Quantification of Chest Wall Changes After Nuss Bar Removal Utilizing Three-dimensional Optical Surface Scans

Study Overview
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Brief Summary
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Pectus excavatum is the most common anterior chest wall deformity that affects up to 1:400 of newborns. If an operative correction is indicated, patients are often operated via the Ravitsch or Nuss bar procedure. The latter (i.e. the Nuss bar procedure) is the most commonly performed procedure. During this procedure one or more metal bars are inserted behind the sternum to push the sternum back into its normal position. These bars remain in situ for two-to-three years before being removed. Despite the fact that the Nuss bar procedure is regarded as an effective procedure, retraction may occur after removal. A recent study has investigated this phenomenon, utilizing three-dimensional (3D) optical surface scans acquired before and after Nuss bar removal. The authors found statistically significant changes to occur in chest wall dimensions directly after, as well as between 2 and 8 weeks after Nuss bar explantation, in comparison to the situation just prior to bar removal. They, moreover, found the time the bar was in situ to be predictive for retraction. However, the authors also stressed that further studies are needed to reinforce their preliminary findings and perform long-term assessments. Subsequently, a similar study with long-term assessments will be conducted.

Official Title
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Quantification of Chest Wall Changes After Nuss Bar Removal Utilizing Three-dimensional Optical Surface Scans

Conditions
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Pectus Excavatum

Intervention / Treatment
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* Other: 3D optical surface scan


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients that received 1 or more Nuss bar(s) to treat pectus excavatum and is/are scheduled to be removed due to the end of treatment. Exclusion Criteria: Patients in which the Nuss bar(s) or its stabilizers are or have been dislocated. Patients that received a second operation to treat any complications regarding the initial Nuss bar implantation. Patients with proven connective tissue diseases (e.g. Marfan's syndrome). Patients with a diagnosis of epilepsy (as the 3D scanner utilizes flashing light to acquire the torso topography) Patients that are not fit to remain in a standing position with their arms above shoulder level for a maximum of 60 seconds.
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 3D scan arm<br>This is a single arm study. Patients in this arm will receive a 3D scan just prior to, 2 weeks after, as well as 6 and 12 months after Nuss bar removal. | Other: 3D optical surface scan<br>* A 3D optical surface scan is acquired utilizing a handheld 3D scanner. Such a scanner is comparable to an ordinary photo camera, however, it also records depth.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean change in distance | The mean distance of thoracic wall changes | Changes from baseline (prior to surgery) to the situation 2 weeks after surgery, as well as after 6 and 12 months | 
| Maximum change in distance | The maximum distance of thoracic wall changes | Changes from baseline (prior to surgery) to the situation 2 weeks after surgery, as well as after 6 and 12 months | 
| Volumetric changes | The volumetric chest wall changes | Changes from baseline (prior to surgery) to the situation 2 weeks after surgery, as well as after 6 and 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Predictors of chest wall changes | Predictors of chest wall changes, assessed by multivariate analysis. | Changes in volume, mean and maximum distance from baseline to 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Three-dimensional optical surface imaging, Chest wall changes