Mass General Hospital
MAY 2012
ISSUE 47


Patent Ductus Arteriosus Endarteritis
Bojan Kovacina, MD; Jonathan Beaudoin, MD; Manavjot Sidhu, MD; Gladwin Hui, MD; Cameron Hassani, MD; Rishi Agrawal, MD; Ami B. Bhatt, MD; Suhny Abbara, MD and Brian Ghoshhajra, MD

Clinical History
A 53 year old woman presented to the emergency department with a two month history of left anterior chest pain and 5 day history of shortness of breath, bilateral calf pain and lower extremity swelling. Deep venous thrombosis was excluded by Doppler ultrasound of lower extremities. A chest CT scan was performed and demonstrated a possible patent ductus arteriosus (PDA), as well as an adjacent filling defect in the distal main pulmonary artery (PA). Transthoracic cardiac ultrasound (TTE) and cardiac CT scan (CCT) were later performed for further assessment of the possible PDA and associated filling defect in the PA.

Findings
TTE revealed a mobile mass of echoes in the lumen of the proximal left pulmonary artery (LPA), which appeared attached to the arterial wall. In addition, there was continuous color flow on the lesser curvature of the distal aortic arch and subtle continuous flow velocity just distal to the mass in the LPA, suggestive of a PDA.

CCT demonstrated a funnel-shaped arterially enhancing connection between the aortic arch and the distal main pulmonary artery, consistent with a PDA. A multi-lobulated non-enhancing filling defect was detected in the distal main pulmonary, with extension into the proximal LPA. The filling defect was attached to the arterial wall at the level of PDA.

The patient was treated with antibiotics. On a 4-week follow-up TTE (not shown), the mass of echoes decreased in size from 12 x 12mm to 7 x 12mm.


Figure 1


Figure 2


Figure 3

Figure 4

(Click on image to enlarge)

Figure 1: TTE shows a small echodensity (white arrow) at the bifurcation of the PA, extending into the proximal left pulmonary artery.

Figure 2,3:
Arterial-phase oblique-sagittal or candy-cane plane (2) and delayed-phase axial (3) cardiac CT scan demonstrates multilobulated non-enhancing filling defect (white arrows) in the distal PA and proximal LPA, attached to the superior wall of the artery. Triangular contrast-filled connection between aorta and the PA is noted at the site of the attachment of the defect (black arrow), consistent with PDA.

Figure 4:
Contrast enhanced CT scan of the chest (performed earlier) demonstrates a small streak of contrast within the PA (black arrow) adjacent to the filling defect, suggesting PDA with a small aortic-to-PA shunt.


Discussion
In this case, the presence of a PDA, lack of enhancement of the mass on delayed CCT and decrease in size of the mass following antibiotics treatment favor the diagnosis of PDA endarteritis/endocarditis. Differential diagnosis includes metastasis and angiosarcoma, although these entities are less likely as they typically show enhancement on delayed CCT or cardiac MRI (not performed in this case) , have no relation to PDA, should not decrease in size without targeted treatment and usually are more distal (metastasis).

PDA endarteritis (also referred to as PDA-related endocarditis) is a rare entity with an estimated annual risk of 0-45% in patients with PDA. Both infective (IE) and non-bacterial (NBE) endocarditis/endarteritis have been described. Although wide use of antibiotics decreased the incidence and mortality of IE, this entity has remained a potentially fatal event in patients with PDA. NBE (also called marantic endocarditis) is characterized by deposition of sterile fibrin and platelet aggregates at the sites of microscopic injury to the endothelium of the PA, which may be caused by turbulent blood flow secondary to the PDA. Several conditions have been associated with NBE, including circulating immune complexes, disseminated intravascular coagulopathy and carcinomatosis.


REFERENCES
1.

Kouris NT, Sifaki MD, Kontogianni DD, et al. Patent ductus arteriosus endarteritis in a 40-year old woman, diagnosed with transesophageal echocardiography. A case report and brief review of the literature. Cardiovascular ultrasound. 2003;1:2

2. Song H, Liu F, Dian K, Liu J. Intraoperative transesophageal echocardiography-guided patent ductus arteriosus ligation in an asymptomatic nonbacterial endocarditis patient. Anesthesia and analgesia. 2010;111:878-880
3. Asopa S, Patel A, Khan OA, Sharma R, Ohri SK. Non-bacterial thrombotic endocarditis. European Journal of cardio-thoracic surgery. 2007; 32: 696-701

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