Endovascular Recanalization Techniques Research Articles

Endovascular Relining of Chronically Occluded Infrainguinal Venous Bypass Grafts

Treatment of chronically occluded infrainguinal venous bypass grafts in patients presenting with recurrent chronic limb threatening limb ischemia (CLTI) represent a clinical challenge. Recent case reports have suggested the use of endovascular recanalization techniques without preceding thrombolysis. This study assesses feasibility and mid-term outcomes of this technique. A retrospective review of 5 consecutive patients (3 men, 2 women, mean age 70 ± 5 years) presenting with chronic venous bypass graft occlusion and recurrence of CLTI during 1 year was performed. Patients were treated with relining of the bypass grafts. Patients were followed up at median 26 (6-36) months. All patients were treated successfully with restoration of flow in the grafts using recanalization and relining technique without thrombolysis. In 4 patients, a Viabahn stentgraft (SG) was used with the addition of interwoven nitinol stents (INS) in 3. In 1 patient, the graft was treated with INS without the addition of a stentgraft. No peripheral embolization was encountered during the procedures. One patient occluded the relined grafts after 6 months. The remaining 4 grafts were all patent at 24-month follow-up. A total of 6 reinterventions (in 3 patients) were performed to reach 80% secondary patency. This case series demonstrate feasibility and promising mid-term results, from relining of chronically occluded infra-inguinal venous bypass grafts using stent grafts, interwoven and bare-metal stents without preceding thrombolysis. The technique could be an alternative treatment option in the treatment of these challenging cases.

New Opportunities of Endovascular Recanalization Techniques in the Management of Ischemic Stroke

Currently, there are a limited number of treatments for ischemic stroke. Intravenous thrombolytic therapy is the most effective method. However, its efficacy is very low in the case of stroke caused by occlusion of large intracranial arteries. Previous studies of endovascular recanalization techniques in the treatment of stroke, particularly randomized controlled trials (RCTs), such as IMS-3, SYNTHESIS Expansion, and MR RESCUE, have shown negative results. The results of other RCTs (MR CLEAN, ESCAPE, EXTENDIA, SWIFT PRIME, and REVASCAT) published in 2015 demonstrated that, in the case of careful selection of patients with verified occlusion of large intracranial arteries, endovascular recanalization significantly improves stroke outcomes.

When Catheter Thrombosis Mimics Malignant Cava Thrombosis: The Role of Endovascular Interventions

SESSION TITLE: Disorders of the Mediastinum 1 SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Superior Vena Cava (SVC) obstruction can occur due to malignant etiologies or benign causes including endovenous devices like central catheters. We present a case of persistent erythematous facial edema secondary to catheter associated SVC obstruction. CASE PRESENTATION: A 53 year old female with stage IV colon cancer treated by means of resection and chemotherapy via a left internal jugular vein (IJV) port developed catheter associated SVC thrombosis two years prior to presentation. Despite anti-coagulation with a direct factor Xa inhibitor, she had progression of the clot requiring removal of the port followed by insertion of a femoral port which later became infected. She then had a new port inserted from the right IJV. She presented with persistent facial swelling and plethora, headache and dizziness. She had numbness and tingling of her extremities. She had recently experienced transient left-sided upper and lower extremity weakness during a chemotherapy session. On physical examination, her vital signs were normal. She had significant swelling of the face and fullness in her neck along with facial plethora (Figure 1A). The laboratory parameters were normal. Computed tomography of chest demonstrated complete occlusion of the SVC distal to the origin of a hypertrophied azygos to the right atrium (Figure 1B). The tip of the right sided port terminated in the hypertrophied azygos. The first attempt at percutaneous wire recanalization of the SVC was unsuccessful. Due to persistent SVC syndrome and need for maintenance of long term venous access, she underwent a successful sharp recanalization of SVC and stent graft placement followed by placement of a right-sided IJV port with the catheter extending through the stent into the right atrium (Figure 2). The patient reported immediate decrease in facial swelling after the procedure and was discharged on long term anticoagulation therapy with low molecular weight heparin. DISCUSSION: Patients with SVC obstruction from benign causes often present with symptoms that can be confused with other etiologies. In a patient with history of vascular access procedures these symptoms, especially facial swelling, should prompt consideration of SVC obstruction. Once clinically detected, appropriate use of imaging can identify cause and location of SVC obstruction and facilitate treatment. Conventional percutaneous endovascular recanalization techniques are relatively safe and have good long-term patency1. CONCLUSIONS: Symptoms of catheter related thrombosis can be subtle or present as a more serious complication, such as SVC obstruction. There should be a low threshold to perform diagnostic work up for thrombus even in a port that appears to be working, as early intervention can have substantial impact on patient’s morbidity. Reference #1: Breault, S., et al. (2017). “Percutaneous endovascular management of chronic superior vena cava syndrome of benign causes : long-term follow-up.“ Eur Radiol 27(1): 97-104. DISCLOSURE: Cristhiam Rojas Hernandez: Grant monies (from industry related sources): Daichii Sankyo (research funding) The following authors have nothing to disclose: Yameena Jawed, Rahul Sheth, Joshua Kuban No Product/Research Disclosure Information

Prehospital care delivery and triage of stroke with emergent large vessel occlusion (ELVO): report of the Standards and Guidelines Committee of the Society of Neurointerventional Surgery

Recent randomized clinical trials1–5 established the superiority of endovascular recanalization techniques, specifically mechanical embolectomy, compared with best medical therapy alone for the treatment of patients with emergent large vessel occlusion...

Factors that determine penumbral tissue loss in acute ischaemic stroke

The goal of acute stroke treatment with intravenous thrombolysis or endovascular recanalization techniques is to rescue the penumbral tissue. Therefore, knowing the factors that influence the loss of penumbral tissue is of major interest. In this study we aimed to identify factors that determine the evolution of the penumbra in patients with proximal (M1 or M2) middle cerebral artery occlusion. Among these factors collaterals as seen on angiography were of special interest. Forty-four patients were included in this analysis. They had all received endovascular therapy and at least minimal reperfusion was achieved. Their penumbra was assessed with perfusion- and diffusion-weighted imaging. Perfusion-weighted imaging volumes were defined by circular singular value decomposition deconvolution maps (Tmax > 6 s) and results were compared with volumes obtained with non-deconvolved maps (time to peak > 4 s). Loss of penumbral volume was defined as difference of post- minus pretreatment diffusion-weighted imaging volumes and calculated in per cent of pretreatment penumbral volume. Correlations between baseline characteristics, reperfusion, collaterals, time to reperfusion and penumbral volume loss were assessed using analysis of covariance. Collaterals (P = 0.021), reperfusion (P = 0.003) and their interaction (P = 0.031) independently influenced penumbral tissue loss, but not time from magnetic resonance (P = 0.254) or from symptom onset (P = 0.360) to reperfusion. Good collaterals markedly slowed down and reduced the penumbra loss: in patients with thrombolysis in cerebral infarction 2 b-3 reperfusion and without any haemorrhage, 27% of the penumbra was lost with 8.9 ml/h with grade 0 collaterals, whereas 11% with 3.4 ml/h were lost with grade 1 collaterals. With grade 2 collaterals the penumbral volume change was -2% with -1.5 ml/h, indicating an overall diffusion-weighted imaging lesion reversal. We conclude that collaterals and reperfusion are the main factors determining loss of penumbral tissue in patients with middle cerebral artery occlusions. Collaterals markedly reduce and slow down penumbra loss. In patients with good collaterals, time to successful reperfusion accounts only for a minor fraction of penumbra loss. These results support the hypothesis that good collaterals extend the time window for acute stroke treatment.

Abstract WP8: Determinants Of Benefit From Endovascular Recanalization In Acute Ischemic Stroke: A Meta-Analysis

Background: While endovascular recanalization therapy for acute ischemic stroke has made substantial technical advance, demonstration of clinical benefit has to date been elusive. We performed a systematic meta-analysis of all clinical trials and large series of endovascular recanalization to identify features associated with good clinical outcome. Methods: We searched MEDLINE and Cochrane Registry of Clinical Trials to identify all randomized trials and large cohort series of endovascular recan for acute stroke published from 1999 - 2012. Reports were included if they used any endovascular recanalization technique in a sample of 50 or more subjects. Studies confined to patients with post circulation or ICA occlusions were excluded. Results: A total of 22 studies reporting 2185 patients met selection criteria. Interventions were intra-arterial fibrinolysis (IAF) in 6 series (467 patients), the Merci retriever in 5 (508 patients), the Penumbra system in 3 (373 patients), and stent retrievers in 5 (571 patients). Across series, average patient age was 66, 49% were female, median pretreatment NIHSS was 17, and avg time from onset to recanalization was 293 minutes. Target occlusion locations included the ICA in 17% and MCA in MCA 63%. Independent final clinical outcome (mRS ≤ 2 or nearest equivalent) was achieved in 41%, SICH occurred in 8%, and mortality rate was 23%. Factors associated with independent clinical outcome were: lower NIHSS pretreatment (r = 0.5), achievement of partial or better recanalization (r = 0.4), and onset to recanalization time (r =-0.4). A factor associated with mortality was longer time to recan (r = 0.4). With individual interventions, rates of good outcome were: IAF 51%, Merci 29%, Penumbra 32%, and stent retrievers 51%. Rates of mortality were: IAF 15%, Merci 33%, Penumbra 26%, and stent retrievers 22%. Conclusions: Independent clinical outcome after endovascular recanalization therapy is associated with lower pretreatment deficit severity, achievement of recanalization, and shorter time to recanalization. Differences in functional outcomes are noted between different endovascular recanalization techniques, likely reflecting differences in case mix and in recanalization efficiency.

Endovascular recanalization in acute ischemic stroke

It is time to systematically plan for the next era in reperfusion therapy for acute ischemic stroke—the epoch of endovascular treatment. Reperfusion therapies for acute arterial occlusions in different organ beds naturally evolve in 2 successive eras. In the first, IV thrombolysis (IVT) launches the reperfusion age, as the first useful, widely disseminated therapy, but its success is constrained by only modest recanalization rates. Then, in the second, endovascular recanalization techniques (ERTs) are developed that are far more effective at achieving reperfusion and supersede IVT alone to become the definitive, ongoing standard of care. This 2-stage pattern characterized the evolution of reperfusion therapy for both acute myocardial ischemia and acute limb ischemia. Reflecting the greater complexity and fragility of the brain and its vasculature, the evolution of acute ischemic stroke care has been slower but now can be seen to be also traversing this same historical path. The decades from 1990 to 2010 were the era of IVT for acute ischemic stroke, as IVT evolved from untested therapy through clinical trial–validated intervention to standard therapy embedded in nationwide hospital systems of care. We are now living and working in the early phase of the era of ERTs. The initial period of rapid, iterative technologic advance has been proceeding apace, as the endovascular armamentarium has expanded from intra-arterial …

Recanalization of Chronic Refractory Central Venous Occlusions Utilizing a Radiofrequency Guidewire Perforation Technique

To assess the technical success rate and safety of radiofrequency perforation guidewire (RF) technology for the recanalization of refractory chronic central venous occlusions in symptomatic hemodialysis patients with failed conventional endovascular methods. This single center retrospective cohort of hemodialysis patients comprised of six men (mean age 67 years, range 55 to 80) with autogenous fistulae, who had already undergone failed conventional endovascular methods. These patients underwent the RF perforation technique from December 2006 to January 2010. Three patients were successfully treated using the RF perforation technique, after which they had PTFE stent grafts placed at the site of occlusion. There was no recurrence of clinical symptoms. In the remaining three patients, the procedure was terminated after multiple unsuccessful attempts. There were no complications. The RF perforation technique is a potential alternative technology for recanalization of refractory chronic central venous occlusions in hemodialysis patients in the setting of failed conventional endovascular recanalization techniques.

Intra-Arterial Treatment Methods in Acute Stroke Therapy

Acute revascularization is associated with improved outcomes in ischemic stroke patients. It is unclear which method of intra-arterial intervention, if any, is ideal. Promising approaches in acute stroke treatment are likely a combination of intravenous and endovascular revascularization efforts, combining early treatment initiation with direct clot manipulation and/or PTA/stenting. In this review, we will discuss available thrombolytic therapies and endovascular recanalization techniques, beginning with chemical thrombolytic agents, followed by mechanical devices, and a review of ongoing trials. Further randomized studies comparing medical therapy, intravenous and endovascular treatments are essential, and their implementation will require the wide support and enthusiasm from the neurologic, neuroradiologic, and neurosurgical stroke communities.

Impact of Aggressive Endovascular Recanalization Techniques on Success Rate in Chronic Total Arterial Occlusions (CTOs)

To report experience with aggressive recanalization approaches in chronic total arterial occlusion (CTO). Chronic total arterial occlusion recanalization was attempted on 112 limbs in 99 consecutive patients between January 1999 and December 2006. There were 63 iliac arteries, 45 femoropopliteal arteries, and 4 occluded stents. Mean occlusion length was 8.7 ± 4.7 cm. Conventional recanalization was attempted first and was successful in 71 limbs (70%). Probing with the guidewire's stiff end was attempted in 33 of the 41 procedures where conventional techniques failed and was successful in 18 (54%), improving the overall procedural success rate to 80%. For the remaining 15 limbs, home-made directional sharp needle recanalization was attempted in 11 and was successful in 9 (82%), further improving the overall recanalization success to 88%. Procedural complications were self-limited or managed nonoperatively. Aggressive recanalization techniques in CTO following failure of traditional means are safe and can substantially improve procedural success rates.

Adjunctive techniques in percutaneous mechanical thrombectomy

Percutaneous mechanical thrombectomy is an established method in interventional radiology and refers to the removal of acute embolic or thrombotic occlusive material in arteries, veins, or vascular grafts using percutaneous transluminal methods. However, initial complete removal of occlusive material can be achieved only in a minority of patients. The amount of removed material varies with the age and composition of the occlusive material. To achieve sufficient revascularization, adjunctive use of a variety of percutaneous endovascular recanalization techniques is necessitated. Additional treatment with local intra-arterial fibrinolysis, balloon angioplasty, stent implantation, endoluminal atherectomy, and other measures results in primary technical success rates of 70% to 100% for revascularization of acutely occluded vessels. The above-mentioned different techniques should not be viewed as competitive treatment modalities, rather a synergistic approach should be offered. The aim of this report is to review different adjunctive techniques in percutaneous mechanical thrombectomy with emphasis on techniques, mechanisms of action, experimental and clinical results, potential complications, and their potential role in view of clinical pathways to treat acute limb ischemia. © 2003 Elsevier Inc. All rights reserved.