Dural Substitutes Differentially Interfere with Imaging Quality of Sonolucent Transcranioplasty Ultrasound Assessment in Benchtop Model

Background: Sonolucent cranioplasty implants were recently introduced into clinical practice and tested for use with transcranioplasty ultrasound (TCUS). In situations where dural substitutes (DSs) are needed during closure, such as in extracranial-intracranial bypass, it is unclear if the DS influences the imaging quality of TCUS. The aim of this study was to assess the influence of DSs on imaging quality during TCUS assessment with sonolucent cranioplasty. Methods: A tofu vascular brain model was constructed with a ClearFit implant in between 2 layers of tofu. Injection of saline solution through a 6-F Envoy DA XB endovascular catheter (6-F Envoy DA XB) inserted into the deeper tofu layer mimicked an intracranial vessel. TCUS image quality, including Doppler, with 4 different DSs (DuraGen, Durepair, DuraMatrix-Onlay, DuraMatrix Suturable) placed under the cranioplasty was compared against a control by 2 examiners. A literature search of MEDLINE and EMBASE was conducted to find previous reports of acoustic properties of DSs. Results: TCUS assessment including Doppler was feasible with the model in longitudinal and axial planes, and the pulsatile particle injection was visualized in real time. DuraGen and Durepair showed Doppler quality and picture detail comparable to the control, while the DuraMatrix-Onlay and DuraMatrix Suturable were inferior to the control. The literature search yielded only 1 previous report on acoustic properties of DSs. Conclusions: DSs interfere differentially with imaging quality during TCUS assessment. However, these results are based on a benchtop model and need to be further assessed in the clinical setting.