Embolization Device Research Articles

Off-label in-silico flow diverter performance assessment in posterior communicating artery aneurysms.

The posterior communicating artery (PComA) is among the most common intracranial aneurysm locations, but flow diverter (FD) treatment with the widely used pipeline embolization device (PED) remains an off-label treatment that is not well understood. PComA aneurysm flow diversion is complicated by the presence of fetal posterior circulation (FPC), which has an estimated prevalence of 4-29% and is more common in people of black (11.5%) than white (4.9%) race. We present the FD-PComA in-silico trial (IST) into FD treatment performance in PComA aneurysms. ISTs use computational modeling and simulation in cohorts of virtual patients to evaluate medical device performance. We modeled FD treatment in 118 virtual patients with 59 distinct PComA aneurysm anatomies, using computational fluid dynamics to assess post-treatment outcome. Boundary conditions were prescribed to model the effects of non-fetal and FPC, allowing for comparison between these subgroups. FD-PComA predicted reduced treatment success in FPC patients, with an average aneurysm space and time-averaged velocity reduction of 67.8% for non-fetal patients and 46.5% for fetal patients (P<0.001). Space and time-averaged wall shear stress on the device surface was 29.2 Pa averaged across fetal patients and 23.5 Pa across non-fetal (P<0.05) patients, suggesting FD endothelialization may be hindered in FPC patients. Morphological variables, such as the size and shape of the aneurysm and PComA size, did not affect the treatment outcome. FD-PComA had significantly lower treatment success rates in PComA aneurysm patients with FPC. We suggest that FPC patients should be treated with an alternative to single PED flow diversion.

Our Experience with the Low-Profile Braided Occluder: A Case Series of Splenic Artery Embolization in Three Trauma Patients

AbstractThe spleen is the most injured intra-abdominal organ, with splenic injuries constituting 42 to 49% of all abdominal injuries. Due to this vulnerability and the fact that splenic ruptures can potentially result in life-threatening hemorrhage, finding quick and efficient ways to control splenic bleeding in a trauma setting can improve patient outcomes. Recently, the U.S. Food and Drug Administration cleared the low-profile braided occluder (LOBO; Okami Medical, Aliso Viejo, California, United States), a vascular occlusion system designed to rapidly occlude vessels by using a high-density, uniform small pore structure. We present a small case series describing the use of the LOBO device for proximal splenic embolization in three trauma patients. Our report suggests that the LOBO device is safe and efficient for proximal splenic artery embolization as all three of our patients had a successful outcome with no complications; furthermore, we believe using the LOBO device may enhance patient and provider safety by decreasing fluoroscopic time and radiation dose, though further studies are needed to support this.

CFD investigations of a shape-memory polymer foam-based endovascular embolization device for the treatment of intracranial aneurysms.

The hemodynamic and convective heat transfer effects of a patient-specific endovascular therapeutic agent based on shape memory polymer foam (SMPf) are evaluated using computational fluid dynamics studies for six patient-specific aneurysm geometries. The SMPf device is modeled as a continuous porous medium with full expansion for the flow studies and with various degrees of expansion for the heat transfer studies. The flow simulation parameters were qualitatively validated based on the existing literature. Further, a mesh independence study was conducted to verify an optimal cell size and reduce the computational costs. For convective heat transfer, a worst-case scenario is evaluated where the minimum volumetric flow rate is applied alongside the zero-flux boundary conditions. In the flow simulations, we found a reduction of the average intra-aneurysmal flow of > 85% and a reduction of the maximum intra-aneurysmal flow of > 45% for all presented geometries. These findings were compared with the literature on numerical simulations of hemodynamic and heat transfer of SMPf devices. The results obtained from this study can serve as a guide for optimizing the design and development of patient-specific SMPf devices aimed at personalized endovascular embolization of intracranial aneurysms.

Design of thermally programmable 3D shape memory polymer-based devices tailored for endovascular treatment of intracranial aneurysms

Despite recent technological advancements in endovascular embolization devices for treating intracranial aneurysms (ICAs), incomplete occlusion and aneurysm recanalization remain critical challenges. Shape memory polymer (SMP)-based devices, which can be manufactured and tailored to patient-specific aneurysm geometries, possess the potential to overcome the suboptimal treatment outcome of the gold standard: endovascular coiling. In this work, we propose a highly porous patient-specific SMP embolic device fabricated via 3D printing to optimize aneurysm occlusion, and thus, improve the long-term efficacy of endovascular treatment. To facilitate device deployment at the aneurysm via Joule-heating, we introduce a stable, homogeneous coating of poly-pyrrole (PPy) to enhance the electrical conductivity in the SMP material. Using an in-house pulse width modulation circuit, we induced Joule-heating and characterized the shape recovery of the PPy-coated SMP embolic devices. We found that the employed PPy coating enables enhanced electrical and thermal conductivity while only slightly altering the glass transition temperature of the SMP material. Additionally, from a series of parametric studies, we identified the combination of catalyst concentration and pyrrole polymerization time that yielded the shape recovery properties ideal for ICA endovascular therapy. Collectively, these findings highlight a promising material coating for a future coil-free, personalized shape memory polymer (SMP) embolic device, designed to achieve long-lasting, complete occlusion of aneurysms.

Important Notes for Preventing Entrapment of Distal Filter-based Embolic Protection Device in Carotid Artery Stenting.

Failure to retrieve a distal filter-based embolic protection device (EPD) is a potential complication of carotid artery stenting. This may be caused by trapping of the proximal marker of the EPD within the stent tip marker. Maintaining an adequate distance between the two can prevent this. We examined the behavior of several stent-filter-based EPD combinations, focusing on their propensity to become trapped or disengage in vitro. Four physicians subjectively rated the force required to result in trapping using a 5-point scale. Moreover, the force required to disengage trapped devices was evaluated. The Casper stent-Spider FX EPD combination was difficult to disengage when entrapment occurred, which suggested that this phenomenon tended to occur with this combination. The stent tip marker of the closed-cell stents advanced as they shortened, which may be a unique feature of closed-cell stents. Although trapping is uncommon, it can cause serious complications. To prevent these complications, device characteristics should be well understood before they are used in patients.

Analyzing the safety and efficacy of pipeline embolization device in pediatric aneurysms: insight from a mul-ticenter cohort and pooled analysis.

Pediatric patients with intracranial aneurysms face high risks of spontaneous subarachnoid hemorrhages. Despite its approval for adults aged 22 and above, the Pipeline Embolization Device (PED, Covidien/Medtronic, Irvine, California, USA) is being considered for younger patients due to its efficacy. This study aims to assess the safety and effectiveness of using PEDs in pediatric aneurysm treatment. A retrospective study across 14 institutions identified 25 patients (age ≤ 18) treated with PED from November 2014 to October 2019. A literature review included all published pediatric aneurysm cases treated with PED from 2007 to 2023. Analyzed data included patient demographics, aneurysm characteristics, treatment, clinical outcomes, and complications. We analyzed 81 pediatric patients, including 25 from the multi-center registry and 56 from 38 relevant literature. In the entire cohort of 81 patients, mean age of the patients was 11.9 ± 4.0 years (ranged from 9 months to 18 years), with 58.0% males. Ruptured aneurysms were observed in 7 patients (8.6%), whereas 43 patients (53.1%) harbored large/giant aneurysms. The aneurysm occlusion rate was 87.7% during the median 7 months follow-up. Complications occurred in 12.3% of patients, resulting in morbidity in 5 cases (6.1%) and mortality in 4 cases (4.9%). Patient age was not associated with the occurrence of aneurysm residual, complications, and mortality following PED treatment. PED can be effective for pediatric aneurysms, but morbidity and mortality can be substantial compared to the adults. Surgical timing should depend on clinical judgment and patient factors, without age-related delays.

A Woven EndoBridge dislodging from an aneurysm 12 days after the implantation procedure: illustrative case.

The Woven EndoBridge (WEB) is an effective embolization device. A few cases of WEB migration have been reported as adverse events, and most occurred during the procedure. A case of internal carotid artery (ICA) occlusion due to a trapped WEB, which occurred 12 days after the implantation procedure, is reported. A woman in her 70s was referred for an enlarged left ICA aneurysm during follow-up. A WEB SL 5 × 3 was chosen as the embolic device, and the implantation procedure was completed uneventfully. The patient's postoperative course was good, and she was discharged from the hospital. However, 12 days later, she was brought to the authors' hospital because the WEB device was trapped and occluded in the left ICA. The trapped WEB could not be retrieved using a gooseneck snare or stent retriever, but suction from a Sofia catheter released the trapped device, allowing it to be repositioned within the aneurysm. Most cases of WEB migration occur during surgery. In the present case, migration occurred 12 days after surgery, and to the best of the authors' knowledge, no similar cases have been reported. It is important to keep in mind that there are cases similar to the current case. https://thejns.org/doi/10.3171/CASE24278.

Cerebral emboli detection and autonomous neuromonitoring using robotic transcranial Doppler with artificial intelligence for transcatheter aortic valve replacement with and without embolic protection devices: a pilot study

BackgroundPeriprocedural ischemic stroke remains a serious complication in patients undergoing transcatheter aortic valve replacement (TAVR). We used a novel robotic transcranial Doppler (TCD) system equipped with artificial intelligence (AI) for...

Outcome study of the Pipeline Vantage Embolization Device (second version) in unruptured (and ruptured) aneurysms (PEDVU(R) study)

BackgroundThe Pipeline Vantage Embolization Device (PEDV) is the fourth-generation pipeline flow diverter for intracranial aneurysm treatment. There are no outcome studies for the second PEDV version. We aimed to evaluate...

Criteria for PAVM Reintervention.

Background/Objectives: To propose criteria for retreating previously embolized PAVMs and determining the effectiveness of the criteria to prevent paradoxical embolization. Methods: A retrospective review of patients with PAVMs treated at a single HHT center of excellence between 1 January 2013, and 10 September 2023, was performed. Patients with PAVM recurrence were either retreated or observed based on the following criteria for PAVM reintervention: 1. Embolic device(s) not creating a sufficiently dense matrix, such that a channel through them may be >/ 2 mm; 2. Accessory feeding artery or pulmonary collateral >/ 2 mm; 3. Hemoptysis in a patient with no other explanation. Results: A total of 438 PAVMs were treated in 151 patients, including 106 patients with definite, 14 possible, and 31 doubtful HHT. Post-embolization PAVM recurrence occurred in 36 patients (36/151, 23.8%), including 15 patients (15/151, 9.9%) with 22 PAVMs (22/438, 5.0%) meeting criteria for reintervention. A total of 21 patients (21/151, 13.9%) with recurrence did not meet reintervention criteria and were therefore observed. Pre-treatment paradoxical embolization occurred in 36 patients (36/151) for a lifetime prevalence rate of 23.7%. Post-treatment paradoxical embolization did not occur in any patients following PAVM embolization (0/151). There was one case of iatrogenic paradoxical embolization in a patient being treated for systemic collateral reperfusion and hemoptysis. However, this was not included given that it was not a spontaneous event. Conclusions: Utilizing modern embolization techniques and devices, the proposed reintervention criteria, and screening intervals, paradoxical embolizations can be effectively prevented in patients with PAVMs.

Comparison of Thromboembolic Complications After Carotid Artery Stenting with and without Using Protection Devices: A Systematic Review and Meta-Analysis Study

Background: This study compared the rate of thromboembolic events during carotid angioplasty and stenting (CAS) with and without embolic protection devices (EPDs). We reviewed literature to find studies comparing embolic event rates during CAS with and without EPDs and conducted a meta-analysis to determine the safer approach.Methods: The Embase, PubMed, and Web of Science databases were thoroughly searched following PRISMA guidelines. Each estimation was executed using random-effects models. The I2 index was used to assess the heterogeneity among the studies. Egger and Begg’s tests were applied to evaluate publication bias. Stata version 14.2 was used for statistical analysis.Results: For 25% of patients, an EPD was used during CAS, and for 75% it was not. Of the patients undergoing CAS, the prevalences of hypertension, diabetes mellitus, coronary artery disease, and cigarette smoking were 81%, 37%, 39% and 43%, respectively. In total, of the patients included 52% were symptomatic and 48% were asymptomatic. The mortality rate reduced from 2% in the no-EPD subgroup to 1% in the EPD subgroup. The occurrence of all other complications was also reportedly higher in patients who did not receive an EPD, including major stroke and myocardial infarction, except for minor events, which were reported to be almost the same in both subgroups.Conclusions: We found that the use of an EPD can help reduce the occurrence of thromboembolic complications of CAS, including myocardial infarction, major stroke, and death. Altogether, our results suggest that the benefits of using an EPD during CAS outweigh its risks.

Cerebrovascular Events in Patients Undergoing Transcatheter Aortic Valve Replacement: A Review.

Cerebrovascular events (CVEs) are a dreaded complication of transcatheter aortic valve replacement (TAVR). They are associated with significant mortality, morbidity, and reduced quality of life and impose a significant burden to health care systems. Although the rates of clinical stroke have reduced since the advent of TAVR, it remains an important complication, particularly as TAVR is increasingly utilized. CVE may occur at the time of the TAVR, as a direct consequence of the procedure, or may occur later, related to thrombosis of the prosthetic valve, atrial fibrillation, and other comorbidities. Imaging of the brain has revealed a high prevalence of subclinical cerebral infarcts (68%-98%) associated with the TAVR procedure. Although their clinical significance has not been fully established, clinically evident CVE ranges between 3% and 5% in patients considered at high operative risk to between 1% and 3% in low operative risk patients. Periprocedural CVEs are largely the result of embolization of the thrombus and tissue derived from the valve, vasculature, or myocardium. Cerebral embolic protection devices have been studied in multiple trials, with some evidence supporting a reduction in new cerebral lesion volume, number, and potentially disabling strokes. However, thus far, there is no robust evidence that they reduce the overall stroke rate. The number and severity of comorbidities, in particular, new-onset atrial fibrillation, are associated with CVEs. Valve thrombosis diagnosed using computed tomography as areas of hypoattenuated leaflet thickening has been identified in 10% to 15% of patients. This is a dynamic process associated with an increase in CVEs, but that resolves with anticoagulation or sometimes without it. Routine use of anticoagulation compared with a single antiplatelet agent is associated with an increased risk of bleeding, without any additional alleviation in risk of thromboembolism. Future studies to improve risk stratification could facilitate the tailoring of preventive therapies to patients at high risk of CVE, who stand to gain the most benefit.

Cerebral Embolic Protection: Is There a Benefit for Left Atrial and Mitral Valve Procedures?

This review aims to highlight the current evidence on the use of cerebral embolic protection devices (CEPD) in left atrial and transcatheter mitral valve procedures. It also aims to summarize the antithrombotic management of patients undergoing such procedures. Ischemic stroke is one of the most devastating complications of structural heart procedures. The manifestation of periprocedural stroke can range from asymptomatic and detectable only through brain imaging to major stroke with neurological deficits. CEP devices were initially developed to mitigate the risk of stroke associated with transcatheter aortic valve replacement (TAVR). However, the efficacy of such devices during different cardiac interventions is yet to be fully demonstrated, especially in left atrial appendage closure (LAAO), and mitral valve interventions. Few studies demonstrated that the risk of periprocedural strokes after LAAO and mitral valve interventions is not negligible and is highest during the periprocedural period and then falls. The majority of patients undergoing those procedures have cerebral ischemic injuries detected on diffusion-weighted magnetic resonance imaging (DW-MRI). Moreover, a reasonable number of those patients had debris embolization on the filters of the CEPD. Pharmacological therapy with antithrombotic agents before, during, or after structural heart interventions is crucial and should be tailored to each patient's risk of bleeding and ischemia. Close monitoring that includes a full neurological assessment and frequent follow-up visits with cardiac echocardiography are important. The risk of periprocedural stroke in left atrial and transcatheter mitral valve procedures is not negligible. Pharmacological therapy with antithrombotic agents before, during, or after structural heart interventions is important to mitigate the risk of stroke, especially the long-term risk. More prospective studies are needed to assess the efficacy of CEPD in such procedures.

Successful Percutaneous Rescue Treatment of Acute Carotid Stent Thrombosis Utilizing a Modified Embolic Protection Device.

Acute Carotid Stent Thrombosis (ACST) is a rare complication of Carotid Artery Stenting (CAS) with a potentially fatal outcome. We report a case of ACST occurring five minutes after the end of a successful CAS procedure that was promptly treated by carotid stent-in-stent implantation using a new percutaneous strategy based on the creation of a modified embolic protection device. Following the procedure, we did not observe brain lesions suggestive of acute cerebral ischemic events at the CT scan performed at 48 hours, as well as no neurological deficits in the following days.

Safety and efficacy of coated flow diverters in the treatment of cerebral aneurysms during single antiplatelet therapy: A multicenter study.

This multicenter study evaluates the safety and efficacy of coated flow diverters (cFDs) for the treatment of cerebral aneurysms under single antiplatelet therapy (SAPT). This is a retrospective, observational study of 41 patients (median age: 58 years) with 41 aneurysms (median size: 7 mm, 29 [71%] saccular, 9 [22%] ruptured) treated with cFDs at four neurovascular centers between 2020 and 2023. Scheduled cases received continuous SAPT starting seven days before the procedure. Emergency cases were treated with tirofiban followed by SAPT loading. The safety endpoint was ischemic complications occurring during the procedure and within four months of clinical follow-up. The Pipeline Vantage or Flex Shield was used in 26 (63%) procedures, the FRED X in 12 (29%), the p48/64 Hydrophilic Polymer Coating in 2 (5%), and the Derivo Embolization Device 2heal in 1 (2%). Single antiplatelet therapy consisted of prasugrel in 27 (66%) patients, ticagrelor in 9 (22%), and ASA in 5 (12%). There were 2 (5%) early ischemic complications (one minor stroke and one transient ischemic attack). There were no late ischemic complications in the four-month follow-up of 35 patients. The six dropouts included four nontreatment-related deaths after subarachnoid hemorrhage and two patients with a poor outcome after subarachnoid hemorrhage. Complete and favorable occlusion rates (median: 7 months) were 75% (27/36) and 89% (32/36), respectively. Coated flow diverter implantation in the setting of SAPT was safe and effective and warrants confirmation in a prospective comparative trial.

Multicenter Experience with the Pipeline Flex and Vantage with Shield Technology for Intracranial Aneurysm Treatment.

The Pipeline Embolization Device is a safe and effective treatment option for intracranial aneurysms. The newer Pipeline generations have received structural refinements and a surface modification to improve deliverability, procedural safety, and angiographic outcomes. This multicenter study evaluated the clinical safety and efficacy of the 2 surface-modified Pipeline iterations, Pipeline Vantage and Pipeline Flex with Shield Technology (PFS). Consecutive patients treated between 2017 and 2023 were retrospectively reviewed for aneurysm characteristics, procedural details, complications, and angiographic outcomes. The safety end point was the rate of procedural and postprocedural major neurologic events occurring during the hospital stay. The efficacy end point was the rate of complete occlusion at last follow-up. One hundred forty-one patients underwent 112 Pipeline Vantage procedures and 32 PFS procedures for 147 aneurysms with a mean size of 8.0 (SD, 5.9) mm (11% ruptured, 16% posterior circulation, 18% nonsaccular morphology). All procedures were technically successful with a mean of 1.2 devices implanted. Balloon angioplasty was required in 20/144 (13.9%) procedures. Major neurologic adverse events occurred in 6/144 (4.2%) procedures (all ischemic stroke), resulting in death in 2 (1.4%) patients. There were no hemorrhagic complications. At a mean of 11 months, complete occlusion was achieved in 85/112 (75.9%) aneurysms, 15/112 (13.4%) had an entry remnant, and 12/112 (10.7%) had an aneurysm remnant. The results demonstrate high feasibility, procedural safety, and efficacy of the surface-modified Pipeline flow diverters.

Role of Embolic Protection in Percutaneous Coronary Intervention without Saphenous Venous graft lesions in ST-elevation myocardial infarction - a systematic review and meta-analysis.

Embolic protection devices are catheter-based devices that can be used to capture atherosclerotic remnants released during percutaneous coronary intervention (PCI). We aim to study the efficacy and safety of EPDs in PCIs without saphenous vein grafts (SVG) in ST-elevation myocardial infarction(STEMI). 3 electronic databases of MEDLINE, Web of Science, and Embase were searched from inception to Apr 10, 2024, to identify relevant randomized controlled trials (RCTs) that compared outcomes of patients subjected to EPD during PCI with control group where EPDs were not utilized. The primary outcome was 30-day all-cause mortality. Secondary outcomes were major adverse cardiovascular and cerebrovascular events (MACCE) at 30 days, post-PCI Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow attainment, ST-segment resolution at 90 minutes post-procedure and post-procedure angiographically detectable signs of distal embolization. The effect estimates of outcomes were assessed using risk ratio (RR) with a 95% confidence interval (CI). Random-effects meta-analysis was conducted using the restricted maximum likelihood method given the inter-study variance was inevitable. We included 3 RCTs enrolling 741 patients (age 61.6 ± 12.15 years, 22% females) undergoing PCI without SVG lesions. As opposed to the control group, the use of EPD did not yield a significant effect on all-cause mortality (RR, 0.76; 95% CI, 0.31-1.86; I2 = 0%), MACCE (RR, 0.66; 95% CI, 0.34-1.27; I2 = 0%), post-PCI TIMI 3 flow (RR, 1.18; 95% CI, 0.86-1.62; I2 = 77%) and ST segment resolution at 90 minutes post-procedure (RR, 1.05; 95% CI, 0.90-1.22; I2 = 0%). However, EPD significantly decreased angiographically detectable signs of distal embolization (RR, 0.60; 95% CI, 0.36 to 0.99; I2 = 0%). EPD significantly reduced angiographically detectable signs of distal embolization in PCI without SVG lesions in STEMI, though there were no clinical signs of improved flow or mortality. Further trials are necessary to thoroughly evaluate the potential benefits and requirements of EPD usage in such procedures.

Braids and beyond: a comprehensive study on pipeline device braid stability from PREMIER data

BackgroundThe pipeline embolization device (PED) has been increasingly used to treat brain aneurysms; however, concerns have been raised about braid stability with newer drawn filled tubing technology devices.ObjectiveTo evaluate braid...

Efficacy of Sentinel Cerebral Embolic Protection Device in Transcatheter Aortic Valve Replacement: A Meta-Analysis of Randomized Controlled Trials and Propensity Score-Matched Studies.

Transcatheter aortic valve replacement (TAVR) is frequently associated with stroke due to debris embolization. Although the risk of stroke with newer-generation devices is lower, stroke still represents a significant cause of mortality and morbidity post-TAVR. The Sentinel cerebral embolic protection device (CEPD) is a dual-embolic filter device designed to capture debris dislodged during TAVR. A systematic literature search was performed on the major bibliographic databases to retrieve studies that compared TAVR with and without Sentinel CEPD. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the DerSimonian-Laird random-effects model, with a P value of <0.05 considered statistically significant. This meta-analysis included 6 studies with 25,130 patients undergoing TAVR (12,608: Sentinel CEPD; 12,522: without Sentinel CEPD). The use of the Sentinel CEPD in TAVR was associated with a statistically significant lower risk of acute kidney injury (OR: 0.89; 95% CI: 0.81-0.97; P = 0.01]. The use of Sentinel CEPD in TAVR was associated with a statistically insignificant trend toward a reduction in stroke (OR: 0.80; 95% CI: 0.58-1.10; P = 0.18), all-cause mortality (OR: 0.74; 95% CI: 0.51-1.07; P = 0.11), and major vascular complications (OR: 0.74; 95% CI: 0.46-1.19; P = 0.21). The use of Sentinel CEPD in patients undergoing TAVR does not lead to a statistically significant reduction in stroke, all-cause mortality, or major vascular complications; however, the risk of acute kidney injury is lower. Further randomized studies are warranted to confirm these findings.

Treatment of Acute Iatrogenic Cerebrovascular Injury Using Flow Diverter Stents

BACKGROUND AND OBJECTIVES: Iatrogenic cerebrovascular injury can cause intracranial hemorrhage and pseudoaneurysm formation, putting patients at high risk for postoperative bleeding. No consensus for management exists. This study describes endovascular treatment of these acute injuries with flow diverter stents. METHODS: Electronic medical records were retrospectively reviewed for injury type and etiology, timing of diagnosis, and endovascular management, including antiplatelet regimens, embolization results, and clinical outcome. RESULTS: Six patients were included. Three suffered an injury to the internal carotid artery, 1 suffered an injury to the left anterior cerebral artery, 1 suffered an injury to the right posterior cerebral artery, and 1 suffered an injury to the basilar artery. Four of the 6 injuries occurred during attempted tumor resection, 1 occurred during cerebrospinal fluid leak repair, and 1 occurred during an ophthalmic artery aneurysm clipping. All injuries resulted in pseudoaneurysm formation. Four were immediately detected on angiography; 2 were initially negative on imaging. Five were treated with a pipeline embolization device, and 1 was treated with a Silk Vista Baby. Two were treated with 2 pipeline embolization devices telescopically overlapped across the pseudoaneurysm. All devices deployed successfully. No pseudoaneurysm recurrence or rebleeding occurred. No parent artery occlusion or stenosis was observed, and complete pseudoaneurysm occlusion was observed in 4 patients (in 2 patients, follow-up imaging could not be obtained). CONCLUSION: With proper antiplatelet regimens, flow diverter stents can be used safely to successfully treat complex acute iatrogenic injuries. Early repeat angiogram is needed when immediate postinjury imaging does not discover the point of vessel injury.