In Vitro Blood Clot Formation and Dissolution for Testing New Stroke-Treatment Devices.

Strokes are among the leading causes of death worldwide. Ischemic stroke, due to plaque or other buildup blocking blood flow to the brain, is the most common type. Although ischemic stroke is treatable, current methods have severe shortcomings with high mortality rates. Clot retrieval devices, for example, can result in physically damaged vessels and death. This study aims to create blood clots that are representative of those found in vivo and demonstrate a new method of removing them. Static blood clots were formed using a 9:1 ratio of whole sheep blood and 2.45% calcium chloride solution. This mixture was heated in a water bath at 37 °C for approximately one hour until solidified. Following clot solidification, human plasmin was introduced by various methods, including soaking, injection, and membrane perfusion, and the resulting dissolution percentages were determined. Different clot types, representative of the wide range found physiologically, were also manufactured and their dissolution characteristics evaluated. A method to reproducibly create blood clots, characteristic of those found in vivo, is essential for the production of stroke retrieval devices that can efficiently and effectively remove clots from patients with low mortality rates and little/no damage to the surrounding vessels.

Combinatorial treatment for unresectable unicentric Castleman disease.

Unresectable, symptomatic unicentric Castleman disease (UCD) can represent a formidable therapeutic challenge. UCD masses are often highly vascularized offering the opportunity for therapeutic embolization. Herein, we report on 6 patients in which therapeutic embolization was combined with other medical interventions including surgery (n = 3), rituximab (n = 6), cryoablation (n = 2), and chemotherapy (n = 3). Five patients had significant tumor volume reductions (median: 83.2%; range: 76.7-100). All five responding patients had resolution of symptomatology. There were no serious complications in the patients who received embolization and proceeded to surgery. In conclusion, effective disease and symptom control can be obtained in patients with symptomatic, unresectable UCD by combining different therapeutic interventions.

Use of "super-glue" to seal a perforation during chronic total occlusion coronary intervention and the potential to "unglue" it.

Coronary perforation remains a dreaded complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We present a case of successful CTO recanalization complicated by a perforation treated by n-butyl-cyanoacrylate (medical "super-glue"). We also present an in vitro experiment showing that a glue plug in a plastic tube can acutely be passed by a low tip load guide wire and undergo balloon angioplasty recreating a lumen. These results suggest that n-butyl-cyanoacrylate glue may be an alternative for treating perforation during CTO PCI with the possibility of recanalizing the vessel through the glue plug at a later time.

Lightly Embalmed Cadavers as a Training Tool for Ultrasound-Guided Procedures Commonly Used in Interventional Radiology.

RATIONALE AND OBJECTIVES: Competency in ultrasound (US) imaging and US-guided procedures is often difficult for medical students and residents to master. The use of simulation training has been strongly encouraged but the quality of phantom models available for US-guided procedures is limited. As a feasible alternative, we describe the innovative use of a lightly embalmed cadaver for realistic practice of common interventional radiology (IR) procedures prior to direct patient care. MATERIALS AND METHODS: Lightly embalmed cadavers were positioned as patients would be in the IR suite: supine, prone, and erect seated position. Lidocaine was injected and visualized under standard percutaneous techniques and sonographic guidance was used to simulate common US-guided procedures performed in IR including liver biopsy, kidney biopsy, thoracentesis, and vascular access. RESULTS: The ability to position cadavers was a key factor that allowed entire procedures to be simulated. Medical students with very limited exposure to US imaging and diagnostic radiology residents with minimal exposure to US imaging successfully completed common US-guided procedures. Arterial and venous vascular access was obtained. Wires were passed and catheters easily placed via both access sites. The texture of the tissue layers provided realistic feedback for the trainees as they advanced the needle or dilated the tissues. Images from each simulated procedure resembled images expected in a living patient. CONCLUSION: Lightly embalmed cadavers are an innovative and feasible tool to simulate common IR US-guided procedures in a realistic fashion for deliberate practice in advance of first-attempt encounters with patients.

Use of a mechanical thrombectomy device to treat early hepatic artery thrombosis after orthotopic liver transplant.

Hepatic artery thrombosis (HAT) is a major cause of morbidity and mortality after orthotopic liver transplantation, occurring in 5% of cases (Piardi et al, 2016). HAT is the second main cause of graft loss after primary nonfunction, the leading cause of graft failure in the immediate postoperative period (<1 month), and is associated with a mortality rate of up to 60% without intervention (Piardi et al, 2016; Pareja et al., 2010; Crossin et al., 2003). Although retransplantation is the preferred therapy, the limited availability of donor organs can necessitate urgent, alternative treatment. These patients present physicians with an often-severe clinical picture, which requires consideration of endovascular approaches as opposed to the more traditional, invasive surgical interventions. The following case study presents a novel mechanical therapy that uses an endovascular approach for revascularization-a stent retriever device.

New generation aspiration catheter: Feasibility in the treatment of pulmonary embolism.

AIM: To report our preliminary experience with a new generation aspiration catheter in the treatment of symptomatic pulmonary embolism (PE). METHODS: A retrospective database search for pulmonary artery embolectomy since introduction of the Pronto .035" and XL extraction catheter (Vascular Solutions, Minneapolis, MN) at our institution in 10/2009 was performed. Ten consecutive patients were identified in which the Pronto .035" or XL catheter was used between 01/2010 and 03/2013. All patients were referred for catheter based embolectomy due to contraindications to systemic lysis, or for being in such a critical clinical condition that immediate percutaneous treatment deemed warranted. The computed tomography (CT) right to left heart ratio as predictor for the severity of the PE was retrospectively evaluated on standard axial views. The difference between pre- and post-procedure pulmonary pressure measures was taken to assess the procedural effect. RESULTS: Extensive PE was confirmed angiographically in all patients. Measured right- to left ventricle (RV/LV) ratios were elevated beyond one in seven of the eight available CTs. Acute procedural success defined as clinical removal of visible thrombus and improvement in mean pulmonary artery pressure was seen in all recorded patients (n = 8), the mean pulmonary pressures declined from a median (range) of 35.5 (19-46) to 23 (10-37, P = 0.008) mmHg. Neither death nor other complications occurred intra- or immediately periprocedural, yet short term mortality within 30 d was found in 6 out of 9 patients, one patient was lost in follow up. The cause of death within 30 d in the 6 patients was identified as: Circulatory failure in direct connection with the PE (n = 2), stroke, sepsis, or succumbing to malignancy in a hospice setting (n = 2). CONCLUSION: Success in thrombus removal with improved pulmonary hypertension and systemic hypotension suggests this aspiration technique to be effective. Aspiration catheters should be part of further trials.

Management of pulmonary arteriovenous malformations.

Pulmonary arteriovenous malformations are rare lesions with significant clinical complications. These lesions are commonly seen in patients with hereditary hemorrhagic telangiectasia (formerly Osler-Weber-Rendu syndrome). Interventional radiologists are a key part of the treatment team in this complex disease, and a thorough understanding of the disease process is critical to providing good patient care. In this article, the authors review the disease course and its association with hereditary hemorrhagic telangiectasia, discusses the clinical evaluation and treatment of these complex patients, and outlines complications and follow-up.