Keywords
aneurysm - reoperation - congenital heart disease - aorta
Introduction
Pseudoaneurysm of the thoracic aorta after previous surgery (aortic surgery and aortic
valve replacement) is a rare and life-threatening condition.[1]
Herein, we report our surgical management of a neoaortic pseudoaneurysm with transsternal
penetration as part of 6th redo in a patient with the history of hypoplastic left
heart syndrome (HLHS).
The patient's legal guardian provided written informed consent for this case report.
Case Description
A 23-year-old male patient was referred to our cardiac surgery department with the
suspected diagnosis of mediastinal abscess, after deterioration of general condition,
fever, and pressure-dolent parasternal swelling had led to external hospital admission.
The patient, born with HLHS, had previously undergone five cardiac operations at our
center: Norwood operation, aortic arch patch plastic as treatment of residual aortic
arch stenosis, hemi-Fontan with aorta-pulmonary shunt, Fontan completion, and replacement
of the ascending aorta as treatment of false aneurysm. Additionally, the patient had
undergone stent implantation at the upper cavopulmonary anastomosis and fenestration
of the extracardial conduit. Occlusion of superior vena cava as well as statomotor
and psychomotor retardation and condition after perioperative stroke were among his
secondary diagnoses.
Positron emission tomography-computed tomography (CT) diagnosis revealed enhancement
in the presternal and sternal area, as well as at the aortic prosthesis. An extravasate
at the distal anastomosis of the ascending aorta prosthesis with a large pre- and
retrosternal hematoma was ultimately revealed in CT angiography ([Fig. 1]) and echocardiography. Therefore, the indication for surgery was given.
Fig. 1 Computed tomography (CT) angiography showing an extravasate at the distal anastomosis
of the ascending aorta prosthesis with a large hematoma in suspected communication
with presternal space (marked with asterisk). (A) Transversal view, (B) sagittal view.
Arterial cannulation was established with a 17-Fr cannula through a 7-mm Intergard
prosthesis (Getinge, Rastatt, Germany) in the right femoral artery. Venous drainage
was achieved through a 21-Fr femoral cannula. Additional arterial cannulation of the
right subclavian artery with an 18-Fr cannula through a 7-mm prosthesis was necessary
to achieve an adequate flow on extracorporeal circulation (ECC) and selective antegrade
cerebral perfusion (SACP). After cooling to 18°C while performing partial inferior
sternotomy and careful preparation of the system ventricle, ECC was switched to minimal
flow in head-down position and sternotomy was completed using an oscillatory saw.
Here, it was noted, that the presternal, 4 × 5 cm large hematoma was connected with
the retrosternal left para-aortic space through a 1-cm defect in the sternal corpus
([Fig. 2A]). After reestablishment of body weight corresponding ECC flow, the brachiocephalic
trunk was exposed and snared. A large hematoma in the retrosternal, para-atrial space
was evacuated. In the wake of evacuation, an arterial bleeding at the distal aortic
prosthesis took place. Retrograde ECC was stopped and antegrade ECC was switched to
unilateral SACP under near-infrared spectroscopy control. Exposure of the ascending
aortic 22-mm Dacron prosthesis showed a semicircular dehiscence at the distal anastomosis
with the aortic arch. The prosthesis was removed with proximal and distal postresection.
Histidine-tryptophan-ketoglutarate cardioplegia was applied to the heart already arrested
by deep hypothermia through the coronary ostia. The valve of the system ventricle
appeared tricuspid and showed no signs of degeneration or endocarditis. A 24-mm Vascutek
prosthesis (Terumo, Inchinnan, United Kingdom) was implanted ([Fig. 2B]). After 44 minutes, whole body perfusion was recommenced. After warming of the patient
and defibrillation of the system ventricle, ECC was successfully weaned under low
catecholamine dosage after 248 minutes of ECC time. Pericardial closure was performed
with a Gore-Tex patch and primary chest closure could be performed.
Fig. 2 Surgical result after Vascutek prosthesis implantation in neoaorta (prosthesis marked
with arrow), note the 1-cm defect in the sternal corpus after evacuation of hematoma
(marked with asterisk), (A) cranial view; (B) surgical view.
Intensive care unit stay was prolonged due to impaired gas exchange in need of continuous
positive airway pressure therapy as a result of a preknown plastic bronchitis and
due to statomotor and psychomotor retardation of the patient. A paralytic ileus was
successfully treated with propulsive measures. In the aortic explant, Bacillus cereus was identified. Hence, an antibiotic therapy with vancomycin for 4 weeks, followed
by clindamycin treatment for 2 weeks was performed as recommended by the antibiotic
stewardship team of our center.
CT and echocardiography control imaging 1 year after surgery was unobtrusive ([Fig. 3]).
Fig. 3 Unobtrusive control computed tomography (CT) scan 1 year after surgery (ascending
neoaorta marked with asterisk), (A) transversal view, (B) sagittal view.
Three years from surgery, the patient is still alive and doing well.
Discussion
Mediastinal aortic pseudoaneurysms represent an uncommon complication after surgery
of the thoracic aorta or aortic valve.[1] A transsternal penetration of such aneurysms is extremely rare. To our knowledge,
such condition has only been reported sporadically in adult patients.[2]
[3] We describe such a condition in a grown-up congenital heart (GUCH) patient with
a history of HLHS.
In such cases, there is no single standard scheme of perfusion management. Due to
complex anatomical condition in GUCH patients, we recommend a combination of antegrade
and retrograde perfusion with deep hypothermia. Antegrade perfusion is used for SACP
within distal cardiovascular arrest. Deep hypothermia protects myocardium from ischemia
before the possibility of cardioplegia application. This approach is similar to safety
level 4, described by Mohammadi et al for the treatment of false aneurysm of the ascending
aorta after its prosthetic replacement.[4]
As in all complex cardiac redo surgical procedures, a careful stepwise planning is
needed beforehand to provide for all contingencies.[5]
