Three-dimensional fusion imaging to assess apposition of low-profile visualized intraluminal support stent for intracranial aneurysm coiling.

Objective: To investigate on three-dimensional (3D) fusion images the apposition of low-profile visualized intraluminal support (LVIS) stents in intracranial aneurysms after treatment and assess inter-rater reliability. Materials and methods: Records of all patients with unruptured intracranial aneurysms who were treated with the LVIS stent were retrospectively accessed and included in this study. Two neurosurgeons evaluated the presence of malapposition between the vessel walls and the stent trunk (crescent sign) and the vessel wall and the stent edges (edge malappostion) on 3D fusion images. These images were high-resolution cone-beam computed tomography images of the LVIS stent fused with 3D-digital subtraction angiography images of the vessels. Associations between malapposition and aneurysm location were assessed by Fisher's exact test, and inter-rater agreement was estimated using Cohen's kappa statistic. Results: Forty consecutive patients were included. In all patients, 3D fusion imaging successfully visualized the tantalum helical strands and the closed-cell structure of the nitinol material of the low-profile visualized intraluminal support. A crescent sign was observed in 27.5 % and edge malapposition in 47.5 % of the patients. Malapposition was not significantly associated with location (p = 0.23 crescent sign, p = 0.07 edge malapposition). Almost perfect (κ = 0.88) and substantial (κ = 0.76) agreements between the two raters were found for the detection of crescent signs and edge appositions, respectively. Conclusions: 3D fusion imaging provided clear visualization of the LVIS stent and parent arteries, and could detect malapposition with excellent inter-rater reliability. This technique may provide valuable guidance for surgeons in determining postoperative management.

[Simulation for Endovascular Treatment].

With the advent of high-resolution imaging and advancements in computational fluid dynamics(CFD)and computational structural mechanics(CSM)analyses, clinical simulation of endovascular intervention has gradually become feasible. Virtual stents have become indispensable for coil embolization. For braided stents, such as those with low-profile visualized intraluminal support and flow diverters, predicting postplacement elongation and contraction is challenging; however, software development has enabled more precise treatment planning. Additionally, simulations utilizing three-dimensional(3D)printer models can enable realistic simulations of procedures such as intracranial stents and Woven EndoBridge placement. This approach is beneficial for shunt disorders such as arteriovenous malformations and dural arteriovenous fistulas, offering 3D visualization of shunt access routes and intuitive treatment strategy planning, even for beginners. Furthermore, it can be applied to procedures such as open surgical clipping and nidus resection, aiding in the selection of suitable clips and considerations for ideal resection based on nidus curvature. Simulations using CFD, CSM, and 3D printers are crucial for training surgeons and handling new devices. Harnessing medicine-engineering synergy is essential, and regulatory approval(insurance coverage)and appropriate commercialization of simulations are paramount for the future.

Intermediate catheter use is associated with complete occlusion and dense packing in coil embolization of unruptured cerebral aneurysms: a propensity score matched study.

BACKGROUND: An intermediate catheter (IMC) can improve the maneuverability and stability of the microcatheter. OBJECTIVE: To investigate the efficacy and safety of using an IMC in triaxial systems for coil embolization of unruptured cerebral aneurysms (UCAs). METHODS: A total of 2430 consecutive saccular UCAs (2259 patients) that underwent initial coil embolization at three institutions between November 2003 and May 2023 were retrospectively reviewed. Patients were classified into two groups: with IMC (IMC(+)) and without IMC (IMC(-)). To investigate whether IMC use increased the rate of complete occlusion and the packing density, a propensity score-matched analysis was used to control for clinical, anatomical, and procedural features. RESULTS: Ultimately, 595 (24.5%) coil embolization used an IMC. Propensity score matching was successful for 424 paired IMC(+) and IMC(-) aneurysms. Compared with the IMC(-) group, the IMC(+) group had significantly higher rate of Raymond-Roy Occlusion Classification class 1 immediately after treatment (30.0% vs 20.8%, P=0.003) and at 6 months (28.8% vs 20.0%, P=0.004) and a higher volume embolization ratio (27.2% (SD 6.5%) vs 25.9% (SD 6.2%), P=0.003). Re-treatment rates were not significantly different between the two groups (0.7% vs 0.2%, P=0.624). No significant differences in the incidences of ischemic and hemorrhagic complications and IMC-related parent artery dissection were found between the two groups. CONCLUSION: Use of IMCs in triaxial systems can provide effective and safe support in coil embolization of UCAs because complete occlusion and dense coil packing can be achieved without increased complications.

Diagnostic performance of intraoperative cone beam computed tomography compared with postoperative magnetic resonance imaging for detecting hemorrhagic transformation after endovascular treatment following large vessel occlusion.

OBJECTIVES: Early detection of hemorrhagic transformation (HT) in patients with large vessel occlusion (LVO) after endovascular treatment is important for postoperative patient management. We investigated the diagnostic performance of intraoperative cone beam computed tomography (CBCT) with reference standard magnetic resonance imaging (MRI) for detecting HT. MATERIALS AND METHODS: Consecutive patients with LVO treated by endovascular treatment who underwent intraoperative CBCT and postoperative MRI were included. Two observers evaluated all images for the presence of HT. Sensitivity and specificity for detecting HT were calculated with MRI as reference standard. The observers classified HT according to the European Cooperative Acute Stroke Study (ECASS). Inter-method and inter-rater agreement for the detection of HT and for the ECASS classification were assessed using kappa or weighted Brennan-Prediger (wBP) statistics. RESULTS: Images of 106 procedures (94 for anterior circulation) were analyzed. The sensitivity and specificity for detecting HT on CBCT were 0.77 and 0.83, respectively, for all procedures and 0.83 and 0.8, respectively, for anterior circulation. The inter-method agreement for HT detection (κ = 0.63 overall, κ = 0.69 anterior circulation) and ECASS classification (wBP = 0.67 overall, wBP = 0.77 anterior circulation) were substantial. The inter-rater agreement for HT detection (κ = 0.87 overall, κ = 0.85 anterior circulation) and for ECASS classification (wBP = 0.95 overall, wBP = 0.92 anterior circulation) were almost perfect. CONCLUSIONS: The diagnostic performance of CBCT for the detection of HT in stroke patients treated for LVO was acceptable with excellent inter-rater agreement. Intraoperative CBCT may be useful to trigger early interventions if HT is detected, although detailed classifications of HT may be difficult.

Four-dimensional digital subtraction angiography for exploration of intraosseous arteriovenous fistula in the sphenoid bone.

BACKGROUND: Intraosseous arteriovenous fistula (AVF) is a rare clinical entity that typically presents with symptoms from their effect on surrounding structures. Here, we report a case of intraosseous AVF in the sphenoid bone that presented with bilateral abducens palsy. CASE DESCRIPTION: A previously healthy man presented with tinnitus for 1 month, and initial imaging suspected dural AVF of the cavernous sinus. Four-dimensional digital subtraction angiography (4D-DSA) imaging and a three-dimensional (3D) fused image from the bilateral external carotid arteries revealed that the shunt was in a large venous pouch within the sphenoid bone that was treated through transvenous coil embolization. His symptoms improved the day after surgery. CONCLUSION: This is a case presentation of intraosseous AVF in the sphenoid bone and highlights the importance of 4D-DSA and 3D fused images for planning the treatment strategy.

High-throughput and high-resolution two dimensional mapping of pI and m/z using a microchip in a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer.

We have developed a high-throughput, two-dimensional-mapping (isoelectric point [pI], mass-to-charge ratio [m/z]) method by combining a capillary isoelectric focusing chip sealed with removable resin tape and a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer. Sample proteins are separated in a meandering channel on the chip and immediately frozen. The tape is then removed and the proteins are freeze-dried. The freeze-drying maintains the separation state of the proteins and prevents movement of the sample solution, which can reduce pI resolution. A matrix solution is then applied and mass spectrometry is carried out by laser irradiation. The whole process takes less than 70 min, more than 10 times faster than with two-dimensional, polyacrylamide gel electrophoresis.