Tissue-Engineered Blood Vessels Perform Well in a Study

Using patients’ own skin cells, scientists were able to grow tissue-engineered blood vessels in vitro, then implanted them in renal patients as AV fistulas. The engineered blood vessels performed well in a study of six patients over a 3 month period, scientists are reporting in the latest issue of New England Journal of Medicine. The group of scientists are from Cytographt Tissue Engineering of Novato, California, that developed the technique, and worked with doctors in Argentina to test the technology.
Here’s how the company describes its process:

A material that will approach the efficacy of native vein has been widely sought.1 Using autologous cells and a technique termed sheet-based tissue engineering, we were able to produce autologous tissue-engineered blood vessels with physiologic mechanical properties.2 No synthetic or exogenous materials were used; instead, the vessels were created with the use of autologous fibroblasts and endothelial cells harvested from a small biopsy specimen of skin and superficial vein. Here we report on the preliminary use of these tissue-engineered blood vessels in an adult arterial model.
Ten patients receiving hemodialysis whose arteriovenous shunts were failing were enrolled in this study. The subjects had typical risk factors for end-stage renal disease, including previously failed dialysis-access grafts, diabetes, controlled hypertension, and obesity. Patients ranged in age from 29 to 89 years (mean [±SD], 68±17). Vessel patency was evaluated by means of Doppler and angiographic imaging. Mechanically viable vessels were created with autologous cells for each patient. The average burst pressure among 54 vessels was 3340±849 mm Hg, which compares favorably with native veins.3
The primary objective of this study was to demonstrate that a tissue-engineered blood vessel produced in vitro could withstand the challenges of arterial pressure produced by an arteriovenous fistula for at least 3 months. After this observation period, grafts were punctured for hemodialysis access. To date, the first six patients have had vessels implanted and have been followed for up to 13 months.

Image caption: Image 1 – The Tissue-Engineered Blood Vessel Preoperative. Image 2 – At 3 Months after Implantation (Computed Tomographic Angiography)
Article abstract at the NEJM: Tissue-Engineered Blood Vessel for Adult Arterial Revascularization (N Engl J Med 357;14)…
Cytographt’s technology page…
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