Further experience with polydioxanone airway stents in children.

INTRODUCTION: The aims of this study were to update our experience with biodegradable polydioxanone (PDO) airway stents in children, focusing on effectiveness and safety, and to analyze the factors involved in the different outcomes observed. MATERIALS AND METHODS: Retrospective study of patients managed with PDO stents from 2012 to 2023. Variables collected: demographics, comorbidities, indication, clinical baseline, stent size, location, complications, clinical outcome, and time of follow-up. Statistical analyses were performed to detect the eventual contribution of variables in the different outcomes observed. RESULTS: Fifty-four PDO stents were placed in 26 patients (median age, 4 months). All showed severe symptoms of central airway obstruction due to tracheomalacia in nine patients, bronchomalacia five, tracheobronchomalacia 10, and tracheal stenosis two. Stent placement was uneventful in every case: 29 stents in the trachea and 25 in the main bronchi. 53.8% of patients needed successive stenting, and all exhibited comorbidities. Complete clinical resolution was observed in eight cases (30.7%), partial improvement in 13 (50%), unchanged in 4 (15.3%), and worsened in one. Age had a significant positive impact on outcome (6 vs. 3 months; p = 0.024). Additionally, smaller stents were associated with a better outcome (20 vs. 26 mm; p = 0.044). Granulation tissue was the most frequent complication (34.6%). Five patients (19.2%) died due to severe comorbidities, follow-up was complete in survivors (median, 58 months). CONCLUSIONS: PDO stents are safe and effective when dealing with severe tracheobronchial obstruction. Stent-related granulation tissue continues to be a relevant matter of concern. This issue, together with increased degradation times, deserves further research.

Biodegradable polydioxanone stents: histologic and structural effects in an experimental model of tracheal stenosis.

OBJECTIVES: To evaluate the biologic impact of polydioxanone (PDO) stenting in an animal model of inflammatory tracheal stenosis (TS). Additionally, to compare these results with those obtained in the same model without a stent and after placing one PDO stent in a healthy trachea. METHODS: 40 adult NZ rabbits were distributed into 3 groups: Group A, 8 animals with a healthy trachea and a PDO stent; group B, 17 rabbits with a TS and no stent; and group C, 15 animals with TS and a PDO stent. Histopathological studies included Masson's trichrome staining for submucosal fibrosis and Safranin O to assess structural integrity of cartilage. Morphometric analyses were performed in the 3 groups. RESULTS: Stent placement was successful in every case. Histological studies did not show a significant increase in tracheal wall collagen area and cartilage structure was not modified in those rabbits with a PDO stent, even in a TS scenario. Stent implantation permitted recovery of normal tracheal lumen levels in the TS model. CONCLUSIONS: PDO stenting in the normal trachea and in a model of TS neither caused increase in the collagen matrix nor modification of the cartilaginous support. Additionally, radial force exhibited by PDO stents was effective in restoring normal tracheal lumen when placed in a stenotic lesion. These findings suggest that they may be safe and useful in the setting of an acquired TS.

Concordancia entre el diagnóstico por imagen y la histología en las malformaciones pulmonares congénitas / Diagnostic accuracy of imaging compared to histology in congenital lung malformations

Introducción: El objetivo fue evaluar la concordancia entre las pruebas de imagen, la ecografía prenatal y la TC posnatal empleadas en el diagnóstico de malformaciones pulmonares congénitas (MPC) y el estudio anatomopatológico (AP).Material y métodos: Estudio retrospectivo de pacientes diagnosticados prenatalmente de MPC en los que se realizó seguimiento posnatal incluyendo una TC y un estudio AP de la lesión. Las variables estudiadas incluyeron: datos demográficos, edad gestacional al diagnóstico, hallazgos ecográficos y existencia de gestación múltiple. Utilizamos el coeficiente estadístico Kappa para establecer la concordancia entre la ecografía y las pruebas postnatales (TC y AP). Se analizaron de forma pareada la presencia de lesiones, la localización, el tipo y el tamaño, y la presencia de vascularización sistémica.Resultados: Se incluyeron 56 pacientes con 57 lesiones. La edad gestacional media al diagnóstico fue 22,42±3,94 semanas y el 57% fueron varones. El pulmón izquierdo y los lóbulos inferiores fueron los más afectados. La concordancia entre TC y AP en la detección de lesiones quísticas fue moderada (Kappa=0,55) pero más relevante que la detectada entre ecografía y AP (Kappa=0,10), siendo discreta entre ambas pruebas de imagen. La concordancia TC/AP fue sustancial (Kappa=0,66) en la detección de vascularización sistémica de la lesión y superior a la determinada entre ecografía y AP. Ambas pruebas de imagen demostraron una precisión muy buena en la identificación de la localización de las lesiones.Conclusiones: La TC posnatal ofrece una concordancia sustancial con el estudio histológico, especialmente en la detección de vascularización, y nos aporta datos predecibles sobre la anatomía de la lesión.(AU)

Introduction: The aim of this study was to evaluate the accuracy of imaging tests (prenatal ultrasound [US] and postnatal computed tomography [CT]) in comparison to histology for diagnosis of congenital lung malformations (CLMs).Material and methods: Retrospective study of patients with a prenatal diagnosis of CLM whose postnatal followup included thoracic CT scan and histological examination of the lesion. We collected data on demographic variables, gestational age at diagnosis, US findings and the history of multiple gestation. We used the kappa coefficient to determine the level of agreement between the findings of prenatal US and postnatal tests (CT and histology). We analysed paired data on the size of the lesion, its location and the presence or absence of systemic arterial vascularization.Results: The sample included 56 patients with 57 lesions. The mean gestational age at diagnosis was 22.42 weeks (SD, 3.94) and 57% were male. Malformations most frequently involved the left lung and the lower lobes. The agreement between CT and histology in the detection of cystic lesions was moderate (κ=.55) but stronger compared to the agreement between US and histology (κ=.10). The agreement between CT and histology was substantial (κ=.66) in the detection of systemic vascularization of the lesion and stronger compared to the agreement between US and histology. Both imaging methods were highly accurate in the identification of the location of the pulmonary lesions.Conclusions: Postnatal CT offers a substantial concordance with histological findings, especially in the detection of systemic vascularization, and an accurate prediction of the anatomy of the lesion.(AU)

Diagnostic accuracy of imaging compared to histology in congenital lung malformations.

INTRODUCTION: The aim of this study was to evaluate the accuracy of imaging tests (prenatal ultrasound [US] and postnatal computed tomography [CT]) in comparison to histology for diagnosis of congenital lung malformations (CLMs). MATERIAL AND METHODS: Retrospective study of patients with a prenatal diagnosis of CLM whose postnatal follow-up included thoracic CT scan and histological examination of the lesion. We collected data on demographic variables, gestational age at diagnosis, US findings and the history of multiple gestation. We used the kappa coefficient to determine the level of agreement between the findings of prenatal US and postnatal tests (CT and histology).We analysed paired data on the size of the lesion, its location and the presence or absence of systemic arterial vascularization. RESULTS: The sample included 56 patients with 57 lesions. The mean gestational age at diagnosis was 22.42 weeks (SD, 3.94) and 57% were male. Malformations most frequently involved the left lung and the lower lobes. The agreement between CT and histology in the detection of cystic lesions was moderate (κ = 0.55) but stronger compared to the agreement between US and histology (κ = 0.10). The agreement between CT and histology was substantial (κ = 0.66) in the detection of systemic vascularization of the lesion and stronger compared to the agreement between US and histology. Both imaging methods were highly accurate in the identification of the location of the pulmonary lesions. CONCLUSIONS: postnatal CT offers a substantial concordance with histological findings, especially in the detection of systemic vascularization, and an accurate prediction of the anatomy of the lesion.

Histological and structural effects of biodegradable polydioxanone stents in the rabbit trachea.

OBJECTIVES: The aim of this study was to evaluate the potential biologic effects caused by the successive placement of biodegradable polydioxanone (PDO) stents in the rabbit trachea. PDO stents could eventually induce a fibroproliferative reaction in the submucosa that could be beneficial in the treatment of malacia due to an increase in its consistency without impairing the tracheal lumen. METHODS: Sixteen adult NZ rabbits were distributed into 3 groups with different survival times according to the number of stents placed: 1 stent (14 weeks), 2 stents (28 weeks) and 3 stents (42 weeks). Stent insertion was performed endoscopically in the cervical trachea of the animal. Histopathological studies included Masson's trichrome staining for submucosal fibrosis and Safranin O to assess the structural integrity of cartilage. Potential inflammatory changes were analysed by means of immunohistochemistry determining the number of CD45-positive cells. RESULTS: Stent placement was successful in every case. Histological studies did not show a statistically significant increase in tracheal wall collagen area and cartilage structure was not modified in those rabbits with 1 or more PDO stents inserted compared to non-stented tracheal sections. Furthermore, no statistically significant changes in the number of CD45+ cells were observed in stented tracheal segments compared to normal tracheal tissues. CONCLUSIONS: According to our data, successive PDO stenting caused mild inflammatory changes in the tracheal wall and no increase in the collagen matrix, and the cartilaginous support was not modified during a long follow-up period (up to 42 weeks). These findings suggest that they may be safe and show good biocompatibility in the long term.

Malformación linfática mesentérica: una causa poco frecuente de abdomen agudo / Mesenteric lymphatic malformation: A rare cause of an acute abdomen

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Vocal cord paralysis after cardiovascular surgery in children: incidence, risk factors and diagnostic options.

OBJECTIVES: The aim of this study was to assess the incidence of vocal cord paralysis (VCP) in children after cardiovascular surgery. The secondary aims were to identify the factors potentially associated with VCP and to assess the diagnostic utility of laryngeal ultrasound (US). METHODS: This study is a retrospective review of patients who underwent aortic repair, patent ductus arteriosus ligation and left pulmonary artery surgeries from 2007 to 2017. The following data were collected: patient demographics, gestational age, weight and age at surgery, comorbidities, cardiovascular anomaly and type of procedure, laryngoscopic and US evaluation results. Univariable and multivariable logistic regression models were used to identify the variables associated with VCP. RESULTS: Two hundred and six patients were included in the study. Seventy-two patients (35%) were preterm and 32.5% showed comorbidities. At surgery, median age and weight were 0.6 months [interquartile range (IQR) 0.3-2.1] and 3.0 kg (IQR 1.3-4.0), respectively. Postoperatively, symptomatic patients underwent endoscopic evaluation and VCP was detected in 25 cases (12.1%). Laryngeal US was performed in 8 of these showing an excellent diagnostic relationship. On univariable analysis, factors significantly associated with VCP were prematurity, young age and lower weight at surgery and the presence of comorbidities. The presence of comorbidities and weight at surgery exhibited a significant risk of developing VCP postoperatively on multivariable analysis. CONCLUSIONS: VCP is not an unusual complication of cardiovascular surgery. Certain factors were associated with VCP development but only the presence of comorbidities and weight at surgery were statistically significant on multivariable analysis. Flexible laryngoscopy is the standard diagnostic technique and laryngeal US appears to be a reliable complement.

[How do renal function and dilation change after pieloplasty surgery in children?] / ¿Cómo varía la función y dilatación renal después de la cirugía de pieloplastia en edad pediátrica?

OBJECTIVE: The effects of pyeloplasty on renal function are not fully well defined. Our objective is to determine if renal function and renal dilation change after pyeloplasty and the risk factors that may influence in both parameters. METHODS: Retrospective study of patients who underwent pyeloplasty. The parameters analyzed included: age, differential renal function, renal dilation, infection and complications. We compared ultrasound findings with measurement of the anterior-posterior diameter of the renal pelvis (mm) and the time/activity upload curve of the 99mTc- Mercaptoacetyltriglycine renography before and after surgery. Patients were divided in groups by renal function: bad (<20%), diminished (20-40%), normal (40-55%) and supranormal (>55%). RESULTS: A total of 129 patients were included in the study. The normal renal function group was the one undergoing surgery most frequently. Comparison of function before and after surgery showed a statistically significant improvement when preoperative function was bad (<20%) (mean 9.2+/-8.9) or supranormal (>55%) (mean -8.7+/-8.5). In the subgroup of patients under 12 months, it was notable there were significant results only when renal function was diminished (20-40%) (mean 5.6+/-2.2). Renal dilation presented significant changes after surgery in all groups (mean 5.6+/-2.2) (p<0.0001), except in cases presenting complications. CONCLUSIONS: Previous renal function has prognostic value on pieloplasty results. Supranormal renal function should be considered pathologic, but recoverable and it may improve after pieloplasty. In the absence of intra or postoperative complications, pyelocalycial dilation diminished after pieloplasty.

OBJETIVO: Los efectos de la pieloplastia sobre la función renal no están totalmente definidos. Nuestro objetivo es determinar si cambia la función renal y la dilatación renal después de la cirugía de pieloplastia y los factores que pueden influir en ambos parámetros.MÉTODOS: Estudio retrospectivo de pacientes intervenidos de pieloplastia. Se analizaron los parámetros: edad, función renal diferencial, dilatación renal, infección y complicaciones. Se compararon los hallazgos en la ecografía con la medición del diámetro anteroposterior de la pelvis (mm) y la curva de captación tiempo/ actividad en el renograma 99m Tc- Mercaptoacetiltriglicina antes y después de la cirugía. Dividimos a los pacientes en función mala (<20%), regular (20-40%), normal (40-55%) y supranormal (>55%). RESULTADOS: Se incluyeron un total de 129 pacientes, el grupo de pacientes intervenidos más frecuentemente fueron aquéllos que presentaban una función renal normal (40-55%). Al comparar la función antes y después de la cirugía, se observó una mejoría estadísticamente significativa cuando la función preoperatoria es mala <20% (media 9,2 +/-8,9) o cuando es supranormal >55% (media -8,7+/-8,5). En el subgrupo de pacientes menores de 12 meses destacó que sólo hubo resultados significativos cuando la función era regular 20-40% (media 5,6+/-2,2). La dilatación renal presentó cambios significativos (p<0,0001) tras la cirugía en todos los grupos de pacientes (media -12,4 +/-1,2), excepto cuando se habían producido complicaciones. CONCLUSIONES: La función renal previa tuvo valor pronóstico en cuanto a resultados de la pieloplastia. La función supranormal debe considerarse patológica, pero recuperable y puede mejorar tras pieloplastia. En ausencia de incidencias intra o postoperatorias, la dilatación pielocalicial disminuyó tras la pieloplastia.

¿Cómo varía la función y dilatación renal después de la cirugía de pieloplastia en edad pediátrica? / How do renal function and dilation change after pieloplasty surgery in children?

Objetivo: Los efectos de la pieloplastia sobre la función renal no están totalmente definidos. Nuestro objetivo es determinar si cambia la función renal y la dilatación renal después de la cirugía de pieloplastia y los factores que pueden influir en ambos parámetros. Métodos: Estudio retrospectivo de pacientes intervenidos de pieloplastia. Se analizaron los parámetros: edad, función renal diferencial, dilatación renal, infección y complicaciones. Se compararon los hallazgos en la ecografía con la medición del diámetro anteroposterior de la pelvis (mm) y la curva de captación tiempo/ actividad en el renograma 99m Tc- Mercaptoacetiltriglicina antes y después de la cirugía. Dividimos a los pacientes en función mala (< 20%), regular (20-40%), normal (40-55%) y supranormal (> 55%). Resultados: Se incluyeron un total de 129 pacientes, el grupo de pacientes intervenidos más frecuentemente fueron aquéllos que presentaban una función renal normal (40-55%). Al comparar la función antes y después de la cirugía, se observó una mejoría estadísticamente significativa cuando la función preoperatoria es mala < 20% (media 9,2 +/-8,9) o cuando es supranormal > 55% (media -8,7 +/- 8,5). En el subgrupo de pacientes menores de 12 meses destacó que sólo hubo resultados significativos cuando la función era regular 20-40% (media 5,6 +/- 2,2). La dilatación renal presentó cambios significativos (p < 0,0001) tras la cirugía en todos los grupos de pacientes (media -12,4 +/- 1,2), excepto cuando se habían producido complicaciones. Conclusiones: La función renal previa tuvo valor pronóstico en cuanto a resultados de la pieloplastia. La función supranormal debe considerarse patológica, pero recuperable y puede mejorar tras pieloplastia. En ausencia de incidencias intra o postoperatorias, la dilatación pielocalicial disminuyó tras la pieloplastia

Objective: The effects of pyeloplasty on renal function are not fully well defined. Our objective is to determine if renal function and renal dilation change after pyeloplasty and the risk factors that may influence in both parameters. Methods: Retrospective study of patients who underwent pyeloplasty. The parameters analyzed included: age, differential renal function, renal dilation, infection and complications. We compared ultrasound findings with measurement of the anterior-posterior diameter of the renal pelvis (mm) and the time/activity upload curve of the 99mTc- Mercaptoacetyltriglycine renography before and after surgery. Patients were divided in groups by renal function: bad (< 20%), diminished (20-40%), normal (40-55%) and supranormal (> 55%). Results: A total of 129 patients were included in the study. The normal renal function group was the one undergoing surgery most frequently. Comparison of function before and after surgery showed a statistically significant improvement when preoperative function was bad (< 20%) (mean 9.2 +/- 8.9) or supranormal (> 55%) (mean -8.7 +/- 8.5). In the subgroup of patients under 12 months, it was notable there were significant results only when renal function was diminished (20-40%) (mean 5.6 +/- 2.2). Renal dilation presented significant changes after surgery in all groups (mean 5.6 +/- 2.2) (p < 0.0001), except in cases presenting complications. Conclusions: Previous renal function has prognostic value on pieloplasty results. Supranormal renal function should be considered pathologic, but recoverable and it may improve after pieloplasty. In the absence of intra or postoperative complications, pyelocalycial dilation diminished after pieloplasty