Scleroderma, or systemic sclerosis, is an autoimmune disorder affecting connective tissues, including blood vessels. Although the exact mechanism is not understood, it results in the production of an ...abnormal amount of collagen. Cases have been reported in which patients with scleroderma also had intracranial aneurysms. We wish to gain insight into any potential association between the 2 diseases.
We reviewed the literature of scleroderma cases with cerebral aneurysms and added our own case, focusing on patient and aneurysm characteristics. Including the present case, this paper pertains to 11 cases with 26 aneurysms. Fifty-five percent had multiple aneurysms, of which two thirds had >2. When data were available, 35% of aneurysms were ≥1 cm, 12% of which were giant. Four aneurysms were fusiform (15%). Patients presented with subarachnoid hemorrhage in 45% of cases.
Scleroderma may lead to the formation of an aneurysm, and the abnormal growth of collagen may protect it from early rupture, allowing it to reach a large size.
Purpose
The ophthalmic artery (OA) has one of the most complex anatomy and the most fascinating embryological development.
Methods
The complexity of the embryologic development of the OA resides in ...the implication of three different embryological systems: the carotid system, the stapedial system, and the ventral pharyngeal system.
Results
This explains very well the numerous variations in origin of the OA and the importance of vascular anastomoses developed with branches of the external carotid artery and with the middle meningeal artery.
Conclusion
In this review, authors propose a comprehensive description of different hypotheses on the embryologic development of the OA and, in a second part, explain all anatomical variations and clinical implications of this artery.
Blister aneurysms of the supraclinoid part of the internal carotid artery (ICA) are known for their high morbidity and mortality rates related to treatment, regardless of whether the treatment is ...surgical or endovascular. However, this grim prognosis is based on results that indiscriminately group all blister aneurysms together without taking into account the heterogeneous appearance of these lesions. The goal of this study was 2-fold: to determine whether different blister aneurysm morphologies present different pitfalls, which would then require different surgical strategies, as well as to determine whether there are identifiable subgroups of these types of aneurysms based on morphology.
The authors reviewed the charts, cerebral catheter angiograms, surgical reports, and intraoperative videos of all ICA blister aneurysms treated surgically at the Centre Hospitalier de l'Université de Montréal from 2005 to 2012 to investigate whether there was a relationship between morphology and pitfalls, and whether different surgical strategies had been used according to these pitfalls. During this review process the authors noted 4 distinct morphological aspects. These 4 aspects led to a review of the English and French literature on blister aneurysms in which imaging was available, to determine whether other cases could also be classified into the same 4 subgroups based on these morphological aspects.
The retrospective review of the authors' series of 10 patients allowed a division into 4 distinct subtypes: Type I (classic), Type II (berry-like), Type III (longitudinal), and Type IV (circumferential). These subtypes may at times be progressive stages in the arterial anomaly, and could represent a continuum. Each subtype described in this paper presented its own pitfalls and required specific surgical adaptations. Upon reviewing the literature the authors retained 35 studies involving a total of 61 cases of blister aneurysms, and all cases were able to be classified into 1 of these 4 distinct subtypes.
Although they share some common characteristics, blister aneurysms may be divided into distinct subtypes, suggestive of a continuum. Such a classification with a detailed description of each type of blister aneurysm would allow for better recognition to anticipate complications during intervention and better assess the different treatment strategies according to the subtypes.
Background
Vertebro-PICA aneurysms may be challenging because of their relationship with the brainstem and the lower cranial nerves, especially when the vertebral artery is tortuous and the aneurysm ...is located in front of the brainstem, contralaterally to the parent vertebral artery. We describe the surgical technique for safe approach.
Method
Cadaveric dissection performed by the authors, provided comprehensive understanding of relevant anatomy. Intraoperative photos and videos show clipping of the aneurysm using a combined midline and far-lateral suboccipital craniotomy with a para-condylar extension. The literature reviews potential complications.
Conclusion
This combined approach allows safe clipping of such PICA aneurysms.
Background and purpose
Internal carotid artery (ICA) agenesis is a rare anatomical variant that can involve different segments of the ICA. Although many authors proposed their own classifications of ...this variant basing on different criteria, none of these allows to include all the cases described in the literature. The aim of the authors is to propose a new classification that allows to include all cases of ICA agenesis described until now.
Materials and methods
The study is based on the review of all the cases of ICA agenesis described in the literature and of the classifications already proposed. After the analysis of these cases, we looked for the limits of each classification to elaborate a new more complete one.
Results
We found 228 cases of ICA agenesis. Among them 40 were not includible in the existing classifications. For this reason, we proposed a new classification based on the type of flow compensation and on the embryological events that determine the different variants. The flow is compensated in Type I by the Circle of Willis; in Type II by the non-regression of an embryonic artery; in Type III by the presence of an arterio-arterial anastomosis and in Type IV by external-internal carotid arteries anastomoses.
Conclusion
After the literature review, we proposed a new comprehensive classification based on the detailed analysis of arterial embryology. Even if all the embryological details that determine this complex variant are not completely understood yet, this classification allows to include all the cases described in literature.
The persistent trigeminal artery is the most frequent of the persistent embryonic carotid-basilar artery anastomoses. In the literature, it has most often been described in relation to ...cerebrovascular pathologies such as aneurysms, vascular nerve compression, trigeminal cavernous fistulas, and thromboembolic ischemia. Its role as collateral circulation, thus supplying brain perfusion during main arterial trunk occlusion, has seldom been described. We describe the case of a patient who presented with a stroke due to a traumatic dissection of the internal carotid artery at the neck, in which the infarction may have been limited by a persistent trigeminal artery.
•The osteology and anatomy of the muscles and ligaments of the Craniocervical Junction (CCJ) is reviewed.•The surgical anatomy is discussed from the perspective of three surgical approaches; the Far ...Lateral, Anterolateral, and Endoscopic Endonasal.•Knowledge of the surgical anatomy of the CCJ is paramount to the preservation of the vertebral artery during surgery in this region.
An in-depth understanding of the anatomy of the craniocervical junction (CCJ) is indispensable in skull base neurosurgery. In this paper, we discuss the osteology of the occipital bone, the atlas (C1) and axis (C2), the ligaments and the muscle anatomy of the CCJ region and their relationships with the vertebral artery. We will also discuss the trajectory of the vertebral artery and review the anatomy of the jugular foramen and lower cranial nerves (IX to XII). The most important surgical approaches to the CCJ, including the far lateral approach, the anterolateral approach of Bernard George and the endoscopic endonasal approach, will be discussed to review the surgical anatomy.
Purpose
There is no objective way to measure the amount of manipulation and retraction of neural tissue by the surgeon. Our goal is to develop metrics quantifying dynamic retraction and manipulation ...by instruments during neurosurgery.
Methods
We trained a convolutional neural network (CNN) to analyze microscopic footage of neurosurgical procedures and thereby generate metrics evaluating the surgeon’s dynamic retraction of brain tissue and, using an object tracking process, evaluate the surgeon’s manipulation of the instruments themselves. U-Net image segmentation is used to output bounding polygons around cerebral parenchyma of interest, as well as the vascular structures and cranial nerves. A channel and spatial reliability tracker framework is used in conjunction with our CNN to track desired surgical instruments.
Results
Our network achieved a state-of-the-art intersection over union (
72.64
%
) for biological tissue segmentation. Multivariate statistical analysis was used to evaluate dynamic retraction, tissue handling, and instrument manipulation.
Conclusion
Our model enables to evaluate dynamic retraction of soft tissue and manipulation of instruments during a surgical procedure, while accounting for movement of the operative microscope. This model can potentially provide the surgeon with objective feedback about the movement of instruments and its effect on brain tissue.
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