Balloon Gliding Technique: A novel use of balloon guiding catheters in accessing challenging circulations when treating acute ischemic stroke

Abstract

Background

Challenging arterial anatomy delays, or prevents timely endovascular treatment (EVT) of acute ischemic stroke (AIS). We introduce a new technique called ‘Balloon Gliding Technique (BGT)’ to overcome difficult arterial anatomy during EVT of AIS, utilizing flow-assistance to access challenging circulations.

Methods

Retrospective review of a prospectively collected database of all patients presenting to a single institution with AIS who underwent EVT was performed from January 2021 to June 2021. Patients in whom BGT was performed were assessed. BGT consists of advancing the balloon guide catheter in the cervical carotid artery while its balloon is inflated, and therefore carried by downstream flow.

Results

Of 51 patients presenting with AIS secondary to large vessel occlusion during the study period, five patients underwent BGT. All five patients had anterior circulation large vessel occlusions. Mean age of the BGT patients was 92.2 years, and all patients were females. A type 3 arch was present in all patients. BGT was performed in all cases following initial failure of conventional techniques to cannulate the target circulation. BGT was successful in achieving distal cervical carotid access in 4 out of the 5 patients in whom BGT was attempted. Successful recanalization (modified treatment in cerebral ischemia 2b-3) was obtained in all cases with no complications.

Conclusions

Balloon Gliding Technique (BGT) is a safe technique that can safely overcome challenging anatomy during endovascular treatment of acute ischemic stroke. Further studies can assist in demonstrating both its safety and effectiveness.

Introduction

Timely recanalization is a critical predictor of good stroke treatment outcome in patients presenting with large-vessel-occlusion acute ischemic stroke.^1–4 Causes of recanalization failure include access failure where there may be difficulty encountered in establishing cervical or intracranial access, or retrieval failure where there is an inability to successfully aspirate or retrieve the causative clot. ⁵ Challenging circulations are seen in older patients who have significant arterial elongation and tortuosity.^6–8 Specifically, type III arches, bovine arches and acutely angled innominate or left common carotid artery origins challenge the ability to secure distal access from a femoral approach. ⁹ Patients with such challenging circulations have prolonged procedure times, lower recanalization rates, and worse outcomes following endovascular treatment (EVT) of acute ischemic stroke (AIS).^6,7,10 Neuro-interventionalists utilize various techniques to access unfavorable vascular anatomy during EVT of AIS.^11,12 We introduce a novel “balloon gliding technique” (BGT) that can access challenging cerebrovascular anatomy, before abandonment of the preferred initial route to alternative access routes.

Material and methods

The data that support the findings of this study are available from the corresponding author upon reasonable request

We reviewed all patients presenting at a single-center between January 1^st, 2021 and June 30^th, 2021 with large vessel occlusion and acute ischemic stroke undergoing endovascular treatment. We evaluated all patients in whom balloon gliding technique (BGT) was utilized in attempting to access the target circulation. We reviewed each patient’s demographic information, clinical presentation, imaging findings, endovascular technical details, and outcomes. All patients underwent CT angiograms of the head and neck before their recanalization procedures.

Endovascular technique

Endovascular procedures were performed on a biplane angiography system (Allura Systems, Philips, Amsterdam, Netherlands). The procedures were initiated with moderate sedation, and converted to general anesthesia if clinically indicated. The standard technique for mechanical thrombectomy consisted of femoral access with an 8 French, 45 cm long sheath (Cordis BRITE TIP®, Hialeah, Florida). A FlowGate2™ (Stryker Neurovascular, Fremont, California) balloon guide catheter (BGC) was co-axially advanced over a 5 or 6 French vertebral catheter which had been placed in the cervical internal carotid artery (ICA) distally, as safely as possible anatomy permitting. If severe carotid tortuosity or challenging aortic arch anatomy led to failure in advancing the BGC into the cervical ICA, a stiff glidewire or reversed-angle catheter such as the Vitek or Simmons 2 catheter would be utilized to attempt distal catheterization. In case of failure of these initial techniques, Balloon Anchoring Technique (BAT) would be attempted as a fallback technique where the BGC would be initially advanced coaxially over a Vitek or Simmons 2 catheter placed in the proximal common carotid. ¹³ The BGC is next inflated to stabilize the system, the guidewire and diagnostic catheter are next gently inched forward to the cervical ICA through the balloon-inflated stabilized BGC. Once the guidewire and diagnostic catheter have been distally placed in the cervical ICA, the balloon is deflated, and the BGC is advanced coaxially into the distal ICA to the intended BGC target position for stable endovascular stroke treatment. In case of BAT failure to achieve distal catheterization, “balloon gliding technique or BGT” was subsequently attempted. BGT consists of inflating the BGC balloon, allowing the distal end of the BGC to be carried by anterograde flow, thereby incrementally advancing the inflated BGC over the guidewire and diagnostic or intermediate catheter to the desired target location using direct fluoroscopic and roadmap guidance.

Results

Fifty-one patients presented to our single center with acute ischemic stroke secondary to large vessel occlusion, and underwent mechanical thrombectomy between January 2021 to June 2021. Of these 51 patients, five patients required “balloon gliding technique” (BGT) to secure effective ICA positioning of the BGC. BGT was utilized in all five cases following unsuccessful efforts at utilizing other bail-out techniques. BGT was successful in successful ICA BGC positioning in 4 out of these 5 patients. All 5 patients were females with a mean patient age of 92.2 ± 4.7 years (mean ± Standard Deviation, range: 84–97 years). All 5 BGT patients presented with acute anterior circulation strokes secondary to large vessel occlusions. All 5 patients had type 3 aortic arches, defined when the distance between the origin of brachiocephalic artery and the top of the aortic arch is greater than 2 diameters of the left common carotid artery (LCCA). All 5 patients had moderate to severe tortuosity of the supra-aortic trunks/internal carotid arteries. BGT was attempted in all cases after failure of other bail-out techniques including various shaped catheters, stiff wires, and balloon anchoring technique. Successful recanalization (modified treatment in cerebral ischemia 2b-3) was obtained in all four cases where the BGC was successfully placed in the ICA. BGT failed in one patient (1/5) due to an acute kink/folding at the proximal common carotid artery. In this fifth patient, distal ICA recanalization was achieved by deploying a stent-retriever in the petrous ICA as a distal anchoring device, with additional tandem side-by-side placement of a stiff wire which together straightened the carotid kink, permitting BGC placement at the targeted ICA site. Patient demographics and clinical characteristics, imaging findings, endovascular technical details and outcome are summarized in Table 1. Representative cases are presented as Figure 1 and Supplemental Videos 1 and 2.

Table 1.

Table showing patient demographics, in addition to radiological and technical details of patients in whom balloon gliding technique (BGT) was used following conventional and bail-out failures.

	Patients	Age, Gender	Site of Occlusion	Aortic Arch type	Carotid Tortuosity	Techniques attempted before BGT	Technical Outcome
Patient 1	#1	94, F	Right M2	III, Bovine	Severe	SIM2 BAT SR	TICI 2b
Patient 2	#2	94, F	Left Carotid terminus	III	Moderate	SIM2 BAT	TICI 2b
Patient 3	#3	93, F	Right M2	III	Severe	SIM2 BAT	TICI 2c
Patient 4	#4	84, F	Left M1	III	Moderate	SIM2 BAT	TICI 3
Patient 5	#5	97, F	Right M1 Severe	III	Moderate	SIM2 BAT	TICI 2b

Abbreviations: F: Female; Sim2: Simmons catheter; SR: Stent retriever anchoring technique; BAT: Balloon anchoring technique; TICI: Thrombolysis In Cerebral Infarction.

Figure 1.

A 93 year old woman who presented with an acute stroke due to a right M2 occlusion. (a) Coronal CT angiogram of the aortic arch showing type III arch with the vertical distance between the origin of brachiocephalic artery (white arrow head) and the origin of the left subclavian artery (black arrow head) is greater than two times the diameter of the common carotid artery. (b) Initial attempt to catheterize the right carotid arteries using a Simmons 2 catheter failed because of the type three arch and the tandem severe tortuosity of the right internal carotid artery (Black Arrow). (c-f) Demonstration of the Balloon Gliding Technique. The brachiocephalic artery is catheterized using a Sim2 catheter followed by placement of the guidewire in the internal carotid artery. The BGC is next inflated to stabilize the system and the diagnostic/intermediate catheter is advanced into the cervical ICA. The inflated BGC is then incrementally co-axially advanced over the guidewire and diagnostic or intermediate catheter (white arrows).

Discussion

We introduce a novel flow-assisted application of an inflated balloon guide catheter for securing appropriate endovascular access in the treatment of acute large vessel occlusive strokes. This technique, termed ‘Balloon Gliding Technique (BGT)’, consists of the co-axial advancement of the inflated balloon guide catheter (BGC) over a telescoped smaller diameter catheter and/or wire. We have found this technique as helpful in overcoming unfavorable aortic and supra-aortic arterial anatomy. The BGT resulted in successful placement of balloon guide catheters in most patients (80%) in whom it was attempted once other bail-out techniques failed.

Various techniques have been described to overcome unfavorable vascular anatomy during the endovascular treatment of acute ischemic stroke. ¹¹ Balloon anchoring technique (BAT) utilizes an inflated balloon guide catheter anchored in a low position at the origin of the common carotid artery. Within the low-positioned and anchored BGC, the intermediate catheter and/or guidewire are coaxially advanced distally within the BGC if there is adequate fixation of the BGC to permit such advancement of the intermediate catheter and/or guidewire. ¹³ Once the intermediate catheter and/or guidewire have been navigated to a successfully high and secured position, the BGC balloon is then deflated and the guide catheter is advanced over the intermediate catheter and/or guidewire into the cervical ICA. BAT may fail in cases of severe tortuosity, and the system may herniate while attempting to advance the guide catheter over the high-positioned intermediate catheter and/or guidewire, following deflation of the BGC balloon. An alternative technique called Balloon-Assisted Tracking Technique has also been described in attempting to access tortuous or stenotic circulations when the side gap between the intermediate catheter and contained wire allows the tip of the catheter to act as an edge, that can catch on a fold or atherosclerotic ledge impeding its progress. ¹⁴ Balloon-Assisted Tracking Technique consists of inflating a balloon positioned at the tip of the intermediate catheter to overcome the step-off between the vessel stenosis and catheter. This results in effacing any side gap between the horizontal edge of the catheter tip and the guidewire, allowing the guidewire/balloon/catheter combination to more easily slide over ledges and folds. ¹⁴

The BGT we describe is in part based on both ‘Balloon Anchoring Technique’ and ‘Balloon Assisted Tracking Technique’, while adding an element of flow-directed cannulation as antegrade flow enters the common carotid artery, pulling the BGC into the target circulation. The most conspicuous difference in these techniques is that in BGT, the advancement of the guide catheter is performed while its balloon is inflated, whereas in BAT, the advancement of the guide catheter is performed following balloon deflation. BAT was attempted initially in all of our 5 patients undergoing BGT advancement, where BAT failed to achieve sufficient distal positioning or forward navigation of the intermediate/inner catheter after balloon deflation.

The mechanism of action of BGT may be due to either distal balloon-segment stiffening of the BGC once the balloon is inflated leading to greater forward axial-loading authority of the BGC tip, and less likelihood of the inflated segment to fold on itself and pop out of the vessel origin than when deflated, Alternatively, the success of BGT advancement could be secondary to flow related forward pressure helping to drag the balloon downstream while it is inflated, as long as there is antegrade flow into the ICA. In the event of a CCA occlusion or complete ICA occlusion, we may encounter less BGT success.

Our report therefore emphasizes a previously unrecognized additional benefit in using BGCs during mechanical thrombectomy of large vessel occlusion stroke. BGCs have been otherwise reported as offering faster and more successful recanalization with improved clinical outcomes in patients with acute ischemic stroke than non-balloon guide catheters.^15,16 Utilizing BGCs allows the utilization of BGT to achieve distal positioning of the BGC in the cervical ICA which may in certain instances further accelerate recanalization in patients with LVO-AIS. ¹⁷

Despite the safety of advancing the inflated BGC in the distal carotid artery in our pilot study, its benefits should be carefully weighed against the potential risks of cervical carotid dissection or showering distal emboli in case of significant atherosclerotic disease of the carotid arteries. While dissection is always a concern with an inflated balloon, there may be a tolerance of the cervical carotid arteries to a traveling inflated balloon. This is not uncommonly seen during retrieval of the stent retriever, there is a tendency of the inflated balloon guide catheter to ride forward to counter the backward retrieval force. We recommend that the inflated BGC should be advanced smoothly in the cervical carotid under direct fluoroscopy guidance and roadmap technique. The BGC is inflated in the same manner as when it is used for flow arrest during routine mechanical thrombectomy. Approximately 0.6 to 1 cc of diluted contrast (50:50) is injected via a one cc syringe under fluoroscopy guidance. Overinflation should be avoided to prevent vessel injury, dissection or distal emboli and to allow forward navigation of the inflated BGC without resistance. Underinflation should be avoided to maximize the flow related forward advancement of the BGC with an optimally inflated balloon as well as to increase the grasp of the balloon against the carotid wall to prevent catheter collapse. Until greater experience is gained with this technique, we believe that BGT should initially be reserved for use following failure of other techniques, prior to utilizing alternative access routes (i.e. radial access especially for type III arch and right sided occlusion).

Our study has several limitations including its small size, retrospective nature, and the fact that it was conducted at a single institution. There was therefore a sampling bias inherent to the small sample size which also affects the significance of the findings.

Conclusion

Balloon gliding technique consists of advancing an inflated balloon guide catheter over and distal to a contained intermediate or diagnostic catheter, leading with the balloon guide catheter. This technique can be utilized as a rescue maneuver in acute stroke patients with unfavorable aortic arch/craniocervical anatomy prior to accessing alternative access routes.

Supplemental Material

Video 1.

Video 2.

Nonstandard Abbreviations and Nonstandard Acronyms

AIS

Acute Ischemic Stroke

EVT

Endovascular Therapy

MT

Mechanical Thrombectomy

BGT

Balloon Gliding Technique

BGC

Balloon Guide Catheter

NIHSS

National Institute of Health Stroke Scale

mTICI

modified Thrombolysis in Cerebral Infarction

mRS

modified Rankin Scale

BAT

Balloon Anchoring Technique

ICA

Internal carotid artery

CCA

Common carotid artery