TRUST Technique for Neurointervention: A Promising Alternative for Complex Cases

BACKGROUND

Neurointervention via Transradial Access (TRA) is becoming increasingly popular as experience with this technique increases. However, approximately 8.6-10.3% of complex TRA cases are converted to femoral access due to a lack of support or radial artery spasm. This study aimed to assess the efficacy and safety of the TRUST (trans-radial coaxial catheter technique using a short sheath, Simmons catheter, and Tethys intermediate catheter) technique in interventional procedures via TRA.

METHODS

This was a single-center retrospective analysis of 16 patients admitted to our institute between January 2023 to May 2023 to undergo endovascular interventions with the TRUST technique via the TRA.

RESULTS

The mean age of the study population was 63.8 years, and 62.5% were male (10/16). The most common procedure was intracranial atherosclerotic stenosis (93.75%, 15/16). All procedures were performed successfully, and the most common procedures in our cohort were ballooning (50.0%, 8/16), stenting (18.75%, 3/16), and both procedures combined (31.25%, 1/16). All procedures were performed using the TRA, and the distal and proximal radial arteries were used for access in 31.35% (5/16) and 68.75% (11/16) of the cases, respectively. Technical success was achieved in all patients and most cases demonstrated mTICI ≥2b recanalization (93.75%, 15/16). In this case, no major access-site complications occurred.

CONCLUSION

The TRUST technique is technically safe and feasible and had a high technical success rate and low complication rate in our study. These results demonstrate that the TRUST technique is a promising alternative for patients undergoing complex neurointerventions.

Morphology and Hemodynamics of Cerebral Arteries and Aneurysms in a Rare Pair of Monozygotic Twins

In this preliminary study, the underlying pathophysiology mechanisms of cerebral aneurysms (CAs) in monozygotic twins (MTs) were investigated via a rare pair of MTs (twin A and twin B) involving four reconstructed arterial models using preclinical information. First, dimensions and configurated outlines of three-perspective geometries were compared. Adopting an in-vitro validated numerical CA model, hemodynamic characteristics were investigated in the MTs, respectively. Despite expected genetic similarities, morphological comparisons show that configurations of cerebral arteries exhibit significant differences between the twins. The ICA size of twin A is larger than that in twin B (2.23~25.86%), varying with specific locations, attributing to variations during embryological developments and environmental influences. Numerical modeling indicates the MTs have some hemodynamic similarities such as pressure distributions (~13,400 Pa) and their oscillatory shear index (OSI) (0~0.49), but present significant differences in local regions. Specifically, the difference in blood flow rate in the MTs is from 16% to 221%, varying with specifically compared arteries. The maximum time-averaged wall shear stress (53.6 Pa vs. 37.8 Pa) and different local OSI distributions were also observed between the MTs. The findings revealed that morphological variations in MTs could be generated by embryological and environmental factors, further influencing hemodynamic characteristics on CA pathophysiology.

Pipeline embolization devices for the treatment of nonsaccular aneurysms in pediatric patients

Objective

Pediatric nonsaccular aneurysms are rare but challenging lesions; pipeline embolization devices (PEDs) are their potential treatment option. In this study, we aimed to evaluate the safety and efficacy of PEDs for treatment of these aneurysms.

Methods

We retrospectively selected pediatric patients with nonsaccular aneurysms treated using PEDs between June 2015 and July 2021 from our prospectively maintained database. For each patient, demographics, aneurysm characteristics, procedure details, and clinical and angiographic follow-up data were collected and summarized.

Results

This study included 16 pediatric patients with 16 nonsaccular aneurysms treated with PEDs. A median clinical follow-up time of 1,376 days was achieved in 93.75% of the patients. The complication rate of the included patients was 25%, with two patients developing mass effect, one patient undergoing major ischemic stroke, and one patient experiencing stent foreshortening after the procedure. The complete occlusion rate of aneurysms without any neurologic sequelae was 93.33%, with a median angiographic follow-up period of 246 days. The mortality rate was 6.25%.

Conclusions

The use of PEDs to treat pediatric nonsaccular aneurysms is feasible, with a high rate of complete occlusion of the aneurysm and favorable follow-up outcomes.

Anatomical variations and morphometric properties of the circulus arteriosus cerebri in a cadaveric Malawian population

BACKGROUND

Knowledge of the anatomy of the circulus arteriosus cerebri (CAC) is important in understanding its role as an arterial anastomotic structure involved in collateral perfusion and equalisation of pressure, and may explain observed variations in neurovascular disease prevalences across populations. This study was aimed at understanding the anatomical configuration and morphometric properties of the CAC in Malawian population.

MATERIALS AND METHODS

Brains were collected from 24 recently-deceased black Malawian human cadavers during medico-legal autopsies. Photographs of the CACs were taken using a camera placed at a 30 cm height from the base of the brain. Whole-circle properties and segmental vessel parameters were analysed using the OSIRIS computer programme, paying attention to completeness, typicality, symmetry, and segmental vessel diameters and lengths.

RESULTS

The complete-circle configuration was found in 69.57% of the CACs. Of these, 37.5% were typical, representing an overall typicality prevalence of 26.09%. Vessel asymmetry was observed in 30.43% of cases. There were 7 cases of vessel aplasia and 12 cases of vessel hypoplasia. The posterior communicating artery (PcoA) was the most variable (with 12 variations), widest (7.67 mm) and longest (27.7 mm) vessel while the anterior communicating artery (AcoA) was the shortest (0.78 mm). Both the AcoA and the PcoA were the narrowest vessels (0.67 mm) in this study. CAC variations in Malawian populations appeared to be similar to those observed in diverse populations.

CONCLUSIONS

Anatomical variations of the CAC exist in Malawian population and should be taken into consideration in clinical practice.

Diabetes Autoantibodies Mediate Neural- and Endothelial Cell- Inhibitory Effects Via 5-Hydroxytryptamine- 2 Receptor Coupled to Phospholipase C/Inositol Triphosphate/Ca2+ Pathway

AIMS

To identify the G-protein coupled receptor(s) on neuroblastoma and endothelial cells which mediate neural- and endothelial cell-inhibitory effects in plasma autoantibodies from a subset of older type 2 diabetes with neurologic and vascular co-morbidity. To determine the mechanism(s) of neurite retraction induced by diabetic pathologies' auto antibodies.

METHODS

Protein-A eluates from plasma of 11 diabetic patients having nephropathy, moderate-severe obesity and/or complications in which increased inflammation plays a role (depression, Parkinson's disease, atrial fibrillation, obstructive sleep apnea) were tested for neurite retraction and decreased survival in N2A neuroblastoma cells, and decreased survival in pulmonary artery endothelial cells. Specific antagonists of G protein coupled receptors belonging to the G alpha q subfamily of hetero trimetric G proteins or the phospholipase C/inositol triphosphate/Ca2+ pathway were tested for modulatory effects on diabetic pathologies' autoantibody-induced N2A neurite retraction, or cell survival.

RESULTS

Co-incubation with specific antagonists of the 5-hydroxytryptamine- 2A receptor significantly prevented acute N2A neurite retraction induced by 50-100 nM concentrations of diabetic pathologies' autoantibodies. Protection against neurite retraction (M100907> spiperone> ketanserin) closely paralleled the antagonists' potency order at the 5-HT2-AR. Neuroblastoma or endothelial cell death (after 24 hours incubation) with 50-100 nM autoantibodies was completely or nearly completely (91%) prevented by co-incubation with 200 nM M100907, a highly selective 5-HT2-AR antagonist. Alpha-1 adrenergic, angiotensin II, metabotropic glutamate 5, or endothelin A (100 nM-10µM) receptor antagonists did not substantially inhibit autoantibody-induced cell death. The intracellular calcium chelator (BAPTA-AM, 50 µM) and inhibitors of the inositol triphosphate (IP3) receptor (2-APB, 50µM), and phospholipase C-gamma (U73144, 1µM) each significantly protected against autoantibody-induced acute N2A neurite retraction.

CONCLUSION

These data suggest that neural- and endothelial- inhibitory effects in autoantibodies from older adult diabetes with nephropathy and obesity/inflammation-associated complications are mediated by agonist autoantibodies directed against the 5-hydroxytryptamine 2 receptor positively coupled to the phospholipase C/inositol triphosphate/ cytosolic Ca2+ release pathway.

Cerebral hemodynamics and pseudo-continuous arterial spin labeling considerations in adults with sickle cell anemia

Sickle cell anemia (SCA) is a genetic disorder resulting in reduced oxygen carrying capacity and elevated stroke risk. Pseudo-continuous arterial spin labeling (pCASL) measures of cerebral blood flow (CBF) may have relevance for stroke risk assessment; however, the effects of elevated flow velocity and reduced bolus arrival time (BAT) on CBF quantification in SCA patients have not been thoroughly characterized, and pCASL model parameters used in healthy adults are often applied to patients with SCA. Here, cervical arterial flow velocities and pCASL labeling efficiencies were computed in adults with SCA (n = 19) and age- and race-matched controls without sickle trait (n = 7) using pCASL in sequence with phase contrast MR angiography (MRA). Controls (n = 7) and a subgroup of patients (n = 8) also underwent multi-post-labeling-delay pCASL for BAT assessment. Mean flow velocities were elevated in SCA adults (velocity = 28.3 ± 4.1 cm/s) compared with controls (velocity = 24.5 ± 3.8 cm/s), and mean pCASL labeling efficiency (α) was reduced in SCA adults (α = 0.72) relative to controls (α = 0.91). In patients, mean whole-brain CBF from phase contrast MRA was 91.8 ± 18.1 ml/100 g/min, while mean pCASL CBF when assuming a constant labeling efficiency of 0.86 was 75.2 ± 17.3 ml/100 g/min (p < 0.01), resulting in a mean absolute quantification error of 23% when a labeling efficiency appropriate for controls was assumed. This difference cannot be accounted for by BAT (whole-brain BAT: control, 1.13 ± 0.06 s; SCA, 1.02 ± 0.09 s) or tissue T₁ variation. In conclusion, BAT variation influences pCASL quantification less than elevated cervical arterial velocity and labeling efficiency variation in SCA adults; thus, a lower labeling efficiency (α = 0.72) or subject-specific labeling efficiency should be incorporated for SCA patients.

A brain microvasculature endothelial cell-specific viral vector with the potential to treat neurovascular and neurological diseases

Gene therapy critically relies on vectors that combine high transduction efficiency with a high degree of target specificity and that can be administered through a safe intravenous route. The lack of suitable vectors, especially for gene therapy of brain disorders, represents a major obstacle. Therefore, we applied an in vivo screening system of random ligand libraries displayed on adeno‐associated viral capsids to select brain‐targeted vectors for the treatment of neurovascular diseases. We identified a capsid variant showing an unprecedented degree of specificity and long‐lasting transduction efficiency for brain microvasculature endothelial cells as the primary target of selection. A therapeutic vector based on this selected viral capsid was used to markedly attenuate the severe cerebrovascular pathology of mice with incontinentia pigmenti after a single intravenous injection. Furthermore, the versatility of this selection system will make it possible to select ligands for additional in vivo targets without requiring previous identification of potential target‐specific receptors.