The document discusses a clinical case of a 41-year-old woman with a left-sided 4.5mm pcom aneurysm that was initially treated with endovascular flow diversion and later required surgical clipping due to persistent filling and complications including retinal artery occlusion. It emphasizes important considerations in surgical treatment after failed flow diversion, including anatomical factors and risks associated with aneurysm rupture. A search strategy using multiple databases was outlined to gather evidence-based research on this topic.

1. Evidence Based Neurosurgery
Ursalan Khan
16/10/2024
Clipping of a Previously Flow
Diverted PCOM Aneurysm:
Evidence Based Surgery and
Surgical Nuances

2. Clinical case
A 41 year old woman who works as a university lecturer was investigated for
headache and was found to have an incidental finding of a left sided 4.5mm PCOM
aneurysm. She has no significant past medical history and is a non-smoker. Her
family history is specific for her mother being treated for an unruptured intracranial
aneurysm at the age of 50. Her grandmother suffered an intracerebral haemorrhage
of unknown aetiology. She has expressed wishes to start a family.
The aneurysm was treated at a different department after discussion at their
cerebrovascular multidisciplinary team meeting with an endovascular pipeline shield
flow diverting stent deployed to the distal ICA. Her post procedural course was
complicated by a left retinal artery occlusion causing an inferior scotoma requiring a
prolonged course of dual antiplatelets. In addition, she developed symptoms of
amaurosis fugax and required re-commencement of Aspirin. On close follow up, by 3
years and 7 months the aneurysm demonstrated persistent filling via the PCOM
artery.

4. Searchable question
Surgical treatment after failed flow diversion.
Important considerations including proximal control, placement of clip and risk
of tearing the dome or the parent vessel.
Anatomical and flow factors that predispose to flow diversion failure.
Side points beyond the scope of this discussion and analysis – risk of
aneurysm
rupture following failure of flow diversion.
Risk of aneurysm rupture during pregnancy.

5. PICO Framework
Patient/Population Intervention Comparison Outcomes
Who is your patient?
Failed flow diverted
aneurysm.
What do you plan on
doing for the
patient?
Clipping.
What alternative are
you considering?
Nil at present.
What do wish to
accomplish?
Treatment of the
aneurysm.

6. Search strategy
Use 3 different databases
Medline, Embase and Scopus
Use of key words
Words that describe an article chosen by the author.
Words that come up on titles and abstracts (information available to the
database)
Use of subject headings
These are assigned descriptors to research articles by indexers of a database.
Eg medline calls these MeSH terms. Interesting fact – before 2022, 200
members
of staff were expected to index 1 million studies per year. Now automated.

7. Search strategy
Use 3 different databases
Medline, Embase and Scopus
Use of key words
Words that describe an article chosen by the author.
Words that come up on titles and abstracts (information available to the
database)
Use of subject headings
These are assigned descriptors to research articles by indexers of a database.
Eg medline calls these MeSH terms. Interesting fact – before 2022, 200
members
of staff were expected to index 1 million studies per year. Now automated.

9. 9
OFFICE I FACULTY I DEPARTMENT

10. 10
OFFICE I FACULTY I DEPARTMENT

11. 11
OFFICE I FACULTY I DEPARTMENT

13. Summary of key papers
Results Table
Study Number of Patients Aneurysm
Gressot et al 1Opthalmic artery Aneurysm
Mbabuike et al 12PCOMM
PCOMM
PCOMM
Communicating segment
Ventral ICA
Ophthalmic
Ophthalmic
Ophthalmic
Supraclinoid ICA
Posterior Cerebral
Vertebrobasilar
Fusiform basilar trunk
Kalani et al 1PICA
Nakamura et al 1CCA
Nguyen et al 1SCA
Van Der Veken et al 1MCA
17

14. Conclusions &
recommendations
for patient
Most of the reported failed flow diverted aneurysms are ophthalmic and PCOM.
None of the failed flow diverted aneurysms required proximal control.
All patients had no complications post op.
Reporter bias.