Efficacy and safety of giant emphysematous bulla volume reduction via medical thoracoscope

Objective: To evaluate the efficacy and safety of giant emphysematous bulla (GEB) volume reduction via medical thoracoscope. Methods: This was a prospective, single-arm study conducted between July 2018 and September 2020 in Ri Zhao Hospital of Traditional Chinese Medicine. Patients who met the inclusion criteria were treated with GEB volume reduction via medical thoracoscope and were followed up to evaluate the efficacy and safety of the technique. According to comparison of preoperative and postoperative chest CT results, the self-designed evaluation criteria of imaging efficacy were as follows: complete or nearly complete disappearance of GEB (GEB volume reduction ≥90%), significant reduction of GEB (75%≤GEB volume reduction<90%), reduction of GEB (50%≤GEB volume reduction<75%) and no change (GEB volume reduction<50%). Results: A total of 47 patients were included, among whom 43 were males, with an age M (Q1, Q3) of 63.0 (55.0, 67.0). The CT results showed complete or nearly complete disappearance of GEB in 43 patients, significant reduction of GEB in 3 patients and reduction of GEB in 1 patient before discharge. The degree of dyspnea improved significantly (P<0.05). Arterial partial pressure of carbon dioxide (PaCO2) decreased from (48.2±8.4)mmHg (1 mmHg=0.133 kPa) to (45.4±7.3)mmHg (P<0.05). The 6-minute walk test (6MWT) increased from (245.6±162.4)m to (283.5±152.2)m (P<0.05). Six-month postoperative follow-up was completed in 24 patients, and CT results showed that the efficacy of volume reduction was continuous compared with that before discharge. GEB was further reduced or even disappeared in 3 of the cases. Besides, the degree of dyspnea, 6MWT (384.4±148.2)m and PaCO2 (42.7±6.6)mmHg were improved significantly (P<0.05). The oxygenation index (356.86±61.21)mmHg was significantly higher than that before surgery (295.20±67.16)mmHg and before discharge (294.50±76.69)mmHg (P<0.05). No perioperative deaths occurred. Conclusions: GEB volume can be completely eliminated or significantly reduced by this innovative technique, while PaCO2, the degree of dyspnea and exercise endurance can be significantly improved after operation. The 6-month follow-up after surgery showed that the above benefits continued, and that the oxygenation index improved significantly.