Edited by: Shakir Husain Hakim, Max Institute of Neurosciences, India
Reviewed by: Johanna Fifi, Albert Einstein College of Medicine, USA; Mohamed Elmahdy, Cairo University, Egypt
*Correspondence: Brian-Fred M. Fitzsimmons, Department of Neurology, Froedtert Hospital and Medical College of Wisconsin, 9200 West Wisconsin Avenue, Milwaukee, WI 53226, USA. e-mail:
This article was submitted to Frontiers in Endovascular and Interventional Neurology, a specialty of Frontiers in Neurology.
This is an open-access article subject to a non-exclusive license between the authors and Frontiers Media SA, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and other Frontiers conditions are complied with.
Advancements in endovascular devices and techniques for aneurysm coil embolization continue to expand the ability to treat complex aneurysms. Wide-neck aneurysms often require assistive devices and techniques to prevent coil prolapse into the parent artery during coil placement and to allow dense coil packing. Temporary parent artery occlusion, or “balloon remodeling,” has become a well-described assistive technique for coil embolization of wide-neck aneurysms (Moret et al.,
A search of our neuroendovascular database was performed to identify cases in which the Ascent balloon (Codman Neurovascular, Raynham, MA, USA) was used for cerebral aneurysm embolization during the first 12-month period that the new balloon was available at our institution. Clinical, demographic, and procedural data were obtained from charts and relevant angiographic images were reviewed.
Procedures were performed with patients under general anesthesia. A transfemoral arterial approach was used. Per protocol, patients were systemically heparinized to maintain an ACT level of 250–300 s, and a coaxial system including a 6F 070 Neuron guide catheter (Penumbra, Inc., San Leandro, CA, USA) was used. Images were obtained with biplane projections and a 3-D rotational digital subtraction angiogram was obtained for each patient. Working views were obtained after review of the 3-D rotational angiogram. The Ascent balloon was prepped following manufacturer recommendations. A 0.014′′ microwire was used to advance the Ascent balloon catheter to the aneurysm neck. The aneurysm lumen was accessed with a microcatheter. Intermittent temporary balloon inflation was performed at the time of coil placement (Figures
Eleven patients underwent balloon-assisted coil embolization of wide-neck aneurysms with the Ascent balloon system. Patient and aneurysm characteristics are summarized in the table (Table
Transient thrombus was identified distal to the site of balloon placement in the parent artery of one of the ruptured aneurysm cases (Case 1), which resolved completely after antiplatelet administration and without clinical sequelae.
Case | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
---|---|---|---|---|---|---|---|---|---|---|---|
Age (years) | 31 | 52 | 64 | 49 | 64 | 64 | 66 | 63 | 30 | 72 | 43 |
Sex | F | M | F | F | M | F | F | F | F | F | F |
Presentation | Ruptured | Ruptured | Unruptured | Unruptured | Unruptured | Unruptured | Unruptured | Unruptured | Unruptured | Unruptured | Ruptured |
Location | Left MCA | Right ACA at A1/ACoA junction | Left ICA, ophthalmic segment | BA, tip | ACoA | Left ICA, paraophthalmic | Left ICA, paraophthalmic | Left PCoA | Right MCA (Figure |
Left ICA, ophthalmic (Figure |
Right MCA |
Max diameter (mm) | 12 | 10 | 15 | 7 | 9 | 7 | 6 | 10 | 10 | 12 | 7.2 |
Neck (mm) | 6.3 | 7.8 | 7.5 | 5.2 | 5 | 5 | 3.5 | 7 | 3.8 | 6 | 3 |
Morphology | Multilobular (tri-lobed) | Irregular spherical | Irregular spherical | Spherical | Spherical with daughter sac | Spherical | Multilobular | Tri-lobed | Spherical blowout | Irregular | Irregular |
Size | 4 × 7 | 4 × 15 | 4 × 15 | 4 × 15 | 4 × 7 | 4 × 15 | 4 × 15 | 4 × 15 | 4 × 15 | 4 × 15 | 4 × 7 |
Position | M1 to opercular branch | Proximal R A1 to A2 | Aborted | Aborted | ACoA | Left ICA | Left ICA | Left ICA | M1 to inferior division | Left ICA | M1 to inferior division |
Guide catheter | 6 F 070 Neuron | 6 F 070 Neuron | 6 F 070 Neuron | 6 F 070 Neuron | 6 F 070 Neuron | 6 F 070 Neuron | 6 F 070 Neuron | 6 F 070 Neuron | 6 F 070 Neuron | 6 F 070 Neuron | 6 Fr 070 Neuron |
Additional balloon used | None | None | HyperGlide 4 × 15 | None | None | None | None | None | None | None | None |
Adjunctive bridge device | None | Neuroform 3 | Neuroform 3 | Neuroform stents in Y-configuration | None | Neuroform 3 | None | None | Enterprise (balloon within stent) | Neuroform 3 (deployed after coiling) | None |
Number of coils | 12 | 10 | 24 | 7 | 17 | 7 | 5 | 6 | 17 | 17 | 6 |
Embolization class | Class I | Class I | Class I | Class I | Class I | Class I | Class I | Class I | Class I | Class I | Class I |
Complication | Transient thrombus, resolution with abciximab | Transient thrombus R A2, resolution with abciximab | None | None | None | None | None | None | None | None | None |
In case 2, packing of the broad neck aneurysm resulted in temporary coil herniation into the right A2 segment producing a reduction in antegrade flow due to adherent thrombus. Abciximab was administered (15 mg) intravenously followed by placement of a Neuroform 3 stent across the aneurysm neck with successful repositioning of all coil loops into the aneurysm and improved antegrade flow. A partially inflated Ascent balloon was then placed within the stent for additional support.
Use of the Ascent balloon was unsuccessful in two cases. The inability to track the Ascent balloon around the ophthalmic segment in case 3 prohibited adequate delivery, while a HyperGlide balloon allowed successful positioning at the aneurysm neck. In case 4, multiple attempts were made to deliver the Ascent balloon, however tortuosity prohibited safe positioning of the balloon microcatheter. An alternative compliant balloon was also unsuccessfully attempted, and ultimately Y-configuration stenting was performed to secure a neck bridge.
We report our initial experience with a coaxial dual-lumen Ascent balloon catheter system for the remodeling technique in wide-neck aneurysm treatment. This is the largest series describing the use of this device for wide-neck aneurysm treatment. This report contributes to the growing body of literature describing novel techniques and new devices that expand the possibilities of endovascular treatment of complex aneurysms.
The purpose of temporary parent artery occlusion in aneurysm coil embolization is to prevent coil prolapse, improve coil positioning, and allow for greater density packing. A recent meta-analysis suggested that balloon-assisted coil embolization leads to greater initial occlusion rates and more durable occlusion when compared to unassisted coil embolization (Shapiro et al.,
Aneurysm size was large in our series, ranging from 6 to 15 mm. The average neck size was also large, ranging from 5.0 to 7.8 mm. These characteristics are important for balloon performance as larger neck size may pose greater challenge in initial balloon positioning and maintaining placement during repeated inflations.
Aneurysm locations varied, providing a reasonably well-distributed sample. The patient population was relatively young (average age 54 years) and vessel tortuosity was moderate. As with any device, navigation of tortuous vessels will hinder performance and this was possibly the cause of inability to safely position the Ascent balloon in cases 3 and 4. Improved distal support through use of a distal access catheter may reduce this limitation.
A unique characteristic of the Ascent balloon system is the dual-lumen design that allows delivery of the balloon catheter over a variety of microwires, allowing for flexibility in the choice of wires. Performance with use of different wires is not known and further experience may identify specific wires that provide an optimal pairing. This design may be of potential usefulness in the event of artery rupture. In the present series, this new device allowed use of an exchange-length wire, which is not feasible with other compliant aneurysm balloon catheters. Moreover, the over-the-wire devices do not allow for saline perfusion around the microwire or removing the wire to switch to a different microwire while leaving the balloon catheter in the body. Occlusion of the balloon holes with blood clots is another potential drawback of the over-the-wire balloons preventing full deflation on occasion.
The dual-lumen design allows for delivery of the Ascent balloon over an exchange wire, which can be useful in the balloon-in-stent remodeling technique (Figure
The ability of a device to track well within the cerebrovasculature, or the “trackability,” is an important characteristic of any neurointerventional device. This concept involves factors that affect the ability of a device to travel the course of a vessel, which include the inherent characteristics of a device, such as the flexibility and responsiveness to proximal manipulation, as well as the behavior of the device as a result of interaction with the surrounding vessel, such as the ability to glide. The Ascent balloon was not successfully used in two of our cases due to the inability to advance the balloon to the target lesion, which may have been from the device trackability in a tortuous cerebrovascular anatomy. The trackability may be related to interaction of the device over an exchange wire, a characteristic that may be important in wire selection. The trackability may also be affected by stiffness, a characteristic that may be theoretically increased due to the dual-lumen design.
Repeated balloon inflation may lead to unintended movement of the adjacent microcatheter resulting in loss of aneurysm lumen access, balloon migration, and parent artery rupture. Five cases required delivery of 10 or more coils, suggesting balloon positioning and access is well maintained throughout the technique of intermittent balloon inflation.
Complications from balloon remodeling primarily include thromboembolism, which range from about 2 to 8%, and parent artery perforation, which is under 2% in large series (Shapiro et al.,
Limitations of this report include the retrospective design and small sample size. Additionally, selection bias exists among operators and the decision to use one of three non-detachable compliant balloons available at our institution.
This initial experience demonstrates the feasibility and immediate results of a coaxial dual-lumen balloon catheter as an assistive device in coil embolization of wide-neck cerebral aneurysms. These findings are encouraging with expansion of the growing armamentarium of endovascular devices and techniques for the treatment of complex cerebral aneurysms. Larger series are needed to further evaluate this device for efficacy and long-term outcomes.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.