Residual apical space following surgery for pneumothorax increases the risk of recurrence.

OBJECTIVE Residual air spaces on chest radiographs after pneumothorax surgery are not uncommon. We aimed to study their incidence and impact on surgical outcomes. METHODS Four hundred and twenty-seven patients [283 men and 144 women with a median age of 31 (14-96) years] underwent surgery for pneumothorax from 1995 to 2005 in a single unit. Video-assisted thoracoscopy was used in 225 cases (53%). Outcomes were: duration of intercostal drainage and hospital stay, recurrence, re-operation and referral to chronic pain clinic. RESULTS Median duration of intercostal drainage and hospital stay were 5 and 6 days, respectively. We found a recurrence rate of 6.6% (n=28), re-operation rate of 2.8% (n=12) and need for referral to pain clinic of 7% (n=30). In 129 patients (30%) a small residual apical space (RAS) was reported on chest radiograph prior to discharge. Hospital stay and duration of drainage were longer in these cases (p=0.002 and 0.02, respectively). On multivariate analysis RAS on chest radiograph was associated with increased risk of recurrence [hazard ratio 3.1 (1.4-6.8 95% CI)] (p=0.005); but no need for re-operation or referral to pain clinic. Re-operation was associated with VATS surgery (p=0.001) and when no abnormalities were identified at operation (p=0.04). Referral to pain clinic was more common after open surgery (p=0.01). DISCUSSION The risk of recurrence after pneumothorax surgery is low. But the presence of a residual apical space on chest radiography after surgery increases it significantly. Recurrence may be due to the failure to achieve early pleural symphysis.