Larco, Jorge Luis Arturo

Background Non-acute or chronic subdural hematoma (cSDH) is commonly treated with surgical evacuation followed by middle meningeal artery embolization (MMAe). This two step approach increases procedural complexity and redundancy, hospitalization duration, and patient risk. We hypothesized that cSDH could be managed through a single session endovascular procedure and conducted a multimodal preclinical study to evaluate feasibility. Methods We performed three-dimensional heat mapping of hematoma distribution from preoperative CT scans (n=69) and analyzed middle meningeal artery (MMA) and superior sagittal sinus (SSS) anatomy and perforation trajectories using imaging from 107 patients. Rheological properties of 41 SDH samples were assessed using hybrid rheometry and modeled with the Carreau equation. Aspiration feasibility was tested using a 0.027 inch microcatheter (n=16), and dura perforation forces were quantified with a 28 G needle in fresh cadaveric dura (n=10). Results Heat mapping localized cSDH to the parietal convexities (>80% probability) under the branches of the MMA, with limited midline involvement and proximity to the SSS (<10%). The posterior division of the MMA (diameter 1.23±0.23 mm) accommodated a 0.027 inch microcatheter in >90% of cases, with perforation trajectories targeting high probability hematoma zones in 105 of 107 cases. SDH samples exhibited shear thinning viscosity ( η ₀ =172 mPa×s, η ∞ =2.78 mPa×s), with mean aspiration times of 1.21±0.54 min per 10 mL. Perforation forces averaged 0.68±0.24 N in normal and 1.29±0.48 N in calcified dura (P=0.05). Conclusion Anatomical, rheological, and biomechanical data from this study support the feasibility of endovascular drainage of cSDH through the MMA.

Objectives: The development and evaluation of percutaneous thrombectomy devices for pulmonary embolism (PE) pose a need for standardized large in vivo models with representative anatomical and physiological conditions and clots analogs. In this study, we present a swine model of PE model employing human-derived clot analogs. Material and Methods: Baseline angiographic and physiological pressure measurements were obtained in six adult Yorkshire pigs (45–65 kg) and results were benchmarked for interspecies comparison with published human data using fluoroscopic examinations, intra-arterial pressure measurements, and histologic studies. Then, clot analogs were created ex vivo employing banked human blood and a subset incubated in iodinated contrast for fluoroscopic visualization. Clot analogs were then embolized via a femoral venous access and angiographic/physiological consequences were evaluated. Results: The main, right, and left pulmonary artery diameters were 24 ± 1.1 mm, 16.5 ± 0.8 mm, and 12.6 ± 1.2 mm, respectively. The angle between the main pulmonary artery at the bifurcation point was approximately 90–95°. The clot analogs were heterogeneous and had increased fibrin content along the clot length. The overall composition was 96.63% red blood cell (RBC)/3.37% fibrin in the initial section, 48.85% RBC/51.15% fibrin in the intermediate section, and 3.44% RBC/96.56% fibrin in the final section. Embolization of the clot analogs resulted in distal occlusion of the right and left pulmonary arteries. Conclusions: This swine model coupled with clot analog is able to accurately mimic human anatomical and physiological conditions in PE making it feasible for the evaluation of pulmonary thrombectomy devices.