VEPTR Treating three-dimensional thoracic deformity of early onset scoliosis

The Synthes Spine Vertical Expandable Prosthetic Titanium Rib (VEPTR) allows new growth sparing surgical procedures for treatment of spine deformity in early childhood. The prime FDA indication for its use is the presence of thoracic insufficiency syndrome [1], which is the inability of the thorax to support normal respiration or lung growth. This syndrome is most often due to three-dimensional thorax deformity. A major shift in paradigm has occurred: spine deformity can no longer be considered an isolated deformity, but rather should be considered a component of the total thoracic deformity that adversely impacts thoracic volume, function, and growth. VEPTR is not a new “growing rod”; it is an instrumentation that stabilizes volume enhancing thoracic reconstructions. Specific VEPTR expansion thoracoplasties can address the different anatomic volume depletion deformities of the thorax [2] (Table I), indirectly correcting scoliosis without fusion, allowing the thoracic spine to grow and contribute to thoracic volume with probable benefit to the growth of the underlying lungs. Early spine fusion, a growth inhibition procedure, does not seem to address thoracic insufficiency syndrome (TIS) with recent reports [3, 4, 5] emphasizing that early spine fusion is associated with decreased vital capacity by maturity. VEPTR is a “buy time” procedure, correcting the thoracic deformity early in life, so rib cage and spinal growth can nurture lung development with definitive spine fusion postponed until adolescence when thoracic volume is optimal. At this time, unfortunately little is known about the normal interrelationship between spine, rib cage and lung growth, or how spine deformity distorts the rib cage with loss of thoracic volume for lung growth, or how biomechanically the spine deformity disables the thoracic ability to expand the lungs through rib cage motion. While much remains to be learned, some basic knowledge exists.