Rui Vaz
University of Porto
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Featured researches published by Rui Vaz.
Neurosurgery | 1995
Josue Pereira; Rui Vaz; Davide Carvalho; Celso Cruz
We describe the case of a patient with an exclusively intrasellar mass, disclosed because of a left sixth nerve palsy and headaches. No other manifestation of disease, namely, endocrinological, was present. The lesion was approached transsphenoidally, and the pathological examination revealed a tuberculoma. Complete removal was achieved, and the patient started postoperative antituberculous therapy. In some circumstances, thickening of the infundibulum and the pituitary stalk could preoperatively suggest the diagnosis of hypophysial tuberculoma.
Neurosurgery | 1995
Josue Pereira; Rui Vaz; Davide Carvalho; Celso Cruz
: We describe the case of a patient with an exclusively intrasellar mass, disclosed because of a left sixth nerve palsy and headaches. No other manifestation of disease, namely, endocrinological, was present. The lesion was approached transsphenoidally, and the pathological examination revealed a tuberculoma. Complete removal was achieved, and the patient started postoperative antituberculous therapy. In some circumstances, thickening of the infundibulum and the pituitary stalk could preoperatively suggest the diagnosis of hypophysial tuberculoma.
Neurosurgery | 1990
Antnio Cerejo; Rui Vaz; Pedro Barata Feyo; Celso Cruz
A case of subarachnoid hemorrhage caused by a cervical hemangioblastoma is presented. The clinical picture was indistinguishable from that of a subarachnoid hemorrhage from an intracranial lesion. The diagnosis was established by angiography and water-soluble contrast myelography followed by cervical computed tomographic scan. At surgery, the tumor was completely removed, and no neurological deficit was observed after the operation.
Neurosurgery | 2002
Paulo Pereira; António Cerejo; Joaquim Cruz; Rui Vaz
OBJECTIVE AND IMPORTANCE This case report illustrates the possible occurrence of intracranial aneurysms after surgery and radiation-induced vasculopathy. CLINICAL PRESENTATION An internal carotid bifurcation aneurysm was diagnosed in a 19-year-old woman in a routine follow-up examination by magnetic resonance imaging 5 years after subtotal removal of a giant cystic craniopharyngioma treated by postoperative external radiotherapy. The presence of the aneurysm was confirmed by angiography. INTERVENTION It was decided to treat the aneurysm by embolization with Guglielmi detachable coiling. However, at the beginning of the procedure, a few weeks after the diagnosis, a dramatic reduction in the carotid artery blood flow was observed, along with signs of thrombosis inside the aneurysm. In light of these findings, the procedure was aborted. Four months later, another angiographic examination confirmed the exclusion of the aneurysm and compensatory flow through the external carotid artery. CONCLUSION During the assessment of patients who have undergone postoperative radiotherapy, the potential for the development of aneurysms and radiation-induced vasculopathy exists and should be kept in mind. Considering the potential for spontaneous thrombosis of these aneurysms, cautious judgment is recommended before making a decision to treat them.
Acta Neurochirurgica | 2001
P. Pereira; F. Duarte; R. Lamas; Rui Vaz
Summary We report one case of spontaneous thoracic spinal cord herniation presenting with a progressive spastic paraparesis for 4 years in a 55 years old man. From preoperative MRI, showing a ventrally displaced atrophic spinal cord at T2–T3 level, a dorsal intradural arachnoid cyst was suspected. At operation, after a 3 level laminectomy, no arachnoid cyst was found and spinal cord herniation into a meningeal diverticulum was confirmed. The herniated myelon was replaced intradurally and the lumen of the diverticulum was filled with Teflon® settled with fibrin glue to prevent recurrence. Postoperatively some neurological recovery was achieved. The literature was reviewed, regarding clinical and epidemiological features, proposed pathophysiological mechanisms, treatment options and outcome. Only 32 surgically proved cases of thoracic spinal cord herniation with no past history of spine trauma, injury or surgery were found.
Journal of Neuro-oncology | 1998
Rui Vaz; Nuno Borges; Celso Cruz; Isabel Azevedo
We undertook a morphological study of small pieces of peritumoral brain tissue removed from seven patients with meningiomas submitted to surgery. All patients had cerebral edema, as shown by preoperative C.T. and N.M.R.. Control specimens were obtained from five patients undergoing ventriculo-peritoneal shunt. The tissue fragments were fixed in glutaraldehyde-osmium and embedded in Epon. In semi-thin sections observed under light microscopy peritumoral endothelial cells exhibited voluminous cytoplasm and nucleus. Morphometrical evaluation confirmed that these endothelial cell nuclei were significantly larger than controls. Under the electron microscope those cells showed nuclei rich in euchromatin and cytoplasm rich in pinocytotic vesicles. The morphological changes observed suggest a process of dedifferentiation of brain peritumoral capillary cells and are compatible with an increase in permeability. Both events, which may be due to diffusion of a tumoral vascular permeability factor, favour the hypothesis that peritumoral brain tissue contributes to edema fluid that accumulates around meningiomas.
Journal of Oncology | 2013
Paulo Linhares; Bruno Carvalho; Rita Figueiredo; Rui M. Reis; Rui Vaz
Introduction. The aim of this study was to determine the frequency of pseudoprogression in a cohort of glioblastoma (GBM) patients following radiotherapy/temozolomide (RT/TMZ) by comparing Macdonald criterial to Response Assessment in Neuro-Oncology (RANO) criteria. The impact on prognosis and survival analysis was also studied. Materials and Methods. All patients receiving RT/TMZ for newly diagnosed GBM from January 2005 to December 2009 were retrospectively evaluated, and demographic, clinical, radiographic, treatment, and survival data were reviewed. Updated RANO criteria were used for the evaluation of the pre-RT and post-RT MRI and compared to classic Macdonald criteria. Survival data was evaluated using the Kaplan-Meier and log-rank analysis. Results and Discussion. 70 patients were available for full radiological response assessment. Early progression was confirmed in 42 patients (60%) according to Macdonald criteria and 15 patients (21%) according to RANO criteria. Pseudoprogression was identified in 10 (23.8%) or 2 (13.3%) patients in Macdonald and RANO groups, respectively. Cumulative survival of pseudoprogression group was higher than that of true progression group and not statistically different from the non-progressive disease group. Conclusion. In this cohort, the frequency of pseudoprogression varied between 13% and 24%, being overdiagnosed by older Macdonald criteria, which emphasizes the importance of RANO criteria and new radiological biomarkers for correct response evaluation.
Cancer Epidemiology, Biomarkers & Prevention | 2011
Bruno M. Costa; Marta Viana-Pereira; R Fernandes; Sandra Costa; Paulo Linhares; Rui Vaz; Céline Pinheiro; Jorge Lima; Paula Soares; Augusta Mendes da Silva; Fernando Pardal; Júlia Amorim; Rui Nabiço; Rui M. S. Almeida; Carlos Alegria; Manuel Pires; Ernesto de Carvalho; Pedro Oliveira; José Manuel Lopes; Rui M. Reis
Background: The epidermal growth factor receptor (EGFR) regulates important cellular processes and is frequently implicated in human tumors. Three EGFR polymorphisms have been described as having a transcriptional regulatory function: two single-nucleotide polymorphisms in the essential promoter region, −216G/T and −191C/A, and a polymorphic (CA)n microsatellite sequence in intron 1. We aimed to elucidate the roles of these EGFR polymorphisms in glioma susceptibility and prognosis. Methods: We conducted a case–control study with 196 patients with glioma and 168 cancer-free controls. Unconditional multivariate logistic regression models were used to calculate ORs and 95% confidence intervals. A Cox regression model was used to evaluate associations with patient survival. False-positive report probabilities were also assessed. Results: None of the EGFR −216G/T variants was significantly associated with glioma risk. The −191C/A genotype was associated with higher risk for glioma when the (CA)n alleles were classified as short for ≤16 or ≤17 repeats. Independently of the (CA)n repeat cutoff point used, shorter (CA)n repeat variants were significantly associated with increased risk for glioma, particularly glioblastoma and oligodendroglioma. In all tested models with different (CA)n cutoff points, only −191C/A genotype was consistently associated with improved survival of patients with glioblastoma. Conclusions: Our findings implicate EGFR −191C/A and the (CA)n repeat polymorphisms as risk factors for gliomas, and suggest −191C/A as a prognostic marker in glioblastoma. Impact: Our data support a role of these EGFR polymorphisms in determining glioma susceptibility, with potential relevance for molecularly based stratification of patients with glioblastoma for individualized therapies. Cancer Epidemiol Biomarkers Prev; 20(12); 2610–7. ©2011 AACR.
British Journal of Plastic Surgery | 1993
Horácio Costa; António Cerejo; António Baptista; Rui Vaz; Maia Gonçalves; António Guimara˜es; José Amarante; Celso Cruz; Flávio Guimara˜es
We report the clinical use of galea frontalis myofascial flaps in the treatment of anterior fossa cerebrospinal fluid leaks after trauma. This flap provides an adequately sized and vascularised barrier between the cranial and nasal cavities through which the cells of the inflammatory response reach the target area. This technique was used in 9 cases with complete success; in 5 out of 9 patients, repair of an anterior cranial base bone defect was also performed with split calvarial bone grafts, harvested from the frontal craniotomy bone. In all patients, neither recurrence of the CSF leakage nor postoperative meningitis or its recurrence were observed.
Acta Neurochirurgica | 1998
Rui Vaz; António Sarmento; Nuno Borges; Celso Cruz; Telma Azevedo
Summary Several experimental brain oedema models are currently available, but most of them are very different from what happens in clinical practice. As it is simple and seems to replicate the range of injuries seen in man we decided to evaluate Marmarous model of head injury in order to test physiopathogenic and therapeutic hypotheses.Three groups of Wistar rats weighing 360–400 gr, anaesthetized with sodium pentobarbitone and breathing spontaneously, without tracheal intubation, were studied. In the first group six animals were killed two hours after injury and the brains water content compared with that of nine controls. In another group Evans blue (100 mg/kg) was injected one hour before trauma and dyes extraction ratio determined at various times after injury: five animals at 15 minutes, six at 30 minutes, five at 60 minutes and nine at 120 minutes. A total of twenty-eight animals served as controls. In the last group morphological studies with light and electron microscopy were performed in the traumatized brain tissue from rats killed 5 and 120 minutes after injury and in brain tissue from control rats.Results showed that Marmarous brain trauma model induced perivascular brain oedema, already visible at the ultrastructural level 5 minutes after the injury. Endothelial cells themselves were “oedematiated”, rich in pinocytotic vesicles and membrane blebs, and presented intact tight junctions. Two hours after trauma the perivascular oedema was more marked. At this time the brain water content was significantly higher than that in controls. Evans blue extraction ratio increased linearly with time, being significantly higher than in controls 120 minutes after injury.We conclude that Marmarous model is a suitable model for the study of brain oedema induced by trauma, and that this oedema, assessed by three different methodologies, was statistically significant two hours after injury.