Townsend Courtney M.Jr., Evers B. Mark. Atlas of General Surgical Techniques: Expert Consult

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CHAPTER 84 • Carotid Endarterectomy 911

Sternocleidomastoid

FIGURE 84 –3

Common carotid

artery

External carotid

artery

Occipital artery

Hypoglossal nerve

Ligated anterior

facial vein

Internal carotid

artery

Internal

jugular

vein

Vagus

nerve

FIGURE 84 –4

912 Section XII • Vascular

◆ Other methods for shunt determination include electroencephalogram, somatosensory

evoked potentials, or awake patient monitoring. The electroencephalogram measures global

hemispheric functioning, and evoked potentials measure peripheral nerve function. In gen-

eral, a ﬂ attening of amplitude on the affected side indicates the need for a shunt. If the

patient is awake and a shunt is required, the patient will lose function of the contralateral

hand or foot, or both, and be unable to follow commands. It should be emphasized that

these changes are almost immediate, so this assessment requires at most 3 minutes.

◆ Once the decision regarding shunting has been made, an arteriotomy is created on the distal

anterior surface of the common carotid artery using a no. 11 blade and is extended through

the region of plaque in the internal carotid artery using Potts scissors (Figure 84-5).

◆ If a shunt is to be used, it should be ﬂ ushed with heparinized saline and clamped in the mid-

portion before insertion (Figure 84-6, A). I insert the proximal end into the common carotid

ﬁ rst, ﬂ ush blood out the distal end, reclamp the mid-portion, insert the distal end into the

internal carotid artery, check for bubbles, and then release the clamp (Figure 84-6, B-C).

Either specially designed shunt clamps or Rumel tourniquets can be used to ﬁ x the shunt in

the arterial ends during endarterectomy. During the shunt insertion, the common and internal

carotid arteries should be controlled with doubly looped vessel loops.

Hypoglossal nerve

External

carotid

artery

Superior thyroid

artery with Pott’s ligature

Ansa cervicalis

nerve

Internal jugular vein

Proposed

arteriotomy

Vagus nerve

FIGURE 84 –5

CHAPTER 84 • Carotid Endarterectomy 913

Shunt

Clamp

Common carotid

artery

Internal carotid

artery

Shunt

Plaque

Shunt

FIGURE 84 –6

914 Section XII • Vascular

4. ENDARTERECTOMY

◆ The endarterectomy is performed using a Freer elevator (Figure 84-7). This is inserted into

the plane between the circular muscle ﬁ bers and the adventitia, beginning in the common

carotid artery. The adventitia is pushed away from the muscle ﬁ bers extending distally.

When the end of the plaque is reached, gentle pressure on the plaque pulling inferiorly and

toward the contralateral side will usually separate it from the normal distal artery. Alterna-

tively, a Beaver blade can be used to divide the plaque from the normal artery. The plaque

can then be peeled off transversely. The remainder of the plaque is removed from the inter-

nal and common carotid arteries in a similar fashion.

◆ The plaque is removed from the external carotid artery using an eversion technique. The

adventitia of the artery is everted by the surgical assistant, while the plaque and circular

muscle ﬁ bers are dissected away circumferentially by the surgeon using the Freer elevator.

The plaque is avulsed at its natural end.

◆ Once the specimen is removed, any remaining debris or circular smooth muscle ﬁ bers can

be removed by scraping transversely with the Freer elevator or a Kittner sponge. If the edge

of the distal endpoint has been lifted up, it should be tacked down with 7-0 Prolene as

shown in Figure 84-8. The proximal endpoint does not need to be tacked because it will

be pushed into the adventitia of the artery by the blood ﬂ ow.

CHAPTER 84 • Carotid Endarterectomy 915

Freer

elevator

Plaque

FIGURE 84 –7

Circular

muscle fibers

Tacking

suture

Proximal

intima

Endarterectomized

artery

Distal intima

Endarterectomized

section

FIGURE 84 –8

916 Section XII • Vascular

◆ It is the current standard of care to close the arteriotomy with a patch, as shown in

Figure 84-9. Prosthetic patches are used most commonly, either Dacron or expanded

polytetraﬂ uoroethylene (ePTFE). Before the ﬁ nal closure, ﬂ ushing should be performed

with care taken to ensure that the internal carotid artery is ﬂ ushed last. If a shunt has been

used, this should be removed before ﬂ ushing. Once ﬂ ushing is completed, the inner surface

of the endarterectomized vessel is irrigated copiously with heparinized saline, and the clo-

sure is completed. The internal carotid artery is then back-bled into the common carotid ar-

tery and gently clamped across its origin. (I use DeBakey pickups.) Flow is then restored

through the common carotid artery into the external carotid artery, providing an additional

means for ﬂ ushing any remaining debris or air, or both, into the external carotid artery

rather than the intracranial circulation. After 10 seconds, ﬂ ow is restored through the inter-

nal carotid artery.

◆ It is possible to perform an intraoperative duplex ultrasound or angiogram to check the

operative result, although this has not been my practice.

FIGURE 84 –9

CHAPTER 84 • Carotid Endarterectomy 917

5. CLOSING

◆ The heparin can be reversed using protamine, if necessary. The platysma is closed with

running 3-0 Vicryl. The skin is closed with 4-0 Monocryl and surgical glue. In some cases,

I place a drain in the surgical site, bringing it out through a lateral skin stab incision. If a

drain is used, it should be removed on the morning of the ﬁ rst postoperative day.

STEP 4: POSTOPERATIVE CARE

◆ Aspirin or clopidogrel, or both, should be continued daily throughout the postoperative

period. Most surgeons would continue at least one of these medications for life.

◆ Drains should be removed on the ﬁ rst postoperative day.

◆ Hematoma in the neck can cause respiratory compromise. If a rapidly expanding hematoma

or any evidence of respiratory compromise exists, the patient should be return emergently

to the operating room for evacuation and control of the hemorrhage.

◆ Cranial nerves, which can be injured during the surgery, include the vagus, recurrent laryn-

geal, external branch of the superior laryngeal, hypoglossal, and marginal mandibular branch

of the facial. Vagal and recurrent laryngeal injuries result in hoarseness secondary to vocal

cord paresis or paralysis in the midline. A patient who is hoarse after carotid surgery should

have a vocal cord assessment, in particular if contralateral carotid surgery is contemplated.

Bilateral vocal cord paralysis requires emergent intubation or tracheostomy, or both. Injury

to the external branch of the superior laryngeal nerve results in loss of the resonance and

high tones in the voice. Hypoglossal nerve injury results in deviation of the tongue to the

side of the injury; this can result in reduced ability to move food around in the mouth and

drooling. Injury to the marginal mandibular nerve results in pulling of the inferior aspect of

the mouth in a direction away from the injury. In general, hypoglossal and marginal mandib-

ular nerve injuries are temporary.

◆ Patients, particularly those who undergo carotid endarterectomy under general anesthesia,

can experience blood pressure instability after surgery. Most commonly, this is manifested as

hypertension, which can be treated with intravenous medication such as nitroprusside.

Hypotension, which is less common, can be treated with medication such as phenylephrine.

◆ The most feared complication after carotid endarterectomy is stroke, which can occur intra-

operatively or postoperatively. Intraoperative strokes are usually treated with anticoagulant

or antiplatelet therapy postoperatively. Postoperative strokes (in other words, the patient’s

neurologic examination is normal immediately after surgery, but changes within the ﬁ rst

12 to 24 hours) should be treated by emergent return to the operating room because of the

possibility of carotid thrombosis. This can be treated with thrombectomy and possibly

thrombolytic therapy.

918 Section XII • Vascular

STEP 5: PEARLS AND PITFALLS

◆ Injury to the marginal mandibular nerve can be avoided by not retracting the mandible too

strongly.

◆ Division of an unusually large ansa cervicalis crossing anterior to the carotid bifurcation will

usually result in hoarseness. Avoid cutting it if possible.

◆ Because of the risk of infection and carotid rupture, a tracheostomy adjacent to a fresh ca-

rotid endarterectomy is a disaster and should be avoided at all costs.

SELECTED REFERENCES

1. North American Symptomatic Carotid Endarterectomy Trial Collaborators: Beneﬁ t of carotid endarterec-

tomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med 1991;325:445-453.

2. North American Symptomatic Carotid Endarterectomy Trial Collaborators: Beneﬁ t of carotid endarterec-

tomy in patients with symptomatic moderate or severe stenosis. N Engl J Med 1998;339:1415-1425.

3. Executive committee for Asymptomatic Carotid Atherosclerosis Study: Endarterectomy for asymptomatic

carotid artery stenosis. JAMA 1995;273:1421-1428.

4. Ricotta JJ Jr, Malgor RD: A review of the trials comparing endarterectomy and carotid angioplasty and

stenting. Perspect Vasc Surg Endovasc Ther 2008;20:299-308.

919

STEP 1: SURGICAL ANATOMY

◆ A comprehensive understanding of the anatomy of the leg is essential to performing the

procedure and avoiding future complications. This anatomy includes the femoral triangle

and the popliteal space below the knee. The saphenous vein can have many variations in

its course in the thigh. Identifying the main branch and avoiding a ﬂ ap are key points

(Figures 85-1 through 85-3).

CHAPTER

Femoropopliteal Bypass

(In Situ)

Lori Cindrick Pounds

Medial accessory

saphenous vein

Superficial external

pudendal vein

Great

saphenous vein

Sartorius muscle

Femoral vein

Inguinal ligament

Femoral nerve

Femoral triangle

Profunda artery

Femoral artery

Superficial

femoral artery

Anterior lateral accessory

saphenous vein

FIGURE 85 –1

920 Section XII • Vascular

Medial superior

geniculate artery

Popliteal vein

Hunter’s canal

Adductor

magnus muscle

Posterior View

Sural artery

Medial inferior

geniculate artery

Popliteal

muscle

Lateral inferior

geniculate artery

Soleus muscle

Popliteal artery

Lateral superior

geniculate artery

Sural artery

Popliteal vein

Popliteal artery

Soleus muscle

Medial head

gastrocnemius muscle

Semitendinosus muscle

Gracilis muscle

Sartorius muscle

Round

pillow bump

FIGURE 85 –2