The effect of the calibre and length of needle on the stability of sclerosing foam.

OBJECTIVES: Little is known how calibre and length of needles affect the stability of sclerosing foam. METHODS: Foams were made of 0.5%, 1%, 2% and 3% polidocanol, and 0.2%, 0.5%, 1% and 3% sodium tetradecyl sulfate (STS), which were mixed with air in the proportion of 4:1. These foams were ejected through needles with the length of: 4 mm, 6 mm and 13 mm, and diameter of: 0.26 mm, 0.3 mm and 0.4 mm. RESULTS: Foams made of more concentrated polidocanol were more stable. Regarding STS an opposite relationship was revealed. Foams made of polidocanol were more stable if ejected through a longer needle, while the length of needle did not significantly affect stability of STS foams. Foams ejected through 0.26 mm diameter needles were very unstable. In the case of 0.5% polidocanol, 0.3x6mm needle provided atypically stable foam. CONCLUSION: In order to inject maximally stable foam, calibre and length of needle should be taken into account.

Potential Involvement of Impaired Venous Outflow from the Brain in Neurodegeneration: Lessons Learned from the Research on Chronic Cerebrospinal Venous Insufficiency.

About 10 years ago, the so-called chronic cerebrospinal venous insufficiency syndrome was discovered. This clinical entity, which is associated with extracranial venous abnormalities that impair venous outflow from the brain, was initially found exclusively in multiple sclerosis patients. Currently, we know that such venous lesions can also be revealed in other neurological pathologies, including Alzheimer's and Parkinson's diseases. Although direct causative role of chronic cerebrospinal venous insufficiency in these neurological diseases still remains elusive, in this paper, we suggest that perhaps an abnormal venous drainage of the brain affects functioning of the glymphatic system, which in turn results in the accumulation of pathological proteins in the cerebral tissue (such as ß-synuclein, ß-amyloid and α-synuclein) and triggers the venous outflow from the cranial cavity and circulation of the cerebrospinal fluid in the settings of neurodegenerative disease.