Cervical and Thoracic Vascular Injuries

Neck

All neck injuries require a neck and chest xray to look for fractures, missiles, associated hemopneumothorax, widened mediastinum, and subcutaneous emphysema.  If patient is unstable, he or she is directly taken to the operating room. If the patient has stable vital signs, CTA of the neck and chest is the best initial screening tool for penetrating injuries.

Neck is divided into three zones (figure 1). Zone 1 is the base of the neck below the cricoid cartilage. Zone 2 extends from the cricoid cartilage to the angle of the mandible and zone 3 extends to the base of the skull.

For trauma to Zone 1, the approach is an incision at the SCM border and occasionally extending it down inferiorly, because sometimes you may need to perform median sternotomy in order to gain access to proximal intra-thoracic vessels. The innominate vein can be retracted or ligated in order to gain access to the aortic arch and dissection along the arch can expose the origin of the innominate and left common carotid and perhaps portion of the proximal left subclavian artery.

Due to the posterior location of the left subclavian artery and difficulty exposing the entire vessel, a high anterolateral incision may be required.

Zone 2 exposure is best approached using an incision along the sternocleidomastoid muscle. When bilateral structures of the neck are potentially injured, a collar incision may be preferable. The facial vein is divided to obtain better exposure of the carotid artery bifurcation, which is located deep to the vein.  Most external carotid injuries may be ligated without consequence. Ligation of the common or internal carotid artery should be avoided because ot can result in devastating nerurologic sequelae. The great saphenous vein is a good size match with the internal carotid artery and can be used as an interposition graft. The external carotid artery can be used as a interposition graft for injuries to the internal carotid artery.

For trauma to zone 3, due to retro mandibular location of distal carotid artery, sublaxation of the mandible or osteotomy maybe required.  The digastric muscle and styloid process can be divided as well. CN VII, IX and XII are at risk.

Operative exposure of the vertebral artery may be difficult. The vertebral artery is anatomically divided into 4 zones. V1 extends from the take off the subclavian artery to the interosseous process of C6, V2 extends from C6 to C2, V3 from C2 to the skull base and V4 from base to the confluence of the right and left vertebral arteries which form the basilar artery.

Chest

Most patients with either blunt or penetrating injuries to the aorta die at the scene. Injury to the descending aorta usually occurs just distal to the left subclavian artery. 

If a patient with blunt aortic injury makes it to the trauma unit, the patient should first be resuscitated and undergo an anterolateral thoracotomy through the left 4^th intercostal space.  This will provide rapid access to the pericardium, pulmonary hilum, and the aorta. If further exposure is need a clamshell is performed by transecting the sternum and extending the incision to the right side. If Clamshell is performed both internal mammary arteries should be ligated to prevent delayed bleeding.  Clamping of the thoracic aorta will improve circulation to the brain and the heart. The most feared complication of this technique is paraplegia, however, ischemic bowel and renal failure may also result from prolonged clamping.

There is recent evidence that not all blunt aortic injuries need repair. Blunt aortic injury is classified based on the absence (intimal tears and large intimal flaps) or presence (pseudoaneurysm and ruptures) of external contour abnormalities of the aorta.  Intimal tears are managed non-operatively. Large intimal flaps can be treated with stent grafting.  If a pseudoaneurysm is going to rupture, it’ll do so early and if not they can be treated with endovascular repair within 1 week and these patient should be monitored with serial CT imaging.

Median sternotomy provides access to the aortic arch.

Exposure of right supraclavicular artery distal to the right vertebral artery is through a right supraclavicular incision (Figue 2, A) starting at the sternoclavicular junction over the clavicle. If injury is proximal to the right vertebral artery then median sternotomy is needed (Figure 2, B).

  

Exposure if the left subclavian artery can be done by three incisions:

Left supraclavicular incision

Left anterolateral thoracotomy

Left sternoclavicular flap (trap flap)

Injuries to Lt subclavian artery proximal to the vertebral artery can be repair by the left supraclavicular incision. Once incision is made the scalene fat pad is identified and incised and scalene muscle is divided to expose the left subclavian artery.

Injuries distal to the vertebral artery are best approached using a high left anterolateral thoracotomy through the 3^rd intercostal. 

If the left anterolateral thoracotomy is not adequate then a mid sternotomy is performed which this makes it a trap flap incision.

In patients in extremis, the subclavian artery can be ligated (as part of damage control surgery), preferably proximal to the vertebral artery so that the retrograde flow through the vertebral and it collaterals goes to the extremities. If sudden ischemia occurs, then start heparinization followed by revascularization.

from Dr. Reza Salabat