Percutaneous catheter-based repeat revascularization in patients with previous PCI or CABG: a comprehensive review of the evidence

Repeat revascularization after percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) is one of the most common long-term complications which warrants continuous clinical follow up. Re-interventions negatively impact long-term survival in patients with coronary artery disease. The repeat revascularization after PCI can be either a target lesion revascularization (stent thrombosis/in-stent restenosis) or a revascularization of native coronary artery after PCI (target vessel revascularization/non-target vessel revascularization). The EVENT registry reports that repeat revascularization rates in patients undergoing PCI is 12% in the first year of follow up. Repeat revascularization with additional stent deployment increases the rate of stent thrombosis and restenosis, thereby leading to recurrent ischemic events. Repeat revascularization after CABG can be either in the early postoperative period or later due to native disease progression or late graft stenosis. The need for re-intervention after surgical or percutaneous revascularization is inevitable and is dependent on modifiable and non-modifiable risk factors.

The feasibility evaluation of transapical saddle-shaped valved stent for transcatheter mitral valve implantation

Background: Transcatheter mitral valve implantation (TMVI) is a promising and minimally invasive treatment for high-risk mitral regurgitation (MR). The purpose of this study was to investigate the feasibility of a novel self-expanding valved stent for transcatheter mitral valve implantation via apical access. Methods: A novel self-expanding mitral valved stent system was designed and fabricated for the in vivo evaluation. It is consists of an atrial flange and a saddle-shaped ventricular body connected by two opposing anchors and two opposing extensions. During the valve deployment, each anchor is controlled by a recurrent string. TMVI was performed in ten pigs using the valve prosthesis through the apical access to verify technical feasibility. Echocardiography and ventricular angiography were used to assess hemodynamic data and valve function. The surviving pigs were sacrificed four weeks later to confirm stent deployment. Results: Ten animals underwent transapical mitral valve implantation with the novel mitral valved stent. Optimal valve deployment and accurate anatomical adjustment were obtained in nine animals. Implantation failed in one case, and the animal died one day later due to stent mismatch. After stent implantation, the hemodynamic parameter of other animals was stable and valve function was normal. The mean pressure across the mitral valve and left ventricular outflow tract (LVOT) were 2.98±0.91mmHg and 3.42±0.66 mmHg, respectively. The macroscopic evaluation confirmed the stable and secure positioning of the stents in the mitral valve. No obvious valve displacement, embolism, and paravalvular leakage were observed four weeks after valve implantation. Conclusions: This study proved that the novel mitral valved valve stent is technically feasible in animals. This device features opposing anchors, opposing recurrent strings, and saddle-like ventricular portions, providing structural design details for reducing TMVI complications. However, the long-term feasibility and durability of this valved stent need to be improved and verified.

Automated segmentation of metal stent and bioresorbable vascular scaffold in intravascular optical coherence tomography images using deep learning architectures

Percutaneous Coronary Intervention (PCI) with stent placement is a treatment effective for coronary artery diseases. Intravascular optical coherence tomography (OCT) with high resolution is used clinically to visualize stent deployment and restenosis, facilitating PCI operation and for complication inspection. Automated stent struts segmentation in OCT images is necessary as each pullback of OCT images could contain thousands of stent struts. In this paper, a deep learning framework is proposed and demonstrated for the automated segmentation of two major clinical stent types: metal stents and bioresorbable vascular scaffolds (BVS). U-Net, the current most prominent deep learning network in biomedical segmentation, was implemented for segmentation with cropped input. The architectures of MobileNetV2 and DenseNet121 were also adapted into U-Net for improvement in speed and accuracy. The results suggested that the proposed automated algorithm’s segmentation performance approaches the level of independent human observers and is feasible for both types of stents despite their distinct appearance. U-Net with DenseNet121 encoder (U-Dense) performed best with Dice’s coefficient of 0.86 for BVS segmentation, and precision/recall of 0.92/0.92 for metal stent segmentation under optimal crop window size of 256.

Removal of Partially Deployed Supera Stents: Case-Based Review and Technical Considerations

Purpose: Maldeployment of the Supera stent system can result in primary technical failure, inferior primary patency, and poorer patient outcomes. The purpose of this article is to present a case series illustrating the conditions required to perform optimal stent deployment, and if necessary, undertake successful stent removal following maldeployment. Technique: Two key failures of effective Supera deployment are elongation and invagination. Several technical factors should be considered to reduce the risk of maldeployment: aggressive target vessel predilation, the use of multiple fluoroscopic views, slow deployment with controlled forward pressure applied on the delivery device, “sandwich packing” of the stent above and below target lesions, and the “pulling back” of invagination. To successfully retrieve a partially deployed stent, 3 factors should be considered: the percentage of the stent already deployed, the distance from the distal tip of the introducing sheath to the proximal extent of the deployed stent, and the severity of proximal vessel disease. The higher these factors, the greater the risk of stent detachment and failed retrieval. Conclusion: In this series of 6 cases of maldeployment, the removal of a partially deployed Supera stent appeared to be feasible and safe, with success dependent on selected technical and anatomical considerations.

Percutaneous Transluminal Angioplasty in Chronic Total Subclavian Venous Stenosis Using Coronary Guidewire: A Case Report

Arteriovenous fistula is the best permanent vascular access for hemodialysis (HD). However, in our country, HD catheter in jugular or subclavian vein is more commonly found because our patients prefer to hold HD until the complications are unbearable. The catheter increases risk of venous stenosis on site and in surrounding vessels, resulting in access loss. Percutaneous transluminal angioplasty (PTA), combined with stent deployment, can be utilized as main treatment for such stenosis in subclavian vein. This method dated back to two decades ago with high success rate. Nevertheless, reports or studies of angioplasty in total occlusion are scarce, mainly because of lower success rate and the need of smaller penetrating wire. We describe our experience in performing PTA and stent deployment using coronary wire to penetrate total occlusion in subclavian venous stenosis after vein cannulation. We hope that we can give an alternative technique to avoid surgery in such cases.

Abstract 1122‐000218: Flow Reversal After Stent Diversion Causes In‐Stent Thrombosis and Anemia‐Driven Ischemia

Introduction : Large symptomatic ICA aneurysms are rare, but present a life threatening risk of rupture that increases with size, female sex, and age >50 at the time of diagnosis, among other risk factors. Historically, large carotid aneurysms have been treated with intentional carotid sacrifice, requiring recruitment of contralateral, posterior, and ECA‐supplied collaterals to provide flow to the anterior circulation previously supplied by the sacrificed ICA, lest the patient experience an iatrogenic stroke. While still a viable option in some cases, flow diverting stents provide an attractive alternative to vessel sacrifice. By providing a channel for blood to bypass the aneurysm, the stent can effectively exclude the aneurism from active circulation while preserving a path for blood to travel to the anterior cerebral circulation it currently provides. Methods : Here, we present a case of a 1.3 cm symptomatic left cavernous ICA aneurysm treated with such a flow diverting stent. Results : The patient presented to the emergency department with left sided ptosis. CTA head and neck revealed the 1.3 cm left sided cavernous ICA aneurysm. She was treated endovascularly under general anesthesia with continuous intra‐operative monitoring. The procedure was complicated by iatrogenic flow reversal through the Circle of Willis at the time of stent deployment and resultant in situ thrombosis of the stent without alteration in electrical signals recorded at the scalp – thus creating a de facto carotid sacrifice without intra‐operative complication. Follow up doppler study revealed a loss of flow through the left ICA and reversal of flow through the ophthalmic artery on the left side, thus confirming ECA collateral supply to the area. Post‐op course was complicated by extensive bleeding from the scalp electrode sites used for intraoperative monitoring due to hyper‐response to aspirin‐ticagrelor dual‐antiplatelet therapy. This gave rise to a symptomatic anemia that manifested as pressure‐dependent left‐sided circulatory failure on exam – specifically hemiparesis and aphasia. The symptoms ultimately resolved with pressure augmentation, blood transfusion, and supportive care in the Neuro ICU. The patient was successfully transitioned to a general neurology floor with subsequent resolution of the anemia and, correspondingly, the symptoms. Conclusions : The patient was discharged to rehab and at 4‐month follow‐up is again living independently with no residual deficits. This case has significance for pre‐operative anti‐platelet optimization for flow diverting stents, management of post‐operative complications of flow‐diverting stent placement including thrombosis and bleeding, and optimal critical care support for patients with pressure‐dependent ischemia. Specifically, the course of the patient’s symptoms and anemia raise the question of optimal hemoglobin targets in the subset of patients with pressure‐dependent ischemia, and how to best reach those targets.

Abstract 1122‐000202: Two World Wars, Two Pandemics and Then Stroke:Thrombectomy, Angioplasty and Stenting in a 110‐Year‐Old Patient

Introduction : Endovascular thrombectomy (EVT) is the standard of care in patients with acute stroke due to large vessel occlusion. In an aging population it is important to know EVT outcomes in old age, despite patients over 80 years are mostly excluded from major trial. While the oldest reported patients undergoing EVT was 102 years old, we report a 110 years old patient as the oldest patient undergoing EVT for stroke reported in the literature, and discuss the technical details and outcome. Methods : n/a Results : A 110‐ year‐old patient presented with right side weakness and slurred speech and found to have left middle cerebral artery occlusion. She received tenecteplase and transferred to angio‐suite 1 hour and 35 minutes after onset of symptoms. Left middle cerebral artery underwent two passes with stentriever, balloon angioplasty and stent deployment resulting in thrombolysis in cerebral infarction (TICI) 3 reperfusion. Brain MRI showed infarction in the left basal ganglia and left temporal cortex. After thrombectomy she was able to hold right arm and leg against gravity and follow commands. However, patient developed aspiration pneumonia and passed away after family chose to focus care on her comfort and refused tracheostomy and gastric tube. Conclusions : Despite poor clinical outcome, this case presents technical success in good recanalization, resulting in small infarct core and immediate neurological improvement in the oldest reported acute stroke patient undergoing thrombectomy.