Carotid Artery Reconstruction with an Autologous Bifurcated Saphenous Vein Graft

We present a new technique for carotid artery reconstruction using a modified bifurcated saphenous vein graft in a patient with a malignant neck tumor. This technique can optimize the size match between the SVG and common carotid artery, as well as the internal and external carotid arteries. Post operative computed tomography performed a year after the operation demonstrated excellent graft alignment and patent carotid arteries.


Introduction
We herein report our technique for internal and external carotid artery reconstruction using a modified bifurcated saphenous vein graft (SVG) in a patient with a malignant neck tumor.Informed consent for patient information and images to be published was obtained from the patient.

New Methods
A 58-year-old man presented to the outpatient department of otorhinolaryngology with a left-sided cervical mass increased in size.His medical history was unremarkable, except for hypertension.A needle biopsy of the mass revealed that it was a metastatic tumor of the cervical lymph node originating from a thyroidal to prevent thrombus formation at the suture line.The created trunk of the bifurcated SVG was 5 mm in length (Fig. 2B).CCA, ICA, and ECA were cross-clamped and resected with sufficient margins from the edge of the tumor.The tissue oxygenation index (TOI) of both sides of the brain was continuously monitored during the procedure using NIRO 200NX (Hamamatsu Photonics, Hamamatsu, Japan).Generally, if TOI shows a >20% decline from the baseline value, we routinely use distal perfusion devices such as shunt tubes.
Vein grafting was performed consistently in a reverse fashion.The reversed SVG did not undergo a valvulotomy.The trunk of the bifurcated graft, measuring 8 mm in diameter, was anastomosed to the common carotid artery using continuous 5-0 polypropylene sutures in an endto-end fashion.One of the distal ends of the bifurcated graft was anastomosed to the ICA by using continuous 6-0 polypropylene sutures in an end-to-end fashion.The internal carotid artery (ICA) cross-clamp time was 20 min.ECA reconstruction was performed in the same manner as the ICA reconstruction (Fig. 2C).TOI showed no significant decline during the cross-clamp, and no distal perfusion devices were required.
Mechanical ventilation was discontinued on postoperative day (POD) 1 without any neurological complications.Low-dose aspirin was administered on POD 1, which was

Discussion
One major issue related to carotid artery reconstruction is the graft material to be used.][3] We originally utilized the bifurcated SVG as a vascular graft for reconstruction of the femoral arterial bifurcation, especially in patients with either a synthetic graft infection or an infective pseudoaneurysm of the femoral arteries.This is the first case in which the technique was applied to carotid artery reconstruction.Illuminati et al. reported the excellent long-term patency of ePTFE. 4,5)owever, while ePTFE grafts offer better resistance to tissue scarring and radiation therapy than autologous tissue grafts, they have the inherent disadvantage of vulnerability to infection.One of the major advantages of our new method is that we can double the diameter of the proximal end of the SVG and adjust the mismatch between the diameters of the SVG and CCA.At the same time, the distal ends of the bifurcated SVG remained at the normal diameter, which matched the diameter of the ICA and ECA.Size mismatch between the SVG and the native carotid arteries can act as a major factor influencing SVG graft stenosis or occlusion.Flow turbulence causes shear stress at the size-mismatched anastomosis site, which can produce intimal abrasion and lead to intimal inflammatory changes.Some authors have reported that the use of large-caliber autologous grafts, such as deep or superficial femoral veins, for carotid reconstruction can prevent graft thrombosis or occlusion. 2,6)ur bifurcated SVG can provide twice the diameter at the proximal end of the SVG without any complicated techniques and allows for better size matching with the CCA in this case.However, in our method, the suture line used to create the bifurcation crossed the proximal anastomosis line.This may increase the risk of thrombus formation at the proximal anastomosis site.Low-dose aspirin was administered for 6 months postoperatively to avoid thrombus adhesion at the suture line.Special attention should be paid to prevent placing suture knots inside the vascular lumen.
The benefits of ECA preservation remain unclear. 1,7)lthough most surgeons agree to sacrifice the ECA, we recommend reconstructing the ECA whenever possible.The ECA can provide important collateral flow to both the brain and eye in the face of ipsilateral ICA occlusion.In addition, if the ECA is sacrificed, emboli may originate from the external carotid stump, which can cause ophthalmologic or neurological symptoms. 8)An additional advantage of ECA reconstruction is the possibility of using this vessel as the arterial supply for free tissue transfer, especially in patients with malignant tumors who will experience extensive tissue loss if they develop recurrent disease. 1)ur bifurcated SVG technique is a simple but effective option for ICA and ECA reconstruction in patients with advanced neck cancer.This technique can optimize the size match between the SVG and CCA, as well as between the SVG and ICA or ECA.