Abstract 1122‐000194: Incidence of Access Site Complications in Patients Receiving Tenecteplase as Bridging Therapy to Endovascular Treatment

Introduction : Mechanical thrombectomy (EVT) is the standard of endovascular care for acute ischemic stroke secondary to large vessel occlusion. Alteplase in conjunction with EVT has a strong safety profile with low incidence of complications including groin hematoma. Our objective was to evaluate the incidence of groin hematoma in EVT following bridging therapy tenecteplase (TNK) as this is not well‐described in the literature. Methods : Retrospective review of prospectively collected data for patients with acute ischemic stroke who underwent mechanical thrombectomy at a University Hospital. Incidence of access site complication including groin hematoma, retroperitoneal hematoma, blood loss and femoral artery pseudoaneurysm with or without the need for surgical intervention were reviewed. Rates of use of other antithrombotic agents were also noted. Social Science Statistics was used for data analysis. Results : From October of 2020 to April of 2021, of 348 ischemic stroke patients, 16 had LVO identified on CT and received TNK prior to mechanical thrombectomy (Females = 6; age, 63.25 95% CI [54.9207, 71.5793]); Mean weight = 78kg, 95% CI [67.68, 88.32]). Five subjects (31.25%) received intra‐arterial non‐thrombolytics. None received intra‐arterial thrombolytics. Three patients (18.75%) received therapeutic heparin during the procedure. Four patients (25%) were started on non‐thrombolytic infusion during the periprocedural period. One subject (6.25%) was started on stroke nomogram heparin infusion less than 24 hours post‐intervention. One subject (6.25%) developed groin hematoma that did not require intervention. This subject received intra‐arterial non‐thrombolytics during procedure and IV non‐thrombolytics during the peri‐procedural period. Conclusions : Our single center experience with TNK outside of the clinical trial setting with concomitant use of other antithrombotics suggests safety of bridging strategy. Larger prospective ‘real‐life’ studies are required to validate our findings.

Low profile sheaths in pediatric neurointervention: a multicenter experience

BackgroundPediatric neurointervention is challenged by the appropriateness of adult catheters and devices. This multicenter report on the smallest groin access sheaths offers technical notes and clinical outcomes in the pediatric neurointerventional population.MethodsAll pediatric neurointerventional cases from 2019 to 2021 were reviewed for use of a 3.3F Pediavascular or a 4F Merit Prelude Ideal low profile sheath. Hospital records were reviewed for complications and technical notes and compared with arterial groin access with the 4F Terumo Pinnacle in infants less than 1 year old, before the low profile sheaths at one author’s institution were introduced.ResultsFrom January 1, 2019 to March 31, 2021 there were 347 procedures performed at Boston Children’s Hospital and University of Wisconsin. Forty-four procedures in 26 patients were identified in which a 3.3F (38 cases, 20 patients) or 4F (6 cases, 6 patients) sheath was used. The average age was 2.2 years (1.5 days to 18 years). Retinoblastoma intra-arterial chemotherapy infusion (18 of 44) was the most common indication. The remaining procedures comprised vein of Galen embolization (12), diagnostic cerebral angiography (13), and one preoperative tumor embolization. Morbidity included a groin hematoma and decreased pulses (4.5%). No major groin complications occurred. There was no statistically significant difference compared with the historical cohort (132 procedures), which had seven instances of decreased pulses (5.3%, p>0.05).ConclusionThe 3.3F Pediavascular and 4F Merit Prelude Ideal sheaths are easily incorporated into the pediatric neurointerventionalist’s armamentarium for infants and readily accommodate various microcatheters for distal embolization and catheterization.

Thromboelastography (TEG) results are predictive of ischemic and hemorrhagic complications in patients with unruptured intracranial aneurysms treated with flow diversion

Introduction Flow diversion is an effective treatment modality for intracranial aneurysms but is associated with ischemic and hemorrhagic complications. Patients treated with flow diversion require dual antiplatelet therapy and subsequent platelet function tests. At our institution, Thromboelastography with Platelet Mapping (TEG-PM) is the test of choice. The primary objective of this study was to identify TEG parameters that are predictive of postoperative complications in patients treated with elective flow diversion. Methods This was a retrospective study of 118 patients with unruptured intracranial aneurysms treated with flow diversion. Data was collected via chart review. Bivariate analyses were performed to identify significant variables in patients who suffered an ischemic stroke or a groin hematoma. ROC curves were constructed for the TEG parameters with statistical significance. Bivariate analyses were repeated using dichotomized TEG results. Results Patients who experienced a symptomatic ischemic stroke had a history of stroke (p value = 0.007), larger aneurysm neck width (p value = 0.017), and a higher alpha angle (p value = 0.013). Cut off point for ischemic complication is 63° on ROC curve with a sensitivity of 100% and specificity of 65%. Patients who experienced a groin hematoma were no different from their healthy peers but had a lower alpha angle (p value = 0.033). Cut off point for hemorrhagic complication is 53.3° with a sensitivity of 82% and specificity of 67%. Conclusion The Alpha Angle parameter of TEG-PM has a sizeable predictive ability for both ischemic complications of the central nervous system and hemorrhagic complications of the access site after elective flow diversion.

Long Vascular Sheaths for Transfemoral Neuroendovascular Procedures in Children

Purpose: To evaluate the safety and efficacy of long vascular sheaths for transfemoral neuroendovascular procedures in children.Materials and Methods: A retrospective evaluation of transfemoral neuroendovascular procedures in children <18 years, using long sheaths was undertaken analyzing procedure type, fluoroscopic times, technical success, access site and systemic complications. Twenty-seven consecutive procedures were included over a two-year period. Mean age was 8.4 years (standard deviation [SD] 6.3) (range 17.0 months–16.3 years).Results: Patients were 44% female and mean weight was 35.0 kg (SD 22.8) (range 9.8–72.2 kg). A third of the procedures were performed in ≤15 kg children. The most common procedure was for embolization (n=13, 48.1%) and the most common indication was dual microcatheter technique (52%). The most common device used was the 5 Fr Cook Shuttle sheath. Mean fluoroscopy time was 61.9 minutes (SD 43.1). Of these procedures, 93% were technically successful. Femoral vasospasm, when present, was self-limiting. Complications (3/27, 11.1%) included groin hematoma (n=1), neck vessel spasm that resolved with verapamil (n=1), and intracranial thromboembolism (n=1), with no significant difference between the ≤15 kg and >15 kg subcohorts. There were no aorto-femoro-iliac or limb-ischemic complications.Conclusion: Long vascular sheaths without short femoral sheaths can be safely used for pediatric neuroendovascular procedures as they effectively increase inner diameter access without increasing the outer sheath diameter. This property increases the range of devices used and intracranial techniques that can be safely performed without arterial compromise, thus increasing the repertoire of the neurointerventionalist.

Safety and efficacy of Angio-Seal device for transfemoral neuroendovascular procedures: A systematic review and meta-analysis

Introduction Angio-Seal is a commonly used device for femoral hemostasis in neuroendovascular procedures. This meta-analysis investigates of the safety and efficacy of Angio-Seal in patients undergoing endovascular neurointerventional procedures. Methods A systematic review and meta-analysis on all studies evaluating the Angio-Seal device in neurointerventional procedures from inception through 2020 were performed. We studied rates of groin hematoma, retroperitoneal hematoma, pseudoaneurysm, ipsilateral DVT, and ischemic complications. Meta-analysis was performed using the random-effects model. Results 13 studies were included in our analysis. 2250 patients with 104 complications were found {4.5% (95% CI, 2.7%–6.3%)}. Of these complications, groin hematoma was the most common with a rate of 2.4% (95% CI, 1.1%–3.6%). Retroperitoneal hematoma {0.3% (95% CI, 0%–0.5%)}, pseudo-aneurysm {0.5% (95% CI, 0.2%–0.8%), and ipsilateral DVT {0.3% (95% CI, 0.1%–0.7%) were also not in negligible rate. The rate of other complications were as follows: vessel occlusion/stenosis; 0.2% (95% CI, 0%–0.4%), vascular surgery; 0.2% (95% CI, 0%–0.5%), and infection; 0.2% (95% CI, 0%–0.5%). One patient died as result of hemorrhagic complications {0.1% (95% CI, 0%–0.3%)}. Use of anticoagulant/antiplatelet therapy was found to be positively correlated with high risk of any groin complication and groin hematoma (p ≤ .05). Female gender was associated with high risk of ipsilateral DVT (p ≤ .05). Interestingly, large sheath size was associated with low risk of groin hematoma (p ≤ .05). Conclusion The safety and efficacy rate of Angio-Seal was approximately 95%. The most common complication was groin hematoma. Serious complications including retroperitoneal hematoma and femoral artery occlusion were rare.

Common Femoral Artery Access: 2-Dimensional Operative Video

Vascular access for cerebral angiography has traditionally been performed via the common femoral artery. It is crucial to obtain safe access to prevent complications that could lead to limb ischemia, groin hematoma, or retroperitoneal hematoma. This is especially true in neurointervention as many patients are anticoagulated or have received intravenous thrombolytics prior to their intervention. Special attention to anatomic landmarks, both grossly and radiographically, can help to assure safe access. The patient consented for this procedure. This video details rapid but safe femoral artery access in a patient undergoing emergent thrombectomy.

Nivolumab (NIVO) and drug eluting bead transarterial chemoembolization (deb-TACE): Preliminary results from a phase I study of patients (pts) with liver limited hepatocellular carcinoma (HCC).

525 Background: Regional therapies in HCC impact the immune microenvironment and may augment the effects of immune checkpoint inhibitors. Methods: This is a multicenter phase 1 study of NIVO and deb-TACE in unresectable HCC pts (BCLC Stage B) and Child Pugh A cirrhosis (NCT03143270). The primary objective is to assess safety. Secondary objectives include response rate by RECIST v1.1, progression-free and overall survival by Kaplan-Meier methodology, and blood/tumor immune correlates. A 3 + 3 design sequentially evaluates 3 cohorts of differing schedules of NIVO relative to deb-TACE. Deb-TACE (75mg of doxorubicin) is administered on Day 0. NIVO is dosed at 240mg IV every 14 days for 1 year (Cohort 1: NIVO begins day +14 after deb-TACE; Cohort 2, interrupted NIVO dosing begins at Day -28 but is held on the Day 0 then restarted on Day +14; Cohort 3, continuous NIVO dosing begins on Day -28 without interruption). Results: As of July 2019, 9 pts have been treated [median 65 years (range: 54-76), male (89%), viral (44%;1 HBV, 3 HCV), non-viral (56%;2 EtOH, 1 NASH, 2 unknown), prior resection (44%), prior regional therapy (44%), 3 pts in each cohort]. No cases of treatment related liver failure, dose-limiting toxicity, or Grade 5 adverse events (AEs) were observed. Grade ≥3 AEs possibly related to nivolumab, deb-TACE, or both included: transaminase elevation (1 pt: day 1 post TACE resolved in 7 days without treatment; 2 pts: ≥30 days post TACE resolved with steroids between 20-41 days), post-embolization syndrome (1 pt: resolved in 5 days), asymptomatic lipase increase (1 pt: resolved in 14 days), post-procedural groin hematoma (1 pt: resolved in 2 days). All 9 pts were evaluable for efficacy: 2 (22%) confirmed PR and 7 (78%) SD. 4/9 pts remain on study with SD or better—2 pts continue > 18 months post embolization with durable PRs. 12 months OS rate was 71%. Ongoing correlates will be presented at a separate meeting. Conclusions: Nivolumab given at various times relative to deb-TACE appears safe and tolerable. Cohort 3 continues to accrue to provide a better estimate of safety and antitumor activity of the combination. Clinical trial information: NCT03143270.

Protocoled thrombolytic therapy for frostbite improves phalangeal salvage rates

Background Frostbite is a cold injury that has the potential to cause considerable morbidity and long-term disability. Despite the complexity of these patients, diagnostic and treatment practices lack standardization. Thrombolytic therapy has emerged as a promising treatment modality, demonstrating impressive digit salvage rates. We review our experience with thrombolytic therapy for severe upper extremity frostbite. Methods Retrospective data on all frostbite patients evaluated at our institution from December 2017 to March 2018 was collected. A subgroup of patients with severe frostbite treated with intra-arterial thrombolytic therapy (IATT) were analysed. Results Of the 17 frostbite patients treated at our institution, 14 (82%) were male and the median age was 31 (range: 19–73). Substance misuse was involved in a majority of the cases (58.8%). Five (29.4%) patients with severe frostbite met inclusion criteria for IATT and the remaining patients were treated conservatively. Angiography demonstrated a 74.5% improvement in perfusion after tissue plasminogen activator thrombolysis. When comparing phalanges at risk on initial angiography to phalanges undergoing amputation, the phalangeal salvage rate was 83.3% and the digit salvage rate was 80%. Complications associated with IATT included groin hematoma, pseudoaneurysm and retroperitoneal hematoma. Conclusions Thrombolytic therapy has the potential to greatly improve limb salvage and functional recovery after severe frostbite when treated at an institution that can offer comprehensive, protocoled thrombolytic therapy. A multi-center prospective study is warranted to elucidate the optimal treatment strategy in severe frostbite.