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Motion of venous valves in humans—a new discovery
Published in Dinker B. Rai, Mechanical Function of the Atrial Diastole, 2022
In summary, this chapter records a discovery that venous valves in human beings open and close during each cardiac cycle in a rhythmical fashion. The motion is present in all postures but becomes more prominent when the person is in the erect posture. This chapter does not address whether this motion is passive or active or its relationship to heart function. This finding raises many questions related to venous circulation. It may provide a new understanding of the forces related to the motion of blood in the venous system.
Wound Healing, Ulcers, and Scars
Published in Ayşe Serap Karadağ, Lawrence Charles Parish, Jordan V. Wang, Roxburgh's Common Skin Diseases, 2022
Saloni Shah, Christian Albornoz, Sherry Yang
Definition: Venous insufficiency is defined as an impediment to flow within the venous circulation, resulting in dilation of venules and increased pressure. This ultimately results in capillary leakage and extravasation into surrounding soft tissue. This most commonly affects lower leg veins.
Classification and clinical features
Published in Aparna Palit, Arun C. Inamadar, Systemic Sclerosis, 2019
Aparna Palit, Arun C. Inamadar
The most prominent vasculopathic manifestation in patients with SSc is Raynaud’s phenomenon (RP). This may occur during the early stage and often may be the presenting feature. Body parts with end-vasculature, like distal fingers and toes are the most common sites of involvement. The tip of the nose and helices of the ears may sometimes be affected. Sudden exposure to cold water and lower environmental temperatures precipitate the episodes of RP. The other important triggering factor for RP in these patients is emotional stress.3,4 The evolution of an episode of RP is through three phases of color changes (tri-color phenomenon).3,4Well-demarcated pallor (Figures 3.24 and 3.31) that may be painful (due to arterial vasospasm and ischemia)4Bluish/cyanotic hue (Figure 3.32), indicative of slow deoxygenated venous circulationErythema (reactive hyperemia after circulation is re-established)
Optociliary Shunt Vessels or Neovascularisation of the Optic Disc: Fluorescein Angiography Versus Optical Coherence Tomography Angiography
Published in Neuro-Ophthalmology, 2022
Ferdane Ataş, Ali Osman Saatci
In the present case, we observed OSVs in the right eye and NVD in the left eye as a consequence of bilateral CRVO. Distinguishing the OSVs from NVD is of paramount importance in order to select the appropriate treatment and estimate the prognosis. Singh et al. reported that OSVs are characterised by small calibre, sinusoidal vessels that can be best observed on RPC slabs of the optic disc OCTA.13 They also showed that OSVs are larger than RPCs and have a smaller calibre than the retinal veins. Moreover, they mentioned that NVD is a mesh of irregular new vessels that arise from the venous circulation and tend to penetrate the internal limiting membrane. In cross-sectional OCTA images, NVD appears on a plane rising above the retinal surface and shows abnormally present flow signal. In contrast to NVD, OSVs exhibit no abnormal signal and are not visible at the anterior surface of the optic disc on OCTA images.13
Cerebral venous sinus stenosis should not be neglected when cerebral artery stenosis is confirmed: a case report
Published in International Journal of Neuroscience, 2021
Zhongao Wang, Jiayue Ding, Jian Chen, Yuchuan Ding, Xunming Ji, Ran Meng
Cerebral venous sinus stenting can resolve IH, attenuate papilledema and remove tinnitus in patients with CVSS [2,20]. The decreased pressure gradient and the restored venous outflow may facilitate the cerebral spinal fluid absorption and normalize the cerebral blood circulation, all of which play an important role in symptomatic improvement [4,20,21]. In this patient, despite bilateral CVSS, the symptoms were rapidly relieved after deploying a stent at the right stenosis segment. That is, unilateral stent placement may be enough on relieving the symptoms of bilateral CVSS when no unilateral dominance was detected at bilateral transverse sinuses by DSA [22]. The improvement of symptoms immediately after venous patency indicated that cerebral venous circulation disturbance, caused by CVSS, was strongly associated with the existing symptoms. Fluent cerebral venous blood flow promotes the cerebral metabolites excretion, augments the cerebral arterial perfusion and increases the oxygen content in brain tissue [7,18]. Moreover, gadolinium contrast agent may be a good alternative in DSA examination, when the patient is allergic to iodic contrast agent.
Thrombosis in Covid-19 and non-Covid-19 pneumonia: role of platelets
Published in Platelets, 2021
Francesco Violi, Vittoria Cammisotto, Pasquale Pignatelli
While retrospective and prospective studies consistently demonstrated a close association between clotting activation and poor outcomes including thrombotic event and death in Covid-19, data regarding the impact of platelet activation on clinical outcomes are scarce. Barrett et al. [42] reported data on several markers of in vivo platelet activation in 100 patients affected by Covid-19, who experienced thrombosis or death in 34 cases; according with previous reports thrombotic events were almost equally distributed between arterial and venous circulation (eight VTE, five MI, one VTE and MI). Among the platelet biomarkers, soluble CD40L, P-selectin and serum TxB2 were independently associated to thrombosis or death. When considering thrombosis separately, only TxB2 was independently associated with thrombosis; the association between TxB2 and both clinical outcomes persisted also after excluding patients on aspirin treatment. Even if interesting, these data should be considered preliminary and warrant further analysis to elucidate the relationship between platelet activation and thrombosis in Covid-19 patients. Figure 1 synthetizes the above reported interactions between Covid-19 and platelets.