Microsurgical approaches to the pulvinar: A comparative analysis.

OBJECTIVE: To compare the area of exposure to the cisternal thalamus associated with four surgical techniques: supracerebellar-infratentorial (SCIT), occipital interhemispheric (OI), transchoroidal (TC) and subtemporal before and after parahippocampal resection (ST and STh, respectively). METHODS: All approaches were performed on both sides of three heads. Qualitative anatomical analyses were performed to understand anatomical limits, advantages, and flaws of each technique. Quantitative analyses for multiple repeated dependent variables assessed significant differences between areas of exposure. RESULTS: Exposure area was significantly more extensive using TC and STh approaches compared to ST, OI, and SCIT. STh achieved a significantly wider exposure compared to ST. Regarding dissection angle, surrounding structures and limitations, ST approaches do not provide adequate exposure, nor alignment with the thalamic axis. The OI and STh may provide a better field of exposure, but without adequate alignment and challenging deeper dissections. TC provides better exposure of the cisternal pulvinar with access to lateral pulvinar at the atrium's anterior wall but is a transcortical route that disrupts non-pathological tissue. SCIT provides an adequate area of exposure with the possibility of alignment with the thalamus axis, thus allowing an easier dissection of deeper lesions. CONCLUSIONS: For lesions at the pulvinar surface, OI and STh are adequate. For lesions restricted to medial pulvinar and deep along the thalamus axis, SCIT approaches are recommended. Lesions extending to the lateral pulvinar and ventricular atrium are best removed through TC approaches. The ST approach was not suitable to the cisternal pulvinar due to its limited angular exposure.

Adjuvant Radiotherapy Did Not Reduce Recurrence of World Health Organization Grade I Meningiomas with Venous Sinus Involvement: A Propensity Score Adjusted Analysis and Literature Review.

BACKGROUND: Most meningiomas are classified as World Health Organization (WHO) grade I. Adjuvant radiation therapy (RT) is commonly recommended for subtotal resections with documented progressive regrowth of lesions with venous sinus involvement. We investigated if recurrence of WHO grade I meningiomas was influenced by adjuvant RT. METHODS: From 2000 to 2014, patients with grade I meningiomas with at least one venous sinus involvement and at least 4 years of follow-up were included. Demographics, venous sinus involvement, histology, and extent of resection (EOR) were characterized. Because patients undergoing RT tend to differ from those for whom adjuvant therapy was not prescribed, we used propensity scores to adjust for confounding variables. RESULTS: Sixty-two patients were included; of these, 18 (29.0%) had recurrences. The mean age was 52.8 ± 12.3 years, and 79.0% were women. A total of 34 cases (54.8%) were submitted to adjuvant RT. Adjuvant RT was more frequent in those who had tumor recurrence (77.8% vs. 45.5%, P = 0.020). RT was more frequent in superior sagittal sinus (SSS) invasion (76.5% vs. 50.0%, P = 0.030) and less prevalent after gross total resection (GTR) (32.4% vs. 67.9%, P = 0.005). Propensity score adjusted analysis suggested no adjuvant RT benefit (odds ratio [OR], 2.51; 95% confidence interval [CI], 0.68-9.28; P = 0.167), independent of the EOR. SSS involvement increased recurrence risk (OR, 12.69; 95% CI, 1.46-110.27; P = 0.021), whereas GTR tended to decrease it (OR, 0.26; 95% CI, 0.06-1.09; P = 0.065). CONCLUSIONS: Adjuvant RT does not seem to be a pivotal criterion to reduce the recurrence rate in patients with grade I meningioma, even when venous sinuses are involved.