Principles and strategies for step-by-step AVM excision

Arteriovenous malformations (AVMs) are some of the most challenging surgical entities. Like any challenging surgical procedure, AVM surgery is a series of basic but fundamental steps, each with its own nuances. Despite a myriad of published material regarding AVMs, there are few succinct illustrated summaries of these steps with an accompanying elucidation of the most common pitfalls. This paper provides a step-by-step description and illustration of the basic surgi-cal principles of AVM microsurgical resection, focusing on the main key points and addressing the critical issues that surround this surgery. Deep anatomical knowledge and presurgical planning of these basic steps, combined with good contingency management skills, are paramount for an effective and safe AVM surgery

How I do it: resection of spinal cord cavernous malformation

Background Spinal cord cavernous malformations (CMs) account for 5 to 12% of all spinal vascular malformations. Surgical removal is indicated in symptomatic patients, especially if the CM comes close to the dorsal or lateral surface of the spinal cord. Spinal cord CMs pose critical challenges for the potential of severe disabling complications. Method We described the step-by-step surgical principles of spinal cord CM microsurgical resection. The main surgical steps are also illustrated in an accompanying operative video. Conclusion Pre-surgical planning of the basic steps and good contingency management skills are paramount for an effective and safe spinal cord CM excision

Endoscopic endonasal surgical anatomy of the optic canal: key anatomical relationships between the optic nerve and ophthalmic artery

Purpose A detailed understanding of the neurovascular relationships between the optic nerve (ON) and the ophthalmic artery (OA) in the optic canal (OC) is paramount for safe surgery. We focused on the neurovascular anatomy of this area from both an endoscopic endonasal and transcranial trajectories to compare the surgical exposures and perspectives offered by these different views and provide recommendations to increase the intraoperative safety. Methods Twenty sides of ten formalin-fixed, latex-injected head specimens were utilized. The surgical anatomy and anatomical relationships of the OA in relationship to the ON along their intracranial and intracanalicular segments was studied from endoscopic endonasal and transcranial perspectives. Results Three types of OA-ON relationships at the origin of the OA were identified: inferomedial (type 1, 35%), inferior (type 2, 55%), and inferolateral (type 3, 10%). The endoscopic endonasal trajectory offers an inferomedial perspective of the ON-OA neurovascular complex, in which the OA, especially when located inferomedially, is first encountered. When comparing with the transcranial view, all OA were covered by the nerve, type 1 was located below the medial third, type 2 below the middle third, and type 3 below the lateral third of the OC. The mean extension of the intracanalicular portion of both OA and ON was 8.9 mm, while the intracranial portion of the OA and ON were 9.3 mm and 12.4 mm, respectively. The OA, endoscopically, is located within the inferior half of the OC, and occupies 39%, 43%, and 42% of the OC height at its origin, mid, and end points, respectively. The mean distance between the superior margin of the OC at its origin and superior margin of the OA is 1.4 mm. Conclusions Detailed anatomical understanding of the OC, and the ON and OA at their intracranial and intracanalicular segments is paramount to safe surgery. When opening the OC dura endoscopically, our results suggest that a medial incision along the superior third of the OC with a proximal to distal direction is recommended to avoid injury of the OA

The endonasal midline inferior intercavernous approach to the cavernous sinus: technical note, cadaveric step-by-step illustration, and case presentation

Purpose Traditional endoscopic endonasal approaches to the cavernous sinus (CS) open the anterior CS wall just medial to the internal carotid artery (ICA), posing risk of vascular injury. This work describes a potentially safer midline cellar entry point for accessing the CS utilizing its connection with the inferior intercavernous sinus (IICS) when anatomically present.Methods The technique for the midline intercavernous dural access is described and depicted with cadaveric dissections and a clinical case.Results An endoscopic endonasal approach exposed the periosteal dural layer of anterior sella and CS. The IICS was opened sharply in midline through its periosteal layer. The feather knife was inserted and advanced laterally within the IICS toward the anterior CS wall, thereby gradually incising the periosteal layer of the IICS. The knife was turned superiorly then inferiorly in a vertical direction to open the anterior CS wall. This provided excellent access to the CS compartments, maintained the meningeal layer of the IICS and the medial CS wall, and avoided an initial dural incision immediately adjacent to the ICA.Conclusion The midline intercavernous dural access to the CS assisted by a 90 degrees dissector-blade is an effective modification to previously described techniques, with potentially lower risk to the ICA

Learning to Identify Historical Figures for Timeline Creation from Wikipedia Articles

Abstract. This paper addresses a central sub-task of timeline creation from historical Wikipedia articles: learning from text which of the per-son names in a textual article should appear in a timeline on the same topic. We first process hundreds of timelines written by human experts and related Wikipedia articles to construct a corpus that can be used to evaluate systems that create history timelines from text documents. We then use a set of features to train a classifier that predicts the most important person names, resulting in a clear improvement over a com-petitive baseline.

Surgical Anatomy and Approaches of the Anterior Cranial Fossa from a Transcranial and Endonasal Perspective

The anterior cranial fossa (ACF) is a complex anatomical region that can be affected by a broad spectrum of pathology. For the surgical treatment of these lesions, many approaches have been described, each of them with different scope and potential surgical complications, often associated with significant morbidity. Traditionally, tumors involving the ACF have been operated by transcranial approaches; however, in the last two decades, endoscopic endonasal approaches (EEAs) have been gaining popularity. In this work, the authors review and describe the anatomical aspects of the ACF and the technical nuances of transcranial and endoscopic approaches for tumors located in this region. Four approaches were performed in embalmed cadaveric specimens and the key steps were documented. Four illustrative cases of ACF tumors were selected to demonstrate the clinical application of anatomical and technical knowledge, which are essential in the preoperative decision-making process

Anatomoradiological comparison between the minipterional and supraorbital eyebrow approaches to the interpeduncular region

OBJECTIVE Advances in surgical technology and microneurosurgery have led to increased utilization of so-called minimally invasive approaches, including the supraorbital eyebrow (SE) and minipterional (MPT) approaches for lesions involving the interpeduncular region. This study aimed to describe and compare anatomical landmarks, along with highlighting the advantages and disadvantages of the SE and MPT approaches to the interpeduncular region. METHODS Ten formalin-fixed, latex-injected cadaveric specimens were used to perform bilateral SE and MPT approaches to the interpeduncular region. The operative depth of each approach to key anatomical landmarks was measured. Forty-five axial thin-slice computed tomography studies were reviewed to calculate the operative angles, with consideration of the midline as a reference. A 3D interactive anatomical model generated through the photogrammetry scanning technique was described. RESULTS The depths of the operative corridors of the SE and MPT approaches to the interpeduncular fossa were 83.4 ± 1.8 mm and 67.7 ± 3.2 mm, respectively (p < 0.001). The mean angle of the MPT approach to the interpeduncular fossa was significantly wider than the one provided by the SE approach (39.9° ± 5.1° vs 28.4° ± 3.6°, p < 0.001). The interpeduncular region can consistently be accessed through the carotid-oculomotor triangle with the SE approach, as well as with the MPT approach. Furthermore, the SE route offered adequate access to the interpeduncular fossa through the opticocarotid triangle. The MPT route provided direct access to the upper prepontine cistern and anterior mesencephalic zone (AMZ). CONCLUSIONS The MPT approach provides a wider and shorter operative corridor and can be employed for lesions in the interpeduncular region with extension to the prepontine cistern and ventrolateral midbrain lesions requiring access through the AMZ. The SE approach is better suited for ventromedial midbrain lesions requiring access via the interpeduncular fossa safe entry zone. Additional studies analyzing these approaches in a clinical setting will help to delineate their reliability and efficacy