Majchrzak H

The assessment of prognostic factors in surgical treatment of low-grade gliomas: A prospective study

OBJECTIVEnA prospective volumetric analysis of extent of resection (EOR) was carried out to assess surgical outcomes in adults diagnosed with hemispheric low grade gliomas (LGGs).nnnMATERIALS AND METHODSn68 consecutive patients diagnosed with LGGs were enrolled in the study. Pre- and post-operative tumor volumes and EOR were measured based on FLAIR MRI. Dynamic susceptibility contrast perfusion magnetic resonance imaging (DSC MRI) was used for the assessment of relative cerebral blood volume (rCBV). Three outcome measures were assessed: overall survival (OS), progression-free survival (PFS), and malignant degeneration-free survival (MFS).nnnRESULTSnIn 6 (9%) patients permanent neurologic deficits were observed. No statistically significant dependence between the EOR and the occurrence of permanent deficits was found. The eloquent or close to the eloquent location was statistically connected with lower EOR (p=0.023). The preoperative volume of tumors treated with gross total resection was significantly smaller than the volume of tumors in subtotal or partial resection groups (p=0.020, p<0.001, respectively). OS was predicted by age at diagnosis (p=0.032), and rCBV (p=0.002). Progression and malignant transformation occurred in 22 (32%) and 11 (16%) out of 68 patients. PFS was predicted by preoperative tumor volume (p=0.005), postoperative tumor volume (p=0.008), the EOR (p=0.001), and by the rCBV (p=0.033). MFS was predicted by preoperative tumor volume (p=0.034), the EOR (pp=0.020), and by rCBV (p=0.022). Postoperative tumor volume was associated with a trend of improved MFS (p=0.072). The univariate analysis shows the statistical trend for the relationship between histological subtype and PFS and MFS (p=0.079, p=0.078, respectively). Multivariate analysis selected preoperative tumor volume and rCBV as independently associated with PFS (p=0.009, p=0.019, respectively) and MFS (p=0.023, p=0.035, respectively). EOR was associated with a trend of improved PFS, and MFS (p=0.069, p=0.094, respectively).nnnCONCLUSIONSnTumor resection of LGG with the use of intraoperative monitoring and neuronavigation is associated with a low risk of new permanent deficits, but EOR significantly decreases with the size of the tumor and/or its location in/close to the eloquent areas. Smaller preoperative tumor volume and greater EOR are significantly associated with longer OS, PFS and MFS. Preoperative rCBV is one of the important prognostic factors significantly connected with survival. Prognosis in LGGs is still under discussion. Other factors such as age, histopathological subtype and KPS should not be underestimated.

Transcranial color-coded Doppler assessment of cerebral arteriovenous malformation hemodynamics in patients treated surgically or with staged embolization

OBJECTIVEnThe etiology of hemodynamic disturbances following embolization or surgical resection of arteriovenous malformations (AVMs) has not been fully explained. The aim of the study was the assessment of the selected hemodynamic parameters in patients treated for cerebral AVMs using transcranial color-coded Doppler sonography (TCCS).nnnMATERIALS AND METHODSnForty-six adult patients (28 males, 18 females, aged 41 ± 13 years, mean ± SD) diagnosed with AVMs who were consecutively admitted to the Department of Neurosurgery between 2000 and 2012 treated surgically or with staged embolization were enrolled in the study. All patients were examined with TCCS assessing mean flow velocity (Vm), the pulsatility index (PI) and vasomotor reactivity (VMR) in all main intracranial arteries. The examined parameters were assessed in the vessel groups (feeding, ipsilateral and contralateral to the AVM) and they were compared between the examinations, i.e. at admission, within 24h after the first embolization or surgical resection (I control), and before the second embolization (II control).nnnRESULTSnIn feeders which were completely obliterated or surgically resected--I control examination showed a nonsignificant Vm decrease. The difference between Vm before embolization and II control examination was significant (102.0 ± 47.8 cm/s vs 54.3 ± 19.4 cm/s, p<0.01). A significant increase in PI (0.72 ± 0.18 vs 0.94 ± 0.24, p<0.01) and VMR (1.80 ± 0.59 vs 2.78 ± 0.78, p<0.01) of feeding vessels was observed in I control. No further increase in PI or in VMR was observed. In embolized feeding vessels after partial AVM embolization I control examination showed a significant decrease in Vm (116.1 ± 32.6 cm/s vs 93.4 ± 33.0 cm/s, p<0.01). No further significant decrease in Vm was noted. The pulsatility index increased significantly (I control, 0.54 ± 0.11 vs 0.66 ± 0.15, p<0.01) and then decreased nonsignificantly (II control). No statistically significant differences were found in VMR values between pretreatment, I and II control examinations. Both Vm in the ipsilateral internal carotid artery and the ratio of Vm of the embolized vessel to Vm of the corresponding contralateral vessel were significantly higher in I control examination compared to II control examination (111.8 ± 44.0 cm/s vs 101.3 ± 40.6 cm/s, p<0.01; 1.63 ± 0.61 vs 1.37 ± 0.62, p<0.01; respectively). No statistically significant correlation was observed between the decrease in Vm or the increase in PI in the embolized vessels and the reduction of AVM volume. In the nonembolized feeding vessels after partial AVM embolization II control examination revealed the increase in Vm and a significant decrease in PI (0.71 ± 0.21 vs 0.62 ± 0.16, p<0.01) compared to I examination. No statistically significant changes in the VMR value in the nonembolized feeders between the pretreatment, I and II control examinations were noted.nnnCONCLUSIONSnThe decrease in Vm and the increase in the PI in the embolized feeding vessels after the first complete embolization or surgical resection is observed, whereas the PI returned to normal values before Vm does. The observed decrease in Vm and an increase in the PI in embolized AVM feeders after complete or partial embolization do not correlate with the extent of embolization. In these vessels a relative increase in blood flow velocity is maintained within the first 24h following embolization as compared to contralateral vessels. The increase in Vm is not related to disturbances in VMR. Blood redistribution to the nonembolized AVM feeders is observed after partial AVM embolization.

Surgical treatment of adult patients with thalamic tumors with the aid of tractography, fMRI, transcranial electrical stimulation and direct electrical stimulation of the subcortical white matter

The aim of investigation was to assess treatment outcomes in adult patients with thalamic tumors, operated on with the aid of tractography (DTI) and monitoring of motor evoked potentials (MEPs) generated due to transcranial electrical stimulation (TES) and direct electrical stimulation (DES) of the subcortical white matter. 38 subsequent patients with thalamic tumors were operated on using tractography (DTI)-integrated neuronavigation, transcranial electrical stimulation (TES) and direct electrical stimulation (DES). The volumetric method was used to calculate pre- and postoperative tumor volume. Total tumor resection (100%) was performed in 18 (47%) patients, subtotal in 9 (24%) (mean extent of resection -89.4%) and partial in 11 (29%) patients (mean extent of resection -77.18%). The mean extent of resection for all surgical patients was 86.5%. Two (5.2%) patients died postoperatively. Preoperative hemiparesis was present in 18 (47%) patients. Postoperative hemiparesis was observed in 11 (29%) patients of whom only in 5 (13%) new paresis was noted due to surgical intervention. In patients with hemiparesis significantly more frequently larger tumor volume was detected preoperatively. Low mean normal fractional anisotropy (nFA) values in the internal capsule were observed statistically significantly more frequently in patients with preoperative hemiparesis as compared to the internal capsule of the unaffected hemisphere. Transcranial electrical stimulation helps to predict postoperative paresis of extremities. Direct electrical stimulation is an effective tool for intraoperative localization of the internal capsule thus helping to avoid postoperative deficit. In patients with tumor grade I and II the median time to tumor progression was 36 months. In the case of patients with grades III and IV it was 14 months. The median survival time in patients with grades I and II it was 60 months. In patients with grades III and IV it was 18 months. Basing on our results, patients with glioma grade I/II according to WHO classification are the best candidates for surgical treatment of thalamic tumors. In this group of the patients more often resection is radical, median time to progression and survival time are longer than in patients with gliomas grade III and IV. Within a 7-year follow-up none of the patients with GI/GII grade glioma died.