The peridural membrane of the spinal canal: a critical review.

There exists substantial evidence that a peridural membrane (PM) is present in the spinal canal of humans and, like the pleura and peritoneum, has one or more physiologic functions. Innervation of the PM suggests that it may become a source of pain if injured. Although debated, the physiology of this structure has important implications with respect to neuraxial distribution of drugs and for back and radiating pain. This review, separated into embryological, anatomic, and physiologic discussions, provides an in-depth summary of the observations of this connective tissue. The discrepancies between accounts are highlighted within each section. Focused research to clearly elucidate the true nature of the PM, especially as related to neuraxial distribution of drugs and back and radiating pain, is warranted.

Recanalization therapy for acute ischemic stroke, part 2: mechanical intra-arterial technologies.

Stroke therapy has been revolutionized in the past two decades with the widespread implementation of chemical thrombolysis for acute stroke. However, chemical thrombolysis continues to be limited in its efficacy secondary to relatively short time windows and a high associated risk of hemorrhage. In an attempt to minimize hemorrhagic complications and extend the available therapeutic window, mechanical devices designed specifically for thrombus removal, clot obliteration, and arterial revascularization have experienced a recent surge in development and utilization. As such, chemical thrombolytics now represent only one of many options in acute stroke therapy. These new mechanical devices have extended the potential treatment window and now provide alternatives to patients who do not respond to conventional intravenous thrombolysis. This review will discuss the development of these devices, supporting literature, and the individual strengths that each engenders towards a life-saving therapy for stroke.

Surgical checklists: A detailed review of their emergence, development, and relevance to neurosurgical practice.

In the fall of 1999, the Institute of Medicine released "To Err is Human: Building a Safer Health System," a sobering report on the safety of the American healthcare industry. This work and others like it have ushered in an era where the science of quality assurance has quickly become an integral facet of the practice of medicine. One critical component of this new era is the development, application, and refinement of checklists. In a few short years, the checklist has evolved from being perceived as an assault on the practitioner' integrity to being welcomed as an important tool in reducing complications and preventing medical errors. In an effort to further expand the neurosurgical community's acceptance of surgical checklists, we review the rationale behind checklists, discuss the history of medical and surgical checklists, and remark upon the future of checklists within our field.

Intraluminal middle cerebral artery occlusion (MCAO) model for ischemic stroke with laser doppler flowmetry guidance in mice.

Stroke is the third leading cause of death and the leading cause of disability in the world, with an estimated cost of near $70 billion in the United States in 2009. The intraluminal middle cerebral artery occlusion (MCAO) model was developed by Koizumi in 1986 to simulate this impactful human pathology in the rat. A modification of the MCAO method was later presented by Longa. Both techniques have been widely used to identify molecular mechanisms of brain injury resulting from ischemic stroke and potential therapeutic modalities. This relatively noninvasive method in rats has been extended to use in mice to take advantage of transgenic and knockout strains. To model focal cerebral ischemia, an intraluminal suture is advanced via the internal carotid artery to occlude the base of the MCA. Retracting the suture after a specified period of time mimics spontaneous reperfusion, but the suture can also be permanently retained. This video will be demonstrating the two major approaches for performing intraluminal MCAO procedure in mice in a stepwise fashion, as well as providing insights for potential drawbacks and pitfalls. The ischemic brain tissue will subsequently be stained by 2,3,5-triphenyltetrazolium chloride (TTC) to evaluate the extent of cerebral infarction.

A simple technique for morphological measurement of cerebral arterial circle variations using public domain software (Osiris).

This article describes a straightforward method to measure the dimensions and identify morphological variations in the cerebral arterial circle using the general-purpose software program Osiris. This user-friendly and portable program displays, manipulates, and analyzes medical digital images, and it has the capability to determine morphometric properties of selected blood vessels (or other anatomical structures) in humans and animals. To ascertain morphometric variations in the cerebral arterial circle, 132 brains of recently deceased fetuses, infants, and adults were dissected. The dissection procedure was first digitized, and then the dimensions were measured with Osiris software. Measurements of each vessel's length and external diameters were used to identify and classify morphological variations in the cerebral arterial circle. The most commonly observed anatomical variations were uni- and bilateral hypoplasia of the posterior communicating artery. This study demonstrates that public domain software can be used to measure and classify cerebral arterial circle vessels. This method could be extended to examine other anatomical regions or to study other animals. Additionally, knowledge of variations within the circle could be applied clinically to enhance diagnostic and treatment specificity.

Intracranial stents for treatment of acute ischemic stroke: evolution and current status.

BACKGROUND: Intravascular stents have been applied to treat a variety of pathophysiologic conditions. With advances in stent design and delivery, stenting has become a viable treatment option in neurovascular disease. Recently, intracranial arterial stenting has received increasing interest as a modality to rapidly and effectively recanalize affected vessels in the setting of acute ischemic stroke. METHODS: To examine the potential of stenting procedures for stroke, we compiled and analyzed relevant experimental and clinical studies in the available databases. RESULTS: Our resulting discussion covers the brief history of stents, from their initial inception in the 1960s, to the developments of interventional cardiology, and finally to the treatment of acute occlusions of the neurovasculature. We also detail technological advances that have improved stent delivery to intracranial arteries and review the several clinical studies that feature stenting for the treatment of acute ischemic stroke. CONCLUSION: Numerous clinical studies have revealed that stents are a quick and efficacious endovascular tool for acute ischemic stroke treatment. It appears likely that issues regarding design, safety, and feasibility of stent-based devices will experience further improvement and refinement, and from fruitful criticism of existing technologies and techniques, along with lessons from past mistakes, will arise safer and more effective devices.

Impact of intracranial self-expanding stents in the treatment of acute ischemic stroke: efficacy and limitations.

In recent years, endovascular self-expanding stents have become a viable option for neurointerventionalists treating acute ischemic stroke. Timely intervention for stroke could mean the difference between complete recovery and significant morbidity or death. Since 2006, a handful of clinical trials have demonstrated the potential of self-expanding stents in dependably achieving quick revascularization. These devices are expanding in utilization as new designs offer greater procedural flexibility and better clinical results. We discuss these clinical investigations, focusing on the procedural capabilities and limitations of each self-expanding stent design.