Simple rigid skull base reconstruction with resorbable unsintered hydroxyapatite/poly-l-lactide plate in endoscopic endonasal skull base tumor surgery: illustrative case.

Background: Skull base reconstruction following an extended endoscopic endonasal approach (EEA) is essential for preventing postoperative CSF leakage. Despite recent advancements in surgical techniques and materials, CSF leakage remains a significant complication. This report presents a rigid reconstruction technique utilizing a resorbable unsintered hydroxyapatite/poly-l-lactide (u-HA/PLLA) plate to reduce postoperative CSF leakage.

Observations: Between May 2024 and June 2025, this method was used in 10 cases of extended EEA involving high-flow intraoperative CSF leaks and bone defects more than 25 mm. Notably, no postoperative CSF leakage was observed following the introduction of the u-HA/PLLA plate.

Lessons: This material offers a unique combination of flexibility and mechanical strength comparable to cortical bone, along with osteoconductivity and bioresorbability, while producing negligible interference on postoperative imaging. These properties make it a highly promising material for skull base reconstruction. https://thejns.org/doi/10.3171/CASE25544.