ABSTRACT
BACKGROUND@#The effectiveness of bronchial thermoplasty (BT) has been reported in patients with severe asthma. This study compared the effects of BT and cryoballoon ablation (CBA) therapy on the airway smooth muscle (ASM).@*METHODS@#Eight healthy male beagle dogs were included in this experiment. In the preliminary experiment, one dog received BT treatment for both lower lobe bronchus, another dog received CBA treatment for 7 s on the upper and lower lobe of right bronchus, and 30 s on the left upper and lower lobe. The treatments were performed twice at an interval of 1 month. In subsequent experiments, the right lower lobe bronchus was treated with BT, and the left lower lobe bronchus was treated with CBA. The effects of treatment were observed after 1 (n = 3) month and 6 months (n = 3). Hematoxylin-eosin staining, Masson trichrome staining, and immunohistochemical staining were used to compare the effects of BT and CBA therapy on the ASM thickness, collagen fibers synthesis, and M3 receptor expression after treatment. One-way analysis of variance with Dunnett post hoc test was used to analyze the differences among groups.@*RESULTS@#In the preliminary experiment, the ASM ablation effect of 30-s CBA was equivalent to that of 7-s CBA (ASM thickness: 30.52 ± 7.75 μm vs. 17.57 ± 15.20 μm, P = 0.128), but the bronchial mucociliary epithelium did not recover, and large numbers of inflammatory cells had infiltrated the mucosal epithelium at 1-month post-CBA with 30-s freezing. Therefore, we chose 7 s as the CBA treatment time in our follow-up experiments. Compared with the control group (35.81 ± 11.02 μm), BT group and CBA group (13.41 ± 4.40 μm and 4.81 ± 4.44 μm, respectively) had significantly decreased ASM thickness after 1 month (P < 0.001). Furthermore, the ASM thickness was significantly lower in the 1-month post-CBA group than in the 1-month post-BT group (P = 0.015). There was no significant difference in ASM thickness between the BT and CBA groups after six months (9.92 ± 4.42 μm vs. 7.41 ± 7.20 μm, P = 0.540). Compared with the control group (0.161 ± 0.013), the average optical density of the ASM M3 receptor was significantly decreased in 6-month post-BT, 1-month post-CBA, and 6-month post-CBA groups (0.070 ± 0.022, 0.072 ± 0.012, 0.074 ± 0.008, respectively; all P < 0.001). There was no significant difference in the average optical density of ASM M3 receptor between the BT and CBA therapy groups after six months (P = 0.613).@*CONCLUSIONS@#CBA therapy effectively ablates the ASM, and its ablation effect is equivalent to that of BT with a shorter onset time. A neural mechanism is involved in both BT and CBA therapy.
Subject(s)
Animals , Dogs , Humans , Male , Bronchi/surgery , Bronchial Thermoplasty , Bronchoscopy , Cryosurgery , Muscle, SmoothABSTRACT
La termoplastía bronquial es un procedimiento broncoscópico que se emplea como herramienta terapéutica en pacientes con asma severa que se mantienen sintomáticos pese a un tratamiento óptimo. El procedimiento consiste en la aplicación de energía térmica controlada endobronquial para lograr la destrucción parcial del músculo liso de la vía aérea, procedimiento conocido como radiofrecuencia oblativa. El procedimiento se ha asociado a mejoría en la calidad de vida, mayores niveles de flujo espiratorio máximo, mayor cantidad de días libres de enfermedad, reducción en la frecuencia de exacerbaciones asmáticas, menor necesidad de broncodilatadores de rescate, menores visitas al servicio de urgencia y menor ausentismo laboral. El procedimiento es considerado seguro cuando se respetan las contraindicaciones, sólo existiendo una mayor tasa se exacerbaciones y hospitalizaciones en el período inmediatamente posterior al procedimiento. Los beneficios se mantienen en el seguimiento a cinco años después del procedimiento. La termoplastía bronquial es una herramienta terapéutica a tener en consideración en pacientes con asma de difícil control.
Bronchial thermoplasty is a tool used in the management of severe asthma that remain symptomatic despite adequate treatment. The procedure consist in the application of endobronchial controlled thermal energy, in order to achieve partial destruction of smooth muscle of the airway, procedure known as ablative radiofrecuency. The technique has been associated to improvement in the quality of life, higher levels of peak expiratory flow, more days free of disease, low exacerbation rates, fewer needs of rescue bronchodilators.
Subject(s)
Humans , Asthma/surgery , Bronchial Thermoplasty/methods , Quality of Life , Patient Selection , Bronchial Thermoplasty/instrumentationABSTRACT
El asma es una enfermedad frecuente de fisiopatología compleja. El asma severa constituye aproximadamente el 5% de la población de asmáticos, sin embargo representa un desafío clínico y una carga sanitaria importante. Estudios recientes demuestran la existencia de fenotipos en todo el espectro de gravedad. La eosinofilia en esputo y sangre ha demostrado utilidad como marcador de inflamación Th-2 y de respuesta clínica a esteroides, sin embargo aún no existe mucho conocimiento sobre el asma no-eosinofílica. Los tratamientos actuales en asma se enfocan a estrategias de terapia escalonada según severidad, pero en pacientes con asma severa se requiere también del manejo multidisciplinario de las comorbilidades y la determinación del fenotipo, para aplicar terapias más especificas. El desarrollo acelerado de nuevos tratamientos en asma severa como consecuencia del mejor conocimiento de los distintos fenotipos ha ampliado el arsenal terapéutico para un enfrentamiento personalizado y específico en los pacientes con asma severa.
Asthma is a common disease of complex pathophysiology. Severe asthma accounts about 5% of asthma population, however represents a clinical challenge and a significant health burden. Recent studies show the existence of phenotypes through all the spectrum of severity. Eosinophilia in blood and sputum has proven as a useful marker of Th-2 inflammation and clinical steroid response, however there is still little knowledge about non-eosinophilic asthma. Current treatments for asthma are focused on step-up approaches according to severity, but severe asthma patients also require multidisciplinary management of comorbidities and phenotyping to apply more specific therapies. The fast development of new treatments in severe asthma as a result of better understanding of different phenotypes has broadened the therapeutic arsenal for a personalized and targeted management in severe asthma patients.