1. Thoracic Insufficiency Syndrome
Laura Stoll
November 2010

2. Normal thorax Spine + rib cage + sternum + diaphragm
Lung development depends on thoracic growth
Increase in T-spine height
Symmetrical enlargement of rib cage through rib growth
Correct orientation of ribs

3. Thoracic spine growth Birth-5 years: 1.4 cm/yr 6-10 years: 0.6 cm/yr
Marked loss of T-spine height = severe reduction in thoracic volume for lungs
Jarcho-Levin syndrome (spondylothoracic dysplasia)
Single, short, block vertebra (1/4th normal height)
High mortality due to respiratory complications
Campbell RM, et al 2007; Ramirez N, et al

4. Rib contribution Birth - 2 years: 2 years-10 years:
Ribs horizontal = growth of rib in length
Increase in diameter of rib cage = square-shaped thoracic cross-section
2 years-10 years:
Rib course downward = oval-shaped thoracic cross-section
10 years - skeletal maturity:
Ribs grow rapidly = final rectangular shaped thoracic cross-section

5. Rib cage contributes to volume increase by expanding anteriolaterally - “buckethandle” biomechanism
Diaphragm “piston” increases thoracic volume by downward excursion

6. Thoracic insufficiency syndrome
Inability of the thorax to support normal respiration or lung growth
Thoracic insufficiency syndrome does not equal respiratory insufficiency
Dx based on H&P, imaging studies, V-P lung scans, PFTs, labs
Campbell RM, et al 2003

7. Disorders of normal, stable thorax volume
Causes extrinsic restrictive lung disease
Scoliosis with absent or fused ribs
Scoliosis with windswept deformity
Jarcho Levine syndrome
Jeune syndrome
Jarcho Levin syndrome (multiple vertebral and rib fusion anomalies)
Jeune syndrome (asphyxiating thoracic dysplasia)

8. AP and lateral chest radiograph of patient with Jarcho-Levin syndrome at 2 months of age shows crab-like chest appearance and limited bilateral lung aeration and multiple rib and vertebral body abnormalities.
Jarcho-Levin Syndrome: symmetric "crab-like" chest that is caused by the ribs crowding and fusing at their origin at the spine and fanning out along their lengths. Can have various numbers and shapes of ribs as well as vertebral segmentation defects consisting of fusion or absence of vertebrae, hemivertebrae, and butterfly vertebrae. Mild scoliosis, secondary to the multiple hemivertebrae, is present in most patients.

9. Disorders of thorax’s ability to change volume
CDH - decreased contraction of diaphragm
Unilateral hemidiaphragm paralysis
Anomalous insertion of the diaphragm in congenital scoliosis and rib anomalies
Secondary thoracic insufficiency syndrome - torso collapsed on pelvis
Campbell RM, et al 2004

10. This is a classification for thoracic volume-depletion deformities
Developed by Robert Campbell on the basis of radiographs and CT studies of the thorax.
Enables the surgeon to the best surgical approach.
Type I and II: Asymmetric deformities, with unilateral volume-depletion deformities that require unilateral surgical expansion to restore thoracic volume and symmetry in the coronal plan.
Type III deformities have a global thoracic volume deficit which may be due to either a symmetrical longitudinal constriction such as that in Jarcho-Levin syndrome or a symmetrical transverse-plane constriction such as that in Jeune asphyxiating thoracic dystrophy. Require bilateral staged surgical correction to either lengthen or laterally expand the symmetrically constricted thorax.
Jarcho Levin syndrome (multiple vertebral and rib fusion anomalies, foreshortened thorax)
Jeune syndrome (asphyxiating thoracic dysplasia)
Campbell RM, et al 2007

11. Standard scoliosis:
Thorax usually spacious, no rib cage deformities, near normal vital capacity
Characterized by degree of curve on AP radiographs
Tx: bracing or definitive spinal fusion

12. Exotic scoliosis Early onset
Thorax distorted by spinal lordosis and curve rotation
Often associated with rib-cage deformities: absent or fused ribs
Volume depletion deformity and thoracic growth inhibition = adverse effects on lung growth

13. Can’t do conventional treatments (fusion):
Bone stock may be insufficient
Patient too small for standard implants for fusion
Lung function may be too poor
Will not address the 3D thoracic deformity
Loss of growth of T-spine from early fusion would impact thoracic volume

14. VEPTR Vertical expandable prosthetic titanium rib
Dr. Robert Campbell and Dr. Melvin Smith of Christus Santa Rosa Children’s Hospital in San Antonio, TX
Received FDA approval in August 2004

15. Surgical Indications Rib fusion and progressive scoliosis
Hypoplastic thorax syndrome
Jeune’s syndrome
Achondroplasia
Jarcho-Levin syndrome
VACTERL syndrome
Flail chest syndrome
Rib agenesis
Acquired causes

16. Type I: Absent ribs and scoliosis
Stabilization expansion thoracoplasty
Stabilizes the flail chest-wall segment
Laterally expands and lengthens the collapsed hemithorax section
2-3 VEPTR devices used

17. Fig. 5-A A four-year-old girl with type-I volume-depletion deformity from rib absence and scoliosis. Fig. 5-B The VEPTR stabilization expansion thoracoplasty lengthened and widened the constricted hemithorax and thereby increased the space available for lung to 90%, corrected the exotic scoliosis indirectly without growth inhibition, restored truncal balance, and corrected pelvic obliquity.
Campbell RM, et al 2007

18. Type II - fused ribs and scoliosis
Opening wedge thoracostomy
Fused hemithorax is osteotomized transversely, lengthened until the thorax is equilibrated
Those under 2 years old with no history spine surgery do best
Campbell RM, et al 2007

19. Fig. 6-A 4yo boy with a type-II volume-depletion deformity resulting from fused ribs and scoliosis. The curve was 102ｰ, the space available for lung was 21% of normal, and the respiratory rate was elevated. Fig. 6-B VEPTR opening-wedge thoracostomy lengthened the constricted hemithorax by 200%, increasing the space available for lung to 64% of normal, reducing the curve to 45ｰ, and improving truncal balance and head tilt.
Campbell RM, et al 2007

20. Type IIIa - Jarcho-Levin Syndrome
Staged bilateral opening-wedge thoracostomies
Rib-to-rib VEPTR devices
Lengthen sequentially constricted hemithorax while correcting any associated scoliosis
Campbell RM, et al 2007

21. Fig. 7-A A 3yo boy with a type-IIIa volume-depletion deformity from Jarcho-Levin syndrome. Fig. 7-B At the six-year follow-up, after staged bilateral VEPTR opening thoracostomies, growth of the thoracic spine and the thorax has occurred.
Campbell RM, et al 2007

22. Type IIIb - Jeune syndrome or infantile scoliosis with windswept deformity
Circumferential thoracic constriction
Staged bilateral dynamic segmental curved VEPTR
In windswept deformity scoliosis, concave chest is lengthened with opening-wedge thoracostomy, lengthening of hemithorax, stabilization with unilateral rib to spine or rib to pelvis VEPTR
Campbell RM, et al 2007

23. Fig. 8-A An infant with a type-IIIb volume-depletion deformity from Jeune syndrome. Fig. 8-B After staged bilateral dynamic segmental posterolateral expansion thoracoplasties, improvement in the lateral width of the thorax is seen.
Large segment of chest wall containing six to seven ribs is mobilized by rib osteotomies anteriorly near the costochondral junction and by osteotomies posteriorly just lateral to the transverse processes. Iatrogenic flail chest segment is acutely distracted outward, increasing thoracic volume and is attached by titanium slings to the VEPTR The diastasis betweent he osteomtoized ribs fills in with new bone and the new thoracic space fills in witth pleural effusion, but lung lucency is seen at about 6 months extending out. The second side is treated 3-6 months later. Periodic expansion continues to drive chest wall outward for continued gains in volume.
Windswept: lysis of intercostal m.m. at the apex of the hemithorax constriction

24. VEPTR complications
Prone to complications due to repetitive nature of maintenance surgeries
Wound infection - 3.3% per procedure
Skin slough
Scarring
Migration of fixation migrations/yr/pt
Device breakage
Brachial plexus injuries
Campbell RM, et al 2007

25. Outcomes Improvement of percentile weight
Decreased in ventilator dependence, increase in thoracic volume
+/- increase in lung volume (and decrease in FVC) - benefit may lie more in stabilizing thorax and improving respiratory mechanics measured in other ways
10/21 patients had increased activity levels postoperatively
Skaggs, et al; Campbell RM, et al 2007; Yazici, et al; Mayer, et al; Waldhausen, et al

26. Further defining thoracic insufficiency syndrome
VEPTR new device. Long term follow-up studies still needed

27. References Campbell RM, et al. JBJS Am. 2003;85:399
Campbell RM, et al. JBJS Am. 2004;86Suppl1:51
Campbell RM, et al. JBJS Am. 2007;89-A:108
Mayer, et al. J Pediatr Orthop. 2009;29:35
Rameriz N, et al. JBJS Am. 2007;89:2663
Skaggs, et al. Spine. 2009;34:2530
Waldhausen JHT, et al. J Pediatr Surg. 2007;42:76
Yazici, et al. Spine. 2009;34:1800