Is aspiration an effective acute stroke treatment in older adults?

Introduction: Clinical outcomes after interventional stroke treatment rely on several factors, with older age being associated with poorer results, which are mainly attributed to patient's comorbidities and medications. The delivery of an aspiration catheter could be hindered by carotid tortuosity, which is more prevalent in elderly patients with increasing age. In this study, we aimed to compare the clinical and angiographic outcomes of a direct aspiration first-pass technique in interventional stroke treatment for elderly patients compared with younger patients. Materials and methods: A total of 162 patients (92 women and 70 men, aged between 35 and 94 years +/- 12.4 years) were included in this study. Patients who were treated in a comprehensive stroke center due to a large-vessel occlusion stroke using aspiration as the first-choice treatment were included in this study. To evaluate carotid arteries, the tortuosity index (TI) was calculated for each segment of each carotid pathway. Results: Age correlated significantly with the presence of carotid tortuosity (R = 0.408, p = 0.000), extracranial length ratio (R = 0.487, p = 0.000), and overall length ratio (R = 0.467, p = 0.000). No significant associations were found with coiling, kinking, or intracranial length ratio. Successful aspiration-based recanalization rate decreased with increasing age, and the differences between the age subgroups were not statistically significant. A comparison of the extreme subgroups, i.e., <60 years old vs. ≥80 years old, did not yield a statistically significant change (p = 0.068). Conclusion: Successful aspiration-based recanalization rate decreased with increasing age; however, these differences were not significant. Clinical outcomes did not significantly differ with regard to carotid tortuosity, regardless of the time of assessment. Neither intracranial nor extracranial tortuosity was significantly associated with reperfusion-related complications in either of the age subgroups.

Prediction of Hemodynamic-Related Hemolysis in Carotid Stenosis and Aiding in Treatment Planning and Risk Stratification Using Computational Fluid Dynamics.

Atherosclerosis affects human health in many ways, leading to disability or premature death due to ischemic heart disease, stroke, or limb ischemia. Poststenotic blood flow disruption may also play an essential role in artery wall impairment linked with hemolysis related to shear stress. The maximum shear stress in the atherosclerotic plaque area is the main parameter determining hemolysis risk. In our work, a 3D internal carotid artery model was built from CT scans performed on patients qualified for percutaneous angioplasty due to its symptomatic stenosis. The obtained stenosis geometries were used to conduct a series of computer simulations to identify critical parameters corresponding to the increase in shear stress in the arteries. Stenosis shape parameters responsible for the increase in shear stress were determined. The effect of changes in the carotid artery size, length, and degree of narrowing on the change in maximum shear stress was demonstrated. Then, a correlation for the quick initial diagnosis of atherosclerotic stenoses regarding the risk of hemolysis was developed. The developed relationship for rapid hemolysis risk assessment uses information from typical non-invasive tests for treated patients. Practical guidelines have been developed regarding which stenosis shape parameters pose a risk of hemolysis, which may be adapted in medical practice.

Mechanical thrombectomy of large vessel occlusion using adjustable vs. self-expanding stent-retriever-Comparison of Tigertriever device with stent-like stent-retrievers: A propensity score analysis.

Background: Stent-retrievers used for mechanical thrombectomy are self-expanding tubular stent-like devices with modified mesh structures for clot removal. Tigertriever is designed to provide manual control of its diameter and curvature. Methods: A retrospective single-center study was performed to compare Tigertriever with SolitaireX and pRESET (stent-like stent-retrievers group) using propensity score analysis. Patients treated in a comprehensive stroke center due to large vessel occlusion between January 2016 and August 2021 were evaluated. Baseline characteristics and treatment results were compared between these groups before and after pair matching. Results: There were 140 patients (60 in Tigertriever and 80 in the stent-like stent-retriever group). In propensity score analysis, 52 matched pairs were selected in Tigertriever and stent-like stent-retriever groups. The Tigertriever group had a better successful first pass revascularization rate [46 vs. 23%, OR (95% CI): 1.7 (1.1-2.9), p = 0.013] and 14-min shorter groin-to-revascularization time (51 vs. 65 min. p = 0.017). There were no significant differences between Tigertriever and stent-like stent-retriever groups in the following: favorable mRS 3 months, favorable recanalization rate, and symptomatic intracerebral hemorrhages. There were no observed periprocedural adverse events related to Tigertriever, SolitaireX, or pRESET. Conclusion: Tigertriever had a significantly better successful first pass revascularization rate and shorter groin-to-revascularization time in the analysis done before and after propensity score matching with stent-like stent-retrievers. Tigertriever is comparable to stent-like stent-retrievers regarding mortality at 3 months, favorable mRS at 3 months, favorable recanalization rate, or symptomatic cerebral hemorrhagic events.

Inadvertent Detachment of Stent Retrievers during Mechanical Thrombectomy-A Clinical and Biomechanical Perspective.

BACKGROUND: The inadvertent detachment of stent retrievers during mechanical thrombectomy is an extremely rare but feared complication associated with poor clinical outcomes. We discuss management considerations after an unexpected disconnection of the pRESET stent retriever during mechanical thrombectomy, based on clinical experience and mechanical and phantom studies. METHODS: We present a clinical course of rare accidents of stent-retriever separation inside an intracranial vessel that occurred in patients in a comprehensive stroke centre between 2018 and 2020. We designed a phantom study to assess the Tigertriever's ability to remove a detached stent retriever from intercranial vessels. In the mechanical study, several types of stent retrievers were evaluated in order to find the weakest point at which detachment occurred. RESULTS: Two patients (~0.7%) with inadvertent stent-retriever detachment were found in our database. Failed attempts of endovascular removal with no recanalization at the end of procedure were reported in both cases. mRS after 3 months was three and four respectively. In the mechanical study, the Tigertriever was the most resistant to detachment and was followed by Embotrap > pRESET > 3D Separator. In the phantom study, the pRESET device detached in a configuration resembling the M1 segment was successfully removed with the Tigertriever. CONCLUSIONS: Conservative management of the inadvertent detachment of stent retrievers during mechanical thrombectomy in large vessel occlusion may be acceptable in order to avoid further periprocedural complications after unsuccessful device removal attempts. Based on the phantom and mechanical studies, the Tigertriever may be a useful tool for the removal of detached pRESET devices.

Initial experience with novel Embocure Plus microspheres for transarterial chemoembolization (TACE) of liver metastatic colorectal cancer tumours - a clinical and in vitro study.

PURPOSE: Transarterial chemoembolization (TACE) is currently recommended for unresectable intrahepatic tumours with no vascular invasion or metastasis to other organs. It is based on drug-eluting microspheres pre-loaded with chemotherapeutics, which are injected selectively into vessels supplying the tumour, to embolize them inducing ischaemia, and elute the drug, to induce tumour response. We present our initial experience with novel irinotecan- loaded Embocure Plus microspheres in patients with metastatic colorectal cancer tumours in the liver, and their effect on HCT-116 cell cultures in vitro. MATERIAL AND METHODS: Three consecutive male patients (median age 62 [50-76] years) with liver metastatic colorectal cancer tumours were selected. All patients had a pre-procedure contrast-enhanced computed tomography, confirming multiple metastatic liver tumours (mean tumour diameter = 42 mm; range: 14-77 mm) and periprocedural dyna-CT scans for rapid treatment results assessment. In vitro: Human colon HCT116 cancer cell line was cultured, irinotecan loaded Embocure Plus microspheres were added. Cultures were assessed after 24 hours and 72 hours of incubation in normoxia or hypoxia. RESULTS: All embolizations were technically successful, and no complications were observed. Stabilization of the targeted metastatic liver tumours in all patients was noted. In vitro: Significant decrease of the growth of HTC 116 cell lines were observed in controls compared to cells treated with Embocure Plus loaded with irinotecan in normoxia and hypoxia after 48 and 72 hours. We observed a tendency for less inhibited cell proliferation in low-oxygen conditions. CONCLUSIONS: TACE therapy of liver metastatic tumours shows satisfactory results and a low complication rate. Embocure Plus microspheres are safe and technically feasible for superselective chemoembolization of metastatic colorectal cancer liver tumour. Dyna-CT can be used for assessment of treatment results during repeated TACE procedures.

A new in vitro model applied 90Y microspheres to study the effects of low dose beta radiation on colorectal cancer cell line in various oxygenation conditions.

We propose a new in vitro model to assess the impact of 90Y-microspheres derived low-dose beta radiation on colorectal cancer cell line under various oxygenation conditions that mimic the tumor environment. Cancer cells (HCT116) proliferation was assessed using Alamar Blue (AB) assay after 48, 72, and 96 h. FLUKA code assessed changes in cancer cell populations relative to the absorbed dose. In normoxia, mitochondrial activity measured by Alamar Blue after 48-72 h was significantly correlated with the number of microspheres (48 h: r = 0.87 and 72 h: r = 0.89, p < 0.05) and absorbed dose (48 h: r = 0.87 and 72 h: r = 0.7, p < 0.05). In hypoxia, the coefficients were r = 0.43 for both the number of spheres and absorbed dose and r = 0.45, r = 0.47, respectively. Impediment of cancer cell proliferation depended on the absorbed dose. Doses below 70 Gy could reduce colorectal cancer cell proliferation in vitro. Hypoxia induced a higher resistance to radiation than that observed under normoxic conditions. Hypoxia and radiation induced senescence in cultured cells. The new in vitro model is useful for the assessment of 90Y radioembolization effects at the micro-scale.

Intra-aneurysmal pressure changes during stent-assisted coiling.

We aimed to examine aneurysm hemodynamics with intra-saccular pressure measurement, and compare the effects of coiling, stenting and stent-assisted coiling in proximal segments of intracranial circulation. A cohort of 45 patients underwent elective endovascular coil embolization (with or without stent) for intracranial aneurysm at our department. Arterial pressure transducer was used for all measurements. It was attached to proximal end of the microcatheter. Measurements were taken in the parent artery before and after embolization, at the aneurysm dome before embolization, after stent implantation, and after embolization. Stent-assisted coiling was performed with 4 different stents: LVIS and LVIS Jr (Microvention, Tustin, CA, USA), Leo (Balt, Montmorency, France), Barrel VRD (Medtronic/ Covidien, Irvine, CA, USA). Presence of the stent showed significant reverse correlation with intra-aneurysmal pressure-both systolic and diastolic-after its implantation (r = -0.70 and r = -0.75, respectively), which was further supported by correlations with stent cell size-r = 0.72 and r = 0.71, respectively (P<0.05). Stent implantation resulted in significant decrease in diastolic intra-aneurysmal pressure (p = 0.046). Systolic or mean intra-aneurysmal pressure did not differ significantly. Embolization did not significantly change the intra-aneurysmal pressure in matched pairs, regardless of the use of stent (p>0.05). In conclusion, low-profile braided stents show a potential to divert blood flow, there was significant decrease in diastolic pressure after stent placement. Flow-diverting properties were related to stent porosity. Coiling does not significantly change the intra-aneurysmal pressure, regardless of packing density.

Safety and Efficacy of Mechanical Thrombectomy Using Tigertriever as a Rescue Device After Failed Aspiration-Single Center Experience.

Introduction: We evaluated the safety and efficacy of a new stent retriever-Tigertriever-after failed aspiration. Materials and Methods: Patients with acute ischemic stroke treated with Tigertriever between January 2018 and March 2020 were included in the study. Treatment results of Tigertriever in rescue therapy (after failed aspiration) were evaluated. Periprocedural data were retrospectively analyzed. Results: Thirty patients were treated with Tigertriever (14M/16F). There were 20 rescue thrombectomies after failed aspiration. Tigertriver successful recanalization rate (mTICI ≥ 2B) was 70%: 65% in rescue therapy and 80% in first-line therapy. The type of first line treatment had no impact on mRS after 1 month and 3 months (ns). There was significant improvement in NIHSS in all patients (mean NIHSS: 17 vs. 10, p = 0.028), in rescue treatment (mean NIHSS: 17 vs. 11, p = 0.048) and in first line treatment (mean NIHSS: 16 vs. 8, p = 0.0005). Better results in NIHSS at discharge were linked with first pass success (p = 0.002), better mTICI at the end of the procedure (p = 0.0006), and administration of rtPA (p = 0.013). Conclusions: The new stent retriever Tigertriever is an efficient and safe tool to be used as a rescue device after an unsuccessful first line aspiration technique.

Gallbladder Radiation Protection in SIRT-Quantitative Anatomical Study of Hepatic Vasculature.

Introduction: This study was designed to assess quantitatively a safe position of the microcatheter during the SIRT (Selective Internal Radiation Therapy) procedure, in order to minimize the risk of non-target spheres leaking. Materials and Methods: Retrospective analysis of the distance of the tip of the microcatheter from coiled or patent non-target arteries was measured during 99mTc-MAA work-up procedure. Frequency of extrahepatic leaking during work-up and SIRT procedures was evaluated. Results: There were 85 patients who underwent 98 work-up procedures. There were 64 radioembolizations. There were 44 gastroduodenal, 51 right gastric, and 54 cystic artery embolizations performed. Extrahepatic 99mTc-MAA leaking was observed in 33 cases: 16 to gallbladder, four to a gastric wall, nine to the duodenum, one to the intestinal wall, and three to the abdominal wall. Leak in 99mTc-MAA was also related to the presence of additional arteries (p = 0.009). There were 34 proximal and 31 distal to cystic artery 99mTc-MAA injections resulting in 12 vs. four leaks, respectively (p = 0.039, RR-2.5). Mean distance of the tip of the microcatheter from the origin of the cystic artery was 20 mm (minimum of 2.1 mm and maximum of 53 mm) proximally and 10 mm (minimum 1 mm and maximum 51 mm) distally (ns). Conclusions: Leaking in 99mTc-MAA (99mTc - labelled macroaggregated albumin) was related to the presence of additional arteries. Regardless of cystic artery embolization, it is 2.5 times safer to inject microspheres distal to its origin, compared to proximal injection. Cystic artery origin relative to the right hepatic artery division usually necessitates embolization of the former.