Bilateral EKOS catheter thrombolysis of acute bilateral pulmonary embolism in a hemodynamically unstable patient

Case Report

Bilateral EKOS catheter thrombolysis of acute bilateral pulmonary embolism in a hemodynamically unstable patient


Pulmonary embolism is a common and sometimes devastating disease caused by many factors most com- monly deep venous thrombosis. Treatment is typically systemic anticoagulation depending on patient clinical presentation. For patients with life-threatening pulmonary embolism, intravenous tissue plasminogen activator (Acti- vase; Genentech, South San Francisco, Calif) is the most common medication given emergently at the time of presentation. computed tomographic angiography of the chest has advanced the diagnosis and potential treatment options for patients with life-threatening pulmonary embolism. Combination of percutaneous transcatheter- directed pharmacologic and mechanical thrombolysis has become extremely useful in these difficult cases.

Our patient is a 63-year-old man with medical history of deep venous thrombosis who presented to the emergency department with bilateral massive pulmonary emboli. The patient was in shock, with an admitting blood pressure of 60/

40 mm Hg and renovascular hypoperfusion resulting in a creatinine level of 1.9 (g/dL). An emergent echocar- diography was obtained and demonstrated a large filling defect within the right ventricle in the region of the pulmonary outflow tract (Fig. 1). The echocardiogram also reported severe Right ventricular hypertrophy, a right ventricular pressure of 46 mm Hg (nl. 25 mm Hg) and normal left ventricular function. The patient was given intravenous (IV) bolus of tissue plasminogen activator according to the American College of Chest Physicians (ACCP) recommendation for massive pulmonary embolism. Thirty milligrams of IV tPA was administered before the patient leaving the emergency room to go directly to our interventional radiology suite for Endovascular therapy. In the suite, a conventional bilateral pulmonary arteriogram was obtained, demonstrating bilateral large pulmonary emboli resulting in complete occlusion of the left upper lobe and almost the entire right lung (Figs. 2 and 3). Using standard interventional technique, bilateral EKOS Endowave device catheters (EKOS Corporation, Bothell, Wash) were placed in

good position within the right and left pulmonary arteries (Fig. 4). Tissue plasminogen activator was initiated at 0.5 mg/h through each catheter. This was allowed to infuse more than 8 hours, and a repeat bilateral pulmonary angiogram was performed the next morning. Fibrinogen levels were monitored every 4 hours during the infusion therapy. There was a complete clearing of the bilateral pulmonary emboli after combination EKOS/tPA thrombolysis (Fig. 5). The patient had clinically improved by the morning with normalized blood pressure and no oxygen requirements. There were no Bleeding complications after EKOS thrombo- lysis. He was discharged from the intensive care unit to the floor that day and was discharged to home in 3 days.

Venous thrombosis embolism is the third most common vascular disease. The incidence continues to increase, and there is an estimated greater than 600 000 cases per year [1]. The disease can be undiagnosed resulting in a mortality of up to 30%. With development in cardiopulmonary imaging such as computed tomographic angiography, we are able to identify pulmonary emboli quickly and efficiently. The clinical presentation and radiographic correlation performed in the emergency room setting makes the diagnosis very

Fig. 1 ECHO showing clot in right venticle adjacent to pulmonary outflow tract.

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983.e6 G.W. Stambo, B. Montague

Fig. 2 Right pulmonary angiogram showing the extensive pulmonary embolism involving almost the entire pulmonary tree.

Fig. 4 Bilateral EKOS catheter placed inboth right and left pulmonary arteries (see arrows).

quickly allowing for treatment to proceed as soon as possible. Patients with massive pulmonary embolism and hemodynamic instability may receive 100 mg IV tPA according to the ACCP recommendations [2,3]. Our patient was given a fraction of the typical dosage of tPA while preparing for transport to our department. He did not fail IV tPA therapy but was quickly triaged to our department. Based on many previous cases of large pulmonary emboli seen in our institution, the patient was routed directly to our laboratory after consultation with all pertinent specialists. When sent directly to us from the emergency room, we have had great success with percutaneous therapies. The manage- ment for pulmonary emboli for hemodynamically significant Clot burden has typically been systemic anticoagulation and possible open surgical embolectomy [4]. However, a select group of patients can now benefit from percutaneous

transcatheter thrombolysis directly into the pulmonary arteries [1,4]. Furthermore, many mechanical and pharma- cologic thrombolysis options are now available including the AngioJet catheter (Possis Medical, Minneapolis, Minn) using the power-pulse technique and now EKOS endowave ultrasound enhanced thrombolysis device.

In our laboratory, we have used EKOS extensively with great results in cases ranging from peripheral vascular, intracerebral, and pulmonary vasculature. We have per- formed many cases with Mechanical thrombectomy over the years. We felt that these combined therapies would improve the patients overall outcome with complete clot lysis compared with fragmenting the big clots and dispersing them into the remainder of the peripheral pulmonary branches. His creatinine was 1.9 at admission, which suggested a renal hypoperfusion. The attending cardiologist

Fig. 3 Left pulmonary angiogram showing extensive pulmonary embolism involving the left pulmonary artery.

Fig. 5 Completion bilateral pulmonary arteriogram showing complete clearing of the clot.

Case Report 983.e7

performed an emergent echocardiogram at the bedside negating the need for a computed tomographic angiography. The selected image was a portion of a complete study demonstrating clot in the right ventricle and extending into the pulmonary outflow tract. Based on his renal functions, we continued aggressive IV hydration and diluted our contrast during the procedure for a total of 60 mL for the entire procedure. Our conventional pulmonary angiogram then confirmed the bilateral massive pulmonary embolism suspected on the echocardiogram. It was not known if the patient had previous pulmonary embolism in the past but, in light of the patient’s previous deep vein thrombosis subclinical pulmonary embolism, would have contributed in his right ventricular hypertrophy, and elevated right ventricular pressures made worse by the massive acute clot burden. Over the course of his hospital admission, his creatinine level drifted down to a discharge level of

1.4 g/dL despite undergoing 2 pulmonary angiograms.

In our practice, most patients with pulmonary embolism follow the standard ACCP guidelines for treatment and not our candidates for percutaneous therapies. However, those extraordinary cases like this have routinely been transferred to our laboratory to help clear the large clot burden with either percutaneous thrombectomy or catheter- directed thrombolysis. The EKOS catheter is a mechanical thrombolysis catheter that uses acoustic microstreaming and ultrasonic agitation to make clot more susceptible to clot dissolving medications. This accelerates lysis of the clot for improved clot dissolution and rapid vessel patency. Instead of numerous hours to days of thrombolytic infusion therapy while in the intensive care unit as in the past, this catheter along with the new thrombolytic drugs like tPA or TNK (Tenecteplase; Genentech, South San Francisco, Calif) can significantly reduce infusion times improving patient’s clinical status rapidly and with less chance of bleeding complications from the drug [5]. Complete

clearing of the bilateral thrombus the next day corre- sponded with the patients’ improved status resulting in an excellent clinical and radiographic response. Although this technique is slower than Surgical thrombectomy, there are far less risks. As in our patient, there were no bleeding complications noted and is typical of this device. We believe that the addition of the EKOS ultrasonic thrombo- lytic catheter system along with the newer thrombolitic agents can help interventional specialists improve patient’s outcome with hemodynamically unstable massive pulmo- nary embolism.

Glenn W. Stambo MD Brian Montague MD

SDI Radiologists, Department of Vascular and

Interventional Radiology St. Joseph’s Hospital and Medical Center

Tampa, FL 33603, USA

E-mail address: [email protected] doi:10.1016/j.ajem.2009.12.023


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  4. Loban DG, Cronin CG, Meehan CP, Kee ST, Dake MD, Davidson IR, et al. Massive pulmonary embolus with Hemodynamic compromise: therapeutic options. Emerg Radiol 2006;13:161-9.
  5. Marchigiano G, Riendeau D, Morse CJ. New technology applications: thrombolysis of acute deep vein thrombosis. Crit Care Nurs Q 2006: 312-22.

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