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A1524 - Pneumothorax in Adult Pulmonary Langerhans Cell Histiocytosis
Author Block: A. Tazi1, P. Le Guen2, E. Bugnet2, C. de Margerie-Mellon3, A. Seguin-Givelet4, G. Lorillon2, D. Gossot4, S. Chevret5; 1Centre National de Référence des Histiocytoses, Service de Pneumologie, AP-HP, Hôpital Saint-Louis; Université Paris Diderot Sorbonne Paris Cité; U1153 CRESS, Equipe de Recherche en Biostatistiques et Epidémiologie Clinique, Paris, France, 2Centre National de Référence des Histiocytoses, Service de Pneumologie, AP-HP, Hôpital Saint-Louis, Paris, France, 3Service de Radiologie, AP-HP, Hôpital Saint-Louis; Université Paris Diderot Sorbonne Paris Cité, Paris, France, 4Département Thoracique, Institut du Thorax Curie-Montsouris, Institut Mutualiste Montsouris, Paris, France, 5Service de Biostatistique et Information Médicale, AP-HP, Hôpital Saint-Louis; Université Paris Diderot Sorbonne Paris Cité; U1153 CRESS, Equipe de Recherche en Biostatistiques et Epidémiologie Clinique, Paris, France.
RATIONALE: Pneumothorax occurs in about 20% of adult pulmonary Langerhans cell histiocytosis (PLCH) patients at any time during the course of the disease. It may be bilateral and/or recurrent, and its management is not standardized. Our objective was to evaluate the risk of ipsilateral recurrence(s) among PLCH patients according to the treatment of their pneumothorax. METHODS: This retrospective study included all patients 18 years of age or older of the National Reference Center for Histiocytoses, between 11/2003 and 12/2015, who presented at least one pneumothorax and were followed for at least 6 months. The primary outcome was the time to ipsilateral recurrence of pneumothorax, considering any hemithorax previously affected. Time to first recurrence from the date of resolution to the date of a new pneumothorax or last follow-up was estimated by the Kaplan Meier method. Univariate Cox models were used for the predictive analysis of time to recurrences, whatever their rank. RESULTS: Forty-three patients (median age 26.5 years, 26 men, 39 current smokers; 30 isolated PLCH) were included. Pneumothorax was the initial manifestation of PLCH in 28 (65%) patients. It was bilateral in 5 cases, accounting for 48 hemithorax events. Chest tube drainage was the first-line treatment in 30 patients. Thoracic surgery was necessary in half of the patients to obtain pneumothorax resolution. During their follow-up (median time 49 months), 53% of patients presented at least one pneumothorax recurrence (median number of pneumothorax per patient 2, [IQR 1-3]). Forty-four ipsilateral recurrences occurred in 20 patients, within 2 years after the first episode in all cases. Thoracic surgery did not modify the cumulative incidence of occurrence of the first ipsilateral recurrence, as compared with chest tube drainage (p= 0.96). The overall rate of recurrences was similar after conservative vs. surgical treatment. However, the rate of ipsilateral recurrences was significantly lower after thoracotomy as compared to after videothoracoscopy (p=0.03). At the time of first pneumothorax, lung function air trapping was associated with increased hazard of pneumothorax recurrence (p=0.03). Twenty-two patients were weaned for tobacco during the study, but smoking status at each pneumothorax episode did not influence the hazard of ipsilateral pneumothorax recurrences (p=0.35). CONCLUSIONS: In PLCH, thoracic surgery is often necessary to resolve the first pneumothorax episode. Ipsilateral recurrences are frequent and occur over a short period of time. Thoracic surgery does not globally decrease the risk of recurrences, but thoracotomy appears more effective than videothoracoscopy for prevention of subsequent pneumothorax.