Discussion
Although FET combines the advantage of open and endovascular surgery, it is still major surgery with prolonged ischemia time. The perioperative complication is similar to the classical total arch replacement, with paraplegia proving to be the chink in armour for FET. Several steps taken to reduce the complication include short stent graft, reimplantation of the LSA artery, and reduction of the circulatory arrest.
Reimplantation of the LSA in FET may be challenging in (i) Obese individuals (ii) Patients with a deep chest (iii) Elongated aorta (iv)Large aortic arch aneurysm (v) Re-operative procedures. Several surgeons have tried different techniques to reimplant the LSA including the LCCA-LSA artery bypass, extra anatomic aortic-axillary bypass [1] and, clamping the descending thoracic aorta and compressing the aortic arch to facilitate the exposure and anastomosis of LSA [2]. An additional incision for extra-anatomic aortic-axillary bypass through the left thorax may be cumbersome besides the risk of injury to brachial plexus (1.5%) during exposure of left axillary artery [3]. LSA is often an elastic, thin fragile artery and when involved in aortic dissection, it is even worse. Performing anastomosis on this artery in the deep intrathoracic compartment is technically difficult making future haemostasis further a challenge.
Some centers that perfuse the LSA during the cardiopulmonary bypass, a tube graft can be anastomosed to the artery in an end to end fashion, which can later be connected to the hybrid prosthesis. The advent of Neo-Evita Spielvogel in the market will empower the surgeon for a “no-arch-touch” Zone 0 implantation [1]. The above exposure will facilitate the LSA reimplantation during the same.
The incidence of direct aortic origin of left vertebral artery (LVA) from the aortic arch varies from 2.4 - 5.8% in different studies and in 50% of individuals the LVA is dominant [4,5]. The LVA has to be reimplanted directly or using an autologous vein, either to the LCCA or the LSA to protect the posterior cerebral circulation and the spinal cord [5,6]. Given the delicate nature of the LVA, meticulous handling without stretching is essential to avoid intimal damage. We believe, our technique will provide adequate exposure of the LVA for a meticulous anastomosis to the LSA or LCCA.
Our technique provides excellent exposure of LSA for an effective anatomical reconstruction in the mediastinum. The division of the sternocleidomastoid coupled with the sandbag behind the left shoulder brings the LSA superficial enabling anastomosis without any difficulty. Additional manoeuvres described above will further aid in the exposure and rerouting. The division of the sternal head of sternocleidomastoid will not cause any functional disability [7]. We agree that the scar of the wound is a bit long and extends to the neck. In our experience, there were no problems in wound healing.