Stereotactic anatomy of the third ventricle.

PURPOSE: Endoscopic third ventriculostomy (ETV) is a surgical procedure that can lead to complications and requires detailed preoperative planning. This study aimed to provide a more accurate understanding of the anatomy of the third ventricle and the location of important structures to improve the safety and success of ETV. METHODS: We measured the stereotactic coordinates of six points of interest relative to a predefined stereotactic reference point in 23 cadaver brain hemi-sections, 200 normal brain magnetic resonance imaging (MRI) scans, and 24 hydrocephalic brain MRI scans. The measurements were statistically analyzed, and comparisons were made. RESULTS: We found some statistically significant differences between genders in MRIs from healthy subjects. We also found statistically significant differences between MRIs from healthy subjects and both cadaver brains and MRIs with hydrocephalus, though their magnitude is very small and not clinically relevant. Some stereotactic points were more posteriorly and inferiorly located in cadaver brains, particularly the infundibular recess and the basilar artery. It was found that all stereotactic points studied were more posteriorly located in brains with hydrocephalus. CONCLUSION: The study describes periventricular structures in cadaver brains and MRI scans from healthy and hydrocephalic subjects, which can guide neurosurgeons in planning surgical approaches to the third ventricle. Overall, the study contributes to understanding ETV and provides insights for improving its safety and efficacy. The findings also support that practicing on cadaveric brains can still provide valuable information and is valid for study and training of neurosurgeons unfamiliar with the ETV technique.

Neurosurgical anatomy of the floor of the third ventricle and related vascular structures.

PURPOSE: Anatomical knowledge of the floor of the third ventricle (FTV) is essential in avoiding surgical complications during endoscopic third ventriculostomy. The purpose of this study was to characterize the morphometry of FTV and related arteries, particularly the basilar artery (BA), as well as the factors that influence it. METHODS: Twenty-six formalin-fixed adult brains and two hundred adult brain MRIs were studied focusing on FTV and related arteries. Dimensions of interest were measured using image analysis software. Morphometric data obtained were statistically analysed. RESULTS: Distances between FTV, intermammillary sulcus (IMS), infundibulum, BA bifurcation, and posterior communicating arteries (PCoAs) were described on the cadavers and the MRIs. Distance between right and left PCoAs was greater at their anterior extremity (p < 0.001). Right PCoA was longer (p = 0.016). BA was lateralized in 58.4% of cases and its calibre was larger in males (p < 0.001). The distance from BA apex to FTV was inversely correlated with BA diameter (p < 0.001) and age (p = 0.004). Distance from IMS to infundibulum and the distance between both PCoAs were greater in MRI series when compared to cadaver series (p < 0.001). CONCLUSIONS: A quantitative description of the morphometry of the region of the FTV and related vessels was obtained, helping neurosurgeons in planning their surgical approach. The distance from BA apex to FTV was shorter in individuals with larger BA calibre and in older subjects. MRI studies were qualitatively superior to cadaveric studies in evaluating the anatomy of this region.

The role of periodontal treatment associated with photodynamic therapy on the modulation of systemic inflammation in the experimental model of asthma and periodontitis.

BACKGROUND: The association of Periodontitis (P) with several systemic diseases, among them asthma (A), has been previously studied. As periodontal treatment (TTO) associated with photodynamic therapy (PDT) is able to treat P, the aim of this study is to verify whether periodontitis exerts systemic effects on asthma, and whether TTO, associated or not with PDT, is capable of altering the systemic course of both pathologies. METHODS: 64 male Balb/c mice were divided into 8 groups (n = 8): Basal (B), P, P + TTO, P + TTO + PDT, Asthma, A + P, A + P + TTO, A + P + TTO + PDT. After 43 days, all animals were euthanized. The total and differential leukocyte count in serum, platelet count, alveolar bronchial lavage cell count, femoral lavage cell count in addition to the reactivity of the trachea, lung edema and gingiva cytokines were analyzed. The frequency of inflammatory cells was assessed via flow cytometry. One-way ANOVA test was used, followed by the Student-Newman-Keuls post-test. RESULTS: There was an increase in the number of blood circulating eosinophils in group A when compared to group B (p < 0.01); this characterized the asthma experimental model. P (p < 0.05) presented a lower amount of cytokine TNF-α in the gingiva when compared to the Asthma group. Apart from that, there was no statistical difference found for the other analyzed parameters. CONCLUSION: These data contributed to elucidate that P and A, associated or not with TTO and PDT, are not able to interfere with the systemic parameters of Balb/c mice.

Biochemical control of prostate cancer with iodine-125 brachytherapy alone: experience from a single institution.

AIM: Brachytherapy is an adequate option as monotherapy for localised prostate cancer. The objective of this study was to evaluate and compare biochemical failure free survival (BFFS) after low-dose-rate brachytherapy (LDRB) alone for patients with prostate cancer using ASTRO and Phoenix criteria, and detect prognostic factors. METHODS: Data on 220 patients treated between 1998 and 2002 with LDRB were retrospectively analysed. Neoadjuvant hormone therapy was used in 74 (33.6%) patients. RESULTS: Median follow-up was 53.5 months (24-116). Five year BFFS was 83.0% and 83.7% using, respectively, the ASTRO and Phoenix criteria. Low -and intermediate- risk patients presented, respectively, 86.7% and 77.8% 5-year BFFS using the ASTRO definition (p=0.069), and 88.5% and 78.6% considering the Phoenix criteria (p=0.016). Bounce was observed in 66 (30%) patients. Multivariate analysis detected PSA at diagnosis <10 ng/ml and less than 50% positive biopsy fragments as favourable prognostic factors, regarding BF using both criteria. For the Phoenix criteria, also Gleason score <7 and low-risk group were identified as independent favourable prognostic factors. CONCLUSIONS: LDRB alone should be considered mostly for low-risk patients. PSA level was a strong independent prognostic factor. We support the use of the Phoenix criteria for detection of BF in patients submitted to LDRB alone.