Carotid Endarterectomy (Cadaver)
Table of Contents
Carotid artery stenosis is one of the leading causes of ischemic stroke worldwide. In the United States, nearly 800,000 strokes are reported each year, with ischemia accounting for 87% of them, and 15% traced to a carotid origin. An aging population and growing lifestyle factors have increased the lifetime risk of stroke over time. Carotid endarterectomy represents an effective surgical treatment for carotid artery stenosis in preventing the risk of future ischemic stroke. In this video-article, we demonstrate the surgical technique for carotid endarterectomy on a cadaver and discuss a typical case presentation of someone who may benefit from it.
Carotid artery stenosis occurs when atherosclerotic plaque builds up in the carotid artery, with risk factors similar to other atherosclerotic diseases including hypertension, hyperlipidemia, smoking, obesity, and diabetes.1-4 Carotid artery stenosis may be discovered following a transient ischemic attack (TIA), ischemic stroke, or incidentally on other imaging. Plaque is usually found in the common and internal carotid arteries within 2 cm of the carotid bulb due to complex flow patterns at that location.5 Carotid endarterectomy (CEA) refers to the surgical removal of atherosclerotic plaque from the carotid, one of the best-studied interventions for the prevention of future ischemic events in symptomatic patients with significant plaque burden.
The video demonstrates the surgical procedure on a cadaver, but in this text, we will present and discuss the medical and surgical management of a typical patient who might benefit from CEA. The typical patient to be discussed is a 64-year-old male with a past medical history of myocardial infarction status post stenting of the LAD, hypertension, hyperlipidemia, and type 2 diabetes mellitus. He presented to the emergency department with a half-hour history of painless loss of vision in the left eye. He described it as beginning at the top of his visual field and gradually involving the entire field. His vision loss resolved in the emergency department without treatment. He reported two episodes in the past week of muscle weakness in his right leg, each lasting under an hour. Imaging in the emergency department revealed a 90% stenosis of the left carotid artery and a 55% stenosis of the right. He was medically optimized and referred to vascular surgery for evaluation.
The typical patient is older, has multiple cardiovascular risk factors, and presents with focal neurologic deficits that resolve completely within 24 hours, indicative of a TIA. The episodic painless loss of vision seen in this patient is referred to as a retinal TIA, also known as amaurosis fugax. One-sided muscle weakness can be described as a hemispheric TIA. During their workup, they are found to have stenosis of the carotid artery, necessitating referral to vascular surgery.
A physical exam revealed an overweight man with no focal neurologic deficits. The pupils were equal, round, and reactive to light; acuity was intact. Visual fields were full to confrontation, and ocular movements were intact. A bruit was auscultated bilaterally over the carotid bifurcation, easier to appreciate on the left. Lower extremity pulses were diminished bilaterally.
Physical exam in a patient with carotid artery stenosis may be unremarkable. A bruit may be auscultated over the internal carotid artery; however, this is nonspecific and present in 5% of older patients in absence of significant carotid disease.4 Other signs of the arterial disease may be present, such as arterial-based claudication, nonhealing ulcers, and post-prandial abdominal pain. The presence of coronary artery disease or aneurysmal disease should also be assessed in any vascular evaluation.4
Imaging is not available for this case; however, carotid artery stenosis is typically first identified on imaging during workup for TIA using duplex ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI). Diffusion-weighted MRI within 24 hours of symptom onset is recommended by guidelines set in 2009 by the American Heart Association/American Stroke Association (AHA/ASA) for TIA/CVA work up.6 CT is considered suboptimal for the evaluation of cortical injury in this presentation; however, it is recommended if MRI cannot be performed.
Guidelines also recommend routine imaging of the cerebral vasculature as part of the evaluation of patients with suspected TIA.6 It is reasonable to begin this identification with noninvasive methods such as ultrasound, CT angiogram, and/or MRI angiogram; however, if these provide an unclear picture, cerebral angiography may be needed.6
It is important to quantify the degree of stenosis present as this will decide management. There are several comparable methods to do this. The North American Symptomatic Carotid Endarterectomy Trial (NASCET) method compares the lumen at the most stenotic portion of the vessel with the normal lumen distal to the stenosis.3 This method is used to stratify patients in mild (<50%), moderate (50–69%), and severe (70–99%) stenosis.3
Like other atherosclerotic conditions, carotid artery stenosis is progressive, with a larger atherosclerotic burden presenting higher risk and more severe symptoms. Without treatment, severe narrowing will lead to embolic stroke and decreased survival.4 Nearly one in four strokes is in patients who have had previous strokes.1
Management decisions for carotid artery stenosis depend on the degree of stenosis, health of the patient, and whether the patient is symptomatic. Medical treatment is recommended for all patients with antiplatelet, antihypertensive, and statin therapy.4 Risk factor management includes quitting smoking, exercise, and weight loss.4
Options for severe carotid artery disease include CEA and carotid artery stenting (CAS). Both provide comparable results, and the decision must be individualized to the patient.4 Regardless of endarterectomy or stenting, medical management is continued indefinitely.4
For symptomatic patients with severe stenosis, an endarterectomy is always recommended. Some guidelines recommend CEA over CAS for this patient population, especially if >70 years old.7 Symptomatic patients with moderate stenosis are also generally recommended for endarterectomy, though the benefit is considered less.7 Patients with mild stenosis or complete carotid occlusion have not been shown to benefit and are not recommended for standard internal carotid endarterectomy.7
For asymptomatic disease, there is less consensus on treatment. Guidelines generally recommend endarterectomy for asymptomatic patients with severe stenosis provided the patient is low risk for surgery and has a predicted life expectancy of at least 3–5 years.7
The patient discussed was found to be symptomatic with a 95% stenosis of the left internal carotid, necessitating the need for endarterectomy. His medications and lifestyle recommendations were reviewed and he was scheduled for CEA one week after the initial presentation with the goal of preventing future stroke.
There are some groups for whom CEA is relatively contraindicated. Those are patients with a history of radiation treatment to the head and neck due to the diffuse nature of their plaque, prior neck surgery overlying the carotid artery, and high carotid bifurcation; these patients can benefit from stenting.8 Patients with significant carotid artery stenosis are likely to have other significant risk factors for other cardiovascular diseases, which may impact the decision to have surgery.
This case presents a 64-year-old male with significant cardiovascular risk factors and intermittent neurological symptoms. Significant stenosis of the left internal carotid artery was identified, and CEA with the placement of a synthetic graft was performed.
CEA is done with an incision along the anterior border of the sternocleidomastoid muscle. After dissection to the carotid sheath, a longitudinal incision is made along the carotid artery, and the plaque is removed. The artery is reconstructed with patch angioplasty. Patching has shown lower rates of recurrent stenosis and perioperative stroke compared to primary repair;9, 10 however, primary repair can also be safe.11 Patches of synthetic material, bovine pericardium, and venous graft have shown similar short- and long-term outcomes.12
A less studied method of CEA is eversion endarterectomy. In eversion CEA, the artery is transected, and the stenosed portion is removed, creating an end-to-end anastomosis.13 It is believed that this method reduces ischemia and total operating times with similar outcomes to conventional CEA.13 Shunting can be performed during eversion endarterectomy but it is more technically demanding.
The carotid artery is clamped during surgery, risking intraoperative embolism or cerebral hypoperfusion. To mitigate this, a shunt may be placed routinely or selectively when intraoperative neuromonitoring indicates cerebral hypoperfusion. The neurological status of the patient may be monitored using several methods depending on surgeon preference and capabilities of the facility. Mixed data have not shown a benefit from shunting; however, more powerful studies are warranted.14–16 Longer cross-clamping time is a predictor for delayed neurocognitive recovery following CEA, regardless of shunting.17
Patients are monitored postoperatively for strict blood pressure control to prevent complications. Low systolic blood pressure may lead to cerebral ischemia, while high blood pressure may cause neck hematoma. A drain may be placed to avoid hematoma. Drain and surgical dressing are removed on postoperative day 1 or 2. In addition to blood pressure, patients are monitored for severe headache, stroke, and myocardial infarction. Outpatient CEA may be safe if the patient is not undergoing general anesthesia,18 but most patients will spend 1–3 days in the hospital. Patients are followed with a repeat duplex ultrasound at six weeks following surgery and then at six-month intervals.4
This case illustrates the significance of CEA in the treatment of carotid artery stenosis. Carotid atherosclerosis is insidious, with stroke symptoms the first indication of occlusive disease.5 In those presenting with symptoms, the risk of recurrent stroke is more than 18% in 30 days, highlighting the importance of treatment in preventing further morbidity and mortality.5
The first known successful attempt at surgical revascularization occurred in 1954, and enthusiasm for the procedure has steadily grown in the decades since then.2 Over time, questions arose over the efficacy and complication rates of the procedure, and which patients would benefit most.
The NASCET established that symptomatic patients with severe stenosis, defined as 70–99%, obtained the greatest benefit to CEA.2, 3 These patients saw an absolute risk reduction of 17% compared with medical management alone in the risk of ipsilateral stroke two years following surgery, with statistically significant benefit continuing at 8-year follow-up.2 Those with moderate symptomatic stenosis, 50–69%, saw a decreased but still statistically significant improvement in outcomes, while those with less than 50% stenosis saw no benefit to CEA.3
CEA is of the highest benefit when performed after 48 hours but within 14 days of symptom onset.7 There is no consensus on the appropriate interval from thrombolysis to CEA, with some studies showing an increased risk of stroke and/or death if CEA is performed within 72 hours of tPA administration.19
An increasingly accessible alternative to CEA is CAS. The Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST) compared the outcomes of patients receiving stenting with those receiving CEA.20 CREST found no significant difference in rates of periprocedural stroke, myocardial infarction, death, or subsequent ipsilateral stroke at 4-year follow-up.20 The revascularization methods came with their own periprocedural complications, with a lower incidence of periprocedural stroke in CEA and a lower incidence of MI in stenting.20 It is generally thought that younger patients may be better candidates for stenting, while older patients may derive more benefit from CEA.20 This topic is under continued study in the CREST-2 and other trials.
Recent advancements in the medical management of atherosclerosis risk factors have necessitated the need for new studies into the effects and benefits of CEA. The CREST-2 trial is currently underway, comparing modern medical management with CEA and CAS.
Other frontiers in the treatment of carotid stenosis include the use of advanced imaging and big data to identify asymptomatic and symptomatic patients who are at the greatest long-term risk of stroke and may benefit from revascularization.7
No special tools.
Nothing to disclose.
Massachusetts General Hospital has given its consent for the cadaver referred to in this video to be used for the education of healthcare professionals and is aware that information will be published online.
- Virani Salim S., Alonso Alvaro, Benjamin Emelia J., et al. Heart Disease and Stroke Statistics—2020 Update: A Report From the American Heart Association. Circulation. 2020;141(9):e139-e596. https://doi.org/10.1161/CIR.0000000000000757
Barnett HJM, Taylor DW, Eliasziw M, et al. Benefit of Carotid Endarterectomy in Patients with Symptomatic Moderate or Severe Stenosis. N Engl J Med. 1998;339(20):1415-1425.https://doi.org/10.1056/NEJM199811123392002
Beneficial Effect of Carotid Endarterectomy in Symptomatic Patients with High-Grade Carotid Stenosis. N Engl J Med. 1991;325(7):445-453.https://doi.org/10.1056/NEJM199108153250701
Grotta JC. Carotid Stenosis.https://doi.org/10.1056/NEJMcp1214999
Gokaldas R, Singh M, Lal S, Benenstein RJ, Sahni R. Carotid Stenosis: From Diagnosis to Management, Where Do We Stand? Curr Atheroscler Rep. 2015;17(2):1.https://doi.org/10.1007/s11883-014-0480-7
Easton J. Donald, Saver Jeffrey L., Albers Gregory W., et al. Definition and Evaluation of Transient Ischemic Attack. Stroke. 2009;40(6):2276-2293.https://doi.org/10.1161/STROKEAHA.108.192218
Jones Douglas W., Brott Thomas G., Schermerhorn Marc L. Trials and Frontiers in Carotid Endarterectomy and Stenting. Stroke. 2018;49(7):1776-1783.https://doi.org/10.1161/STROKEAHA.117.019496
DaCosta M, Tadi P, Surowiec SM. Carotid Endarterectomy. In: StatPearls. StatPearls Publishing; 2020. Accessed September 4, 2020. http://www.ncbi.nlm.nih.gov/books/NBK470582/
Aburahma AF, Robinson PA, Saiedy S, Kahn JH, Boland JP. Prospective randomized trial of carotid endarterectomy with primary closure and patch angioplasty with saphenous vein, jugular vein, and polytetrafluoroethylene: long-term follow-up. J Vasc Surg. 1998;27(2):222-232; discussion 233-234.https://doi.org/10.1016/s0741-5214(98)70353-2
Aburahma AF. Patch closure improves results with carotid endarterectomy. Semin Vasc Surg. 2004;17(3):243-252.https://doi.org/10.1016/s0895-7967(04)00044-4
Baram A, Majeed G, Subhi Abdel-Majeed A. Carotid endarterectomy: neither shunting nor patching technique. Asian Cardiovasc Thorac Ann. 2018;26(6):446-450.https://doi.org/10.1177/0218492318788777
Texakalidis P, Giannopoulos S, Charisis N, et al. A meta-analysis of randomized trials comparing bovine pericardium and other patch materials for carotid endarterectomy. J Vasc Surg. 2018;68(4):1241-1256.e1.https://doi.org/10.1016/j.jvs.2018.07.023
Davidovic LB, Tomic IZ. Eversion Carotid Endarterectomy : A Short Review. J Korean Neurosurg Soc. 2020;63(3):373-379.https://doi.org/10.3340/jkns.2019.0201
Rocha-Neves JM, Pereira-Macedo J, Dias-Neto MF, Andrade JP, Mansilha AA. Benefit of selective shunt use during carotid endarterectomy under regional anesthesia. Vascular. 2020;28(5):505-512.https://doi.org/10.1177/1708538120922098
Aburahma AF, Mousa AY, Stone PA. Shunting during carotid endarterectomy. J Vasc Surg. 2011;54(5):1502-1510.https://doi.org/10.1016/j.jvs.2011.06.020
Chongruksut W, Vaniyapong T, Rerkasem K. Routine or selective carotid artery shunting for carotid endarterectomy (and different methods of monitoring in selective shunting). Cochrane Database Syst Rev. 2014;(6): CD000190.https://doi.org/10.1002/14651858.CD000190.pub3
Aceto P, Lai C, De Crescenzo F, et al. Cognitive decline after carotid endarterectomy: Systematic review and meta-analysis. Eur J Anaesthesiol. Published online December 12, 2019.https://doi.org/10.1097/EJA.0000000000001130
Doberstein CE, Goldman MA, Grossberg JA, Spader HS. The safety and feasibility of outpatient carotid endarterectomy. Clin Neurol Neurosurg. 2012;114(2):108-111.https://doi.org/10.1016/j.clineuro.2011.09.011
Brinster CJ, Sternbergh WC. Safety of urgent carotid endarterectomy following thrombolysis. J Cardiovasc Surg (Torino). 2020;61(2):149-158.https://doi.org/10.23736/S0021-9509.20.11179-0
Brott TG, Hobson RW, Howard G, et al. Stenting versus Endarterectomy for Treatment of Carotid-Artery Stenosis. N Engl J Med. 2010;363(1):11-23.https://doi.org/10.1056/NEJMoa0912321
Table of Contents
Alright, so- yeah, today we're doing a left carotid endarterectomy, so typically, the way I prep and drape is essentially to expose the ear lobe, and we'll try to- we're sort of limited based on the patient's position. Rotate the head. And essentially have the midline exposed and the angle of the mandible, and then essentially the entire jaw exposed. I do typically a 5 quadrant prep with draping, but today we're doing a 4. Do you want to do this next? Yeah. Okay. So, I will mark the patient in a moment, but all the appropriate landmarks are currently exposed. Come out a little bit further. So just to delineate the anatomy, here's- sternal notch. Ear lobe is over here. and then essentially the sternocleidomastoid is here. And so our incision's essentially going to be along the anterior border of the sternocleidomastoid.
So we're just starting with the incision with the landmarks previously just described. I'll take this side. Okay. So we're starting off with the subcutaneous layer. Skin, dermis- and the first muscle layer will be the platysma. Which we can sort of start seeing now. Want to just grab a knife and just go sharply? So we're cutting through the platysma now. Okay, so here's- sternocleidomastoid, so we can try the... Exactly, so there's SCM.
Yeah, so stay right here on this sort of anterior border. Okay. I think this is the anterior border. Yeah, that is. And I'm going to grab this now, because I think that's... Sure, yeah, you could take the larger bite. Do you think this is… It's sort of splayed a little bit, but it's okay. Yeah, I kind of want to grab this. So yeah, I want to grab this and now I can sort of see the… This I'm still- want to come my way. Yeah, that's fine. So we're just mobilizing the SCM laterally. So now we're essentially trying to enter the carotid sheath. Do you want a sharp? Yeah, I mean I could do a little bit sharp, you know? Yeah. Yeah. Nice. And cut over here. Nice. Nice, yeah, that's gotta be it. I'm just trying to see where the… So now we're essentially entering the carotid sheath and identifying the carotid artery. Once we have the vagus nerve identified, we'll let you know. Is this it? It's right here. It's right there. Yeah, so there's- yeah, that's the vagus nerve, which is typically running posterior and lateral to the carotid. Okay. Looks like we can see some plaque at the bifurcation. Yeah, so it looks like here's the- exactly, here's the bifurcation. Let's open this up. Yeah, let's just take that. So as we get superior, we're looking for the posterior belly of the digastric and the hypoglossal nerve. Sharply doing everything, yeah? Yeah. Okay. Let's get a Rich. Alright good. Okay. So now we're essentially identifying the external carotid and getting control of it, followed by the internal carotid and the common carotid. Typically, we would do the common carotid first in a real patient. That's pretty much completely exposed currently. I'm looking for, right now, branches of the external carotid, which I don't see any major branches. Good. So now, let's just come- here- exactly. We could get that plane between the two. Okay. So this is the external carotid artery, which goes towards the patient's face, which has several named branches. And then… Let's take- let's actually just get a right angle and get a loop around it because then we could retract it medially. Yup. Right there. So that's one, so do a big spread- once you get in there, and just do a big spread just to open up that plane. Yeah, you can already see my instrument is… Yeah, it's already… That's pretty good. You know, it's really- at this stage just looking for... Vagus, Vagus, you know, which… Okay. Let's flip it this way. Exactly. I think you're good- yeah, you're good. I think - yeah, we're good. Okay. And then, in a typical carotid, we would do the common carotid first, followed by the external, and the internal, and do a no-touch technique to essentially not touch the area of disease and the bulb, which this patient has some disease, so that's going to be interesting when we open it. Let's see. Typically, the internal carotid has no branches- until you're intracranial. Let's see, let's just get a little bit higher on it. Alright, I'll take that Rich back. Actually, that looks more like tendon now. Yeah, that's definitely tendon. It's a little bit thick for the... A little thick. Yeah. Okay. So I don't see any branches of this- this- the external carotid, which is common. Usually you can see a- a superior thyroid branch, but that's not evident right now.
So right now, just to identify everything- let's re- let's fix that lower Weitlaner. So, here- what we identified earlier was essentially, here's the vagus nerve running posteriorly. This is the common carotid, this is external carotid, this is the internal carotid. There's some disease in the bulb of the internal carotid. And then, typically there's the- essentially the baroreceptor's nerve of- of cranial nerve IX comes right here and is typically right in this location, which may be that that goes directly to the bifurcation, ANSA is likely this structure over here, which if we trace that all the way up to- the hypoglossal. Let's open the artery up. Okay, that sounds good.
That should be good. So just come- we typically do our arteriotomy anteriolaterally. So, I'll steady the artery for you, So you just go here, just extend it up this way. Oh, wow. Pressurized- fluid. Can I use the Potts now? Yes, if you have them, if- Metz is fine, yeah. Or, a Metz. So typically we'd use Potts scissors and extend our arteriotomy- anteriolateral surface towards the internal carotid artery. And there's really minimal disease. There's some calcific disease here, but there's really no bulky, atheromatous disease in the internal carotid artery. Alright. So that's really the extent of the dissection, right here, when we do the endarterectomy, we'd find a plane and we essentially take the plaque out, leaving- really the adventitia layer, and we take- we do an eversion technique to pull the plaque out of the external carotid, and then we would sew a patch in to make artery wider. So, it's pretty straightforward anatomy. The hardest part I think of this case was the- muscles were all fused together. Yeah. So we just had to just sort of go right through it to get to it.
Good. And send that that way. Perfect. Okay. So, I would go... Should I start here? Outside-in down this, and then just go outs- you know, inside-out here, and then we'll anchor it on the ICA side. Alright. Nice. So what we're doing now is a- what they call a patch angioplasty, we're using PTFE. You typically use bovine pericardium for this part of the case after you do your endarterectomy. And we're sewing it in on the internal carotid side first. And, in real life, we actually use 3, you know, mattress sutures on this side and then secure it, and then we run the outer mattress sutures to the midpoint where these tacking sutures are. Sorry. Okay. Long tie. So then, take your SNaP off, and let's just bring this down. Okay. Okay? Okay. Do you want to- I guess we'll meet in the middle for each? Yeah. Okay. I think the easier side to do is going to be the lower side. Yeah, I think so. So do you want to do the upper side first? Yeah, let's do the upper side first. So right now we're sewing on the medial side of the patch. So right now we're doing the lateral side of the- patch, along the internal carotid artery. So now we're doing the common carotid side and completing the patch. So, typically we could use a larger needle and larger Prolene suture on this side. Given this is the common carotid, and I'm going to follow in the orientation the needle's going, which is essentially away from us. So now we're doing the lateral side of the common carotid, finishing up the patch. So at this stage I would perform flushing maneuvers, since there's only about 3 bites left. And I would then add hep saline into the lumen of the vessel. Watch your clamps. Okay, one more. Yeah.
So now we're taking all of our pseudovascular clamps off. And now we're assessing for hemostasis in the case, there would be significant bleeding throughout the suture-line, as there always is. And now, we're- ready to close.