Acute FDS twisting and its management

PATIENT 

• 82 year-old female 
• Hystory: arterial hypertension, coronary hearth disease, DM on OAD, hypothyreosis, hypercoagulation state, other metabolical, surgical and orthopedic diagnoses (polymorbid patient)
• Symptoms:
    Sudden onset head pain in occipital region
    Sudden onset bilateral tinnitus
• Physical examination : consciouss, without lateralisation, without speech disturbance, significant neck stiffness present
• In initial work-up native brain CT was obtained

CT FINDING 

• Diffuse bilateral subarachnoidal bleeding in F-T region (with predominant location in insular region), also spreading to the prepontine, interpeduncular and cerebello-pontine cistern
• Without loss of grey-white matter differentiation
• Without hydrocephalus
• Without midline shift
• No signs of intraparenchymal hemorrhage

CTA 02.12.2021

CT ANGIO IN AXIAL PLANE 

FINDING

• Two aneurysms:
  1.Bifurcation of right MCA
  2.Right ICA (level of PCom)
• Acoording to localisation of SAH it is impossible to differentiate which one is responsible for bleeding.
• Size of aneurysms:
  1.Right MCA = 2,5mm2.Righr ICA = 4mm

INDICATION FOR DSA

• Active and symptomatic, disabling SAH bleeding on CT
• Two aneurysms of right carotid part of the Willis circle suspected on CTA

DSA MEASUREMENTS 

DSA OBLIQUE PROJECTION

DSA FINDING AND EV TREATMENT PLANNING

• DSA confirmed presence of two saccular aneurysms, one located at the level of PCom origin (right ICA) and the second one located at the level of right MCA bifurcation
• Because of the hemorrhage location, it was not clear which one was responsible for bleeding
• The decision was to treat both aneurysms with placing FDS
• Both aneurysms were planned to be treated in one seat in disto-proximal order (1. MCA an. and 2. ICA an.)

1. RIGHT MCA ANEURYSM TREATMENT

EV setup :

1. 6F Avanti short sheath
2. Benchmark delivery catether
3. Rebar-18
4. Traxscess GW
5. FDS: p48-MW-HPC-300-9

Treatment :

• Standard FD stent placement to dominant (in this case lower) branch of MCA
• FDS placement without complication
• Satisfiing position and apposition

2. RIGHT ICA ANEURYSM TREATMENT

EV setup :

1. 6F Avanti short sheath
2. Benchmark delivery catether
3. Rebar-18
4. Traxscess GW
5. FDS: p64-MW-HPC-450-15

Treatment :

• Standard FD stent placement with distal landing zone under the ICA biffurcation
• After stent deployment we observed atypical shape of stent 
• At that time, twisting of FDS was suspected

DE-TWISTING OF FDS

EV Setup :

• 6F Avanti short sheath
• Benchmark delivery catheter
• SCEPTER remodeling balloon
• Transcend GW

Approach :

• When spotting displaced and twisted FDS, intraluminal position was secured with
  pushing XT-27 microcatheter over the pusher to the M1 segment of right MCA
• Exchange of guidewire for Transcend
• Over Transcend GW placed SCEPTER remodeling balloon into the lumen of twisted FDS
• Repeated insufflation of SCEPTER with little effect on twisting
• After two attempts of PTA with SCEPTER was performed maneuver, where insufflated balloon was gently pulled away (proximally) thru FDS with definite detwisting (effect as demonstrated on video)

RESULT 

NEXT MANAGEMENT 

• Patient clinical and neurological state gradually improved
• After 5 days was transferred to local neurological department walking, with improvement of headache, diminution of bilateral tinnitus and neck stiffness
• Control MR + MRA is planned for June 2022

DISCUSSION

• Twisting: Incidence and Risk Factors of an Intraprocedural Challenge Associated With Pipeline Flow Diversion of Cerebral Aneurysms; Bender, Matthew T MD; et al. /Neurosurgery/, January 2021 - Volume 88 - Issue 1 - p 25-35. doi: 10.1093/neuros/nyaa309
• Torsional Characterization of Braided Flow Diverter Stents : A New Method to Evaluate Twisting Phenomenon; Prasanth Velvaluri et al. /Clin Neuroradiol/ December 2021 - Dec;31(4):1181-1186. doi: 10.1007/s00062-020-00991-2.,

CONCLUSION 

Potential causes:

• Incorrect loading movement with device

•  

  Production flaw (unlikely)

• Undersizing of FDS in wide-neck aneurysm? (not our case)

Technical solution:

• Remodeling balloon angioplasty
• Remodeling balloon pull-angioplasty
• SOS stentectomy (Snare on stent retriever) - in our case not necessary

How to avoid it?:

• Careful preparation for aneurysm embolization and careful loading of the device