1999;90(1, Suppl):91–98
8. Kassam AB, Mintz AH, Gardner PA, Horowitz MB, Carrau RL, Snyderman CH. The expanded endonasal approach for an endoscopic
transnasal clipping and aneurysmorrhaphy of a large vertebral
artery aneurysm: technical case report. Neurosurgery 2006;59(1,
Suppl 1): ONSE162–165, discussion ONSE162–E165
238
3
Chapter 23
https://t.me/med1917
23.1 Indications 240
Jugular Foramen
Approach
23.2 Surgical Steps (Including
Tips and Tricks, Technique,
and Important Landmarks) 240
Jugular Foramen Approach
https://t.me/med1917
23 Jugular Foramen Approach
Muhamad A. Amine, Vijay K. Anand, Tomasz Dziedzic, Theodore H. Schwartz
Introduction
The jugular foramen (JF) is a complicated area to access
regardless of the approach or technique used. The endoscopic transmaxillary transpterygoid approach
extended to access the parapharyngeal space (PPS) and
JF contained therein.
strated here using a step-by-step cadaveric dissection.
It is important to understand the regional anatomy and
correlate it with the dissection, which requires wide
exposure starting with a broad septectomy to prevent
injury to vital structures. Using a 30-degree scope in
the contralateral naris allows for the most comfortable
positioning of instruments and optimal view of the
area of dissection. All documentation and illustrations
in this chapter were obtained using a 30-degree scope.
It should also be noted that all the images within this
chapter were obtained from the same cadaveric specimen on the left side. A secure attempt has been made
to obtain the images using the same point of view to
demonstrate a “flip-book” like series of images showing the stepwise dissection. However, once the PPS was
exposed, close-up images were taken to demonstrate
the detailed anatomy.
2,3
The technique will be demon-
1
can be
23.1 Indications
Endoscopic approach to the JF includes neoplastic lesions such as trigeminal schwannomas, nasopharyngeal cancers, juvenile angiofibromas, and meningiomas,
which extend to or invade the middle cranial or infratemporal fossa (ITF). The main benefit of this approach
is a direct approach which spares the risk of facial nerve
injury, temporomandibular and mandibular resection,
and middle and external ear obliteration as seen in the
traditional lateral approaches. However, the endoscopic
approach is not without its own potential morbidities
which stem from the resection of the pterygoid musculature and risk of injury to the intimate neurovascular structures including the carotid artery and cranial
nerves V, IX, X, XI, and XII as well as the sympathetic
chain as they emerge from the skull base within the PPS.
Nevertheless, the endonasal approach offers a direct
route to the jugular area and allows for the management
of the entire ITF and superior PPS.
wall, lateral wall, and roof of the maxillary sinus are
in view (Fig. 23.1).
• Next, the back wall of the maxillary sinus is removed
(Fig. 23.2). T
and ITF contents. The periosteal fascial layer is removed
and the internal maxillary artery is ligated carefully so
as not to injure the infraorbital nerve (ION) laterally
and superiorly. The ION serves as our landmark as it
courses posteriorly toward the infraorbital foramen. It
also gives and receives branches to the pterygopalatine
ganglion which lies within the PPF.
• To gain access to the posterior contents of the PPF and
ITF, the vascular and fatty contents of the anterior compartment are carefully removed (Fig. 23.3). This will
then expose two important muscles, the temporalis
muscle (TM) and the lateral pterygoid muscle (LPM).
Another important landmark that is exposed is the
buccal nerve (BN). The BN is found lying between the
TM and LPM. Following it posteriorly will lead you to
the foramen ovale (FO) and the root of the third division of the trigeminal nerve.
• Next, the inferior head of the LPM must be resected
(Fig. 23.4). The BN is seen running between the upper
and lower heads of the LPM.
• The lateral pterygoid plate (LPP) is then resect-
ed to reveal the medial pterygoid muscle (MPM)
(Fig. 23.4).
• T he LPP must be removed up to the skull base (Fig. 23.5).
This will expose the FO as it lies just posterior to it.
SPA
his exposes the pterygopalatine fossa (PPF)
ION
23.2 Surgical Steps (Including
Tips and Tricks, Technique, and
Important Landmarks)
• Create a wide septectomy to allow for a binostril ap-
proach. A 30-degree scope is placed in the contralateral side, while the instruments can be placed in
either side.
• The middle turbinate is removed and a medial max-
illectomy is performed down to the floor of the nose.
The inferior turbinate is also removed. The entire back
240
Fig. 23.1 Left maxillary sinus. The inferior and middle
turbinates have been resected. A wide antrostomy
is performed down to the level of the nasal fl oor and
posteriorly to the posterior wall of the maxillary sinus. The
infraorbital nerve (ION) is in view laterally and superiorly. The
sphenopalatine artery (SPA) is exposed and ligated at the
sphenopalatine foramen.
SPA
https://t.me/med1917
Jugular Foramen Approach
ION
IMA
NP
Fig. 23.2 The sphenopalatine artery (SPA) is identifi ed and
followed and exposed proximally by removing the posterior
wall of the maxillary sinus using Kerrison rongeurs and bone
curettes. By removing the posterior wall of the maxillary sinus,
the pterygopalatine fossa (PPF) and infratemporal fossa (ITF)
are entered. The anterior compartment of the PPF contains
periosteal fascia (F), adipose (A), and branches of the internal
maxillary artery (IMA). The entire posterior wall, the underlying
fascia, fat, and the vasculature must be removed to provide a
wide exposure. NP, nasopharynx.
A
F
IMA
LPM
Fig. 23.3 Following removal of the internal maxillary artery
branches and fat, the temporalis (TM) and lateral pterygoid
(LPM) muscles can be seen. An important landmark to note
is the buccal nerve (BN) that is found running between
these two muscles. IMA, internal maxillary artery; ION,
infraorbital nerve.
TM
BN
TM
LPMs
LPMi
MPM
LPP
Fig. 23.4 The inferior head of the lateral pterygoid muscle
(LPMi) must be removed. The superior head (LPMs) is in view
here. The buccal nerve (BN) is followed proximally and is seen
running between the upper and lower heads of the lateral
pterygoid muscle. The lateral pterygoid plate (LPP) has been
partially resected to reveal the medial pterygoid muscle (MPM).
BN
SB
LPMs
MPP
BN
MPM
Fig. 23.5 The lateral pterygoid plate (LPP) has been resected
up to the skull base (SB) except for the inferior portion. The
lateral pterygoid plate serves as a landmark for the internal
carotid artery because it lies in the same sagittal plane.4 The
medial pterygoid muscle (MPM) is in view. The resection of
the lateral pterygoid plate and muscle enables the dissection
of the buccal nerve all the way back to the foramen ovale. BN,
buccal nerve; LPMi, lateral pterygoid muscle inferior head;
LPMs, lateral pterygoid muscle superior head; MPP, part of the
medial pterygoid plate that has been removed.
LPMi
LPP
241
Jugular Foramen Approach
https://t.me/med1917
Again, the BN is traced posteriorly as it will lead to
the mandibular nerve. The inferior portion of the LPP
serves as landmark for the internal carotid artery (ICA)
in the sagittal plane.
4
• The LPM is removed as much as possible. Medially, one
will see the MPM and the tensor veli palatini muscle
TVPM
MPM
a
Fig. 23.6 (a) View after further resection of the lateral pterygoid muscle (LPM). The posterior division of the mandibular nerve (V3),
which contains predominantly aff erent fi bers, is seen coming from the area of the foramen ovale. The medial pterygoid muscle (MPM)
can be seen here running from the pterygoid fossa, posteriorly, laterally, and inferiorly as it will insert on the medial surface of the
mandibular angle. Just medial to it and running perpendicularly, the tensor veli palatini muscle (TVPM) with its overlying fascia can be
seen. (b) Close-up picture of the medial pterygoid muscle and the tensor veli palatini muscle. LPP, lateral pterygoid plate.
V3
LPM
(TVPM). These two muscles are seen running almost
perpendicularly (Figs. 23.6 and 23.7).
• The TVPM is then resected and the cartilaginous
eustachian tube (ET) is then visualized posterolateral to it running in the direction of the middle ear
(Fig. 23.8).
TVPM
V3
MPM
LPP
b
242
BN
BN
TVPM
V3
TVPM
a
Fig. 23.7 (a) The tensor veli palatini muscle (TVPM) is seen here originating from the scaphoid fossa of the pterygoid process and
medial aspect of the spine. The overlying fascia has been partially removed. The buccal nerve (BN) and posterior division of the
mandibular nerve (V3) can be seen as they go toward the foramen ovale. (b) Close-up view of the same.
b
V3
• The TVPM is resected inferiorly to visualize the levator
https://t.me/med1917
veli palatini muscle (LVPM) which runs in the same direction as the ET (Fig. 23.9). The LVPM is an important
landmark as it will lead us to the PPS (Fig. 23.10).
• The mandibular nerve (V3) is lateralized and will
reveal the fatty contents of the prestyloid space within
the PPS (Fig. 23.11). Removal of the fatty contents will
reveal the stylopharyngeal muscle which separates the
pre- and poststyloid spaces. The fascial of the carotid
sheath can be seen as you dissect into the poststyloid
space (Fig. 23.11).
• The poststyloid space is dissected, revealing the cranial
nerves and the JF is seen posterior and lateral to the
ICA (Figs. 23.12 and 23.13). The cranial nerves and the
sympathetic chain run in between the ICA and the JF
(Fig. 23.14).
Jugular Foramen Approach
V3
ET
TVPM
Fig. 23.8 The tensor veli palatini muscle (TVPM) is resected
revealing the cartilaginous eustachian tube (ET). The ET runs
from the nasopharynx to the middle ear in a posterior, lateral,
and superior direction. It enters the skull base anterior to the
internal carotid artery. The mandibular nerve (V3) and its
branches are being retracted laterally.
V3
ET
LVP M
Fig. 23.9 Further removal of the tensor veli palatini muscle
inferiorly reveals the levator veli palatini muscle (LVPM). ET,
eustachian tube; V3, mandibular nerve.
FO
BN
MMA
ET
V3
LVP M
Fig. 23.10 Panoramic view of the dissection demonstrating
the structures and landmarks that can be visualized in the
parapharyngeal space. The branches of V3 can be seen. The
middle meningeal artery (MMA) is seen immediately posterior
to the foramen ovale (FO). The levator veli palatini muscle
(LVPM) can be seen.
243
Jugular Foramen Approach
https://t.me/med1917
LVP M
PPS
a
CS
c
b
d
SPM
ICA
Fig. 23.11 (a) Zoomed-out view of the parapharyngeal space (PPS) with the fatty contents of the prestyloid space in view. (b) Zoomed-
in view of the parapharyngeal space. By dissecting through the prestyloid compartment, the stylopharyngeal muscle (SPM) can be seen
which divides the prestyloid and poststyloid spaces. LVPM, levator veli palatini muscle. (c) Once the fat has been removed from the
prestyloid space, the fascia of the carotid sheath (CS) comes into view. (d) The carotid sheath is opened and the internal carotid artery
(ICA) is exposed.
244
Соседние файлы в папке Библиотека им академика М.И. Перельмана