Abstract: Objective To evaluate the guiding values of different lung compressed forms in the choice of the treatment of spontaneous pneumothorax. Methods Based on lung compressed forms on anterior-posterior chest X-ray , a total of 219 spontaneous pneumothorax patients were divided into the periphery shape group (n=127) and irregular shape group(n=92). We observe the relationship between lung compressed form with the times of previous closed thoracic drainage， the cure rate of closed chest drain at the 7th day， length that closed thoracic drainage cure pneumothorax and the incidences of the surgical pleural adhesion. Results We found that the incidence of irregular lung compression in 0, 1 and 2 times of receiving previous drainage were 11.71% (13/111), 57.89% (22/57) and 90.19% (46/51) respectively. Its incidence increased with the times of previous closed chest drain (χ2=96.339, P < 0.01). In total, 94 patients (85 of which were cured until the 7th day) and 30 patients (11 of which were cured until the 7th day) were cured using close chest drain in peripheral shape and irregular shape group. And the 7th day cure rate is lower in irregular group than that in the peripheral shape. [36.7%(11/30) vs 90.4%(85/94), χ2=37.596, P < 0.01]. What’ s more, patients in irregular group need longer time to cure pneumothorax than patients in peripheral shape did [d:10.1±4.87 vs 4.00±2.07, t=9.806, P<0.01]. Among the 95 patients who underwent surgical treatment in both groups, the incidence of pleural adhesion is higher in irregular shape group than that in peripheral shape group [91.9%（57/62） vs18.2%（6/33), χ2=52.445, P < 0.01]. Conclusion The 7th day cure rate in patients with peripheral shape lung compressed form is higher than patients in irregular lung compressed form using closed chest drain with fewer incidence of pleural adhesion and shorter cure time. Those with irregular lung compression is more appropriate for surgical treatment.

Key words: spontaneous pneumothorax, lung compressed form, closed thoracic drainage, pleural adhesion, peripheral
shape, irregular shape