Titanium Rib

Number: 0582

Table Of Contents

Policy
Applicable CPT / HCPCS / ICD-10 Codes
Background
References

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Policy

Scope of Policy

This Clinical Policy Bulletin addresses titanium ribs.

1. Medical Necessity

   Aetna considers the vertical expandable prosthetic titanium rib (VEPTR) medically necessary for treatment of thoracic insufficiency syndrome in skeletally immature persons.

   Note: Thoracic insufficiency syndrome may include flail chest syndrome, hypoplastic thorax syndrome (e.g., achondroplasia, Ellis van Creveld syndrome, Jarcho-Levin syndrome and Jeune's syndrome) as well as rib fusion and scoliosis.

2. Experimental and Investigational

   Aetna considers VEPTR experimental and investigational as a treatment for scoliosis (including congenital scoliosis, early onset scoliosis, idiopathic infantile scoliosis, kyphoscoliosis, and scoliosis associated with spinal muscular atrophy) without thoracic insufficiency syndrome and all other indications (e.g., chest wall repair in Poland syndrome, and hyperkyphosis) because of insufficient evidence in the peer-reviewed literature.

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Table:

CPT Codes / HCPCS Codes / ICD-10 Codes

Code	Code Description
Information in the [brackets] below has been added for clarification purposes.   Codes requiring a 7th character are represented by "+":
There is no specific CPT or HCPCS code for vertical expandable prosthetic titanium rib (VEPTR):
ICD-10 codes covered if selection criteria are met :
M41.00 - M41.9 M96.5	Scoliosis [if resulting in thoracic insufficiency syndrome]
M95.4	Acquired deformity of chest and rib [if resulting in thoracic insufficiency syndrome]
Q67.5	Congenital deformity of spine [if resulting in thoracic insufficiency syndrome]
Q76.3	Congenital scoliosis due to congenital bony malformation [if resulting in thoracic insufficiency syndrome]
Q76.6	Other congenital malformations of ribs [if resulting in thoracic insufficiency syndrome]
Q76.7	Congenital malformation of sternum [if resulting in thoracic insufficiency syndrome]
Q78.9	Osteochondrodysplasia, unspecified [if resulting in thoracic insufficiency syndrome]
Q77.6	Chondroectoderman dysplasia [if resulting in thoracic insufficiency syndrome]
S22.5XX+	Flail chest [if resulting in thoracic insufficiency syndrome]
ICD-10 codes not covered for indications listed in the CPB (not all inclusive):
M40.00 - M40.299	Kyphosis
Q76.411 - Q76.419	Congenital kyphosis
Q79.8	Other congenital malformations of musculosketetal system [Poland syndrome]

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Background

The vertical expandable prosthetic titanium rib (VEPTR) ("the titanium rib") (Synthes Spine, West Chester, PA) has been used in expansion thoracoplasty to treat thoracic insufficiency syndrome (TIS) in children.  In this procedure, the titanium rib is used as a chest wall distractor to directly treat segmental hemithorax hypoplasia from fused ribs by lengthening and expanding the constricted hemithorax, and improve the capacity of the underlying lung.  In addition, the titanium rib may indirectly correct scoliosis in the young child without the need for spine fusion.  Surgical alternatives to the titanium rib include in situ spinal fusion, implantation of plastic sheets, artificial ribs from cadaver donor ribs or autograft (rib sections split from contralateral ribs).  However, unlike the titanium rib, these surgical procedures are static treatments and are not adaptable as the child grows.

The U.S. Food and Drug Administration (FDA) has granted a humanitarian use device approval for VEPTR for treatment of thoracic insufficiency syndrome (TIS) in skeletally immature patients.  The FDA defines TIS as the inability of the thorax to support normal respiration or lung growth.  The FDA notes that, for purposes of identifying potential TIS patients, the categories in which TIS patients fall are as follows:

• Flail chest syndrome;
• Rib fusion and scoliosis;
• Hypoplastic thorax syndrome, including:
  
  
  • Achondroplasia
  • Ellis van Creveld syndrome
  • Jarcho-Levin syndrome
  • Jeune’s syndrome.

According to the FDA, the VEPTR device should not be used under the following conditions:

• Absence of proximal ribs for attachment of the VEPTR;
• Absent diaphragmatic function;
• Age below 6 months;
• Age beyond skeletal maturity;
• Inadequate soft tissue for coverage of the VEPTR;
• Inadequate strength of the bone (ribs/spine) for attachment of the VEPTR;
• Infection at the operative site;
• Known allergy to any of the device materials.

Approval as a humanitarian use device was based on the results of a 14-year, prospective, multi-center clinical trial of the VEPTR device in 247 children with TIS between 6 months of age up to the age of skeletal maturity.  Treatment with the VEPTR device was shown to maintain or improve the assisted ventilatory rating (AVR) scores in 92 % of patients, and the patient survival rate in the VEPTR clinical trial was 95.1 %.  The FDA determined that the probable benefits associated with patients implanted with the VETPR device outweigh the risk present for this patient population.  The FDA noted that TIS is frequently terminal with non-surgical treatment.  The FDA noted that the ability of VEPTR to be expanded allows growth of the thoracic spine and lungs while controlling severe scoliosis.  The use of the VEPTR may require a 6-week pre-operative period of halo traction.

Campbell et al (2004) reported on the outcome of VEPTR in 27 children (mean age of 3.2 years at time of surgery) with congenital scoliosis associated with fused ribs who were followed for a mean duration of 5.7 years.  Interval pulmonary function studies were analyzed to determine trends with regard to changes in vital capacity in the period following treatment.  Sixteen subjects had such interval studies, at a mean of 3.1 years (range of 2 to 6.7 years) post-operatively.  The first post-operative test demonstrated a mean vital capacity of 0.679 L (range of 0.37 to 1.7 L), or 49 % (range of 33 % to 68 %) of the predicted normal vital capacity, whereas the mean vital capacity at the time of follow-up was 0.91 L (range of 0.51 to 2.1 L), or 47 % (range of 25 % to 66 %) of the predicted normal vital capacity.  There was a total of 52 complications in 22 patients, with the most common being asymptomatic proximal migration of the device through the ribs in 7 patients.

Samdani et al (2009) examined bilateral use of the VEPTR attached to the pelvis as a novel treatment for children with severe, early onset scoliosis.  A total of 11 children were included in this study.  The authors conducted a retrospective review and collected the following data: clinical diagnosis, age at surgery, number of lengthening procedures, and complications.  In addition, pre- and post-operative radiographs were reviewed to measure maximum Cobb angle (both thoracic and lumbar), thoracic height, total spine height as measured from T1 to S1, thoracic kyphosis (T2 to T12), and lumbar lordosis (L1 to S1).  The average patient age at surgery was 71 months; the mean pre-operative thoracic Cobb angle was 81.7 degrees.  This angle was corrected to 50.6 degrees immediately post-operatively, and this correction was maintained; at the most recent follow-up the curves averaged 58 degrees.  Similarly, the pre-operative kyphosis (T2 to T12) angle measured 43 degrees pre-operatively, 23 degrees immediately post-operatively, and 37 degrees at the most recent follow-up evaluation.  Patients underwent a total of 41 lengthening procedures (average of  3.7 lengthening procedures per patient), and overall spine length increased from 23.1 cm pre-operatively, to 27.3 cm immediately post-operatively, to 29.4 cm at the final follow-up (average of 25 months).  Four (36.4 %) of the 11 patients experienced complications.  This was a small study; its findings need to be validated by future studies.

Shah and colleagues (2009) stated that surgical correction is generally indicated as the primary form of management in children with severe early onset scoliosis.  Even so, conservative, non-surgical treatment is always considered first, as surgical correction carries significant concomitant consequences, including but not limited to crankshaft phenomenon and, more importantly, inhibition of further spine, lung, and chest growth in skeletally immature patients.  Fusionless surgical procedures assuage some of these risks, as they are characteristically associated with techniques necessitating spinal fusion.  One device looks particularly promising in treating and managing severe early onset scoliosis – the VEPTR is a device that was initially targeted toward children with TIS.  Despite its promising results in correction of severe early onset scoliosis, as well as associated rib and chest wall deformities, the VEPTR nevertheless has a complication rate comparable to other fusionless techniques.  Continued modifications and research will hopefully beget a device that permits thoracic and spinal growth in skeletally immature patients yet with fewer post-operative complications.

In a retrospective study, Smith et al (2009) reviewed their experience in treating patients with idiopathic infantile scoliosis (IIS), especially as newer technologies, such as the VEPTR, emerge.  These investigators reviewed 31 consecutive patients with a primary diagnosis of IIS.  Patients were screened to ensure that there were no confounding congenital anomalies or co-morbidities that may have contributed to the spinal deformity.  The average age at the time of initial treatment was 25 months.  Treatment modalities included bracing, serial body casting, and VEPTR.  Pre-treatment, post-treatment, and most recent Cobb angles were compared to assess the overall curve correction, and patient charts were reviewed for the occurrence of complications.  Of the 31 patients, 17 were treated with a brace, 9 of whom had curve progression and went on to other forms of treatment.  Of the 8 who did respond, there was an overall improvement of 51.2 %. The 10 patients who received body casts, who had a mean pre-operative Cobb angle of 50.4 degrees, demonstrated an average correction of 59.0 %, with only a few skin irritations reported.  The 10 patients treated with VEPTR devices demonstrated a mean pre-operative Cobb angle of 90.0 degrees, and an average correction of 33.8 % was attained. Three of the VEPTR-treated patients (33 %) experienced minor problems. The authors concluded that these findings suggested that body casting has utility for patients with smaller, flexible spinal curves.  Bracing had limited utility, with high levels of progression and the need for secondary treatments. The VEPTR device appears to be a viable alternative for large-magnitude curves.

Reinker and colleagues (2011) examined if VEPTR controls progression in patients with kyphoscoliosis and, if so, what methods might be used to improve control of deformity progression in these patients.  These researchers retrospectively reviewed 14 patients who had VEPTR treatment of early-onset kyphoscoliosis.  Degrees of kyphosis and scoliosis before, during, and after treatment were measured, and levels of instrumentation, thoracic dimensions, and complications were recorded.  Minimum follow-up was 1.7 years (average of 5.8 years; range of 1.7 to 12.8 years).  While scoliosis was stabilized, kyphosis increased a mean of 22° at last follow-up.  Supple kyphosis became rigid during treatment.  Proximal cradle cut-out was a recurring problem.  Distal anchors placed too proximally had inadequate lever arms to control kyphosis.  The authors concluded that progression of kyphosis can be minimized during VEPTR treatment by early extension of the construct to the second ribs bilaterally, distal extension of hybrid constructs to the pelvis, use of bilateral hybrid VEPTR implants, and use of re-designed VEPTR constructs that enhance fixation at the upper end.  They noted that while these early findings suggest these devices control progression of kyphosis, longer follow-up with more patients are needed to confirm the concept in these patients.

Gadepalli and colleagues (2011) noted that VEPTR insertion and expansion has been advocated to increase thoracic volume and pulmonary function in patients with TIS.  These investigators reviewed their experience with VEPTR implantation to determine if lung function and growth is augmented, to determine the children's functional status, and if the scoliosis is controlled.  From 2006 to 2010, 29 insertions and 57 expansions were performed in 26 patients at the authors' institution.  Demographic data were reviewed in conjunction with complications, scoliosis angles, pulmonary function tests (PFTs), and computed tomography-guided 3D reconstructions to determine lung volumes; and quality of life scores were determined using a modified Scoliosis Research Society (SRS) questionnaire pre-operatively and post-operatively.  The groups were also stratified by age (because of lung growth potential), disease (congenital or infantile scoliosis, Jeune syndrome, neuromuscular, other structural thoracic disorders), and sex. Analyses using SPSS (SPSS, Chicago, Ill) were performed with p < 0.05 considered significant.  Each patient underwent 3.03 ± 1.8 surgeries, spending 0.97 ± 1.8 days in the intensive care unit and 4.41 ± 6 days in the hospital for each procedure.  Mean age was 90.7 ± 41 months.  Of the 36 complications, most were because of infection (n = 12), half requiring operative repair (hardware removal).  The average PFT percent predicted values for forced expiratory volume in 1 second, forced vital capacity, and RV were 54.6 ± 22, 58.1 ± 24, and 145.3 ± 112, respectively, pre-operatively and 51.8 ± 20, 55.9 ± 20, and 105.6 ± 31, respectively, post-operatively.  The lung volumes measured by computed tomography when corrected for age do not increase significantly post-operatively.  The mean Cobb measurement for the pre-operative major curves was 64.7° and post-operatively was 46.1° for those curves measured pre-operatively, for a 29 % curve improvement.  All post-operative curves had a mean of 56.4° and 58.1° at final follow-up, a 3 % curve increase.  The SRS scores for patients remained unchanged and no statistical difference was seen from pre-operative to post-operative values.  No statistically significant difference was seen in complications, PFT (forced expiratory volume in 1 second, forced vital capacity, RV), lung volumes, scoliosis angles, and SRS scores between sex, age, and disease categories.  The authors concluded that there was mild improvement in scoliosis angles but no improvement in lung function and volume.  Scoliosis Research Society scores indicated that the children have near normal function both before and after VEPTR placement.  Pulmonary function, lung volume, and patient subjective assessments did not increase dramatically after VEPTR placement, although scoliosis angles improved.

Lieber et al (2012) noted that various surgical techniques have been described for repair of chest wall defects in Poland syndrome.  These investigators described the case of a 16-year old boy who underwent autologous rib transposition after sternal osteotomy.  Chest wall stabilization was achieved using a combination of K-wires and VEPTR.  Reconstruction of the soft tissue defect was accomplished by combined latissimus dorsi muscle flap and Permacol patch.  This approach might be considered an effective 1-stage treatment option of this condition in post-pubescent boys.  The findings of this case study need to be validated by well-designed studies.

In a retrospective analysis of prospectively collected data of a case series, Abol Oyoun et al (2014) reported the preliminary results of the use of VEPTR in an Eiffel Tower construct in children with neuromuscular scoliosis in regard to coronal and sagittal profiles, space available for the lungs (SAL), and spinal growth.  The report listed the complications we faced during the follow-up of 1.33 years after the index procedure.  A total of 20 non-ambulatory children (mean age of 8.9 years) with neuromuscular scoliosis were included in this analysis.  Their primary diagnoses were myelomeningocele (n = 7), cerebral palsy (n = 3), spinal muscular atrophy (n = 2), myopathies (n = 3), arthrogryposis (n = 1), and syndromic scoliosis (n = 4).  All 20 patients received percutaneous rib-to-pelvis VEPTR implantation.  Mean operative time was 2 hours, and mean hospital stay was 12 days.  None of them needed blood transfusion.  They underwent 20 primary implantations and 39 lengthenings.  Patients were assessed based on physiologic measures, that is, the radiographic improvement of their scoliosis, SAL, pelvic tilt, spinal height, and sagittal and coronal decompensation.  At the latest follow-up, thoracolumbar curvature improved significantly (65.7° ± 20.5° to 49.9° ± 15.7°), as did lumbar curvature (61.6° ± 19.5° to 35° ± 21.2°), thoracic (17.2 ± 2.3 to 20 ± 2.3 cm) and lumbar spinal height (9.9 ± 1.7 to 11.9 ± 1.8 cm), SAL (86.5 ± 8.9 to 97 ± 10), pelvic obliquity (12.5^° ± 8^° to 5.2^° ± 5.2^°), and the ilio-lumbar angle (15° ± 8° to 10.06° ± 7.1°).  Nine patients suffered complications in the form of proximal cradle migration (n = 5), implant breakage (n = 5), deep wound infection (n = 3), and dislodged iliac hooks (n = 2).  The authors concluded that early results of VEPTR for neuromuscular scoliosis are encouraging; follow-up till skeletal maturity will best determine future indications.

In a review on "Surgical aspects of spinal growth modulation in scoliosis correction", Jain and colleagues (2014) states that "In patients with early onset scoliosis, a hybrid construct with vertebral stapling and growing rods or a vertical expandable prosthetic titanium rib has been suggested.  A failure of the spinal growth modulation procedure does not preclude spinal fusion.  None of the devices for spine growth modulation have been approved by the FDA for human use and are still investigational.  Early results are promising, and continued clinical studies are necessary".

Dede and associates (2014) states that "The experience with growing rods has been increasing, along with expanding indications.  Several self-lengthening instrumentation systems have been introduced aiming for guided spinal growth.  There has been considerable progress in the clinical and laboratory studies using magnetically controlled growing rod constructs.  Growing rods and vertical expandable prosthetic titanium rib (VEPTR) systems provide deformity control while allowing for spinal growth along with a risk of spontaneous vertebral fusions.  VEPTR may cause rib fusions as the implants overlie the thoracic cage and, therefore, the use in pure spinal deformities is controversial.  There have been exciting recent advances concerning the treatment of spinal deformities in young children.  Despite these advances, the surgical treatment of early-onset scoliosis remains far from optimal and more development is on the way".

Karlin et al (2014) stated that Jarcho-Levin syndrome represents a spectrum of clinical and radiographic irregularities including abnormal vertebral segmentation or formation defects, rib deformities, and short-trunk dwarfism.  These abnormalities cause reduced thoracic capacity for lung development, resulting in TIS.  These investigators reviewed outcome measures related to scoliotic curve correction, thoracic growth, and respiratory function following VEPTR treatment in patients with Jarcho-Levin syndrome.  A total of 29 patients with Jarcho-Levin syndrome, sub-classified as spondylo-costal dysostosis (SCD) or spondylo-thoracic dysplasia (STD), were treated with VEPTR expansion thoracoplasty and followed for at least 2 years since the initial implantation.  Spinal and respiratory measures were collected prior to the initial VEPTR implantation, immediately after implantation, and at the most recent follow-up.  Vertical expandable prosthetic titanium rib treatment was associated with improved clinical respiratory function and with increases in thoracic height (by 50 % in the SCD group and 42 % in the STD group) and thoracic width (by 37 % in the SCD group and 28 % in the STD group).  Vertical expandable prosthetic titanium rib treatment resulted in scoliosis curve correction (improvement in the Cobb angle of 41 % [22°] in the SCD group and 26 % [3.7°] in the STD group) and in improved thoracic symmetry in patients with SCD.  Patients with SCD displayed increased lumbar lordosis, and both groups of patients developed increased thoracic kyphosis approaching normal.  The authors concluded that VEPTR treatment improved thoracic symmetry, controlled spinal deformity, and was associated with improved clinical respiratory function.

O’Brien et al (2015) noted that Jeune’s syndrome (JS) often results in lethal TIS.  Since 1991, VEPTR dynamic postero-lateral expansion thoracoplasty was used at these investigators’ institution for treatment of JS.  This study evaluated the safety and effectiveness of this procedure.  A total of 24 JS patients were treated, 2 lost to follow-up, 17 with a minimum of 2-year follow-up retrospectively reviewed for clinical course: Assisted ventilation rate, respiratory rate, capillary blood gases, pulmonary function tests, and complications.  Upright antero-posterior/lateral radiographs were measured for Cobb angle, kyphosis, lordosis, thoracic width, and thoracic/lumbar spinal height.  Computed tomography scan lung volumes were obtained in 12 patients.  Mean age at initial implant was 23 months (7 to 62) with an average 8.4 years (2.3 to 15.6) of follow-up.  Average chest width increased from 121 to 168 mm at follow-up (p < 0.001).  Pre-operatively, 7/17 (41 %) patients had scoliosis.  The remainder developed scoliosis during treatment, 8 requiring additional implants.  Thoracic and lumbar spinal height was normal pre-operatively and stayed normal during treatment.  Thoracic kyphosis/lumbar lordosis was stable.  Average computed tomography scan total lung volumes increased 484 to 740 mm (p < 0.001), and assisted ventilation rate status tended to improve (p = 0.07).  Average forced vital capacity was 34 % predicted at first test and 27 % predicted at last follow-up.  Early demise after surgery was common with multi-system disease.  Mean respiratory rate decreased from 35 to 24 bpm at last follow-up (p < 0.05).  Survival rate of the 22 patients was 68 %.  Migration of the rib cradles/titanium slings occurred in 12 patients, superficial infections in 5 patients, deep infections in 4 patients, and wound dehiscence in 5 patients.  Infection rate was 4.6 % per procedure.  The authors concluded that the survival rate in JS with surgery was nearly 70 % (compared with 70 % to 80 % mortality without treatment) with less ventilator dependence.  Both C1 stenosis and scoliosis are common in JS.  Spinal height in JS is normal.  Complications are frequent, but tolerable in view of the clinical gains and increase in survival.

Watts (2016) stated that TIS is the inability of the thorax to support normal respiration or lung growth.  One treatment to address the thoracic deformities associated with the syndrome is placement of a VEPTR.  The goal is to restore thoracic volume, symmetry, and function and to allow for growth of the thorax in skeletally immature children.  The author stated that continued follow-up of patients as they reach adulthood to monitor long-term effects of VEPTR implantation is an important area of research in which data are limited.  Long-term follow-up of patients treated with VEPTR devices and growing rods are important in examining improvements in the patients’ TIS, pulmonary function, and, ultimately, long-term survival, which is currently unknown.

LaGreca and colleagues (2017) determined the rate of intra-operative neurological monitoring (IONM) alerts and neurological injury during VEPTR treatment and evaluated the utility of IONM during VEPTR expansion procedures in patients who have not previously had neurological injury or IONM alerts.  After institutional review board approval, VEPTR procedures and IONM records were reviewed at 17 institutions for patients treated with VEPTR from 2005 to 2011.  All consecutive cases in patients with minimum 2-year follow-up were included.  Patients with prior history of growing rods or other invasive spine-based surgical treatment were excluded.  Surgeries were categorized into implant, revision, expansion, and removal procedures. Cases with IONM alerts or neurological injury had additional detailed review.  Descriptive statistics were used for data analysis.  In total, 2,355 consecutive VEPTR procedures (352 patients) consisting of 299 implant, 377 revision, 1,587 expansion, and 92 removal procedures were included.  In total, 620 VEPTR procedures had IONM, and 539 of those had IONM records available for review.  IONM alerts occurred in 9/539 procedures (1.7 %): 3/192 implants (1.6 %), 3/58 revisions (5.2 %), and 3/258 expansions (1.2 %).  New neurological injury occurred in 3/2,355 procedures (0.1 %), 3/352 patients (0.9 %).  All 3 injuries were in implant procedures, only 1 had an IONM alert.  All 3 had upper extremity motor deficits (1 had sensory deficit also).  All had full recovery at 17, 30, and 124 days post-injury.  One patient without prior neurological injury or IONM alert had an IONM alert during expansion that resolved after an increase in blood pressure.  The remaining IONM alerts during expansions were all in children with prior IONM alerts during implant, revision, or exchange procedures.  The authors concluded that the highest rate of neurological injury in VEPTR surgery was found for implant procedures.  There were no instances of neurological injury during VEPTR expansion, revision, or removal procedures.  They stated that IONM did not identify new neurological injuries in patients undergoing VEPTR expansion who did not previously have a history of IONM signal change or neurologic injury.

Congenital Scoliosis

Balioglu et al (2015) evaluated the effect of VEPTR on growth in congenital scoliosis (CS). A total of 4 female patients in whom VEPTR was applied were retrospectively evaluated.  Antero-posterior (AP) and lateral Cobb angles that were measured pre-operatively and during the last control, space available for lung (SAL), T1-S1 and T1-T12 distances, coronal and sagittal balances were compared.  The authors concluded that VEPTR may provide a good correction, and they observed a growth in the spine height and SAL following the treatment of congenital deformities.  Moreover, they stated that long-term, multi-center, prospective studies that compare the spinal height, respiratory functions, the severity of the deformity, and the spinal balance are needed in order to evaluate the effectiveness of VEPTR for the treatment of CS.

In a case-series study, Murphy et al (2016) examined the effectiveness of VEPTR in sagittal/coronal curve correction and spine growth and compared its complication rate to the use of VEPTR in other conditions and to other treatment methods used for CS. A multi-center database was queried for patients with CS without fused ribs treated with VEPTR.  Antero-posterior and lateral radiographs were used to measure parameters at 3 time-points (pre-operative, immediate post-operative, and latest follow-up): coronal Cobb angle, sagittal kyphosis, and thoracic and lumbar spine heights.  Clinical data included age, time to follow-up, and complications.  A total of 25 patients (13 females, 12 males) were identified.  The average age at implantation was 5.7 years, with an average follow-up of 50 months.  Several parameters improved from pre-operative to latest follow-up: coronal Cobb angle (69 to 54 degrees, p < 0.0001), thoracic spine height (T1-T12) in the AP (13.3 to 15.9 cm, p < 0.0001) and lateral (14.8 to 17.4 cm, p = 0.0024) planes, and lumbar spine height (L1-S1) in the AP (8.8 to 11.4 cm, p < 0.0001) and lateral (9.9 to 11.9 cm, p = 0.0002) planes.  Kyphosis increased over the study period (36 to 41 degrees, p = 0.6); 15 patients (60 %) had 41 complications (average of 2.75; range of 1 to 12).  Twenty-eight complications (68%) were device-related, and 13 (32 %) were disease-related.  The most common complications were infection, wound dehiscence, and device migration; 6 complications (15 %) altered the course of treatment.  Thoracic spine height increased 79 % of expected growth.  The authors concluded that VEPTR is an effective treatment for patients with CS without fused ribs, as evidenced by improved radiographic parameters and increased spinal height, with a complication rate which is high but similar to other methods of treatment.  The main drawbacks of this study were its small sample size (n = 25) and medium-term follow-up (average of 50 months); thus, the level of evidence was low (Level IV).

Weiss and Moramarco (2016) noted that CS is a lateral deformity of the spine with a disturbance of the sagittal profile caused by malformations of vertebra and ribs. Typically, early surgical intervention is the suggested treatment (before 3 years of age) for young patients with CS.  While a previous study was conducted in 2011 to investigate long-term studies supporting the necessity for this recommendation and no evidence was found, this current review, is an updated search for evidence published from 2011 through March 2015.  This also failed to find any prospective or randomized controlled trials (RCTs) to support the hypothesis that spinal fusion surgery in patients with CS should be considered as evidence-based treatment.  Contradictory results exist on the safety of hemi-vertebra resection and segmental fusion using pedicle screw fixation.  When using the VEPTR device, studies showed a high rate of complications exist.  The authors concluded that it is difficult to predict the final outcome for patients with CS.  However, it is possible that many patients with CS may be able to avoid spinal surgery with the application of advanced bracing technology.  Thus, it is only prudent to advocate for conservative management first before spinal surgery is considered.

In a prospective, multi-center, observational cohort study, El-Hawary and associates (2017) evaluated the effectiveness of VEPTR in preventing further progression of scoliosis without impeding spinal growth in children with progressive early-onset scoliosis (EOS) without rib abnormalities.  Erect radiographs were analyzed for coronal and sagittal curve and height measurements at pre-implant, immediate post-operative, and at 2-year follow-up.  A total of 63 patients met inclusion: 35 males and 28 females were included in this study.  Mean age at time of implantation was 6.1 ± 2.4 years.  Etiologies included congenital (n = 6), neuromuscular (n = 36), syndromic (n = 4), and idiopathic (n = 17).  The mean follow-up was 2.2 ± 0.4 years.  Scoliosis (72 ± 18 degrees) decreased after implant surgery (47 ± 17 degrees) followed by slight increase at 2-year follow-up (57 ± 18 degrees), p < 0.0001.  Kyphosis (48 ± 22 degrees) also showed significant decrease after implantation (40 ± 14 degrees), but increased after 2 years (48 ± 16 degrees), p < 0.0001.  Coronal spine height measurements including T1 to T12 (15.7 ± 3 cm) and T1 to S1 (25 ± 6 cm) showed significant increases after implantation surgery (17.7 ± 4 cm and 28.6 ± 6 cm, respectively) and at 2 years (18.4 ± 4 cm and 29.1 ± 5 cm, respectively), p < 0.0001.  The increase in coronal spine height represented 144 % of expected age-matched T1 to T12 growth and 193 % of expected age-matched T1 to S1 growth.  Similarly, sagittal spine length of T1 to T12 and T1 to S1 increased from 16.9 ± 2.7 cm and 27.1 ± 3.9 cm, respectively pre-operatively to 19.7 ± 3.5 cm and 31.9 ± 5.1 cm, respectively at 2-year follow-up, p < 0.0001.  The instrumented spine segment continued growth from 25.8 ± 5.2 cm after implantation to 27.4 ± 5.3 cm at 2-year follow-up, p < 0.0001; 31 patients (49 %) had at least 1 complication with total of 58 complications.  The authors concluded that at 2-year follow-up, VEPTR was effective in treating EOS without rib abnormalities with 86 % of patients having an improvement in scoliosis and 94 % of patients having an increased spinal height as compared with pre-operative values.  This study proved that spine continued to grow after VEPTR instrumentation during the distraction phase.  This amount of growth represented about 40 % for T1 to T12 and 31 % for T1 to S1 spine of the expected age-matched growth based on Dimeglio reference numbers.  The authors found this growth important as it proved continuous spine growth with VEPTR treatment.

Hyperkyphosis

Gantner and colleagues (2018) noted that in several studies, VEPTR implants have shown good scoliosis control in children with the longest reported follow-up of 3.6 years.  For growing rods, recent studies suggested a decreased efficiency of correction starting just after that time.  To the authors’ knowledge, no long-term results of children with VEPTR treatment are available.  These investigators evaluated spinal deformity in scoliotic children and examined correction potential of VEPTR implants at several time-points of treatment, particularly after long-term follow-up.  They performed a retrospective case series of children with spinal deformity and VEPTR treatment with analysis of clinical and radiological data pre- and post-VEPTR implantation and every 2 years during the follow-up period.  A total of 32 patients with spinal deformity and VEPTR treatment comprised the patient sample.  Patients had a primary VEPTR implantation due to spinal deformity and thoracic insufficiency syndrome and repeated lengthening procedures every 6 months.  Clinical data were assessed and radiological parameters were analyzed.  The main thoracic scoliotic curve and associated curves as well as kyphosis, lordosis, pelvic obliquity, and spinal length were measured in all radiographs until the end of VEPTR treatment or the last available examination.  Development of the different parameters during follow-up was evaluated and statistical analysis was performed with Statistica version 13.0.  Directly after VEPTR implantation, thoracic and lumbar curves corrected significantly, were stable at 2.8-year follow-up, and increased at 5.5-year follow-up, whereas cervical scoliosis was not affected by the treatment.  The sagittal profile was initially improved both in kyphosis and lordosis.  However, at 5.5-year follow-up, hyperkyphosis had deteriorated beyond the initial deformity.  Pelvic obliquity was significantly restored especially in neuromuscular patients, and increasing spinal length was achieved within the 5.5-year follow-up.  The authors concluded that in children with spinal deformity, implantation of the VEPTR device sufficiently corrected the deformity in all planes.  During long-term follow-up, scoliosis increased slightly and was rather well-controlled, whereas the implant system was not able to prevent deterioration of hyperkyphosis.  Pelvic obliquity was well-balanced and spinal lengthening was achieved during long-term follow-up.

Early Onset Scoliosis

Studer and Hasler (2020) stated that the VEPTR device was originally developed for the treatment of thoracic insufficiency syndrome with the aim of improving respiratory function of affected patients.  Although clinically obvious, the changes in pulmonary function of VEPTR-treated patients are difficult to evaluate when using common lung function tests, and newer techniques based on functional magnetic resonance imaging (MRI) are currently being examined.  The potential of improving lung function and simultaneously controlling the spinal deformity has continuously broadened the spectrum of indications for VEPTR, not least due to the frequent reports of complications with spine-based traditional growing rods (TGR).  However, the initial enthusiasm of spine-sparing deformity correction has progressively subsided with the increasing number of reports on complications, including the detection of extra-spinal ossifications along the implants and across ribs.  The avoidance of repetitive surgical implant lengthening with the availability of motorized distraction-based implants has further diminished the use of VEPTR, especially in the absence of volume-depletion deformities of the thorax.  In view of the still scarce reporting on the ultimate strategy of VEPTR treatment and the lack of long-term follow-up of patients receiving growth-sparing surgery, only limited conclusions could be drawn so far.  The authors concluded that based on the available reports, the intended deformity corrections with final fusion surgeries can be achieved to a rather limited extent, while the complication and re-operation rates are still very high.  Furthermore, these researchers stated that reports on long-term follow-up of patients after completed VEPTR treatment are still pending, and the most important prerequisite for the development of an evidence-based algorithm in the decision-making process for the final strategy at the end of growth has also not been established.

Bachabi and associates (2020) noted that distraction-based techniques allow spinal growth until skeletal maturity while preventing curve progression.  Two multi-center EOS databases were used to identify patients with idiopathic spine abnormalities treated with TGR or VEPTR.  Patients underwent at least 4 lengthening and had at least 5-year follow-up.  Significance was set at p < 0.05.  A total of 50 patients were treated with TGR and 22 treated with VEPTR.  Mean (± SD) age at surgery was 5.5 (± 2.0) years for the TGR group versus 4.3 (± 1.9) years for the VEPTR group (p = 0.044); other demographic parameters were similar.  VEPTR patients had more procedures (mean of 15 ± 4.2) than TGR patients (mean of 10 ± 4.0) (p = 0.001).  Unilateral constructs were present in 18 % (4 of 22) of VEPTR and 16 % (8 of 50) of TGR patients.  Bilateral constructs spanned a mean 2.1 additional surgical levels and exposed patients to 1.6 fewer procedures than unilateral constructs.  Curve correction was similar between bilateral and unilateral constructs.  TGR patients experienced greater curve correction (50 %) than VEPTR patients (27 %) (p < 0.001) and achieved a greater percentage of thoracic height gain (24 %) than VEPTR patients (12 %) (p = 0.024).  At latest follow-up, TGR patients had better maintenance of curve correction, less kyphosis, and 15 % greater absolute gain in thoracic height versus VEPTR patients.  TGR patients had a lower rate of wound complications (14 %) than VEPTR patients (41 %) (p = 0.011).  The authors concluded that in patients with idiopathic EOS, TGRs produced greater initial curve correction, greater thoracic height gains, less kyphosis, and lower incidence of wound complications compared with VEPTR.  Level of evidence: Level III.

In a retrospective analysis of prospectively collected data of a case-series study, Almajali and co-workers (2020) reported their experience and results regarding the use of VEPTR in children with scoliosis in regard to coronal profiles (length and deformity angle), spinal growth, and the complications faced during the follow-up of 2 years after the index procedure.  A total of 40 children with scoliosis of different etiologies were included in this analysis.  Their primary diagnoses were neuromuscular scoliosis in 13, juvenile idiopathic scoliosis in 12, congenital Scoliosis in 8, syndromic patients 5 and 2 with arthrogryposis.  All 40 patients received percutaneous rib-to-pelvis or rib-to-vertebra or rib-to-rib VEPTR implantation between January 2016 and January 2018.  None of them needed blood transfusion.  They underwent 56 primary implantations, 16 (40 %) bilateral system and 24 (60 %) unilateral followed by lengthening procedure in a period of 4 to 6 months.  Subjects were evaluated based on mechanical measures, that is, the radiographic improvement of their scoliosis, spinal height, and sagittal and coronal correction, which are measured and compared pre-operatively, immediately post-operatively and at 2 years follow-up, complication encountered during this period were also counted.  The average initial correction in Cobb angle immediately after the index surgery was 14.4° (5° to 26°) and the average final correction of Cobb which was measured after the last expansion procedure (Cobb angle of the major curve measured after last expansion minus initial pre-operative Cobb angle of the major curve) was 7.3° (12 %).  The average of pre-operative coronal T1 to S1 length was 25.6 cm with an average initial correction achieved immediately after implantation of VEPTR of 2.8 cm (1.2 to 5.1 cm) which was 10.9 %, and the average coronal length gain at 2-year follow-up was 5.7 cm (3.7 to 9.8 cm) that was 22.2 %.  Complication occurred in 18 of the patients (45 %).  The authors concluded that early results of VEPTR for childhood scoliosis were encouraging.  Moreover, these researchers stated that follow-up investigations until skeletal maturity will best determine future indications.

Peiro-Garcia and colleagues (2021) stated that EOS is a challenging problem for spine surgeons that has been managed with different growth-friendly instrumentation systems.  Although rib-based devices encourage spinal growth via regular lengthening, the high rate of complications and re-operations led these researchers to use spine-based devices such as magnetically controlled growing rods (MCGRs) to mitigate this concern.  These investigators examined if surgical treatment of EOS with MCGRs or a VEPTR resulted in fewer short-term (24 months) complications and re-operations.  A total of 35 EOS patients were included in the study; 20 were included in the VEPTR group, and 15 patients were included in the MCGR group.  Demographic data and 2 years of post-operative complications and re-operations were reviewed retrospectively.  As secondary outcomes, radiographic outcomes were reported pre-operatively and 1 year after surgery.  Indications for this technique and complications were collected from the charts.  Demographic data showed no significant differences between the 2 groups.  Significant differences were found in the complications rate at 2 years, with 65 % complications in the VEPTR group and 13.3 % complications in the MCGR group (p < 0.001).  The re-operation rate at 2 years was also significantly higher in the VEPTR group, with 50 % versus 13.3 % in the MCGR group (p = 0.0009).  As secondary outcomes, radiological parameters such as main curve Cobb angle correction (p = 0.001) and apical vertebral translation (p = 0.002) were significantly higher in the MCGR group.  Significant differences were also found in sagittal profile parameters; T1 to T12 and T1 to S1 were significantly higher in the MCGR group (p < 0.001).  The authors concluded that according to the findings of this study, VEPTR had significantly higher complication and re-operation rates at 2 years post-surgery compared with MCGR; and longer-term follow-up is needed to examine if the benefits persist after 2 years as well as long-term complications.  Level of Evidence = IV.

The authors stated that the drawbacks of this study included its retrospective, single-center design, and the small sample size (n = 20 in the VETPR group); this may limit the conclusions.  One of the challenges in designing studies in EOS that allow for meaningful comparisons of surgical processes and outcomes was the heterogeneity of this patient population, which may also affect the findings of this study.  In this study, no significant differences were found in etiology, and the same indications for surgery were used in both groups.  Another drawback was the relatively short-term follow-up (2 years).  Despite the reported increase in complications of growth-friendly procedures with increased follow-up, the purpose of this study was to compare the early complications rate (2 years) for patients with EOS managed with VEPTR versus MCGR.  Finally, the high complication rate in the VEPTR group may suggest that the surgeons were in their learning curve; the surgeons had been using VEPTR since 2004, whereas the surgeons started using MCGR in 2015.  The surgeons decided to switch to magnetic growth-friendly devices after promising results in previous studies with MCGR.

Elmallah et al (2021) stated that patients who have neuromuscular scoliosis, such as cerebral palsy (CP), often develop spinal deformities that negatively impact quality of life (QOL).  The VEPTR was designed for TIS; however, it has also been used in patients with CP with restrictive lung disease and spine deformity.  Few studies reported on VEPTRs in neuromuscular scoliosis; however, none reported on their use specifically in patients with CP.  In a retrospective study, these researchers examined if VEPTRs could improve spinal deformity and TIS in these patients.  They carried out a chart review of all patients with CP and scoliosis treated with a VEPTR between 2008 and 2017.  A total of 8 patients were eligible for this study.  The mean follow-up was 4 years.  Outcomes evaluated were Cobb angle, pelvic obliquity, space available for lung ratio (SAL), T1 to S1 height, and complication rates.  A p < 0.05 was used for statistical significance.  There were significant post-operative improvements in Cobb angle, pelvic obliquity, and T1 to S1 height, but no statistical difference in SAL.  Prior to final fusion, the mean number of VEPTR lengthening procedures was 3.  The mean time from index surgery to final fusion was 3.7 years.  The most common complications were infection (62.5 %) and wound dehiscence (25 %).  Only 25 % of patients did not have a complication.  The authors concluded that patients with scoliosis secondary to CP could successfully be treated with VEPTR constructs, which demonstrated improvements in radiographic outcomes, despite no corresponding significant improvements in TIS at the final follow-up.  However, there are many other growing rod constructs available to these patients, including TGRs and MCGRs.  Furthermore, these alternative constructs offer improved complication profiles.  Because of this, the authors no longer employ VEPTR constructs in children with CP or other similar neuromuscular diagnoses.

Johnson et al (2021) noted that surgical treatment of EOS with rib-based implants such as the VEPTR is associated with a high rate of complications including surgical site infection, skin breakdown, and implant migration.  Many of these complications warrant the need for unplanned re-operations, increasing the burden on an already vulnerable patient population, and introducing the further risk of infection.  To provide insight into the risks of early intervention, these investigators examined the relationship between initial device implantation before the age of 3 and the rate of unplanned re-operation.  These researchers carried out a retrospective review of all patients at a single institution who had undergone VEPTR insertion for EOS with at least a 2-year follow-up from 2007 to 2016.  Patients were stratified into the case-cohort (0 to 2 years of age) or the comparison cohort (3 to 10 years of age) based on age at the time of device implantation.  Multi-variate regression accounting for age and scoliosis etiology was carried out to identify factors predictive of unplanned reoperation.  A total of 137 of 185 patients treated with VEPTR were identified with 76 (56 %) undergoing at least 1 unplanned re-operation during the study time period.  There were 68 and 69 patients in the age 0- to 2-year and 3- to 10-year cohorts, respectively.  Patients aged 0 to 2 years underwent a higher number of total procedures compared with those aged 3 to 10 (13.1 ± 6.5 versus 10.6 ± 4.8, p = 0.032).  A significant difference was found in the rate of unplanned re-operation between the 2 cohorts with 44 (65 %) patients aged 0 to 2 and 32 (46 %) patients aged 3 to 10 undergoing at least 1 unplanned re-operation (p = 0.031).  Binary logistic multi-variate regression accounting for age and scoliosis etiology demonstrated that patients aged 0 to 2 had a significantly greater odds of undergoing an unplanned re-operation (odds ratio [OR]= 3.050; 95 % confidence interval [CI]: 1.285 to 7.241; p = 0.011) compared with patients aged 3 to 10 years.  The authors concluded that overall, EOS patients aged 0 to 2 at initial VEPTR implantation were up to 3 times higher risk of undergoing an unplanned re-operation compared with those aged 3 to 10.  Level of Evidence = III.

Scoliosis Associated with 1p36 Deletion Syndrome

Majid et al (2022) stated that monosomy 1p36 deletion is a rare syndrome that consists of developmental delay, intellectual disability, seizures, hearing and vision defects, brain anomalies, orofacial clefting, congenital heart defects, cardiomyopathy, renal anomalies, and scoliosis.  These investigators reported the case of an 8-year-old boy who presented to the orthopedic clinic with spinal deformity with a background of 1p36 deletion syndrome.  The treatment modalities at this age include growing rods, VEPTR, or posterior spinal fusion.  Keeping in view the challenges in this case due to multi-organ involvement and severe intellectual disability, these researchers decided to manage this patient with a VEPTR device to prevent the progression of scoliosis and allow spinal growth.  The authors concluded that VEPTR instrumentation for progressive scoliosis in p36 deletion syndrome is an effective mode of treatment and led to favorable outcomes.  Moreover, these researchers recommended that further study projects should be carried out to reach a more comprehensive approach and management guidelines for scoliosis in patients with 1p36 deletion syndrome.

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References