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Venous Drainage of the Brain Presentation pptx
1. Venous Anatomy of the Brain
Dr.A.Supriya
(1st year Post Graduate –Dept of Neurosurgery)
2. Peculiarities of Veins in CNS
The cerebral veins DO NOT run together with the
arteries
They are VALVELESS,thin walls lack muscular tissue
At numerous sites the veins are most adherent to the
brain than arteries,this helps in imaging as the
displacement of veins may provide more localizing
information in neuroradiological studies
Cerebral veins may pose obstacles during surgery of
deep seated lesions and in meningioma surgeries
along the SSS
3. Cerebral venous system (Gross
Anatomy)
C. V. drainage comprises of 3 segments:-
1) Outer/Superficial segment:- drains scalp,
muscles, tendons by scalp veins
2) Intermediate segment:- draining skull, diploe,
duramater by diploic veins, emissary veins,
meningeal veins & dural venous sinuses
3) Cerebral segment:- draining brain proper by
Superficial & Deep Cortical Veins
8. Meningeal Veins
The small venous channels that drain the dura mater
covering the cerebrum are called the meningeal
veins
They are actually small sinuses that usually
accompany the meningeal arteries
Course between the arteries and the overlying bone
The meningeal veins receive diploid veins from the
calvarium.
The meningeal veins drain into the large dural
sinuses along the cranial base at their lower margin
and into the venous lacunae and superior sagittal
sinus at their upper margin
10. DURAL VENOUS SINUSES
These are venous spaces, the wall of which
are formed by dura mater,located between
meningeal and periosteal layers of duramater
Have an inner lining of endothelium, unlike other
veins,these are composed of tough fibrous tissue of
dura
Hence they exhibit greater tautness and DO NOT
collapse when injured
Receive venous blood from brain, meninges
and bones of skull.
There are 23 venous sinuses, of which 8 are
paired and 7 are unpaired.
14. Superior Sagittal Sinus
Largest of venous sinuses
Starts from Foramen caecum,grooves along the
vault of the skull, extends posteriorly , ends at the
internal occipital protruberance, where it continues
as transverse sinus,majority of the venous drainage
goes to right transverse sinus
As it runs upwards and backwards,the sinus
becomes progressively larger in size - 4mm
diameter at the frontal region whereas 10mm at
lambda
Traingular in cross section
16. SSS - Lacunae
VENOUS LACUNAE
Enlarged venous spaces, called lacunae, are contained in the dura
mater adjoining the superior sagittal sinus
• The lacunae may extend along the medial extent of the
hemisphere adjacent to the falx and as far as 3 cm lateral
over the convexity.
• Entering or occluding a lacuna at operation does not
necessarily result in occlusion of the cortical veins or the
superior sagittal sinus
because most of the veins
course deep to
the lacunae and
usually empty directly into the sinus.
17. SSS deviation
The SSS was deviated to the right side of the sagittal
suture in 54% at the bregma and 64% at the
midpoint of the sagittal suture and the lambda. The
maximal deviation was approximately 10mm to the
right side. It is usually located approximately 3.5mm
at the bregma, 4.5mm at the midpoint of the sagittal
suture, and 5.7mm at the lambda.
18. Inferior Sagittal Sinus
It is a small channel that lies in the posterior 2/3rd of
lower concave free margin of falx cerebri
Originates above the anterior portion of corpus
callosum,enlarges as it courses posteriorly to join the
Straight sinus
Arises from union of veins from the adjacent parts of
Falx,corpus callosum and cingulate gyrus
Often forms “hook” like bend with apex directed
forward
20. Inferior Sagittal Sinus
Largest tributaries are peri callosal veins
SSS may communicate through venous channels in
the falx
21. Straight Sinus
Originates behind the splenium of the corpus
callosum at the union of the inferior sagittal sinus
and the great vein
It continues posteriorly and downward in the junction
of the tentorium and falx. It may drain into either
transverse sinus, but most commonly drains
predominantly into the left transverse sinus.
23. Tranverse Sinus
Two on both sides - right and left
Originate at the torcular herophili and course
laterally from the internal occipital protuberance ,
between the attachments of the tentorium to the
inner surface of the
occipital bone
Becomes the Sigmoid sinus at the site just behind
the petrous ridge, where the transverse and superior
petrosal sinuses meet.
25. Tranverse Sinus
Right transverse sinus that is usually larger and
receives the majority of the drainage from the
superior sagittal sinus. The left transverse sinus is
usually smaller and receives predominantly the
drainage of the straight sinus.
Thus, the right transverse sinus, right sigmoid sinus,
and right jugular vein contain blood from the
superficial parts of the brain
And the left transverse sinus, left sigmoid sinus, and
left internal jugular vein contain blood mainly from
the deep parts of the brain drained by the internal
cerebral, basal, and great veins
26. Sigmoid sinus
Sigmoid sinus originates at the site just behind the
petrous ridge, where the transverse and superior
petrosal sinuses meet. Exits cranium as IJV
27. Tentorial Sinuses
These are 2 constant sinuses – but rarely
symmetrical – right and left tentorial sinuses
Right tentorial sinus – formed by convergence of
veins from superior surface of cerebellum
Left tentorial sinus – formed by lateral and iinferior
surfaces of occipital and temporal lobes
28. Cavernous sinuses
The paired cavernous sinuses are situated on each
side of the sella turcica,in middle cranial fossa and
are connected across the midline by the anterior and
posterior intercavernous sinuses
29. Cavernous sinuses
Anteriorly, each cavernous sinus communicates with
the
sphenoparietal sinus and the ophthalmic veins
Middle portion communicates through small veins
that pass through the foramina spinosum and ovale
Posteriorly, the cavernous sinus opens directly into
the basilar sinus, which sits on the clivus.
It communicates through the superior petrosal sinus
with the junction of the transverse and sigmoid
sinuses and through the inferior petrosal sinus with
the sigmoid sinus
31. Cavernous sinuses
In all communications, blood can flow in either
directions.
Can be sources of infection and thrombosis
In cases of ottitis media and mastoid abcess the
infection can pass through the superior and inferior
petrosal sinuses to the cavernous sinus via the
labyrinthine veins and the mastoid emissary veins.
Dangerous area of the face:
three points of triangle are the 2 corners of mouth
and the bridge of nose. Infections from the face can
spread in retrograde direction and cause thrombosis
of the cavernous sinus via facial vein and pterygoid
plexus.
32. Superior Petrosal Sinus
The superior petrosal sinus courses within the
attachment of the tentorium to the petrous ridge
Its medial end connects with the posterior end of the
cavernous sinus, and its lateral end joins the
junction of the transverse and sigmoid sinuses.
33. Sphenoparietal, Sphenobasal, and
Sphenopetrosal Sinuses
The sphenoparietal sinus is the largest of the meningeal
channels coursing with the meningeal arteries along the
lesser wing of sphenoid
It accompanies the anterior branch of the middle
meningeal artery above the level of the pterion.
34. Occipital Sinus
Smallest of Sinuses
Lies in the attatched
margin of Falx Cerebelli
Communicates cranially
with confluence of
sinuses , caudally with
vertebral venous plexus
Sometimes it can
deviate to one side to
join sigmoid sinus –
Oblique occipital sinus
35. CONFLUENCE OF SINUSES
Latin confluens sinuum
Torcular herophilli
Is junction of following dural venous sinuses-
SSS,Straight sinus,occipital sinus,Transverese
sinus.
36. Anastamotic Veins
The largest veins on the lateral surface are
the veins of Trolard and Labbé and the
superficial sylvian vein
37. Anastamotic Veins – Vein of Trolard
The vein of Trolard, also called the superior
anastomotic vein, is the largest anastomotic vein
crossing the
cortical surface of the frontal and parietal lobes
between the superior sagittal sinus and the sylvian
fissure
Located at a site that would correspond to the
precentral, central, or postcentral vein (most
common)
38. Anastamotic Veins - Vein of Labbé
The vein of Labbé, also called the inferior
anastomotic vein, is the largest anastomotic channel
that crosses the
temporal lobe between the sylvian fissure –usually
the midpoint of sylvian fissure to the anterior most
part of transverse sinus
39. Anastamotic Veins – Sup. Sylvian Vein
The superficial sylvian vein usually arises at the
posterior end of the sylvian fissure and courses
anteriorly and
inferiorly along the lips of the fissure
It penetrates the arachnoid covering the anterior end
of the sylvian fissure and joins the sphenoparietal
sinus
40. Cerebral venous system (Gross
Anatomy)
C. V. drainage comprises of 3 segments:-
1) Outer/Superficial segment:- drains scalp,
muscles, tendons by scalp veins
2) Intermediate segment:- draining skull, diploe,
duramater by Diploic veins, Emissary veins,
Meningeal veins & Dural venous sinuses
3) Cerebral segment:- draining brain proper by
Superficial & Deep Cortical Veins
42. Superficial Cortical veins
The superficial venous network is comprised of
vessels coursing on the cortical surface, and
collecting blood from the outer 1–2 cm of the
cerebral cortex and subcortical white matter.
This group of cortical veins terminate by exiting the
subarachnoid space to become bridging veins that
cross the subdural space and empty into the venous
sinuses
in the dura mater.
43. Bridging Veins
Divided into 4 groups based on their site of
termination:-
1. Superior sagittal group
2. Tentorial group, which drain into transverse or
lateral tentorial sinus
3. Sphenoidal group, drain into sphenoparietal or
cavernous sinus
4. Falcine group, drain into straight or inf sagittal
sinus
44. Superficial Cortical veins
Divided into 3 groups based on whether they drain the
lateral, medial, inferior surface of the hemisphere
Lateral (Frontal,temporal,parietal,occipital)
Medial (Frontal,temporal,parietal,occipital)
Inferior (Frontal,temporal,parietal,occipital)
45. Superficial Cortical veins - Frontal
Divided into groups that drain the
Lateral
Medial
Basal / Inferior surfaces of the lobe
46. Superficial Cortical veins
Frontal-Lateral
Ascending group Descending group
Drain into SSS
Frontopolar
Anterior frontal
Middle frontal
posterior frontal
Precentral
central veins.
Drain into Sylvian vein
Fronto Sylvian
60. Superficial Cortical veins - Occipital
Divided into groups that drain the
Lateral
Medial
Basal / Inferior surfaces of the lobe
61. Superficial Cortical veins - Occipital
Lateral occipital veins are directed forward rather
than backward , and enter the superior sagittal sinus
for a distance of 4 to 5 cm proximal to the torcular
herophili
Medial surface of the occipital lobe is drained by the
anterior and posterior calcarine veins
The inferior surface of the occipital lobe is drained by
the occipitobasal vein. – finally medial and inferior
surface veins darin into Basal vein
63. Cerebral venous system (Gross
Anatomy)
C. V. drainage comprises of 3 segments:-
1) Outer/Superficial segment:- drains scalp,
muscles, tendons by scalp veins
2) Intermediate segment:- draining skull, diploe,
duramater by Diploic veins, Emissary veins,
Meningeal veins & Dural venous sinuses
3) Cerebral segment:- draining brain proper by
Superficial & Deep Cortical Veins
64. Deep Cortical Veins
Drain the deep white matter,Choroid
plexus,Diencephalon,Basal Ganglia
Drain into Internal cerebral veins and Great cerebral
vein of Galen
65. Deep Cortical Veins
2 groups
1. Ventricular group
Internal Cerebral veins
1. Cisternal group
Basal veins and Great vein of Galen
68. Deep Cortical Veins –Internal Cerebral
Located near the midline in the tela
choridea of the roof of 3rd ventricle
Extend caudally from interventricular
foramina to quadrigeminal cistern
Recieves
1. Thalamo striate vein
2. Choroidal vein
3. Septal vein
4. Epithalamic vein
5. Lat.Ventricular vein
There these paired veins join with
Basal vein to form Great Cerebral
69. Deep Cortical Veins – Basal Vein
Basal vein of Rosenthal arises near medial part of
the anterior temporal lobe
Recieves blood from
1. Anterior cerebral vein
2. Deep middle cerebral vein
3. Inferior striate vein
70. Deep Cortical Veins –Great Cerebral of
Galen
Recieves drainage from
1. Paired internal cerebral veins
2. Paired basal veins
3. Paired ccipital veins
4. Posterior callosal vein
This short vein passes caudally
beneath the splenium of corpus
callosum
Empties into Straight sinus