Thoracic insufficiency syndrome (TIS) is the inability of the thorax to support normal respiration or lung growth.  It results from serious defects affecting the ribs or chest wall such as severe scoliosis, rib fusion (which may accompany scoliosis), and various hypoplastic thorax syndromes such as Jeune’s syndrome and Jarcho-Levin syndrome. Spine, chest, and lung growth are interdependent. While the coexistence of chest wall and spinal deformity is well documented, their effect on lung growth is not completely understood.

 

Progressive thoracic insufficiency syndrome includes respiratory insufficiency, loss of chest wall mobility, worsening three-dimensional thoracic deformity, and/or worsening pulmonary function tests. As a child grows, progressive thoracic deformity and rotation toward the concave side occurs with worsening respiratory compromise. This progression is often accompanied by a need for supplemental oxygen and can require mechanical ventilation. While spinal fusion is one approach to treatment, it may not be successful and also may limit growth (lengthening) of the spine.

 

The vertical expandable prosthetic titanium rib (VEPTR, Synthes Spine Co.) is a curved rod placed vertically in the chest that helps to shape the thoracic cavity. It is positioned either between ribs or between the ribs and either the spine or pelvis. VEPTR may be described as “rib based” growth-sparing instrumentation, which is compared with “spine based” growing rods for Cobb angle correction. The device is designed to be expanded every 4 to 6 months as growth occurs and also to be replaced if necessary. Some patients require multiple devices.

 

 

 

 

Given the complexity of these procedures and patients, implantation of this device should be performed in specialized centers. Preoperative evaluation requires input from a pediatric orthopedist, pulmonologist, and thoracic surgeon. In addition, preoperative evaluation of nutritional, cardiac, and pulmonary function (when possible) is required.

 

There is no specific CPT code for this procedure. The procedure would most likely be reported with the unlisted code 22899.

 

 

 

 

 

 

 

 

Use of the vertical expandable prosthetic titanium rib meets primary coverage criteria for the treatment of progressive thoracic insufficiency syndrome due to rib and/or chest wall defects in infants/children between 6 months of age and skeletal maturity.  

 

For contracts without primary coverage criteria language, use of the vertical expandable prosthetic titanium rib is considered medically necessary for the treatment of progressive thoracic insufficiency syndrome due to rib and/or chest wall defects in infants/children between 6 months of age and skeletal maturity.  

 

Skeletal maturity occurs at about age 14 for girls and age 16 for boys.

Information from the FDA Web site reports results of an initial feasibility study involving 33 patients and a subsequent prospective study of 224 patients (214 with baseline data) at 7 study sites.  Of these patients, 94 had rib fusion, 93 had hypoplastic thoracic syndrome, 46 had progressive scoliosis, and 14 had flail chest as a cause of their thoracic insufficiency syndrome (TIS). Three- and 5-year follow-up rates for the multicenter study were approximately 95%. Of the 247 patients enrolled in either study, 12 patients died (4.8%) and 2 withdrew. None of the deaths was determined by investigators to be device related. Since standard pulmonary function testing was not possible for most of this population, an assisted ventilatory rating (AVR) was used to assess impact on respiratory status. The AVR ranged from 0 for unassisted breathing on room air to 4 for full-time ventilatory support. In the multicenter prospective study, the AVR outcome improved or stabilized for 93% of the patients. Data were not reported for the number of patients who were no longer ventilator dependent.

 

Several studies using this device have also been reported in the literature. One study is from Campbell, the developer of the device, (2004) and others who report its use in specialized pediatric centers (Emans, 2005; Motoyama, 2006).

 

Campbell and colleagues reported on 27 patients who had surgery for TIS and for whom at least 2 years of follow-up data were available; this series was based on 41 patients treated between 1990 and the acceptance of the paper. (2004)  Entry criteria for this study were acceptance by pediatric general surgeon, pediatric pulmonologist, and pediatric orthopedist; age 6 months to skeletal maturity; progressive thoracic insufficiency syndrome; more than 10% reduction in height of the concave hemithorax; and 3 or more anomalous vertebrae, with 3 or more fused ribs at the apex of the deformity. Patients were followed up for an average of 3.2 (2–12) years. Prior to surgery, the mean annual rate of progression was 15 degrees per year (range 2–50). Following surgery the Cobb angle (of scoliosis) improved from 74 degrees to a final value of 49 degrees. Spine growth was at the rate of 0.8 cm per year. (Normal spinal growth is 0.6 cm/year for ages 5–10 years.) The final forced vital capacity (FVC) was 49% of predicted value in the 19 children who could complete pulmonary function tests (PFTs). Preoperatively, 1 patient required continuous positive airway pressure (CPAP) and 1 needed supplemental oxygen for ventilatory support at final follow-up.

 

Emans and colleagues reported results on patients with TIS who underwent the procedure at Children’s Hospital in Boston from 1999 to 2005. (2005)  Thirty-one patients with fused ribs and TIS were treated; 4 patients had prior spinal arthrodesis with continued progression of deformity. Before surgery, all patients showed progressive spinal deformity, progressive chest deformity, or progressive hemithoracic constriction. The mean age was 4.2 years, and mean follow-up was 2.6 years (range 0.5 to 5.4). A 3-member team selected patients for surgery; cardiac function was also evaluated preoperatively. Surgery was performed using the Campbell technique for VEPTR. Device lengthening was planned for every 4 to 6 months, but often was longer due to intercurrent illness or difficulty with travel. The mean number of device lengthenings was 3.5 (range 0–10). Six patients had device exchanges for growth. In 30 patients, the spinal deformity was controlled and growth continued (1.2 cm/yr) in the thoracic spine during treatment at rates similar to normal children. In this study the final FVC was 73.5% of predicted levels. Pre-procedure, 2 patients were on ventilators and 3 patients required oxygen; at final follow-up, 1 patient required oxygen. Lung volume (measured by CT scan in cubic-cm) in the operated lung increased from 157 pre-operatively to 326 at the final follow-up visit.

 

Motoyama and colleagues from Children’s Hospital in Pittsburgh reported on follow-up of 10 patients with thoracic insufficiency with follow-up as long as 33 months. (2006)  Using a special portable pulmonary function testing device, they reported on lung function in 10 children who had placement of VEPTR. In this population, the median age was 4.3 years (range 1.8–9.8 years) at first test and they followed patients an average of 22 months (range 7–33 months) At baseline, FVC showed a moderate-to-severe decrease (69% of predicted), indicating the presence of significant restrictive lung defect. FVC increased significantly over time, with an average rate of 26.8% per year, similar to that of healthy children of comparative ages. In terms of percent-predicted values, FVC did not change significantly between the baseline and last test (70.3%), indicating that in most children studied, lung growth kept up with body growth.

 

The complications that occur with this device need to be considered by practitioners and families as they are discussing this procedure. Information on complications is summarized using data from the FDA review and the papers by Campbell and Emans. (2004, 2005)  About 25% of patients will experience device migration, including rib erosion. However, there does not seem to be significant long-term consequences from this. Approximately 10% of patients had infection-related complications. Brachial plexus injury or thoracic outlet syndrome occurred in 1% to 7% of these series. Skin sloughing was reported in 4 patients (15%) in the study published by Campbell.

 

No comparative trials have described the use of this device. Thoracic insufficiency occurs in a limited patient population; for example, the Boston center reported results on 31 children treated from 1999 to 2005. The natural history of progressive TIS is worsening pulmonary function and worsening pulmonary insufficiency.

 

Results from the series reported at different specialty centers demonstrate improvement and/or stabilization in key measures with use of this device in progressive TIS. This improvement is noted in measures related to thoracic structure (e.g., Cobb angle for those with scoliosis), growth of the thoracic spine and lung volumes, and stable or improved ventilatory status. While pulmonary function testing is very difficult in these patients, one study does demonstrate an age-specific increase in FVC and the studies report a final FVC in the range of 50%–70% of predicted value.

 

Given the usual disease course of worsening thoracic volume and ventilatory status, the stabilization/improvement in these measures would be highly unlikely in the absence of the intervention. Taken together, these various outcome measures demonstrate the positive impact of this procedure.

 

Thus, this intervention may be considered medically necessary in children with progressive thoracic insufficiency syndrome due to rib and/or chest wall defects. Given the complexity of this procedure and the patient population, use of this device should be performed in specialized centers. Preoperative evaluation requires input from a pediatric orthopedist, pulmonologist, and thoracic surgeon. In addition, preoperative evaluation of nutritional, cardiac, and pulmonary function (when possible) is required.

 

The policy was updated with a MEDLINE search through April 2008.  One additional series of 22 patients from another Children’s Hospital has been published. (Waldhausen, 2007).

 

 

 

 

  

  

 

 

 

 

A literature search conducted through June 2017 did not reveal any new information that would prompt a change in the coverage statement.