A systematic review of current trends in pharmacologic management after stent placement in nonthrombotic iliac vein lesions

Objective Stenting of the iliac vein is increasingly recognized as a treatment for chronic venous insufficiency (CVI). However, the pharmacologic management after stent placement is unclear. This review was conducted to illustrate recent trends in anticoagulation and antiplatelet regimens following stent placement for nonthrombotic iliac vein lesions (NIVL). Methods The MEDLINE database was searched using the term “iliac vein stent.” Retrieval of articles was limited to studies conducted on humans and published in English between 2010 and 2020. Studies were included that described iliac vein stent placement. Studies were excluded that contained fewer than 25 patients, performed procedures other than stent placement, did not specify the postoperative anticoagulant used, or treated lesions of thrombotic origin. Results 12 articles were included in this review, yielding a total of 2782 patients with a male-to-female ratio of 0.77. The predominant CEAP classification encountered was C3. The most common stent used in the included studies was the Wallstent (9/12), and the most common pharmacologic regimen was 3 months of clopidogrel (6/12). Warfarin, aspirin, cilostazol, and rivaroxaban were among other agents used. Primary stent patency ranged from 63.1 to 98.3%. There was no apparent correlation between pharmacologic agent used and stent patency or subjective patient outcomes. Conclusion Multiple different approaches are being taken to pharmacologically manage patients following stent placement for NIVL. There is no consensus on which agent is best, nor is there a formal algorithmic approach for making this decision. Additionally, the findings in this study call into question whether anticoagulation following stenting for NIVL is necessary at all, given the similar outcomes among the different agents utilized. This review underscores the potential value of undertaking a multi-institutional prospective study to determine what is the best pharmacologic therapy following venous stent placement for NIVL.

Rescue embolization with direct coil delivery from dual-lumen balloon microcatheter

Background Balloon microcatheters are widely used for endovascular treatment. However, no reports on direct coil embolization from dual-lumen balloon microcatheters are available in the literature. This report is the first description of direct coil embolization using this type of balloon microcatheter for looming bleeding emergencies. Methods This retrospective review demonstrates the indications and advantages of coil embolization from an inflated balloon catheter to reduce blood loss and simultaneously occlude bleeding. Results Five patients who underwent emergency endovascular treatment using coil embolization directly delivered from a dual-lumen balloon were identified. Etiologies included vertebro-vertebral arteriovenous fistula, ruptured vertebral artery dissecting aneurysm, vertebral artery injury during cervical spinal operation, and failed stent retrieval procedures for acute infarction. Complete hemostasis was achieved with all procedures. Conclusion Our experience demonstrates the feasibility of direct coil embolization by using a dual-lumen balloon to rapidly halt bleeding in some rare emergency situations, which may save lives.

Retrograde thrombectomy of basilar artery thrombus through the posterior communicating artery

Transcirculation thrombectomy through the communicating arteries of the circle of Willis has been previously described as a bailout in cases where direct thrombectomy is not feasible.1–3 Here we present a unique case where a retrograde thrombectomy of the proximal basilar artery was performed using the right posterior communicating artery (PCOM) in a patient with bilateral occlusions of the vertebral arteries, believed to be chronic. This was done using a quadriaxial system with multiple concentric catheters to minimize the ledge effect and achieve smooth and safe transition of the catheters from anterior to posterior circulations. A combination of stent retrieval, aspiration and balloon occlusion guide catheters helped retrieve the thrombus, while minimizing emboli in new territory (ENT). The patient had complete resolution of symptoms. The thrombus is believed to be due to stasis at the vertebrobasilar junction and competing flow, hence, the patient was started on anticoagulation. (video 1)Video 1

Practical use and underlying physics of the BENCHMARK™ BMX™ 96 for large-bore aspiration thrombectomy: Case report of initial institutional experience

Endovascular thrombectomy (EVT) is part of first-line intervention for acute ischemic stroke management. Recent technological advances have demonstrated that large-bore catheters are an attractive approach for EVT. A multitude of approaches such as A Direct Aspiration first Pass Technique (ADAPT) or in conjunction with stent retrieval (Solumbra technique) have been developed with increasingly large-bore catheters, demonstrating safety and efficacy. Furthermore, these techniques have demonstrated promise for the intervention of cerebral venous thrombosis as well as posterior circulation ischemic events. Recently, advances in neurointerventional catheters have focused on improved maneuverability to navigate the neurovasculature, as well as larger inner diameters for improved procedural versatility, including aspiration. We describe a case report highlighting our early institutional experience with the recently developed large-bore catheter, the BENCHMARK™ BMX™ 96. The case report entails near complete occlusion of the internal carotid artery from acute thrombus and the utility of the BMX™ 96 catheter for treatment of such extensive clot burden. The applicability of large-bore aspiration catheters, with an emphasis on recent advances, for mechanical thrombectomy in arterial as well as venous systems is discussed. To our knowledge, this is the first reported case of use of the BENCHMARK™ BMX™ 96 access system for EVT in acute ischemic stroke. Such new-generation large-bore catheters are a promising advance in neurointervention, and our early institution experience highlights the ease of use and versatility for neurointerventional procedures such as EVT.

Endovascular therapy for acute stroke in children: age and size technical limitations

Endovascular therapies for acute childhood stroke remain controversial and little evidence exists to determine the minimum age and size cut-off for thrombectomy in children. Despite this, an increasing number of reports suggest feasibility of thrombectomy in at least some children by experienced operators. When compared with adults, technical modifications may be necessary in children owing to differences in vessel sizes, tolerance of blood loss, safety of contrast and radiation exposure, and differing stroke etiologies. We review critical considerations for neurologists and neurointerventionalists when treating pediatric stroke with endovascular therapies. We discuss technical factors that may limit feasibility of endovascular therapy, including size of the femoral and cervicocerebral arteries, which contributes to vasospasm risk. The risk of femoral vasospasm can be assessed by comparing catheter outer diameter with estimated femoral artery size, which can be estimated based on the child’s height. We review evidence supporting specific strategies to mitigate cervicocerebral arterial injury, including technique (stent retrieval vs direct aspiration) and device size selection. The importance of and strategies for minimizing blood loss, radiation exposure, and contrast administration are reviewed. Attention to these technical limitations is critical to delivering the safest possible care when thrombectomy is being considered for children with acute stroke.

Effect on successful recanalization of thrombus length in susceptibility-weighted imaging in mechanical thrombectomy with stent-retrieval

Introduction: Susceptibility-weighted imaging (SWI) enables visualization of thrombotic material in acute ischemic stroke. We analyzed the association between thrombus length on SWI and the success rate of recanalization in stent-retriever mechanical thrombectomy. Materials and Methods: A retrospective study was performed on 128 patients with middle cerebral artery (MCA) thrombus on pretreatment SWI. The patients were divided into 2 groups, the successful recanalization and the failed recanalization group. Thrombus visibility and location on SWI were compared to those on maximum intensity projection (MIP) in computed tomography (CT) angiography. A comparative analysis was performed in terms of clinical and radiologic outcomes as well as complications with respect to multiple categories. Results: No significant differences were noted in terms of baseline characteristics and clinical outcomes between the 2 groups. However, compared with the successful recanalization group, the failed recanalization group had a larger number of stent-retriever passages and a longer thrombus length (p = 0.027 and 0.014, respectively). Multivariate analyses revealed that a larger mean number of stent-retriever passages was a predictive factor for failure of recanalization (odds ratio [OR] 1.60; 95% confidence interval [CI] 1.12 – 2.08; p = 0.04). Thrombus length (OR 9.91; 95% CI 3.89–13.87; p < 0.001) and atrial fibrillation (OR 5.38; 95% CI 1.51 – 9.58; p = 0.008) were separately associated with more than 3 stent-retriever passages. Conclusions: Thrombus length has been identified as a predictor of recanalization failure in mechanical thrombectomy. A significant decline in the success rate of recanalization was associated with longer thrombus length.

Prevalence of and risk factors for stent migration-induced duodenal perforation

Background and study aims The safety of transpapillary biliary drainage by stent placement through endoscopic retrograde cholangiography (ERC) may be compromised by the occurrence of stent migration-induced perforation of the duodenal wall (SMDP). We aimed to assess the prevalence rate, risk factors and clinical course of SMDP. Patients and methods This retrospective cohort study included all patients who underwent an ERC with biliary plastic stent placement, between January 2014 and December 2018. Patients with an SMDP were identified from our endoscopy complication registry. Results 1227 patients underwent an ERC, of whom 629 patients (51 %) with biliary plastic stent placement; in 304 patients (25 %) stents were placed for perihilar strictures. Thirteen patients with SMDP were identified. The prevalence was 2.1 % for patients with biliary plastic stent placement and 4.3 % for patients stented for a perihilar stricture. All SMDPs occurred in patients with a perihilar stricture and with stents ≥ 12 cm (range 12–20 cm). Another potential risk factor was stent insertion into the left liver lobe, which was present in 10 of 13 patients. In 10 of 13 patients, SMDP was clinically suspected. Three of 13 patients were asymptomatic and diagnosed at elective stent retrieval. Eight patients could be endoscopically treated with an over-the-scope clip. Four patients died due to abdominal sepsis despite repeated interventions. Conclusion SMDP is a rare but potentially life-threatening complication of ERC after transpapillary drainage for perihilar biliary strictures. Stents ≥ 12 cm and stent insertion into the left liver lobe may be associated risk factors.