Background and Purpose— Aging affects elastin, a key component of the arterial wall integrity and functionality. Elastin degradation in cerebral vessels is associated with cerebrovascular disease. The goal of this study is to assess the biomechanical properties of human cerebral arteries, their composition, and their geometry, with particular focus on the functional alteration of elastin attributable to aging. Methods— Twelve posterior cranial arteries obtained from human cadavers of 2 different age groups were compared morphologically and tested biomechanically before and after enzymatic degradation of elastin. Light, confocal, and scanning electron microscopy were used to analyze and determine structural differences, potentially attributed to aging. Results— Aging affects structural morphology and the mechanical properties of intracranial arteries. In contrast to main systemic arteries, intima and media thicken while outer diameter remains relatively constant with age, leading to concentric hypertrophy. The structural morphology of elastin changed from a fiber network oriented primarily in the circumferential direction to a more heterogeneously oriented fiber mesh, especially at the intima. Biomechanically, cerebral arteries stiffen with age and lose compliance in the elastin dominated regime. Enzymatic degradation of elastin led to loss in compliance and stiffening in the young group but did not affect the structural and material properties in the older group, suggesting that elastin, though present in equal quantities in the old group, becomes dysfunctional with aging. Conclusions— Elastin loses its functionality in cerebral arteries with aging, leading to stiffer less compliant arteries. The area fraction of elastin remained, however, fairly constant. The loss of functionality may thus be attributed to fragmentation and structural reorganization of elastin occurring with age.

The invention of new techniques for surgery and interventional radiology demand improved training for ongoing specialists. The Anatomical Institutes in Switzerland support these requirements by establishing hands-on practical training courses by using new procedures for cadaver embalming and model construction. Improvements allow courses to provide students with more realistic simulations of both established and experimental surgical methods. Through these changes, the value of in-depth gross anatomy is enhanced as a topic of fundamental importance for the postgraduate medical and surgical curriculum. The web site www.unifr.ch/sgahe/snga.html contains information on courses using the Thiel embalming solution. Details about training courses in Switzerland using anatomical models are available at www.heartlab.org, www.vascular-international.org, and www.elastrat.com. Anat Rec (New Anat) 265:254 -256, 2001.

Knowledge of the CSF pathways holds implications for our ability to understand, prognose, and even treat diseases related to CSF circulation and so is a matter of considerable relevance to neuroradiology and neurology.

In this model, despite a shorter insertion time, the NT produced more lesions and more failures than the ST.

Several factors made hNOTES-RYGBP very challenging and time-consuming. A lack of proper instrumentation resulting in insufficient tissue traction, countertraction, and instrument manipulation complicated several steps during the procedure. A combination of flexible with rigid endoscopic techniques offers specific advantages for components of this type of surgery. Changes in instrument design are required to improve more complex endosurgical procedures.