Acute type A aortic dissection (ATAAD) is an extremely high-risk aortic disease, with a very high early mortality rate, for which the only treatment strategy is surgery, preferably performed as early as possible. Indeed, early surgical repair has been associated with improved prognosis and reduced mortality [1]. Acute respiratory distress syndrome (ARDS) is a common and serious complication in patients with ATAAD following total arch replacement. This complication is associated with high rates of morbidity and mortality [2], which seriously affect the postoperative prognosis and survival rate of these patients [3, 4, 5]. Indeed, in contrast to other cardiovascular operations, ATAAD surgery requires low-temperature and low-flow perfusion, or even circulatory arrest, which can lead to an imbalance in the body’s inflammatory and coagulation systems [6]. Activation of the clotting system is currently considered one of the key factors influencing progression and prognosis in patients with ATAAD [7], while excessive perioperative bleeding and transfusion have been identified as independent risk factors of ARDS after ATAAD [8]. Aortic dissection triggers activation of the coagulation/fibrinolytic system and platelets and the high consumption of coagulation factors and platelets, resulting in increased intraoperative bleeding, one of the most common complications of ATAAD [9, 10]. Consequently, the incidence of postoperative ARDS is among patients with ATAAD.

Early detection and the timely prevention of potential risk factors of postoperative ARDS are important to improve the overall prognosis of patients with ATAAD. However, traditional laboratory tests often fail to accurately reflect and evaluate the overall preoperative coagulation function among patients with ATAAD. As such, rapid identification of the preoperative coagulation function status and coagulation reserve status of patients with TAAD is imperative. Based on these measurements, individualized fibrinogen, coagulation factor, and platelet supplements can be administered to optimize blood transfusion and reduce the occurrence of postoperative ARDS, to improve the overall therapeutic effect and prognosis of patients with TAAD.

The primary finding of this study is that preoperative levels of fibrinogen, the clot angle, and MA are all independent risk factors, with predictive power, for postoperative ARDS in patients with ATAAD. These results further reveal the association between coagulation parameters and the occurrence of ARDS after ATAAD. This study is the first to use TEG to assess the link between coagulation parameters and postoperative ARDS among patients with ATAAD undergoing emergency surgery. Through TEG-based assessments, early detection and the monitoring of individuals at an elevated risk can be accomplished, enabling precise fibrinogen supplementation and improved management of transfusion strategies, thereby providing a scientific basis for the prevention of ARDS and lung-protection strategies following ATAAD.

In this research, the incidence of postoperative ARDS was 16.0% (56/350), and the ARDS group had a longer duration of mechanical ventilation (p = 0.009) compared to those in the non-ARDS group. In the ARDS group, 12 patients required reintubation, four developed respiratory failure, and five died. Aortic surgery poses a significant challenge to cardiovascular surgeons owing to its high mortality rate. Severe perioperative bleeding and blood transfusion are among the most frequent and high-risk complications associated with emergency total aortic arch replacement surgery [13, 14]. Large-volume blood transfusion is a known risk factor for postoperative ARDS in patients with ATAAD [15]. Consistent with increasing evidence that perioperative transfusions of large amounts of red blood cells and plasma are independent risk factors for postoperative ARDS [16, 17, 18], in our study, we found that more red blood cells were transfused during surgery in the ARDS group. In addition, studies have shown that the administration of human fibrinogen prior to aortic surgery can reduce the levels of intraoperative blood loss and the extent of transfusion and shorten the operation time effectively. In addition, it can reduce postoperative complications and improve the early prognosis of patients, indicating a relationship between the coagulation system and ARDS [19].

ATAAD itself is associated with a state of coagulation disorder, whereas the findings of Zindovic et al. [20] suggested that surgery causes additional damage to the coagulation system in patients with ATAAD. Wang et al. [4] further found, through logistic regression models, that the drainage volume 24 h after aortic repair is another independent risk factor for postoperative ARDS. As such, the perioperative coagulation status of patients with ATAAD is a widely accepted clinicopathological indicator of aortic occlusion and CPB-induced coagulopathy during aortic surgery [21]. Prior to emergency aortic surgery, blood contact with the non-endothelial wall of the pseudolumen causes damage to the hemostatic system [21, 22]. Given the activation of the coagulation system before surgery, our research focused on parameters related to the preoperative coagulation system primarily in patients with ATAAD [23]. Routine laboratory tests and TEG allowed for the documentation of early fibrinogen activity, coagulation factor and platelet consumption, and coagulation dysfunction prior to ATAAD. However, to date, no similar research has obtained strong evidence of the relationship between changes in TEG parameters of the coagulation system and postoperative ARDS.

Fibrinogen and platelets are key factors influencing clot formation and strength. Consequently, there has been an increasing emphasis on the role of fibrinogen and platelets in minimizing blood loss and enhancing patient outcomes [24]. Several studies have suggested the use of platelets or fibrinogen to address coagulation dysfunctions [25, 26]. One study also confirmed that fibrinogen and synergistic platelet functions are responsible for the clot strength [27]. Fibrinogen or platelet deficiencies can lead to increased perioperative bleeding, whereas transfusion is associated with postoperative ARDS. In the context of an inflammatory response and coagulopathy, the TEG abnormalities identified in our study likely represent key mechanistic links to the development of ARDS. A low preoperative fibrinogen level reflects the consumption of clotting factors and potentially enhanced fibrinolysis, which may exacerbate endothelial permeability and the release of inflammatory mediators. Similarly, a reduced clot angle indicates impaired fibrin polymerization and cross-linking, leading to an unstable clot that may fail to effectively control local vascular injury and inflammation. A low MA value, reflecting diminished platelet function and its contribution to clot strength, may further exacerbate bleeding tendencies and the need for transfusion, which itself is a potent trigger for inflammatory lung injury. Based on these findings, we propose that changes in TEG parameters associated with postoperative ARDS are predictable and quantifiable in patients with ATAAD.

In addition, when compounded by the systemic insult of CPB and surgery, they may further propel the pathophysiological cascade [17]. This cascade is characterized by amplified inflammation, endothelial damage, and capillary leak, ultimately culminating in ARDS. Owing to the use of extracorporeal circulation in ATAAD surgery, the interaction among nonpulsating blood flow, artificial tubes, the clotting system, and the inflammatory system has been extensively investigated [28, 29, 30]. CPB has also been shown to be associated with an increased incidence of postoperative ARDS [17]. CPB can further lead to the destruction of blood cells and depletion of clotting factors and platelets, with a superimposed effect on the originally collected clotting/fibrinolytic system and platelet activation. CPB may stimulate an inflammatory response, possibly due to blood exposure to abnormal shear forces and contact with artificial duct surfaces [31, 32, 33]. Nteliopoulos et al. [34] previously showed that CPB-induced lung injury is caused by multiple factors, including the artificial surface contact of blood components with CPB circuits, local and systemic inflammatory response syndrome, lung ischemia/reperfusion injury, ventilation arrest, and circulating endotoxin production. Further, Liu et al. [35] showed that the type of surgery, CPB duration, and blood transfusion are all independent risk factors for postoperative pulmonary complications. It is important to note that the factors that induce ARDS involve different systems that can influence each other. However, conventional laboratory tests can only analyze a single systemic factor, whereas the change in TEG parameters is simple and quantifiable, allowing for an objective and immediate reflection of the overall coagulation state of the body, thus helping to guide clinical practice; optimize blood transfusion; reduce blood transfusion reactions; and shorten hemostasis, CPB, and lung ischemia times to reduce lung damage. As such, the early identification and treatment of clotting systems could be life-saving [36]. In some hospitals, the use of TEG-guided perioperative coagulation management has become common practice to monitor coagulation function and minimize the risk of bleeding [37, 38]. As such, TEG can provide a holistic view of the body’s coagulation system before and after ATAAD and can be used to measure platelet function (MA level) and fibrinogen function (fibrinogen and clot angle levels), which could be advantageous for patients with ATAAD.

Overall, the present study identified preoperative fibrinogen, the clot angle, and MA levels as potential predictors of postoperative ARDS in patients with ATAAD. Further, our results showed that TEG allows for a rapid assessment of the status of the coagulation system in patients with ATAAD before surgery, helping to guide preoperative fibrinogen supplementation and strategic blood transfusion to reduce the occurrence of postoperative ARDS in patients with ATAAD and shorten the postoperative mechanical ventilation time. As such, TEG may be a valuable tool for the real-time monitoring and improvement of patient outcomes after surgery.

ATAAD, acute type A aortic dissection; ARDS, acute respiratory distress syndrome; TEG, thromboelastography; MA, maximum amplitude; NYHA, New York Heart Association; LVEF, left ventricular ejection fraction; ECMO, extracorporeal membrane oxygenation; IABP, intra-aortic balloon pump; PaO₂, arterial partial pressure of oxygen; PAWP, pulmonary artery wedge pressure; OI, oxygen index; CI, confidence interval; OR, odds ratio; SD, standard deviation; ROC, receiver operating characteristic curve; CPB, cardiopulmonary bypass; SCP, selective cerebral perfusion.

All data generated or analyzed during this study are included in this published article.

All authors take responsibility for the integrity of the data, the accuracy of the data analysis and the revision of the manuscript. QW designed the study and submitted the manuscript. XW and KY prepared the first draft of the manuscript and made the literature review. QW and ZQ made substantial changes in the manuscript together. XC, YG, and BY collected and analyzed data together. All authors contributed to the conception and editorial changes in the manuscript. All authors read and approved the final manuscript. All authors have participated sufficiently in the work and agreed to be accountable for all aspects of the work.

The study’s retrospective was approved by the Ethics Committee of Union Hospital of Fujian Medical University (ethical approval number: No. 2024KJCX076), and conformed to the Declaration of Helsinki. The requirement for informed consent was waived by the Ethics Committee based on the study’s retrospective analysis of patient data.

The authors would like to express their gratitude to Editage for English language editing, as well as to the Operating Room Nursing Ward of Fujian Medical University Union Hospital for their support.

This work was funded by the Special Fund of Fujian Provincial Finance (2024CZ004), the Fujian Provincial Natural Science Foundation of China (2024J01627), Changji Hui Autonomous Prefecture Science and Technology Project (2025S04-01) and Fujian Provincial Special Reserve Talents Laboratory (No. 2021-25).

The authors declare no conflict of interest.