CT-defined visual emphysema in smokers with normal spirometry: association with prolonged air leak and other respiratory complications after lobectomy for lung cancer.

OBJECTIVES

To evaluate the association of visual emphysema on preoperative CT with respiratory complications and prolonged air leak (PAL) in smokers with normal spirometry who underwent lobectomy for lung cancer.

METHODS

Among patients who underwent lobectomy for lung cancer between 2018 and 2019 at a single center, ever-smokers with normal spirometry were identified retrospectively. Visual emphysema was graded for centrilobular emphysema (CLE) and paraseptal emphysema (PSE), respectively, by two thoracic radiologists. The associations of visual emphysema with PAL and respiratory complications (except PAL) were investigated.

RESULTS

In total, 282 patients were evaluated (257 men; mean age, 64.6 ± 9.8 years). Visual emphysema was present in 126 patients (44.7%) (CLE, 26; PSE, 40; combined CLE and PSE, 60). PAL and respiratory complications occurred in 34 (12.1%) and 26 patients (26.9%), respectively. Greater frequency of PAL and respiratory complications were observed in patients with higher grades of CLE (p = 0.002 for PAL; p = 0.039 for respiratory complications) and PSE (p < 0.001 for PAL; p < 0.001 for respiratory complications). For reader 1 evaluation, the presence of both CLE and PSE was associated with PAL (adjusted odds ratio [OR], 4.94; 95% confidence interval [CI], 1.75-13.95; p = 0.003). For reader 2 evaluation, PSE (adjusted OR, 4.26; 95% CI, 1.22-14.97; p = 0.024) and combined CLE and PSE (adjusted OR, 3.49; 95% CI, 12.1-10.06; p = 0.020) were associated with PAL. The presence of solely CLE was not associated with any adverse outcome (all p > 0.05) for both readers.

CONCLUSIONS

Visual assessment of PSE in smokers with normal spirometry may help identify those who develop PAL after lobectomy.

KEY POINTS: • Visual emphysema was highly prevalent (44.7%) in smokers with normal lung function who underwent lobectomy for lung cancer. • Increasing tendency of postoperative complications was observed as the grade of visual emphysema increased. • The presence of paraseptal emphysema was associated with prolonged air leak.