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A 60-year-old woman on active surveillance for an olfactory groove meningioma turned to surgeons at �ٺ���Ƶ when her tumor began to enlarge. Combining their expertise, a multidisciplinary surgical team undertook a challenging endonasal approach to successfully resect the patient’s tumor while simultaneously preserving her sense of smell.

Active Surveillance Informs a Minimally Invasive Approach

Surgery for the patient’s large posterior fossa meningioma four years prior had incidentally revealed an olfactory groove meningioma less than a centimeter in diameter. These benign tumors, characterized by indolent growth along the olfactory nerve, are typically identified only once symptoms develop. The early discovery of this tumor combined with active surveillance, enabled timely surgical intervention once the tumor began to enlarge.

Although the complete extirpation of a low-grade meningioma with its dural attachment is desirable, the success of this more invasive surgery can be limited by the proximity of critical structures and the risk of permanent neurological damage, making less invasive procedures preferable despite having their own intraoperative challenges.

“An open craniotomy or a minimally invasive transorbital approach could have been pursued, but both options were potentially disfiguring and obviously disruptive,” explains Donato R. Pacione, MD, assistant professor in the . “We wanted to use an approach that would avoid manipulating the frontal lobes of the brain or risking cosmetic disfiguration.”

Dr. Pacione and Seth M. Lieberman, MD, assistant professor in the , planned to resect the meningioma using a challenging, and rarely attempted, minimally invasive endoscopic single-nostril endonasal approach. The physicians leveraged their individual expertise to develop a plan that would allow them to navigate intraoperative obstacles and also avoid the contralateral olfactory nerve—which was essential to achieving complete resection while preserving the patient's olfactory sensation.

Single-Nostril Approach Results in Complete, Complication-Free Resection

Dr. Lieberman began the procedure in the right nasal cavity. The middle turbinate was resected and then a maxillary antrostomy and a sphenoethmoidectomy were performed, followed by a Draf IIB frontal sinusotomy to obtain anterior exposure to the anterior cranial fossa. An extended nasoseptal flap was then harvested and placed in the nasopharynx for later use. The mucosa of the olfactory cleft was dissected back to the first olfactory fiber, revealing the tumor coming through one of the olfactory foramina.

Dr. Pacione continued at this point, first dividing the anterior ethmoidal artery and then exposing the dura, in front of and posterior to the tumor borders. He was then able to incise the dura and remove the dural leaflet, exposing the tumor and its interface with the brain. Initial portions were dissected and removed in piecemeal fashion, and then the remaining tumor was removed en bloc through the cribriform plate after medial dissection.

After confirmation of negative margins, Dr. Lieberman proceeded with multilayered reconstruction of the skull base.

Preserved Function with Tumor Excision Critical to Successful Outcome

This advanced approach, made possible through shared surgical experience, achieved complete resection of the tumor with minimal trauma to other tissues and simultaneously preserved olfactory function. This was confirmed 3 weeks postoperatively with a smell identification test whose score matched the patient’s preoperative score of 33 out of 40.

Although advances in fiber optic technology, endoscopic instrumentation, and intraoperative navigation have helped advance minimally invasive skull base tumor resection techniques, successful implementation of these techniques requires finely tuned surgical collaboration and well-honed expertise. “When you’re working in a tight space with two instruments and a camera, a coordinated approach is critical for success,” notes Dr. Lieberman. “Our ongoing collaboration creates a natural confluence of shared judgment and expertise—and, in this case, enabled an approach that minimized complications and resulted in a successful outcome.”