Balloon-assisted tracking technique to overcome intracranial stenosis during thrombectomy for stroke

Abstract

Anatomical vessel obstacles such as an intracranial stenosis in stroke are challenging and may lead to delayed clot access for thrombectomy. We describe a simple and effective technique to overcome the step-off between the intermediate catheter and an intracranial vessel stenosis during thrombectomy. The patient presented with acute embolic left middle cerebral artery occlusion and a favorable penumbral pattern. Clot access was made challenging by focal stenosis in the ipsilateral cavernous segment. The balloon-assisted tracking technique was effective in traversing the step-off to enable TICI 3 aspiration thrombectomy. This simple and effective technique should be kept in mind during stroke procedures where a proximal stenotic obstacle complicates access to the site of occlusion.

Background

Anatomical tortuosity or vessel stenosis in stroke may complicate thrombectomy procedures due to delayed or failed occlusion access and therefore lead to a lower recanalization rate.^1–3 While radial access or direct carotid puncture may overcome severe extracranial anatomical vessel tortuosity or failure of arch access,^{3 4} intracranial vessel stenosis requires a different access strategy. In contrast to an elective procedure, this obstacle needs to be overcome as soon as possible. Besides alternative routes through the circle of Willis, a potential simple and fast technique was previously described in the interventional cardiology literature during access for coronary angiography and percutaneous coronary interventions.⁵ With the so-called balloon-assisted tracking technique, a balloon is partially exposed out of the catheter tip and inflated with the dual goals of widening the vessel at the site of stenosis and overcoming the step-off between access and tracking catheters.^5–7

In this report we describe our experience with the balloon-assisted tracking technique during acute thrombectomy.

Case presentation

Patient history

A previously neurologically intact patient presented with acute onset of receptive aphasia (NIH Stroke Scale (NIHSS) score of 4). The patient had a significant history of coronary artery disease including a coronary artery bypass graft 20 years earlier and had received a left ventricular assist device (LVAD) plus biventricular pacemaker and implantable cardioverter defibrillator due to severely reduced ejection fraction. Computed tomography (CT) without contrast 30 min after onset did not show any abnormality (figure 1A). CT perfusion (figure 1B) and CT angiography showed a left inferior division middle cerebral artery (MCA) M2 occlusion with an area of perfusion mismatch in the posterior temporal and parietal lobes. No intravenous tissue plasminogen activator was given due to therapeutic anticoagulation with warfarin for the LVAD. The patient was in the thrombectomy window period and was taken to the interventional radiology suite after informed consent was obtained following discussion of the risks and benefits of the procedure with the patient’s family.

Figure 1.

Non-contrast CT (A) and CT perfusion showing left temporal-parietal mismatch (B). Frontal and lateral projection digital subtraction angiography showing left middle cerebral artery M2 inferior division occlusion (C). The distal horizontal cavernous segment of the left internal carotid artery showed a moderate short segment stenosis (white arrow) (D). Multiple attempts to overcome this stenosis using a Sofia 6 French (E) and Sofia 5 French (F) construct failed. Deployment of a Solitaire 6×30 mm stent retriever without intermediate catheter support did not sufficiently retrieve the clot (G).

Thrombectomy procedure

The patient was placed under general anesthesia by a LVAD-certified cardiac anesthesiologist. Both groins were sterilized in the usual fashion. An 8 French short sheath was placed into the right common femoral artery, followed by navigation of a Neuron MAX 088 guide catheter (Penumbra) into the left cervical internal carotid artery (ICA). Frontal and lateral projection digital subtraction angiography of the left ICA cranial circulation demonstrated occlusion of the dominant inferior division of the left MCA, with corresponding hypoperfusion of parietal and posterior temporal territories (figure 1C). Also noted was a short segment moderate stenosis of the distal horizontal cavernous segment of the left ICA (figure 1D). Several attempts to traverse the cavernous stenosis using a 5 or 6 French Sofia catheter (Microvention) supported by a Marksman microcatheter (Medtronic) and Transend 14 guidewire (Stryker) proved unfeasible (figure 1E-F). In both instances, however, the Marksman microcatheter easily passed the area of stenosis. Therefore, the Marksman catheter was navigated into the proximal M3 inferior division branch and a 6×30 Solitaire thrombectomy device (Medtronic) was deployed across the level of occlusion. Of note, using Solitaire as an anchor to improve trackability of the Sofia catheter also failed. Therefore, both the Marksman and Sofia 5 French catheters (below the stenosis) (figure 1G) were removed to maximize subsequent aspiration efficiency. After 5 min of deployment, the Solitaire device was removed during pump aspiration of the Neuron MAX 0.88 guide. Post-thrombectomy biplane angiography demonstrated persistent occlusion of the distal M2 segment of the MCA. A 3 MAX ACE catheter (Penumbra) coaxially introduced through the 6 French Sofia catheter was then used to perform suction thrombectomy (the 6 French Sofia catheter again could not be advanced past the level of cavernous stenosis). The 3 MAX ACE aspiration maneuver resulted in mild improvement with minimal re-opening of the inferior division.

At this point, a 4×10 transform balloon (Stryker) was placed into a 5 French Sofia catheter and the assembly navigated over a 014 Synchro guidewire (Stryker) to the level of the cavernous stenosis (figure 2A). The balloon was submaximally inflated partially within the Sofia catheter and in this fashion the Sofia/balloon unit was able to traverse the cavernous stenosis (figure 2B). The Sofia 5 French catheter was then navigated into the distal left M2 segment to the level of the occlusion, with manual aspiration successfully removing a tan-coloured embolus (TICI 3) (figure 2C and D). All catheters were removed and right groin hemostasis was achieved by deployment of a Mynx closure device. The patient was extubated in the angio suite and discharged to the medical ICU in a stable condition, followed by return to neurologic baseline (NIHSS 0) at 24 hours post-thrombectomy and discharge home 4 days later.

Figure 2.

Balloon-assisted tracking technique construct including an aspiration catheter (Sofia 5 French), a compliant balloon (Transform 4×10 mm) and a microwire (Transend 14) (A). An air bubble is seen in the balloon, which obviously should be avoided in patient use. Lateral fluoroscopy of the left internal carotid artery showing passage of the balloon/Sofia construct over the stenosis (B) and engaging the clot in the M2 segment with the Sofia 5 French catheter (C). Complete recanalization after aspiration (TICI 3) was observed on frontal and lateral projection digital subtraction angiography (D).

Treatment

See Case presentation

Outcome and follow-up

See Case presentation

Discussion

This case report illustrates a simple and efficient technique to overcome a vessel stenosis located proximal to the target lesion which failed to be passed with other maneuvers. With the so-called balloon-assisted tracking technique previously described elsewhere (eg, in cardiology to pass stenosis in the radial artery^5–7), we were able to overcome an intracranial stenosis of the left ICA in a patient with an MCA occlusion (figure 2A). By exposing a partially inflated compliant balloon out of the aspiration catheter tip, the vessel stenosis can be widened while eliminating step-off between the larger diameter aspiration catheter and its tracking microcatheter/microguidewire. This is the first report of adaptation of this technique to obtain distal access for thrombectomy in stroke and, in our experience, it is a useful technique to have in the interventional armamentarium.

Although our current practice favors aspiration thrombectomy over stent-retrievers, we typically use stent-retrievers when tandem lesion, proximal tortuosity, or other anatomical factors seem to support their use. When planning for a stent-retriever case a priori, we always use balloon guides, but in this case we initially used a stent-retriever. The lack of a balloon guide was suboptimal in terms of maximising stent-retriever efficacy. However, we suspect that tandem stenosis may limit the efficacy of balloon guide aspiration. Although we have used the same technique on several occasions to traverse cervical carotid steno-occlusive disease, intracranial experience is limited, the incidence of similar tandem lesions may be relatively low, and further experience is necessary.

Learning points.

• Anatomical tortuosity or vessel stenosis in stroke may complicate thrombectomy procedures due to delayed clot access and may lead to a lower successful recanalization rate.

• Balloon-assisted tracking can be a simple and effective maneuver to overcome the step-off between vessel stenosis and catheter.

• A submaximal inflated compliant balloon is partially exposed out of the intermediate catheter tip with the goal of widening the vessel stenosis and minimizing the catheter-microcatheter step-off.