Evaluation of surgical techniques for neuronal cell transplantation used in patients with stroke

Transplantation of cultured neuronal cells was performed in two human clinical trials after safety and efficacy was demonstrated in animal models of stroke. The studies tested the utility of human neuronal cellular transplantation into and around the small stroke volume. We developed a stereotactic surgical technique for cell delivery and evaluated that method in 26 patients with basal ganglia region motor stroke. Human neuronal cells (hNT cells; LBS neurons) were delivered frozen then thawed and formulated on the morning of surgery. Patients in a first trial received 2 or 6 million cells in three or nine implants, and in a second trial, 5 or 10 million in 25 implants. A novel cell delivery cannula was designed, manufactured, tested, and used in surgery. Immediate postoperative CT scans and later serial MR scans were used to evaluate the surgical site. Tests on the cell implantation cannula showed that the cells were not damaged and remained viable after injection. All patients underwent uncomplicated surgeries. Cells could be implanted within a 2-h period, maintaining viability of the preparation. Serial evaluations (maximum 5 years) showed no cell-related adverse serologic or imaging-defined effects. One patient had burr hole drainage of an asymptomatic chronic subdural hematoma. Human neuronal cells can be produced in culture and implanted stereotactically into the brains of patients with stroke. Surgical cell delivery did not lead to new neurological deficits, and imaging studies showed no adverse effects. The cannula used allowed precise injection of the clinical cell dose within a time period that maintained cell viability.