Intracranial atherosclerotic disease (ICAD) represents a major cause of stroke, especially prevalent among Asian and Black populations, characterized by the atherosclerotic narrowing of intracranial arteries and resulting in reduced cerebral blood flow (1, 2). Despite the advancements in antithrombotic therapies, ICAD remains associated with a high annual stroke recurrence rate of 4–19%, underscoring the need for more effective treatments (3, 4). Neuroendovascular therapies, such as percutaneous transluminal angioplasty and stenting (PTAS), have emerged as promising alternatives. Specifically, the introduction of the self-expanding Wingspan stent system (Stryker, Kalamazoo, MI, United States) has marked a significant milestone, albeit with outcomes in clinical trials such as SAMMPRIS and VISSIT, which showed more complication rate in the stenting groups than in the medical treatment group, highlighting the risk of ICAD stenting (5, 6).

Subsequent studies, including the WEAVE trial, have suggested that procedural refinements and careful patient selection may significantly mitigate these risks, demonstrating a notably lower complication rate, which showed a low 2.6% periprocedural complication rate in 152 cases (7, 8). Nevertheless, the recent CASSISS trial emphasized the necessity of comparing these endovascular strategies against medical management, showing no significant benefit in stroke prevention but a lower complication rate with the Wingspan stenting from previous reports (9, 10).

A critical factor in the procedural risk of ICAD stenting is the use of general anesthesia, known to induce hemodynamic changes and preclude intraoperative monitoring of the patient’s neurological status (11, 12). Given the concerns regarding procedural-related complications and the impact of general anesthesia on perioperative outcomes, our institution has adopted a novel approach by performing all ICAD stenting procedures under local anesthesia. This study aims to evaluate the safety, efficacy, and complication rates of awake stenting using the Wingspan system, offering insights into its potential advantages over conventional methods.

The primary focus of this study was to explore the feasibility of performing elective intracranial stenting procedures using the awake PTAS technique with the Wingspan system. The Wingspan stent system, a self-expanding stent, designed for use with the Gateway angioplasty balloon, has been scrutinized for its role in cerebral artery revascularization and stroke prophylaxis. However, it is noteworthy that there is a lack of randomized trials investigating the impact of different anesthesia techniques on clinical outcomes and complications in intracranial stenting procedures. Despite this gap in research, many medical institutions continue to administer intracranial stents under general anesthesia, with only a handful of studies indicating the feasibility of using the Wingspan system or other coronary stents under local anesthesia (13–16).

The SAMMPRIS study protocol has stipulated the necessity of performing the stenting procedure under general anesthesia to ensure patient immobility during the operation (6, 11, 17). However, there are concerns regarding the potential complications associated with general anesthesia. Utilizing local anesthesia for Wingspan intracranial stenting offers a clear advantage, primarily in avoiding the need for endotracheal intubation and minimizing hemodynamic fluctuations during induction. These factors are crucial, especially in patients with severe intracranial stenosis, as they have been linked to perioperative strokes (6, 11). By using local anesthesia, confounding variables originating from general anesthesia can be effectively eliminated, providing a safer alternative for patients undergoing intracranial stenting procedures.

From the surgeon’s perspective, dealing with severe stenosis in ICAD patients presents challenges due to poor image quality in the DSA roadmap caused by reduced blood flow. Manipulating the microcatheter to straighten parent vessels can inadvertently lead to unintended microwire entry into the wrong vessels, resulting in iatrogenic perforation (14). Drawing from our experience, we found that frequent updates of the DSA roadmap offer the most accurate wire delivery, crucial in preventing catastrophic complications. Additionally, real-time interaction with patients and monitoring neuralgic conditions provide invaluable feedback during critical steps such as angioplasty or passing the guidewire through the stenotic site, especially in challenging cases. Notably, our study did not observe intraoperative subarachnoid hemorrhage from wire perforation.

However, the use of local anesthesia in intracranial stenting raises concerns among surgeons. It may pose technical difficulties due to the risk of patient movement during surgery, potentially lowering the technical success rate. Frequent roadmap updates might be necessary to compensate for patient movements. In our study, we employed a custom-made head holder, similar to other research groups, to immobilize the patient during procedures (15). Additionally, we utilized a custom-made “acrylic platform” positioned over the patient’s trunk, providing additional support for the 300-cm wire and the entire stenting system. This setup guards against accidental or abrupt movements of the distal tip, preventing subarachnoid hemorrhage when changing catheters (18). By securely holding the wire on the acrylic platform with the assistant’s assistance, surgeons can confidently transition to the Wingspan stent system, alleviating concerns about inadequate wire support or wire-tip movement. Moreover, this approach reduces the discomfort experienced by conscious patients during the procedure.

In our study, we achieved a 100% technical success rate in awake stenting, an acceptable periprocedural complication rate of 8.9%, a mortality rate of 2.2%, and, notably, no incidents of procedure-related complications such as wire perforation or vessel rupture due to angioplasty. Compared to previously reported data on intracranial stents performed under conscious sedation or local anesthesia, Chamczuk et al. (15) demonstrated a 12.1% periprocedural complication rate and a 3.2% mortality rate, while Abou-Chebl et al. (13) reported a 14.6% periprocedural complication rate and a 2.5% mortality rate. Yu et al. (14) found a major stroke or death rate of 4.2% and a total periprocedural complications rate of 9.5%. Furthermore, Jiang et al. (16) reported using the Wingspan stent for vertebrobasilar stenosis, demonstrating the ability to timely identify neurological conditions in patients, with low complication rates in the posterior circulation at 7%, representing a significant improvement compared to historic controls. Among these studies, the procedure-related complication rate, specifically wire perforation ranged from 1.5 to 6.2%. Our study exhibited promising results. Therefore, the overall results of intracranial stenting under local anesthesia suggest effectiveness and safety.

The endovascular recanalization procedure for extracranial internal carotid artery stenosis under conscious sedation or local anesthesia has become a widely accepted practice. We consider the application of the Wingspan stent system under local anesthesia as a natural extension of this approach. For experienced surgeons, performing delicate stenting procedures under local anesthesia can potentially result in safer and more successful outcomes for patients. Utilizing the patient’s consciousness, surgeons can actively assess brain perfusion status, a crucial factor in such intricate procedures. Evidence from a retrospective study on carotid artery stenting (CAS) revealed that patients under general anesthesia had 2.3 times higher odds of in-hospital mortality and twice the odds of extended hospital length of stay when compared to those under local anesthesia (19). Many surgeons prefer employing local anesthesia for CAS procedures as it allows for superior neurological assessment (19, 20). Similarly, in the case of Wingspan stenting, which involves high-risk manipulation of intracranial vessels, local anesthesia offers surgeons an advantage to evaluate the patient’s condition during the procedure. Furthermore, there is some degree of hypoperfusion and unintentional hyperventilation in the neuro-endovascular procedure in general anesthesia, which may lead to cerebral ischemia and induce poor outcomes (11, 12).

Complications arising from intracranial stenting using the Wingspan system often stem from perforator territories (4, 10, 18, 21). Several mechanisms have been postulated to explain these complications. First, according to a simulated biomechanical model of the Wingspan stent, structural deformation of the perforator orifice can occur after stent deployment, potentially leading to perforator stroke (22). Second, the theory of the “snow-plowing effect” suggests that stent expansion displaces the atheroma plaque occluding perforators, increasing the risk of perforator infarction (16, 23). Finally, the placement of the Wingspan stent system can induce the straightening of the tortuous vessels, which can cause kinking and overstretching of perforators, impairing blood flow, and resulting in ischemia (16). Given these hypotheses, it is challenging to prevent all perforator strokes, even with an experienced surgeon. Therefore, it becomes crucial to focus on reducing the risk of perforator infarction, especially in “perforator-bearing” arteries such as MCA and BA, to enhance the clinical outcomes of ICAD procedures. In our study involving patients under local anesthesia, we observed that perforator strokes occurred in only one patient in a perforator-bearing artery, which was a lower incidence than in other studies. Under local anesthesia, surgeons can potentially mitigate the risk by avoiding oversize angioplasty, closely monitoring the patients’ neurological conditions of patients, and reducing distal vessel ischemia. This vigilant approach may contribute significantly to minimizing complications related to perforator infarction.

Local anesthesia in intracranial stenting procedures with the Wingspan system offers distinct advantages including real-time monitoring of the patient’s neurological status and a potential reduction in the risk of perforator stroke. In our series, it also indicated no procedure-related complications, such as wire perforation. While this study sheds light on the potential benefits of using local anesthesia and awake stenting using the Wingspan system, surgeons should remain cautious among patients with perforator-bearing artery stenosis, as they may have a higher risk of complications.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

The studies involving humans were approved by Taichung Veteran General Hospital. The studies were conducted in accordance with the local legislation and institutional requirements. The participants provided their written informed consent to participate in this study.

M-SL: Writing – original draft. C-WH: Writing – review & editing. Y-ST: Supervision, Validation, Writing – original draft, Writing – review & editing.