Pneumatoceles in postpneumonic empyema: an algorithmic approach.

PURPOSE: The aim of the study was to determine the natural course and select appropriate therapy for pneumatocele (PC) in children with postpneumonic empyema.

MATERIALS AND METHODS: Records of 134 children treated for postpneumonic empyema between October 1997 and June 2003 were reviewed retrospectively, and 58 (43%) of them were found to have PC. Their chest x-rays and computed tomography scans as well as patient profiles were evaluated to assess the size, location, course, and complications. Clinical course, treatment indications, and results were also reviewed.

RESULTS: The patients were aged from 14 months to 15 years (mean 3.8 years). There were 36 boys and 22 girls. The PC was located on the right hemithorax in 34 patients and on the left in 24. Staphylococcus aureus was the most common isolated infective agent. Of the 58 children, 37 (63.7%) showed complete resolution with improvement of the infection within 2 months. Thirteen PCs had evidences of gradual decrease in size without any indication for invasive approaches, and they resolved completely, with a mean time of 6.1 (ranging from 1-13) months. One tension PC, 3 large PCs (>50% of hemithorax), 1 case with bad tolerance to follow-up, and 2 persistent PCs had no reduction in size on follow-up; a total of 7 patients underwent image-guided catheter drainage procedure, and 5 of them resolved completely. In the last 2 cases, surgical excision was required because of persistent cystic cavity caused by thickened PC wall. One patient whose PC had not been decreasing in size developed findings of severe lung abscess with thickened wall and directly underwent surgery. In none of these patients recurrences or complaints related to PC were noted on their control visits.

CONCLUSION: Most of these PCs are simple PC and show spontaneous resolution with improvement of the infection within the first 2 months. However, some decrease gradually by time, and close follow-up should be continued in case of complicated PC. Persistent features of chest infection, more than 50% involvement of hemithorax and severe atelectasis, development of broncopleural fistulae (tension PC), and bad tolerance to follow-up remind complicated PC, and they are indications of image-guided catheter drainage procedure. Its failure occurs in PC with thickened wall that does not collapse, as was in our cases with persistent PC and severe infected PC, and thus, this is an indication for surgical excision.