The role of 3D printing in chest wall reconstruction.

Technology is advancing fast, and chest wall surgery finds particular benefit in the broader availability of three-dimensional (3D) reconstruction and printing. An increasing number of reports are being published on the use of these resources in virtual 3D reconstructions of chest walls in computed tomography (CT) scans, virtual surgeries, 3D printing of real-size models for surgical planning, practice, and education, and of note, the manufacture of customized 3D printed implants, changing the fundamental conception from a surgery that fits all, to a surgery for each patient. In this review, we explore the evidence published on simple chest wall reconstruction, including the use of 3D technology to assist in the improvement of the repair of the most frequent chest wall deformities: pectus excavatum and carinatum. Current studies are oriented to the automatization and customization of transthoracic implants, as well as education on real-size models. Next, we investigate the implementation of 3D printing in the repair of complex chest wall reconstruction, comprised of infrequent chest wall deformities such as pectus arcuatum and Poland syndrome. These malformations are very heterogeneous resulting in a high degree of improvisation during the surgical repair. In this setting, 3D technology plays a role in the standardization of a process that contemplates customization, concepts that may seem contradictory. Finally, 3D printing with biocompatible materials is rapidly becoming the first choice for the reconstruction of wide chest wall oncological resections. In this work, we review the first and most important current publications on the subject.

Imaging studies in evaluating children with stridor. / Los estudios por imágenes en la evaluación del niño con estridor.

Stridor is a symptom of upper airway obstruction and may result from congenital or acquired causes. The diagnosis is usually clinical. If further investigation is necessary for differential diagnosis, endoscopy is the method of choice in most cases. Imaging studies are complementary to endoscopy. They allow evaluation of laryngeal and tracheobronchial pathology and extrinsic airway compressions due to tumors or vascular malformations and define a lesion's location, extent, and characteristics. They are helpful in cases of diagnostic doubt and when endoscopy is unavailable. It is essential to understand the anatomy and pathophysiology of the respiratory tract and to be aware of the indications and limitations of complementary examinations for proper diagnosis. The different imaging modalities available to evaluate stridor in pediatrics are described, and their advantages are discussed.

El estridor es un síntoma de obstrucción de la vía aérea superior y puede ser resultado de causas congénitas o adquiridas. El diagnóstico suele ser clínico. Si es necesaria una investigación adicional para el diagnóstico diferencial, la endoscopia es el método de elección en la mayoría de los casos. Los estudios por imágenes son complementarios a la endoscopia. Permiten evaluar la patología laríngea y traqueobronquial, las compresiones extrínsecas de la vía aérea por tumores o malformaciones vasculares y definir la localización, extensión y características de una lesión. Son útiles en casos de duda diagnóstica y cuando la endoscopia no está disponible. Es fundamental comprender la anatomía y fisiopatología del tracto respiratorio, y ser conscientes de las indicaciones y limitaciones de los exámenes complementarios para el diagnóstico adecuado. Se describen las diferentes modalidades de imágenes disponibles para evaluar el estridor en pediatría y se discuten sus ventajas.

Unsophisticated assessment of the cardiopulmonary function in patients with pectus excavatum using the six minute walk test.

BACKGROUND: We explored whether the maximum predicted walking distance, assessed with six-minute walk test (6MWT) and reflecting submaximal functional exercise capacity, is decreased among patients with pectus excavatum (PEX). METHODS: This study comprised a retrospective analysis of patients with PEX who underwent a 6MWT for the assessment of functional capacity. The maximum distance walked was recorded and compared to reference values established for different populations, including a young and healthy South American population. RESULTS: We included 43 patients with PEX who underwent 6MWT. The mean age was 17.8 ± 6.7 years. The mean maximum distance walked was significantly lower than the predicted distance (600.8 ± 67.6 metres vs. 729.8 ± 67.5 metres, p < 0.0001). Using the Enright reference equation including an older reference population, the mean negative difference was higher (PEX patients walked 190.4 ± 78.4 metres less than predicted, p < 0.0001). We also applied the Li et al. reference equation accounting for sex among other variables, detecting a decreased walked distance compared to the gender-adjusted predicted distance (PEX patients walked a mean 222.4 ± 87.4 metres less than predicted, p < 0.0001). Using the Ulrich et al. equation, PEX patients walked a mean 114.2 ± 85.1 metres less than predicted (p < 0.0001). Although of uncertain clinical relevance, there was a significant decrease in the mean oxygen saturation after exercise (baseline 97.4 ± 1.2%, vs. final 96.4 ± 2.1%, p = 0.006). CONCLUSIONS: In this study, we identified a significant reduction in the maximum walked distance among patients with PEX compared to the predicted distance, thus potentially emerging as an unsophisticated means to evaluate and quantify functional exercise capacity.

Results of a Novel Long-Term Method for Laparoscopic Skills Online Training.

Introduction: Ensuring patient safety in minimally invasive surgery (MIS) within the field of pediatric surgery requires systematic and extensive practice. Many groups have proposed mastery learning programs encompassing a range of training methods. However, short courses often have a narrow focus on specific objectives, limiting opportunities for sustained training. Our aim was to analyze our results with an online long-term competency-based and supervised training. Methods: This is a retrospective cohort study with prospective data collection of scores and performance of trainees during online courses from October 2020 to April 2023. Results: All participants (n = 76) were able to set up their personal training gym and complete the intensive stage of the course. The total score evolved from 2.60 ± 0.56 at the first meeting to 3.67 ± 0.61 at the fourth meeting, exhibiting a significant difference (P < .013). A considerable drop out was observed in the follow-up stage, with only 53.8% of the participants completing the course. When compared with the first meeting, they also showed a significant improvement with a mean general score of 3.85 ± 0.25 (P < .013) Conclusion: We have presented a novel online training program, based on continuous training that demonstrated that the unlimited access to a personal training gym allows surgeons to improve and maintain MIS skills.

Lessons Learned after 176 Patients Treated with a Standardized Procedure of Thoracoscopic Cryoanalgesia during Minimally Invasive Repair of Pectus Excavatum.

BACKGROUND: Intrathoracic intercostal cryoanalgesia (Cryo) during minimally invasive repair of pectus excavatum (MIRPE) reports have been related to improved pain management, although its extent differs amongst studies. We aimed to report our experience using a standardized perioperative approach including Cryo during MIRPE, and compare our actual results with those of a previous thoracic epidural analgesia (TE) cohort. Lessons learned are summarized. METHODS: Retrospective study including patients undergoing Cryo during MIRPE between October 2018 and May 2023. Results with a standardized perioperative approach were analyzed. We then compared our Cryo cohort with a previous cohort of 62 patients who underwent TE and MIRPE between 2013 and 2018. Continuous variables were reported as mean and standard deviation, and as median (interquartile range) for variables with non-uniform distribution. RESULTS: We performed 176 Cryo during MIRPE (16.8 ± 4.6 years), with a mean postoperative length of stay (LOS) of 1.4 ± 0.8 days and a median total requirement of 7.5 (0.0; 15.0) oral morphine equivalents (OME) (mg). Patients with Cryo had a significantly lower mean LOS (1.4 ± 0.8 vs. 3.6 ± 1.0 days, p < 0.0001), and median total opioid requirement [7.5 (0.0; 15.0) vs. 77.4 (27.0; 115.5 OME (mg), p < 0.0001) compared to TE patients. Lessons learned included ensuring adequate contact of the cryoprobe with the target, proper exposition, and specialized multidisciplinary perioperative patient and family support, including psychology and physical therapy. CONCLUSIONS: In this study, we reported lessons learned after performing a standardized protocol of perioperative care in patients undergoing Cryo during MIRPE. This protocol enabled the achievement of a short LOS and low postoperative opioid requirement. TYPE OF STUDY: Retrospective comparative study. LEVEL OF EVIDENCE: III.

Advantages of FDM and gamma irradiation to manufacture personalized medical devices for airway obstructions.

In the early childhood population, congenital airway conditions like bronchomalacia (BM) can pose a life-threatening threat. A breakthrough technology called additive manufacturing, or 3D printing, makes it feasible to create a biomedical device that aids in the treatment of airway obstruction. This article describes how a polycaprolactone (PCL) splint for the upper airways can be created using the fusion deposition technique (FDM) and sterilized using gamma radiation. It is presented as a simple, accessible, and cost-reduced alternative that complements other techniques using more expensive and sophisticated printing methods. Thermomechanical and morphological analysis proved that FDM and sterilizing by gamma irradiation are both appropriate methods for producing splints to treat life-threatening airway blockages. Additionally, the 3D-printed splints' effectiveness in treating a young patient with BM that was life-threatening was assessed by medical professionals. In this regard, the case report of a patient with 34 months of follow-up is presented. Splints manufactured by this affordable 3D printing method successfully surpass breathing arrest in life-threatening airway obstruction in pediatric patients. The success of this procedure represents a fundamental contribution to the treatment of the population in countries where access to expensive and complex technologies is not available.

Novel index to estimate the cephalocaudal extent of the excavation in pectus excavatum: The Titanic index.

BACKGROUND/PURPOSE: Quantification of the severity of pectus excavatum deformities is currently performed using the Haller index (HI) and the Correction index (CI), amongst others. However, most indexes characterize the severity at the point of maximum excavation. We present a new index, the Titanic index (TI), aimed at the appraisal of the cephalocaudal extent of the excavation and its potential clinical use. MATERIALS AND METHODS: Retrospective analysis of a cohort of patients who underwent a minimally invasive repair of pectus excavatum (MIRPE) between July 2020 and April 2022 at a single center. We defined TI as the percentage of the sternum that lied behind the anterior costal line observed in the CT. Demographics, HI, CI, and TI calculated based on computed tomography images (CT) were analyzed. Also, we compared the severity indexes of two groups of patients divided by the number of implants introduced per patient (group A: two implants, and group B: more than two). RESULTS: Seventy-eight patients (92% male) were included, with a mean age of 17.2 ± 4.8 years. The mean TI was 37%. Albeit weak, we identified significant correlations between the TI and the HI and, more closely, to the CI. Two implants were introduced in 37 (47%) patients, and more than two in 41 (53%) patients. Compared to patients with two implants, the group of patients who received more than two implants were older and showed worse thoracic indexes. Using receiver operating characteristic curve analysis, we identified the TI as a better predictor of the need for more than two implants than HI and CI. In this regard, a TI larger than 66.5% had a sensitivity of 93% and a specificity of 92%. CONCLUSION: We propose a novel index for the categorization of the severity of pectus excavatum. This index might be useful in planning the number of implants required for complete thoracic remodeling during MIRPE. LEVEL OF EVIDENCE: Level III. TYPE OF STUDY: Retrospective Comparative Study.

Determinants of success associated with vacuum bell treatment of pectus excavatum.

BACKGROUND/PURPOSE: We explored determinants of success in a large cohort of patients with pectus excavatum submitted to vacuum bell treatment and compared groups with satisfactory versus unsatisfactory outcomes. METHODS: Retrospective case-control study in a single center between May 2013 and January 2020, including patients with pectus excavatum treated with vacuum bell. We classified patients according to their status at closure of data registry (surveillance; withdrawal; complete correction; failure) and according to Obermeyer's classification of degrees of pectus excavatum correction. Determinants of success were calculated using receiver operating characteristic curves. RESULTS: Overall, 186 patients were included. Complete correction was achieved by 17% of the cases, while 45% remained under surveillance. Failure rates were low (n = 9; 5%), whereas withdrawal rates were 34%. Based on Obermeyer's classification of degree of excavation correction, 35% had excellent/good, 25% fair, and 40% poor/worse results. When comparing patients with good/excellent results with those with unsatisfactory results, patients with good/excellent results had a longer treatment duration [19.0 (13.0; 28) months vs. 13.0 (6.5; 22.5) months, p<0.0001], and lower initial pectus depth [1.6 (1.2; 2.0) cm, vs. 2.0 (1.5; 2.6) cm, p = 0.001]. Using ROC curves, the best determinants of success were an initial pectus depth ≤ 1.8 cm and a length of treatment > 12 months. CONCLUSION: One-third of patients in treatment with a vacuum bell achieved excellent or good outcomes in our cohort. Determinants of success included an initial pectus depth of 1.8 cm or less and a minimum length of treatment of 12 months. TYPE OF STUDY: retrospective comparative study LEVEL OF EVIDENCE: III.

Usefulness of strain cardiac magnetic resonance for the exposure of mild left ventricular systolic abnormalities in pectus excavatum.

BACKGROUND: Systolic dysfunction in pectus excavatum (PEX) is usually very subtle and mainly focused on the right ventricle (RV), leading to normal or unremarkable cardiac imaging findings unless involving exercise stress. OBJECTIVES: We evaluated systolic function in PEX using longitudinal strain cardiac magnetic resonance (CMR), a validated parameter for the assessment of the systolic deformation of subendocardial fibers. METHODS: This prospective registry comprised consecutive patients with PEX who were referred to CMR to define treatment strategies or to establish surgical candidacy. We also included a control group of 15 healthy volunteers without chest wall abnormalities. Using dedicated software, we evaluated the endocardial global longitudinal strain (GLS) of both ventricles and the endocardial global circumferential strain (GCS) of the left ventricle (LV). RESULTS: A total of 50 patients with PEX comprised the study population, with a mean age of 19.9 ± 8.0 years. The right ventricular ejection fraction (RVEF) of patients with PEX was significantly lower compared to the control group both at end-expiration (59.5 ± 6.8 vs. 64.7 ± 4.7%, p = 0.008) and end-inspiration (56.7 ± 7.2%, vs. 62.7 ± 4.4, p = 0.004); as well as the pulmonary stroke distance (12.6 ± 2.5, vs. 15.0 ± 2.0 cm, p = 0.001). The LV volumetric analysis revealed no differences between PEX and the control group (p > 0.05 for all) regardless of the respiratory cycle, with a mean expiratory LV ejection fraction (LVEF) of 61.4 ± 6.0%. In contrast, the GLS of the LV was significantly lower in PEX compared to controls (-21.2 ± 3.2 vs. -23.7 ± 3.0%, p = 0.010), whereas GCS was similar either at expiration (-28.5 ± 4.0%, vs. -29.5 ± 2.8, p = 0.38) or inspiration (-29.3 ± 4.1%, vs.-28.9 ± 2.3, p = 0.73). CONCLUSIONS: In this study, we demonstrated that longitudinal strain analysis might enable the detection of very subtle left ventricular systolic function abnormalities in patients with PEX, that are commonly overlooked using the conventional assessment. LEVEL OF EVIDENCE: II.

Remote treatment of pectus carinatum (Telepectus) during the COVID-19 pandemic.

BACKGROUND/PURPOSE: To report telemedicine's feasibility and satisfaction rates for treating patients with pectus carinatum using a dynamic compressor system. We analyzed treatment adherence in comparison with the previous, non-pandemic year. MATERIALS AND METHODS: Retrospective analysis including patients with pectus carinatum under treatment with a dynamic compressor system using telemedicine at the chest wall centers from two hospitals, private and public, between April and July 2020. A free video conference platform for teleconsultations was employed. We evaluated the incidence of pectus cases with telemedicine, the number of dynamic compressor system prescriptions, the number of patients in the correction phase, and the number who ended treatment. To assess adherence, we compared our cohort with an in-person cohort during the same time frame of the previous, non-pandemic year. In addition, we performed a patient satisfaction survey comprising questions related to socioeconomic status, the likeability of telemedicine, simplicity of modification of the system, and desire to continue with telepectus after the pandemic. RESULTS: One hundred and thirty-six telepectus consultations were performed in 76 patients. During this time frame, 15 patients started using the dynamic compressor system. Compared to the previous, non-pandemic year, the number of consultations per patient was similar (2019: 1.92 ± 1 .0 vs. 2020: 1.79 ± 0.8, p = 0.32), and there was a significant reduction in the number of dropouts with the use of telemedicine (9% vs. 1%, p = 0.025). Fifty-nine patients answered the satisfaction survey. All of them solved their doubts through telemedicine. Overall, 95% found telemedicine comfortable. Of note, those with a lower income evidenced the highest intention in continuing with telemedicine. CONCLUSIONS: We demonstrated the feasibility of remote care of patients with pectus carinatum using a dynamic compressor system with a similar frequency of consultations compared to in-person medical care. Telepectus patients revealed a high rate of satisfaction irrespective of their socioeconomic status. LEVEL OF EVIDENCE: IV. TYPE OF STUDY: Retrospective study.

Decanulación traqueal en pediatría: ¿cuándo y cómo? / Tracheal decannulation in pediatrics: When and how?

La decanulación es el proceso de retirar la cánula de traqueotomía de forma definitiva, una vez que la patología original que motivó la traqueotomía se haya resuelto o mejorado significativamente.La predicción del éxito de decanulación es difícil debido a la influencia de varios factores. No existe un protocolo universalmente aceptado. Existen diversos protocolos y la elección depende, en gran medida, de cada institución y de la situación individual de cada paciente. Sin embargo, para lograr la decanulación exitosa deben tenerse en cuenta varios criterios esenciales que deben cumplirse independientemente del protocolo elegido.Se señalan las características que debe reunir el paciente apto para la decanulación y se presentan recomendaciones sobre los pasos necesarios para lograr el retiro de la cánula de traqueotomía en el niño de manera segura y minimizando el riesgo de fracaso.

Decannulation is the process of removing the tracheotomy cannula permanently, once the original pathology that led to the tracheotomy has been resolved or significantly improved. The prediction of decannulation success is difficult due to the influence of several factors. There is no universally accepted decannulation protocol. There are several protocols and the choice depends, largely, on each institution and the individual situation of each patient. However, in order to achieve successful decannulation, several essential criteria must be taken into account, which must be fulfilled regardless of the chosen protocol.We indicate the characteristics that the patient must meet for decannulation, and we present recommendations on the necessary steps to achieve the removal of the tracheotomy cannula in a child safely and minimizing the risk of failure.

[Tracheal decannulation in pediatrics: When and how?] / Decanulación traqueal en pediatría: ¿cuándo y cómo?

Decannulation is the process of removing the tracheotomy cannula permanently, once the original pathology that led to the tracheotomy has been resolved or significantly improved. The prediction of decannulation success is difficult due to the influence of several factors. There is no universally accepted decannulation protocol. There are several protocols and the choice depends, largely, on each institution and the individual situation of each patient. However, in order to achieve successful decannulation, several essential criteria must be taken into account, which must be fulfilled regardless of the chosen protocol. We indicate the characteristics that the patient must meet for decannulation, and we present recommendations on the necessary steps to achieve the removal of the tracheotomy cannula in a child safely and minimizing the risk of failure.

La decanulación es el proceso de retirar la cánula de traqueotomía de forma definitiva, una vez que la patología original que motivó la traqueotomía se haya resuelto o mejorado significativamente. La predicción del éxito de decanulación es difícil debido a la influencia de varios factores. No existe un protocolo universalmente aceptado. Existen diversos protocolos y la elección depende, en gran medida, de cada institución y de la situación individual de cada paciente. Sin embargo, para lograr la decanulación exitosa deben tenerse en cuenta varios criterios esenciales que deben cumplirse independientemente del protocolo elegido. Se señalan las características que debe reunir el paciente apto para la decanulación y se presentan recomendaciones sobre los pasos necesarios para lograr el retiro de la cánula de traqueotomía en el niño de manera segura y minimizando el riesgo de fracaso.

Resorbable airway splint, stents, and 3D reconstruction and printing of the airway in tracheobronchomalacia.

Tracheobronchomalacia (TBM) is the most common tracheobronchial obstruction. Most cases are mild to moderate; therefore, they do not need surgical treatment. Severe tracheomalacia, however, represents a diagnostic and therapeutic challenge since they are very heterogeneous. In the armamentarium of resources for the treatment of dynamic airway collapse, splints and stents are two underused strategies and yet, they may represent the best alternative in selected cases. Lately, computed tomography 3D reconstruction of the airway has been used for the design of virtual models that can be 3D-printed for the creation of novel devices to address training, simulation, and biotechnological implants for refractory and severe airway malformations. This manuscript examines the role of resorbable stents, splints, and the 3D reconstruction and printing of the pediatric airway in tracheobronchomalacia.

Implementation and acceptance rates of a specially designed vacuometer for the vacuum bell treatment of pectus excavatum.

BACKGROUND / PURPOSE: To report the implementation of a specially designed vacuometer for the ambulatory measurement of the exact negative pressure self-applied by the patient when using the vacuum bell for the treatment of pectus excavatum and to analyze patient satisfaction with the device, by conducting a survey. METHODS: Between October 2018 and June 2020, all patients with pectus excavatum who received a vacuum bell at our Pectus Clinic were provided with a specially designed pectus vacuometer for their personal use. We described the vacuometer, the fundamentals of its development, and the utilization protocol. A survey was conducted evaluating comfort, clarity of instructions, usefulness, simplicity of connection, and likeability. The level of satisfaction was assessed using a Likert scale ranging from 1 (very negative experience) to 5 (very positive experience). The occurrence of skin lesions provoked by the application of the vacuum bell was registered. RESULTS: From 72 submitted surveys, 54 patients answered. Patient demographics comprised 44 (81.5%) males and a mean age of 12.6 ± 6.0 years. The mean initial external pectus depth was 2.0 ± 0.7 cm and the mean duration of treatment was 13.2 ± 8.6 months. No skin lesions were detected while using the vacuum bell and the vacuometer. The mean general satisfaction score was 4.4 ± 0.7 and 83.3% of the respondents did not have any inconvenience with the vacuometer. A patient who considered himself cured was the only dropout during the study. CONCLUSIONS: In this study, we described the feasibility and fundamentals of the application of a specifically designed vacuometer for ambulatory use as an adjunct to the treatment of pectus excavatum with a vacuum bell, and demonstrated a high satisfaction level with the device. In addition, the vacuometer might help avoid skin lesions secondary to the vacuum bell and foster adhesion to treatment. TYPE OF STUDY: Treatment study. LEVEL OF EVIDENCE: IV.

Surgical Planning, Simulation, and Prosthesis Customization for Complex Chest Wall Malformations.

Despite the emergent application of 3-dimensional technology for thoracic reconstructions, reports regarding its use for the resolution of the heterogeneous subgroup of complex chest wall malformations are lacking. We aim to report a novel, standardized process of personalized repair of complex chest wall malformations comprising multidisciplinary, comprehensive surgical planning; surgical simulation on a 3-dimensionally printed scale model of the area of interest; manufacturing of customized prostheses; and surgical repair according to plan. We propose this therapeutic strategy for the resolution of such a wide variety of chest wall deformities to reduce improvisation and enhance outcomes.

From bench to bedside: 3D reconstruction and printing as a valuable tool for the chest wall surgeon.

BACKGROUND/PURPOSE: The development of computer-aided design/manufacturing and digital image technology shows promise to revolutionize several medical and surgical fields. In this context, we propose a different approach for minimally invasive repair of pectus excavatum (MIRPE) including preoperative planning, ambulatory template fitting, and implant customization. METHODS: We prospectively collected data on 130 consecutive patients who underwent a novel process of implant customization for MIRPE between November 2015 and September 2019 at our institution. This process consisted of: 1) preoperative planning using 3D computed tomography scan reconstruction and 3D printing of the implant template, 2) an ambulatory fitting session with the template, and 3) manufacture of a custom made, prebent, metallic implant based on the 3D printed templates. We described the process in detail and analyzed the "implant-deformity" match, need for rebending, modification of the curvature or shape of the pectus implant intraoperatively, and accuracy of the number of bars planned preoperatively. RESULTS: Preoperative planning including 3D reconstruction and printing resulted in a 92.3% optimal "implant-deformity" anatomic match. Minimal rebending without flipping of the implants was required in 5.4% of the patients. In two cases (1.5%), the implants were too short, and they tended to sink into the intercostal space, and in one case (0.8%), the patient's chest was extremely asymmetric, and the implant had to be removed and rebent intraoperatively. The number of implants planned preoperatively was precise in 100%. CONCLUSIONS: In this study, we demonstrated that minimally invasive repair of pectus excavatum assisted by preoperative planning, ambulatory template fitting, and implant customization enables an excellent anatomic match, leading to minimal rebending, and avoiding implant flipping or removal after retrosternal passage as well as accuracy in the number of bars programmed preoperatively. TYPE OF STUDY: Prospective registry. LEVEL OF EVIDENCE: III.

Safety-string: A handy maneuver to control pectus bar removal bleeding complications.

The pectus bar removal procedure is often considered a simple, straightforward surgery with a low incidence of complications. However, life-threatening bleeding complications have been reported requiring major measures for hemostatic control. Our objective is to share a simple maneuver that our group has systematically included in the bar removal procedure to facilitate bleeding control in case hemorrhage occurs.