Internal mammary artery pseudoaneurysms complicating chest wall

infection in children

Diagnosis and endovascular therapy

Hemant Deshmukha, Srinivasa R. Prasadb,*, Tufail Patankara, Madhavi Zankara

aDepartment of Radiology, King Edward Memorial Hospital, Bombay, IndiabDepartment of Abdominal Imaging, 9th Floor, Mallinckrodt Institute of Radiology, St. Louis, MO 63110, USA

Received 3 April 2001; accepted 2 June 2001

Abstract

Mycotic internal mammary artery (IMA) pseudoaneurysms are sparsely reported in medical literature. We report imaging findings of IMA

pseudoaneurysms secondary to chest wall abscesses (staphylococcal and tuberculous) in two children. Both children were successfully

treated by endovascular method thus obviating the need for surgery. D 2001 Elsevier Science Inc. All rights reserved.

Keywords: Abscess; Internal mammary artery; Pseudoaneurysm; Embolization

1. Introduction

Internal mammary artery (IMA) aneurysms are extremely

rare. Postoperative [1], posttraumatic, mycotic [2], and

atherosclerotic aneurysms of the IMA are described in the

literature. IMA may be a source of significant mediastinal

hemorrhage with possible catastrophic consequences espe-

cially in patients with blunt or penetrating trauma [3].

Angiographic demonstration of an aneurysm is critical in

establishing specific diagnosis and detects the source of

hemorrhage to enable timely institution of endovascular

treatment. We report two cases of bleeding IMA pseudoa-

neurysms in children (staphylococcal and tuberculous pseu-

doaneurysms) that were successfully embolized using coils.

2. Case reports

2.1. Case 1

A 5-year-old boy developed fever and a large, left-sided

anterior chest wall abscess 1 week following an accidental

fall from a treetop. Incision and drainage of this abscess in a

peripheral hospital had yielded blood admixed with pus and

had resulted in considerable hemorrhage. The pus had

grown Staphylococcus aureus and the patient was put on

antistaphylococcal antibiotics. The patient was referred to

our hospital following two episodes of massive hemoptysis.

Clinical examination revealed a large, anterior chest wall

abscess. Contrast-enhanced CT scan of the chest demon-

strated a large, partially thrombosed pseudoaneurysm; how-

ever, its precise arterial origin could not be ascertained

(Fig 1). In addition, there was a lenticular-shaped hemo-

thorax. Arch aortogram, bronchial, and intercostal angio-

grams were normal. Selective left subclavian angiogram

showed a large pseudoaneurysm arising from the IMA just

distal to its origin (Fig. 2a). Complete occlusion of the IMA

at its origin with obliteration of the pseudoaneurysm was

achieved using 4-mm diameter, 3-cm-long steel coil (Cook,

Bloomington, US) placed through a 4F head hunter (Cook)

(Fig. 2b). A follow-up CT scan at 2 weeks showed marked

diminution in the size of the pseudoaneurysm. The patient

was discharged after 2 weeks following an uneventful

course in the hospital.

2.2. Case 2

An 11-year-old girl presented with low-grade fever and a

right-sided anterior chest wall cold abscess. An incision and

drainage was attempted in a peripheral hospital resulting in

0899-7071/01/$ – see front matter D 2001 Elsevier Science Inc. All rights reserved.

PII: S0899 -7071 (01 )00325 -4

* Corresponding author.

E-mail address: sprasad@partners.org (S.R. Prasad).

Journal of Clinical Imaging 25 (2001) 396–399

significant bleeding. Hemostasis was achieved by surgical

packing of the wound. The patient was then referred to our

hospital. Doppler sonography of the chest demonstrated a

large pseudoaneurysm in the bed of the chest wall abscess

(Fig. 3). Acid-fast bacilli were identified in the pus by Ziehl–

Nielsen staining (the cultures were positive for Mycobacte-

Fig. 1. (Case 1) Contrast-enhanced CT scan of the chest shows a large,

partially thrombosed aneurysm (arrow).

Fig. 2. (Case 1) (a) Delayed phase of left subclavian angiogram demonstrates the lumen of the pseudoaneurysm (curved arrow). Note opacification of the left

upper and mid zones and the marked deviation of the esophageal Ryle’s tube to the right (arrow). (b) Postembolization left subclavian angiogram shows

complete occlusion of the IMA and the pseudoaneurysm. Arrow shows the coil at the origin of the IMA.

Fig. 3. (Case 2) Chest ultrasound showing the pseudoaneurysm (straight

arrows) in the bed of tuberculous cold abscess (curved arrows). AO: Aorta.

H. Deshmukh et al. / Journal of Clinical Imaging 25 (2001) 396–399 397

rium tuberculosis 4 weeks later). Arch aortogram, bronchial,

and intercostal angiograms did not show any abnormality.

Selective right subclavian angiogram showed a large pseu-

doaneurysm arising from the IMA and having dual supply

(Fig. 4a). A 4F head hunter was reshaped to engage the

origin of the IMA. Four platinum Hilal embolization coils

(Cook) of 5-mm diameter, 1-cm-long dimensions were

placed in both IMA divisions and in the IMA proximal to

its bifurcation. Postembolization selective right IMA angio-

gram showed complete obliteration of the IMA proximal to

the pseudoaneurysm with reflux of contrast into the subcla-

vian artery (Fig. 4b). The patient was started on antitubercu-

lous chemotherapy. A Doppler sonogram at the end of

3 months revealed no Doppler signals within the pseudoa-

neurysm suggesting successful vaso-obliteration. There was

a remarkable decrease in the size of the cold abscess and the

anterior chest wall wound had healed.

3. Discussion

IMA, being unusually resistant to typical (nontraumatic)

arterial pathologies, is an uncommon target site for aneur-

ysm formation [4]. IMA aneurysms have been reported

secondary to trauma, surgery [1], vasculitis [4], invasive

chest wall aspergillosis [2], fibromuscular hyperplasia, and

rarely atherosclerotic disease [4]. Aneurysms of the IMA are

frequently symptomatic, though occasionally may present as

an asymptomatic anterior mediastinal mass. Patients usually

present with hemoptysis [4], bulging chest mass, cough, or

occasionally dyspnea due to hemothorax.

Mycotic pseudoaneurysms secondary to chest wall infec-

tion have been documented in Ref. [2]. Sanchez et al. [2]

reported a mycotic IMA pseudoaneurysm secondary to

invasive aspergillosis in a patient with chronic granuloma-

tous disease. In our first patient, the close proximity of the

IMA with the chest wall abscess had led to the formation of

the pseudoaneurysm. Further traumatic insult in the form of

abscess drainage may have contributed to the growth of the

pseudoaneurysm. We believe that the IMA pseudoaneurysm

in our second patient was secondary to tuberculous cold

abscess. Encapsulation of liquefied caseous tuberculous pus

results in cold abscess [5]. Majority of chest wall cold

abscesses is secondary to tuberculous lymphadenitis of the

intercostal lymph nodes; osteomyelitis of the vertebrae, ribs,

and sternum accounts for the rest [5]. Contiguous involve-

ment of the nearby vessels contributes to the development of

pseudoaneurysms. We did not find mention of tuberculous

pseudoaneurysm of IMA in English literature.

Aortography and subclavian angiogram are valuable in

evaluating the etiology of anterior chest wall and mediastinal

hemorrhage [6]. If the thoracic aortogram is normal, IMA

and intercostal angiograms are warranted to demonstrate the

source of bleeding [6]. Documentation of IMA aneurysms by

selective angiogram is an important prerequisite to sub-

sequent treatment. Since the origin of the IMA is at an acute

angle from the subclavian artery, stable and safe catheter

position can be achieved either by placing preshaped cath-

eters or by employing coaxial catheterization technique.

Fig. 4. (Case 2) (a) Selective right IMA angiogram demonstrating the

pseudoaneurysm with dual supply (arrow). (b) Postembolization right IMA

angiogram showing complete obliteration of the pseudoaneurysm with

reflux of contrast into the subclavian and vertebral arteries (arrow shows the

coils within the IMA).

H. Deshmukh et al. / Journal of Clinical Imaging 25 (2001) 396–399398

Embolization of the IMA has been reported for the

control of traumatic and tumoral hemorrhage. Embolo-

therapeutic occlusion of the IMA has been performed using

various embolic materials such as gelfoam [6], autologous

clots [7], Gianturco coils [3], and absolute alcohol [8].

Potential complications of the procedure include inadvertent

embolization of the vertebral or subclavian arteries that can

be avoided by stable and selective catheter placement and

cautious embolization [6]. Rich collateral vascular supply

excludes the possibility of chest wall infarction after select-

ive embolization. Retrograde collateral flow to the bleeding

site can be prevented by injecting particulate embolic

material into the IMA distal to the arterial pathology [6].

In our two patients with staphylococcal and tuberculous

pseudoaneurysms complicated by trauma, coil embolization

of the IMA resulted in total obliteration of the pseudoaneur-

ysms. Complete control of hemoptysis was achieved, thus

obviating the need for emergency thoracotomy and its

attendant complications. Endovascular treatment of the pseu-

doaneurysms combined with antibiotics ensured cure of the

pseudoaneurysms and healing of the chest wall abscesses.

In conclusion, IMA pseudoaneurysms, though distinctly

rare, may contribute to life-threatening hemorrhage. Anterior

chest wall abscesses should be treated aggressively to

prevent transthoracic spread of infection leading to vascular

complications. Percutaneous transcatheter vaso-occlusion of

the IMA pseudoaneurysm is a safe, effective, and minimally

invasive nonsurgical means of achieving cure.

References

[1] Millner RW, Guvendik L, Blauth C, Treasure T, Pepper JR. False

aneurysm of the right internal mammary artery. Ann Thorac Surg

1991;51(5):831–2.

[2] Sanchez FW, Freland PN, Bailey GT, Vujic I. Embolotherapy of a

mycotic pseudoaneurysm of the internal mammary artery in chronic

granulomatous disease. Cardiovasc Intervent Radiol 1985;8:43–5.

[3] Smith DC, Senac MO, Bailey LL. Embolotherapy of a ruptured internal

mammary artery secondary to blunt chest trauma. J Trauma 1982;

22:333–5.

[4] Giles JA, Sechtin AG, Waybill MM, Moser RP. Bilateral internal mam-

mary artery aneurysms: a previously unreported cause for anterior me-

diastinal mass. Am J Roentgenol 1990;154:1189–90.

[5] Hurt RL. The thorax. In: Mann CV, Russell RCG, editors. Love and

Bailey’s short practice of surgery. 21st ed. London: ELBS with Chap-

man & Hall, 1994. p. 831.

[6] Husted JW, Stock JR, Manella WJ. Traumatic anterior mediastinal

hemorrhage: control by internal mammary artery embolization. Cardi-

ovasc Intervent Radiol 1982;5:268–70.

[7] Harrington DP, Barth KH, Baker RR, Truax DT, Abeloff MD, White

RI. Therapeutic embolization for hemorrhage from locally recurrent

cancer of the breast. Radiology 1978;129:307–10.

[8] McLean GK, Mackie JA, Hartz WH, Freidman DB. Percutaneous al-

cohol injection for control of internal mammary artery bleeding. Am J

Roentgenol 1983;141:181–2.

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