{Reference Type}: Journal Article
{Title}: Novel classification of foramen magnum meningiomas predicted by topographic position relative to neurovascular bundle.
{Author}: Gattozzi DA;Erginoglu U;Khanna O;Hosokawa PW;Martinez-Perez R;Baskaya MK;Youssef AS;
{Journal}: Acta Neurochir (Wien)
{Volume}: 166
{Issue}: 1
{Year}: 2024 Apr 30
{Factor}: 2.816
{DOI}: 10.1007/s00701-024-06091-1
{Abstract}: <B>OBJECTIVE: </B>Proximity to critical neurovascular structures can create significant obstacles during surgical resection of foramen magnum meningiomas (FMMs) to the detriment of treatment outcomes. We propose a new classification that defines the tumor's relationship to neurovascular structures and assess correlation with postoperative outcomes.<BR><B>METHODS: </B>In this retrospective review, 41 consecutive patients underwent primary resection of FMMs through a far lateral approach. Groups defined based on tumor-neurovascular bundle configuration included Type 1, bundle ventral to tumor; Type 2a-c, bundle superior, inferior, or splayed, respectively; Type 3, bundle dorsal; and Type 4, nerves and/or vertebral artery encased by tumor.<BR><B>RESULTS: </B>The 41 patients (range 29-81 years old) had maximal tumor diameter averaging 30.1 mm (range 12.7-56 mm). Preoperatively, 17 (41%) patients had cranial nerve (CN) dysfunction, 12 (29%) had motor weakness and/or myelopathy, and 9 (22%) had sensory deficits. Tumor type was relevant to surgical outcomes: specifically, Type 4 demonstrated lower rates of gross total resection (65%) and worse immediate postoperative CN outcomes. Long-term findings showed Types 2, 3, and 4 demonstrated higher rates of permanent cranial neuropathy. Although patients with Type 4 tumors had overall higher ICU and hospital length of stay, there was no difference in tumor configuration and rates of postoperative complications or 30-day readmission.<BR><B>CONCLUSIONS: </B>The four main types of FMMs in this proposed classification reflected a gradual increase in surgical difficulty and worse outcomes. Further studies are warranted in larger cohorts to confirm its reliability in predicting postoperative outcomes and possibly directing management decisions.