A 52-year-old man was admitted to the head and neck surgery department for a left cervical adenopathy. No primary cancer site had been identified from endoscopic and imaging examinations. After three sessions of chemotherapy, both the scanner (figure 1) and MRI (figure 2) revealed an adenopathy that measured slightly more than 60 mm and exhibited invasion into the common and internal carotid artery. Angiographic examinations demonstrated a complete circle of Willis. We decided to carry out en bloc resection of the carotid artery and reconstruction with superficial femoral artery transplantation (figures 2, 3, 4, 5, 6 and 7). Clamping of the carotid artery lasted 25 minutes. Electroencephalogram (EEG) recordings during the operation did not elicit any cerebral pain. Post-operative care was uneventful, and the patient did not show any sign of neurological deficiency. The pathology analysis of the tumor confirmed that the carotid adventitia was invaded (figures 8 and 9). The patient benefited from cervical irradiation with a total administered dose of 70 grays. After three years of follow-up, the patient survived without any cancer recurrence, which was confirmed by 18 FDG-PET/CT (figures 10 and 11).
Interest in en bloc resection of the carotid artery
En bloc resection of the carotid artery allows for better regional control of the cancer compared to other procedures, such as radio chemotherapy or carotid artery dissection only. [1] Nevertheless, the global survival rates at 5 years are identical for carotid artery dissection and en bloc resection. [2]
Indications for en bloc resection of the carotid artery
When massive cancer invasion of the carotid artery is present (for instance, when the tumor invades the vessel over the adventitia), carotid artery dissection cannot be performed. Thus, in such cases, en bloc resection of the artery is necessary for proper surgical management of the cancer. Several imaging signs are useful for predicting a massive invasion of cancer into the carotid artery. These include deformation of the artery (which becomes oval), encasement of more than 180 degrees, and segmental obliteration of the fat between the adenopathy and the carotid artery. [3, 4]
Why do we systematically reconstruct the carotid artery?
The main risk associated with an en bloc resection of the carotid artery is cerebral stroke. If the carotid artery is removed but not reconstructed, the risk for developing a stroke is almost 30%. However, proper reconstruction of the carotid artery reduces this risk to less than 3%.[5]
Pre-operative imaging
Arteriography, angio-TDM, or MRI allows one to verify the permeability of the Circle of Willis, and therefore minimizes neurological risk when performing arterial clamping. Arteriography is the gold standard and has the advantage of allowing one to carry out a clamping test.
Technical aspects of a carotid artery resection and reconstruction via superficial femoral artery transplantation
Operative surveillance was conducted with EEG. However, similar to the use of evoked potentials, the efficiency of EEG in predicting neurological risk has not been fully demonstrated. Nevertheless, several operative assessments should be performed in order to prevent a stroke: maintenance of a stable median arterial pressure greater than 10 mmHg, achievement of a very short clamping time (less than 30 minutes if possible), and initiation of anti-coagulation (injection of 100 UI/kg of heparin) one minute before clamping. HHHeparin injection causes a more difficult tumor removal, and for this reason carotid reconstruction was performed last in our operative protocol.
Possible materials for carotid reconstruction
The superficial femoral artery was used for the transplantation. The femoral artery has the advantage of having a comparable caliber to the common carotid artery, permitting good congruence in an arterial anastomosis. As a living tissue, the femoral artery is also resistant to infection following postoperative radiotherapy. In contrast, the absence of stenosis at the arterial level should be controlled by at least a Doppler echo. Moreover, transplantation of the femoral artery necessitates reconstruction of the section removed, which was replaced with Dacron prosthesis.
Certain authors use Dacron or ePTFE (expanded polytetrafluoretylene) prosthetics to carry out the carotid anastomosis. [5]
