blister aneurysms

Vipul GuptaNeurointerventional SurgeryArtemis Agrim Institute of Neurosciences

Small Blister/dissecting…

“Very small, friable, symptomatic” Blister aneurysms (BA) are rare lesions characterized by a

hemispherical shape and fragile walls Non-branching sites from the dorsomedial wall of the

internal carotid artery (ICA), anterior communicating (AComA) and basilar artery …

Small size & atypical location- RA & 3D needed Blister/disecting- rapid change in size and morphology in

follow-up angiograms

Owaga A et al , Neurosurgery 2000;47:578

Meling TR et al J Neurosurg 2008;108:662

Sim SY et al J Neurosurg 2006;105:400

Management…

Imperative to suspect the blister/dissecting aneurysm planning surgical and endovascular procedures.

Pathology - focal wall defects covered by a thin layer of fibrous tissue and adventitia and lack of usual collagenous layer

High risk of premature rupture during surgery, large lacerations

Endovascular- difficult to coil, friable, continued growth, stent needed (issues in SAH)

Shikawa T, Neurosurgery 1997;40:403 Lee BH et al J Neurosurg 2008

Blister aneurysms …

Classical ICA blister aneurysms Dissecting aneurysm with a bleb Very small berry aneurysms

Issue- blister; control- protamine, coils

Evolution of endovascular mgt… Weak nature of BA and small size of the aneurysms with a

broad neck renders endovascular treatment technically challenging

A stent placement is essential in most cases so as to retain the coils within the aneurysm sac.

Attempt to pack the aneurysm with coils may result in intra-operative rupture and loose packing is likely to result in continued growth of aneurysm

Overlapping stents- may be preferable Aneurysm recurrence/growth can happen- early follow-up,

further treatment

Small Blister/dissecting…

Stents

Flow modification Intimal growth and healing Change of angles

Issues Persistent fillingAnti-platelet therapy in SAHSingle/double/flow divertor

Stent…. Flow diversion Intimal growth- healing Angle of the artery

Stent …

Classical blister aneurysm

34-year M, SAH

2 overlapping stents

1-year follow-up

Single stent

3-month follow-up

43-year M, SAH

Follow up after 6 months

Recurrence , PVO

Our experience…NO. OF PATIENTSMALEFEMALE

14 9 5

MEAN AGE 49.7 YEARS

PRESENTATIONSAHISCHEMIC STROKE

131

NO OF STENTSONE STENTTWO OVERLAPPING STENTS

11 3

LOCATIONACAPARACLINOIDALSUPRACLINOIDALICA BIFURCATIONVERTEBRAL ARTERY-PICABASILAR ARTERYPCA

2711111

COMPLICATIONTHROMBOEMBOLISM, dissection BLEEDING (extracranial – 1)

4, 1Repeat SAH- None

FOLLOW UP- ANGIOGRAMCOMPLETE OCCLUSIONALMOST COMPLETEPATIAL OCCLUSIONNO OCCLUSION-UNCHANGEDNOT AVAILABLE

5 (3-month- 2-year)3 (3-6 months)3 (3-6 month)2 (3-month F/U)1 (< 3-month)

Surgical Options….. Direct clipping, clipping plus wrapping, wrapping alone,

clipping with Sundt encircling graft clips, encircling silicone clip application, primary suturing of ICA, vascular staple clip closure of ICA and trapping with or without extracranial-intracranial bypass

Exposure of cervical ICA for proximal control before aneurysm dissection, gentle subpial dissection, complete trapping of the aneurysm before clipping and good brain protection, STA preparation

As far as possible trapping of the aneurysm should be avoided in acute phase of subarachnoid hemorrhage (oblique clipping)

Small Blister/dissecting…

Further evolution – flow diverters (stents)

0

1

2

3

4

5

6

7

8

9

10

0 10 20 30 40 50 60 70 80 90 100

Flow index

Ineffective

(clotting) Ineffective

(free flow)

Effective flow

diversion and side

branch patency

DSA – Blister aneurysm of left ICA

Antiplatelet protocol:

Ecosprin 150 mgPrasugrel 50 mg

2 hrs prior to stent deployment

Heparin 3000 IU at start of procedure1000 IU to 2000 IU prior to stent deploymentACT 300 (x 2 upper limit of normal)

A 63-year-old female patient presented with Fisher grade 2 subarachnoid hemorrhage.

D E F

B CA B

B

C D

A

U. Sarkar

21/12/15

24/12/15

Pasugrel seems to be safe and effective

Timing: 2 hours (maximal antiplatelet activity starts at 2 hours)

Low risk of thromboembolism

Our series – 11 patients

- No thromboembolism or bleeding-None needed EVD-mRS – 0, 1 – 10/11

-Not suitable in patients with history of ischemic stroke and age > 75

Key learning points

17 patients: SS, ODS, SS+Coil 1 rebleed (died)Good outcome on f/u – 82%Mortality – 18%

Blister Aneurysm

Our experience with FD vs non FD

Complete occlusion – 89% vs 71% i.f.o FD

Repeat treatment – none vs 11.7% i.f.o FD

Rebleed resulting in death – none vs 5.8% i.f.o FD

Submitted for publication

Learning points

• FD was safe and effective in these aneurysms and compared favorably with our previously reported results with stent(single/overlapping) and coiling

• In our series loading with Pasugrel and ecospirin was safe and effective for flow diverter placement in acutely ruptured blister aneurysms

• Timing is critical, we loaded two hours before the procedure

Blister aneurysms …

Blister aneurysm on other arteries Many may be dissecting in nature Role of FD may not be so well established

Dissecting blister aneurysm – poor gradeEVD

2-overlapping Enterprise stents

6-months follow-up

Had repeated nasal & gastric bleedings (Varices, Cirrhosis) - Anti-platelets were reducedAlmost completer recovery except partial vision loss due to vitreous hemorrhages

54-year F, SAH

Single stent

1-year follow-up

34-year M, TIAs (Ischemia with aneurysm)

A B C

D E F

Very small berry aneurysms

53 year manSAH H&H grade 2

Small blister/dissecting

Small blister/dissecting- important to detect and recognize Difficult cases for surgery or endovascular Previous Options- single stent, overlapping stents, stent and

coil Current TOC in ICA – FD Careful anti-platelet protocol Distinguish between blister vs dissecting vs very small berry

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