The Vertical Expandable Prosthetic Titanium Rib
The vertical expandable prosthetic titanium rib or VEPTR, was invented by a surgeon in San Antonio, Texas, named Bob Campbell, in the early 1990’s. Fourteen years later, in 2004 the device was approved by the Food and Drug Administration (FDA) for the treatment of Thoracic Insufficiency Syndrome under a special category called HDE.
Thoracic Insufficency Syndrome is a new diagnosis. It didn’t exist ten years ago, and it wasn’t until March of 2003 when an article was published by Dr. Campbell in the Journal of Bone and Joint surgery (www.jbjs.org) that the concept recieved the widespread recognition that it deserves. Currently, thoracic insufficiency syndrome is defined as a failure of the thorax to support normal respiration. Clinically, this means that the chest is either too small, or doesn’t work right, so the patient can’t get enough oxygen to live a normal life.
This syndrome is thought to occur as a consequence of severe spinal deformities that occur in very young children, or as a consequence of spinal fusion surgery at a young age.
These two pictures are the x-rays of the chest of a young child with progressive scoliosis of the spine. The treatment options for a curve of this size, at this age, are limited, but include things like bracing, growing rods, early fusion, or treatment with the VEPTR device. Each of these options has it advantages and disadvantages, and the decision about which treatment strategy is most appropriate is currently a great source of debate amongst some of the most senior and experienced spine surgeons in the world.
In this case, this child was treated with an opening wedge thoracostomy on the convex side of the curve and two titanium ribs were placed. An opening wedge thoracostomy means that the side of the chest was surgically opened, and a space between the ribs was created, and then held open by the smaller of the two devices in the picture below. This part of the procedure is designed to make more space for the lung, in the hopes that it will expand to a larger size. A second rib has been placed from near the top of the chest to near the bottom of the spine in order to partially correct the scoliosis.
Each of these ribs will be lengthened, usually every six months, in a short surgical procedure through a small incision, in order to keep up with the child’s growth. It is not known for certain if all children who are treated with a rib will also require a full spine fusion when they are old enough, but it seems likely that most will.
The results of this form of treatment are the subject of many ongoing clinical trials. There is a study group that consists of surgeons, pulmonologists, clinical researchers, and engineers from the Children’s Hospitals in San Antonio, Boston, Philadelphia, Los Angeles, Salt Lake City, Pittsburgh, Philadelphia, and Seattle. This group meets three of four times a year and investigates the results of this type of surgery and presents the results to national and international meetings of pediatric orthopedic surgeons and spine surgeons for further dicussion.
I frequently get requests for workable copies of the pediatric lung volume charts. These data were published in the following paper: Gollogly S, Smith JT, White SK, Firth S, White K. The volume of lung parenchyma as a function of age: a review of 1050 normal CT scans of the chest with three-dimensional volumetric reconstruction of the pulmonary system. Spine. 2004 Sep 15;29(18):2061-6.
The charts can be downloaded in PDF format using the following links, and they have been subdivided into two different age groups: 0-18 years of age, and 0-8 years of age. The 0-8 year charts are designed to improve the resolution of these data in determining relative lung volume during the more critical phases of lung growth and surgical decision making.
- Male lung volume and density
- Female lung volume and density
- Total lung volume derived by analysis of 3D CT scans
Unpublished data on changes in lung density during growth are also available from birth to 18 years of age as derived from a smaller cohort of 334 children that had non-contrast CT scans of the chest. These data are currently reported for total lung volume and density only, but charts for right versus left lung densities are in the works.
Management of pediatric fractures
Surgical approaches for difficult deformities of the spine