External carotid-to-middle cerebral bypass in the treatment of complex internal carotid injury

Management of Zone III Missile Injuries Involving the Carotid Artery and Cranial Nerves

Carotid and cranial nerve injuries from zone III (high cervical/cranial base) missile injuries are rare and difficult to treat. We have treated five patients with such injuries. We present our management scheme, and compare it to the management of the same injuries in other reports. Five consecutive zone III missile injuries presented to our institution. Trauma assessment by the trauma team, followed by detailed neurological assessment and radiographs (angiogram and computed tomography) were obtained on admission. All patients presented with dysphagia and carotid artery injury with good collateral flow, documented by angiogram. Two patients had facial nerve injury, one had trigeminal nerve injury, one patient presented with tongue weakness, and one patient suffered conductive hearing loss. No patient had evidence of stroke clinically or radiographically. Carotid artery injury was managed with bypass (3 of 5) or ligation (2 of 5). Cranial nerve injuries were documented and treated aggressively with surgery if needed. All patients were discharged to home. Patients presenting with zone III missile injuries should receive an expeditious neurological exam and four-vessel angiogram after initial trauma survey and resuscitation. Bypass of the injured portion of carotid artery is a valid treatment in the hemodynamically stable patient. The unstable patient should undergo ligation to stop hemorrhage and protect against immediate risk for stroke, with the option to bypass later. Cranial nerve injuries should be pursued and aggressively treated to minimize morbidity and prevent mortality.

Covered stent-graft treatment of traumatic internal carotid artery pseudoaneurysms: a review

OBJECTIVE

To review the literature concerning the management with placement of covered stent-grafts of traumatic pseudoaneurysms of the extracranial internal carotid artery (ICA) resulting from penetrating craniocervical injuries or skull base fractures.

METHOD

We have reviewed, from the Medline database, all the published cases in the English literature since 1990 and we have added a new case.

RESULTS

We identified 20 patients with traumatic extracranial ICA pseudoaneurysms due to penetrating craniocervical injuries or skull base fractures who had been treated with covered stent-graft implantation. Many discrepancies have been ascertained regarding the anticoagulation therapy. In 3 patients the ICA was totally occluded in the follow-up period, giving an overall occlusion rate 15%. No serious complication was reported as a result of the endovascular procedure.

CONCLUSION

Preliminary results suggest that placement of stent-grafts is a safe and effective method of treating ICA traumatic pseudoaneurysms resulting from penetrating craniocervical injuries or skull base fractures. The immediate results are satisfactory when the procedure takes place with appropriate anticoagulation therapy. The periprocedural morbidity and mortality and the early patency are also acceptable. A surveillance program with appropriate interventions to manage restenosis may improve the long-term patency.

Carotid interventions above and below the bulb

Atherosclerotic occlusive lesions of the common carotid artery (CCA), the internal carotid artery (ICA), and the intracranial branches are amenable to angioplasty and stenting. Non atheromatous occlusive lesions caused by fibromuscular dysplasia, arteritis, or trauma may also be treated by image guided intervention in selected patients. Aneurysmal lesions of the CCA, ICA and the intracranial branches of degenerative, mycotic or traumatic etiologies, as well as carotid cavernous fistulae are mostly best treated by embolization. Technological developments continuously expand the indications of interventional treatment in these vascular territories.

Radial Artery Graft for Bypass of the Maxillary to Proximal Middle Cerebral Artery: An Anatomic and Technical Study

OBJECTIVE

In this study, we aimed to investigate the use of a radial artery graft for bypass of the maxillary artery (MA) to the proximal middle cerebral artery (MCA) as an alternative to superficial temporal artery-to-MCA anastomosis or extracranial carotid-to-MCA bypass using long grafts.

METHODS

Five adult cadavers were used bilaterally. After a frontotemporal craniotomy and a zygomatic arch osteotomy, the MA was found easily 1 to 2 cm inferior to the infratemporal crest. A hole was created with a 4-mm-tip drill in the sphenoid bone 2 to 3 mm lateral to the foramen rotundum extradurally, and the dura over the hole was opened. After the carotid and sylvian cisterns had been opened, the M2 segment of the MCA was exposed. The graft was passed through the hole to reach the M2 segment. Then, the MA was freed from the surrounding tissue and was transected before the infraorbital artery branch. The radial artery graft was anastomosed end-to-end to the MA proximally and end-to-side to the M2 segment of the MCA distally.

RESULTS

The mean thickness of the MA before the infraorbital artery branch was 2.6 ± 0.3 mm. The mean thickness of the largest trunk of the MCA was 2.3 ± 0.3 mm. The average length of the graft was 36 ± 5.5 mm.

CONCLUSION

MA-to-MCA bypass is as feasible as proximal MCA revascularization using long vein grafts. The thickness of the MA provides sufficient flow; the length of the graft is short, and it has a straight course. MA-to-proximal MCA bypass may be an alternative to superficial temporal artery-to-MCA as well as extracranial carotid-to-MCA bypasses.

Proximal superficial temporal artery to proximal middle cerebral artery bypass using a radial artery graft: an anatomic approach

We present the use of radial artery graft for bypass of the proximal superficial temporal artery to the proximal middle cerebral artery. Six adult cadaver sites were used bilaterally. After apterional incision, 2x2-cm minicraniectomy was performed which began 2 cm behind the zygomatic process of the frontal bone. The superficial temporal artery was transsected before exposing the zygomatico-orbital artery branch. The proximal side of the radial artery graft was anastomosed end-to-end to the proximal superficial temporal artery and the distal side end-to-side to the proximal middle cerebral artery. The mean calibers of the proximal superficial temporal artery and largest trunk of the middle cerebral artery were 2.25+/-0.35 mm and 2.3+/-0.3 mm, respectively. The average graft length was 85+/-5.5 mm. We conclude that such bypasses are simpler than proximal middle cerebral artery revascularization using long vein grafts. This method proves that the caliber of the proximal superficial temporal artery is more suited to providing sufficient flow than the distal superficial temporal artery, and the graft is short. Such bypasses to the middle cerebral artery may be an alternative to those from the distal superficial temporal artery or extracranial carotid artery.

Blunt cerebrovascular injuries

On the basis of our experience and the available literature, we submit that aggressive screening for BCI based on injury patterns is warranted. However, several important clinical issues remain unresolved. The precise injury patterns and relative cerebrovascular risks remain to be defined. Furthermore, the optimal diagnostic screening test remains to be identified, with consideration of the relative risk-benefit profile. Finally, we must determine the best methods for the treatment of BCI. Although the definitive study has yet to be completed, the use of heparin was associated with a trend toward improved outcomes in symptomatic patients. In addition, no asymptomatic patient experienced the development of new neurologic deficits during heparin therapy. Therefore we believe that the early institution of heparin therapy is indicated. The role of endovascular stenting, however, remains unclear.

Blunt vascular injuries of the head and neck: is heparinization necessary?

BACKGROUND

Blunt vascular injuries to the head and neck (BHVI) represent some of the most devastating and morbid injuries seen by a trauma surgeon. This series reviewed the experience of a single institution to determine if diagnostic and therapeutic guidelines can be established for these uncommon injuries. In particular, the utility of anticoagulation in the treatment of these injuries is examined.

METHODS

The institutional trauma registry of a single state-designated Level I trauma center was examined for patients with BHVI. Patients were identified and their charts reviewed individually with regard to multiple data points including the type of injury, its presentation, the treatment of the injury, and the functional outcome of the patient.

RESULTS

Twenty-nine BHVI in 23 patients were reviewed from 1989 to 1997. No mortalities were noted. Among the injuries noted were 14 internal carotid artery dissections and 8 carotid artery tears. Thirteen patients had accompanying closed head injuries. Ten patients were diagnosed after an abnormal neurologic examination, and eight others were diagnosed after having carotid canal fractures. Heparin was started within 48 hours of injury in 4 patients (17%) and was used in a total of 12 patients (52%). No patient worsened neurologically after diagnosis independent of the use of heparin. Thirteen patients (57%) had no or minimal deficits upon discharge.

CONCLUSION

BHVI represent a serious cause of morbidity in the patient with multiple injuries. Patients with closed head injuries and carotid canal fractures appear most at risk. A multicenter, randomized trial involving antiplatelet therapy, full systemic anticoagulation, or observation with a long-term functional assessment is indicated to determine the optimal management of these injuries.