This article reviews essential neurointerventional tools approved in the United States, including catheters and wires, coils, flow diverters, balloons, stents, and devices for mechanical thrombectomy and thrombolysis. These devices are the result of decades of technical development; this article will also briefly trace the evolution of these devices, with an emphasis on the most influential developments.
Key points
- •
A guide catheter is a catheter that is typically placed in the internal carotid artery or vertebral artery and accommodates microcatheters and other devices.
- •
Since the introduction of the detachable coil by Guglielmi (GDC coils) in 1991, coiling has become the mainstay of endovascular treatment of aneurysms.
- •
Flow diversion functions by placing a wire mesh stent within the parent vessel, across the aneurysm, leading to thrombosis of the aneurysm with preservation of flow through the parent vessel and its branches.
- •
Balloons have found a variety of neurointerventional applications, including extracranial and intracranial balloon angioplasty, balloon-assisted thrombectomy and thrombolysis, balloon-assisted coiling, balloon test occlusion, and balloon-expandable stent placement.
- •
Currently, several self-expanding stents are available for carotid angioplasty and stenting. Stents used for this indication are either tapered or straight and manufactured with open- or closed-cell design.
Catheters and wires
Diagnostic Catheters and Wires
Several catheters are suitable for diagnostic cerebral and spinal angiography ( Fig. 1 ). Angled taper and vertebral catheters are both excellent all-purpose diagnostic catheters. Simmons 1 through 3 catheters are preferred for spinal angiography, left common carotid artery access, and a tortuous or bovine-configured aortic arch. The CK-1, or HN-5, facilitates left common carotid artery or right vertebral artery access, while the H1, or Headhunter, is preferred for right subclavian and right vertebral artery access. The Newton catheter is another alternative for tortuous anatomy on older patients. Hydrophilic wires of variable diameter (eg, angled Glidewire [Terumo Medical, Somerset, NJ, USA]) are used for catheter navigation.
Guide Catheters
A guide catheter is a catheter that is typically placed in the internal carotid artery or vertebral artery and accommodates microcatheters and other devices. Preferably it is 6 French in caliber to allow for guide catheter angiograms with microcatheters or other devices in place and is available with straight or angled tips. A straight catheter, as the name would imply, is useful in relatively straight vessels but usually requires a wire exchange, while angled catheters are easier to navigate and advantageous when the final position of the catheter tip is in the curve of a vessel. Commonly used guide catheters include the Neuron system (Penumbra, San Leandro, CA, USA), Guider Softip XF (Stryker Neurovascular, Fremont, CA, USA), Envoy (Codman, Raynham, MA, USA), Cook Shuttle and Northstar Lumax (Cook, Bloomington, IN, USA), Merci Balloon Guide (Concentric Medical, Mountain View, CA, USA), ReFlex (Reverse Medical, Irvine, CA, USA), Berenstein (Boston Scientific, Natick, MA, USA), and Pinnacle Destination (Terumo Medical, Somerset, NJ, USA). The 6F 0.053 in Neuron is soft and flexible, allowing for positioning in the distal internal carotid or vertebral artery but less stable than other catheters. The Guider Softip XF has a soft, atraumatic tip that minimizes risk of vasospasm and dissection in narrow, tortuous vessels but is prone to fall into the aortic arch. The Envoy is relatively rigid and provides a good platform in tortuous vessels with large internal lumen but has a stiff, sharp-edged tip, thus increasing the risk of vessel damage. The Cook Shuttle is another catheter that provides a very large, stable platform.
Balloon Guide Catheters
The Merci Balloon Guide catheter is capable of temporarily occluding flow in the carotid or vertebral artery during thrombectomy but is prone to fall into the aortic arch. The Berenstein and Cello (eV3 Neurovascular, Irvine, CA, USA) balloon guides allow for control of proximal flow to prevent distal migration of embolic agents.
Microcatheters
A microcatheter provides access for treatment of a vascular lesion and is available in various sizes and shapes. Preshaped microcatheters are preferred for accessing aneurysms that arise from the parent vessel at an acute angle. When appropriately preshaped devices are unavailable, steam shaping is an option. Catheters have hydrophilic coating to reduce thrombogenicity. Smaller microcatheters permit better guide catheter angiograms, while larger and stiffer microcatheters provide stability when catheter access is tenuous because of the vascular anatomy. Single-tip and two-tipped microcatheters are available, and two-tipped microcatheters are necessary for aneurysm coiling. The two tips in microcatheters used for aneurysm coiling are always 3 cm apart and can be used for measurements or calibration. Commonly used microcatheters include the Excelsior SL-10 and Excelsior 1018 (Stryker Neurovascular, Fremont, CA, USA), Echelon 10, Ultraflow, and Marksman (all ev3, Irvine, CA, USA), Magic microcatheter (AIT-Balt, Miami, FA, USA), and Prowler Select Plus (Codman, Raynham, MA, USA). The Excelsior SL-10 can be used for 10- and 18-system coils. The Echelon 10 and Ultraflow are compatible for onyx and N-butyl cyanoacrylate (NBCA) embolization. The Marksman is fairly robust and useful for Neuroform EZ (Stryker Neurovascular, Fremont, CA, USA) stent deployment. The Excelsior 1018 accommodates 10- and 18-system coils and is suitable for polyvinyl alcohol (PVA) embolization. Use of the Prowler Select Plus is preferred with the Enterprise Vascular Reconstruction System (Codman, Raynham, MA, USA).
Microwires
Various microwires are available that differ in size, degree of stiffness, visibility on fluoroscopy, and the ability to shape, steer, track, and torque. Commonly used microwires include the Synchro-14, Transend EX Floppy tip, or Platinum (all Stryker Neurovascular, Fremont, CA, USA); the Neuroscout 14 Steerable Guidewire (Codman, Raynham, MA, USA); and Headliner J-tip (Terumo Medical, Somerset, NJ, USA). The Synchro-14 is flexible, suitable for navigation through complex anatomy and into small aneurysms. The Neuroscout 14 Steerable Guidewire maintains shape, permitting exceptional torque control. The Headliner J-tip is good for uncomplicated anatomy, as the J-tip is atraumatic and tends to follow the straightest vessel.
Intermediate Catheters
Intermediate catheters (eg, Distal Access Catheter [Stryker Neurovascular, Fremont, CA, USA], Revive Intermediate Catheter [Codman, Raynham, MA, USA], and Fargo and FargoMAX [Balt Extrusion, Montmorency, France]) are sized between a guide catheter and a microcatheter and provide stable access by functioning as a bridge between the 2 catheters in triaxial arrangement (microwire and microcatheter, intermediate catheter, and guide catheter). First developed to stabilize the Merci devices (Stryker Neurovascular, Fremont, CA, USA), intermediate catheters have been found to be helpful with tortuous cerebrovascular anatomy, need for remote access, and thrombectomy by reducing the laxity and bend of the microcatheter, therefore facilitating navigation.
Catheters and wires
Diagnostic Catheters and Wires
Several catheters are suitable for diagnostic cerebral and spinal angiography ( Fig. 1 ). Angled taper and vertebral catheters are both excellent all-purpose diagnostic catheters. Simmons 1 through 3 catheters are preferred for spinal angiography, left common carotid artery access, and a tortuous or bovine-configured aortic arch. The CK-1, or HN-5, facilitates left common carotid artery or right vertebral artery access, while the H1, or Headhunter, is preferred for right subclavian and right vertebral artery access. The Newton catheter is another alternative for tortuous anatomy on older patients. Hydrophilic wires of variable diameter (eg, angled Glidewire [Terumo Medical, Somerset, NJ, USA]) are used for catheter navigation.
Guide Catheters
A guide catheter is a catheter that is typically placed in the internal carotid artery or vertebral artery and accommodates microcatheters and other devices. Preferably it is 6 French in caliber to allow for guide catheter angiograms with microcatheters or other devices in place and is available with straight or angled tips. A straight catheter, as the name would imply, is useful in relatively straight vessels but usually requires a wire exchange, while angled catheters are easier to navigate and advantageous when the final position of the catheter tip is in the curve of a vessel. Commonly used guide catheters include the Neuron system (Penumbra, San Leandro, CA, USA), Guider Softip XF (Stryker Neurovascular, Fremont, CA, USA), Envoy (Codman, Raynham, MA, USA), Cook Shuttle and Northstar Lumax (Cook, Bloomington, IN, USA), Merci Balloon Guide (Concentric Medical, Mountain View, CA, USA), ReFlex (Reverse Medical, Irvine, CA, USA), Berenstein (Boston Scientific, Natick, MA, USA), and Pinnacle Destination (Terumo Medical, Somerset, NJ, USA). The 6F 0.053 in Neuron is soft and flexible, allowing for positioning in the distal internal carotid or vertebral artery but less stable than other catheters. The Guider Softip XF has a soft, atraumatic tip that minimizes risk of vasospasm and dissection in narrow, tortuous vessels but is prone to fall into the aortic arch. The Envoy is relatively rigid and provides a good platform in tortuous vessels with large internal lumen but has a stiff, sharp-edged tip, thus increasing the risk of vessel damage. The Cook Shuttle is another catheter that provides a very large, stable platform.
Balloon Guide Catheters
The Merci Balloon Guide catheter is capable of temporarily occluding flow in the carotid or vertebral artery during thrombectomy but is prone to fall into the aortic arch. The Berenstein and Cello (eV3 Neurovascular, Irvine, CA, USA) balloon guides allow for control of proximal flow to prevent distal migration of embolic agents.
Microcatheters
A microcatheter provides access for treatment of a vascular lesion and is available in various sizes and shapes. Preshaped microcatheters are preferred for accessing aneurysms that arise from the parent vessel at an acute angle. When appropriately preshaped devices are unavailable, steam shaping is an option. Catheters have hydrophilic coating to reduce thrombogenicity. Smaller microcatheters permit better guide catheter angiograms, while larger and stiffer microcatheters provide stability when catheter access is tenuous because of the vascular anatomy. Single-tip and two-tipped microcatheters are available, and two-tipped microcatheters are necessary for aneurysm coiling. The two tips in microcatheters used for aneurysm coiling are always 3 cm apart and can be used for measurements or calibration. Commonly used microcatheters include the Excelsior SL-10 and Excelsior 1018 (Stryker Neurovascular, Fremont, CA, USA), Echelon 10, Ultraflow, and Marksman (all ev3, Irvine, CA, USA), Magic microcatheter (AIT-Balt, Miami, FA, USA), and Prowler Select Plus (Codman, Raynham, MA, USA). The Excelsior SL-10 can be used for 10- and 18-system coils. The Echelon 10 and Ultraflow are compatible for onyx and N-butyl cyanoacrylate (NBCA) embolization. The Marksman is fairly robust and useful for Neuroform EZ (Stryker Neurovascular, Fremont, CA, USA) stent deployment. The Excelsior 1018 accommodates 10- and 18-system coils and is suitable for polyvinyl alcohol (PVA) embolization. Use of the Prowler Select Plus is preferred with the Enterprise Vascular Reconstruction System (Codman, Raynham, MA, USA).
Microwires
Various microwires are available that differ in size, degree of stiffness, visibility on fluoroscopy, and the ability to shape, steer, track, and torque. Commonly used microwires include the Synchro-14, Transend EX Floppy tip, or Platinum (all Stryker Neurovascular, Fremont, CA, USA); the Neuroscout 14 Steerable Guidewire (Codman, Raynham, MA, USA); and Headliner J-tip (Terumo Medical, Somerset, NJ, USA). The Synchro-14 is flexible, suitable for navigation through complex anatomy and into small aneurysms. The Neuroscout 14 Steerable Guidewire maintains shape, permitting exceptional torque control. The Headliner J-tip is good for uncomplicated anatomy, as the J-tip is atraumatic and tends to follow the straightest vessel.
Intermediate Catheters
Intermediate catheters (eg, Distal Access Catheter [Stryker Neurovascular, Fremont, CA, USA], Revive Intermediate Catheter [Codman, Raynham, MA, USA], and Fargo and FargoMAX [Balt Extrusion, Montmorency, France]) are sized between a guide catheter and a microcatheter and provide stable access by functioning as a bridge between the 2 catheters in triaxial arrangement (microwire and microcatheter, intermediate catheter, and guide catheter). First developed to stabilize the Merci devices (Stryker Neurovascular, Fremont, CA, USA), intermediate catheters have been found to be helpful with tortuous cerebrovascular anatomy, need for remote access, and thrombectomy by reducing the laxity and bend of the microcatheter, therefore facilitating navigation.
Related posts:
Pitfalls and Complications Management in the Endovascular Treatment of Aneurysms
Endovascular Management of Cavernous and Paraclinoid Aneurysms
Cerebral Vasospasm
Vertebrobasilar Fusiform Aneurysms
Endovascular Management and Treatment of Acute Ischemic Stroke
Endovascular Management of Intracranial Atherosclerosis
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
