Evaluation of an in vivo preclinical model for human middle meningeal artery embolization using the posterior intercostal artery of the swine

Embolization of Middle Meningeal Arteries for Symptomatic Subacute Subdural Hematoma in Patients with Cancer

PURPOSE

The purpose of this study was to evaluate the technical and clinical success of middle meningeal artery (MMA) embolization performed for symptomatic subacute subdural hematoma (SDH) in patients with cancer.

METHODS

This study retrospectively included 23 consecutive patients (12 men, 11 women; median age 61 years, interquartile range: 55.5-75.5) who underwent 34 MMA angiograms for symptomatic SDH in 2022 and 2023. Median SDH thickness was 10.5 mm (7-12). Median platelet count was 117 K/mcL (54.5-218). 10 patients (43.5%, 10/23) had hematologic malignancies, seven patients (30.4%, 7/23) had surgery. Fluoroscopy time (FT), reference dose (RD), and kerma area product (Kap) were analyzed. Adverse events and outcomes were recorded.

RESULTS

The median imaging and clinical follow-up were 65 days (36.5-190.5) and 163 days (86-274), respectively. The technical success rate was 91.2% (31/34) as three MMA were not identified in two patients. Median procedure duration was 61 min (55.5-75.5). Median FT was 21.6 min (15.5-31.8); median RD was 158 mGy (96-256); and median Kap was 32.9 Gy.cm2 (20.4-45.1). No further intervention was needed. For 16 patients, SDH resolved after in median 59.5 days (50-90). For seven patients, SDH remained visible on the last imaging follow-up performed at 24 days in median (6.5-36.5). No predictive factor of failure was identified. The adverse event rate was 1/23 (4.3%). Eight patients (34.8%, 8/23) died during follow-up from progression of cancer.

CONCLUSION

MMA embolization of symptomatic SDH in patients with cancer appears safe and is associated with improvement in clinical symptoms.

A novel swine model of selective middle meningeal artery catheterization and embolization

BACKGROUND

Middle meningeal artery (MMA) embolization is a promising intervention as a stand-alone or adjunct treatment to surgery in patients with chronic subdural hematomas. There are currently no large animal models for selective access and embolization of the MMA for preclinical evaluation of this endovascular modality. Our objective was to introduce a novel in vivo model of selective MMA embolization in swine.

METHODS

Diagnostic cerebral angiography with selective microcatheter catheterization into the MMA was performed under general anesthesia in five swine. Anatomical variants in arterial meningeal supply were examined. In two animals, subsequent embolization of the MMA with a liquid embolic agent (Onyx-18) was performed, followed by brain tissue harvest and histological analysis.

RESULTS

The MMA was consistently localized as a branch of the internal maxillary artery just distal to the origin of the ascending pharyngeal artery. Additional meningeal supply was observed from the external ophthalmic artery, although not present consistently. MMA embolization with Onyx was technically successful and feasible. Histological analysis showed Onyx material within the MMA lumen.

CONCLUSIONS

Microcatheter access into the MMA in swine with liquid embolic agent delivery represents a reproducible model of MMA embolization. Anatomical variations in the distribution of arterial supply to the meninges exist. This model has a potential application for comparing therapeutic effects of various embolic agents in a preclinical setting that closely resembles the MMA embolization procedure in humans.