Restoring Access in a Thrombosed Hemodialysis Reliable Outflow Graft Using the InThrill Thrombectomy System

Arteriovenous grafts (AVGs) provide vascular access for hemodialysis in patients with end-stage renal disease (ESRD). However, vascular access thrombosis often occurs, requiring frequent reinterventions to maintain access patency. This report describes the successful use of the InThrill Thrombectomy System (Irvine, CA: Inari Medical) for macerating and removing thrombus from an occluded and heavily thrombosed AVG. A 47-year-old male was sent to our institute for a thrombosed right upper extremity arteriovenous access with a HeRO graft (South Jordan, UT: Merit Medical). The patient underwent interventions for the thrombosis of the same AVG two weeks prior using an Aspirex catheter (Franklin Lakes, NJ: BD Medical), and again two days prior with a Fogarty balloon catheter (Irvine, CA: Edwards Lifesciences). The patient presented with a recurrent completely occluded AVG. Using the InThrill Thrombectomy System and balloon angioplasty, the stenosis was reduced to less than 20%, resulting in brisk flow. The patient tolerated the procedure well without complication and recovered in the holding area with no acute distress. He was discharged the same day on anticoagulation therapy. This study highlights the successful use of the InThrill Thrombectomy System for the treatment of thrombosed AVG in a hemodialysis-dependent ESRD patient. The device was easy to use and efficient. Device and procedure times are unparalleled when compared with thrombolytic-based procedures. The patient's AVG remained patent at a 14-day follow-up.

Rapidly Progressive Contralateral Internal Carotid Artery Stenosis After COVID-19 Infection in a Down Syndrome Patient With Unilateral Moyamoya Arteriopathy

Moyamoya arteriopathy is a condition where chronic, progressive stenosis of large intracranial arteries, primarily of the anterior circulation, results in ischemia and the growth of small, abnormal collateral vessels. There is increasing evidence that infectious pathologies, such as COVID-19, may serve as a sort of trigger, or "second hit," for the development of moyamoya arteriopathy. In this article, we present the case of a 13-year-old female with Down syndrome and unilateral moyamoya arteriopathy who developed contralateral internal carotid artery (ICA) dissection and thrombus in the setting of a positive COVID-19 test and subsequently developed rapidly progressive contralateral ICA and bilateral anterior cerebral artery (ACA) moyamoya-like stenosis. The rapidly progressive contralateral ICA and bilateral ACA moyamoya-like stenosis are likely multifactorial in nature. The contralateral ICA may have had a predisposition for injury and stenosis due to the preexisting moyamoya arteriopathy, making stenosis more likely after COVID-19-induced vascular inflammation and injury as well as after a possible thrombectomy-associated injury. Based on this presentation, patients with moyamoya arteriopathy may be at risk for rapid progression of their moyamoya pathology when exposed to catalysts, including infection, such as COVID-19, and vascular injury, such as thrombectomy-induced injury. In these circumstances, high suspicion and close monitoring are essential for addressing ischemia related to the stenosis before permanent injury.

A Case Report on May-Thurner Syndrome: Beyond the Usual Suspects

May-Thurner syndrome (MTS), also known as iliocaval venous compression syndrome, is a vascular condition characterized by extrinsic venous compression within the iliocaval territory. While traditionally considered a condition predominantly affecting women, this case report presents an atypical presentation in a middle-aged male patient. The patient initially presented with left lower extremity pain and swelling, which was attributed to deep venous thrombosis (DVT) in the left calf and femoral vein. Despite anticoagulation therapy, his symptoms persisted, leading to further diagnostic evaluation and the identification of MTS. This report highlights the clinical presentation, diagnostic challenges, and successful management of MTS in a male patient. Endovascular interventions, including balloon dilation and stent placement, were employed to address refractory stenosis and thrombus burden. The case emphasizes the importance of considering MTS as a potential diagnosis in patients with unexplained lower limb symptoms, irrespective of traditional risk factors or gender. Early identification and appropriate interventions can lead to symptom relief, obstruction resolution, and improved long-term outcomes for patients with MTS. This case underscores the need for heightened clinician awareness regarding MTS and its potential impact on patient care.

Mechanical Thrombectomy for a Clot in Transit With Adherence to the Tricuspid Valve

This case report investigates the management of a clot in transit (CIT), a rare but possibly life-threatening condition discovered in a small percentage of pulmonary embolism (PE) cases. CITs are thrombi lodged within the right-side heart chambers or the major veins, and there are currently no universal guidelines for their management though the literature has shown reduced mortality with reperfusion therapy compared to anticoagulation alone. In this case, a 96-year-old male who presented with a submassive PE was initially stabilized with anticoagulation and was then discovered to have a CIT with adherence to the tricuspid valve. The patient underwent a successful mechanical thrombectomy using the Inari FlowTriever (Inari Medical, Irvine, CA), an FDA-approved device for CIT removal. Overall, this manuscript supports this percutaneous intervention in intermediate to high-risk PE patients with concomitant CIT, offering an alternative to thrombolysis and cardiothoracic surgery, which carry their own risks. Furthermore, the unique characteristic of the CIT in this patient suggests a potential for further investigation into the diversity of CIT morphology and its significance.

The Efficacy and Safety of Mechanical Thrombectomy in Posterior Circulation Large Vessel Occlusion as Compared to Anterior Circulation Large Vessel Occlusion: A Systematic Review

Mechanical thrombectomy (MT) has been established as a standard of care for patients with stroke due to anterior circulation large vessel occlusion (AC-LVO). Due to a lack of robust evidence for the effectiveness of mechanical thrombectomy, intravenous thrombolysis (IVT) is still the only approved first-line acute reperfusion strategy for posterior circulation large vessel occlusion (PC-LVO). This systematic review analyzes and reports on the effectiveness and safety of MT in PC-LVO. A literature review was performed to identify all studies of patients with acute ischemic stroke due to PC-LVO who underwent MT with second-generation devices (stent retrievers and/or aspiration devices) that were reported between January 2017 and January 2023. The primary outcome was functional independence at 90 days, defined as a modified Rankin (mRS) score of ≤2. Secondary outcomes were successful recanalization (modified treatment in cerebral infarction score (mTICI) 2b/3), symptomatic intracerebral hemorrhage (sICH), and mortality at 90 days post-procedure. We looked at 13 studies with a total of 30,407 participants in four meta-analyses and 5951 participants in nine observational studies. In most studies, patients in the PC-LVO group were male and younger than the AC-LVO group. Higher baseline National Institutes of Health Stroke Scale (NIHSS) score, lower rates of IVT, longer onset-to-groin puncture time, lower likelihood of sICH, higher 90-day mortality rates, and higher futile recanalization rates were frequently observed in the PC-LVO group with a large discrepancy in the likelihood of functional independence at 90 days with majority studies showing comparable rates. Hence, in patients with acute ischemic stroke caused by the PC-LVO, successful reperfusion can be achieved via MT, though at the cost of higher mortality rates. Such futile recanalization can be avoided with the refinement of procedures through technical improvements, skills training, and recognition of reliable predictors associated with it, which might help increase the efficacy of MT in PC-LVO. Additionally, future large-scale RCTs comparing patient selection and interventional strategies to avoid futile interventions are also needed.

SARS-CoV-2: Current Tools to Fight COVID-19 ST-Elevation Myocardial Infarction

The capacity of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to wreak havoc on the inflammatory and coagulation pathways via the cytokine storm has led to over 6.3 million fatalities globally. Based on recent data, the mechanism predominately involves the formation of microvascular thrombosis when pertaining to cardiovascular disease. However, a subset of coronavirus disease-2019 (COVID-19)-positive patients present emergently with acute ST-elevation myocardial infarction (STEMI) are found to have severe epicardial thrombosis which is refractory to traditional coronary revascularization. We have noted mortality in these patients presenting to our facility to be as high as 90% and all angiographically confirmed to have thrombus which was refractory to traditional therapy. We present a case series of COVID-19-positive patients presenting with STEMI found to have epicardial thrombus who were treated with different traditional STEMI therapies but with fatal outcomes. Other possible techniques including mechanical thrombectomy, optimizing traditional and nontraditional anticoagulation therapy with the use of early hemodynamic support may prove more efficacious to destroy thrombus and potentially improve mortality.

Acute Myocardial Infarction in a Young Male With COVID-19 Infection

Coronavirus disease 2019 (COVID-19) infection is a global health crisis resulting in significant morbidity and mortality. The presentation of COVID-19 infection is variable, ranging from an asymptomatic carrier state to multi-organ failure. While cases of COVID-related myocarditis and myocardial dysfunction are well reported, only a few cases of coronary artery thrombosis resulting in myocardial infarction are noted on literature review. However, the previously reported cases were in patients with high risk for coronary artery disease. We hereby report a case of a young man with no significant past medical history or cardiovascular risk factors who presented with severe chest pain and was diagnosed with acute myocardial infarction in the setting of COVID-19 infection requiring intervention. We want to report this case to improve awareness in the community about COVID-related arterial thrombosis and have a high index of suspicion for this regardless of the person's risk factors for cardiovascular diseases.

Mechanical Thrombectomy via Transradial Approach for Posterior Circulation Stroke: A Systematic Review and Meta-Analysis

Mechanical thrombectomy for acute ischemic stroke (AIS) is traditionally performed via transfemoral access. While the majority of AISs are due to anterior circulation large vessel occlusions (AC-LVO), we performed a systematic review and meta-analysis to examine the feasibility of and outcomes following a transradial artery access for posterior circulation large vessel occlusion (PC-LVO) strokes. A systematic literature review of the English language literature was conducted using PubMed, MEDLINE, and Embase as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Outcomes of interest included 90-day modified Rankin scale (mRS) 0-2, puncture to recanalization time, and thrombolysis in cerebral infarction (TICI) scores 2b/3 and 3. We calculated pooled event rates and their corresponding 95% confidence intervals (CI) for all outcomes. We included seven studies with 68 patients in our analysis. All patients underwent mechanical thrombectomy via transradial artery access for AIS due to PC-LVO. The pooled meantime of puncture to recanalization was 29.19 (95% CI=24.05 to 35.42) minutes. Successful recanalization (TICI2b/3) was achieved in 98.69% (95% CI=93.50 to 100) of patients and complete recanalization (TICI 3) in 52.16% (95% CI=34.18 to 79.60) of the patients. Overall, 56.84% (95% CI=41.26 to 78.30) of patients achieved mRS 0-2. Transradial artery access for mechanical thrombectomy for PC-LVO stroke displays early promise and feasibility, particularly regarding very high rates of successful recanalization and low puncture to recanalization time.

Acute Thromboembolic Ischemic Stroke From Complex Aortic Arch Plaque

Atherosclerosis is a systemic pathologic process, may involve aorta and is important cause of systemic embolization. The risk of embolism is increased for mobile and complex aortic plaques that are >4 mm thick. The most common manifestations are stroke, transient ischemic attack (TIA) and peripheral embolization. Imaging modalities used include transesophageal echocardiogram (TEE), CT angiography and magnetic resonance angiography (MRA). The mainstays of medical treatment are antiplatelets and statin. The role of anticoagulation is reserved for plaques with thrombotic component.

There were two patients who presented with large acute ischemic stroke with high grade, floating aortic arch thrombus and complex aortic arch plaques. In one of cases, after 10-day follow-up CT aortic angiography showed completely resolved thrombus after being treated with IV tissue plasminogen activator (TPA) followed by low molecular weight heparin (LMWH). The risk of embolism depends on size of aortic plaques and mobility. TEE is modality of choice for thoracic aortic plaques. Aortic plaques >4 mm are independent predictors of recurrent ischemic stroke. There are limited data available for off-label use of intravenous thrombolysis and mechanical thrombectomy (MT) in presence of aortic arch thrombus in acute ischemic strokes. These two case reports help in recognition of aortic arch complex plaques as independent risk factor for recurrent stroke. The right patients may consider about the use of intravenous alteplase and MT performed via trans-brachial access after excluding aortic dissection and aneurysm. In future, multicenter, randomized controlled trials will be required for safety of IV TPA and MT.