In recent years, technical advances have allowed more significant structural spine surgery through small access portals. Minimally invasive spinal surgery (MISS) is commonly thought of as posterior approaches using muscle dilating tubular retraction systems, but these approaches are best suited to a single spinal level and require bony disruption at each level treated. Access through the sacral hiatus with a flexible endoscope allows an alternative, longitudinal approach to the entire lumbar epidural space. Surgical instruments can be introduced through the endoscope, including laser waveguide fibers. In this article, we expand upon previous reports and describe the combined clinical results of endoscopic laser decompression in 154 patients from 8 centers. All cases of anterior endoscopic neural decompression via sacral laminotomy between December 2009 and May 2011 were reviewed at participating centers and sent a follow‐up questionnaire. One hundred and fifty‐four cases were identified. There was a significant improvement in disability caused by low‐back and/or leg pain as measured by the RMQ. The postoperative level of pain improved from 7.5 to 3.4. By the MacNab scale, success was achieved in 82%. Overall, the patients demonstrated significant clinical recovery and improvement in both quality of life and overall pain levels.
Since its inception in the 1970s, peripheral neuromodulation has become an increasingly common procedure to treat chronic neuropathic disorders. Historically, peripheral nerve stimulation (PNS) originated with the placement of large surface cuff electrodes, which was refined by the introduction of functional nerve mapping with circumferential electrical stimulation. This substantially improved the targeting of sensory fascicles. Surgical placement of spinal cord stimulation (SCS) 'button type' paddle electrodes was replaced when the introduction of percutaneous cylindrical SCS electrodes expanded the spectrum of PNS applications and improved the ability to target afferent sensory fibers as well as reducing the complication rate. To further refine functional mapping for the placement of these percutaneous electrodes, radiofrequency needle probes have more recently been employed to elicit paresthesias in awake patients to map the pain generators and guide treatment. In this chapter, we provide a description of the development and basic mechanisms of peripheral nerve stimulation, as well as a more detailed description of the two most commonly employed forms of peripheral nerve stimulation: occipital nerve stimulation for occipital neuralgia, and subcutaneous peripheral nerve field stimulation to stimulate free nerve endings within the subcutaneous tissue when the pain is limited to a small, well-localized area. The closely related ideas of internal and external targeted subcutaneous stimulation are also discussed.
The article highlights the properties and applications of biopolymers such as chitin and chitosan. Traditional sources of chitosan obtaining and problems of their application are reviewed. Alternative, more perspective sources for chitosan obtaining are proposed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.