Tag: implant

Categories : Implants and Prostheses Neurodegenerative DiseasesTags :

Implant Helps Patient with Neurodegenerative Disease to Walk Again

On By ModernMedia
Patient takes steps with the help of an assistant. Credit: Jmmy Ravier & NeuroRestore

A woman bedridden for over a year due to a debilitating neurodegenerative disease was able to get up and walk again, thanks to an innovative electrical stimulation system which was able to raise her blood pressure on standing and prevent her fainting. The system was developed by a team headed by Professors Jocelyne Bloch and Grégoire Courtine, and was detailed in The New England Journal of Medicine.

Their system includes electronics implanted directly on the spinal cord to reactivate the neurons that regulate blood pressure, thereby preventing the patient from losing consciousness every time she’s in an upright position. This type of implant was already in use for the treatment of low blood pressure in tetraplegic patients.

The female patient in the study suffers from multiple system atrophy-parkinsonian type (MSA-P), a neurodegenerative disease that afflicts several parts of the nervous system, including the sympathetic nervous system. 

MSA-P leads to the loss of sympathetic neurons regulating blood pressure, which results in orthostatic hypotension, a dramatic blood pressure drop when patients are in an upright position, which in some cases results in fainting. This increases fall risks, limits mobility, and can eventually shorten life expectancy. Having to remain in a reclined position to avoid passing out severely impacts patients’ quality of life.

The implant consists of a set of electrodes connected to an electrical-impulse generator typically used to treat chronic pain. After implanting their device directly on the patient’s spinal cord, the researchers found an improvement in the body’s capacity to regulate blood pressure, enabling the patient to remain conscious for longer periods in an upright position and to begin physical therapy to walk again. After being bedridden for 18 months, the patient is now able to walk as far as 250 metres.

For Jocelyne Bloch, this marks an important step toward the treatment of degenerative diseases: “We’ve already seen how this type of therapy can be applied to patients with a spinal-cord injury. But now, we can explore applications in treating deficiencies resulting from neurodegeneration. This is the first time we’ve been able to improve blood-pressure regulation in people suffering from MSA.”

Grégoire Courtine added that “this technology was initially intended for pain relief, not for this kind of application. Going forward, we and our company Onward Medical plan to develop a system targeted specifically to orthostatic hypotension that can help people around the world struggling with this disorder.”

Source: Ecole Polytechnique Federale de Lausanne

Categories : Implants and Prostheses PaediatricsTags :

Lab-made Heart Valves That Can Grow With The Recipient

On By ModernMedia

In a new study, lab-made heart valves were shown to grow along with their recipient when implanted into lambs for a year, making a new alternative possible for thousands of paediatric patients who need replacement heart valves. 

Researchers from the University of Minnesota Twin Cities’ College of Science and Engineering and the Medical School published the results in Science Translational Medicine. The production procedure for the valves has also been patented and licensed to the University of Minnesota startup company Vascudyne, Inc.

Compared to currently used animal-derived valves, these new valves also showed reduced calcification and improved blood flow when tested in the same growing lamb model. Current solutions for children involve prosthetic valves, but these calcify over time and cannot grow with the patient. This requires up to five open-heart surgeries to replace them as the children grow towards adulthood, involving considerable risk and expense, as well as demanding lifelong anticoagulation therapy.

“This is a huge step forward in paediatric heart research,” commented senior researcher Robert Tranquillo, a University of Minnesota professor in the Departments of Biomedical Engineering and the Department of Chemical Engineering and Materials Science. “This is the first demonstration that a valve implanted into a large animal model, in our case a lamb, can grow with the animal into adulthood. We have a way to go yet, but this puts us much farther down the path to future clinical trials in children. We are excited and optimistic about the possibility of this actually becoming a reality in years to come.”

Using a combination of tissue engineering and regenerative medicine, they were able to grow the heart valves. Implementing a tissue engineering technique they had previously developed, they grew tube-like structures out of skin cells. This involved combining the skin cells in fibrin, and providing nutrients in a bioreactor. After washing the skin cells out with detergent, the researchers were left with a collageneous matrix which would not provoke an immune response when implanted. They then sewed and trimmed three of these tubes together to make a 19mm diameter heart valve-like structure.

“After these initial steps, it looked like a heart valve, but the question then became if it could work like a heart valve and if it could grow,” Tranquillo said. “Our findings confirmed both.”

The valves grew from 19mm to 25mm over a year, and showed little of the calcification or clotting associated with prosthetic valves, while performing better than animal-derived valves.”We knew from previous studies that the engineered tubes have the capacity to regenerate and grow in a growing lamb model, but the biggest challenge was how to maintain leaflet function in a growing valved conduit that goes through 40 million cycles in a year,” said lead researcher Zeeshan Syedain, a University of Minnesota senior research associate in Tranquillo’s lab. “When we saw how well the valves functioned for an entire year from young lamb to adult sheep, it was very exciting.”

The next steps are to implant the valve into the right ventricle of the heart to see how it performs, and apply for FDA approval to proceed to human trials. 

Source: Medical Xpress

Journal information: Zeeshan H. Syedain et al, Pediatric tri-tube valved conduits made from fibroblast-produced extracellular matrix evaluated over 52 weeks in growing lambs, Science Translational Medicine (2021). DOI: 10.1126/scitranslmed.abb7225

Categories : Implants and ProsthesesTags :

New Type of Corneal Implant Fuses into the Eye

On By ModernMedia

A new type of artificial cornea has been successfully implanted into an elderly patient, who demonstrated recovered sight the day after his surgery.

When the cornea is damaged by disease or injury, blindness can result, necessitating a cornea transplant. Artificial corneas are a much sought-after technology, as the normal treatment for a damaged cornea is to seek a transplanted replacement. However, for every 70 corneas sought, there is only a single donor cornea. CorNeat Vision is set to offer the first commercially available synthetic cornea implant, the KPro.

The new cornea has a clear centre section, surrounded by a white skirt consisting of electrospun nanofibres. Electrospun nanofibres have already found application in many medical applications, such as a new kind of translucent burn dressing. This skirt’s nanofibre material allows fibroblasts and collagen to infiltrate its structure, allowing full integration within a few weeks of surgery. This biomimetic technology results in faster healing times, the ability to use fully synthetic implants and is fully scalable as it does not rely on any harvested tissue.

The implantation procedure involves removing the epithelium covering the cornea, marking the location of where the artificial cornea implant should go, removing the cornea and then suturing its replacement into position.

Only a day after his surgery, the first recipient of this new artificial cornea was able to make out the faces of his relatives and read numbers off of a chart.

Source: Medical Xpress