Accounting for 87% of all types of stroke, ischemic stroke has both fatal and disabling consequences for affected patients. Ischemic stroke remains the leading cause of long-term disability; however, technologic and therapeutic advances made in the past decade offer significant potential to change this. Recent randomized controlled clinical trials have demonstrated the efficacy of endovascular intervention over tissue plasminogen activator (tPA) alone and have catalyzed the treatment of ischemic stroke, affording patients much more favorable outcomes than before. Landmark studies such as Solitaire With the Intention For Thrombectomy as Primary Endovascular Treatment (SWIFT PRIME) demonstrated that patients who suffered large-vessel anterior circulation occlusions treated with intravenous tPA in conjunction with the Solitaire stent retriever (Medtronic, Minneapolis, Minnesota) saw reductions in post-stroke disability. Alongside the diffusion-weighted imaging (DWI) or computed tomography perfusion (CTP) assessment with Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention with Trevo (Stryker Neurovascular, Fremont, California) (DAWN) trial, acute ischemic stroke (AIS) treatment underwent a shift leaning toward early and aggressive endovascular intervention. Newer stent retrievers have been introduced by various neurovascular companies offering providers different tools with the hope of improved recanalization rates and times and, ultimately, improved patient outcomes.
In addition to the proven efficacy of stent retrievers, a method known as a direct aspiration first pass technique (ADAPT) has emerged as an alternative technique for mechanical thrombectomy (MT) without the use of a stent retriever. This technique relies heavily on large-bore aspiration catheters.
Although clinical care and intervention for ischemic stroke have undeniably advanced in a positive direction, stroke intervention remains a high-risk, high-reward process. Regardless of extra effort taken to prevent complications, complications from vessel access to recanalization of affected vessels occur along various junctures during the stroke intervention. According to the results of recent randomized controlled trials, the risk of complications with sequelae for patients with MT is 15%. Here we discuss specific approaches in the endovascular treatment of AIS, focusing on common complications, tips for avoidance, and strategies to apply when complications do occur.
Seemingly simple to some and often overlooked by neophyte interventionists, arterial access is the basis by which intervention may be undertaken and the source of disastrous complications during thrombectomy. For stroke interventions, the femoral artery remains the standard for gaining access. However, novel techniques have emerged using the radial or brachial artery and, in rare instances, the carotid artery. In patients with intracranial vascular disease, co-existing peripheral vascular disease may render access difficult. Prior to intervention, vessel tortuosity and age-related changes to vessels may pose difficulties. Access-related groin and retroperitoneal hematomas can negatively alter the outcome of stroke intervention. Inadequate closure of the vessel at the end of the procedure can result in substantial blood loss, especially in instances where larger sheaths are used. In AIS intervention, time is of the essence. Groin access-to-vessel recanalization times are key; therefore, time lost in attempting to gain access can prolong the ischemic period and potentially alter clinical outcomes. If access is difficult to obtain within 2–3 minutes, ultrasound imaging should be used for assistance in gaining vascular access. If the standard transfemoral routes are deemed inappropriate or tenuous, quick adjustments should be made to use radial, brachial, or even direct carotid access. Misplaced sheaths may be temporarily left in place while proceeding with the thrombectomy. Close attention should be paid to preprocedure computed tomography angiography (CTA). CTA of the head and neck or CT stroke studies reveal arch anatomy, anatomical variations of large vessels, and possible vascular tortuosities that may hinder intracranial lesion access. Complications pertaining to access are avoidable if the neurointerventionist adequately anticipates the aforementioned factors prior to the procedure ( Box 53.1 ).
If access is difficult to obtain within 2–3 minutes, ultrasound imaging should be used for assistance in gaining vascular access.
From beginning to end, neurointerventional procedures predispose patients to having thromboembolic complications. There is an inherent risk of embolic material forming on catheters and guidewires introduced into the vasculature. Cleanliness and the organization of catheters and wires as they are introduced and removed can reduce risk. In addition, arterial dissection and vasospasm caused by the guide catheter prior to microcatheter and microwire manipulation can be associated with thromboemboli. Systematic heparinization of the patient is a strategy used to minimize thromboemboli alongside intra-arterial administration of verapamil in select instances of severe catheter-induced vasospasm.
More concerning for the neurointerventionist is the possibility of pre-existing clot fragments dislodging and leading to embolization of new territory resulting from manipulation of an endovascular device. Distal embolization is a legitimate concern that can be handled with different approaches. The use of stent retrievers of any kind mandates that a lesion be crossed with a microwire for facilitating the unsheathing of the stent retriever device. The sole act of crossing a lesion can dislodge clot debris downstream. Companies in the neurovascular sector sell varying components of their stent retriever devices including stent length, cell size, radial force, and other factors that may allow for better clot engagement. A plethora of devices ranging from stent retrievers to balloon guide catheters (BGCs) fill the toolbox of neurointerventionists and should be used based on their comfort and experience level with the understanding that no device is devoid of complications. Table 53.1 shows several of these devices, some of which are approved for use in MT by the U.S. Food and Drug Administration.
|Device||FDA approved||FDA-approved indication||Supporting evidence for FDA approval|
|MicroVention ERIC||No||NA a||NA|
|Neuravi EmboTrap II||No||NA a||Prospective, single-arm, multicenter—ongoing|
|Stryker Baby Trevo||Yes||Thrombectomy||Substantially equivalent|
|Medtronic Mindframe Capture||Yes||Thrombectomy||Substantially equivalent|
|Penumbra ACE68, Aspiration System||Yes||Thrombectomy||Prospective, single-arm, multicenter—completed|
|Walk Vascular ClearLumen||No||NA b||Substantially equivalent|
|Stryker AXS Catalyst 6||Yes||Intracranial access||Substantially equivalent|
|MicroVention Sofia Plus||Yes||Intracranial access||Substantially equivalent|
|Medtronic Arc||Yes||Intracranial access||Substantially equivalent|
|MIVI Neuroscience Mi-Axus||Yes||Intracranial access||Substantially equivalent|
|DePuy Synthes Envoy DA||Yes||Intracranial access||Substantially equivalent|
|BGCs||Yes||Intracranial access||Substantially equivalent|
|Medtronic Lazarus Effect Cover||No||NA||NA|