Distal Vessels Research Articles

Post-ASPECTS and Post-PC-ASPECTS Predict the Outcome of Anterior and Posterior Ischemic Stroke Following Thrombectomy.

In this study, we aimed to determine whether post-Alberta Stroke Project Early CT Changes Score (post-ASPECTS) in anterior stroke and post-(posterior circulation) PC-ASPECTS in posterior stroke on CT can predict post-endovascular thrombectomy (EVT) functional outcomes among patients with acute ischemic stroke (AIS) after EVT. A total of 247 consecutive patients aged 18 and over receiving EVT for LVO-related AIS were recruited into a prospective database. The data was retrospectively analyzed between March 2019 and February 2022 from two comprehensive tertiary care stroke centers: Foshan Sanshui District People's Hospital and First People's Hospital of Foshan in China. Patient parameters included EVT within 24 hr of symptom onset, premorbid modified Rankin scale (mRS) ≤2, presence of distal and terminal cerebral blood vessel occlusion, and subsequent 24-72-hr post-stroke onset CT scan. Univariate comparisons were performed using the Fisher's exact test or χ2 test for categorical variables and the Mann-Whitney U-test for continuous variables. Logistic regression analysis was performed to further analyze for adjusting for confounding factors. A p-value of ≤0.05 was statistically significant. Overall, 236 individuals with 196 anterior circulation ischemic strokes and 40 posterior strokes of basilar artery occlusion were examined. Post-ASPECTS in anterior stroke and post-pc-ASPECTS as strong positive markers of favorable outcome at 90 days post-EVT; and lower rates of inpatient mortality/hospice discharge, 90-day mortality, and 90-day poor outcome were observed. Moreover, patients in the post-ASPECTS ≥ 7 cohort experienced shorter door-to-recanalization time (DRT), puncture-to-recanalization time (PRT), and last known normal-to-puncture time (LKNPT). Post-ASPECTS ≥7 in anterior circulation AIS and post-pc-ASPECTS ≥7 in posterior circulation can serve as strong prognostic markers of functional outcome after EVT.

A Case of 3Cs: Coronary Artery Calcification Masquerading as a Stent on Chest X-ray

Coronary artery calcification in patients with coronary artery disease is associated with increased major adverse cardiovascular events. They are usually diagnosed on a computed tomography scan or on an invasive coronary angiography. A 60-year-old male was diagnosed with acute coronary syndrome after presentation with one month of worsening angina. Coronary angiography showed triple vessel disease (mid left anterior descending artery and mid right coronary artery having total occlusion and a 70% stenosis in the left circumflex artery). Apart from this, there was a heavily calcified right coronary artery with a C configuration evident on fluoroscopy. A computed tomography coronary angiography was done to visualize the distal vessels. The calcium score was 5988. Retrospectively, on inspection of the chest X-ray, there was calcification on the right heart border. The patient was medically managed and referred to a cardiothoracic vascular surgeon for coronary artery bypass grafting. Coronary artery calcification on X-ray is rare and hence being presented along with the review of the literature.

Initial Experience with the Solitaire X 3 mm Stent Retriever for the Treatment of Distal Medium Vessel Occlusions

Endovascular therapy (EVT) is the standard treatment for ischemic stroke caused by a large vessel occlusion (LVO). The effectiveness of EVT for distal medium vessel occlusions (MDVOs) is still uncertain, but newer, smaller devices show potential for EVT in MDVOs. The new Solitaire X 3 mm device offers a treatment option for MDVOs. Our study encompassed consecutive cases of primary and secondary MDVOs treated with the Solitaire X 3 mm stent-retriever as first-line EVT device between January and December 2022 at 12 European stroke centers. The primary endpoint was a first-pass near-complete or complete reperfusion, defined as a modified treatment in cerebral infarction (mTICI) score of 2c/3. Additionally, we examined reperfusion results, National Institutes of Health Stroke Scale (NIHSS) scores at 24 h and discharge, device malfunctions, complications and procedural technical parameters. Sixty-eight patients (38 women, mean age 72 ± 14 years) were included in our study. Median NIHSS at admission was 11 (IQR 6–16). In 53 (78%) cases, a primary combined approach was used as the frontline technique. Among all enrolled patients, first-pass mTICI 2c/3 was achieved in 22 (32%) and final mTICI 2c/3 in 46 (67.6%) patients after a median of 1.5 (IQR 1–2) passes. Final reperfusion mTICI 2b/3 was observed in 89.7% of our cases. We observed no device malfunctions. Median NIHSS at discharge was 2 (IQR 0–4), and no symptomatic intracranial hemorrhages were reported. Based on our analysis, the utilization of the Solitaire X 3 mm device appears to be both effective and safe for performing EVT in cases of MDVO stroke.

Effects of Prolonged Tourniquet Application on Coagulation and Fibrinolysis in Rats

Background Pneumatic tourniquets are routinely used in major orthopedic surgeries such as total knee arthroplasty (TKA) to occlude arterial flow, control perioperative bleeding, and facilitate an unimpeded surgical field 1,2,3. Despite its common use, studies have shown prolonged tourniquet application to be associated with up to a 10% symptomatic incidence of thromboembolic events such as deep vein thrombosis and pulmonary embolism, which are major postoperative complications associated with increased morbidity and mortality. Objectives To evaluate hematologic [Von Willebrand factor (VWF), tissue plasminogen factor (TPA) and D-Dimer (DD)] and histopathologic effects of prolonged tourniquet application in Sprague Dawley rats (SD). Methods Male SD rats (n=37) weight ~325 grams were randomized to an experimental group (n=19) and control group (n=18). Under isoflurane anaesthesia, a cable zip-tie emulating a pneumatic tourniquet was applied around the hind-limb of experimental animals, immediately distal to the head of the femur, at a standardized tightness of 38 newtons using a standardized cable tie hand tool for 3-hours. Control animals remained anaesthetized for the same 3-hour period, but without tourniquet intervention. After 3-hours, the tourniquet was carefully removed on experimental animals. Then in all animals, tail vein blood samples were collected, animals were euthanized and tissue samples of distal vessels (femoral and saphenous arteries and veins) and surrounding soft tissues were extracted. All hematologic parameters were measured using respective Asserachrom antigenic kits (Diagnostic Stago), an enzyme immunoassay by ELISA method. Histologic investigation included a modified Carstairs stain for fibrin and platelets as well as routine hematoxylin-eosin (H&E) staining. Results As can be seen in Figure 1, tourniquet application in the hind limb of experimental animals resulted in complete occlusion of arterial flow distal to the device, leading to bruising, muscle stiffness and bleeding into the local tissue, and associated tissue ischemia. The experimental animals exhibited elevated plasma concentration of DD (289.3 ng/mL vs 67.37 ng/mL, p<0.05), VWF (3.4% vs 2.9%, p=0.19) and TPA (11.4 ng/mL vs 1.0 ng/mL, p<0.05) when compared to its control group (Figure 1). The gross and microscopic evaluation revealed varying degrees of vascular congestion and the presence of post-mortem clot formation in the examined samples. No histological evidence of antemortem thrombosis was observed in either group in the microscopic examination of H&E slides. Conclusion Our animal model demonstrates prolonged tourniquet application to be associated with activation of the coagulation and fibrinolysis cascade, but did not demonstrate histological evidence of antemortem thrombosis. Future animal studies are required to compare the prevalence of thrombosis in the post-operative/tourniquet period, which would mimic the temporality of DVT development in a clinical orthopedic setting. Figure 1: Left: hind limb of control animal after 3 anesthetised hours of no tourniquet application. Right: hind limb of experimental animal after 3 anesthetised hours of prolonged tourniquet application. Bleeding into local tissue, and vascular and muscular tissue damage are visible. Bottom: Microscopic examination of hindlimb blood vessel. H&E staining demonstrating (A) artery, (B) vein, and (*) erythrocytes aggregation (20x magnification). There was no evidence of thrombosis.

Abstract 048: The Tigertriever 13 for Primary Distal Vessel Occlusions (DVO) ‐ Multicenter Experience

Introduction Objective: To evaluate the safety and efficacy of the Tigertriever 13 stent retriever in acute ischemic stroke (AIS) patients with primary distal and medium vessel occlusions (DMVO). Tigertriever 13 is a low profile stentriever that enables using a small microcatheter for safer procedures. Methods This is a retrospective data analysis of consecutive 59 cases performed between 04/19‐12/22 in two German comprehensive stroke centers. These patients were either ineligible or failed thrombolysis. Mean age was 75 and pre‐procedure NIHSS was 8,2 (SD 5,1), 55,9% Male, 37,2% were treated and failed thrombolysis treatment. These patients were admitted with disabling deficits that localize to the territory of the distal vessels. The occluded locations were 58,0% MCA M3, 0,0% MCA M4, 22,0% ACA, 20,0% PCA. All patients were treated with Tigertiever 13 with a mean of 1,7 passes where 100% under general anesthesia. Successful recanalization of the occluded vessel was measured by TICI score and intraoperative complications were recorded for safety evaluation. Results The mean time from symptoms onset to groin puncture was 200 minutes, and a successful recanalization rate of TICI 2b‐3 was observed in 72,8% of the patients while NIHSS was improved from 8,2 at baseline to 5,7 at discharge. There were 11,8% asymptomatic intracranial hemorrhages (ICH) and 0,5% symptomatic ICH. Conclusion The Tigertriever 13 device with operator controllability and high fluoroscopy visibility and its small size can potentially provide a safe and effective clot removal in patients with distal vessels occlusion. The effectiveness and safety profile in these patients with distal occlusions is comparable to those of patients with proximal occlusions.

Abstract 002: Examining Pulling Force Using Combined Stentreiver and Aspiration Technique in a Medium Vessel Thrombectomy Model

Introduction With the advent of smaller stent retrievers (SR) and aspiration catheters (AC) capable of accessing more distal locations, distal and medium vessel occlusions (DMVO) are emerging as promising targets for endovascular thrombectomy (EVT). However, considering the vulnerability of distal vessels to injury, it is imperative to understand the safety of various frontline techniques in these challenging scenarios. Using a vascular flow model, we sought to investigate the optimal size, strategy, and positioning of a stent retriever and aspiration catheter to minimize the pulling force exerted on the M2 vasculature. Methods We used a silicone vascular flow model with moderate tortuosity that replicated the left‐sided anterior circulation, including middle cerebral artery (MCA) branches in the M2 territory. An 8 French Cook Shuttle guide sheath was inserted coaxially with a Catalyst 7‐132 cm aspiration catheter and TrevoTrak 21 microcatheter. To measure pulling force, an Imada force gauge DST‐1A was placed at the M2 and a DST‐11A at the proximal end of the microcatheter. The Solitaire 4x20 mm Solitaire stent‐retriever was pulled at 4 mm/sec with the AC in the proximal cavernous carotid segment (NoAsp), proximal M1 (M1P), and distal M1 (M1D), a total of 8 times per AC position, using the ingestion technique. The pinching technique was also examined using the 4x20mm stent. Results The average pulling force measured on M2 using the 4x20mm stent was 169.1mN with the AC docked in the proximal NoAsp position, 26.5mN with the AC at M1P, and 23.0mN at M1D (p<0.0001). The difference in pulling force between M1P and M1D was not significant (p=0.472). The average pulling force exerted on M2 from pinching the 4x20mm stent with the AC at M1D, rather than ingestion of the stent at M1D, was 62.9mN. Average pulling force was noted to decrease from the first to the last run in most cases, with an average drop of 26.4% at the fourth run. Conclusion ADAPT and stent‐retrieval have recently been shown to be comparable in DMVO (1), however some studies have suggested a combined approach may reduce bleeding complications compared to stent‐retrieval alone (2). In our in‐vitro model, we demonstrated that positioning the AC in M1 (M1D or M1P) reduced the pulling force exerted by the stent‐retriever on M2 compared with AC placement in the cavernous carotid (NoAsp). The pulling force exerted from pinching the 4x20mm stent with the AC at M1D was higher than with the ingestion technique, for which the explanation is uncertain, but may be due to the additional friction in the M1 segment. Taken together, these findings suggest a combined approach decreases frictional pulling force during stent‐retrieval and is safer than SR alone. We also note that the pulling force of each stent decreased after its third usage, in line with the manufacturer’s instructions for use, which suggest no more than 3 retrievals per stent (3). Future experiments will compare a wider range of techniques using stents of varying sizes to better clarify factors associated with decreased pulling force in EVT.

Abstract 233: First‐line Techniques for Endovascular Therapy of Primary Distal medium Vessel Occlusion Stroke: A Matched Analysis

Introduction Previous studies did not show a difference in terms of safety and efficacy among first‐line stent retriever (SR), contact aspiration (CA), or combined techniques for proximal large vessel occlusion strokes. However, the optimal reperfusion therapy in patients with primary distal medium vessel occlusion (DMVO) strokes is uncertain. We aimed to compare the clinical and procedural outcomes among first‐line SR, CA and combined techniques in patients with primary DMVO. Methods This is a retrospective analysis of a prospectively maintained database from 14 comprehensive stroke centers in the US and Europe. Patients were included if they had a primary DMVO stroke due to MCA‐M3/M4, ACA‐A1/A2‐3, or PCA‐P1/P2‐3 and underwent mechanical thrombectomy with first‐line SR, CA, or combined technique. The primary outcome was FPE defined as eTICI 2c/3 on the first pass. Secondary outcomes included mFPE defined as eTICI 2b/3 on the first pass, successful reperfusion defined as eTICI 2b/3 at the end of the procedure. Clinical outcomes included 90‐day mRS0‐1 and 90‐day mRS0‐2. Safety measures included procedural complications, symptomatic intracranial hemorrhage (sICH), and 90‐day mortality. The secondary analysis aimed to identify the procedural and clinical outcomes in 3 matched cohorts: (SR vs. CA), (SR vs. combined technique), and (CA vs. combined technique). Results A total of 365 patients were eligible for analysis; 38.1% were female, with a mean age of 69.3 years and a median NIHSS score of 11 [7‐18]. The first‐line SR group consisted of n=74 (20.3%), CA group n=142 (38.9%), and combined technique group n=149 (40.8%). Patients with first‐line SR or combined technique had a lower median NIHSS score, less frequent MCA‐M3 segment occlusion, and less usage of the rescue strategy compared to those with first‐line CA, P<0.05. Patients with first‐line CA had less frequent BGC usage and lower rates of FPE and procedural complications compared to first‐line SR or combined technique, P<0.05. Successful reperfusion at the end of the procedure was similar among the 3 groups (Figure). On multivariable analysis, there was no difference in terms of primary, secondary outcomes, or safety measures among the 3 first‐line techniques, except for higher procedural complications in patients who underwent the first‐line combined technique compared to those with first‐line CA (aOR 3.66, 95% CI [1.25‐10.75], P=0.02). The matched analyses did not show any difference in the primary outcome: (1) (SR, n=54 vs. CA, n=54) FPE; 31.5% vs. 26.9%, P=0.61, aOR 1.33, 95% CI [0.57‐3.11], P=0.52), (2) (SR, n=72 vs. combined technique, n=54) FPE; 37.5% vs. 31.9%, P=0.48, aOR 1.48, 95% CI [0.73‐3.03], P=0.28), and (3) (CA, n=109 vs. combined technique, n=109) FPE; 24.1% vs. 25.7%, P=0.78, aOR 0.94, 95% CI [0.50‐1.74], P=0.84). Similarly, there was no difference in terms of secondary outcomes and safety measures. Conclusion Our study suggests that in patients with primary DMVO, first‐line SR, CA, and combined techniques have a similar rate of FPE with no differences in final reperfusion or clinical outcomes. Randomized clinical trials are warranted

Aspiration Versus Stent‐Retriever as First‐Line Endovascular Therapy Technique for Primary Medium and Distal Intracranial Occlusions: A Propensity‐Score Matched Multicenter Analysis

Background For acute proximal intracranial artery occlusions, contact aspiration may be more effective than stent‐retriever for first‐line reperfusion therapy. Due to the lack of data regarding medium vessel occlusion thrombectomy, we evaluated outcomes according to first‐line technique in a large, multicenter registry. Methods Imaging, procedural, and clinical outcomes of patients with acute proximal medium vessel occlusions (M2, A1, or P1) or distal medium vessel occlusions (M3, A2, P2, or further) treated at 37 sites in 10 countries were analyzed according to first‐line endovascular technique (stent‐retriever versus aspiration). Multivariable logistic regression and propensity‐score matching were used to estimate the odds of the primary outcome, expanded Thrombolysis in Cerebral Infarction score of 2b–3 (“successful recanalization”), as well as secondary outcomes (first‐pass effect, expanded Thrombolysis in Cerebral Infarction 2c‐3, intracerebral hemorrhage, and 90‐day modified Rankin scale, 90‐day mortality) between treatment groups. Results Of the 440 included patients (44.5% stent‐retriever versus 55.5% aspiration), those treated with stent‐retriever had lower baseline Alberta Stroke Program Early Computed Tomography Scale scores (median 8 versus 9; P <0.01), higher National Institutes of Health Stroke Scale scores (median 13 versus 11; P =0.02), and nonsignificantly fewer medium‐distal occlusions (M3, A2, P2, or other: 17.4% versus 23.8%; P =0.10). Use of a stent‐retriever was associated with 15% lower odds of successful recanalization (odds ratio [OR], 0.85; [95% CI 0.74–0.98]; P =0.02), but this was not significant after multivariable adjustment in the total cohort (adjusted OR, 0.88; [95% CI 0.72–1.09]; P =0.24), or in the propensity‐score matched cohort (n=105 in each group) (adjusted OR, 0.94; [95% CI 0.75–1.18]; P =0.60). There was no significant association between technique and secondary outcomes in the propensity‐score matched adjusted models. Conclusion In this large, diverse, multinational medium vessel occlusion cohort, we found no significant difference in imaging or clinical outcomes with aspiration versus stent‐retriever thrombectomy.

Abstract 217: Influence of CT Perfusion on Decision‐Making for Endovascular Thrombectomy in Distal Occlusions: A Multi‐center Analysis

Introduction There is increasing interest in performing endovascular thrombectomy (EVT) for distal occlusions. Decision making for distal and medium vessel occlusions (DMVO) is variable and factors associated with undergoing the treatment at present remain incompletely characterized. Methods From our prospectively maintained multi‐center registry encompassing four comprehensive stroke centers in the greater Houston area, we identified patients with DMVO acute ischemic stroke (AIS). Patients with occlusions in and beyond the M2 segment, A2 segment, and P2 segment were included. The primary outcome was the likelihood of undergoing EVT, which was analyzed using multivariable logistic regression. We adjusted for time of day of presentation, NIHSS score, ASPECTS, and TPA administration, with the primary independent variable being whether CTP was used in the patient’s evaluation. Secondary outcomes included discharge modified Rankin Scale (mRS), dichotomized 0‐3 vs. 4‐6 Results Among 269 patients with distal occlusions, the median age was 68 (IQR 18), median NIHSS score was 12 (IQR 11), 47.2% were female, and 39.4% received TPA. The most common occlusion locations were M2 (77.7%) followed by P2 (9.7%), and 12.6% comprised the remainder of the occlusions. 166 (61.7%) underwent CTP and 37.9% underwent EVT. Median infarct core on CTP was 18.8 cc and penumbra was 83.1 cc. In multivariable analysis, patients evaluated with CTP were less likely to undergo EVT (OR 0.56 [95% CI ‐1.11;‐0.02]). CTP usage was also associated with a non‐significant reduced likelihood of good discharge outcome (OR 0.59, [95% CI 0.33;1.02]). Conclusion In our multi‐center cohort, patients with DMVO screened with CTP were nearly 50% less likely to undergo EVT. While the modality may assist with occlusion detection, it may also influence whether treatment is offered.

Abstract 012: First‐line Stent Retriever Versus Contact Aspiration or Combined Technique for Posterior Cerebral Artery Occlusion EVT

Introduction The optimal reperfusion technique in patients with isolated posterior cerebral artery (PCA) occlusion is uncertain. Previous studies in LVO and MeVO have demonstrated a correlation between good clinical outcomes and the first pass effect (FPE, eTICI 2c/3 on the first pass) but no differences in FPE rates or clinical outcomes between first‐line endovascular therapy techniques.1‐6 We compared clinical and technical outcomes with first‐line stent‐retriever (SR), contact aspiration (CA), or combined techniques in patients with isolated PCA occlusion. Methods This international cohort study was conducted at 30 sites in Europe and North America and included consecutive patients with isolated PCA occlusion and pre‐stroke modified Rankin Scale (mRS) 0‐3, presenting within 24 hours of time last seen well from January 2015 to August 2022.7 The primary outcome was the first‐pass effect (FPE), defined as eTICI 2c/3 on the first pass. Secondary outcomes included final successful reperfusion (eTICI 2b‐3), 90‐day excellent outcome (mRS 0 to 1), 90‐day functional independence (mRS 0 to 2), sICH, and 90‐day mortality. Patients treated with SR, CA, or combined technique were compared with multivariable logistic regression. This study was registered under NCT05291637. Results There were 326 patients who met inclusion criteria, consisting of 56.1% male, median age 75 (IQR 65‐82) years and median NIHSS 8 (5‐12). Occlusion segments were PCA P1 (53.1%), P2 (40.5%), and other (6.4%). Intravenous thrombolysis was administered in 39.6%. First‐line technique was SR, CA, and combined technique in 43 (13.2%), 106 (32.5%), and 177 (54.3%) patients, respectively; FPE was achieved in 62.8%, 42.5%, and 39.6%, respectively. Compared to SR, FPE was lower in patients treated with first‐line combined technique and similar in patients treated with first‐line CA (combined vs. SR: aOR 0.35 [0.016‐0.80], p=0.01; CA vs. SR: aOR 0.45 [0.19‐1.06], p=0.07). Final successful reperfusion (eTICI 2b‐3) was present in 81% of cases with no differences between treatment groups. Excellent outcome (mRS 0‐1) occurred in 30.7% of patients and functional independence (mRS 0‐2) occurred in 50.0% of patients. There were lower odds of functional independence in the first‐line CA versus SR alone group (aOR 0.52 [0.28‐0.95], p=0.04). FPE was associated with higher rates of favorable outcomes (mRS 0‐2: 58% vs. 43.4%, p=0.01; mRS 0‐1: 36.6% vs. 25.8%, p=0.05). sICH was observed in 5.6% (18/326) and mortality in 10.9% (35/326) with no differences between first‐line technique. Conclusion In patients with isolated PCA occlusion undergoing EVT, first line SR was associated with a higher rate of FPE compared to CA or combined techniques with no difference in final successful reperfusion. Functional independence at 90‐days was more likely with first‐line SR compared to CA in adjusted analyses. FPE was associated with higher rates of 90‐day excellent outcomes and functional independence. No difference in sICH or mortality was noted across the three techniques. As the endovascular field evolves to treat patients with distal vessel occlusion and milder severity of stroke, optimizing the efficacy and safety of the procedure is essential.8

Abstract 232: Endovascular Thrombectomy for Distal Vessel Occlusions in Early vs Extended Time Window

Introduction There has been a growing body of literature in recent years suggesting the safety and efficacy of endovascular thrombectomy (EVT) in patients with acute ischemic stroke (AIS) from distal vessel occlusion (DVO). Limited data is available regarding the risks and benefits of EVT in this patient population, especially when comparing the early window (6 hours from LKW) to the extended window (6‐24 hours from LKW). We aim to study this further. Methods We queried our stroke registry, a prospectively maintained database of AIS patients who presented from December 2014 to July 2023, and isolated patients with DVO who underwent EVT. DVO was defined as M2, M3, M4 occlusion, ACA occlusion, and/or PCA occlusion. We then further subdivided this into two groups, patients within the early window, and patients within the extended window. We compared characteristics between these groups using univariate analysis. We additionally performed a multivariable logistic regression analysis adjusted for Alberta Stroke Program Early CT Score (ASPECTS), National Institutes of Health Stroke Scale (NIHSS) score, age, sex, and use of intravenous (IV) thrombolysis to investigate whether or not extended window thrombectomy was associated with worse outcome. Our primary outcomes were modified Rankin Score (mRS) at discharge and at 90 days. Results Total of 290 patients had DVO and underwent EVT. Of these, 214 had all relevant data. 147 (68.7%) underwent EVT in the early window and 67 (31.3%) received EVT in the extended window. Mean age was 72.3 (±14.4). There were more women in the extended window 51.5% vs 44.8% (χ² = 20.57, p‐value < 0.001). No significant difference was observed in the average NIHSS between early (13.7) and extended (13.9) windows (t=‐0.44, p=0.66). Similarly, the median ASPECTS score was comparable between early (9.3) and extended (9.0) windows (t=1.41, p=0.16). As expected, there was a striking difference seen in patients receiving IV thrombolysis between early (54.5%) and extended (4.5%) windows (χ²=48.48, p<0.001). Post‐operative hematoma also was not different between the early (23.8%) and extended (14.9%) windows (χ² = 0.69, p‐value = 0.40). Symptomatic intracerebral hemorrhage (SICH) was only seen in 3.4% of patient in the early window and 2.9% of patients in extended window. No significant difference was found in the mRS at discharge (early: 3.1, extended: 3.4, t=‐0.90, p=0.37) or at 90 days (early: 3.1, extended: 3.5, t=‐1.08, p=0.29). Additionally, in our multivariable logistic regression model, receiving EVT in the extended window didn't significantly affect the discharge mRS (β=0.10, p=0.27) or the 90 day mRS (β=‐0.15, p=0.38). In this model, increasing age, lower ASPECTS score, and higher admission NIHSS predicted a higher discharge mRS, while IV thrombolysis was linked to a lower discharge mRS. Higher admission NIHSS was associated with a higher mRS at both discharge and 90 days. Conclusion In our study, outcome of EVT in the extended time window in patients with DVO was comparable to EVT outcome in early window, with no increased hemorrhagic complications. More studies are required to further understand the risks and benefits of EVT in patients with DVO stroke

Abstract 058: General anesthesia versus conscious sedation during endovascular thrombectomy for distal vessel occlusions

Introduction Choice of anesthesia for endovascular thrombectomy in large vessel occlusion of the anterior circulation has been well studied, although practice patterns may still be variable. Anesthesia choice for distal vessel occlusions (DVO) presents unique challenges, however. General anesthesia (GA) may offer advantages over conscious sedation (CS) due to reduced patient movement facilitating catheter navigation, but concerns persist about potential delays and hypotension impacting collateral circulation. In our study, we aim to explore this question further. Methods In our prospectively maintained stroke registry from December 2014 to July 2023, we identified patients with DMVO defined as M2, M3, M4 occlusion, ACA occlusion, and PCA occlusion, who underwent MT for AIS. We compared patients who received CS to those who GA. Our primary outcome measures were length of procedure defined as time from entering angiography suite until final recanalization, access time to recanalization, CS to GA conversion rate, number of passes to reach TICI2b or better and first pass effect. Our secondary outcomes were length of stay, and modified Rankin Scale (mRS) at 5 days, 30 days, and 90 days. Results Total of 290 patients with DVO were identified, the median age was 73 (IQR 19). Of these, 86 patients (29.7%) underwent GA, and 200 (69.0%) received CS. CS to GA conversion was required in 36 patients (12.4%). Females accounted for 47.5% of the CS group and 38.4% of the GA group. No significant differences were found between the two groups in the racial and gender composition (p>0.1). The mean admission NIHSS was significantly higher in the GA group (16.86) compared to the CS group (12.44) as was the rate of IV thrombolysis in the CS (36.2%) group compared to GA (31.4%) group (p<0.01). The type of anesthesia used was not influenced by the laterality of the stroke in the middle cerebral artery territory (left vs right) (χ²=0.39, p=0.53). After adjusting for age, sex, IV thrombolysis, and admission NIHSS, CS usage did not result in an increase in procedural time (β=1.3, p=0.83). Furthermore, CS had no significant effect on the total number of passes (β=‐0.15, p=0.53), nor did it influence the likelihood of achieving first‐pass recanalization (β=0.28, p=0.48). No associations were found between CS use and the modified Rankin Scale (mRS) at 5 days (β=0.17, p=0.65), 30 days (β=0.22, p=0.75), or 90 days (β=0.15, p=0.67). Likewise, the length of stay in the hospital (β=1.71, p=0.77) was not significantly affected by the use of CS. Conclusion In our analysis of DMVO, the use of CS during thrombectomy appeared to be safe and feasible and comparable to GA with regards to procedural length, number of passes, and rate of first pass recanalization. Similarly, the type of anesthesia did not have an impact on clinical outcome. Further studies are needed to build on these findings and inform optimal management strategies.

Safety and effectiveness of the modified stent retrieval technique in elderly patients with secondary distal vessel occlusion

Safety and effectiveness of the modified stent retrieval technique in elderly patients with secondary distal vessel occlusion

VEGF-A-induced changes in distal outflow tract structure and function

PurposeTo investigate changes in distal outflow tract vessels caused by VEGF-A and their impact on outflow.MethodsWe compared VEGF-A perfused porcine anterior segments with and without trabecular meshwork (TM) to control eyes. In the first experiment (n=48), we analyzed live changes of the outflow tract with spectral-domain optical coherence tomography (SD-OCT) over 3 h and reconstructed them in 3D. In a second experiment (n=32), we measured the intraocular pressure (IOP) variation in response to VEGF-A over 48 h and computed the outflow facility.ResultsVEGF-A increased the vessel volume of the distal outflow tract by 16.8±10.6% while control eyes remained unchanged (0.5±6.8%). Volume changes occurred within the first 100 min before plateauing at 140 min. VEGF-A enhanced the outflow facility in eyes without TM by 38.6±25.5% at 24 h as compared to controls (p<0.05).ConclusionVEGF-A dilated vessels of the distal outflow tract and increased the outflow facility even after TM removal, pointing to a regulatory mechanism independent of proximal structures.

A new segment method for pulmonary artery and vein.

Accurate differentiation between pulmonary arteries and veins (A/V) holds pivotal importance in the realm of diagnosing and treating pulmonary ailments. This study presents a new approach that leverages grayscale differences between A/V. Distinctions are measured using median and mean grayscale values within the vessel area. Initially, adherent regions are removed based on vessel structure. The trunk regions are segmented using gray level information near the heart region of the lung boundary. Incorrectly segmented vessels are corrected based on connectivity. For distal lung vessels, a similar distance field is established using a graph-cut method. Experimental results show the algorithm's superior segmentation accuracy, achieving 97.26% compared to the CNN-based average accuracy of 91.67%. Error branches are more concentrated, aiding subsequent manual and automatic correction. This demonstrates the algorithm's effective segmentation of pulmonary A/V.

Management of Obturator Vein Hemorrhage by Pubic Ramus Osteotomy During Acetabular Fixation - a Technical Trick.

It is known that hemorrhage from pelvic ring and acetabular fractures can cause hemodynamic instability. Methods to improve visualization and thus management of bleeding vessels are not commonly described. This report highlights techniques to manage hemorrhage from a retracted obturator vein during the definitive fixation of a complex acetabular fracture. After uncomplicated modified Stoppa anterior intrapelvic approach, abrupt and profuse bleeding was encountered from the distal end of a lacerated obturator vein, which had retracted into the obturator foramen. With unsuccessful attempts to achieve hemostasis, a superior pubic osteotomy was performed which allowed excellent visualization of the bleeding vein and ligation. It must be emphasized that the surgeon attempted all these other measures before performing an osteotomy. This technical trick contributes to the overall knowledge as a means of achieving emergent hemostasis associated with distal obturator vessel hemorrhage, a well described risk in complex acetabular fractures.

Impact of coronary bifurcation angle on stent malapposition in a randomized comparison between proximal optimization technique followed by side branch dilatation and kissing balloon inflation.

The impact of coronary bifurcation angle (BA) on incomplete stent apposition (ISA) after crossover stenting followed by side branch (SB) intervention has not been established. A total of 100 crossover stentings randomly treated with proximal optimization technique followed by short balloon dilation in the SB (POT-SBD group, 48 patients) and final kissing balloon technique (KBT group, 52 patients) were analyzed in the PROPOT trial. Major ISA with maximum distance>400μm and its location was determined using optical coherence tomography before SB intervention and at the final procedure. The BA was defined as the angle between the distal main vessel and SB. Optimal POT was determined when the difference in stent volume index between the proximal and distal bifurcation was greater than the median value (0.86mm3/mm) before SB intervention. Major ISA was more frequently observed in the POT-SBD than in the KBT group (35% versus 17%, p<0.05). In the POT-SBD group, worsening ISA after SBD was prominent at the distal bifurcation. The BA was an independent predictor of major ISA (odds ratio 1.04, 95% confidence interval 1.00-1.07, p<0.05) with a cut-off value of 59.5° (p<0.05). However, the cases treated with optimal POT in the short BA (<60°) indicated the lowest incidence of major ISA. In the KBT group, BA had no significant impact. A wide BA has a potential risk for the occurrence of major ISA after POT followed by SBD in coronary bifurcation stenting.

Application of high-resolution magnetic resonance vessel wall image in the treatment of M1 segment stenosis of middle cerebral artery

To investigate the application of high-resolution magnetic resonance vessel wall image (HRMR-VWI) in treating middle cerebral artery (MCA) M1 segment stenosis. We retrospectively analyzed preoperative clinical data, imaging data, preoperative evaluation, stent procedure, and postoperative complications in 35 patients with atherosclerotic stenosis of the MCA M1 segment. And the 30-day postoperative mortality and disability and the 12-month restenosis were followed up. There were 21 males and 14 females, with a median age of 55 and a median duration of 1 month from onset to stenting. DSA confirmed that the stenosis locates in the M1 segment, with a stenosis degree of (75.00±17.15) %, a stenosis length of (4.34±1.51) mm, and a blood vessel diameter of (2.25±0.42) mm. After the operation, there was 1 case of death after a craniotomy to remove hematoma+decompression due to reperfusion hemorrhage. There were two technical complications during the procedure (1 case of asymptomatic occlusion of the A1 segment due to the covering of stent at the initial part of A1, 1 case of intraparenchymal hematoma in the temporal lobe due to penetrating distal small blood vessel with guide wire). HRMR-VWI is of great value in observing plaques' location, morphology, and stability. It can improve the safety and effectiveness of stenting treatment of MCA M1 segment stenosis.

Contemporary Methods for Detection and Intervention of Distal Medium and Small Vessel Occlusions.

The efficacy of using mechanical thrombectomy for proximal large vessel occlusions has been demonstrated in multiple large-scale trials and has further raised the question of its potential utility for distal medium and small vessel occlusions (DMSVOs). Their longer, more tortuous course and smaller corresponding vascular territories render a significant challenge for detection and intervention. The aim of this study is to provide a comprehensive overview of the current imaging and endovascular intervention options for DMSVOs and review the current works in the literature. Compared with traditional computed tomography angiography (CTA) and CT perfusion, recent advances such as multiphase CTA and maps derived from the time-to-maximum parameter coupled with artificial intelligence have demonstrated increased sensitivity for the detection of DMSVOs. Furthermore, newer generations of mini stent retrievers and thromboaspiration devices have allowed for the access and navigation of smaller and more fragile distal arteries. Preliminary studies have suggested that mechanical thrombectomy using this newer generation of devices is both safe and feasible in distal medium-sized vessels, such as M2. However, endovascular intervention utilizing such contemporary methods and devices must be balanced at the discretion of operator experience and favorable vascular anatomy. Further large-scale multicenter clinical trials are warranted to elucidate the indications for as well as to strengthen the safety and efficacy of this approach.

Intentional creation of dissection flaps to treat perforations during chronic total occlusion percutaneous coronary intervention

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) carries a non-negligible risk of coronary perforation. Definitive treatment of a proximal large vessel perforation often requires the use of covered stents; however, the latter carry significant risk of restenosis and thrombosis, and is not feasible if wire control of the distal vessel has not been achieved. We describe two cases of target vessel perforations during CTO PCI which were treated by the intentional creation of dissection flaps using the subintimal tracking and re-entry technique to seal the perforation.