Facial Reanimation of the Eye Using Neurovascularised Flap of Platysma

Background: Dynamic reanimation is usually required to restore blink function in patients with chronic facial paralysis. In which case, platysma myocutaneous flap (PMF) is a good choice compared to gracilis flap. Platysma is a thin, pliable flap with matching skin colour to the eyelids. Despite this, it is underused. Aim: To investigate the neurovasculature of platysma in order to find a common “window” containing nerves and blood vessels supply which is present in every individual. This will aid the plastic surgeons to reconstruct the neurovasculature of the flap for grafting onto the eyelids. Methods: 3 fresh cadaver necks were dissected from 1 males and 2 females, aged 75-88 years old; (n=6 platysmas). 43 squared specimens (measuring 1.5cm x 1.5cm) surrounding any potential neurovascular structures were cut out, processed and analysed under high power microscope to confirm the presence of nerves and blood vessels. We also reviewed literature dated from 1999 to 2011. Results: From the literature reviewed, the authors concluded that PMF provided excellent functional and aesthetic outcome. In this study, we discovered a “window” flap (ranging from "2.5cm x 3cm‟ to "8cm x 10cm‟) bilaterally on each cadaver. This window is supplied by submental branch of facial artery, drained by facial vein, anterior and external jugular veins, and extensively innervated by cervical branch of facial nerve. Conclusion: We strongly advocate the use of PMF “window” by plastic surgeons in dynamic eyelids reanimation.

Conceptualization of Hand-TaPS to measure the subjective experience of dynamic hand orthoses in promoting functional recovery at home after stroke

BACKGROUND: Dynamic exoskeleton orthoses provide assistance needed to complete movements that would otherwise be impossible after stroke. Beyond the demonstration of their effectiveness, the subjective experience of dynamic orthoses also needs to be considered. OBJECTIVE: To support functional recovery after stroke through the development of Hand-TaPS (Task Practice after Stroke), an instrument to evaluate dynamic hand orthoses in home therapy. METHODS: Dynamic hand orthosis subject matter experts (N= 14), professionals and consumers, considered the items of PYTHEIA, a valid and reliable instrument merging well-tested, assistive technology (AT) assessment items with those tuned to the greater complexity of emerging technologies. Experts reflected on how each item aligned with their personal experience of dynamic orthosis use. Interpretative Phenomenological Analysis guided identification of themes. RESULTS: Four themes (5/20 items) appraised highly relevant for Hand-TaPS. The remaining eight themes (15/20 items) were deemed in need of modification. CONCLUSIONS: Dynamic hand orthoses constitute a special case of AT; the assistance they provide targets therapy, not ADLs. Our work to develop Hand-TaPS provides a clear example of the theoretical difference between rehabilitative and assistive technology and underscores the importance of consideration of how a device is used in its assessment.

The effect of hematocrit, fibrinogen concentration and temperature on the kinetics of clot formation of whole blood

BACKGROUND: Dynamic mechanical analysis of blood clots can be used to detect the coagulability of blood. OBJECTIVE: We investigated the kinetics of clot formation by changing several blood components, and we looked into the clot “signature” at its equilibrium state by using viscoelastic and dielectric protocols. METHODS: Oscillating shear rheometry, ROTEM, and a dielectro-rheological device was used. RESULTS: In fibrinogen- spiked samples we found the classical high clotting ability: shortened onset, faster rate of clotting, and higher plateau stiffness. Electron microscopy explained the gain of stiffness. Incorporated RBCs weakened the clots. Reduction of temperature during the clotting process supported the development of high moduli by providing more time for fiber assembly. But at low HCT, clot firmness could be increased by elevating the temperature from 32 to 37°C. In contrast, when the fibrinogen concentration was modified, acceleration of clotting via temperature always reduced clot stiffness, whatever the initial fibrinogen concentration. Electrical resistance increased continuously during clotting; loss tangent (D) (relaxation frequency 249 kHz) decreased when clots became denser: fewer dipoles contributed to the relaxation process. The relaxation peak (Dmax) shifted to lower frequencies at higher platelet count. CONCLUSION: Increasing temperature accelerates clot formation but weakens clots. Rheometry and ROTEM correlate well.