BACKGROUND The Smith-Robinson1 approach (SRA) is the most widely used route to access the anterior cervical spine. Although several authors have described this approach, there is a lack of the stepwise anatomic description of this operative technique. With the advent of new technologies in neuroanatomy education, such as volumetric models (VMs), the understanding of the spatial relation of the different neurovascular structures can be simplified. OBJECTIVE To describe the anatomy of the SRA through the creation of VMs of anatomic dissections. METHODS A total of 4 postmortem heads and a cervical replica were used to perform and record the SRA approach to the C4-C5 level. The most relevant steps and anatomy of the SRA were recorded using photogrammetry to construct VM. RESULTS The SRA was divided into 6 major steps: positioning, incision of the skin, platysma, and muscle dissection with and without submandibular gland eversion and after microdiscectomy with cage positioning. Anatomic model of the cervical spine and anterior neck multilayer dissection was also integrated to improve the spatial relation of the different structures. CONCLUSION In this study, we review the different steps of the classic SRA and its variations to different cervical levels. The VMs presented allow clear visualization of the 360-degree anatomy of this approach. This new way of representing surgical anatomy can be valuable resources for education and surgical planning.

No abstract

No abstract

Objectives: Several papers have been published relating the Idiopathic Intracranial Hypertension Syndrome (HTII) to the Arnold Chiari type I malformation (AC1M). Both entities have clinical and demographic similarities, a poorly defined etiology and, sometimes common therapeutic posibilities. A correlation between both entities has been suggested, especially in a subgroup of patients in whom posterior fossa decompression surgery fails. With regard to a case, we reviewed the literature and proposed our hypothesis about the origin of Chiari-HTII syndrome and its therapeutic possibilities. Case presentation: A 41year-old patient with mild obesity, menstrual abnormalities and empty Sella Turcicae, was operated on with an AC1M associating basilar impression and syringomyelia causing all together a centromedullary syndrome. After posterior fossa decompression surgery and successful arthrodesis, she improved in the immediate postoperative period. Nevertheless, she soon developed symptoms of intracranial hypertension (ICH), and showed increased opening pressure in lumbar puncture compatible with HTII syndrome. A ventriculoperitoneal shunt (VPS) was implanted with clinical improvement and 12 months later the syringomyelia was absent on in the magnetic resonance (MRI). Conclusion: The Chiari I-HTII syndrome is described as the coexistence of ICH symptoms after failed posterior fossa surgery, in patients with no flow MRI anomalies, and increased opening pressure at the lumbar puncture. In our experience, both entities seem to overlap in a common syndrome and must be taken into account, especially in patients with atypical onset of symptoms or patients in whom conservative treatment fails.

OBJECTIVE The lateral posterior choroidal artery (LPChA) should be a major surgical consideration in the microsurgical management of lateral ventricular tumors. Here the authors aim to delineate the microsurgical anatomy of the LPChA by using anatomical microdissections. They describe the trajectory, segments, and variations of the LPChA and discuss the surgical implications when approaching the choroid plexus using different routes. METHODS Twelve colored silicone–injected, lightly fixed, postmortem human head specimens were prepared for dissection. The origin, diameter, trunk, course, segment, length, spatial relationships, and anastomosis of the LPChA were investigated. The surgical landmarks of 4 different approaches to the LPChA were also examined thoroughly. RESULTS The LPChA was present in 23 hemispheres (96%), and in 14 (61%) it originated from the posterior segment of the P2 (i.e., P2P); most commonly (61%) the LPChA had 2 trunks, and in 17 hemispheres (74%) it had a C-shaped trajectory. According to its course, the authors divided the LPChA into 3 segments: 1) cisternal, from PCA to choroidal fissure (length 10.6 ± 2.5 mm); 2) forniceal, starting at the choroidal fissure, 8.2 ± 5.7 mm posterior to the inferior choroidal point, and terminating at the posterior level of the choroidal fissure (length 28.7 ± 6.8 mm); and 3) pulvinar, starting at the posterior choroidal fissure and terminating in the pulvinar (length 5.9 ± 2.2 mm). The LPChA was divided into 3 patterns according to its entrance into the choroidal fissure: A (anterior) 78%; B (posterior) 13%; and C (mixed) 9%. The transsylvian trans–limen insulae approach provided the best exposure for cisternal and proximal forniceal segments; the lateral transtemporal approach facilitated a more direct approach to the forniceal segment, including cases with posterior entrance; the transparietal transcortical and contralateral posterior interhemispheric transfalcine transprecuneus approaches provided direct access to the pulvinar segment of the LPChA and to the posterior forniceal segment, including cases with posterior choroidal entrance. CONCLUSIONS The LPChA typically runs in the medial border of the choroid plexus, which may facilitate its recognition during surgery. The distance between the AChA at the inferior choroidal point and the LPChA is a valuable reference during surgery, but there are cases of posterior choroidal entrance. Most frequently, there are 2 or more LPChA trunks, which makes possible the sacrifice of one trunk feeding the tumor while preserving the other that provides supply to relevant structures. The intraventricular approaches can be selected based on the tumor location and the LPChA anatomy.