Paulo Henrique Pires de Aguiar

Hospital De Clínicas De Porto Alegre, Pôrto de São Francisco dos Casaes, Rio Grande do Sul, Brazil

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Publications (108)115.55 Total impact

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    ABSTRACT: This study was undertaken to determine variables that could predict, in the perioperative period of anterior communicating artery (ACom) aneurysms surgeries, the likelihood of postoperative sequelae and complications, after temporary arterial occlusion (TAO).
    Acta neurochirurgica. Supplement 01/2015; 120:231-5. DOI:10.1007/978-3-319-04981-6_39
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    ABSTRACT: The posterior cerebral artery (PCA) is divided into 4 segments: precommunicating segment (P1), postcommunicating segment (P2), quadrigeminal segment (P3), and calcarine segment (P4). Small aneurysms are more prevalent than large aneurysms in patients with ruptured aneurysms. P2 and P3 aneurysms are usually managed by the subtemporal approach. This is a case report of rupture saccular aneurysm of posterior cerebral artery on P2P segment. The authors show the surgical steps of these rare aneurysms with an illustrative case.
    Case Reports in Medicine 12/2014; 2014:325414. DOI:10.1155/2014/325414
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    ABSTRACT: Background Anterior petrosectomy has become an increasingly used approach for petroclival lesions. This study measures the volume and the anatomical variants of the anterior portion of the petrous apex outlined by the Kawase triangle using computed tomography (CT). Methods This was a transversal retrospective study. We assessed the anterior petrous apex portion outlined by the Kawase triangle in consecutive patients > 18 years of age from CT scans of temporal bone stored in an archive system. The volumetry was performed on a workstation. Results A total of 154 petrosal apex were analyzed in 77 patients (36 men). The average volume of the region outlined by the Kawase triangle was 1.89 ± 0.52 cm(3). The volume average in men was 2.01 ± 0.58 cm(3), and the average in women was 1.79 ± 0.41 cm(3). Intra- and interobserver agreement were both excellent, and there was little variance. Nineteen petrous apex demonstrated anatomical variations. In 18 cases it was pneumatized, and in one case a vascular or nerve-like structure was identified, a report we did not find in the literature. Conclusion The volumetry of the petrous apex anterior portion outlined by the Kawase triangle can be made by CT with excellent intra- and interobserver agreement and reproducibility. There are anatomical variants in this region that are relevant to surgery.
    06/2014; 75(3):147-51. DOI:10.1055/s-0033-1356491
  • Marcel R. Pierobon, Gustavo R. Isolan, Paulo H.P. de Aguiar
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    ABSTRACT: One-quarter of all cerebral aneurysms affect the posterior communicating artery. The clinical course typically involves subarachnoid hemorrhage and oculomotor nerve palsy. The objective of this study was to apply the de Aguiar and colleagues’ anatomicosurgical classification of posterior communicating artery aneurysms to a series of ruptured and incidental aneurysms treated at a single center and ascertain whether correlations exist between this classification and surgical outcomes (successful or failed occlusion). A single-center, retrospective cohort study based on imaging data was carried out between 2005 and 2010. Patients were allocated into 2 groups depending on aneurysm presentation (acutely ruptured or incidental). In this series, posterior communicating artery aneurysms were 4 to 5 times more common in women than in men, and type II (temporal) aneurysms were those most frequently found. The worst prognosis in the acute bleeding group was seen in cases with fetal variant circulation. The overall prognosis was poorer for temporal aneurysms, particularly those with a higher Hunt and Hess scale grade. Unruptured aneurysms were associated with better outcomes after surgical treatment.
    Neurosurgery Quarterly 01/2014; 24(2):114-120. DOI:10.1097/WNQ.0b013e31828cc3ba · 0.09 Impact Factor
  • 01/2014; 1(3). DOI:10.5935/MedicalExpress.2014.03.12
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    ABSTRACT: Intraoperative neurophysiology monitoring (IOM) is a valuable tool in cerebellopontine angle (CPA) surgeries posing risk to the cranial nerves. Transcranial electrical stimulation (TES) for cranial nerves has been performed in the last 7 years, for obtaining the facial nerve motor evoked potential (MEP), using either C3/C4-Cz or C3-C4 (or inverse) stimulating points, which have been correlated with facial nerve functional outcome. Intraoperative surgical and electrophysiological findings were documented prospectively. Patient files were reviewed for clinical data. We studied 23 patients undergoing CPA tumor resection using C5 or C6-Cz montage for TES, and were able to determine the correlation between facial nerve functional outcome and the amplitude drop of facial MEP above 50 %. Patients were evaluated for immediate facial nerve outcome and 6 months after the surgery. Follow-up was performed by structured telephone interviews with local physicians. The sensibility of the studied parameters was 92.8 % for amplitude drop of facial nerve MEP, with positive predictive value of 81.2 %. The absence of changes during IOM has shown a negative predictive value of 100 %. In this series, the used montage was effective in predicting new facial deficit.
    Acta Neurochirurgica 07/2013; 155(10). DOI:10.1007/s00701-013-1806-x · 1.79 Impact Factor
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    ABSTRACT: Meningiomas located in the petroclival junction are difficult lesions to manage. Usually, they are diagnosed when they become large-sized symptomatic lesions and extend to adjacent areas. The curative treatment is surgical resection, but the intricate and eloquent neurovascular anatomy of the petroclival complex and adjacent areas challenges the surgeon while considering total tumor resection against the acceptable morbidity and mortality. The authors report 10 case series of tumors arising from or extending to the petroclival junction; they included 10 meningiomas: 4 petroclival, 3 sphenopetroclival, 2 tentorial at the petroclival area, and 1 anterior petrosal operated from 2007 to 2011 in the Hiroshima University Hospital. They were subjected to the combined approaches: anterior petrosal, presigmoid, and retrosigmoid. The translabyrinth approach was added in 2 cases where hearing was previously lost. Gross total resection was possible in 6 cases. The mortality rate was 0. The main complications were postoperative cerebrospinal fluid leak in 1 case, permanent cranial nerve palsy in 3 cases, and venous congestion in 1 case. The main limiting factors for good outcome are the tumor size, wide attachment, hard consistency, bleeding, and preoperative clinical status. Involvement of the basilar artery and perforators, attachment to the brainstem, and avoidance of venous damage are also important points to be considered. As a rule, the anterior petrosal approach yields direct access to the tumor attachment, permitting early devascularization, and direct approach to medial cranial fossa base content. The retrosigmoid is necessary when the tumor is very large and has extended below the internal acoustic meatus. The presigmoid access is useful for cases where the tumors extend to the medial cranial fossa; it reduces the required amount of retraction of the temporal lobe, as it permits the surgeon to change the angle of attack from the lateral to the inferior range.
    Neurosurgery Quarterly 01/2013; 23(1):7-12. DOI:10.1097/WNQ.0b013e31825a6bdd · 0.09 Impact Factor
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    ABSTRACT: Background: Vasospasm is an important complication observed after subarachnoid hemorrhage (SAH) and is a frequent cause of mortality and morbidity. We present our routine management of vasospasm after SAH and emphasize the importance of transcranial Doppler (TCD) ultrasonography in this management. Method: Historical records and images were sampled from June 2005 to September 2011 for 110 patients with SAH due to ruptured aneurysm in the anterior circulation. All surviving patients were followed after discharge. Vasospasm was defined as mild (Lindegaard index 3-4), moderate (Lindegaard index 4-5), and severe (Lindegaard index greater than 5). We excluded patients treated after 72 h of symptom onset. TCD was performed twice per day. Findings: Ninety-nine patients had surgical clipping of the aneurysm, and 11 had endovascular treatment. Seventy patients treated by clipping and six treated by endovascular procedure had vasospasm. Of the 70 clipped patients with vasospasm, 40 had mild vasospasm, 13 had moderate vasospasm, and 17 had severe vasospasm. All six patients treated by coils had moderate vasospasm. The average duration of vasospasm was 9 days (from 7 to 32 days). Conclusions: TCD was crucial for monitoring patients with SAH, and to identify which patients will have a higher risk of developing vasospasm.
    Acta neurochirurgica. Supplement 01/2013; 115:75-6. DOI:10.1007/978-3-7091-1192-5_16
  • Paulo H Pires de Aguiar, Icaro Barros, Bernardo L Paiva, Renata F Simm
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    ABSTRACT: Background: Cerebral vasospasm after subarachnoid hemorrhage (SAH) is a major cause of morbidity and mortality. We studied the effects of clot removal on multiple outcome variables following the clipping of ruptured anterior communicating aneurysms. Methods: From 2007 to 2011, 30 patients with Fisher grade III aneurysmal SAH underwent clipping of an anterior communicating artery aneurysm before SAH day 3. There were 20 women and 10 men, mean age 53.4, range 28-80 years. Seventeen underwent fenestration of lamina terminalis and cisternal removal of clots (group A), and 13 did not (Group B). We compared clinical grades, presence of hydrocephalus at admission, treatment modality, occurrence of clinical vasospasm, the need for interventional vasospasm therapy, and need for ventriculoperitoneal shunting. Findings: Vasospasm affected 5 of 17 (29%) in group A and 8 of 13 (61.5%) in group B (p < 0.05). Endovascular treatment for vasospasm was required in one patient in group A (5.8% of 17, 20% of 5) and in five from group B (38.4% of 13, 62.5% of 8) (p < 0.05). Mortality was observed in one case in group A (5.8% of 17, 20% of 5) and in two cases in group B (15.3% of 13, 25% of 8) and was related to vasospasm after SAH. Ventriculoperitonal shunt (VPS) was required in one case in group A (5.8%) and in five cases in group B (38.4%). Conclusions: Fenestration of the lamina terminalis and removal of cisternal clots significantly decreased the incidence of post-SAH hydrocephalus and was associated with better outcomes in our series.
    Acta neurochirurgica. Supplement 01/2013; 115:91-3. DOI:10.1007/978-3-7091-1192-5_20
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    ABSTRACT: Una hernia de disco lumbar es una causa importante, así como la más frecuente causa del dolor lumbar y ciática. Muchos casos pueden ser fácilmente diagnosticados por el examen semiológico simple. La resonancia magnética (RM) proporciona un diagnóstico definitivo, incluso en atención ambulatoria. Varios tipos de quistes intraespinales con diferentes patogénesis se han descrito en el pasado como quistes perineurales, quistes sinoviales, los quistes aracnoideos y quistes ganglionares, enfermedades que son difíciles de diferenciar de la hernia de disco lumbar. Los autores observaron recientemente un caso de quiste intraespinal, que en comunicación con el disco intervertebral correspondiente, presentando signos y síntomas e incluso algunos hallazgos radiológicos que no se distinguen de los de la hernia discal lumbar. El diagnóstico fue determinado por RM y confirmado en la cirugía. En este artículo se describen las características de esta entidad clínica, incluyendo el aspecto clínico, radiológico e histológico, para discutir la posible patogénesis y tratamiento.
    Coluna/ Columna 12/2012; 11(4):329-332. DOI:10.1590/S1808-18512012000400017
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    ABSTRACT: OBJECTIVE: We used an assembly of electrodes C3 and C4-Cz in order to activate the motor cortical area of the corticobulbar tract to elucidate the motor-evoked potential of the contralateral mentalis muscle. METHOD: We compared this setup to that of an assembly with electrodes C5 or C6-Cz using a train of electrical pulses and a single electrical pulse. This analysis was made in 23 consecutive patients who underwent several varied surgeries and were prospectively operated on at Santa Paula Hospital between January and June 2011. RESULTS: The results showed that the assembly with C5 or C6-Cz produced a multisynaptic motor-evoked potential in the contralateral mentalis muscle in 86.9 % of the patients, whereas 82.6 % of patients stimulated at points C3 or C4-Cz presented the same response. However, both assemblies showed similar behavior with the use of a single electrical pulse for peripheral contralateral nerve stimulation. CONCLUSION: We concluded that the C5 or C6-Cz assembly was similar to C3 or C4-Cz in obtaining a multisynaptic response in the contralateral mentalis muscle, although it required less intensive stimulation than the C3 or C4- Cz assembly.
    Acta Neurochirurgica 10/2012; 154(12). DOI:10.1007/s00701-012-1505-z · 1.79 Impact Factor
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    ABSTRACT: The transsphenoidal approach is the preferred access used in surgical treatment of most sellar region pathologies. The use of endoscopy is advantageous, and it is considered a good alternative to the traditional microsurgical technique. The purpose of this study is to recognize and describe anatomical variations of the sphenoid sinus and the sellar region, mainly describing the anatomy of the posterior wall of the sphenoid sinus and analyzing intercarotid distances in 3 regions. Thirty sphenoid blocks treated with formaldehyde were injected and dissected. Using endoscopy, anatomical variations were studied and the intercarotid distances were measured at the tuberculum sellae, sellar floor and clivus. The types of sphenoid sinus found were: conchal in 1 (4.76 %), pré-sellar in 2 (9.52 %) and sellar in 19 (85.7 %) specimens. The mean distance found from the sphenoid sinus ostium to the sella turcica was 19 mm (±6.5) mm. The mean intercarotid distances found at the tuberculum sellae, sellar floor and clivus were respectively 13.32, 18.00 and 18.90 mm. Endoscopy, with its magnification and lighting provide a panoramic view of deep fields. The anatomical variations described in this study support the need for a careful evaluation of preoperative images in each case.
    Pituitary 07/2012; 16(2). DOI:10.1007/s11102-012-0413-9 · 2.22 Impact Factor
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    ABSTRACT: BACKGROUND AND PURPOSE:(1)H-MR spectroscopy is a useful tool in brain tumor evaluation. A critical point in obtaining representative spectra is the correct voxel positioning, which can be more accurate after Gd administration. Some experimental data suggested that Gd could cause Cho signal loss. Our aim was to evaluate the effect of Gd in the Cho peak area and width in patients with GBM.MATERIALS AND METHODS:We performed multivoxel (1)H-MR spectroscopy before and after Gd administration in 18 patients with GBM. Quantification of Cho peak area and width in each voxel was completed, and the Cho mean and maximum values before and after Gd injection were calculated in the tumor and contralateral hemisphere. Choline peak area and width values obtained before and after contrast were compared, considering as separate entities enhancing and nonenhancing tumoral voxels and the contralateral hemisphere.RESULTS:No statistically significant differences were found for the Cho peak area mean values in the tumoral voxels or contralaterally (P > .05). A tendency for an increase in the Cho peak width mean value was found in the tumoral enhancing voxels (P = .055). A statistically significant decrease was found for the mean value of the maximum Cho peak area in enhancing tumoral voxels (P = .020). No significant differences were found in the nonenhancing tumoral voxels or contralaterally (P > .05).CONCLUSIONS:The injection of Gd before performing (1)H-MR spectroscopy might not significantly affect the Cho peak area in patients with GBM. The paramagnetic contrast seems to cause a different effect, depending on Gd enhancement.
    American Journal of Neuroradiology 07/2012; 34(1). DOI:10.3174/ajnr.A3181 · 3.68 Impact Factor
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    ABSTRACT: CONTEXTO: O conhecimento das estruturas anatômicas da artéria carótida externa por meio do estudo estereoscópico pode determinar melhores resultados em microcirurgias da artéria carótida externa. OBJETIVO: Descrever as estruturas da artéria carótida externa sob a visão estereoscópica, identificando seus múltiplos aspectos. MÉTODOS: Doze regiões cervicais foram dissecadas, utilizando-se microscópico cirúrgico com 3 a 40x de aumento. As dissecções anatômicas foram documentadas utilizando-se a técnica para obtenção de imagens tridimensionais (3D), objetivando a produção de impressões estereoscópicas. RESULTADOS: O uso da técnica estereoscópica possibilitou a abordagem da circulação arterial extracraniana, sendo realizados estudos cirúrgicos do tipo combinado fossa posterior e fossa infratemporal, tornando as microcirurgias e os procedimentos neurocirúrgicos vasculares mais precisos. CONCLUSÃO: O uso das imagens obtidas pela técnica estereoscópica produziu um resultado mais assertivo em relação ao estudo da anatomia para a microcirurgia e procedimentos neurocirúrgicos, facilitando melhor aprendizado previamente à realização de procedimentos complexos em neurocirurgia.
    Jornal Vascular Brasileiro 03/2012; 11(1):03-11. DOI:10.1590/S1677-54492012000100002
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    ABSTRACT: The authors show their experience with brainstem cavernomas, comparing their data with the ones of a literature review. From 1998 to 2009, 13 patients harboring brainstem cavernomas underwent surgical resection. All plain films, medical records and images were reviewed in order to sample the most important data regarding epidemiology, clinical picture, radiological findings and surgical outcomes, as well as main complications. The mean age was 42.4 years (ranging from 19 to 70). No predominant gender: male-to-female ratio, 6:7. Pontine cases were more frequent. Magnetic resonance imaging was used as the imaging method to diagnose cavernomas in all cases. The mean follow-up was 71.3 months (range of 1 to 138 months). Clinical presentation was a single cranial nerve deficit, VIII paresis, tinnitus and hearing loss (69.2%). All 13 patients underwent resection of the symptomatic brainstem cavernoma. Complete removal was accomplished in 11 patients. Morbidity and mortality were 15.3 and 7.6%, respectively. Cavernomas can be resected safely with optimal surgical approach (feasible entry zone) and microsurgical techniques, and the goal is to remove all lesions with no cranial nerves impairment.
    01/2012; 10(1):67-73. DOI:10.1590/S1679-45082012000100014
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  • Jornal Vascular Brasileiro 01/2012; 11(2):114-122. DOI:10.1590/S1677-54492012000200008
  • Marcus André Acioly, Marina Liebsch, Paulo Henrique Pires de Aguiar, Marcos Tatagiba
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    ABSTRACT: BACKGROUND: Intraoperative neuromonitoring has been established as one of the methods by which modern neurosurgery can improve surgical results while reducing morbidity. Despite routine use of intraoperative facial nerve (FN) monitoring, FN injury still is a complication of major concern due to severe negative impact on patient's quality of life. METHODS: Through searches of PubMed, we provided a systematic review of the current literature up to February, 2011, emphasizing all respects of FN monitoring for cerebellopontine angle and skull base tumor surgery from description to current success on function prediction of standard and emerging monitoring techniques. RESULTS: Currently, standard monitoring techniques comprise direct electrical stimulation (DES), free-running electromyography (EMG), and facial motor evoked potential (FMEP). We included 62 studies on function prediction by investigating DES (43 studies), free-running EMG (13 studies), and FMEP (6 studies) criteria. DES mostly evaluated postoperative function by using absolute amplitude, stimulation threshold, and proximal-to-distal amplitude ratio, whereas free-running EMG used the train-time criterion. The prognostic significance of FMEP was assessed with the final-to-baseline amplitude ratio, as well as the event-to-baseline amplitude ratio and waveform complexity. CONCLUSIONS: Although there is a general agreement on the satisfactory functional prediction of different electrophysiological criteria, the lack of standardization in electrode montage and stimulation parameters precludes a definite conclusion regarding the best method. Moreover, studies emphasizing comparison between criteria or even multimodal monitoring and its impact on FN anatomical and functional preservation are still lacking in the literature.
    World Neurosurgery 11/2011; 80(6). DOI:10.1016/j.wneu.2011.09.026 · 2.42 Impact Factor
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    ABSTRACT: 1) To correlate the methylation status of the O6-methylguanine-DNA-methyltransferase (MGMT) promoter to its gene and protein expression levels in glioblastoma and 2) to determine the most reliable method for using MGMT to predict the response to adjuvant therapy in patients with glioblastoma. The MGMT gene is epigenetically silenced by promoter hypermethylation in gliomas, and this modification has emerged as a relevant predictor of therapeutic response. Fifty-one cases of glioblastoma were analyzed for MGMT promoter methylation by methylation-specific PCR and pyrosequencing, gene expression by real time polymerase chain reaction, and protein expression by immunohistochemistry. MGMT promoter methylation was found in 43.1% of glioblastoma by methylation-specific PCR and 38.8% by pyrosequencing. A low level of MGMT gene expression was correlated with positive MGMT promoter methylation (p = 0.001). However, no correlation was found between promoter methylation and MGMT protein expression (p = 0.297). The mean survival time of glioblastoma patients submitted to adjuvant therapy was significantly higher among patients with MGMT promoter methylation (log rank = 0.025 by methylation-specific PCR and 0.004 by pyrosequencing), and methylation was an independent predictive factor that was associated with improved prognosis by multivariate analysis. MGMT promoter methylation status was a more reliable predictor of susceptibility to adjuvant therapy and prognosis of glioblastoma than were MGMT protein or gene expression levels. Methylation-specific polymerase chain reaction and pyrosequencing methods were both sensitive methods for determining MGMT promoter methylation status using DNA extracted from frozen tissue.
    Clinics (São Paulo, Brazil) 09/2011; 66(10):1747-55. DOI:10.1590/S1807-59322011001000013 · 1.42 Impact Factor

Publication Stats

579 Citations
115.55 Total Impact Points

Institutions

  • 2014
    • Hospital De Clínicas De Porto Alegre
      Pôrto de São Francisco dos Casaes, Rio Grande do Sul, Brazil
  • 2009–2014
    • Hospital Santa Paula
      San Paulo, São Paulo, Brazil
  • 1998–2013
    • University of São Paulo
      • • Department of Neurology
      • • Faculty of Medicine (FM)
      San Paulo, São Paulo, Brazil
  • 2012
    • Hospital Israelita Albert Einstein
      San Paulo, São Paulo, Brazil
  • 2010–2012
    • Universidade Federal do Rio Grande do Sul
      Pôrto de São Francisco dos Casaes, Rio Grande do Sul, Brazil
  • 2011
    • Hospital Sirio Libanes
      Potengy, Rio Grande do Norte, Brazil
  • 2003–2010
    • Santa Casa Medicine School, São Paulo
      San Paulo, São Paulo, Brazil
    • São Paulo State University
      San Paulo, São Paulo, Brazil
    • Universidade Federal de São Paulo
      • Departamento de Neurologia e Neurocirurgia
      San Paulo, São Paulo, Brazil
  • 2008–2009
    • Hospital Samaritano São Paulo
      San Paulo, São Paulo, Brazil
  • 2006
    • Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo
      San Paulo, São Paulo, Brazil