Computer vision coaching microsurgical laboratory training: PRIME (Proficiency Index in Microsurgical Education) proof of concept.

Computer vision (CV) feedback could be aimed as a constant tutor to guide ones proficiency during microsurgical practice in controlled environments. Five neurosurgeons with different levels of microsurgical expertise performed simulated vessel dissection and micro-suture in an ex vivo model for posterior computer analysis of recorded videos. A computer program called PRIME (Proficiency Index of Microsurgical Education) used in this research recognized color-labeled surgical instruments, from downloading videos into a platform, with a range of motion greater than 3 mm, for objective evaluation of number of right and left hand movements. A proficiency index of 0 to 1 was pre-established in order to evaluate continuous training improvement. PRIME computer program captured all hand movements executed by participants, except for small tremors or inconsistencies that have a range of motion inferior to 3 mm. Number of left and right hand movements were graphically expressed in order to guide more objective and efficacious training for each trainee, without requiring body sensors and cameras around the operating table. Participants with previous microsurgical experience showed improvement from 0.2 to 0.6 (p < 0.05), while novices had no improvement. Proficiency index set by CV was suggested, in a self-challenge and self-coaching manner. PRIME would offer the capability of constant laboratory microsurgical practice feedback under CV guidance, opening a new window for oriented training without a tutor or specific apparatus regarding all levels of microsurgical proficiency. Prospective, large data study is needed to confirm this hypothesis.

Impact on quality of life in obstructive sialadenitis predicting outcomes after sialendoscopy.

PURPOSE: Sialendoscopy is a minimally invasive procedure considered a paradigm shift in the treatment of obstructive sialadenitis. However, it shows an average need for revision procedure in up to 24% of operated cases. This study analyzed whether patient-related variables could predict the need for a revision during postoperative follow-up. METHODS: From 2012 to 2020, this prospective comparative study analyzed demographic data as well as preoperative responses to the "Manukau Salivary Symptoms Score" (MSSS) questionnaire as predictors of the need for a revision procedure due to symptoms recurrence. RESULTS: 188 sialendoscopies (39.4% for stones/60.6% for stenoses) in 112 parotid (59.6%) and 76 submandibular glands (40.4%) were included in this study. Forty patients (21.3%) required a revision procedure. The variable "Impact on quality of life" in the preoperative period of patients with sialoliths showed that the likelihood of a revision procedure increases by 33.6% with each increase in the 10-point Likert scale presented in the MSSS (p = 0.010, OR = 1336, CI = 1.071 to 1.667). This finding was not influenced by the location of the sialolith in the duct (p = 0.415), size (p = 0.058) or number of stones (P = 0.476). Other demographic variables related to the patient showed no association with the need of a revision procedure. CONCLUSION: Further studies should be performed to exclude the influence of other variables on the results; however, special attention should be given to patients who report a greater pre-operative impact on quality of life due to sialolithiasis. LEVEL OF EVIDENCE: II.

Development and validation a task-specific checklist for a microsurgical varicocelectomy simulation model.

PURPOSE: To develop and validate a new test of specific technical skills required for microsurgical varicocelectomy. MATERIALS AND METHODS: An electronic questionnaire was sent to 558 members of the Brazilian Society of Urology for the validation of the task-specific checklist (TSC) for assessment of microsurgical varicocelectomy. Participants who had experience in this procedure were selected as judges. For construct validation, 12 participants including attending urologists and urological residents in training were recruited for voluntary participation. We formed a group of three experts and a group of nine novices, who had to perform the steps of microsurgical varicocelectomy on a simulation model using human placenta. Each participant was filmed and two blinded raters would then evaluate their performance using the TSC of microsurgical varicocelectomy. RESULTS: 14 judges were recruited. The assessment tool was reformulated, according to the judges suggestions and had the content validity achieved. The final version of the TSC was comprised of the task-specific score, a series of 4 items scored in a binary fashion designed for microscopic sub-inguinal varicocelectomy. The differences between the performance of participants with different levels of experience reflected the construct validity. The reliability between the raters was high. The mean time required to complete the training of microsurgical varicocelectomy in simulation model was significantly shorter for experts compared to novices (201 vs. 496 seconds, p=0.01). CONCLUSIONS: This preliminary study suggests that the task-specific checklist of microsurgical varicocelectomy is reliable and valid in assessing microsurgical skills.

Choroid plexus cauterization on treatment of hydranencephaly and maximal hydrocephalus.

INTRODUCTION: The standard treatment for hydranencephaly and maximal hydrocephalus consists of inserting shunts, although complications frequently occur. Choroid plexus cauterization (CPC) is an alternative, but its long-term efficacy and the factors associated with the success and failure of controlling head circumference (HC) are not well defined. OBJECTIVE: This study aims to evaluate the long-term efficacy and factors related to the success rate of CPC in the treatment of hydranencephaly and maximal hydrocephalus. METHOD: Forty-two children with maximal hydrocephalus and hydranencephaly underwent CPC from 2006 to 2014 and were retrospectively evaluated. Children with less than 3 months of follow-up were excluded. The long-term efficacy and success rate of possible variables (i.e., sex, type of malformation, type of surgery performed, treatment hospital, age, and HC at the time of surgery and birth) were evaluated. RESULTS: Thirty-four children were considered for the effectiveness analysis. Treatment was successful in 24 children (70.6%), and failure occurred in 10 children (29.4%). Failure was detected soon after the endoscopic procedure (average 116 days). There was no difference in effectiveness when comparing the age at the moment of surgery (p = 0.473), type of malformation (p = 1), HC at birth (0.699), and HC at the time of surgery (p = 0.648). The surgical death rate was 7.14%. CONCLUSION: Endoscopic CPC was a valid procedure used to treat hydranencephaly and maximal hydrocephaly, and it was effective in 70.6% of cases, with an average follow-up period of 32 months. When failures occurred, they occurred early. None of the analyzed variables interfered with the success of the treatment.

Neurosurgical Microvascular Anastomosis: Systematic Review of the Existing Simulators and Proposal of a New Training Classification System.

BACKGROUND: The literature lacks a combined analysis of neurosurgical microvascular anastomosis training models. We performed a systematic literature search to provide an overview of the existing models and proposed a classification system based on the level of simulation and reproducibility of the microvascular anastomosis. METHODS: The systematic literature search followed the PRISMA guidelines. We consulted MEDLINE, Web of Knowledge, and EMBASE independently for papers about bypass training models. Every training model was analyzed according to six tasks supposed to esteem their fidelity to the real operative setting by using a scoring system from zero to two. Finally, authors classified the models into five classes, from A to E, by summing the individual scores. RESULTS: This study included 109 papers for analysis. Training models were grouped into synthetic tubes, ex vivo models (animal vessels, fresh human cadavers, human placentas) and in vivo simulators (live animals-rats, rabbits, pigs). By applying the proposed classification system, live animals and placentas obtained the highest scores, falling into class A (excellent simulators). Human cadavers and animal vessels (ex vivo) were categorized in class B (good simulators), followed by synthetic tubes (class C, reasonable simulators). CONCLUSIONS: The proposed classification system helps the neurosurgeon to analyze the available training models for microvascular anastomosis critically, and to choose the most appropriate one according to the skills they need to improve.

Stroke Microsurgical Thrombectomy Human Placenta Simulator.

BACKGROUND: Stroke microsurgical cerebrovascular thrombectomy reports are limited, although this technique could be used in many centers as a primary treatment or a salvage intervention option. It requires great ability, so our aim is to describe and validate a stroke microsurgical thrombectomy ex vivo simulator with operative nuances analysis. METHODS: Human placenta (HP) models simulated middle cerebral artery vessels with intraluminal thrombus to be microsurgically excised. Six neurosurgeons performed 1-mm and 2-mm longitudinal and transverse arteriotomy in different arteries to remove a 1.5-cm length thrombus. Validation through construct validity compared time to complete the task, complete vessel cleaning, vessel manipulation, vessel stenosis, and leakage in both techniques. RESULTS: All 6 HP models reproduced with fidelity stroke microsurgical thrombectomy, so participants completed 24 sessions, 4 for each neurosurgeon on the same model in different arteries. Construct validity highlighted microsurgical technical difficulties with positive results obtained by parameters variation during performance. Transverse arteriotomy with 1-mm length had best results (P < 0.05) allowing complete thrombus removal, less stenosis, and minor leakage in abbreviated time. CONCLUSIONS: A HP simulator can reproduce with high fidelity all stroke microsurgical thrombectomy part tasks. Transverse 1-mm arteriotomy followed by thrombectomy and 2 simple sutures can fulfill all quality assurance aspects in such intervention accordingly to training model, due to easier vessel opening, complete thrombus removal, no stenosis, and faster microsuture.

Validation of the Objective Structured Assessment of Technical Skill in Brasil.

BACKGROUND: The aim of this study was to perform a cross-cultural adaptation of the Objective Structured Assessment of Technical Skill (OSATS) tool into Brazilian Portuguese and to determine its reproducibility and validity in Brasil. METHODS: A Brazilian Portuguese version of OSATS was created through a process of translation, back-translation, expert panel evaluation, pilot testing, and then its validation. For the construct and the concurrent validities, twelve participants were divided into a group of six experts and six novices, who had to perform tasks on a simulation model using human placentas. Each participant was filmed, and two blinded raters would then evaluate their performance using the traditional subjective method and then the Brazilian Portuguese version of OSATS. RESULTS: The Brazilian Portuguese version of OSATS had the face, content, construct, and concurrent validities achieved. The average experts' score and standard deviations were 34 and 0.894, respectively, for Judge 1 and 34.33 and 0.816 for Judge 2. In the case of novices, it was 13.33 and 2.388 for Judge 1 and 13.33 and 3.204 for Judge 2. The concordance between the judges was evident, with the Correlation Coefficient (Pearson) of 0.9944 with CI 95% between 0.9797 and 0.9985, with p < 10-10, evidencing the excellent reproducibility of the instrument. CONCLUSION: This preliminary study suggests that the Brazilian Portuguese version of OSATS can reliably and validly assess surgical skills in Brasil.

Superficial Temporal Artery-Middle Cerebral Artery Bypass Ex Vivo Hybrid Simulator: Face, Content, Construct, and Concurrent Validity.

BACKGROUND: Cerebrovascular bypass surgical procedures require highly developed dexterity and refined bimanual technical skills. To attain such a level of prowess, neurosurgeons and residents have traditionally relied on "flat" models (without depth of field), such as chicken wings, live rats, silicone vessels, and other materials that stray far from the reality of the operating room, albeit more accessible. We have explored the use of a hybrid ex vivo simulator that takes advantage of the availability of placenta vessels and retains the complexity of surgery performed on a human skull to create a more realistic method for the development of cerebrovascular bypass surgical skills. METHODS: Twelve ex vivo simulators were constructed using 3 human placentas and 1 synthetic human skull for each. Face, content, construct, and concurrent validity were assessed by 12 neurosurgeons (6 trained vascular surgeons and 6 general neurosurgeons) and compared with those of other bypass models. RESULTS: The fidelity grade was ranked as low (Linkert scale score, 1-2), medium (score, 3), and high (score, 4-5). The face and content validity of the model showed high fidelity to superficial temporal artery-middle cerebral artery bypass surgery. Construct validity showed that cerebrovascular neurosurgeons had better performance, and concurrent validity highlighted that all surgical steps were present. CONCLUSION: The simulator was found to have strong face and content, construct, and concurrent validity for microsurgical cerebrovascular training, allowing for simulation of all surgical steps of the bypass procedure. The hybrid simulator seems to be a promising method for shortening the bypass surgery learning curve. However, more studies are required to evaluate the predictive validity of the model.

Quality Assurance During Brain Aneurysm Microsurgery-Operative Error Teaching.

INTRODUCTION: Quality assurance (QA) is a way to prevent mistakes in advance. Although it has been previously reported for surgical setup, there is no effective approach for minimizing microsurgical technical errors before an operation is done. Neurosurgery resident operative errors during brain aneurysm surgery could be foreseen by practicing in an ex vivo hybrid simulator with microscopic fluorescein vessel flow image. METHODS: Five vascular neurosurgeons and 8 junior/senior neurosurgical residents voluntarily joined this research initiative. The following methodology was adopted: 1) Identification of the 7 most-common resident operative performance errors during brain aneurysm surgery; 2) Design of exercises to prevent common mistakes in brain aneurysm microsurgery using a placenta simulator; and 3) Blinded staff neurosurgeon evaluation of resident performance during real brain aneurysm microsurgery. RESULTS: All key steps to perform such intervention were accomplished with a simulator that uses 2 placentas, a synthetic cranium, and microscopic fluorescein vessel flow image. Neurosurgery residents trained in this model had better surgical performance with fewer perioperative mistakes (P < 0.05). Fine microsurgical dissection of the arachnoid membrane and aneurysm sac were the most commonly improved tasks among the 7 common operative mistakes. Brain parenchyma traction with secondary bleeding was the only error not prevented after previous simulator training. CONCLUSIONS: There was a left-shift on the quality assurance line with residents who practiced brain aneurysm microsurgical errors in an ex vivo model. A multicentric prospective study is necessary to confirm the hypothesis that real operative error could be reduced after training in a realistic simulator.

Development and validation of the Skills Assessment in Microsurgery for Brain Aneurysms (SAMBA) instrument for predicting proficiency in aneurysm surgery.

OBJECTIVE: Surgical performance evaluation was first described with the OSATS (Objective Structured Assessment of Technical Skills) and modified for aneurysm microsurgery simulation with the OSAACS (Objective Structured Assessment of Aneurysm Clipping Skills). These methods rely on the subjective opinions of evaluators, however, and there is a lack of objective evaluation for proficiency in the microsurgical treatment of brain aneurysms. The authors present a new instrument, the Skill Assessment in Microsurgery for Brain Aneurysms (SAMBA) scale, which can be used similarly in a simulation model and in the treatment of unruptured middle cerebral artery (MCA) aneurysms to predict surgical performance; the authors also report on its validation. METHODS: The SAMBA scale was created by consensus among 5 vascular neurosurgeons from 2 different neurosurgical departments. SAMBA results were analyzed using descriptive statistics, Cronbach's alpha indexes, and multivariate ANOVA analyses (p < 0.05). RESULTS: Expert, intermediate-level, and novice surgeons scored, respectively, an average of 33.9, 27.1, and 16.4 points in the real surgery and 33.3, 27.3, and 19.4 points in the simulation. The SAMBA interrater reliability index was 0.995 for the real surgery and 0.996 for the simulated surgery; the intrarater reliability was 0.983 (Cronbach's alpha). In both the simulation and the real surgery settings, the average scores achieved by members of each group (expert, intermediate level, and novice) were significantly different (p < 0.001). Scores among novice surgeons were more diverse (coefficient of variation = 12.4). CONCLUSIONS: Predictive validation of the placenta brain aneurysm model has been previously reported, but the SAMBA scale adds an objective scoring system to verify microsurgical ability in this complex operation, stratifying proficiency by points. The SAMBA scale can be used as an interface between learning and practicing, as it can be applied in a safe and controlled environment, such as is provided by a placenta model, with similar results obtained in real surgery, predicting real surgical performance.

Human Placenta Simulator for Intracranial-Intracranial Bypass: Vascular Anatomy and 5 Bypass Techniques.

BACKGROUND: Intracranial-intracranial (IC-IC) bypass surgery involves the use of significant technical bimanual skills. Indications for this procedure are limited, so training in a simulator with brain vessels similarity could maintain microsurgical dexterity. Our goal is to describe the human placenta vascular anatomy to guide IC-IC bypasses apprenticeship. METHODS: Human placenta vascular anatomy was reported and validated with comparison to brain main vessels after studying the vascular tree of 100 placentas. Five simulated IC-IC bypasses (end to end, end to lateral, lateral to lateral, aneurysm bridge, and aneurysm exiting branch transposition) were developed and construct and concurrent validated. Statistical analysis using the t variance test was performed with a confidence interval of 0.95. RESULTS: A total of 1200 placenta vessels were used for test-retest validation with a reliability index of 0.95. All 100 human placentas were suitable to perform the 5 different bypasses. Construct validity showed a P < 0.005. Concurrent validity highlighted the technical differences among simulators. CONCLUSIONS: An ex vivo bypass model offers great similarity to main brain vessels with the possibility to practice a variety of IC-IC bypass techniques in a single simulator. Placenta vascular anatomy knowledge can improve laboratory microsurgical training.

Learning brain aneurysm microsurgical skills in a human placenta model: predictive validity.

OBJECTIVE Surgery for brain aneurysms is technically demanding. In recent years, the process to learn the technical skills necessary for these challenging procedures has been affected by a decrease in the number of surgical cases available and progressive restrictions on resident training hours. To overcome these limitations, surgical simulators such as cadaver heads and human placenta models have been developed. However, the effectiveness of these models in improving technical skills is unknown. This study assessed concurrent and predictive validity of brain aneurysm surgery simulation in a human placenta model compared with a "live" human brain cadaveric model. METHODS Two human cadaver heads and 30 human placentas were used. Twelve neurosurgeons participated in the concurrent validity part of this study, each operating on 1 human cadaver head aneurysm model and 1 human placenta model. Simulators were evaluated regarding their ability to simulate different surgical steps encountered during real surgery. The time to complete the entire aneurysm task in each simulator was analyzed. The predictive validity component of the study involved 9 neurosurgical residents divided into 3 groups to perform simulation exercises, each lasting 6 weeks. The training for the 3 groups consisted of educational video only (3 residents), human cadaver only (3 residents), and human placenta only (3 residents). All residents had equivalent microsurgical experience with superficial brain tumor surgery. After completing their practice training, residents in each of the 3 simulation groups performed surgery for an unruptured middle cerebral artery (MCA) aneurysm, and their performance was assessed by an experienced vascular neurosurgeon who watched the operative videos. RESULTS All human cadaver heads and human placentas were suitable to simulate brain aneurysm surgery. In the concurrent validity portion of the experiment, the placenta model required a longer time (p < 0.001) than cadavers to complete the task. The placenta model was considered more effective than the cadaver model in simulating sylvian fissure splitting, bipolar coagulation of oozing microvessels, and aneurysm neck and dome dissection. Both models were equally effective in simulating neck aneurysm clipping, while the cadaver model was considered superior for simulation of intraoperative rupture and for reproduction of real anatomy during simulation. In the predictive validity portion of the experiment, residents were evaluated for 4 tasks: sylvian fissure dissection, microvessel bipolar coagulation, aneurysm dissection, and aneurysm clipping. Residents trained in the human placenta simulator consistently had the highest overall performance scores when compared with those who had trained in the cadaver model and those who had simply watched operative videos (p < 0.001). CONCLUSIONS The human placenta biological simulator provides excellent simulation for some critical tasks of aneurysm surgery such as splitting of the sylvian fissure, dissection of the aneurysm neck and dome, and bipolar coagulation of surrounding microvessels. When performing surgery for an unruptured MCA aneurysm, residents who had trained in the human placenta model performed better than residents trained with other simulation scenarios/models. In this age of reduced exposure to aneurysm surgery and restrictions on resident working hours, the placenta model is a valid simulation for microneurosurgery with striking similarities with real surgery.

Occipital bi-transtentorial/falcine approach for falcotentorial meningioma: case report.

Lesions located in the bilateral posterior incisural space are difficult to treat due to limited exposure. The classical approaches to this area are limited for lesions located bilaterally and especially when the lesion extends also below the tentorium as it may occur with meningiomas. Kawashima et al. reported, in anatomic studies, a new occipital transtentorial approach: the occipital bi-transtentorial/falcine approach, to treat such lesions. We present a patient with a large falcotentorial meningioma, located bilaterally in the posterior incisural space. The occipital bi-transtentorial/falcine approach allowed an excellent surgical exposure and complete tumor removal with an excellent patient outcome.

[Decompressive craniectomy in children and adolescents with head injury: analysis of seven cases]. / Craniectomia descompressiva para tratamento da hipertensão intracraniana traumática em crianças e adolescentes: análise de sete casos.

INTRODUCTION: Decompressive craniectomy (DC) is a surgical technique used to treat patients with elevated intracranial pressure often found in head injury. Its indication remains a controversial issue in the pediatric population. OBJECTIVE: To report seven cases managed with this technique. METHOD: Retrospective study of seven patients, aged from 2 to 17 years, treated with unilateral DC due to increased intracranial pressure (ICP) as a consequence of head injury. All patients had ICP monitored post operatively and the DC classified as ultra-early (<6h), early (6-12h) or late (>24h) according to the time of its application. The minimum follow-up was six months. RESULTS: Patients were evaluated with CT scans and clinical exams, and graded according the Glasgow Outcome Scale (GOS). Three patients deceased (GOS1), one was in vegetative state (GOS2), two recovered but still requiring nursing care (GOS3 and 4), and one had a full recovery (GOS5) at hospital discharge. After six months the GOS2 and a GOS3 patients achieved full recovery (GOS5). Subdural collection (2), hydrocephalus (1) and superficial infection (1) occurred as complication. Two patients had autologous cranioplasty and the other two heterologous cranioplasty. CONCLUSION: Decompressive craniectomy remains a feasible treatment method to lower the ICP, but is not safe from complications. A multicentric study should be done for appropriate protocol treatment of pediatric patients.

Coconut Model for Learning First Steps of Craniotomy Techniques and Cerebrospinal Fluid Leak Avoidance.

INTRODUCTION: Neurosurgery simulation has gained attention recently due to changes in the medical system. First-year neurosurgical residents in low-income countries usually perform their first craniotomy on a real subject. Development of high-fidelity, cheap, and largely available simulators is a challenge in residency training. An original model for the first steps of craniotomy with cerebrospinal fluid leak avoidance practice using a coconut is described. MATERIAL AND METHODS: The coconut is a drupe from Cocos nucifera L. (coconut tree). The green coconut has 4 layers, and some similarity can be seen between these layers and the human skull. The materials used in the simulation are the same as those used in the operating room. PROCEDURE: The coconut is placed on the head holder support with the face up. The burr holes are made until endocarp is reached. The mesocarp is dissected, and the conductor is passed from one hole to the other with the Gigli saw. The hook handle for the wire saw is positioned, and the mesocarp and endocarp are cut. After sawing the 4 margins, mesocarp is detached from endocarp. Four burr holes are made from endocarp to endosperm. Careful dissection of the endosperm is done, avoiding liquid albumen leak. The Gigli saw is passed through the trephine holes. Hooks are placed, and the endocarp is cut. After cutting the 4 margins, it is dissected from the endosperm and removed. The main goal of the procedure is to remove the endocarp without fluid leakage. DISCUSSION: The coconut model for learning the first steps of craniotomy and cerebrospinal fluid leak avoidance has some limitations. It is more realistic while trying to remove the endocarp without damage to the endosperm. It is also cheap and can be widely used in low-income countries. However, the coconut does not have anatomic landmarks. The mesocarp makes the model less realistic because it has fibers that make the procedure more difficult and different from a real craniotomy. CONCLUSION: The model has a potential pedagogic neurosurgical application for freshman residents before they perform a real craniotomy for the first time. Further validity is necessary to confirm this hypothesis.

Face, Content, and Construct Validity of Brain Tumor Microsurgery Simulation Using a Human Placenta Model.

BACKGROUND: Brain tumors are complex 3-dimensional lesions. Their resection involves training and the use of the multiple microsurgical techniques available for removal. Simulation models, with haptic and visual realism, may be useful for improving the bimanual technical skills of neurosurgical residents and neurosurgeons, potentially decreasing surgical errors and thus improving patient outcomes. OBJECTIVE: To describe and assess an ex vivo placental model for brain tumor microsurgery using a simulation tool in neurosurgical psychomotor teaching and assessment. METHODS: Sixteen human placentas were used in this research project. Intravascular blood remnants were removed by continuous saline solution irrigation of the 2 placental arteries and placental vein. Brain tumors were simulated using silicone injections in the placental stroma. Eight neurosurgeons and 8 neurosurgical residents carried out the resection of simulated tumors using the same surgical instruments and bimanual microsurgical techniques used to perform human brain tumor operations. Face and content validity was assessed using a subjective evaluation based on a 5-point Likert scale. Construct validity was assessed by analyzing the surgical performance of the neurosurgeon and resident groups. RESULTS: The placenta model simulated brain tumor surgical procedures with high fidelity. Results showed face and content validity. Construct validity was demonstrated by statistically different surgical performances among the evaluated groups. CONCLUSION: Human placentas are useful haptic models to simulate brain tumor microsurgical removal. Results using this model demonstrate face, content, and construct validity.

Face, content, and construct validity of human placenta as a haptic training tool in neurointerventional surgery.

OBJECT The development of neurointerventional treatments of central nervous system disorders has resulted in the need for adequate training environments for novice interventionalists. Virtual simulators offer anatomical definition but lack adequate tactile feedback. Animal models, which provide more lifelike training, require an appropriate infrastructure base. The authors describe a training model for neurointerventional procedures using the human placenta (HP), which affords haptic training with significantly fewer resource requirements, and discuss its validation. METHODS Twelve HPs were prepared for simulated endovascular procedures. Training exercises performed by interventional neuroradiologists and novice fellows were placental angiography, stent placement, aneurysm coiling, and intravascular liquid embolic agent injection. RESULTS The endovascular training exercises proposed can be easily reproduced in the HP. Face, content, and construct validity were assessed by 6 neurointerventional radiologists and 6 novice fellows in interventional radiology. CONCLUSIONS The use of HP provides an inexpensive training model for the training of neurointerventionalists. Preliminary validation results show that this simulation model has face and content validity and has demonstrated construct validity for the interventions assessed in this study.

[Supratentorial-infraoccipital (or occipitopolar) approach: clinical and anatomical study]. / Acesso supratentorial-infraoccipital ou occipitopolar: estudo clínico e anatômico.

Twenty-two patients harboring tumors or vascular lesions (AVMs and aneurysms) located at the posterior aspect of the parahipocampal gyrus and the pulvinar of thalamus operated by supratentorial-infraoccipital approach were analysed. Total resection was achieved in all five AVM patients as well as in six out of fifteen tumor patients. This approach was performed in five anatomical specimens (ten approaches); It results, along with the surgical results, allow this approach to be considered a good option for lesions of the pulvinar of thalamus and postero-medial temporal lobe which are evident at the transverse fissure.

Validation of the Objective Structured Assessment of Technical Skill in Brasil

SUMMARY BACKGROUND The aim of this study was to perform a cross-cultural adaptation of the Objective Structured Assessment of Technical Skill (OSATS) tool into Brazilian Portuguese and to determine its reproducibility and validity in Brasil. METHODS A Brazilian Portuguese version of OSATS was created through a process of translation, back-translation, expert panel evaluation, pilot testing, and then its validation. For the construct and the concurrent validities, twelve participants were divided into a group of six experts and six novices, who had to perform tasks on a simulation model using human placentas. Each participant was filmed, and two blinded raters would then evaluate their performance using the traditional subjective method and then the Brazilian Portuguese version of OSATS. RESULTS The Brazilian Portuguese version of OSATS had the face, content, construct, and concurrent validities achieved. The average experts' score and standard deviations were 34 and 0.894, respectively, for Judge 1 and 34.33 and 0.816 for Judge 2. In the case of novices, it was 13.33 and 2.388 for Judge 1 and 13.33 and 3.204 for Judge 2. The concordance between the judges was evident, with the Correlation Coefficient (Pearson) of 0.9944 with CI 95% between 0.9797 and 0.9985, with p < 10-10, evidencing the excellent reproducibility of the instrument. CONCLUSION This preliminary study suggests that the Brazilian Portuguese version of OSATS can reliably and validly assess surgical skills in Brasil.

RESUMO OBJETIVOS Objetivou-se com este trabalho adaptar transculturalmente o instrumento Objective Structured Assessment of Technical Skill (Osats) para o português-brasileiro e validá-lo no Brasil. MÉTODOS Uma versão em português-brasileiro do Osats foi criada por meio de um processo de tradução, retrotradução, versão consensual por um comitê de especialistas e pré-teste, seguido da etapa de validação. Para validades de constructo e concorrente, foram recrutados 12 participantes da Universidade Federal de Minas Gerais, divididos em um grupo de seis especialistas e um grupo de seis novatos, que tiveram de realizar tarefas em modelos de simulação utilizando placentas humanas. Cada participante foi filmado em anonimato e dois examinadores avaliaram os seus desempenhos usando o método tradicional subjetivo e depois a versão em português-brasileiro do Osats. RESULTADOS A versão em português-brasileiro do Osats alcançou as validades de face, de conteúdo, de constructo e concorrente. A média e o desvio padrão das pontuações atribuídas aos especialistas foram, respectivamente, 34 e 0,894, para o Juiz 1 e 34,33 e 0,816 para o Juiz 2. No caso dos novatos, foram 13,33 e 2,338 para o Juiz 1 e 13,33 e 3,204 para o Juiz 2. O Coeficiente de Correlação (de Pearson) entre os dois juízes foi de 0,9944 com IC 95% entre 0,9797 e 0,9985, com p<10-10, evidenciando a excelente reprodutibilidade do instrumento. CONCLUSÃO A versão em português-brasileiro do Osats manteve-se equivalente ao instrumento original e foi validada. Assim, pode ser usada para avaliar a performance operatória dos residentes em cirurgia no Brasil.