Introduction: Atrial intraventricular meningiomas are relatively rare tumors that often mandate
surgical resection. Microsurgical resection with the operative microscope is the mainstay
of treatment; however, over the past decade the use of an exoscope and navigable channel
retractor has facilitated a less invasive alternative of tumor access and resection.
As this is a newer technology, the case selection and indications for channel-based
intraventricular surgery are not yet well defined. We present a comparative case series
of seven intraventricular meningiomas of the atrium/trigone that underwent either
complete microscopic or exoscopic approach to understand patient or tumor features
lending themselves to open versus channel-based approach selection.
Methods: Retrospective data was collected on all meningioma surgeries performed by a single
surgeon at our institution. Inclusion criteria were adult patients with atrial meningiomas
operated on between January 1, 2012, and August 1, 2022. Demographic information,
symptomatology, surgical approach and outcome, pre- and post-operative MRI imaging,
pathology results, and post-operative clinical course were collected and reviewed.
Results: Of a total of 211 meningioma cases, 7 atrial intraventricular meningiomas were identified
and analyzed ([Table 1]). All patients were female. Three patients underwent exoscopic channel-based resection
and four underwent conventional open trans-sulcal microscopic resection. Patients
who underwent exoscopic channel-based resection were younger (45 vs. 54 years) and
had a shorter postoperative length of stay (3.3 vs. 5.8 days). Gross total resection
was achieved in all 7 cases regardless of approach method. Two patients developed
transient homonymous hemianopsia and two developed transient mixed aphasia, all with
significant improvements of these symptoms within one month upon re-evaluation in
the clinic.
Meningiomas were WHO grades I versus II. No recurrences were identified over the follow-up
period. Tumors that underwent exoscopic resection were smaller in diameter on average
(2.9 vs. 5.2 cm) and were deeper (2.5 vs. 1.1 cm; [Fig. 1], [Fig. 2]).
Discussion/Conclusion: The surgical management of atrial meningiomas remains mainly microsurgical, especially
for larger tumors approaching the cortical surface. In selected patients with smaller
and deeper-situated tumors, however, an exoscopic channel-based approach provides
sufficient exposure to achieve complete resection, potential reduction of collateral
injury to normal brain, and improved surgeon ergonomics. In our study, patients who
underwent exoscopic resection had smaller tumors and had an overall shorter length
of stay in the hospital. The small sample size and heterogenous population limits
the ability to make statistical comparisons; however, both traditional microsurgical
and emerging exoscopic approaches are effective and safe surgeries for resection of
atrial meningiomas.
Figure 1 Pre- and postoperative MRI of exoscopic patients.
Figure 2 Pre- and postoperative MRI of microscopic patients.
