Keywords
aortic disease - aorta/aortic - cardiopulmonary bypass - left ventricular assist device
Introduction
Left ventricular assist devices (LVAD) therapy has become a major cornerstone in the
treatment of end-stage heart failure.[1] Simultaneous aortic valve surgery has been described. However, ascending aortic
interventions have rarely been described, which may be related to the elevated risk
of bleeding and neurological complications.[2] Considering the overall operative risk on one hand and the expected survival for
destination therapy patients on the other, individual planning for operative strategy
represents a challenge in the respective setting.
Case
A 66-year-old male patient with acutely decompensated chronic heart failure due to
ischemic and dilated cardiomyopathy was referred to our hospital with an Interagency
Registry for Mechanically Assisted Circulatory Support profile of 3, a left ventricular
ejection fraction of 24%, a cardiac index of 1.8 L/m2/min under intermittent levosimendan therapy and congestive pneumonia. The medical
history further included severe atheromatous degeneration of the aorta with suspected
aortic ulcer formation at the level of the ascending aorta ([Fig. 1]), a single vessel coronary artery disease, a thalassemia minor and protein S deficiency,
and chronic hepatitis C infection. Interdisciplinary evaluation recommended LVAD implantation
concomitant with supracoronary replacement of the ascending aorta. Considering the
atheromatous lesions reaching from the ascending aorta up to the proximal aortic arch,
and further considering the compromised overall status of the patient, a strategy
for replacement of the ascending aorta without clamping the proximal arch as well
as omitting circulatory arrest was attempted ([Supplementary Video 1]). Cardiopulmonary bypass (CPB) was installed via percutaneous venous femoral cannulation
and bilateral cannulation of the subclavian arteries. A femoral arterial access was
avoided due to the presence of vulnerable plaques in the descending and abdominal
aorta. LVAD implantation via sternotomy was performed with pericardial enlargement
in Furoshiki technique.[3] Next, under reduced perfusion the common offspring of the innominate artery and
the left carotid artery was clamped just above the aortic arch. A second clamp was
applied to the aortic arch proximal to the junction of the left subclavian artery
([Fig. 2A]). CPB perfusion via right subclavian artery was performed at 8 to 10 mL/kg bodyweight
and under pressure monitoring derived from a side branch of the perfusion cannula
targeting 60 to 70 mmHg. Cerebral oxygenation was monitored continuously. Perfusion
of the left subclavian artery was adjusted to achieve a systemic artery pressure of
70 mmHg, measured via both femoral arteries. This way, resection of the ascending
aorta with open anastomosis in the region of the proximal aortic arch was feasible
without circulatory arrest. However, surgery was done under mild hypothermia at 31.5°C.
Aortic inspection revealed soft plaques and ulceration of the lesser and greater aortic
curvature ([Fig. 2B]). Calafiore cardioplegia was given twice in the following course. Distal anastomotic
line was performed using the French cuff technique ([Fig. 2C]). Aortic clamp was relocated to the level of ascending aorta under reduced CPB perfusion
and after a meticulous de-airing maneuver. Surgery was continued in standard fashion
by performing the proximal anastomosis line at the level of the sinotubular junction
with consecutive LVAD implantation (Abbott HeartMate 3). The final anastomosis of
the LVAD outflow graft to the aortic prosthesis was performed under partial clamping
([Fig. 2D]). Total operative time was 550 minutes, including 56 minutes of reperfusion. CPB
time was 151 minutes and cross-clamping time was 49 minutes. Despite extensive intraoperative
efforts of coagulation, rethoracotomy became necessary on the same day, revealing
a diffuse bleeding tendency. The further postoperative course was prolonged due to
pneumonia-associated decarboxylation failure, necessitating venovenous extracorporeal
membrane oxygenation from 6th to 45th postoperative day. However, kidney function
was not affected. The patient remained without hemodialysis throughout the entire
stay. He recovered continuously and was transferred to the intermediate care unit
and the normal ward on 66th and 93rd postoperative day, respectively. He was finally discharged home on 115th postoperative day. At 18 months postoperatively, the patient is back to daily life
and returns to regular on-site follow-ups without neurological sequelae, not even
a wheeled walker is necessary.
Fig. 1 Preoperative computed tomography imaging: Transverse (A) and frontal (B) plane demonstrate the sizes of penetrating aortic ulcers (A: 6.8 mm, 4.6 mm) and
soft plaques (B: arrows).
Fig. 2 Surgical technique: (A) Setup for extracorporeal circulation with percutaneous venous femoral cannulation,
bilateral subclavian arterial cannulation, and clamping of the brachiocephalic trunk
and aortic arch in zone 1. (B) Situs after longitudinal incision of the ascending aorta. Soft and hard plaque formation
can be seen. (C) Distal anastomosis using the French cuff technique. (D) Implantation of left ventricular assist device (LVAD). Anastomosis of outflow-graft
under partial prosthesis clamping.
Supplementary Video 1 The video sequences illustrate the performed surgical techniques in a step-by-step
manner with additional subtitles.
Conclusion
LVAD implantation with concomitant replacement of the proximal aortic arch without
clamping of the proximal arch is a feasible surgical approach when elevated risk of
cerebral embolization or coagulopathy is expected. As patients with LVAD are already
at high risk of bleeding events,[4] the need for circulatory arrest with hypothermia can also be omitted with the shown
surgical strategy. Further risk reduction can be achieved with appropriate preparation
and precautions. Preoperative computed tomography (CT) analysis (i.e., 1-mm multislice
CT scan)[5] and intraoperative epiaortic point-of-care ultrasound have been shown as effective
in reducing embolic stroke. Bilateral subclavian cannulation and application of two
arterial clamps (one on the common offspring of the innominate artery and the left
common carotid artery and second on the distal aortic arch proximal to the left subclavian
artery) are essential factors contributing to the safety of this method. If the patient
has had no common offspring of the innominate and left common carotid artery, another
clamp would have been placed proximal to the left common carotid artery, enabling
the same approach.
This strategy may be a valid option in complex scenarios including heart failure and
advanced aortic pathology.
