Vascularized Temporoparietal Fascial Flap: A Novel Surgical Technique to Bypass the Blood-Brain Barrier in Glioblastoma.

Background: The major difficulty in treating glioblastoma stems from the intrinsic privileged nature of the brain. This complicates therapy, as many traditionally potent chemotherapeutics cannot access their target sites in the brain. Several techniques have been investigated to overcome this barrier and facilitate drug delivery. However, these techniques have inherent shortcomings related to the delivery system, the drug itself, or its bioactivity. Periosteal flaps and temporoparietal fascial flaps (TPFFs) are widely used options because they have predictable vasculature and a wide rotational arc. These flaps are not restricted by the blood-brain barrier, as they derive their vascular supply from branches of the external carotid artery, which can be readily identified with Doppler ultrasound. We hypothesized that transposition of a vascularized TPFF to the walls of a resected tumor surgical cavity may bring autologous tissue not restricted by the blood-brain barrier in close vicinity of the resected tumor bed microenvironment. This offers a nonselective, long-lasting gateway to target the residual tumor cells nesting in the brain adjacent to the tumor.

Case Description: A 47-year-old, right-handed woman with newly diagnosed multifocal glioblastoma underwent excision of the tumor and TPFF placement. This illustrative case report represents the first case of the use of this novel surgical technique with radiologic follow-up.

Conclusions: The blood-brain barrier is identified as a major barrier for effective drug delivery in glioblastoma. This study demonstrates the feasibility of the TPFF technique to bypass this barrier and help facilitate the goal of improving drug delivery.