Management of Massive Pulmonary Embolism with Clot in Transit Using Fluoroscopic and Transthoracic Echocardiographic-Guided Large-Bore Mechanical Thrombectomy

Massive pulmonary embolism (PE) is a life-threatening condition caused by the obstruction of pulmonary arteries requiring precise and timely intervention to prevent mortality. Clots in transit (CIT), which are thrombi traveling through the right heart, pose a unique challenge due to their high risk of embolization to the pulmonary arteries. The treatment of massive PE, particularly in the presence of CIT, demands careful consideration of the patient's clinical status and contraindications to standard therapies like thrombolysis. In this case, we present the use of fluoroscopy and transthoracic echocardiography (TTE) for real-time guidance during large-bore mechanical thrombectomy (LBMT) to remove right ventricle (RV) thrombi.

A 67-year-old male with a history of chronic obstructive pulmonary disease on home oxygen and recent intracranial bleeding presented with acute dyspnea, hypoxia, and sustained hypotension. His vital signs were significant for a mean arterial pressure of 58 and an oxygen saturation of 84% on 6 L oxygen. Laboratory findings were noticeable for elevated troponin and lactic acid. Computed tomography angiography of the chest confirmed bilateral pulmonary emboli with RV dilation and interventricular septal deviation. TTE revealed CIT ([Figs. 1] and [2]) in the right heart along with severe RV dysfunction. Given the patient's hemodynamic instability, transesophageal echocardiography (TEE) was avoided to reduce sedation risks, and TTE was utilized for real-time imaging. Due to contraindications for thrombolysis related to recent intracranial bleeding, LBMT was performed, successfully removing the CIT under fluoroscopic and TTE guidance ([Fig. 3]). Postprocedural imaging confirmed thrombus resolution ([Fig. 4]), normalization of RV function, and hemodynamic stabilization.

Fig. 1 Transthoracic echocardiography (TTE) demonstrating a clots in transit (CIT) within the right atrium (RA) and right ventricle (RV).

Fig. 2 Transthoracic echocardiography (TTE) demonstrating a clearer view of the clots in transit (CIT) in the right atrium (RA).

Fig. 3 Transthoracic echocardiography (TTE) with aspiration catheter positioned within the right ventricle (RV). TTE showing mobile echogenic clots in transit (CIT).

Fig. 4 Postop transthoracic echocardiography (TTE) showing complete removal of right ventricle (RV) thrombi.

CIT is a critical condition that requires immediate intervention due to its association with high mortality rates. It is frequently linked to massive PE, where prompt management is crucial to prevent further embolization and hemodynamic collapse. Treatment options for CIT include systemic thrombolysis (ST), catheter-based thrombectomy (CBT), surgical embolectomy, and anticoagulation (AC) alone.[1] [2]

ST remains a common intervention for PE and CIT due to its rapid fibrinolytic effects; however, it is often contraindicated in patients with a recent history of major bleeding, such as intracranial hemorrhage, due to the elevated risk of hemorrhagic complications.[3] While effective, surgical embolectomy is more invasive and associated with higher mortality and morbidity compared to less invasive options.[1] [2] AC alone is another management option but carries the highest mortality rate among all treatment strategies.[1] [2]

CBT, particularly LBMT, offers a minimally invasive alternative for managing CIT and is a promising approach for high-risk patients.[1] [2] [4] The PEERLESS trial compared LBMT and catheter-directed thrombolysis (CDT), demonstrating that LBMT achieves reduced rates of clinical deterioration and postprocedural intensive care unit stays compared to CDT, without significant differences in mortality or bleeding risk.[4] Furthermore, a meta-analysis found that CBT, including LBMT, has lower overall mortality rates compared to AC alone or surgical embolectomy, further supporting its role in CIT management.[1]

In this case, LBMT was selected due to the patient's recent intracranial bleeding, which contraindicated thrombolysis, and the need for a rapid and effective intervention to address hemodynamic instability.[3] TTE played a pivotal role in the success of the procedure, providing real-time imaging that allowed for precise catheter placement and continuous monitoring of cardiac function throughout the intervention. Unlike TEE, which requires sedation and may exacerbate hemodynamic instability, TTE offered a safer alternative in this critically ill patient. Its noninvasive nature allowed for the successful removal of the clot, restoration of right ventricular function, and hemodynamic stabilization.

This case demonstrates the importance of TTE in guiding LBMT, offering minimally invasive and effective treatment for high-risk CIT patients. TTE's real-time imaging capabilities and noninvasive nature make it a valuable tool in critically ill patients, particularly when sedation for TEE is contraindicated. While LBMT guided by TTE offers a promising alternative for high-risk patients, further research is necessary to establish standardized protocols. Comparative studies should focus on optimizing the integration of imaging modalities like TTE in procedural planning and evaluating the long-term outcomes of LBMT versus other treatment modalities. Such efforts will refine treatment guidelines and advance care for patients with CIT.

Conflict of Interest

None declared.

Note

An abstract based on this case report has been submitted to the Pan Arab Interventional Radiology Society (PAIRS) conference and is currently pending approval.

Authors' Contribution

M.M.S.: Primary author, drafted and revised the manuscript, and coordinated submission. O.A.: Assisted with manuscript writing and reviewed clinical content. A.K.: Supervised the clinical content, provided expert guidance, and reviewed the final manuscript.

• References

• 1 Maqsood MH, Zhang RS, Zlotnick DM, Parikh SA, Bangalore S. Outcomes with treatment interventions for clot-in-transit in patients with pulmonary embolism: a meta-analysis. J Invasive Cardiol 2024; 36 (09)
• 2 Zhang RS, Yuriditsky E, Zhang P. et al. Comparing management strategies in patients with clot-in-transit. Circ Cardiovasc Interv 2024; 17 (08) e014109
• 3 Kearon C, Akl EA, Comerota AJ. et al. Approach to thrombolytic (fibrinolytic) therapy in acute pulmonary embolism: patient selection and administration. . In: Connor RF, ed. UpToDate. Wolters Kluwer. Accessed November 20, 2024; available at: https://www.uptodate.com/contents/approach-to-thrombolytic-fibrinolytic-therapy-in-acute-pulmonary-embolism-patient-selection-and-administration
• 4 Jaber WA, Gonsalves CF, Stortecky S. et al; PEERLESS Committees and Investigators. Large-bore mechanical thrombectomy versus catheter-directed thrombolysis in the management of intermediate-risk pulmonary embolism: primary results of the PEERLESS randomized controlled trial. Circulation 2024;

Publication History

Article published online:
24 March 2025