Abstract:
Pulmonary artery pseudoaneurysms are a rare but potentially lethal
diagnosis. They can be further categorized by etiology or location and
are typically successfully treated with endovascular therapies. However,
they occasionally require operative intervention. Here, we present a
case of a patient who presented with a central pulmonary artery
pseudoaneurysm on CT scan with unclear etiology that was initially
treated with conservative management. However, this was noted to have
rapid enlargement on interval imaging necessitating urgent surgical
intervention. The patient underwent a median sternotomy, anterior
pulmonary artery arteriotomy for exposure, exclusion of the posterior
artery pseudoaneurysm with a bovine pericardial patch, and closure of
the anterior arteriotomy with a bovine pericardial patch. The patient
did well and was discharged on postoperative day eleven with repeat
imaging showing resolution.
Introduction
Pulmonary artery pseudoaneurysms (PAPs) are a rare but potentially
life-threatening disease1. PAPs can be defined as
congenital, such as inherited connective tissue abnormalities, or
acquired, such as infectious causes1,2,3. Clinical
presentation ranges from asymptomatic cases to massive hemoptysis with
hemorrhagic shock1,2,3. PAPs can be characterized as
central or peripheral on CT angiography (CTA). There are currently no
consensus guidelines for the management of PAPs4. Most
PAPs are amenable to endovascular treatment with embolization or
stenting; however, indications for operative repair include large size,
hemorrhage, or medically refractory infections. These usually require an
aneurysm resection and often an associated pulmonary
resection2,4,5. Here we present a case of central PAP
with unclear etiology that was treated with median sternotomy and
exclusion of the pseudoaneurysm with a pericardial patch.
Case report
A 52-year-old female presented with chest pain, cough, and shortness of
breath over several months. The patient had been evaluated on multiple
occasions with an unrevealing work up including an CTA that was normal.
However, due to persistent symptoms, a CTA was repeated several weeks
later which identified a mediastinal fluid collection and an esophagram
showing a contained mid-thoracic esophageal leak. A multidisciplinary
team including cardiothoracic surgery, pulmonology, and interventional
radiology was convened. Initially, an esophageal stent was considered.
However, given the patient’s clinical improvement, the patient was
medically managed, and a repeat CTA and esophagram showed a decreased
size of mediastinal collection and resolution of the esophageal leak.
She was therefore discharged on oral antibiotics.
She represented five days later with worsening symptoms. A CTA showed an
increase in the size of the mediastinal collection with mass effect on
the adjacent right mainstem bronchus, as well as a new 8x5 mm right
sided central posterior wall PAP (Figure 1) . The same
multidisciplinary team recommended further work up for malignancy given
the enlarging mass despite antibiotic therapy. This consisted of an
esophagogastroduodenoscopy and bronchoscopy with ultrasound. Tissue
samples obtained were non diagnostic and final pathology demonstrated no
malignant cells. An interval CTA, performed two days later to monitor
the PAP, demonstrated a significant increase in size to 19x28 mm(Figure 1) .
Given the enlarging PAP and concern for rupture, it was determined that
the patient needed urgent surgical therapy. She underwent a median
sternotomy, was placed on cardiopulmonary bypass, and the right
pulmonary artery (PA) was exposed. The posterior right PA artery was
encased in a dense mass, which was biopsied. Due to the inflammatory
process, we elected to repair the pseudoaneurysm from within the
pulmonary artery rather than resecting and replacing the involved
vessel. A longitudinal anterior right pulmonary arteriotomy was
performed with a 1.5 cm perforation noted in the posterior wall(Figure 2). A bovine pericardial patch was sutured around the
borders of the PAP, effectively excluding it from the main PA lumen(Figure 2). The anterior arteriotomy was closed with another
bovine pericardial patch to avoid stenosis. Multiple intraoperative
tissues samples were sent to evaluate for malignancy with non-diagnostic
results from pathology. The patient was weaned off cardiopulmonary
bypass, for a total time of 126 minutes, and the sternum was closed.
The patient’s post-operative course was uneventful. She was extubated on
postoperative day one and discharged on post-operative day eleven on
intravenous antibiotics. The patient’s symptoms have since resolved
since discharge, with interval imaging showing resolution of the right
PAP as well as the mediastinal collection.
Discussion
In this case we present a unique presentation and management strategy
for a PAP. The patient had imaging studies that showed an esophageal
leak and a mediastinal collection with subsequent mass effect and new
PAP concerning for a neoplastic versus infectious process. All attempts
to elucidate the etiology were unsuccessful as pathological and
microbiological data were unrevealing. Given the unique finding of a
central PAP with rapid expansion, urgent operative surgical intervention
was performed because of the risk of rupture. Intraoperatively, given
the posterior location of PAP and adjacent mediastinal mass, a right
anterior pulmonary arteriotomy provided optimal exposure (Figure
2) . The PAP was excluded with bovine pericardial patch, which lead
resolution of the PAP on post-operative CTA. No pulmonary resection was
required. Finally, the patient’s PAP was likely caused by an infection,
as the mediastinal collection resolved after antimicrobial therapy;
however, the causative organism as well as the cause for esophageal
perforation was never identified.
Conclusions
Central pulmonary artery pseudoaneurysms are rare and can be safely
treated with pulmonary artery arteriotomy and bovine patch exclusion.