Risk factors and perioperative complications associated with deep venous thrombosis and pulmonary embolism after lung transplantation

Introduction

Background

Deep venous thrombosis (DVT) and pulmonary embolism (PE) are significant problems after lung transplantation. PE is significantly associated with increased postoperative mortality and morbidities, including prolonged hospitalization, graft failure, and re-transplantation, and pulmonary infarction due to inadequate or absent collateral bronchial circulation. The incidence of venous thromboembolism after lung transplantation is notably higher than in other cardiothoracic surgeries, reported between 8–43% (1-4). There are several independent risk factors for venous thromboembolism associated with lung transplantation, including inflammation and prothrombotic state related to surgical trauma, prolonged immobilization, and fluid imbalance results in decreased venous flow, impaired glucose tolerance and post-transplant diabetes related to immunosuppressive medication, and solid organ transplantation itself (5,6).

Rationale and knowledge gap

Current clinical guidelines recommend various anticoagulation strategies to treat DVT to prevent potential PE. However, it comes at the cost of increasing postoperative bleeding, as post-lung transplant patients are already at high risk for postoperative bleeding due to thrombocytopenia and coagulopathy associated with cardiopulmonary bypass/extracorporeal membrane oxygenation (ECMO), as well as the extensive surgical dissection required to extract native lung in many end-stage lung diseases (7).

Objective

The goal of this study is to investigate the risk factors associated with venous thromboembolism after lung transplantation and to identify factors associated with PE in patients who develop DVT to develop a better strategy for anticoagulation to prevent bleeding. We present this article in accordance with the STROBE reporting checklist (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1294/rc).

Methods

Study design

The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Institutional Review Board of Northwestern University (Nos. STU00207250 and STU00213616). The need for patient consent for data collection was waived by the institutional review board due to the retrospective nature of this study.

Patient data were retrospectively obtained from electronic medical records and entered into a database maintained at Northwestern University Medical Center in Chicago, Illinois, USA. The study included adult patients who underwent lung transplantation at our institution between January 2018 and May 2024. Patients who received multiorgan transplants or underwent re-transplantation were excluded. Collected variables included patient demographics, comorbidities, donor characteristics, preoperative laboratory values, intraoperative and postoperative outcomes, and panel reactive antibody results. This study was designed to evaluate acute postoperative complications, specifically venous thromboembolism and bleeding events, during the index hospitalization and early postoperative period. Chronic complications such as chronic lung allograft dysfunction (CLAD), infection, or late graft failure were not included in this analysis.

ECMO indication criteria

Prior to lung transplantation, selected patients with lung acute respiratory failure who meet guidelines of the National Heart, Lung, and Blood Institute’s Acute Respiratory Distress Syndrome (ARDS) Network (8) were evaluated by multidisciplinary team. Indications for ECMO evaluation included refractory hypoxemia with partial pressure of oxygen (PaO₂) less than 55 mmHg, pulse oximetry oxygen saturation less than 88%, and pH level less than 7.2. Central venous catheters (CVCs) were replaced every 7 days, even if there were no signs of infection. New CVC replacements were performed in a different area or new vein, not a wire-based replacement and weekly surveillance cultures for all ECMO patients were used to monitor bloodstream infections, similar with our previous study (9).

Anticoagulation during veno-venous extracorporeal membrane oxygenation (VV-ECMO) support

Patients did not receive continuous anticoagulation unless there was a specific indication, such as DVT or PE, and there was no monitoring of bleeding parameters, such as activated clotting time or activated partial thromboplastin time, which is consistent with our previous study (10). All patients who were not receiving continuous systemic anticoagulation received 5,000 U of subcutaneous unfractionated heparin every 8 hours (3 times daily) as a prophylactic dose to prevent DVT. VV-ECMO flow was maintained at a minimum of 3.0–3.5 L/min, consistent with our recent reports, to reduce thrombotic complications in the ECMO circuit (10,11).

Definition of complication

Hemothorax/hematoma

Hemothorax was defined as cases identified on imaging as well as those requiring surgical intervention or drainage. Hematoma was defined as cases identified on imaging, including those that required surgical intervention and those that did not require any intervention.

Primary graft dysfunction (PGD)

PGD was defined based on the International Society for Heart and Lung Transplantation (ISHLT) guideline (12), and graded by PaO₂/fraction of inspired oxygen (FiO₂) ratio as follows: Grade 1, PaO₂/FiO₂ ratio >300; Grade 2, PaO₂/FiO₂ ratio is 200–300; Grade 3, PaO₂/FiO₂ ratio <200. The use of ECMO for bilateral pulmonary edema on chest X-ray was classified grade 3.

Acute kidney injury (AKI)

AKI was defined using the risk, failure, loss of kidney function, and end-stage kidney disease classification (13).

Postoperative DVT prophylaxis and surveillance

We administered subcutaneous unfractionated heparin (5,000 U three times daily) for standard postoperative thromboprophylaxis. Duplex ultrasound or further imaging for DVT was performed only when patients developed clinical symptoms suggestive of venous thrombosis; no routine screening protocol was in place for asymptomatic patients. Lower extremity perfusion was assessed clinically and with targeted imaging when indicated.

Statistical analysis

Recipient and donor characteristics, preoperative laboratory values, and intra- and postoperative outcomes were compared. The Mann-Whitney U test was used to compare independent continuous variables between the groups. Fisher’s exact test was used to compare categorical variables, which were reported as numbers and percentages. The Kaplan-Meier method was used to estimate survival, and the log-rank test was performed to compare survival between the groups. Odds ratios (ORs) were obtained using a univariate and multivariate logistic regression analysis. Hazard ratios (HRs) were obtained using a univariate and multivariate cox proportional hazard analysis. Statistical significance was set at P<0.05. All statistical analyses were performed using the JMP Pro 17.0.0 software program (SAS Institute Inc.).

Results

Comparison between patients with DVT and those with no DVT

Of 399 lung transplant recipients, 214 patients (53.6%) developed acute DVT. The median days of development of DVT were 20.0 days. The demographics, preoperative characteristics, and intra-operative outcomes between patients who developed DVT and those who did not were similar (Table 1). The postoperative DVT was associated with increased development of PE (22.4% vs. 5.4%, P<0.001), hemothorax/hematoma (50.5% vs. 29.7%, P<0.001), postoperative graft dysfunction (16.8% vs. 8.1%, P=0.01), acute kidney injury requiring dialysis (22.0% vs. 7.6%, P<0.001), prolonged median ICU stay (9 vs. 6 days, P<0.001) and longer median hospital stay (21 vs. 14 days, P<0.001) compared to patients without DVT. As Figure 1A shows, the patient with DVT had increased postoperative mortality (P<0.001). In the multivariate analysis, lung transplantation for pulmonary artery hypertension had a lower incidence of DVT [OR 0.33, 95% confidence interval (CI): 0.15–0.74, P=0.007] (Table 2).

Figure 1 Overall survival of lung transplant recipients stratified by postoperative complications. Kaplan-Meier curves compare survival in patients with versus without (A) deep venous thrombosis (no DVT vs. DVT; P=0.0002), (B) patients with DVT who developed PE and those who did not (no PE vs. PE; P=0.39), and (C) bleeding complications (no bleeding vs. hemothorax/hematoma; P<0.0001). DVT, deep vein thrombosis; PE, pulmonary embolism.

Comparison of patients with DVT who developed PE and those with no PE

Of 214 lung transplant patients who developed postoperative DVT, 48 patients developed PE. There was no difference in the overall survival of patients with DVT who developed PE and those who did not (Figure 1B). The demographics, preoperative characteristics, and intraoperative outcomes of patients with DVT who developed PE and those who did not were similar (Table 3). In the multivariate analysis, among patients with DVT, lower extremity DVT (OR 2.14, CI 1.05-4.36, p = 0.04) and elevated preoperative platelet count (OR 1.00, 95% CI: 1.00–1.01, P=0.046) were associated with a higher incidence of PE (Table 4).

Predictors of mortality within the DVT cohort

Among patients who developed postoperative DVT (n=214), we performed a multivariate Cox regression analysis to identify risk factors for mortality. As shown in Table S1, postoperative hemothorax/hematoma was independently associated with increased mortality (HR 2.24, 95% CI: 1.32–3.81, P=0.003). In contrast, PE was not associated with survival (HR 1.12, 95% CI: 0.62–1.99, P=0.72). AKI and PGD grade 3 demonstrated non-significant trends toward higher mortality.

Comparison of patients with hemothorax/hematoma and those with no hemothorax

Out of 399 patients, 163 developed postoperative hemothorax or hematoma. Forty patients required re-operations. As shown in Figure 1C, patients who developed postoperative hemothorax had a decreased overall survival compared to those who did not (P<0.0001). Comparing patients with bleeding complications, patients who developed hemothorax/hematoma were more likely to be on hemodialysis (8.6% vs. 2.5%, P=0.009), on ECMO (15.3% vs. 6.8%, P=0.007), and have lower platelet level (225 vs. 268, P<0.001) before the surgery and required more blood transfusion (3.1 vs. 1.7 U, P=0.01) and platelets (0.7 vs. 0.3 pack, P=0.001) during the index operation compared to those who did not have bleeding complications (Table 5). The patients who developed postoperative hemothorax/hematoma were more likely to have developed DVT (66.3% vs. 44.9%, P<0.0001) and digital ischemia (3.1% vs. 0.4%, P=0.04), on postoperative ECMO (22.7% vs. 5.5%, P<0.0001), associated with acute kidney injury (55.8% vs. 41.1%, P=0.004) and required dialysis (26.4% vs. 7.6%, P<0.001), and developed PGD (20.8% vs. 7.2%, P<0.001) than those without bleeding complications. The ICU days (10 vs. 6 days, P<0.001) and length of hospital stay (24 vs. 15 days, P<0.0001) were also prolonged in those who developed postoperative bleeding complications.

Discussion

Key findings

DVT and PE are significant problems associated with substantially increased morbidity and mortality in postoperative patients undergoing major operations such as lung transplantation (14-16). Perioperative factors inherent to lung transplantation further predispose patients to prothrombotic states (17-19). In our single-center cohort of 399 lung transplant recipients, postoperative DVT developed in 53.6% of patients. Patients with DVT experienced significantly worse outcomes, including higher postoperative mortality (33.2% vs. 13.0%), an increased risk of PE (22.4% vs. 5.4%), a greater incidence of hemothorax or hematoma (50.5% vs. 29.7%), and longer ICU and hospital stays compared to those without DVT. Multivariate analysis revealed that transplantation for pulmonary arterial hypertension was independently associated with a lower incidence of DVT, which may reflect routine preoperative anticoagulation in this population. Among patients with DVT, lower extremity thrombosis and elevated preoperative platelet count were independently associated with the development of PE, although PE itself was not associated with increased mortality. Importantly, patients with DVT were more likely to develop bleeding complications, raising concern that anticoagulation strategies to prevent PE must be carefully balanced against the heightened risk of postoperative hemorrhage.

Strengths and limitations

Strengths of this study include a large, well-characterized cohort with standardized definitions and comprehensive multivariate adjustment. Limitations arise from its retrospective, single-center design—potentially limiting generalizability and introducing selection bias—and reliance on electronic medical records, which are subject to clerical entry errors, lack of granularity in data and missing data. Because DVT screening was only performed in symptomatic patients, asymptomatic cases may have been underdiagnosed, especially in sedated or critically ill patients. Thus, our reported incidence may underestimate the true burden of postoperative DVT. Another limitation of our study is the absence of certain preoperative functional and physiological variables, such as activities of daily living (ADL), P/F ratio, and duration of ECMO support. These parameters may have an important impact on thrombotic risk and should be addressed in future prospective studies. Another limitation is that our analysis was confined to acute-phase complications and early postoperative outcomes. We did not capture chronic complications such as CLAD, opportunistic infections, or chronic graft failure, which are important determinants of long-term survival. Therefore, our survival analyses should be interpreted primarily in the context of early perioperative events, and future studies with longer-term follow-up will be necessary to determine the relationship between VTE and late outcomes. Finally, we did not capture detailed information on preoperative antithrombotic therapy. Such data may be important, as prior use of anticoagulants or antiplatelet agents could influence both the incidence of thrombotic complications and the risk of postoperative bleeding. Future prospective studies should incorporate this variable to refine risk stratification.

Comparison with similar research

Current guidelines endorse pharmacologic prophylaxis for major surgery and therapeutic anticoagulation once DVT is diagnosed (20-23). Analyses of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database by Bellomy et al. showed that postoperative bleeding carries greater attributable mortality than VTE, mirroring our finding that hemorrhagic complications rival PE in impact. Levy et al. (24) similarly demonstrated minimal PE risk from upper-extremity DVT, analogous to our observation that lower-extremity DVT and elevated preoperative platelets—rather than DVT location alone—stratify PE risk in lung transplant recipients.

It is interesting to note that the incidence of postoperative DVT (53.6%) in our study was much higher than many prior reports. We believe this reflects differences in patient population and perioperative management rather than a systematic screening effect, as our institution does not perform routine duplex ultrasound surveillance. The cohort in our study has substantially higher proportion of recipients with risks for developing thromboembolic complications, such as those bridged with ECMO and those transplanted for coronavirus disease (COVID)/ARDS, compared to previous literature. Another possible reason is the more liberal use of plasmaphoresis [shown to increase DVT (25)] for treatment of mild acute rejection in our institution.

Our institution’s protocol for thromboprophylasis and anticoagulation has been to place patients on prophylactic subcutaneous unfractionated heparin, and further imaging for DVT is pursued only when patients develop clinical symptoms suggestive of thrombosis. Patients who develop acute DVT, except those with active gastrointestinal (GI) or surgical site bleeding, received anticoagulation therapy. Although this study does not mandate a change in anticoagulation protocols, in our institution, we have moved away from routine anticoagulation therapy in central line related DVTs and some upper extremity DVTs, especially in those who had a difficult operation to avoid complications associated with post-operative hemothorax.

Explanations of findings

The protective effect of preoperative pulmonary hypertension likely reflects routine anticoagulation in this subgroup, reducing undetected DVT. The absence of additional mortality among DVT patients with versus without PE suggests that DVT may serve more as a marker of overall postoperative complexity rather than a direct mediator of death. Elevated mortality from bleeding underscores the narrow therapeutic window for anticoagulation in this high-risk population.

In our cohort, we found that patients who developed hemothorax or hematoma had significantly higher rates of AKI and dialysis. While our retrospective design limits causal inference, several potential mechanisms may explain this association. Intraoperative and postoperative hemorrhage often necessitates substantial blood product transfusion and re-interventions, which can lead to hemodynamic instability, low perfusion pressure, and exposure to nephrotoxic insults—all known contributors to AKI. Indeed, previous study have identified intraoperative transfusion as an independent risk factor for postoperative AKI in lung transplant recipients (26). Furthermore, Kim and colleagues reported that postoperative bleeding and PGD grade 3 were more prevalent in patients with AKI following lung (27). Wu et al. similarly demonstrated that severe bleeding during lung transplantation was associated with increased rates of dialysis and postoperative ECMO, reinforcing the link between bleeding complications and renal dysfunction (28). Collectively, these findings—and our own data—suggest a complex interplay whereby bleeding events may precipitate or exacerbate AKI in lung transplant recipients. This highlights the critical need for strategies that mitigate bleeding risk and monitor renal function closely in this vulnerable population.

Only a portion of PE cases in our cohort were attributable to documented DVT. Several mechanisms may contribute to this observation. First, because we do not perform routine duplex ultrasound surveillance, some lower-limb or pelvic DVTs may have been missed, especially in sedated or critically ill patients, thereby underestimating DVT-related PE. Second, embolic events in lung transplant recipients may arise from thrombi formed in situ within the pulmonary vasculature—either due to donorrelated thrombi or perioperative factors—rather than peripheral venous origins. For example, incidentally detected pulmonary emboli in donor lungs during procurement have been reported in 4–5% of cases and may affect recipient outcomes (29). Additionally, in situ pulmonary artery thrombosis, independent of systemic embolic origin, has been described as a complication of endothelial activation and inflammation (30). Finally, technical factors such as pulmonary vascular anastomosis—though uncommon—can predispose to localized thrombosis at the suture site or areas of stenosis or kinking (31). Taken together, these mechanisms may explain why not all PE cases in our cohort were directly linked to DVT.

Our subgroup analysis restricted to patients with DVT further clarified that mortality was driven primarily by postoperative bleeding complications rather than by PE. In multivariate analysis, hemothorax/hematoma emerged as an independent predictor of death, whereas PE did not. AKI and PGD grade 3 showed non-significant trends toward worse outcomes. These findings reinforce the concept that DVT in lung transplant recipients may act as a surrogate marker of a complicated postoperative course, with mortality influenced more by hemorrhage and multiorgan dysfunction than by embolic phenomena alone.

Implications and actions needed

Our study underscores the need for a risk-adapted thromboprophylaxis and anticoagulation strategy. Specifically, intensified clinical vigilance and selective imaging may be warranted in high-risk subgroups such as patients with lower extremity DVT or elevated platelet counts, and anticoagulation decisions should be individualized to balance thrombotic and hemorrhagic risks. Prospective multicenter studies will be essential before formal changes to prophylaxis or treatment protocols can be implemented.

Conclusions

Postoperative DVT is associated with significant mortality and a higher rate of complications, including postoperative hemothorax related to anticoagulation. Patients with lower extremity DVT and higher preoperative platelet numbers were at higher risk of developing PE compared to patients with upper extremity DVT. Thus, the anticoagulation strategy may be modified based on these risk factors to prevent bleeding associated mortality. Moreover, findings in our study further highlighted a need to develop a prospective multi-institutional study to stratify risk factors relevant to venous thromboembolism to establish a comprehensive anticoagulation strategy to reduce postoperative bleeding.

Acknowledgments

We would like to thank Ms. Elena Susan for her administrative assistance in submitting this manuscript. The abstract of this article was presented in International Society for Heart and Lung Transplantation (ISHLT) 45^th 2025 Annual Meeting.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1294/rc

Data Sharing Statement: Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1294/dss

Peer Review File: Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1294/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1294/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. This study was approved by the Institutional Review Board of Northwestern University (Nos. STU00207250 and STU00213616). The need for patient consent for data collection was waived by the institutional review board because this was a retrospective study.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Zheng M, Yousef I, Mamary AJ, et al. Venous thromboembolism in lung transplant recipients real world experience from a high volume center. J Heart Lung Transplant 2021;40:1145-52.
2. Kahan ES, Petersen G, Gaughan JP, et al. High incidence of venous thromboembolic events in lung transplant recipients. J Heart Lung Transplant 2007;26:339-44.
3. Izbicki G, Bairey O, Shitrit D, et al. Increased thromboembolic events after lung transplantation. Chest 2006;129:412-6.
4. Aboagye JK, Hayanga JWA, Lau BD, et al. Venous Thromboembolism in Patients Hospitalized for Lung Transplantation. Ann Thorac Surg 2018;105:1071-6.
5. García-Ortega A, López-Reyes R, Anguera G, et al. Venous thromboembolism in solid-organ transplant recipients: Findings from the RIETE registry. Thromb Res 2021;201:131-8.
6. Jindal RM, Sidner RA, Milgrom ML. Post-transplant diabetes mellitus. The role of immunosuppression. Drug Saf 1997;16:242-57.
7. Burdett C, Butt T, Lordan J, et al. Comparison of single lung transplant with and without the use of cardiopulmonary bypass. Interact Cardiovasc Thorac Surg 2012;15:432-6; discussion 436.
8. Peña-López Y, Machado MC, Rello J. Infection in ECMO patients: Changes in epidemiology, diagnosis and prevention. Anaesth Crit Care Pain Med 2024;43:101319.
9. Manerikar A, Watanabe S, Kandula V, et al. Indwelling Central Venous Catheters Drive Bloodstream Infection During Veno-venous Extracorporeal Membrane Oxygenation Support. ASAIO J 2022;68:859-64.
10. Kurihara C, Walter JM, Karim A, et al. Feasibility of Venovenous Extracorporeal Membrane Oxygenation Without Systemic Anticoagulation. Ann Thorac Surg ;2020110:1209-15.
11. Tomasko J, Prasad SM, Dell DO, et al. Therapeutic anticoagulation-free extracorporeal membrane oxygenation as a bridge to lung transplantation. J Heart Lung Transplant 2016;35:947-8.
12. Snell GI, Yusen RD, Weill D, et al. Report of the ISHLT Working Group on Primary Lung Graft Dysfunction, part I: Definition and grading-A 2016 Consensus Group statement of the International Society for Heart and Lung Transplantation. J Heart Lung Transplant 2017;36:1097-103.
13. K/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Am J Kidney Dis 2002;39:S1-266.
14. Rathbun S. Cardiology patient pages. The Surgeon General's call to action to prevent deep vein thrombosis and pulmonary embolism. Circulation 2009;119:e480-2.
15. Buesing KL, Mullapudi B, Flowers KA. Deep venous thrombosis and venous thromboembolism prophylaxis. Surg Clin North Am 2015;95:285-300.
16. Thrombosis: a major contributor to global disease burden. Thromb Res 2014;134:931-8.
17. Kroshus TJ, Kshettry VR, Hertz MI, et al. Deep venous thrombosis and pulmonary embolism after lung transplantation. J Thorac Cardiovasc Surg 1995;110:540-4.
18. White RH, Zhou H, Romano PS. Incidence of symptomatic venous thromboembolism after different elective or urgent surgical procedures. Thromb Haemost 2003;90:446-55.
19. Albayati MA, Grover SP, Saha P, et al. Postsurgical Inflammation as a Causative Mechanism of Venous Thromboembolism. Semin Thromb Hemost 2015;41:615-20.
20. Geerts WH, Bergqvist D, Pineo GF, et al. Prevention of venous thromboembolism: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest 2008;133:381S-453S.
21. Gordon RJ, Lombard FW. Perioperative Venous Thromboembolism: A Review. Anesth Analg 2017;125:403-12.
22. Guyatt GH, Eikelboom JW, Gould MK, et al. Approach to outcome measurement in the prevention of thrombosis in surgical and medical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest 2012;141:e185S-94S.
23. Ortel TL, Neumann I, Ageno W, et al. American Society of Hematology 2020 guidelines for management of venous thromboembolism: treatment of deep vein thrombosis and pulmonary embolism. Blood Adv 2020;4:4693-738.
24. Levy MM, Bach C, Fisher-Snowden R, et al. Upper extremity deep venous thrombosis: reassessing the risk for subsequent pulmonary embolism. Ann Vasc Surg 2011;25:442-7.
25. McGuckin S, Westwood JP, Webster H, et al. Characterization of the complications associated with plasma exchange for thrombotic thrombocytopaenic purpura and related thrombotic microangiopathic anaemias: a single institution experience. Vox Sang 2014;106:161-6.
26. Jing L, Chen W, Guo L, et al. Acute kidney injury after lung transplantation: a narrative review. Ann Transl Med 2021;9:717.
27. Kim NE, Kim CY, Kim SY, et al. Risk factors and mortality of acute kidney injury within 1 month after lung transplantation. Sci Rep 2021;11:17399.
28. Wu KA, Kim JK, Rosser M, et al. The impact of bleeding on outcomes following lung transplantation: a retrospective analysis using the universal definition of perioperative bleeding. J Cardiothorac Surg 2024;19:466.
29. Terada Y, Gauthier JM, Pasque MK, et al. Clinical Outcomes of Lung Transplants From Donors With Unexpected Pulmonary Embolism. Ann Thorac Surg 2021;112:387-94.
30. Cao Y, Geng C, Li Y, et al. In situ Pulmonary Artery Thrombosis: A Previously Overlooked Disease. Front Pharmacol 2021;12:671589.
31. Batra K, Chamarthy MR, Reddick M, et al. Diagnosis and interventions of vascular complications in lung transplant. Cardiovasc Diagn Ther 2018;8:378-86.