The Clinical Rationale for the Sentry Bioconvertible Inferior Vena Cava Filter for the Prevention of Pulmonary Embolism

The Sentry inferior vena cava (IVC) filter is designed to provide temporary protection against pulmonary embolism (PE) during transient high-risk periods and then to bioconvert after 60 days after implantation. At the time of bioconversion, the device's nitinol arms retract from the filtering position into the caval wall. Subsequently, the stable stent-like nitinol frame is endothelialized. The Sentry bioconvertible IVC filter has been evaluated in a multicenter investigational-device-exemption pivotal trial (NCT01975090) of 129 patients with documented deep vein thrombosis (DVT) or PE, or at temporary risk of developing DVT or PE, and with contraindications to anticoagulation. Successful filter conversion was observed in 95.7% of patients at 6 months (110/115) and 96.4% at 12 months (106/110). Through 12 months, there were no cases of symptomatic PE. The rationale for development of the Sentry bioconvertible device includes the following considerations: (1) the period of highest risk of PE for the vast majority of patients occurs within the first 60 days after an index event, with most of the PEs occurring in the first 30 days; (2) the design of retrievable IVC filters to support their removal after a transitory high-PE-risk period has, in practice, been associated with insecure filter dynamics and time-dependent complications including tilting, fracture, embolization, migration, and IVC perforation; (3) most retrievable IVC filters are placed for temporary protection, but for a variety of reasons they are not removed in any more than half of implanted patients, and when removal is attempted, the procedure is not always successful even with advanced techniques; and (4) analysis of Medicare hospital data suggests that payment for the retrieval procedure does not routinely compensate for expense. The Sentry device is not intended for removal after bioconversion. In initial clinical use, complications have been limited. Long-term results for the Sentry bioconvertible IVC filter are anticipated soon

Aortic dissection: Percutaneous management of ischemic complications with endovascular stents and balloon fenestration

AbstractPurpose: The purpose of this study was to evaluate endovascular stenting (EVS) and balloon fenestration (BF) of intimal flaps for the management of lower extremity, renal, and visceral ischemia in acute or chronic aortic dissection.Methods: Twenty-two patients (16 male, 6 female) with a median age of 53 years (range 35 to 77 years) underwent percutaneous treatment for peripheral ischemic complications of 12 type A (five acute, seven chronic) and 10 type B (nine acute, one chronic) aortic dissections.Results: Ten patients had leg ischemia, 13 had renal ischemia, and 6 had visceral ischemia. Sixteen patients were treated with EVS including 11 with renal, 6 with lower extremity, 2 with superior mesenteric artery, and 2 with aortic stents. Three patients had BF of the intimal flap, and three had BF in combination with EVS. Revascularization with clinical success was achieved in all 22 patients. Two patients died 3 days and 13.4 months after the procedure was performed, respectively. Of the remaining 20 patients, 1 is lost to follow-up, and 19 have persistent relief of clinical symptoms. Mean follow-up time is 13.7 months (range 1.1 to 46.5 months). One case was complicated by guidewire-induced perinephric hematoma.Conclusion: EVS and BF provide a safe and effective percutaneous method for managing peripheral ischemic complications of aortic dissection. (J VASC SURG 1996;23:241-53.

High-efficiency endovascular gene delivery via therapeutic ultrasound

AbstractOBJECTIVESWe studied enhancement of local gene delivery to the arterial wall by using an endovascular catheter ultrasound (US).BACKGROUNDUltrasound exposure is standard for enhancement of in vitro gene delivery. We postulate that in vivo endovascular applications can be safely developed.METHODSWe used a rabbit model of arterial mechanical overdilation injury. After arterial overdilation, US catheters were introduced in bilateral rabbit femoral arteries and perfused with plasmid- or adenovirus-expressing blue fluorescent protein (BFP) or phosphate buffered saline. One side received endovascular US (2 MHz, 50 W/cm2, 16 min), and the contralateral artery did not.RESULTSRelative to controls, US exposure enhanced BFP expression measured via fluorescence 12-fold for plasmid (1,502.1 ± 927.3 vs. 18,053.9 ± 11,612 μm2, p < 0.05) and 19-fold for adenovirus (877.1 ± 577.7 vs. 17,213.15 ± 3,892 μm2, p < 0.05) while increasing cell death for the adenovirus group only (26 ± 5.78% vs. 13 ± 2.55%, p < 0.012).CONCLUSIONSEndovascular US enhanced vascular gene delivery and increased the efficiency of nonviral platforms to levels previously attained only by adenoviral strategies

One-Year Analysis of the Prospective Multicenter SENTRY Clinical Trial: Safety and Effectiveness of the Novate Sentry Bioconvertible Inferior Vena Cava Filter

Purpose To prospectively assess the Sentry bioconvertible inferior vena cava (IVC) filter in patients requiring temporary protection against pulmonary embolism (PE). Materials and Methods At 23 sites, 129 patients with documented deep vein thrombosis (DVT) or PE, or at temporary risk of developing DVT or PE, unable to use anticoagulation were enrolled. The primary end point was clinical success, including successful filter deployment, freedom from new symptomatic PE through 60 days before filter bioconversion, and 6-month freedom from filter-related complications. Patients were monitored by means of radiography, computerized tomography (CT), and CT venography to assess filtering configuration through 60 days, filter bioconversion, and incidence of PE and filter-related complications through 12 months. Results Clinical success was achieved in 111 of 114 evaluable patients (97.4%, 95% confidence interval [CI] 92.5%–99.1%). The rate of freedom from new symptomatic PE through 60 days was 100% (n = 129, 95% CI 97.1%–100.0%), and there were no cases of PE through 12 months for either therapeutic or prophylactic indications. Two patients (1.6%) developed symptomatic caval thrombosis during the first month; neither experienced recurrence after successful interventions. There was no filter tilting, migration, embolization, fracture, or caval perforation by the filter, and no filter-related death through 12 months. Filter bioconversion was successful for 95.7% (110/115) at 6 months and for 96.4% (106/110) at 12 months. Conclusions The Sentry IVC filter provided safe and effective protection against PE, with a high rate of intended bioconversion and a low rate of device-related complications, through 12 months of imaging-intense follow-up

Future of IR: Emerging Techniques, Looking to the Future…and Learning from the Past

Innovation has been the cornerstone of interventional radiology since the early years of the founders, with a multitude of new therapeutic approaches developed over the last 50 years. What is the future holding for us? This article presents an overview of the in-coming developments that are catching on at this moment, particularly focusing on three items: the new applications of existing techniques, particularly embolotherapy and interventional oncology; the cutting-edge devices; the imaging technologies at the forefront of the image-guidance. Besides this, clinical vision and patient relation remain crucial for the future of the discipline

Standard of Practice for the Endovascular Treatment of Thoracic Aortic Aneurysms and Type B Dissections

Thoracic endovascular aortic repair (TEVAR) represents a minimally invasive technique alternative to conventional open surgical reconstruction for the treatment of thoracic aortic pathologies. Rapid advances in endovascular technology and procedural breakthroughs have contributed to a dramatic transformation of the entire field of thoracic aortic surgery. TEVAR procedures can be challenging and, at times, extraordinarily difficult. They require seasoned endovascular experience and refined skills. Of all endovascular procedures, meticulous assessment of anatomy and preoperative procedure planning are absolutely paramount to produce optimal outcomes. These guidelines are intended for use in quality-improvement programs that assess the standard of care expected from all physicians who perform TEVAR procedures

Thoracic aortic geometry correlates with endograft bird-beaking severity

Objective: Aortic geometry has been shown to influence the development of endograft malapposition (bird-beaking) in thoracic endovascular aortic repair (TEVAR), but the extent of this relationship lacks clarity. The aim of this study was to develop a reproducible method of measuring bird-beak severity and to investigate preoperative geometry associated with bird-beaking. Methods: The study retrospectively analyzed 20 patients with thoracic aortic aneurysms or type B dissections treated with TEVAR. Computed tomography scans were used to construct three-dimensional geometric models of the preoperative and postoperative aorta and endograft. Postoperative bird-beaking was quantified with length, height, and angle; categorized into a bird-beak group (BBG; n = 10) and no bird-beak group (NBBG; n = 10) using bird-beak height ≥5 mm as a threshold; and correlated to preoperative metrics including aortic cross-sectional area, inner curvature, diameter, and inner curvature 7 diameter as well as graft diameter and oversizing at the proximal landing zone. Results: Aortic area (1002 \ub1 118 mm2 vs 834 \ub1 248 mm2), inner curvature (0.040 \ub1 0.014 mm−1 vs 0.031 \ub1 0.012 mm−1), and diameter (35.7 \ub1 2.1 mm vs 32.2 \ub1 4.9 mm) were not significantly different between BBG and NBBG; however, inner curvature 7 diameter was significantly higher in BBG (1.4 \ub1 0.5 vs 1.0 \ub1 0.3; P =.030). Inner curvature and curvature 7 diameter were significantly correlated with bird-beak height (R = 0.462, P =.041; R = 0.592, P =.006) and bird-beak angle (R = 0.680, P &lt;.001; R = 0.712, P &lt;.001). Conclusions: TEVAR bird-beak severity can be quantified and predicted with geometric modeling techniques, and the combination of high preoperative aortic inner curvature and diameter increases the risk for development of TEVAR bird-beaking