Magnetically Targeted Endothelial Cell Localization in Stented Vessels

ObjectivesA novel method to magnetically localize endothelial cells at the site of a stented vessel wall was developed. The application of this strategy in a large animal model is described.BackgroundLocal delivery of blood-derived endothelial cells has been shown to facilitate vascular healing in animal models. Therapeutic utilization has been limited by an inability to retain cells in the presence of blood flow. We hypothesized that a magnetized stent would facilitate local retention of superparamagnetically labeled cells.MethodsCultured porcine endothelial cells were labeled with endocytosed superparamagnetic iron oxide microspheres. A 500:1 microsphere-to-cell ratio was selected for in vivo experiments based on bromo-deoxyuridine incorporation and terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assays. Stents were magnetized and implanted in porcine coronary and femoral arteries using standard interventional equipment. Labeled endothelial cells were delivered locally during transient occlusion of blood flow.ResultsThe delivered cells were found attached to the stent struts and were also distributed within the adjacent denuded vessel wall at 24 h.ConclusionsMagnetic forces can be used to rapidly place endothelial cells at the site of a magnetized intravascular stent. The delivered cells are retained in the presence of blood flow and also spread to the adjacent injured vessel wall. Potential applications include delivering a cell-based therapeutic effect to the local vessel wall as well as downstream tissue

Clarifying the anatomy and physiology of totally anomalous systemic venous connection

The description of totally anomalous systemic venous connection is limited to case reports. In this review, we seek to clarify anatomic, physiologic, and hemodynamic aspects of this extremely rare anomaly. We also present findings of two patients in whom connection of all the systemic veins was anomalous. In the first patient, with usual atrial arrangement, all systemic veins, including the coronary sinus, were connected anomalously to the morphologically left atrium. Limited left-to-right shunt across an atrial septal defect provided the only source of blood flow to the lungs. The diagnosis was established by saline contrast echocardiography and cardiac catheterization. Extreme hypoplasia of the right ventricle precluded corrective surgery, so we performed a bidirectional Glenn operation, along with atrial septectomy. The second patient had isomerism of the left atrial appendages, which creates problems in the definition in anatomic terms since the connection of the systemic veins can never be normal anatomically when both atriums possess a morphologically left appendage. Our patient, nonetheless, had all the systemic and pulmonary veins, connected to the left-sided atrial chamber which then connected to the left ventricle, thus producing hemodynamics of totally anomalous systemic venous connection. We propose an algorithm for evaluation of this hemodynamic combination and discuss management options. We also intend to clarify the potential differences between connection and drainage, with particular attention to the arrangement of atrial appendages. Even though the hemodynamics may be comparable, in anatomic terms, both systemic and pulmonary venoatrial connection will always be anomalous with isomeric atrial appendages

Clinical and echocardiographic diagnosis, follow up and management of right-sided cardiac thrombi

Background: Right-sided cardiac masses are infrequent and have varied clinical presentation. The present study describes the clinical features, echocardiographic findings and management of 19 patients presenting with right-sided cardiac thrombi in a tertiary care center in north India. Methods: This is a retrospective, single center observational study of consecutive patients over the period January 2003–2008 admitted in our emergency intensive care unit (EICU). We identified 38 patients with right-sided cardiac masses admitted to EICU diagnosed by transthoracic echocardiography of which 19 patients had right-sided thrombus. The echocardiographic findings were reviewed by two cardiologists in all patients. Treatment was not standardized and choice of therapy was based on judgment of attending physician. Results: The mean age of patients with cardiac thrombus was 36.6 ± 11.8 years. Right atrial (n = 17) and right ventricle (n = 2) thrombi were associated with deep vein thrombosis (DVT) in 7 (36.8%) and pulmonary embolism in 3 (15%) patients. 13 (68.4%) patients appeared to have in situ mural thrombus. 12 patients were managed with oral anticoagulants, 3 patients underwent surgery and 4 patients were thrombolysed. All the survivors had a mean follow-up of 40 ± 6 months (range – 18–50 months). Conclusions: Prompt echocardiographic examination in an appropriate clinical setting facilitates faster diagnosis and management of patients with right-sided cardiac thrombi. High incidence of in situ mural thrombus and varied comorbidities predisposing to right-sided cardiac thrombi besides DVT and pulmonary embolism need to be recognized. Oral anticoagulation and thrombolysis appear to be the mainstay of treatment with surgery limited for selected patients