Lung function evaluation through computerized tomography and 3D reconstruction of airways: a body mass index pilot study / Evaluación de la función pulmonar mediante tomografía computarizada y reconstrucción 3D de las vías respiratorias: estudio piloto del índice de masa corporal

SUMMARY: Obesity is a worldwide epidemic that has become a risk factor for the development of respiratory problems, meaning it is necessary to generate models that assess lung function in obese patients for proper treatment. The objective of this study was to evaluate a model for analyzing respiratory function according to body composition, by analyzing the structure and function of the airways by computed tomography (CT). Lung function and body fat percentage (BF%) were measured in three male subjects (25 ± 6 years), with different body mass index (BMI; normal, overweight, obese). A third-dimensional (3D) reconstruction of the airways was performed using CT. Trachea, right and left main bronchi and anterior segmental bronchus of the right and left lung were measured. Three measurement points were established for each structure, and the average value of these three points was used for the analysis. An increase in the thickness of the airways wall of the left and right main bronchi and right segmental bronchus was observed as BMI and BF% increased. The same was observed for the percentage of airway wall area (%AWA) and airway resistance in the main and segmental bronchi. The proposed 3D reconstruction model and the three-point analysis simplified image assessment and allowed to observe the problems caused by obesity in lung function.

RESUMEN: La obesidad es una epidemia mundial, la que se ha transformado en un factor de riesgo en el desarrollo problemas respiratorios. Al respecto, generar modelos de evaluación de la función pulmonar en pacientes obesos es relevante para su adecuado tratamiento. El objetivo de este trabajo fue evaluar un modelo de la estructura y función de las vías aéreas (VA) con tomografía computarizada (TC) que permita analizar su compor- tamiento de acuerdo a la composición corporal. A tres sujetos de sexo masculino (25±6 años), de distinto índice de masa corporal (IMC; normal, sobrepeso, obeso), se les midió función pulmonar y porcentaje de grasa corporal (% GC). A través de TC se realizó una reconstrucción en tercera dimensión (3D) de las VA. Se realizaron mediciones de las VA de la tráquea, bronquios principales derecho e izquierdo y bronquio segmentario anterior del pulmón derecho e izquierdo. Para cada estructura se establecieron tres puntos de medición, el valor utilizado para los análisis fue el promedio de estos tres puntos. En los tres participantes se observó un aumento del grosor de la pared de las vías aéreas de los bronquios principal derecho e izquierdo y bronquio segmentario derecho a medida que aumenta el IMC y el % GC. Por otra parte, el porcentaje de área de la pared de las vías aéreas (% APVA) se comportó de la misma manera para ambos bronquios principales y segmentarios. La resistencia de las vías aéreas (RVA), tanto general como específica, aumentó en paralelo con el % APVA en los bronquios principales y segmentarios. A través de un modelo de reconstrucción 3D de la estructura de la VA por TC, evaluando tres puntos, se pudo observar los problemas que trae la obesidad a la función pulmonar simplificando el análisis de imagen.

3-D airway analysis related to facial morphology / Análisis 3-D de la vía aerea relacionado con la morfología facial

The aim of this investigation was to define the volume and area of the airway in subjects with Class II and Class III skeletal deformity. A cross-sectional study was designed including subjects with facial deformity defined by Steiner's analysis in subjects with indication of orthognathic surgery who presented diagnosis by cone beam computerised tomography. We determined the measurements of maximum area, minimum area and volume of the airway. The data were compared using Spearman's test, with statistical significance defined as p<0.05. 115 subjects were included: 61.7 % Class II and 38.3 % Class III, mean age 27.8 years (± 11.6). A significant difference was observed in the area and volume measurements in the groups studied, with significantly smaller measurements found in Class II (p=0.034). The minimum area was 10.4 mm2 smaller in Class II patients than in Class III, while the general volume of the airway was 4.1 mm3 smaller in Class II than in Class III. We may conclude that Class II subjects present a smaller airway volume than Class III subjects.

El objetivo de esta investigación de definir el volumen y área de vía aérea en sujetos con deformidad esqueletal clase II y III. Se diseñó un estudio de corte transversal incluyendo sujetos con deformidad facial definida según análisis de Stainer en sujetos con indicación de cirugía ortognática que presentaran una tomografía computadorizada de haz cónico como elemento diagnóstico; en este examen se determinaron medidas de área mayor, menor de vía aérea y volumen presente; los datos fueron comparados utilizando pruebas estadísticas con el test de spearman considerando el valor de p<0,05 para definir significancia estadística. 115 sujetos fueron incluidos, siendo 61,7 % de tipo clase II y 38,3 % de sujetos clase III, con una edad promedio de 27,8 años (± 11,6). Se observó una diferencia significativa en mediciones de area y volumen en los grupos estudiados, siendo el grupo de clase II significativamente menor (p=0,034). El área de menor tamaño fue 10,4 mm2 en pacientes clase II que en pacientes clase III, mientras que el volumen general de la vía área fue 4,1 menor en los clase II que en los clase III. Es posible concluir que los sujetos de clase II presentan menor volumen de vía área que los sujetos clase III.

Efecto de los dispositivos oclusales sobre la vía aérea en pacientes con bruxismo / Effects of occlusal splints on upper airway in bruxism therapy

Objetivo Para el manejo de los trastornos temporomandibulares y del bruxismo de sueño (BS) se ha recurrido durante años a los dispositivos oclusales rígidos superiores (DORS). Estos dispositivos podrían modificar la posición de la mandíbula induciendo una posición más posterior de la lengua y del hueso hioides, comprometiendo la permeabilidad de la vía aérea superior y agravando los trastornos respiratorios del sueño. Este trabajo tiene como objetivo evaluar el cambio de las dimensiones lineales y de área de la luz de la vía aérea faríngea en pacientes diagnosticados con BS que estén usando un DORS, mediante una telerradiografía lateral. Metodología Se reclutaron 20 pacientes del Hospital de Carabineros, de ambos sexos, diagnosticados con BS probable manejados con un DORS, a los cuales se les tomó una telerradiografía lateral sin DORS y otra con DORS sin modificar la postura para evitar distorsiones por posición craneocervical. Se analizó el área y profundidad faríngea por medio de cefalometría para medir el espacio faríngeo. Resultados Se observaron diferencias estadísticamente significativas en la disminución del área de la orofaringe (promedio: 41,2 mm2, p = 0,035) y la profundidad al nivel del gonion (promedio: 0,38 mm, p = 0,019) y la úvula (promedio: 1,38 mm, p = 0,009). No se encontró correlación entre el aumento de la dimensión vertical y las diferencias dimensionales. Conclusión Bajo las condiciones de este estudio el uso de un DORS produce una tendencia a la disminución del área y profundidad orofaríngea.

Objective The use of the superior rigid occlusal splint (SROS) has been used to management temporomandibular disorders and sleep bruxism for many years. These SROS could change the mandibular position leading to a more posterior position of the tongue and hyoids bone, and compromising the upper airway flow permeability and make sleep-breathing disorders worse. The aim of this study is to evaluate the linear and area changes of lumen in patients with sleep bruxism who are using a SROS, measured by lateral teleradiograph. Methodology The study included 20 patients, of both sexes, from the Hospital de Carabineros, Chile, who were diagnosed with probable sleep bruxism due to using and SROS. The cephalometric analysis was performed of the area and pharyngeal depth in order to measure the pharyngeal space, by obtaining a lateral teleradiograph without SROS and a second teleradiograph using SROS, at the same time, to avoid dimensional variation due to possible craniocervical positional changes. Results A statistical significance was found for oropharynx reduction (mean: 41.2 mm2, P = .035), for the gonion linear depth (mean: 0.38 mm, P = .019), and at uvula level (mean: 1.83 mm, P = .009). No correlations were found between the increasing vertical dimensions using SROS and pharyngeal spaces. Conclusion The using of a superior occlusal splint (SROS) could reduce the oropharyngeal depth and space.

Cervical computed tomography in patients with obstructive sleep apnea: influence of head elevation on the assessment of upper airway volume / Tomografia computadorizada cervical em pacientes com apneia obstrutiva do sono: influência da elevação postural na avaliação do volume das vias aéreas superiores

Objective : Obstructive sleep apnea syndrome (OSAS) has a high prevalence and carries significant cardiovascular risks. It is important to study new therapeutic approaches to this disease. Positional therapy might be beneficial in reducing the apnea-hypopnea index (AHI). Imaging methods have been employed in order to facilitate the evaluation of the airways of OSAS patients and can be used in order to determine the effectiveness of certain treatments. This study was aimed at determining the influence that upper airway volume, as measured by cervical CT, has in patients diagnosed with OSAS. Methods : This was a quantitative, observational, cross-sectional study. We evaluated 10 patients who had been diagnosed with OSAS by polysomnography and on the basis of the clinical evaluation. All of the patients underwent conventional cervical CT in the supine position. Scans were obtained with the head of the patient in two positions (neutral and at a 44° upward inclination), and the upper airway volume was compared between the two. Results : The mean age, BMI, and neck circumference were 48.9 ± 14.4 years, 30.5 ± 3.5 kg/m2, and 40.3 ± 3.4 cm, respectively. The mean AHI was 13.7 ± 10.6 events/h (range, 6.0-41.6 events/h). The OSAS was classified as mild, moderate, and severe in 70%, 20%, and 10% of the patients, respectively. The mean upper airway volume was 7.9 cm3 greater when the head was at a 44° upward inclination than when it was in the neutral position, and that difference (17.5 ± 11.0%) was statistically significant (p = 0.002). Conclusions : Elevating the head appears to result in a significant increase in the caliber of the upper airways in OSAS patients.

Objetivo : A síndrome de apneia obstrutiva do sono (SAOS) tem uma alta prevalência e riscos cardiovasculares significativos. É importante estudar novas abordagens terapêuticas para essa doença. A terapia posicional pode ser benéfica na redução do índice de apneia-hipopneia (IAH). Métodos de imagem têm sido utilizados para facilitar a avaliação das vias aéreas em pacientes com SAOS e podem ser utilizados para determinar a eficácia de determinados tratamentos. O objetivo desse estudo foi determinar a influência do volume das vias aéreas superiores, mensurado por TC cervical, em pacientes diagnosticados com SAOS. Métodos : Estudo observacional transversal com abordagem quantitativa. Dez pacientes com diagnóstico de SAOS por polissonografia e avaliação clínica foram submetidos a TC cervical convencional em posição supina com a cabeça em posição neutra e com inclinação de 44° para comparar os volumes das vias aéreas superiores. Resultados : As médias de idade, IMC e circunferência cervical foram de 48,9 ± 14,4 anos, 30,5 ± 3,5 kg/m2 e 40,3 ± 3,4 cm, respectivamente. A média de IAH foi de 13,7 ± 10,6 eventos/h (variação, 6,0-41,6 eventos/h). Quanto à gravidade da SAOS, 70%, 20% e 10% dos pacientes foram classificados como com SAOS leve, moderada e grave, respectivamente. O volume das vias aéreas superiores foi 7,9 cm3 maior com a inclinação de 44° da cabeça quando comparada à posição neutra, e essa diferença foi estatisticamente significativa (17,5 ± 11,0%; p = 0,002). Conclusões : A elevação cervical parece resultar em um aumento significativo do calibre das vias aéreas superiores em pacientes com SAOS.

Broncoscopia / Bronchoscopy

O exame endoscópico das vias aéreas é procedimento realizado com fins diagnósticos, terapêuticos e de pesquisa. A evolução dos equipamentos e métodos de processamento de imagem permite que, com segurança, hoje se realize uma variedade de procedimentos adequados conforme as necessidades das situações clínicas específicas. O procedimento requer treinamento adequado, que obrigatoriamente deverá incluir familiaridade e experiência com endoscopia rígida e flexível. Mais recentemente, o advento dos procedimentos terapêuticos minimamente invasivos por via broncoscópica direcionados a patologias que, outrora, ou seriam tratadas apenas cirurgicamente ou não seriam tratadas, findou por adicionar novas modalidades terapêuticas ao arsenal terapêutico já existente. Assim sendo, exige-se do especialista mais preparo específico para que possa familiarizar-se e utilizar essas tecnologias em rápida evolução (AU)

Airway endoscopy is a procedure utilized mostly for diagnostic, therapeutic and also for research purposes. The technological improvements in equipment and image processing has allowed that a number of procedures can be performed safely, according to what is required by the different clinical situations. The bronchoscopic procedure requires specific trainning and experience in both flexible and rigid bronchoscopy. The recent advances in minimally invasive procedures has ultimately included a new array of therapeutic bronchoscopy for diseases which would otherwise not be treated, or offered only surgery, ended up adding a new variety of procedures that demand constant updates for the specialist to keep up with this rapidly evolving technology (AU)

Relation between clinico-radiological grading and respiratory functions in bilharzial corpulmonale

This work comprised 18 patients with variable degrees of bilharzial corpulmonale and 18 control subjects of different age and sex. They were subjected to thorough clinical examination and different laboratory, radiological, electro-cardiographic and pulmonary function investigations. It was found that, respiratory functions was impaired in patients with bilharzial corpulmonale, both restrictive and obstructive ventilatory dysfunctions. The clinical grading gives an diea about the obstructive dysfunction while radiological grading given an idea about the restrictive ones. On the other hand the clinical grading more or less equal to the radiological grading, So, the clinical examination can tell us abuot the expected radiological findings in those patients