gms | German Medical Science

Objective: The goal of the retrospective study is the evaluation of risk factors for postoperative neurological deficits after petroclival meningioma (PCM) surgery with special focus on standard craniotomies.

Methods: One-hundred-twenty-three tumor surgeries were performed in 111 patients with primary and recurrent PCM using a retrosigmoid (n=104) or a subtemporal/ pterional (n=19) approach. The postoperative course was analysed according to a new 4-grade classification system, based on tumor specific features (consistency, surface, arachnoid cleavage, localization). Patient specific factors (age, gender) and tumor specific factors were evaluated with respect to pre- and postoperative cranial nerve (CN) deficits, gross total resection, morbidity and mortality.

Results: For the analysis of the extent of resection the data of the whole group was available. In type I tumor patients (n=56, soft tumor consistency, smooth surface, plane arachnoid cleavage, and unilateral localization), gross total resection (GTR) was achieved in 76.8%, whereas in type IV patients (n=17, firm tumor consistency, bilateral localization, with smooth or cauliflower surface, and w/ or w/o arachnoid cleavage) GTR was only possible in 35.3%. The difference in resectability between the type I group and all others (n=67) was significant (p=0.002). Influential features for resection were tumor consistency (p<0.001), size (p=0.009) and cavernous sinus infiltration (p<0.001). For the analysis of postoperative cranial nerve deficits, the data of 112 tumor surgeries in 101 patients were available (96 retrosigmoid and 16 subtemporal/ pterional approach). The best outcome was observed in type I tumor patients (n=54) with 11.1% new CN deficits in comparison to all others (n=58) with 36.2% (p=0.008). Factors associated with a better cranial nerve outcome were tumor consistency (p = 0.038) and tumor location (p = 0.016). The morbidity and mortality rates for the whole group were 15.3% and 1.8%, respectively.

Conclusion: Standard craniotomies as the retrosigmoid or subtemporal/pterional approaches are suitable in most of the PCM cases. Besides tumor location, the genuine tumor specific features determine the resectablility of the tumor and the outcome of the patients.