The document summarizes the blood supply and venous drainage of the spinal cord. It discusses the following key points in 3 sentences: The anterior spinal artery runs longitudinally down the cord and provides the main blood supply. It receives blood from radiculomedullary arteries, including the artery of Adamkiewicz which is a major vessel. The venous drainage involves the anterior and posterior longitudinal veins which drain into radicular veins and eventually into the internal and external vertebral venous plexuses.

1. Blood supply of
spinal cord
Moderator : Dr. R.K.Arora
Associate prof & Head
Dept of Neurosurgery
By Dr. Raj kumar Pannem
SR, Neurosurgery,
AIIMS , Rishikesh.

2. •ARTERIAL SUPPLY
•VENOUS DRAINAGE
•CLINICAL SIGNIFICANCE

3. Anterior spinal artery
• Longitudinal artery runs down the cord
in anterior median sulcus.
• Originates from both vertebral arteries
as pair and union occurs intracranially ,
but occasionally descend several
centimetres before joining (1) .
• It is made up of series of anastomotic
networks rather than single
uninterrupted tract (2).
1.Gillilan L. 1958. The arterial blood supply of the human spinal cord. J Comp Neurol 110:75-103.
2.Infante E, Alter M. 1970. Vascular disease of the spinal cord. Minn Med 53:1009-1017.

5. • Its continuity depends on anastomotic
branches from radiculomedullary arteries (1,2).
• The diameter of artery varies from region to
region.
• Maximum : Lumbosacral : Upto 1.2mm
• Minimum : T6 to T8 or T10 : Upto 0.2mm or
less (3).
1.Suh T H, Alexander L. Vascular system of the human spinal cord . Arch eurol Psychiatry 1939;4 I :659—677
3. Gillilan L. 1958. The arterial blood supply of the human spinal cord. J Comp Neurol 110:75-103.

6. • The diameter of artery correlates with relative amount of gray matter
at given level.
• So its wider at cervical and lumbar enlargement , because of limb
innervation needs more synapses , more grey matter , more blood
supply(1).
• It is narrowest in mid thoracic region
1.Gillilan L. 1958. The arterial blood supply of the human spinal cord. J Comp Neurol 110:75-103.

8. Branches of ASA.
• Gives Sulcal (central) arteries
in the midline which
penetrates the cord substance
and supplies the cord(1).
• Cervical region : 5 to 8 .
• Thoracic region : 2 to 6 .
• lumbosacral area : 5 to 12(2).
1.Sulcal and intrinsic blood vessels of spinal cord , Arch neurpsych, 1939.
2.Netters neuroanatomy text book.

9. • Each sulcal artery contributes to the arterial supply of only one side of
spinal cord at each level(1).
• The sulcal vessel then divides , sending branches to one level above
and below to anastomose with higher and lower levels (1)
• Lumbosacral region receives the richest blood supply , followed by
cervical region(1).
1.Sulcal and intrinsic blood vessels of spinal cord , Arch neurpsych, 1939.
2.Netters neuroanatomy text book.

10. • Thoracic region has irregularity in the
alternate supply to either side and
sulcal anastomotic branches also(1).
• ASA Supplies : Anterior horn, the
lateral (intermediate) horn, the
central gray matter, and the basal
part of the posterior horn(2).
1.Sulcal and intrinsic blood vessels of spinal cord , Arch neurpsych, 1939.
2.Netters neuroanatomy text book.

13. POSTERIOR SPINAL ARTERIES
• Paired.
• Originates from vertebral
artery proximal to PICA or
PICA itself.
• Descends on the posterior
surface of cord medial to
dorsal roots (1).
1.Gillilan L. 1958. The arterial blood supply of the human spinal cord. J Comp Neurol 110:75-103.
2.Carpenters textbook of neuroanatomy.

14. • Max diameter : Lumbosacral part :0.8 mm
• Minimum diameter : T2-T6 or lower : 0.I mm(1).
• These vessels receive variable contributions from the posterior
radicular arteries(2).
• At certain sites they become so small that they appear
discontinuous(2).
1.Gillilan L. 1958. The arterial blood supply of the human spinal cord. J Comp Neurol 110:75-103.
2.Carpenters textbook of neuroanatomy.

15. • Mainly supplies the posterior
horns and posterior funiculus(1).
• POSTERIOR PIAL PLEXUS:
Together with two posterior
spinal arteries and many small
anastomosing arterioles.
• It is in fact continuation of lateral
and anterior pial plexus formed
by arteriolar branches from ASA.
Ref :Carpenter textbook of neuroanatomy.

16. • It receives tributaries from 10 to 23
posterior radiculomedullary arteries.
• Cervicothoracic region : one ,
sometimes 2 tributaries per each
segment.
• Between T4 to T8 : 2 to 3 posterior
radiculomedullary arteries.
• In thoracolumbar region there are several
feeders , one of which may be called
posterior radicular branch of artery of
Adamkiewicz.
Ref :Netters nervous system.
Ref :Carpenter textbook of neuroanatomy.

17. Conus basket(1)
• Anterior and two posterior
spinal arteries unite at lower
aspect of the conus medullaris.
1.Doppman J, Di Chiro G, Glancy D. 1969. Collateral circulation through dilated spinal cord arteries in aortic coarctation and extraspinal
arteriovenous shunts. An arteriographic study. Clin Radiol 20:192-197.

18. Radicular / Radiculomedullary arteries
• These arise from segmental arteries through out the length of spinal
cord.
• Radicular branches can be classified into three types:
1. Proper radicular branches : Ends at root level.
2. Pia mater radicular branches: Ends over the surface of cord.
3. Spinal branches / medullary branches: Supplies cord.
G Lazorthes Arterial Vascularization of the Spinal Cord. Recent Studies of the Anastomotic Substitution Pathways , J

20. Radicular/medullary arteries
• They arise from the segmental arteries.
• Size : 0.2 to 1.2 mm(1).
• Cervical region : From vertebral arteries ,
ascending cervical arteries and deep cervical
arteries.
• Thoracic region: Intercostal arteries
• Lumbar region: Lumbar arteries , iliolumbar
arteries.
• Sacral & coccygeal : Lateral sacral artery.
1.Gillilan L. 1958. The arterial blood supply of the human spinal cord. J Comp Neurol

21. • Dorsal division of segmental
artery gives branches to
corresponding vertebra and
spinal segment , which enters
through intervertebral
foramen(1).
1.Bergmann L, Alexander L. 1941. Vascular supply of the spinal ganglia. Arch Neurol Psychiatry 46:761-782

23. Image courtesy :- Pinrest.com

24. Total number of Radicular branches
• Varies from person to person.
• Total 7 or 8 really participate in vascularization of spinal cord (1).
• The anterior radicular arteries : Vary from 2 to 17, but mostly
between 6 and 10.
• The posterior radicular arteries : 10 to 23 (2)
1.G Lazorthes Arterial Vascularization of the Spinal Cord. Recent Studies of the Anastomotic Substitution Pathways , J Neurosurg,
1971.
2. Carpenter textbook of neuroanatomy.

25. • In cervical region one radicular artery arises from vertebral artery at
C3 level.
• Lower cervical segmental branches arises ascending and deep cervical
arteries and supreme intercostal artery.

26. • How ever any neck vessel in the
vicinity may give rise to segmental
artery.
• Some lower cervical segmental
branches occasionally arise directly
from subclavian artery.
• In the cervical region, the arterial
blood will reach the spinal cord via
8–10 unpaired anterior medullary
arteries that branch off the posterior
segmental arteries in the head and
neck.
Crosby E, Gillilian L. 1962. Correlative Anatomy of the Nervous System. New York: The Macmillan Company.

27. Image courtesy : Netters atlas of human
anatomy..

28. • Unlike thoracic and lumbar regions of
the spinal cord, while cervical spinal
cord segments are supplied equally
from both sides.
• Spinal branches course along the ventral
surface of the spinal root they
accompany.
• A single spinal branch may become
either an anterior or posterior radicular
artery, or divide to form both.
Ref :Carpenter textbook of neuroanatomy.

29. The artery of Adamkiewiecz
• Anterior radicular artery appreciably larger than
all others(1).
• AKA : Arteria radicularis magna
• In 75% of cases : Originates at T9 to T12 level.
• This radicular artery travels with a lower thoracic
or upper lumbar spinal root most frequently on
the left side.
• In a meta analysis (2) , present in 84.6%.
• Single in 87.4% .
• 76.6% left side , 23.4% right side.
• Originating between T8 to L1 in 89% population.
1.Carpenter textbook of neuroanatomy.
2.Ref: Dominik Taterra ,Artery of Adamkiewicz: a meta-analysis of anatomical characteristics. J.Neuroradiology , 2019.
Albert W.
Adamkiewiecz.
(1850 – 1921)

30. • The cervical spinal cord receives up to 6 anterior radicular arteries,
while the thoracic cord receives 2 to 4 and the lumbar cord has 1 or 2.
• Thoracic level , greatest length between radicular arteries, means
occlusion of one radicular artery may seriously compromise its
circulation.
• The upper thoracic (T1-T4) and first lumbar (L1) spinal segments :
Most vulnerable regions of the spinal cord.
Ref :Carpenter textbook of neuroanatomy.

31. • The blood supply may be jeopardized in certain transitional regions
where its arterial supply is derived from more than one source.
• Example, the cervical segments supplied primarily by branches of the
vertebral artery and lesser extent by small branches of the ascending
cervical artery.
• The upper segments of the thoracic cord , on the other hand, are
dependent upon the radicular branches of the intercostal arteries.
Ref :Carpenter textbook of neuroanatomy.

32. • If one or more of the parent intercostal vessels are compromised by
injury or ligature, spinal cord segments T1 to T4 could not be
adequately maintained by the small sulcal branches of the anterior
spinal artery
Ref :Carpenter textbook of neuroanatomy.

33. Image courtesy : Netters atlas of human
anatomy..

34. • Occlusion of one intercostal artery in a vulnerable region can result in
a spinal cord infarction.
• It clinically presents as transection of cord.
• This clinical picture is seen with dissecting aneurysms of the aorta or
as a result of surgery on the aorta where more than one intercostal
artery may be occluded.
Ref :Carpenter textbook of neuroanatomy.

35. Arterial vasacorona
• It is the communication between
anterior and posterior spinal
arteries.
• It spreads horizontally in sub pial
region.
• Supplies peripheral portion of
lateral funiculi.
Ref :Carpenter textbook of neuroanatomy.

36. Venous drainage

37. Anterior longitudinal venous trunk
• General distribution similar to
that of spinal arteries.
• Anterior longitudinal venous
trunks consist of anteromedian
and anterolateral veins.
• Anterolateral regions of the
spinal cord drain into antero
lateral veins and into the venous
vasacorana.
Ref :Carpenter textbook of neuroanatomy.

38. • Anteriomedian vein :-
• It lies posterior to ASA in midline
sulcus.
• Sulcal veins drain into this vein.
• Unlike sulcal artery , sulcal vein has
two tributaries which drain from
both sides of spinal cord at each
level.
• Sulcal veins maintains a
perpendicular course unlike arteries.
Ref :Carpenter textbook of neuroanatomy.
Image courtesy : Pinrest.com

39. • The anteriomedian and
anteriolateral veins are drained by 6
to 11 anterior radicular veins.
• These are distributed along the
spinal cord.
• Among them , the largest radicular
vein present in lumbar region ,
called vena radicularis magna.
Ref :Carpenter textbook of neuroanatomy. Image courtesy : Pinrest.com

40. Posterior longitudinal venous trunks
• Consisting of a posteromedian vein
and paired posterolateral veins.
• Drain the posterior funiculus, the
posterior horns (including their basal
regions), and the white matter in the
lateral funiculi adjacent to the
posterior horn.
Ref :Netters nervous system.

41. • The longitudinal veins are connected with each other by coronal veins
(venous vasocorona) that encircle the spinal cord.
• Vasa corona drains rest of the spinal cord via radial veins.
Ref :Netters nervous system.

42. • These anterior , posterior spinal
veins along with vasa corona (
lateral pial veins) drain into
anterior and posterior
medullary veins ( radicular
veins).
• They travel along with nerve
roots and medullary arteries.
• The medullary veins unite with
radicular veins and with
branches from the anterior and
posterior internal vertebral
venous plexuses to form the
intervertebral veins.
Ref :Netters nervous system.

43. Internal vertebral venous plexus
• Networks of veins lying in
the epidural space within
the vertebral canal.
• Anterior and posterior
groups, interconnected by
many smaller oblique and
transverse channels.
• The anterior internal plexus
consists of longitudinal
veins lying on the posterior
surfaces of the vertebral
bodies.
Ref :Netters nervous system.

44. • Posterior internal plexus are smaller
than their anterior counterparts.
• They are located on each side of the
median plane in front of the vertebral
arches and ligamenta flava.
• They anastomose with the veins of
the posterior external vertebral plexus
via small veins that pierce the
ligaments and pass between them.
Ref :Netters nervous system.

45. • At each intervertebral space there are connections with thoracic,
abdominal, and intercostal veins, as well as with the external
vertebral venous plexus.
• No valves , so blood may pass directly into the systemic venous
system.
• When intra abdominal pressure is increased, venous blood from the
pelvic plexus passes upward in the internal vertebral venous system.
• When the jugular veins are obstructed, blood leaves the skull via this
plexus.
• Continuity of this venous plexus with the prostatic plexus leads to
metastasis.
Ref :Carpenter textbook of neuroanatomy.

46. External vertebral venous plexus
• Consists of anterior and posterior
parts, which anastomose freely.
• Anterior external plexus :- Lie in
front of the vertebral bodies.
• Drains vertebral body.
• Communicate with internal plexus
through basivertebral veins.
Ref :Netters nervous system.

47. • Posterior external plexus:-
Located over the vertebral
laminae and extending around
the spinous, transverse, and
articular processes.
• In upper cervical region :
communicates with the occipital
veins .
• Also communicates with the
vertebral and deep cervical
veins.
• And a few channels pass through
the foramen magnum to the
dural sinuses in the posterior
cranial fossa.
Ref :Netters nervous system.

48. Basivertebral veins
• Resemble the cranial diploe, and
travel through the cancellous tissue
of the vertebral bodies.
• They converge to form a
comparatively large, single
(occasionally, double) vein that
emerges through the posterior
surface of the vertebral body.
• They end, via openings guarded by
valves, into the anterior internal
vertebral plexus.
• Also drain into anterior external
plexus.
Ref :Netters nervous system.

49. The intervertebral veins
• Drain most of the blood from the spinal cord and from the internal
and external vertebral venous plexuses.
• They accompany the spinal nerves through the intervertebral
foramina and end in
• The vertebral veins :- Cervical region.
• Posterior intercostal and subcostal veins : Thoracic region.
• Lumbar veins : Lumbar region.
• Lateral sacral veins : Sacral and coccygeal region.
Ref :Netters nervous system.

50. CLINICAL SIGNIFICANCE
•Arteriovenous malformations
•Spinal cord infraction

51. Arteriovenous malformations
SPETZLER CLASSIFICATION SYSTEM :
(1) Extradural AVFs
(2) Intradural dorsal AVFs
(3) Intradural ventral AVFs
(4) Extradural-intradural AVMs
(5) Intramedullary AVMs
(6) Conus medullaris AVMs
Ref : Youmans and winn neurological surgery.

52. Extradural AVFs
• Between the epidural segment of a radicular artery,
before it dives into the dural sleeve of a nerve root, and
the epidural venous plexus.
• Extensive network of veins in the epidural space.
• Compression on the thecal sac and nearby nerve roots.
• Blood supply shunted away from the spinal cord and
contributing to myelopathic symptoms.
Ref : Youmans and winn neurological surgery.

53. Intradural dorsal AVFs
• Between radicular artery, after entering the dural sleeve of the nerve
root and a medullary or radicular vein.
• Venous hypertension and vascular engorgement create a local mass
effect.
• Venous congestion causes myelopathy.
• Acute haemorrhage : Acute myelopathy.
Ref : Youmans and winn neurological surgery.

54. Intradural ventral AVFs
• Anterior spinal artery and a midline venous plexus.
• 3 types , A , B , C.
• Type A: Small , simple , feeder from ASA.
• Type B: Large , Primary feeder ASA , but multiple small feeders
from adjacent arteries.
• Type c: Giant fistulas with multiple arterial pedicles and
immensely engorged venous outflow channels.
• High-flow shunts with striking vascular steal from spinal cord
tissue, which causes overt myelopathy and spinal cord ischemia.
Ref : Youmans and winn neurological surgery.

55. Extradural-Intradural AVMs
• Extensive AVMs that can encompass an entire somite of the spine and
involve bone, muscle, skin, and nerve tissue.
• Site : Intra and extra dural ,may extend beyond spine.
• Through mass effect, venous congestion , and arterial steal
phenomenon, they lead to progressive myelopathy and neurological
deficit.
Ref : Youmans and winn neurological surgery.

56. Intramedullary AVMS
• True AVMs of cord parenchyma.
• Feeding arteries : Either the ASA or PSA.
• Intervening nidus
• Drainage : Coronal venous plexus.
• Symptoms due to acute hemorrhage or steal phenomenon or
progressive myelopathy due to compression.
Ref : Youmans and winn neurological surgery.

57. Conus medullaris AVMs
• Multiple feeders from both the ASA and PSA.
• Large space in the area : Large , dilated venous ectasia.
• Mass effect on the region and result in myelopathy.
• Venous congestion
• Arterial steal on the conus
• Cauda equine–type syndrome as a result of compression on nerve
roots as they exit the conus.
Ref : Youmans and winn neurological surgery.

58. Arterial spinal cord infraction
• Accounts for 1 – 2% of all strokes.
• Most of them due to ASA involvement.
• Watershed zones , i.e. T1 to T4 and L1.
• Abrupt onset of neurologic deficits, often associated with radicular or
“girdle” pain.
• Motor loss below the level of lesion with in minutes to hours.
Ref : Brazis localization in clinical neurology. Picture courtesy : Netters nervous system
textbook.

60. • Thermoanesthesia and analgesia below the level of the lesion
(bilateral compromise of spinothalamic tracts).
• Position sense, vibration, and light touch remain intact.
•PSA infract : Loss of proprioception and vibration sense below
the level of the lesion
Ref : Brazis localization in clinical neurology.
Picture courtesy : Netters nervous system

61. Picture: Netters nervous system
textbook.

62. Ref : Brazis localization in clinical neurology.

63. Venous infract
• Due to impaired blood drainage associated with dural AVFs or
hypercoagulable states.
• Since the spinal veins lack valves there is a potential for retrograde
embolization of thrombi associated with a variety of infectious
abdominal disorders, embolism, or rarely of foreign materials (e.g.,
sclerotherapy for esophageal varices ).
Ref : Brazis localization in clinical neurology.

64. Thank you