MyPectus: First-in-human pilot study of remote compliance monitoring of teens using dynamic compression bracing to correct pectus carinatum

Non-surgical approaches to the management of chest wall deformities

Chest wall deformities in children encompass a broad spectrum of disorders but pectus excavatum and carinatum are by far the most common. Treatment varies substantially by center, and depends on patient symptoms, severity of disease, and surgeon preference. Historically, surgical approaches were the mainstay of treatment for these disease processes but new advances in non-surgical approaches have demonstrated reasonable results in select patients. These non-surgical approaches include vacuum bell therapy, autologous fat grafting and hyaluronic acid injections for pectus excavatum, and orthotic brace therapy for pectus carinatum. There is debate with regards to optimal patient selection for these non-surgical approaches, as well as other barriers including reimbursement issues. This paper will review the current non-surgical approaches to chest wall deformities available, including optimal patient selection, treatment protocols, indications, contraindications, and outcomes.

Ravitch Surgery or Dynamic Compression Bracing for Pectus Carinatum: A Retrospective Cohort Study

BACKGROUND

Pectus carinatum is a pediatric condition that can be treated by dynamic compression system (DCS) bracing or surgery. Several publications on DCS bracing or surgery are available; however, they do not compare both treatments.

METHODS

Over a 10-year period, 738 patients with pectus carinatum were treated at the Amsterdam Pectus Center (Amsterdam, The Netherlands). This study describes this 10-year experience and the results of both treatments.

RESULTS

Of the 631 patients who underwent DCS bracing treatment, 553 finished treatment, and 78 patients are still under treatment. A total of 73.8% (n = 408) of these patients finished treatment successfully, 13.6% (n = 75) experienced treatment failure, and 12.7% (n = 70) were lost to follow-up. The success rate decreased with an increasing pressure of initial compression (84.2%-67.3%). Marfan syndrome and Poland syndrome were associated with unfavorable results. Ravitch surgery was performed in 105 patients, with a success rate of 92.4%. Complications occurred in 32.4% of patients, and 6.7% of patients had complications for which surgery was needed. No relationship was found between osteotomy or sternal fixation and outcomes or complications. The Abramson procedure was performed in 2 patients.

CONCLUSIONS

DCS bracing should be the treatment of choice in patients with pectus carinatum because of its noninvasiveness, good results, and lower complication rate compared with surgery. Besides pressure of initial correction, motivation is an important factor influencing outcomes, and compliance remains a major challenge in treating pectus carinatum using DCS bracing. Bracing patients before their growth spurt should be discouraged. Patients with a higher pressure of initial compression (>8.0-8.5 psi) and Marfan syndrome or Poland syndrome have poorer outcomes. In those patients, surgery may be considered.

Remote Monitoring System of Dynamic Compression Bracing to Correct Pectus Carinatum

Pectus carinatum (PC) is a chest deformity caused by disproportionate growth of the costal cartilages compared with the bony thoracic skeleton, pulling the sternum forwards and leading to its protrusion. Currently, the most common non-invasive treatment is external compressive bracing, by means of an orthosis. While this treatment is widely adopted, the correct magnitude of applied compressive forces remains unknown, leading to suboptimal results. Moreover, the current orthoses are not suitable to monitor the treatment. The purpose of this study is to design a force measuring system that could be directly embedded into an existing PC orthosis without relevant modifications in its construction. For that, inspired by the currently commercially available products where a solid silicone pad is used, three concepts for silicone-based sensors, two capacitive and one magnetic type, are presented and compared. Additionally, a concept of a full pipeline to capture and store the sensor data was researched. Compression tests were conducted on a calibration machine, with forces ranging from 0 N to 300 N. Local evaluation of sensors' response in different regions was also performed. The three sensors were tested and then compared with the results of a solid silicon pad. One of the capacitive sensors presented an identical response to the solid silicon while the other two either presented poor repeatability or were too stiff, raising concerns for patient comfort. Overall, the proposed system demonstrated its potential to measure and monitor orthosis's applied forces, corroborating its potential for clinical practice.

Orthotic Bracing or Minimally Invasive Surgery? A Summary of 767 Pectus Carinatum Cases for 9 Years

Orthotic bracing and minimally invasive surgery are currently the treatment methods for pectus carinatum. We present our experience with the advantages, method selection criteria, and precautions for both treatment methods. A total of 767 pediatric patients (596 boys and 171 girls) with pectus carinatum were retrospectively analyzed. All of them received orthotic bracing, and 108 pediatric patients received minimally invasive surgery, achieving good outcomes. Among the 767 pediatric patients, 644 obtained satisfactory chest appearance through orthotic bracing, with a success rate of 84.0%. Younger pediatric patients had better orthotic outcomes. Among the 123 failure cases, 108 pediatric patients underwent minimally invasive surgery as the treatment. Seventy-six pediatric patients with simple chondrogladiolar prominence underwent a minimally invasive sternal depression procedure, whereas 32 pediatric patients with complex chondromanubrial prominence underwent surgery. All 108 pediatric patients successfully completed the surgery. The operation time was 112.8 ± 23.5 min, and the average length of hospital stay after the surgery was 7 days. A follow-up was conducted for at least 3 months and up to 3 years. The orthotic effect was satisfactory. For younger pediatric patients with pectus carinatum, noninvasive orthotic bracing treatment should be considered first. For older pediatric patients, the failure rate of the bracing was higher, and the outcomes were often unsatisfactory. Especially for patients over 15 years old, minimally invasive sternal depression may be the preferred treatment for pectus carinatum.

Scoping Review of Healthcare Literature on Mobile, Wearable, and Textile Sensing Technology for Continuous Monitoring

Remote monitoring of health can reduce frequent hospitalisations, diminishing the burden on the healthcare system and cost to the community. Patient monitoring helps identify symptoms associated with diseases or disease-driven disorders, which makes it an essential element of medical diagnoses, clinical interventions, and rehabilitation treatments for severe medical conditions. This monitoring can be expensive and time-consuming and provide an incomplete picture of the state of the patient. In the last decade, there has been a significant increase in the adoption of mobile and wearable devices, along with the introduction of smart textile solutions that offer the possibility of continuous monitoring. These alternatives fuel a technology shift in healthcare, one that involves the continuous tracking and monitoring of individuals. This scoping review examines how mobile, wearable, and textile sensing technology have been permeating healthcare by offering alternate solutions to challenging issues, such as personalised prescriptions or home-based secondary prevention. To do so, we have selected 222 healthcare literature articles published from 2007 to 2019 and reviewed them following the PRISMA process under the schema of a scoping review framework. Overall, our findings show a recent increase in research on mobile sensing technology to address patient monitoring, reflected by 128 articles published in journals and 19 articles in conference proceedings between 2014 and 2019, which represents 57.65% and 8.55% respectively of all included articles.

Outcomes Following Dynamic Compression Bracing for Pectus Carinatum

Introduction: Children with pectus carinatum (PC) are particularly vulnerable to psychosocial effects of poor body image, even though they may not experience physical symptoms. Nonoperative treatment with orthotic bracing is effective in PC correction. We describe our experience with dynamic compression bracing (DCB) for PC patients and their satisfaction with bracing. Materials and Methods: Prospective institutional data of patients undergoing DCB from July 2011 to June 2018 were reviewed and analyzed for those who entered the retainer mode after correction, defined by a correction pressure of <1 psi. A telephone survey was conducted regarding their bracing experience and satisfaction with the outcome on a scale of 1-10. Results: Of 460 PC patients, 144 reached the retainer mode. Median time to retainer mode was 5.5 months. There was no statistically significant relationship between initial correction pressure or carinatum height and time to retainer mode (P = .08 and P = .10, respectively). Fifty-seven percent were compliant with brace use, and median time to retainer mode in this subset was significantly shorter than noncompliant patients (3.5 months versus 10 months, P < .001). Fifty-three percent responded to the survey 13 months [interquartile ratios 3, 33] after the last clinic visit. The main barrier to compliance with wearing the brace was discomfort (37%), while the main motivation for compliance was appearance (58%). All endorsed bracing as worthwhile, with 94% reporting a satisfaction rating of 8 or greater for the correction outcome. Conclusion: DCB is effective in achieving correction of PC in compliant patients. Regardless of time to retainer mode, patients reported high satisfaction with bracing.

A Sensor System to Measure Force Applications of a Brace for Pectus carinatum

Pectus carinatum (PC) presents itself as a protrusion on the chest wall of adolescent individuals. Current treatment for PC is performed with a Pectus carinatum orthosis (PCO) that applies a compressive force to the protrusion. While this treatment is accepted, the magnitude of compressive forces applied remains unknown leading to excessive or deficient compression. Although the need for this quantitative data is recognized, no studies reporting the data or methods are available. The purpose of this study was to design an accurate force measurement system (FMS) that could be incorporated into a PCO with minimal bulk. Components of the FMS were three-dimensional (3D)-printed and incorporated into an existing PCO design. The FMS was calibrated using a custom indenter that applied forces to the FMS in a controlled manner. Evaluation of the FMS on five human participants was also performed. A reliability measure of the FMS was calculated for analysis. The FMS was implemented into the PCO and able to withstand the applied forces. The calibration revealed an increase in load cell error with increased magnitude of applied force (mean error [SD] = 5.59 N [6.48 N]). Participants recruited to evaluate the FMS demonstrated reliable forces (R = 96%) with smaller standard deviations than those during the calibration. The FMS was shown capable of measuring PCO forces but requires further testing and improvement. This system is the foundational component in a wireless, minimalistic sensor system to provide real time force feedback to both the clinician and patient.

Measured dynamic compression for pectus carinatum: A systematic review

BACKGROUND

Patients with pectus carinatum have been treated with orthotic braces since the 1970s. By applying external pressure to the anterior chest wall, a normal chest shape can be restored. However, high patient treatment dropout rates were reported because of the subjectively high pressures applied to the patient´s skin. Measured dynamic compression allows measurement and adjustments of the brace's pressure on the thoracic wall, leading to a controlled correction.

METHODS

We performed an electronic database search (Pubmed and Cochrane) of the medical literature on measured dynamic compression. A total of 14 studies were found and eight studies between 2008 and 2018 were included. Study designs ranged from retrospective chart reviews to cross-sectional cohort studies.

RESULTS

From the 8 studies, 1185 patients were included. The median age was 14 years (range 2-28) and 87% were male. The mean study follow up period was 16 months; 44% of patients were still under treatment, 29% of patients successfully completed treatment. 6% dropped out and 21% were lost to follow-up. Dropout was mainly caused social discomfort (7.2%) and failure of treatment (5.8%). Complications were infrequent. Mild chest discomfort or tightness was reported in 12% and skin lesions occurred in 5.1%. The overall recurrence rate was 2.6%.

CONCLUSIONS

Several studies are available on measured dynamic compression. Dynamic compression appears to be a safe, non-invasive and efficient treatment to correct pectus carinatum in patients with a non-rigid thorax. Patients experience less discomfort, which in turn results in better compliance. However, accurate selection of patients based on age, pressure of initial correction and motivation is important and an objective scoring system to assess the esthetic and long-term physical and psychological results of the treatment is needed.

Bracing of pectus carinatum: A quantitative analysis

BACKGROUND/PURPOSE

Primary treatment of pectus carinatum (PC) is performed with an external brace that compresses the protrusion. Patients are 'prescribed' a brace tightening force. However, no visual guides exist to display this force magnitude. The purpose of this study was to determine the repeatability of patients in applying their prescribed force over time and to determine whether the protrusion stiffness influences the patient-applied forces and the protrusion correction rate.

METHODS

Twenty-one male participants (12-17years) with chondrogladiolar PC were recruited at the time of brace fitting. Participants were evaluated on three visits: fitting, one month postfitting, and two months postfitting. Differences between prescribed force and patient-applied force were evaluated. Relationships of patient-applied force and correction rate with protrusion stiffness were assessed.

RESULTS

Majority of individuals followed for two months (75%) had a significantly different patient-applied force (p<0.05) from their prescribed force. Protrusion stiffness had a positive relationship with patient-applied force, but no relationship with correction rate.

CONCLUSION

Patients did not follow their prescribed force. Magnitudes of these differences require further investigation to determine clinical significance. Patient-applied forces were influenced by protrusion stiffness, but correction rate was not. Other factors may influence these variables, such as patient compliance.

LEVEL OF EVIDENCE

Treatment Study - Level IV.

Success and duration of dynamic bracing for pectus carinatum: A four-year prospective study

BACKGROUND

This study sought to establish factors that can prognosticate outcomes of bracing for pectus carinatum (PC).

METHODS

Prospective data were collected on all patients enrolled in a dynamic bracing protocol from July 2011 to July 2015. Pressure of correction (POC) was measured at initiation of treatment, and pressure of treatment (POT) was measured pre- and post-adjustment at every follow-up visit. Univariate and Cox regression analysis tested the following possible determinants of success and bracing duration: age, sex, symmetry, POC, and POT drop during the first two follow-up visits.

RESULTS

Of 114 patients, 64 (56%) succeeded, 33 (29%) were still in active bracing, and 17 (15%) failed or were lost to follow-up. In successful patients, active and maintenance bracing was 5.66±3.81 and 8.80±3.94months, respectively. Asymmetry and older age were significantly associated with failure. Multivariable Cox proportional hazard analysis of time-to-maintenance showed that asymmetry (p=0.01) and smaller first drop in POT (p=0.02) were associated with longer time to reach maintenance.

CONCLUSIONS

Pressure of correction does not predict failure of bracing, but older age, asymmetry, and smaller first drop in pressure of treatment are associated with failure and longer bracing duration.

LEVEL OF EVIDENCE

Prospective Study/Level of Evidence IV.