Donor lungs from donation after circulatory death (DCD) are an important supplementary source for expanding the donor pool in lung transplantation. Compared with donor lungs from donation after brain death (DBD), DCD donor lungs undergo hypoventilation, hypoxia, hypoperfusion, circulatory arrest, and functional warm ischemia after withdrawal of life-sustaining treatment. Consequently, varying degrees of pre-preservation injury may already be present before cold flushing and static hypothermic preservation and may further accumulate during preservation, rewarming, and reperfusion. Disruption of mitochondrial homeostasis may serve as a key link between these continuous injury phases and reperfusion vulnerability. The major mechanisms include impaired recovery of oxidative phosphorylation, metabolic reprogramming, increased reactive oxygen species generation, calcium dyshomeostasis, mitochondrial permeability transition pore opening, and dysregulation of mitochondrial dynamics and quality control. These alterations intersect with apoptosis, necroptosis, pyroptosis, ferroptosis, and other lytic cellular injury phenotypes. In recent years, controlled hypothermic storage at 10°C, ex vivo lung perfusion-based assessment and repair, optimization of procurement workflows, and metabolic interventions have provided new directions for DCD donor lung preservation and utilization. However, a substantial proportion of the available mechanistic evidence is derived from general donor lungs, marginal donor lungs, or models of lung ischemia-reperfusion injury and cannot be directly extrapolated to DCD lungs with different injury burdens. This review summarizes the continuous process of DCD donor lung preservation injury, mitochondrial homeostasis disruption, related cellular injury phenotypes, and preservation and dynamic assessment strategies. Evidence directly derived from DCD lungs is distinguished from lung transplantation-related evidence and cross-organ mechanistic references. These findings may inform donor-lung protection and optimization of lung transplantation workflows involving DCD donors.
ObjectiveTo investigate the clinical feasibility and safety of uniportal video-assisted thoracoscopic surgery (VATS) without chest tube in enhanced recovery thoracic surgery.MethodThe clinical data of patients with pulmonary bulla, pulmonary nodules and mediastinal tumors who underwent uniportal VATS in Department of Thoracic Surgery in the Affiliated Hospital of Inner Mongolia Medical University between January 2015 to May 2018 were retrospectively analyzed. A total of 78 patients did not receive closed thoracic drainage tube (a tube-free group), including 30 males and 48 females aged 32.5±8.3 years, 92 patients closed thoracic drainage tube after operation (a control group), including 38 males and 54 females aged 31.4±13.6 years. The surgery-related indicators, postoperative complications and visual analogue score (VAS) were compared between the two groups.ResultsThe time of early ambulation and hospital stay after operation in the tube-free group (1.0±0.3 d, 3.3±0.7 d) were significantly shorter than those in the control group (1.8±0.6 d, 5.2±0.8 d) (P=0.000, P=0.000). The VAS pain scores on the first, second and third day after operation in the tube-free group (4.5±1.8, 3.6±2.4, 2.5±1.4) were also significantly lower than those in the control group (6.8±2.2, 5.7±2.9, 3.9±1.2) (P=0.000, P=0.000, P=0.000). Operation time and intraoperative blood loss in the tube-free group (55.3±12.2 min, 21.5±5.1 mL) and the control group (57.1±6.5 min, 22.2±3.5 mL) were not statistically different (P=0.220, P=0.146). There was no pulmonary infection in both groups, and the wound healing rate was 100.0%. There was no significant difference in pneumothorax, pleural effusion, arrhythmia and re-insertion of chest drain between the tube-free group (5 patients, 8 patients, 1 patient, 3 patients) and the control group (1 patient, 4 patients, 2 patients, 1 patient, P=0.145, P=0.134, P=0.885, P=0.499).ConclusionIn strictly screened patients undergoing uniportal thoracoscopic surgery, no thoracic closed drainage tube can relieve postoperative pain, promote early ambulation activities and enhanced recovery of patients.