While minimizing parenchymal loss is preferred in the surgical treatment of lung cancer, there are cases where pneumonectomy becomes unavoidable. The higher rates of postoperative mortality and morbidity associated with pneumonectomy compared to other lung resections highlight the importance of careful patient selection [4,5,6]. This study aimed to emphasize the prognostic importance of the development of postoperative complications in patients who underwent pneumonectomy and to examine the risk factors affecting its development. Our findings highlight the significance of smoking amount and operation side as an independent risk factor for developing early postoperative complications. In addition, the amount of smoking and pericardial invasion were found to be associated with postoperative hemorrhage and advanced age with postoperative pneumonia.

In our study, the development of postoperative complications was found to be associated with poor prognosis. The relationship between the development of postoperative complications and poor prognosis after lung resections has been demonstrated in different studies [7,8,9,10]. It is well recognized that postoperative complications can prolong hospital stay, delay recovery, and increase the risk of mortality. The occurrence of complications after lung resection can lead to prolonged inflammation, impaired wound healing, and compromised pulmonary function. These factors may contribute to a higher risk of disease recurrence and decreased overall survival rates. This hypothesis was also supported in various studies in which the development of postoperative complications was considered as a prognostic factor. Lugg et al. [11] revealed the relationship between the development of postoperative complications and poor prognosis and explained this situation with the increased rate of respiratory dysfunction in the patient group with postoperative complications. In other studies, Alifano et al. [12] and Shinohara et al. [13] emphasized the relationship between C-reactive protein, interleukin-6, and tumor necrosis factor-α levels, which expect to increase in the presence of surgery-related complications, with cancer progression. However, there are few studies examining the postoperative complication-prognosis relationship specific to pneumonectomy [14, 15]. Alloubi et al. [14] emphasized that the development of postoperative complications after pneumonectomy is associated with high mortality and that maximum attention should be paid in cases of advanced age and heart failure. In another study, Gu et al. found no association between postoperative complications and overall or recurrence-free survival [15].

In previous studies many different risk factors like advanced age, high ASA physical status, chronic obstructive pulmonary disease, coronary artery disease, diabetes, right pneumonectomy, and smoking have been focused on the development of postoperative complications after pneumonectomy [14, 16, 17]. The possible pathogenesis of tobacco smoking, which was also found to be effective on the development of postoperative complications in our study, is well known. Increased secretion production, decreased macrophage function, decreased ciliary motility, and increased serum carboxyhemoglobin levels are known effects of smoking on the respiratory system [18, 19]. With these mechanisms, smoking can cause an increase in postoperative pulmonary complications. In addition to studies revealing the risks created by the cumulative effect of smoking, there are also studies emphasizing the positive effects of smoking cessation before the operation, regardless of the amount of previous smoking [20]. Although we could not reveal the effect of smoking cessation before the operation due to insufficient data in our study, we were able to show that the amount of past smoking had an effect on the development of postoperative complications.

In our study, right pneumonectomy was found to be an independent risk factor for postoperative complications. This situation has also been demonstrated in similar studies, and the higher alveolar reserve of the right lung and the anatomically more sheltered localization of the left hilum have been suggested as possible causes [21].

Another postoperative complication we would like to emphasize is hemorrhage. In our study, 9 patients were reoperated for postoperative hemorrhage, and the amount of smoking and pericardial invasion were found to be independent risk factors. Studies in the field of thoracic surgery focused on the effect of smoking in terms of postoperative respiratory complications. However, few studies from other surgical branches have reported that smoking increases the rates of postoperative bleeding, referring to its demonstrated negative effects on the coagulation cascade and platelet aggregation [22, 23].

Although intrapericardial pneumonectomy has been associated with increased the risk of postoperative mortality, tachyarrhythmia and cardiac herniation, no study associated with postoperative hemorrhage has been found [24]. Missing a bleeding focus on the pericardial dissection site or performing a more aggressive lymph node curettage in these cases can be considered as possible causes of postoperative hemorrhage.

Pneumonia was the most common major postoperative complication in most series [25, 26]. Advanced age, male gender, atelectasis, and smoking have been reported as risk factors for post-pneumonectomy pneumonia [4,5,6, 25, 26]. Consistent with the literature data, pneumonia was the most common postoperative complication in also our series with a rate of 10.3% and advanced age was found as an independent risk factor (OR: 1.10; P: 0.044).

This study has several limitations that should be acknowledged. First, the retrospective nature of the study design introduces inherent limitations, such as potential selection bias and incomplete data collection. The reliance on medical records and available data may have resulted in missing or incomplete information, which could impact the accuracy and generalizability of the findings.

Secondly, the sample size in this study was relatively small, which might limit the statistical power and generalizability of the results. A larger sample size and multi-center studies would provide more robust and representative findings.

Thirdly, this study was conducted at a single institution, which may limit the generalizability of the findings to other healthcare settings and populations. The variations in surgical techniques, perioperative care, and patient characteristics across different institutions may influence the occurrence and management of postoperative complications.

Lastly, this study primarily examined early postoperative complications and their prognostic importance. Long-term outcomes and survival were not extensively investigated.

Despite these limitations, this study provides valuable insights into the prognostic importance of postoperative complications following pneumonectomy for lung cancer. Future research with larger sample sizes, prospective designs, and multi-center collaborations is needed to validate and expand upon these findings.