Christine Chung

Comparing the embolic potential of open and closed cell stents during carotid angioplasty and stenting

OBJECTIVE We sought to determine the effects of open (O) and closed (C) cell stents on the size and number of embolic particles generated during carotid artery stenting (CAS) and assess the impact on outcome. METHODS Embolic debris from carotid filters after CAS was analyzed using photomicroscopy and imaging software. Patient comorbidities, preoperative cerebrovascular symptoms, stent type, and outcomes (perioperative major adverse events) were examined. RESULTS Carotid filters from 173 consecutive CAS procedures (O, 125 and C, 48) were reviewed. The mean age was 70.9 ± 9.2 years; 58% were men. Mean stenosis was 88.2% ± 8.1%; 36.6% had neurological symptoms preprocedurally. There was no difference in preoperative symptoms between the two groups (O, 38.7% vs C, 31.3%; P = not significant [NS]). However, closed cell stent use was associated with higher degree of stenosis (O, 87.2% ± 8.0% vs C, 90.6% ± 7.8%; P = .01), an older age (O, 70.0 ± 8.6 years vs C, 73.4 ± 10.2 years; P = .03), and peripheral arterial disease (21.1% vs 43.5%; P = .01). A larger mean particle size was observed in patients treated with open cell stents compared to closed cell stents (O, 416.5 ± 335.7 μm vs C, 301.1 ± 251.3 μm; P = .03). There was no significant difference in the total number of particles (O, 13.8 ± 21.5 vs C, 17.6 ± 19.9; P = NS), periprocedural stroke (P = NS), and major adverse events between the two groups (P = NS). CONCLUSIONS Open cell stents are associated with a larger mean particle size compared to closed cell stents. No impact on procedural outcomes based on stent type was observed.

Endovascular Stent-Graft Repair of a Tuberculous Mycotic Aortic Aneurysm

Mycobacterium tuberculosis is a rare cause of mycotic aortic aneurysms, which have been classically treated with a combination of antimycobacterial medical therapy and open surgery. Endovascular therapy has been gaining popularity as an alternative to open surgery for mycotic aneurysms. We report a case of a tuberculous mycotic aneurysm of the descending thoracic aorta that was successfully treated with endovascular stent-graft placement with complete resolution of the pseudoaneurysm at 1 year. We also review other cases in the previously published data to identify factors that may affect the outcome of endovascular treatment of tuberculous mycotic aneurysms.

Staged hybrid open and endovascular exclusion of a symptomatic thoracoabdominal aortic aneurysm in a high-risk patient

Thoracoabdominal aortic aneurysms have a higher prevalence in the elderly, who are often poor surgical candidates. These extensive aneurysms may be lethal if left untreated. Conventional open repair has proven to be a major task, involving cardiopulmonary bypass, aortic cross-clamping and expeditious repair of an inaccessible structure involving two body cavities. Endovascular repair has become a viable option to treat isolated descending thoracic aneurysms and infrarenal abdominal aortic aneurysms. However, endovascular techniques alone have been less applicable for treating complex aortic aneurysms, including those involving visceral vessels. Therefore, a hybrid open and endovascular approach with visceral debranching has become an increasingly favorable alternative for patients with these complex conditions. We report a case in which a staged hybrid approach was used for successful exclusion of an extensive thoracoabdominal aortic aneurysm in a symptomatic, high-risk patient who would not have been an appropriate candidate for open surgical repair.

Endovascular Treatment of 2 Synchronous Extracranial Carotid Artery Aneurysms Using Stent-Assisted Coil Embolization and Double Bare-Metal Stenting.

Extracranial carotid artery aneurysms located in the cervical region in close proximity to the skull are difficult to access using open surgical methods. Endovascular treatment has emerged as an alternative option for anatomically challenging internal carotid artery aneurysms. However, data comparing various endovascular techniques including stent grafting, coil embolization, double stenting, and stent-assisted coil embolization are lacking, making it difficult to determine the optimal treatment. We present a case of a patient with 2 fusiform extracranial carotid artery aneurysms treated successfully with a combination of double stenting and stent-assisted coil embolization. We also discuss technical considerations for selecting the appropriate endovascular intervention.

Reconstruction of “unreconstructable” critical limb ischemia with hybrid techniques

This case describes the surgical repair of critical limb ischemia in a patient with diffuse multilevel peripheral arterial disease. It demonstrates the value of patient-specific approaches that employ hybrid endovascular and open surgical techniques to reconstruct blood flow in patients who are not ideal candidates for traditional revascularization. We detail a technique that combines endarterectomy, femoropopliteal bypass, angioplasty, and stenting. This case suggests that innovative hybrid approaches can be used to achieve limb salvage in some patients with multilevel peripheral vascular disease who would otherwise undergo primary amputation.

Diabetic Considerations in Cerebrovascular Disease

Diabetes is a global epidemic affecting millions of people and incurring exorbitant costs. Cerebrovascular disease is recognized as the most common long-term cause of morbidity in diabetics. Although the pathophysiology of diabetes has yet to be clearly established, diabetes is an incontestable risk factor for cerebrovascular impairment. It is responsible for a wide spectrum of disease from cognitive impairment to ischemic stroke, which is the predominant cerebrovascular manifestation of diabetes. Many risk factors for stroke prevention have been investigated. Although glycemic control has been the foundation of diabetic management, intensive glycemic control has not proven to reduce the incidence of stroke, although its benefit in preventing microvascular events, such as retinopathy, nephropathy, and peripheral neuropathy, has been observed. The modification of other risk factors, such as hypertension and dyslipidemia, has been shown to decrease the risk for cerebral infarction in this high-risk group. Additionally, advanced carotid disease is a prevalent risk factor for stroke in diabetics. The measurement of carotid intima–media thickness and serum biomarkers may identify diabetic patients with significant carotid atherosclerosis, which increases the risk for transient ischemic attacks and ischemic stroke. Therefore, multifactorial risk management in diabetic patients has proven to be the optimal method for treating diabetic patients at increased potential for developing cerebrovascular disease.

Plaque Echolucency May Play a Critical Role in Predicting Cerebral Embolization in Patients Undergoing Carotid Angioplasty and Stenting

Introduction Despite ongoing studies, the relationship of plaque echomorphology with increased risk of stroke in patients undergoing carotid angioplasty and stenting (CAS) remains elusive. The aim of this study is to examine whether carotid plaque echolucency is associated with greater plaque instability as determined by the quantification of captured embolic debris in CAS patients. Methods A total of 41 consecutive CAS patients with high-grade carotid stenosis were prospectively evaluated. B-mode images for 21 patients were available for analysis. Plaque echolucency was determined by grayscale median (GSM), a computer-assisted measure of echogenicity. Images were standardized with a GSM value of 0–5 for the vessel lumen and 185–195 for the adventitia. Echolucent (EL) plaques were defined by GSM < 25, and echogenic (EG) plaques were defined by GSM ≥ 25. Protective filters were visualized by stereomicroscopy along three perpendicular axes and quantified through video imaging software. Because of heterogeneity in particle shape, individual particle sizes were determined by greatest length. Results Mean GSM was 45.5, and 10% plaques were echolucent. Particulate debris was detected in all filters. Plaques with lower GSM were associated with a greater number of particles (EL: 33.5 ± 10.6 particles, EG: 14.0 ± 10.3 particles; p = 0.02). Echolucent plaques also demonstrated particles of greater size: maximum size (EL: 3490 ± 1954 μm, EG: 1026 ± 1186 μm; p = 0.015) and number of particles >1000 μm (EL: 3.5 ± 2.1 particles, EG: 0.7 ± 1.4 particles; p = 0.019). Conclusions Echolucent carotid plaques, as determined by GSM, may cause increased embolization of greater-sized embolic debris during CAS. Our study confirms previous findings that suggest that a GSM cut-off point of 25 may be linked with the release of more embolic debris. Therefore, increased plaque echolucency may place patients at greater risk for perioperative embolic events, making patients with such lesion characteristics more likely to experience postprocedural neurologic complications.