Image-guided temporal bone dissection course

Introduction: Temporal bone anatomy is complex and demands a profound anatomical knowledge. Association between surgery and imaging helps in the process of learning three-dimensional (3D) anatomy and surgical techniques. High definition temporal bone imaging can play an important role in dissection training. Objective: To describe a computed tomography (CT) image-guided temporal bone dissection course for surgical training in otolaryngology and to verify the satisfaction level of the students with the course. Methods: Descriptive research. The course took place at a research laboratory, with three experienced temporal bone surgeons. The participants were 12 otolaryngology residents. The laboratory has 7 modern workstations with microscope and monitors linked with a computerized video system. Cadaveric temporal bones were donated to the university. Imaging acquisition of the cadaveric temporal bones used in the course was performed in a multislice CT scanner. The CT images of cadaveric temporal bones were available with real-time access on the laboratory monitor's screens during dissections. Results: A total of 13 temporal bones were included for dissection. Students had the opportunity to view on the same screen, simultaneously, both the dissection video and the respective CT images of their temporal bone anatomical specimens. This allowed correlating surgical and imaging aspects of temporal bone anatomy. At the end of the course, participants answered a satisfaction survey. Conclusion: Considering imaging methods are routinely used during most otologic surgeries, detailed knowledge of CT imaging should be explored in conjunction with the temporal bone anatomical dissection

Grau das malformações arteriovenosas cerebrais sem ruptura e o risco de acidente vascular cerebral e morte em pacientes não tratados

Introdução: As malformações arteriovenosas cerebrais (MAVs) são lesões complexas com potencial de causar hemorragia intracraniana (HIC). Estima-se que as taxas anuais de HIC em MAVs não tratadas situam-se entre 2% a 4%. A correlação entre as características de imagem presentes ao diagnóstico das MAVs, com o risco de apresentação hemorrágica inicial e com o risco de hemorragia subsequente é valiosa para prever a evolução destas lesões. Neste contexto, as MAVs não tratadas e não rotas são de especial interesse para pesquisa, e uma análise prospectiva com seguimento destas lesões poderá revelar fatores que predispõem à hemorragia. A relação entre os graus das MAVs (classificação de Spetzler-Martin) e o risco de hemorragia é muito debatida. Existe discordância sobre o papel dos parâmetros que determinam o grau da MAV (tamanho da lesão, tipo de drenagem venosa e localização cerebral) como fatores de risco para ocorrência de hemorragia. O ensaio clínico randomizado envolvendo MAVs cerebrais sem hemorragia - estudo ARUBA (A Randomized trial of Unruptured Brain Arteriovenous malformations), forneceu os primeiros resultados de um ensaio randomizado envolvendo MAVs não rotas. Os dados do ARUBA oferecem oportunidade para novos estudos sobre riscos de hemorragia em MAVs não rotas. Objetivo: Utilizar dados publicados no ARUBA para avaliar a relação entre os graus das MAVs não rotas e não tratadas e o risco de acidente vascular cerebral (AVC) subsequente e morte na história natural dessas lesões. Método: Estudo prospectivo que analisou coorte de pacientes (idade ≥ 18 anos) com MAVs não rotas que participaram do braço randomizado para receber tratamento conservador (observação, tratamento clínico), que integrou o ARUBA. Este estudo disponibilizou dados de sua análise “as treated” (como foram realmente tratados) para o grupo de tratamento conservador (MAVs não rotas e não tratadas). As MAVs foram estratificadas em graus (Spetzler- Martin). Para a análise de dados, a variável grau das MAVs foi dicotomizada em categorias: as MAVs dos graus I e II foram consideradas lesões de baixo grau; as MAVs dos graus III e IV foram consideradas de alto grau. Não houve registros de MAVs de grau V. O desfecho primário foi a ocorrência de AVC sintomático (hemorrágico ou isquêmico) ou morte por qualquer causa. A análise estatística foi realizada considerando as variáveis categóricas de alto ou baixo grau e correlacionando-as com a ocorrência do desfecho em cada categoria. Foi utilizado o teste exato de Fisher com valor de p < 0,05 e intervalos de confiança (IC) de 95%. Resultados: A amostra final do ARUBA foi de 223 pacientes randomizados. O grupo de tratamento conservador utilizado no estudo atual contou com 123 pacientes (“as treated”). Entre estes, 71 (57,7%) apresentaram lesões de baixo grau (I e II) e 52 (42,2%) de alto grau (III e IV). Do total de 10 (8,13%) desfechos primários, 3 (4,22%) ocorreram em MAVs de baixo grau e 7 (13,46%) em MAVs de alto grau. A correlação dos desfechos entre as categorias de graduação não demonstrou resultado significativo (p = 0,0942; RR = 0,319; IC 95%: 0,085 - 1,157). Conclusão: A análise da coorte de pacientes com MAVs não rotas e não tratadas do ARUBA demonstrou que as categorias de graduação (escala de Spetzler-Martin) não foram associadas ao desfecho de AVC subsequente ou morte. Este resultado levanta a questão de saber se é possível prever quais pacientes irão sangrar com base no grau da lesão, fornecendo um ponto de partida para mais investigações.Background: Brain arteriovenous malformations (AVMs) are complex lesions with potential to cause intracranial hemorrhage (ICH). Annual rates of ICH in untreated AVMs are estimated to range from 2% to 4%. The correlation between imaging characteristics present at the diagnosis of AVMs, with the risk of initial hemorrhagic presentation and with the subsequent (future) risk of hemorrhage, is valuable in predicting the evolution of these lesions. In this context, unruptured and untreated brain AVMs are of particular interest for research, and a prospective analysis of patients with this type of lesions may reveal which factors predispose to hemorrhage. The relationship between AVM grades (Spetzler-Martin classification) and the risk of hemorrhage is much debated. There is disagreement about the role of parameters that determine AVM grade (lesion size, venous drainage type and cerebral location) as risk factors for hemorrhage. The randomized clinical trial involving brain AVMs without hemorrhage - ARUBA study (A Randomized trial of Unruptured Brain Arteriovenous malformations), provided the first results of a randomized trial involving unruptured AVMs. ARUBA data offers opportunity for further studies on the risks of bleeding in unruptured AVMs. Aim: To use published data from ARUBA to assess the relationship between the grades of unruptured and untreated brain AVMs and the risk of subsequent stroke and death in the natural history of these lesions. Method: Prospective study that analyzed a cohort of patients (age ≥ 18 years) with unruptured AVMs, who participated in the arm randomized to receive conservative treatment (observation, medical management), which was part of ARUBA. This study provided data from its “as treated” analysis for the conservative treatment group (unruptured and untreated AVMs). The AVMs were stratified into grades (Spetzler-Martin). For data analysis, the AVM grade variable was dichotomized into categories: AVMs of grades I and II were considered low-grade lesions; AVMs of grades III and IV were considered high-grade. There were no records of Spetzler-Martin grade V AVMs. Primary outcome was the occurrence of symptomatic stroke (hemorrhagic or ischemic) or death from any cause. Statistical analysis was performed considering the categorical variables of high and low grade and correlating them with the occurrence of the outcome in each category. Fisher's exact test was used with a p value < 0.05 and 95% confidence intervals (CI). Results: The final ARUBA sample consisted of 223 randomized patients. The conservative treatment group used in the current study had 123 patients (“as treated”). Among these, 71 (57.7%) had lowgrade lesions (I and II) and 52 (42.2%) had high-grade lesions (III and IV). From the total of 10 (8.13%) primary outcomes, 3 (4.22%) occurred in low-grade AVMs and 7 (13.46%) in high-grade AVMs. The correlation of outcome occurrences between the grade categories did not show a significant result (p = 0.0942; RR = 0.319; 95% CI: 0.085 - 1.157). Conclusion: Analysis of the cohort of patients with unruptured and untreated AVMs from ARUBA showed that the graduation categories (Spetzler- Martin scale) were not associated with the outcome of subsequent stroke or death. This result raises the question whether it is possible to predict which patients will bleed based on lesion grade, providing a starting point for further investigations

Grau das malformações arteriovenosas cerebrais sem ruptura e o risco de acidente vascular cerebral e morte em pacientes não tratados

Introdução: As malformações arteriovenosas cerebrais (MAVs) são lesões complexas com potencial de causar hemorragia intracraniana (HIC). Estima-se que as taxas anuais de HIC em MAVs não tratadas situam-se entre 2% a 4%. A correlação entre as características de imagem presentes ao diagnóstico das MAVs, com o risco de apresentação hemorrágica inicial e com o risco de hemorragia subsequente é valiosa para prever a evolução destas lesões. Neste contexto, as MAVs não tratadas e não rotas são de especial interesse para pesquisa, e uma análise prospectiva com seguimento destas lesões poderá revelar fatores que predispõem à hemorragia. A relação entre os graus das MAVs (classificação de Spetzler-Martin) e o risco de hemorragia é muito debatida. Existe discordância sobre o papel dos parâmetros que determinam o grau da MAV (tamanho da lesão, tipo de drenagem venosa e localização cerebral) como fatores de risco para ocorrência de hemorragia. O ensaio clínico randomizado envolvendo MAVs cerebrais sem hemorragia - estudo ARUBA (A Randomized trial of Unruptured Brain Arteriovenous malformations), forneceu os primeiros resultados de um ensaio randomizado envolvendo MAVs não rotas. Os dados do ARUBA oferecem oportunidade para novos estudos sobre riscos de hemorragia em MAVs não rotas. Objetivo: Utilizar dados publicados no ARUBA para avaliar a relação entre os graus das MAVs não rotas e não tratadas e o risco de acidente vascular cerebral (AVC) subsequente e morte na história natural dessas lesões. Método: Estudo prospectivo que analisou coorte de pacientes (idade ≥ 18 anos) com MAVs não rotas que participaram do braço randomizado para receber tratamento conservador (observação, tratamento clínico), que integrou o ARUBA. Este estudo disponibilizou dados de sua análise “as treated” (como foram realmente tratados) para o grupo de tratamento conservador (MAVs não rotas e não tratadas). As MAVs foram estratificadas em graus (Spetzler- Martin). Para a análise de dados, a variável grau das MAVs foi dicotomizada em categorias: as MAVs dos graus I e II foram consideradas lesões de baixo grau; as MAVs dos graus III e IV foram consideradas de alto grau. Não houve registros de MAVs de grau V. O desfecho primário foi a ocorrência de AVC sintomático (hemorrágico ou isquêmico) ou morte por qualquer causa. A análise estatística foi realizada considerando as variáveis categóricas de alto ou baixo grau e correlacionando-as com a ocorrência do desfecho em cada categoria. Foi utilizado o teste exato de Fisher com valor de p < 0,05 e intervalos de confiança (IC) de 95%. Resultados: A amostra final do ARUBA foi de 223 pacientes randomizados. O grupo de tratamento conservador utilizado no estudo atual contou com 123 pacientes (“as treated”). Entre estes, 71 (57,7%) apresentaram lesões de baixo grau (I e II) e 52 (42,2%) de alto grau (III e IV). Do total de 10 (8,13%) desfechos primários, 3 (4,22%) ocorreram em MAVs de baixo grau e 7 (13,46%) em MAVs de alto grau. A correlação dos desfechos entre as categorias de graduação não demonstrou resultado significativo (p = 0,0942; RR = 0,319; IC 95%: 0,085 - 1,157). Conclusão: A análise da coorte de pacientes com MAVs não rotas e não tratadas do ARUBA demonstrou que as categorias de graduação (escala de Spetzler-Martin) não foram associadas ao desfecho de AVC subsequente ou morte. Este resultado levanta a questão de saber se é possível prever quais pacientes irão sangrar com base no grau da lesão, fornecendo um ponto de partida para mais investigações.Background: Brain arteriovenous malformations (AVMs) are complex lesions with potential to cause intracranial hemorrhage (ICH). Annual rates of ICH in untreated AVMs are estimated to range from 2% to 4%. The correlation between imaging characteristics present at the diagnosis of AVMs, with the risk of initial hemorrhagic presentation and with the subsequent (future) risk of hemorrhage, is valuable in predicting the evolution of these lesions. In this context, unruptured and untreated brain AVMs are of particular interest for research, and a prospective analysis of patients with this type of lesions may reveal which factors predispose to hemorrhage. The relationship between AVM grades (Spetzler-Martin classification) and the risk of hemorrhage is much debated. There is disagreement about the role of parameters that determine AVM grade (lesion size, venous drainage type and cerebral location) as risk factors for hemorrhage. The randomized clinical trial involving brain AVMs without hemorrhage - ARUBA study (A Randomized trial of Unruptured Brain Arteriovenous malformations), provided the first results of a randomized trial involving unruptured AVMs. ARUBA data offers opportunity for further studies on the risks of bleeding in unruptured AVMs. Aim: To use published data from ARUBA to assess the relationship between the grades of unruptured and untreated brain AVMs and the risk of subsequent stroke and death in the natural history of these lesions. Method: Prospective study that analyzed a cohort of patients (age ≥ 18 years) with unruptured AVMs, who participated in the arm randomized to receive conservative treatment (observation, medical management), which was part of ARUBA. This study provided data from its “as treated” analysis for the conservative treatment group (unruptured and untreated AVMs). The AVMs were stratified into grades (Spetzler-Martin). For data analysis, the AVM grade variable was dichotomized into categories: AVMs of grades I and II were considered low-grade lesions; AVMs of grades III and IV were considered high-grade. There were no records of Spetzler-Martin grade V AVMs. Primary outcome was the occurrence of symptomatic stroke (hemorrhagic or ischemic) or death from any cause. Statistical analysis was performed considering the categorical variables of high and low grade and correlating them with the occurrence of the outcome in each category. Fisher's exact test was used with a p value < 0.05 and 95% confidence intervals (CI). Results: The final ARUBA sample consisted of 223 randomized patients. The conservative treatment group used in the current study had 123 patients (“as treated”). Among these, 71 (57.7%) had lowgrade lesions (I and II) and 52 (42.2%) had high-grade lesions (III and IV). From the total of 10 (8.13%) primary outcomes, 3 (4.22%) occurred in low-grade AVMs and 7 (13.46%) in high-grade AVMs. The correlation of outcome occurrences between the grade categories did not show a significant result (p = 0.0942; RR = 0.319; 95% CI: 0.085 - 1.157). Conclusion: Analysis of the cohort of patients with unruptured and untreated AVMs from ARUBA showed that the graduation categories (Spetzler- Martin scale) were not associated with the outcome of subsequent stroke or death. This result raises the question whether it is possible to predict which patients will bleed based on lesion grade, providing a starting point for further investigations

Image-guided Temporal Bone Dissection Course

Introduction Temporal bone anatomy is complex and demands a profound anatomical knowledge. Association between surgery and imaging helps in the process of learning three-dimensional (3D) anatomy and surgical techniques. High definition temporal bone imaging can play an important role in dissection training. Objective To describe a computed tomography (CT) image-guided temporal bone dissection course for surgical training in otolaryngology and to verify the satisfaction level of the students with the course. Methods Descriptive research. The course took place at a research laboratory, with three experienced temporal bone surgeons. The participants were 12 otolaryngology residents. The laboratory has 7 modern workstations with microscope and monitors linked with a computerized video system. Cadaveric temporal bones were donated to the university. Imaging acquisition of the cadaveric temporal bones used in the course was performed in a multislice CT scanner. The CT images of cadaveric temporal bones were available with real-time access on the laboratory monitor's screens during dissections. Results A total of 13 temporal bones were included for dissection. Students had the opportunity to view on the same screen, simultaneously, both the dissection video and the respective CT images of their temporal bone anatomical specimens. This allowed correlating surgical and imaging aspects of temporal bone anatomy. At the end of the course, participants answered a satisfaction survey. Conclusion Considering imaging methods are routinely used during most otologic surgeries, detailed knowledge of CT imaging should be explored in conjunction with the temporal bone anatomical dissection