Selective internal carotid artery cross-clamping increases the specificity of cerebral oximetry for indication of shunting during carotid endarterectomy

BACKGROUND

An indication for selective shunting during carotid endarterectomy (CEA) is based on monitoring during a procedure. Cerebral oximetry (CO) using near-infrared spectroscopy (NIRS) may be a simple technique, but its relevance during CEA, especially with respect to cutoff values indicating shunt implantation, still needs to be elucidated.

METHODS

One hundred twenty five patients underwent CEA under local anesthesia (LA) and were monitored clinically throughout the whole procedure. The patients were also monitored using bilateral NIRS probes during surgery. The NIRS values were recorded and evaluated before and after selective cross-clamping, firstly by the external carotid artery (ECA), followed by the internal carotid artery (ICA). The decrease in the ipsilateral CO values, with respect to the indication of shunting, was only analyzed after selective cross-clamping of the ICA. The decision to use an intraluminal shunt was solely based on the neurological status evaluation after ICA cross-clamping.

RESULTS

One hundred five patients (85%) were stable throughout the CEA, while 20 patients (15%) clinically deteriorated during surgery. The mean drop in the CO after selective ICA clamping in clinically stable patients was 6%, while in patients with clinical deterioration, the NIRS decreased by 14.5% (p < 0.05). When the cutoff value for selective shunting was set as a 10% decrease of the ipsilateral CO after selective ICA clamping, the sensitivity of the technique was 100% and the specificity 83.0%.

CONCLUSIONS

Our study showed that a 10% decrease in the ipsilateral brain tissue oximetry after selective cross-clamping the ICA provides a reliable cutoff value for selective shunting during CEA. Despite the availability of a variety of monitoring tools, the NIRS may be an easy, reliable option, especially in the scenario of acute CEA in general anesthesia.

Effective Intraluminal Shunt in Carotid Endarterectomy for Carotid Artery Near Occlusion: Technical Report

BACKGROUND

Carotid artery near occlusion is a critical degree of stenosis whereby blood flow is decreased and the distal cervical and intracranial internal carotid arteries (ICAs) are prone to collapse. Considering the diminished perfusion and risk of progression to total occlusion and periocclusive embolism, we performed carotid endarterectomy for carotid artery near occlusion.

METHODS

Accurate evaluation of tandem stenosis or patency of the poststenotic ICA in carotid artery near occlusion is often difficult preoperatively. Thus we performed carotid endarterectomy in a hybrid operating room where intraoperative digital subtraction angiography (DSA) and endovascular angioplasty or stenting for distal lesions can be performed if necessary. In addition, to evaluate the distal ICA intraoperatively, we used an intraluminal shunt for shunt angiography, with injection of contrast material through the shunt tube, as a replacement for conventional DSA. Furthermore, an intraluminal shunt held the collapsed lumen open and provided a scaffold for suturing, which prevented postoperative stenosis of the distal ICA.

CONCLUSION

The present report is intended to underline the merits of intraluminal shunt as a replacement for conventional DSA and as a scaffold for suturing.

Triple-balloon shunt placement for carotid endarterectomy: a novel intraluminal shunt designed to preserve the internal and external carotid blood flow

OBJECTIVE

To report a newly developed intraluminal triple-balloon shunt designed to preserve the blood flow of both the internal carotid artery (ICA) and the external carotid artery (ECA) during carotid endarterectomy in patients with a previous ipsilateral extracranial-intracranial bypass, in whom hemodynamic cerebral ischemia might be caused by cross-clamping at the ICA as well as the ECA.

METHODS

The novel device consists of 3 silicone tubes equipped with balloons at each end. The design facilitates insertion proximally to the common carotid artery and distally to both the ICA and the ECA.

RESULTS

The new shunt tube was used in 3 patients, each of whom had previously undergone ipsilateral superficial temporal artery-middle cerebral artery bypass for proximal middle cerebral artery occlusion. The blood flow of the middle cerebral artery and anterior cerebral artery was supplied independently from the ECA via the bypass and from the ICA, respectively. There were no shunt-related complications.

CONCLUSIONS

This novel shunt device can be used safely and effectively in cases requiring preservation of the blood supply to both the ICA and the ECA during carotid endarterectomy.

Temporary vascular shunts

Temporary vascular shunts have been used for nearly 100 years in patients. Originally, they were used as vascular grafts that were likely to thrombose as collaterals would hopefully develop. More recently, they have been used as a device to be replaced by a permanent vascular graft during the same operation or at a reoperation. Indications for the use of shunts are a "damage control" procedure for a peripheral or truncal vascular injury, Gustilo IIIC fracture of an extremity, need for perfusion as a complex revascularization is performed, and planned replantation of a hand, forearm, or arm. They are used in approximately 8% of vascular injuries treated in urban trauma centers in the United States and have an excellent patency rate without heparinization.