To thoracoscopically determine the prevalence of emphysema like changes (ELCs) among young healthy adults, and among healthy individuals who are age, gender, height, weight and smoking habit-matched to patients with diagnosis of primary spontaneous pneumothorax (PSP).
We performed bilateral thoracoscopic evaluation of the lungs in healthy individuals who were referred to us for thoracoscopic thoracic sympathectomy. Presence of ELCs, age, gender, height, weight, smoking habits, and pulmonary function tests were documented. Comparisons of these parameters were made between ELC-positive and ELC-negative individuals. Participants were enrolled into a registry, allowing long-term follow-up (6 years). Individuals were then matched to a group of 12 PSP patients (all male, mean age 29.9, range 17 –43, mean height ± standard deviation (SD); 1.79 ± 0.07 meters, mean weight ± SD; 68.7 ± 9.9 kilogram, mean body mass index (BMI) ± SD; 21.3 ± 2.7, smoker/non-smoker 0.6). Prevalence of ELCs among healthy individuals with matched characteristics was evaluated.
Analysis was performed on 250 consecutive cases (male/female 0.4, mean age ± SD; 29 ± 10 years). ELCs were observed in 15/250 (6%) individuals (male/female 6/9, mean age 25.3, range 15 –51). Compared to ELC-negative group, ELC-positive individuals had a significantly lower body mass index (BMI) (20.7 ± 2.4 vs. 22.7 ± 3.4; P = 0.027), whereas all other parameters were similar. ELCs tended to be more prevalent among smokers; however, statistical significance was not achieved (P = 0.76). Similarly, in the matched group, ELCs were observed in 6/101 (6%) individuals. During 6 years of follow-up, none of the ELC-positive individuals has developed pneumothorax.
Thoracoscopically, ELCs were present in 6% of young healthy adults with no underlying lung disease. Low BMI (< 22) appears to play an important role in the development of ELCs.
Given that far less than 6% of the population develops PSP, we hypothesize that ELC’s in PSP population is at least in part due to their physiognomic features and not the obligatory cause of pnemothorax.
Kayvan Amjadi, None.