Study procedures
1. Patient Identification \& Enrollment Patients meeting the inclusion criteria will be invited to enroll in the study as described above.
2. Serial clinical observation
Patients will be followed over time for progression of thoracic insufficiency indicators:
* Worsening respiratory status oFrequent respiratory infections oElevated resting respiratory rate oEase of fatigability oHypoxia and hypercapnia oMarionette sign (trunk and shoulder elevation and depression with respiration)
* Primary diaphragmatic breathing (loss of chest wall mobility)
* Progressive scoliosis
* Failure of thoracic dimensions to increase with growth
Patients with progressive thoracic insufficiency will be offered surgical intervention with expansion thoracoplasty utilizing the VEPTR device.
Studies which are standard of care for TIS will be utilized to assess patients. Routine standard of care studies will be obtained:
1. MRI of the spine will be obtained at presentation.
2. Chest CT scan (every 2 years, or less frequently if clinically indicated)
3. AP/Lat spine xrays (to include the chest wall)
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1. Will be obtained every 6 months - 12 months
2. If a patient has a VEPTR implantation, the typical schedule of radiographs would include immediate postoperative xrays (the day of surgery and/or early postoperative period) and at 6 weeks, 12 weeks, and 6 months postoperative.
3. VEPTR lengthening will typically take place every 6 months after the initial VEPTR implantation.
i.Xrays will be obtained every 6 months in association with the VEPTR lengthening.
ii.Once VEPTR lengthening is no longer clinically indicated, the patients will be followed with xrays every 6-24 months until skeletal maturity.
d.Pulmonary function tests (spirometry) will be obtained every 6-12 months in children who are old enough to participate (typically \> age 4 years).
e.Arterial and/or capillary blood gases
a.Blood gases will be obtained every 6-12 months if clinically indicated and perioperatively for VEPTR implantation / lengthening.
f.Routine vital signs including resting pulse oximetry (SaO2)
a.Will be assessed at clinic visits and perioperatively g.All of the above mentioned studies will be obtained more or less frequently as clinically indicated.
3. Expansion thoracoplasty with VEPTR implantation and subsequent lengthening with the VEPTR will be performed following informed consent. The surgical technique will be as described by Campbell.3 The VEPTR device will be lengthened at 6 to 12 month intervals until thoracic and spinal deformities have stabilized radiographically.
