To explore the unique mechanism and provide clinical experience in the prevention and management of delayed pneumomediastinum occurring after sublobectomy and extubation of thoracic closed drainage tube.

Four clinical cases with delayed pneumomediastinum that occurred after sublobectomy, extubation and discharge from 2021 to 2022 at the Shaoxing People’s Hospital were retrospectively analyzed.

High-risk lung incision involving segmental/subsegmental bronchi, which might cause extensive wedge resection and substandard segmentectomy, increase the incidence of postoperative delayed pneumomediastinum. Delayed pneumomediastinum were often induced by a sudden increase in alveolar pressure, with a typical manifestation of rapidly progressive mediastinal and subcutaneous emphysema, and resulted in anxiety and fear in patients easily. Delayed pneumomediastinum generally does not require surgical intervention, and thoracic closed drainage is an effective treatment. For high-risk lung incision with high closure tension and possibly involving small bronchi, continuous back-and-forth suture reinforcement during the operation may prevent the occurrence of delayed pneumomediastinum.

Delayed pneumomediastinum after sublobectomy has its own unique mechanism, which may be related to the high-risk lung incision caused by extensive wedge resection and substandard segmentectomy. Intraoperative suture reinforcement of the above-mentioned high-risk lung incision might reduce or even prevent the occurrence of delayed pneumomediastinum.