Jan 30 2011
At KK Women's and Children's Hospital (KKH), a five-year old girl with severe curvature of the spine was among the first in Southeast Asia to have a "titanium rib" implant. Also known as the Vertical Expandable Prosthetic Titanium Rib (VEPTR), the adjustable titanium rib is designed to treat Thoracic Insufficiency Syndrome in skeletally immature patients. Thoracic Insufficiency Syndrome refers to the chest's inability to support normal growth of the lungs or spine.
Made of titanium, the rod is placed vertically between the ribs to keep the chest wall expanded. Curved to fit the back of the chest and spine, the rod helps the spine to become straighter, and allows the lungs to grow and fill with enough air to breathe. The device can be made longer as the child grows.
The device came to mind immediately for Dr Kevin Lim, Senior Consultant from KKH's Department of Orthopaedic Surgery, when he saw five-year old Alice Tan, who had been diagnosed with congenital scoliosis at birth.
By the time Alice turned two, she was struggling to walk and stand properly and would run out of breath very easily. Shares her mother, "Her body was bent badly by then. Fortunately, a friend recommended that I take her to KKH since it was known for its high level of medical expertise."
Alice made the trip from her home town in Kuching, Sarawak to Singapore in November 2007. Recalls Dr Lim, "There was clearly a deformity in her spine but only after we took some X-rays did we realise the extent of her curvature. It was distinctively S-shaped in nature and possibly the worst case of congenital scoliosis I'd seen in a long time."
Although Alice had some ribs that were normal on one side, most of her ribs on the opposite side were fused together. They were unlikely to grow in unison with the ribs on the 'good' side and this was expected to worsen her spinal curvature over time. Moreover, there were a few 'half-bones', a term used to describe bones that had not fully developed. But there was yet another, more pressing concern.
Dr Lim noted, "A curved spine alone is not life threatening, but in Alice's case, it was encroaching into the chest cavity. This can cause a lung problem where lung capacity becomes restricted. It's potentially fatal. Immediately, I was thinking of a new treatment that would be ideal for her."
Although the VEPTR was not available at that time, Dr Lim put Alice on the waiting list, ready to call her in once it arrived.
"We could have done another surgical procedure using a different implant, but that would only address problems with her spine and not her shrinking chest cavity. It was the second best option but a very distant one. So we agreed to wait," discloses Dr Lim.
When the titanium rib became available to KKH in the first week of August 2010, Alice joined two other children - a 14 month old girl and a two-year old boy - as the first ones in Southeast Asia to have the VEPTR device implanted.
During the four-hour procedure for Alice, several separations were made between the fused ribs to spread them apart and make the chest larger - referred to as an expansion thoracostomy. The straightening was achieved by attaching two rods: one to healthy ribs above and below the curve (rib-to-rib construct), and another to the healthy ribs above and to the spine below the curve (rib-to-spine construct). One other patient had a single rib-to-rib construct, while the last one required a rib-to-pelvis construct on each side.
The goal of the VEPTR is to make one (or both) sides of the chest larger, longer or more normal in shape so as to provide more room for the lungs to expand or grow. A larger or straighter chest can also help some abnormal spines stay as straight as possible while allowing for spinal growth.
Alice's one week hospital stay was without incident but according to Dr Lim, she will have to return every six to nine months to lengthen the device so as to accommodate her growing body. This will continue until she is around 12 years of age.
Dr Lim explains, "We want her torso to grow out as much as possible before we remove the device and do a final spinal fusion surgery which will join the vertebrae. It's important not to fuse a spine in a very young child."
Alice's mother elates, "Her head and body are straighter and not tilting to one side so much. I'm so happy that she can now do all the things a child her age likes to do."