Objective: Cerebellopontine angle (CPA) meningiomas present unique challenges given their anatomical
location and proximity to critical neurovascular structures. Postoperative complications
and persistent symptoms can debilitate patients, but our ability to predict their
occurrence and long-term rates of recovery remain uncharacterized. This study examines
the clinical presentation, surgical management, and postoperative outcomes of CPA
meningiomas.
Materials and Methods: We conducted a retrospective cohort study of CPA meningioma cases resected at Mass
General Brigham (2006–2020) using descriptive statistics and univariate/multivariate
logistic regression to identify predictors of progression or recurrence.
Results: The total cohort was 95 patients (median age: 59.1 years, 82.1% female sex), reflecting
2.8% of meningioma resections at our institutions across the study period. Preoperative
symptoms most commonly included hearing loss (49.5%), ataxia (42.1%), and headaches
(29.5%). Surgical approaches included the retrosigmoid (78.9%), transmastoid retrosigmoid
(17.9%), and middle fossa (3.2%) approaches, with gross total resection (GTR) achieved
in 62.1% of patients. Smaller tumor size (t = 3.17, p = 0.002) was a predictor of GTR (see [Fig. 1]). For tumors with demonstrated intracanalicular invasion, drilling into the canal
was significantly associated with GTR (χ2 = 21.8, p < 0.001). Specifically, the IAC was drilled in 26 patients with 88.5% of these resections
achieving GTR, while 17 tumors with intracanalicular invasion did not have drilling
of the IAC and achieved GTR in only 2 cases. In most cases, the cranial nerve VII/VIII
complex was inferior (45.6%) or superior (19.1%) to the meningioma, with a smaller
proportion being anterior (5.9%), posterior (13.2%), or other (16.2%). Postoperative
hearing loss was stable or improved in the majority of patients at final clinical
follow-up (see [Fig. 2]). Overall, progression or recurrence of meningioma was observed in 25.3% of patients
at a median time-to-progression of 3.00 years (IQR: 2.91 years) and 1.59 years (IQR:
2.80 years) for WHO Grade 1 and Grade 2 tumors respectively. GTR (OR: 0.13, p = 0.002) and older age per year (OR: 0.94, p = 0.002) were associated with lower odds of progression or recurrence on multivariable
testing.
Fig. 1 Box plot comparing maximum tumor diameter in cm across cases in which subtotal or
gross total resections were achieved. Box plot reflects the median maximum diameter
with edges at the first and third quartiles. Upper and lower whiskers were calculated
as +/− 1.5 (IQR).
Fig. 2 Summary of reported hearing loss outcomes in 31 patients across the immediate post-operative
period, first clinical follow up (median: 1.1 months), and final clinical follow-up
(median: 39.4 months). Of the 47 patients presenting with preoperative hearing loss,
only 31 reported data at all three chosen time-points.
Conclusion: Achieving GTR is important for CPA meningiomas to achieve optimal symptomatic control
and reduced progression and recurrence rates. Further, drilling of the IAC is an important
predictor of achieving GTR particularly in tumors with intracanalicular invasion.
