Adipose-derived stem cell procedure restores skull defects after brain surgery

Jun 2 2011

Stem cells derived from abdominal fat—used along with a synthetic bone grafting material—are a potentially valuable new approach to repairing skull defects after brain surgery, according to a study in the June issue of Neurosurgery, official journal of the Congress of Neurological Surgeons. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

Preliminary results suggest that adipose-derived stem cells (ASCs)—easily developed from a small sample of abdominal fat—are a useful material to fill large skull defects. The study was performed by Dr. Tumo Thesleff and colleagues of Tampere University Hospital, Finland.

Preliminary Study Shows Good Results with ASCs Used to Repair Skull Defects
The researchers used the ASC technique to restore skull defects in four patients, average age 64 years. All patients had persistent skull defects—averaging about 3 by 2½ inches in size—resulting from complications after surgery. Stem cells were prepared from a small sample of fat obtained from the patient's abdomen.

These fat-derived stem cells are an intriguing new source of stem cells for research and treatment purposes. Unlike bone marrow-derived stem cells, ASCs can be obtained in large numbers and easily expanded. Similar to bone marrow stem cells, ASCs can be induced to develop (differentiate) into many different kinds of cells—including bone-forming (osteogenic) cells.

After developing the stem cells, Dr. Thesleff and colleagues combined them with a synthetic bone grafting material (called betaTCP) to fill the skull defects in the four patients. The results were assessed by computed tomography (CT) scans performed the week after surgery and at three months' and one year's follow-up.

The ASC procedure provided good results in restoring the skull defects with firm new bone. On the follow-up CT scans, the new bone filled in gradually, reaching the density of the neighboring bone within several months.

Patients undergoing brain surgery for cancer or other reasons are sometimes left with skull defects, especially after infections or other complications. Reconstruction of these defects can pose a challenging problem for neurosurgeons and plastic surgeons. Current options for repair—including the patient's own bone or synthetic materials—have important limitations.

The new study suggests that ASCs are a promising alternative for repair of these persistent skull defects. The cells are easily obtained and developed into bone-forming cells. In combination with synthetic bone-graft material, they can be used to create a "custom-made" implant for the patient. "Further studies and development are needed to turn this method into a reproducible and reliable treatment regimen in cranial bone reconstruction," Dr. Thesleff and colleagues conclude.