Role of surgical manipulation in lung inflammatory response in a model of lung resection surgery.

Objectives: Lung resection surgery with one-lung ventilation leads to an inflammatory response. Surgical manipulation can play a key role in this response. Sevoflurane, a commonly used volatile anaesthetic, has a proven anti-inflammatory effect. Our main goal was to evaluate the segregated effect of surgical manipulation during lung resection surgery and the protective role of sevoflurane with regard to this response.

Methods: Fifteen pigs underwent left thoracotomy for caudal lobectomy under general anaesthesia. The animals were divided into 3 groups: control, sevoflurane and sham. The animals in the sham group underwent left thoracotomy and one-lung ventilation over 120 min, without lobectomy. The animals in the sevoflurane group received anaesthetic maintenance with sevoflurane. The animals in the sham group and the control group received propofol during the procedure. Lung biopsies were collected before the procedure (left caudal lobe) and 24 h later (right mediastinal lobe and left upper lobe). The samples were stored to measure levels of inflammatory markers (IL-1, TNF-α and ICAM-1), apoptotic mediators (BAD, BAX, BCL-2 and Caspase-3), Syndecan-1, MicroRNAs 182, 145 and lung oedema.

Results: Surgical manipulation increased the expression of inflammation (IL-1, TNF-α and ICAM-1) and proapoptotic mediators (BAX, BAD and Caspase-3). It also caused degradation of endothelial glycocalyx (Syndecan-1) and pulmonary oedema. Administration of sevoflurane reduced the elevation of inflammatory markers, degradation of glycocalyx and pulmonary oedema observed in the control group.

Conclusions: Surgical manipulation of the collapsed lung could increase the expression of inflammation and proapoptotic mediators and cause tissue damage in the form of pulmonary oedema. Sevoflurane could attenuate this molecular response and pulmonary oedema.