Background: There have been major developments in diagnostic and surgical and non-surgical techniques used in the management of meningiomas over last three decades. We set out to describe these changes in a systematic manner.
Method: Clinical and radiological data, surgical procedures, complications, and outcome of 817 patients who underwent surgery for primarily diagnosed meningioma between 1991 and 2015 were investigated.
Results: Median age at diagnosis increased significantly from 56 to 59 years (p = .042), while tumor location and preoperative Karnofsky performance status did not change during the observation period. Availability of preoperative MRI increased, and rates of angiography and tumor embolization decreased (p < .001, each). Median duration of total, pre-, and postoperative stay was 13, 2, and 9 days, respectively, and decreased between 1991 and 2015 (p < .001, each). Median incision-suture time varied annually (p < .001) but without becoming clearly longer or shorter during the entire observation period. The use of intraoperative neuronavigation and neuromonitoring increased, while the rates of Simpson grade I and III surgeries decreased (p < .001). Rates of postoperative hemorrhage (p = .997), hydrocephalus (p = .632), and wound infection (p = .126) did not change, while the frequency of early postoperative neurological deficits decreased from 21% between 1991 and 1995 to 13% between 2011 and 2015 (p = .003). During the same time, the rate of surgeries for postoperative cerebrospinal fluid leakage slightly increased from 2 to 3% (p = .049). Within a median follow-up of 62 months, progression was observed in 114 individuals (14%). Progression-free interval did not significantly change during observation period (p > .05). Multivariate analyses confirmed the lack of correlation between year of surgery and tumor relapse (HR: 1.1, p > .05).
Conclusions: Preoperative diagnosis and surgery of meningiomas have been substantially evolved. Although early neurological outcome has improved, long-term prognosis remains unchanged.
Keywords: Evolution; Meningioma; Microsurgery; Outcome; Prognosis.