Thoracic endovascular repair for disseminated intravascular coagulation associated with chronic type B aortic dissection

Introduction

Chronic disseminated intravascular coagulation (DIC) is a rare complication of aortic dissection, and several treatment options have been reported.^1–4 Optimal medical therapy is recommended as the first-line approach, since patients with DIC have a risk of bleeding tendency during surgical repair. However, open and endovascular repair were selected as alternative options for uncontrollable cases. Since there are a limited number of similar reports, the best therapeutic strategy is still controversial. We present a case of DIC associated with chronic type B aortic dissection successfully treated with thoracic endovascular aortic repair (TEVAR).

Case report

A 78-year-old man was transferred to our institute because of sudden back pain. Enhanced computed tomography (CT) revealed chronic type B aortic dissection with partial thrombosis of a false lumen (from the level of diaphragm to the renal artery), extending from the distal aortic arch to the left external iliac artery (Figure 1). The primary entry was located at the distal aortic arch, and there were no findings of a malperfusion syndrome. He underwent an optimal medical treatment and discharged two weeks later. One month after discharge, he was admitted because of ecchymosis of the right groin. Laboratory examination showed anemia and DIC (hemoglobin, 6.8 g/dL; platelets, 2.8 × 10⁴/μL; D-dimer, 44.3 μg/ml; fibrinogen, 94 mg/dL), and abnormal blast cells were not observed. Transfusion and antifibrinolytic therapy was started (tranexamic acid 1500 mg/day); however, the ecchymosis and anemia reoccurred, and laboratory data did not improve. Detailed check did not detect apparent causes of DIC. We thought that the partially thrombosed false lumen was a cause of DIC, and zone 2 landing TEVAR by using Valiant Navion thoracic stent graft (Medtronic, Minneapolis, MN) with debranching from the left carotid to the left subclavian artery (7 mm PROPATEN vascular graft; W. L. Gore & Associates, Flagstaff, Ariz) was performed for primary entry closure, considering risk of paraplegia and surgical bleeding. The origin of the left subclavian artery was embolized with 14 mm AMPLATZER Vascular Plug II (Abbott Vascular, Santa Clara, CA) to prevent a type II endoleak. Angiography revealed no endoleak and retrograde type A aortic dissection.

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Figure 1.

Enhanced preoperative computed tomography shows type B aortic dissection with partial thrombosis from the distal aortic arch to the thoracoabdominal aorta (a and b).

Postoperative course was uneventful with no hemorrhagic events, and the patient was discharged on postoperative day 32 without anticoagulant therapy. Enhanced CT on postoperative day 7 showed complete thrombosis of the false lumen from the distal aortic arch to the descending aorta (Figure 2). Laboratory data associated with DIC score improved (hemoglobin, 11.7 g/dL; platelets, 6.3 × 10⁴/μL; FDP (fibrin degradation products), 18.5 mg/mL; D-dimer, 11.7 mg/mL; and fibrinogen, 191 mg/dL). Clinical time course of the patient is graphed in Figure 3.

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Figure 2.

Postoperative computed tomography showed complete thrombosis of the false lumen from the distal aortic arch to the descending aorta (a and b).

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Figure 3.

Clinical course from admission to discharge. Clinical symptoms and changes in coagulo-fibrinolytyc parameters are shown in diagrams. The status of disseminated intravascular coagulation improved and the patient became asymptomatic after thoracic endovascular aortic repair.

Discussion

Disseminated intravascular coagulation due to aortic dissection is infrequent; therefore, the frequency and mechanism are still unclear. Various approaches have been reported to be effective for chronic DIC associated with aortic dissection.^1–4 Since endoleak after endovascular repair was reported as a cause of DIC, ⁵ the indication of endovascular repair for aorta-related DIC is controversial. In general, DIC caused by aortic dissection is classified as enhanced fibrinolytic DIC, and turbulent flow in the false lumen and extensive false lumen can be a cause of DIC in a type of aortic dissection with partial thrombosis.^1,2

Optimal medical therapy with anticoagulant therapy is recommended as the first-line approach, but aorta-related DIC sometimes leads aortic extension and rupture ³ (Supplemental Table 1). Retrograde false lumen flow from the reentry was a risk of dilatation and partial thrombosis. However, simultaneous false lumen closure may be a risk of paraplegia. Therefore, we planned TEVAR for primary entry closure as the first stage and additional false lumen closure as the second stage if needed. In this case, primary entry closure can lead thrombosis of the false lumen and improve DIC status. Considering risks of bleeding in open surgery and rupture in conservative care, endovascular primary entry closure has a potential to be an effective alternative option in a case with repeated bleeding events due to DIC associated with aortic dissection.