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.