aneursym and techinques of clip application

1. TECHINIQUES OF
CLIPPING IN
ANEURYSM &
ENDOVASCULAR
OPTION
DR. AJAY KUMAR SINGH
DNB Resident
Neurosurgery
VPIMS

2. HISTORY
• 1911 : Harvey cushing; malleable vascular clip.
• 1937: Dandy; ‘V’ shaped silver clip to ICA aneurysm.
• 1950: Schwartz; cross action/ legged. (Temporary)
• Mayfield: Similar clip as Permanent
• McFadden: coated with silicon rubber
• Drake: ring or fenestrated clip
• Loughed-Kerr: spring action clip
• Olivecrona: added flanges to the clip so that it can be opened
in case of improper application.

3. TYPES OF CLIPS
There are four major clip designs
• The McFadden
• Sundt Slim-Line
• Sugita
• Yasargil
• Of these, the last two are commonly available.

5. • The mechanism of clip
opening and closure is the
basis for dividing clips
into
• Cushing: U/V type
• Scoville: Mobile fulcrum
• Heifetz and Lougheed-
Kerr: Pivot
• Yasargil and Sugita:
Alpha

6. Types of clips
• Temporary clips
• Permanent clips
– Plane
– Fenestrated clips (reduces dissection)
(Wide neck aneurysm, calcified, atherosclerotic)
• Clip Graft

7. • Temporary clips have weaker closing force than
permanent ones to minimize the risk of permanent
damage to vessels wall.
• In both, the closing force follows a hyperbolic curve
with the weakest at tips and strongest at the base of
blades.

8. Clip graft
• A vessel encircling clip,
designed to repair large
defect in the wall of vessels.
• Consist of a metallic spring
enclosing a Teflon or
Dacron graft.
• Applies pressure on the
synthetic graft, so sealing
and repairing defect

9. PARTS OF CLIPS
Three parts
• A spring with a cross action, that permits to open or close
the clip blades when it is compressed and released, respt.
• A ring, an engagement necessary to accept the applier tip
for opening and closing the clip blades.
• A pair of blade to clip the aneurysm.
Straight, curved, angled, bayonetted, sideward, hooked and
fenestrated configuration.

11. • The pivot clip resembles a clothes peg with a central
pivot and an external spring mechanism to allow for
opening.
• Scoville clip: No external springs, but were designed to
open and close based on the elastic properties of the
metal and the shape of the clip itself.

13. Material in Aneurysm Clips
• The earliear aneurysm clips: biologically inert, eg; silver.
• Tissue reaction and a tendency to corrode in vivo.
• Drake and Yasargil; Stainless steel alloys such as 301 SS.
• MR compatible clips, leading to the use of special alloys
such as MP 35 N (Sundt Slim-Line), cobalt alloys like
Phynox (Yasargil FE) or Eligiloy (Sugita Standard).
• In current practice, both Yasargil and Sugita clips are made
of medical grade titanium.

14. Main principle of clipping
• Adequate closing force
• Delicate application
• Presence of neural and vascular structure.
• Shape size, length of clips.
• Unless dome remodelling is used, the blade of a single
occluding clip be 1.5 times the width of the base.

15. Clip application technique

16. • Applying a permanent clip on an aneurysm neck is like
landing an airplane, requiring just the right “yaw,
pitch, and roll”
• Pitch refers to the slope of the clip appliers
• Yaw refers to the side-to-side rotation of the clip
appliers about a vertical axis
• Roll refers to the side-to-side rotation of the clip
appliers about the instrument’s axis.

17. • Clip appliers obstruct an
established line of sight if they
enter the surgical corridor along
or near the line of sight.
• A 15- to 30-degree difference
between the appliers line and the
sight line is needed to visualize
the blades on the aneurysm neck

18. Direction of the Clip
Rhoton’s rules of aneurysm formation
1) Arise at the branching sites on the parent artery, which
may be side branch or bifurcation.
2) Arise at turns or curves in the outer wall of the artery
where hemodynamic stress is the greatest.
3) Aneurysms point in the direction that blood would have
gone if the curve at the aneurysm site was not present
4) Each aneurysm is associated with a set of perforating
arteries that needs to be preserved.

19. 1) Perpendicular to the afferent artery and parallel to the
efferent branches with bifurcation aneurysm.

20. 2 & 3) parallel to the parent artery with aneurysms at
curves.

21. 4) parallel to the line of perforators across an
aneurysm base.

22. Types of clipping
• Simple
• Fenestrated
• Multiple
– Booster
– Tandem
– Tentative
• Clip reconstruction technique

23. Simple Clipping
This clipping strategy is
preferred for smaller
aneurysms with simple
and well-defined narrow
necks.

24. Fenestrated clip ligation technique
• Circular opening at the heel of the clip blades through
which the parent or perforating arteries may save.
• Indications :
1. To avoid an afferent or efferent artery, including
perforating vessels
2. Tandem clipping to close the distal neck of the aneurysm
not handled by the first clip
3. Reconstruction of the lumen of the parent vessel.

25. • The clip must be slightly angled
anteriorly in the axial plane to
cover the stretch of the
aneurysm neck on the A2 and
ACoA (left image).
• If the aneurysm neck is entirely
based on the ACoA (rare,) both
A1s are usually dominant and
the clip application is more
straightforward, parallel to the
ACoA (right image).

26. Multiple clips
• Allow more flexible reconstruction of regional
vasculatures lumen while effectively excluding
aneurysm neck.
• Intersecting
• Overstacking
• Understacking

27. Multiple clipping with
intersecting clips uses a
second clip angled into an
initial clip, with its tips
intersecting the blade or heel
of the initial clip at an acute,
right, or obtuse angle.

28. • Stacked clips are applied
parallel to each other.
• The initial clip typically closes
most of the aneurysm, and tips
of subsequent clips precisely
contour the remnant beneath
the initial clip (understacking).
• When above it will called as
(overstacking).

29. • An overlapping fenestrated
clip can be applied over an
initial straight clip at various
angles to close a distal neck
remnant beneath the initial clip.
• Encircles the initial clip blade,
bringing the heel of the
fenestrated clip blade against
the straight clip blade.

31. Booster clip
• To reinforce a previously placed
clip.
• May be applied perpendicular to the
previous clip or parallel.
• In rare cases, the booster clip is
applied so that its blades encompass
the blades of the previously applied
clip, ensuring its tight closure.

32. Tentative clip
• Tentative clipping pertains to placement of an initial clip
to gather or deflate the large dome and allow more
visualization around the neck.
• This clip is then repositioned or replaced after the neck
morphology is better understood.

33. Tandem Clipping
• Drake uses a straight fenestrated clip to first close the
distal aneurysm neck, and then shorter, simple clips to
close the proximal neck encircled by the fenestration.
• Wide neck aneurysm necks because the closing force of
fenestrated clips is maintained distally near their tips.
• The shorter clips used to close the fenestration contour the
reconstruction of the near neck and preserve efferent
arteries there.

34. Tandem clipping with an understacked clip closes the
aneurysm neck below the fenestration.

35. Tandem clipping with an overstacked clip closes the aneurysm
neck above the fenestration.

36. Tandem Angled Fenestrated Clipping
• Developed by Sugita that uses multiple angled fenestrated
clips applied sequentially across a broad neck projecting
away from the neurosurgeon.
• It uses 90-degree angled clips with large fenestrations and
blades of varying lengths, curves, and deviations.
• The clips are aligned with the blade tips in the same
direction, and applied toe to heel, progressing from deep
neck to near neck.

38. • Tandem counter clipping techniques align the blade tips
in opposite directions, and can be applied toe to toe
(facing) or heel to heel (cross-wise).
• Tandem angled fenestrated clips should overlap at their
interface with the adjacent clip; clips that simply meet at
their interface may permit the aneurysm to refill at these
points.

39. Fenestration Tubes
• Straight fenestrated clips can be stacked to close an
aneurysm neck and create a tube that reconstructs an
efferent artery.
Three configurations named for the direction of blood flow in
the tube.
• Anterograde
• Retrograde
• The part of the occluded aneurysm in the tube (dome).

40. • An anterograde fenestration tube builds an open tube
oriented perpendicular to the blades and transmits blood
flow through the tube anterograde to the efferent artery.

41. • A retrograde fenestration tube builds a closed tube that
turns around its blood flow and redirects it to an efferent
artery coursing from the aneurysm’s base.

42. • A dome fenestration tube does not transmit an efferent
artery and instead fenestrates the aneurysm dome.

44. Clip recontruction

45. Inspection after clipping
Inspect the aneurysm for
• Continued filling
• The efferent
• Afferent
• Perforating vasculature for patency
• The surgical blind spots.

46. ENDOVASCULAR OPTIONS

47. HISTORY
• Luessenhop and Velasquez tried to occlude a
supraclinoid ICA aneurysm by advancing a silicon
balloon into it.
• In 1973, Serbinenko expanded Luessenhop and
Velasquez’s concept and selectively obliterated an
aneurysm using detachable balloons.

48. • Mullan: electrothrombosis.
• Sheptak: isobytyl-2-cyanoacrylate into the fundus
• Dowd, Arnaud, & Higashida 1990: platinum coils.
• Guido Guglielmi 1991: electrolytically detachable coils.
• The first stent was the Neuroform stent (Boston Scientific
Target, Fremont, CA) approved by the FDA in 2007 for the
treatment of wide-necked intracranial aneurysms.

49. • Traditionally, a major disadvantage of coil embolization
is the difficulty in treating complex and wide necked
aneurysms and failure to obliterate aneurysms
completely.
• This issue triggered three major advancements.
1) The introduction of three dimensional coils.
2) Development of balloon-assisted coil embolization.
3) Introduction of neck-bridging devices and flow-
diverting stents.

50. OPTIONS
• Implantable balloons
• Embolization coils
• Bioactive embolization coils
• Adjunctive intracranial stents for use with embolization coils
• Stent-like devices.
• Flow diversion stents
Occluding the aneurysm sac (endosaccular occlusion) to those
designed to achieve a durable physiological reconstruction of the
parent vessel that gives rise to the aneurysm (parent vessel
reconstruction).

51. ANEURYSM TREATMENT
The Past
• Implantable latex balloons: occlusion or deconstruction
of the parent vessel and aneurysm,
• Further development of balloon and catheter technology
allowed for the placement of detachable silicone or latex
balloons directly into cerebral aneurysms, allowing a
constructive occlusion of the aneurysm with preservation
of the parent vessel.

52. The Present
• Detachable coils: Detachable platinum coils.
• These flexible, soft, detachable coils could be delivered
through a microcatheter.
• Atraumatic, controllable, and safer than the manipulation,
insufflation, and detachment of the predicate silicone
balloons.

54. Balloon Remodeling
• 1990s for wide-necked aneurysms.
• A temporary occlusion balloon is inflated across the neck of the
aneurysm while embolization coils are introduced.
• The balloon functions to prevent the prolapse of coils into the
parent vessel.
• After the introduction of a coil under balloon protection, the
occlusion balloon is traditionally deflated, and the coil is
observed for prolapse into the parent vessel.
• If the coil appears stable, it is detached, and the balloon is
reinflated for the introduction of the next coil.

57. Intracranial Stenting
• Higashida et al used a balloon-mounted coronary stent to
treat a wide-necked, fusiform, basilar artery aneurysm.
• The rigidity of the commercially available balloon
mounted coronary stents often precluded their delivery
and deployment within the tortuous cerebrovascular
circulation.

58. THE FUTURE
Parent Vessel Reconstruction:
• The diseased parent artery that gives rise to the saccular or
fusiform aneurysmal outpouching is primarily
reconstructed, by implantation of stents or stent-like
devices within the parent artery.
• Self-expanding intracranial microstents
• Pipeline Embolization Device.

59. Flow diversion stents
• To divert flow away from the aneurysm by placing a mesh
structure, similar to a stent, on the aneurysm neck along the
parent artery.
• It create blood stasis to allow for thrombus formation inside
the aneurysm.
• Giant or fusiform aneurysms.

60. Complication rate of 38%,
including parent artery
stenosis, distal embolism, in-
device thrombosis, branch
occlusion, and hemorrhage or
mass effects.

62. Indications
-Cerebral aneurysms: ruptured and unruptured
-Parent vessel sparing and parent vessel occlusion.
-Indications for parent vessel sparing in cases of ruptured cerebral
aneurysms
• Narrow neck diameter. (<5mm)
• Poor surgical candidacy due to medical risk factors
• Poor clinical grade
• High risk for surgical clipping due to location or size, failed attempt at
surgical clipping
• Significant vasospasm in vascular distribution removed from
aneurysm location.

63. Indications
• For parent vessel sparing in cases of unruptured cerebral
aneurysms
• Include poor surgical candidacy due to medical risk factors
• High risk for surgical clipping due to location or size,
• Failed attempt at surgical clipping
• Multiple aneurysms require more than one open surgery,
• Multiple craniotomies that might be treated by a
combination of Guglielmi detachable coils
• Open surgery to decrease the number of craniotomies.

64. Indications
• For parent vessel occlusion in cases of ruptured or
unruptured
• Fusiform aneurysm,
• Pseudoaneurysm secondary to trauma, infection, neoplasm,
or spontaneous dissection
• Large or giant aneurysms

66. THANK YOU