A consecutive cohort of thrombectomy procedures from our prospectively maintained stroke database was analysed.
These were consecutive patients from 3 separate operators who have adopted the aspiration-first technique.
Patients are included even if the aspiration was not possible; i.e.
on an intention to treat basis.
The concept is to see the effect of this standardised approach on all patients.
As a control we included consecutive patients who underwent primary stent-retrieval by the same operators over a similar time period,
prior to commencing this technique.
We also analysed specifically those cases when the aspiration technique was in fact the first technique used.
Posterior circulation occlusions were excluded from the study.
For evaluation of the success of revascularisation,
original TICI scores were re-evaluated by an independent neuroradiologist.
If there was a disagreement from the original assessment,
a third reviewer evaluated the angiograms to determine a final TICI score.
We used the modified TICI score including 2c.
The number of passes were also noted and compared between the two groups.
We compared four time parameters between our aspiration-first technique and the stent-retriever technique: (i) groin puncture to first angiogram,
(ii) groin puncture to first reperfusion,
(iii) time from first angiogram to first reperfusion and (iv) duration of procedure.
Time from first angiogram to first reperfusion was used to compare the speed of the techniques with achieving reperfusion excluding any variation in difficulty in accessing the carotid artery.
The overall duration of procedure was used as a metric of success of the techniques.
Fig. 1: 83 y/o woman presented with right-sided hemiplegia and aphasia. PA digital subtraction angiography of the left anterior circulation, with the catheter tip in the distal left ICA. TICI 0 pre-thrombectomy (A), with a left M1 segment occlusion. Single pass of a SOFIA Plus aspiration catheter was performed, with a TICI 3 result (B).
Aspiration technique:
An 8 French short sheath is introduced to the common femoral artery.
A 6 French catheter inside an 8 French mach guide catheter is advanced to the aortic arch with a guidewire and the relevant large vessel of the neck is catheterised. The 6-8 combination is then advanced into the internal carotid artery with the 8 French guide advanced over the 6 French catheter for final tip placement in the proximal to mid internal carotid artery.
If there is a stenosis or occlusion of the ICA an attempt is made to cross this first without angioplasty or stenting.
The wire and 6 French catheter are removed. Angiography confirms site of vessel occlusion.
Continuous heparinised saline flush is attached to the catheter through a pressure pump.
A SOFIA Plus catheter is advanced through a rotating haemostatic “Y” valve attached to heparinised saline flush into the eight French guide catheter.
A 20mL syringe partially filled with saline is attached to the hub of the catheter.
Once the SOFIA Plus catheter extends beyond the tip of the 8 French guide catheter the 20mL syringe is switched,
following aspiration of any blood for a 10mL contrast filled syringe.
Contrast is trickled forward as the SOFIA Plus catheter advances.
The SOFIA Plus may be advanced through the distal internal carotid artery in this manner,
being careful to avoid pushing against resistance.
It is commonly possible to push this catheter to the proximal end of the thrombus in the ICA or M1 segment.
Inability to aspirate blood backwards through the SOFIA Plus indicates engagement with the thrombus.
A 50mL luer-lock lockable syringe is then attached to the catheter and fixed suction is applied for approximately 30 seconds.
It is usually necessary to withdraw the catheter dislodging the thrombus before the thrombus is aspirated into the catheter and syringe and rapid back flow is obtained.
If back flow is not obtained the catheter will have to be removed completely,
usually due to thrombus at the tip of the catheter and continuous aspiration is applied with the syringe that is locked on suction.
Angiography will determine whether further aspiration is required or suitable.