Effectiveness of simultaneous longitudinal incision of the external carotid artery in standardized carotid endarterectomy

doi:10.21203/rs.3.rs-4692098/v1

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Effectiveness of simultaneous longitudinal incision of the external carotid artery in standardized carotid endarterectomy

https://doi.org/10.21203/rs.3.rs-4692098/v1

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Objective: To evaluate the safety and effectiveness of longitudinal incision of external carotid artery(ECA) during standardized carotid endarterectomy(CEA).

Materials and methods:A retrospective study was conducted on 30 patients with simultaneous internal and external carotid artery stenosis who were evaluated by carotid ultrasound and Transcranial Doppler(TCD) and neck CT angiography(CTA) or DSA in Liaocheng Second People's Hospital from January 2020 to January 2022. All patients underwent internal and external carotid endarterectomy under intraoperative TCD monitoring. Carotid ultrasound and TCD reexaminations were performed 3 months, 12 months, and 18 months post operation. Restenosis of the carotid artery and cerebral blood perfusion were evaluated.

Results: There were 22 men and 8 women in 30 cases,including 2 cases with mild stenosis of the ECA, 15 cases with moderate stenosis, and 13 cases with severe stenosis. All patients underwent surgeries smoothly and no perioperative complications occurred. There were no cases with stenosis in 3 months, 3 cases present stenosis in 12 months, and 3 cases present stenosis in 18 months post operation. Cerebral ischemia stroke occurred 18 months after surgery in 1 case. Cerebral blood perfusion improved in all patients after surgery. The restenosis rate of the carotid arteries was 16.7% and the ischemic stroke rate was 3.3% after 18 months’ follow-up.

Conclusion: Simultaneous longitudinal incision of the ECA in standardized carotid endarterectomy is a safe and effective surgical method. It not only restores the normal anatomical structure of the external carotid artery, but also effectively hinder carotid artery restenosis and occlusion rate, improves cerebral blood perfusion especially in patients with poor compensation of intracranial collateral circulation, and thus reduces the occurrence of ischemic stroke events.

external carotid artery

internal carotid artery

endarterectomy

restenosis

cerebral blood perfusion

CEA is an effective method for the treatment of Carotid artery stenosis. When the internal carotid artery is occluded or narrowed, the role of the ECA as a collateral circulation supplying blood to the brain has been well documented. [1, 2] For patients with ECA stenosis, the ECA would not be incised usually and the distal plaque would not be removed completely. Some people think that CEA without sufficient endarterectomy of ECA is easy to lead to restenosis of carotid artery or related neurologic complications, this view has been controversial.༻3༽Therefore, our center conducted a retrospective study of patients who underwent a standardized endarterectomy with simultaneous internal and ECA longitudinal double incision. These patients were followed up preoperatively and postoperatively by carotid ultrasound + TCD, to monitor the occurrence of carotid restenosis and ischemic stroke, and to indirectly indicate the related causes of restenosis through the characteristics of ultrasonography.

A retrospective analysis of 30 Carotid artery stenosis patients in the second people's Hospital of Liaocheng from January 2020 to January 2022 was carried out, all patients underwent preoperative and postoperative cervical vascular ultrasound plus TCD by the same ultrasound specialist.Dopler's PSV criteria for ultrasound scanning: The blood flow velocities of internal and external carotid arteries were assessed as follows:①flow velocity < 125cm/s is < 50%,mild stenosis;②flow velocity 125cm/s-230cm/s is 50%-70%,moderate stenosis;③flow velocity ≥ 230cm/s is 70%-99%,severe stenosis.We defined restenosis with PSV ≥ 50% during ultrasound examination of internal and external carotid arteries during postoperative follow-up. [1]

In this study, 30 patients with moderate and severe stenosis of internal and external carotid arteries were examined by carotid ultrasound, TCD and CTA before operation accordding to the CEA surgical adaptability, Inclusion criteria for incision of ECA: ①The length of ECA plaque was more than 1cm。②When the ECA was not incised, the distal intimal margin could not be well handled under the microscope.exclusion of surgery related contraindications.The most common risk factor was smoking (66%). Other risk factors included diabetes (24%), hypertension (63%) and coronary artery disease (64%) .Intraoperative shunt protection was evaluated by TCD monitoring.There were 10 cases of moderate stenosis and 20 cases of severe stenosis of internal carotid artery(ICA). There were mild stenosis in 2 cases, moderate stenosis in 15 cases and severe stenosis in 13 cases of ECA.

The standard CEA technique is to incise the ICA and the common carotid artery(CCA) under the microscope, to separate the internal and common carotid plaque completely with the exfoliator, and to treat the residual plaque at both ends carefully with the fiber coil forceps, to avoid the formation of an endomembranous valve following the flow of blood.Preoperative imaging evaluation and TCD monitoring were performed, we usually fall into two categories: ①For patients with bypass tube protection during the operation of poor collateral circulation compensation, the internal cervical plaque can be removed first and then the external cervical plaque can be treated.For the management of the ECA our strategy is to first transected the plaque at the origin of the ECA and then longitudinally incise the ECA at 5 mm distal to the bifurcation, carefully handling the distal residual plaque; Complete dissection of the entire ECA plaque.The intraoperative surgical process is shown in Fig. 1.

②For good collateral circulation, without using bypass tube protection during the operation, Firstly rapid removal of cervical and common cervical plaque, then we typically suture the ICA and CCA to restore blood flow in the ICA. so as not to increase cerebral ischemia due to prolonged occlusion time.Then the ECA proximal and distal application of blocking clamp, we proceed to handle the CEA calmly as described above。Finally, the ECA adventitia is sequentially sutured in a watertight manner.Surgical illustration as Fig. 2.

After the completion of suturing, immediate intraoperative ultrasound monitoring is performed to assess the status of plaque excision, the flow velocity of the internal and external carotid arteries, the integrity of the incision margins, and the presence of any intraluminal valves.A follow-up CTA examination of the neck blood vessels is recommended within 3 days after surgery to visually assess the recovery of stenosis. All patients are advised to receive reasonable control of blood pressure, blood sugar, oral aspirin tablets for antiplatelet therapy, atorvastatin calciun tablet, and counseling on smoking cessation and alcohol abstinence during hospitalization or after discharge. Additionally, neck vascular ultrasound + TCD monitoring follow-ups are scheduled at 3 months, 12 months, and 18 months postoperatively. The data analysis will be presented in percentages.

Preoperative ultrasonography and CTA/DSA examination showed moderate stenosis of ICA in 10 cases and severe stenosis in 20 cases. ECA stenosis occurred in 2 patients with mild stenosis, 15 with moderate stenosis, and 13 with severe stenosis. Among them, 12 cases had symptomatic stenosis, 18 cases had non-symptomatic stenosis, 13 cases had used intraoperative bypass tube protection and 17 cases had unused. No vessels occlusion was found in preoperative and postoperative follow-up, and no death occurred during the period. There were 3 cases of restenosis 12 months after surgery, including 1 case of ICA and 2 cases of ECA moderate stenosis. At 18 months after operation, 5 cases of restenosis occurred, of which 2 case ECA and 1 ICA had moderate stenosis, 1 case had severe ECA stenosis.One patient developed severe ICA restenosis complicated with mild limb weakness. Cervical vascular ultrasound and TCD monitoring were performed before surgery and 3, 12 and 18 months after surgery for follow-up of internal and external carotid artery stenosis, as shown in Table 1.

Table1：ICA,internal carotid artery，ECA, external carotid artery

All the 8 patients with recurrent restenosis did not take regular oral administration of antiplate and lipids after surgery, and the control of blood sugar and lipids was unsatisfactory, and 2 patients with severe stenosis still did not quit smoking and alcohol. The rate of restenosis after carotid artery dissection was 16.7% and the rate of ischemic stroke was 3.3%. The restenosis rate after ICAvsICA + ECA endarterectomy is shown in Table 2. We found that internal and external carotid artery restenosis by ultrasound showed carotid intimal thickening with local uneven echo, and it was considered that the intimal inflammation was the main cause of recurrence.

Table 2:The restenosis rate after ICAvsICA+ECA endometriectomy

Postoperative restenosis case example: The patient is an elderly male who underwent carotid artery ultrasound preoperative evaluation due to right carotid artery stenosis, as shown in Fig. 3A-C,After excluding surgical contraindications, perform right ICA + ECA endarterectomy surgery.18 months after surgery, carotid artery ultrasound was re examined as shown in Fig. 3D-E, and re stenosis of the carotid artery was found. Figure 3F shows: Cervical CTA shows severe stenosis of the internal carotid artery and moderate stenosis of the external carotid artery before dissection, while Fig. 3G shows relief of stenosis of the internal and external carotid arteries after dissection. Figure 3H shows readmission after 18 months of cerebral infarction, and brain Magnetic resonance imaging(MRI) shows multiple stenosis of the right internal carotid artery and middle cerebral artery.The reason for the patient's postoperative restenosis is considered to be due to irregular use of antiplatelet drugs after surgery, poor control of high-risk factors such as blood pressure and blood lipids, and failure to strictly quit smoking and drinking. After re admission to the hospital for cerebral infarction, medication treatment should be given first, followed by re-CEA or intracranial and extracranial artery bypass surgery.

Stroke can be prevented with CEA in eligible patients.［4-6］However, >70% of intraoperative surgery related strokes are due to development of an embolism from the site of surgery.［7］Intraoperative TCD monitoring can be used to detect microembolic signals (MESs) in the middle cerebral artery (MCA).［7-9］The ECA, which provides collateral blood flow to the brain, is sometimes occluded during CEA, and several investigators have emphasized the importance of ECA patency during CEA.［10-15］The importance of ECAs as the main source of collateral circulation in the brain has been well documented.Fearn et al. demonstrated that ipilateral ECA accounts for at least 10 to 15 percent of arterial blood flow in the brain in patients with severe internal carotid artery stenosis.The most important of these extracranial to intracranial compensatory collateral branches is the ECA, which is mainly reflux to the intracranial through the periorbital arterial plexus.［2，3］Occlusion of the ECA after CEA may also lead to chronic embolization or thrombosis as well as acute embolization during wound closure.［14,15］

Relevant studies have shown that monitoring middle cerebral artery blood flow by ultrasound TCD can reflect cerebral blood perfusion.The occurrence of ischemic stroke may be related to ECA stenosis. For example, in the case of ipilateral ICA and ECA stenosis, the incomplete intracranial Willis circle may lead to cerebral hypoperfusion.Nine ECA revascularization procedures were performed in symptomatic ICA occlusion patients, all of whom experienced complete remission of symptoms after surgery.Studies have shown that, first, in the case of carotid restenosis, it is necessary to maintain the patency of the external carotid artery in order to maintain the collateral pathway of cerebral perfusion, and second, it is necessary to consider ECA flow reconstruction in patients with symptomatic ipsilateral ICA occlusion.［16-19］These findings suggested that intraoperative TCD monitoring is the most practical method for detection of development of intraoperative ECA occlusion, and an additional endarterectomy for the ECA along with ICA endarterectomy is recommended when such occlusion is detected.In summary, the additional ECA endarterectomy for ECA occlusion detected by the absence of microembolic signals MESs onintraoperative TCD monitoring completely prevents development of new postoperative ischemic lesions on Diffusion weighted imaging(DWI), the difference in the incidence was 6% .In every surgical patient we studied, TCD monitoring was used during surgery, which greatly improved the safety of the surgery.

Treatment of ECA disease also increases the incidence of ischemic stroke when the ICA fails to restore blood flow, and previous studies have shown that the annual risk of recurrent stroke after non-surgical ICA occlusion is up to 20%.［14］ECA occlusion or proliferative intimal flap after CEA is a potential source of chronic thrombosis or an important source of acute thrombosis and embolism.［15］All the patients in our study showed varying degrees of improvement in middle cerebral artery blood flow monitored by TCD after surgery. 8 patients with restenosis after surgery did not take regular oral administration of antiplate and lipids, and the control of blood glucose and lipids was not ideal, and 2 patients with severe stenosis still did not quit smoking or drink alcohol.Carotid artery ultrasonography in restenosis patients showed thickening of carotid intima and uneven local echo. It was considered that carotid intimal inflammation was the main cause of recurrence.Therefore, for patients with carotid artery stenosis, it is not only necessary to completely remove the plaque after surgery, but also to regularly take medication after surgery, reasonably control blood pressure, blood lipids and blood sugar, and it is necessary to quit smoking and alcohol.

During carotid endarterectomy, every step, such as preoperative surgical strategy, intraoperative real-time TCD monitoring, intraoperative plaque stump management, and postoperative blood pressure management, is very important, because serious complications may occur in the perioperative period.［20］There is no uniform surgical method for the treatment of the external carotid artery intima.At present, the commonly used methods include: ①simple transecting of plaque at the external carotid artery opening; ②blind cutting of the inner membrane of the external carotid artery into the arterial lumen; ③The initial section of the external carotid artery was transected and the endarterectomy was performed valgus.In carotid endarterectomy, ECAs are often not treated as carefully as ICAs because most plaques are removed blind.Undoubtedly, the rationale for this is to minimize surgical time, especially the duration of carotid artery occlusion.［2］In the case of ectropion, the superior thyroid artery may be damaged and the risk of restenosis may be increased.［21］

Moore et al.［22］reported three cases of endointimal flap thrombosis in ECA after CEA, followed by anterograde embolization into ICA.Others have reported similar post-CEA neurological complications due to residual endometrial valves in the external carotid artery, or from ECA thrombosis following ECA resection.［23］Intracranial embolism was caused by anterograde thrombosis into internal carotid artery in ECA.There is no doubt that the above treatment of the external carotid artery poses a risk of ischemic stroke.Therefore, the surgical strategy formulated during our operation is that if we use bypass tube protection, we do not need to worry about the insufficiency of cerebral blood supply. In this way, the ICA and ECA can be cut simultaneously and the plaque can be completely removed, and the endometrial valve can be prevented.For non-use of the bypass protector, we usually treat the internal carotid plaque first, incise the ICA after the suture is completed, and then treat the external carotid plaque calmly.The advantage of this method is that the internal and external carotid artery plaques can be removed completely under direct vision without increasing cerebral ischemia, and the plaque stump can be carefully treated to reduce the occurrence of carotid restenosis.

Simultaneous longitudinal incision of the external carotid artery in standardized carotid endarterectomy is a safe and effective surgical method, which not only restores the normal anatomy of external carotid artery, but also has no related complications due to the exposure of blood vessels.It also potentially provides a compensatory blood flow to the intracranial outside of the cranium and indirectly increases cerebral blood perfusion.It can also effectively prevent carotid restenosis and occlusion rate, improve cerebral blood perfusion due to poor compensation of intracranial collateral circulation, and thus reduce the occurrence of ischemic stroke events.Although the sample size of this study is relatively small and needs to be further expanded, at least for now, we have confirmed that this surgical method is safe and effective and worthy of recommendation.

Ethical Approval:Research involving human participants.The study was approved by the ethics committee of the Liaocheng Second Hospital Affiliated to Shandong First Medical Universityand was performed in accordance with the ethical standard laid down in the 1964 Declaration of Helsinki and its later amendments.

Informed consent:Informed consent was obtained from all patients prior to their inclusion in the study.

Conflict of interest:The authors declare no competing interests.

Author contribution:Fuye Chen: Collection data, writing original paper.Licheng Zhang:Collection data.Tao Peng:Ultrasound evaluation. Zhenxue Xin: Paper supervision and review. Xinzhi Wang: Paper revision, supervision,communication.

Funding:This paper has no funding.

Data availability:The datasets used in this study are available from the corresponding author on reasonable request.

Archie JP Jr. The outcome of the external carotid end arterectomy during routine carotid endarterectomy. J Vasc Surg 1998; 28: 585-90.
Byrne JL, Zaman SN. External carotid endarterectomy under direct vision. Am J Surg 1989; 157: 243-4.
Fearn SJ, Picton AJ, Mortimer AJ, et al. The contribu tion of the external carotid artery to cerebral perfusion in carotid disease. J Vasc Surg 2000; 31: 989-93.
Rothwell PM, Eliasziw M, Gutnikov SA, Fox AJ, Taylor DW, Mayberg MR, et al. Analysis of pooled data from the randomised controlled trials of endarterectomy for symptomatic carotid stenosis. Lancet 2003;361:107-16.
Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. Endarterectomy for asymptomatic carotid artery stenosis. JAMA 1995;273:1421-8.
North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med 1991;325:445-53.
Spencer MP. Transcranial Doppler monitoring and causes of stroke from carotid endarterectomy. Stroke 1997;28: 685-91.
Ackerstaff RG, Moons KG, van de Vlasakker CJ, Moll FL, Vermeulen FE, Algra A, et al. Association of intraoperative transcranial Doppler monitoring variables with stroke from carotid endarterectomy. Stroke 2000;31:1817-23.
Wolf O, Heider P, Heinz M, Poppert H, Sander D, Greil O, et al.Microembolic signals detected by transcranial Doppler sonography during carotid endarterectomy and correlation with serial diffusion-weighted imaging. Stroke 2004;35: e373-5.
Fearn SJ, Picton AJ, Mortimer AJ, Parry AD, McCollum CN. The contribution of the external carotid artery to cerebral perfusion in carotid disease. J Vasc Surg 2000;31:989-93.
van Everdingen KJ, Visser GH, Klijn CJ, Kappelle LJ, van der Grond J. Role of collateral flow on cerebral hemodynamics in patients with unilateral internal carotid artery occlusion. Ann Neurol 1998;44:167-76.
Vernieri F, Pasqualetti P, Matteis M, Passarelli F, Troisi E, Rossini PM, et al. Effect of collateral blood flow and cerebral vasomotor reactivity on the outcome of carotid artery occlusion. Stroke 2001;32:1552-8.
van Laar PJ, van der Grond J, Bremmer JP, Klijn CJ, Hendrikse J. Assessment of the contribution of the external carotid artery to brain perfusion in patients with internal carotid artery occlusion. Stroke 2008;39:3003-8.
Paty PS, Adeniyi JA, Mehta M, Darling RC 3rd, Chang BB, Kreienberg PB, et al. Surgical treatment of internal carotid artery occlusion. J Vasc Surg 2003;37:785-8.
Ascer E, Gennaro M, Pollina RM, Salles-Cunha S, Lorenson E, Yorkovich WR, et al. The natural history of the external carotid artery after carotid endarterectomy: implications for management. J Vasc Surg 1996;23:582-5.
Gertler JP, Cambria RP. The role of external carotid endarterectomy in the treatment of ipsilateral internal carotid occlusion: collective review. J Vasc Surg 1987;6:158-67.
Archie JP Jr. Management of the external carotid artery during routine carotid endarterectomy. J Cardiovasc Surg 1991;33:62-4.
McIntyre KE Jr, Ely RL, Malone JM, Bernhard VM, Goldstone J. External carotid artery reconstruction: its role in the treatment of cerebral ischaemia. Am J Surg 1985;150:58-64.
Sterpetti AV, Schultz RD, Feldhaus RJ. External carotid endarterectomy: indications, technique, and late results. J Vasc Surg 1988;7:31-7.
Papanicolaou G, Toms C, Yellin AE, et al. Relation ship between intraoperative color-flow duplex findings and early restenosis after carotid endarterectomy: a preliminary report. J Vasc Surg 1996; 24: 588-96.
Ascher E, Hingorani A, Markevich N, et al. Carotid surgery without external carotid endarterectomy: a 6-year clinical experience with 1027 cases. Eur J Vasc Endovasc Surg 2003; 25: 458-61.
Moore WS, Martello JY, Quifiones-Baldrich WG, Ahn SS.Etiologic importance of the intimal flap of the external carotid artery in the development of postcarotid endarterectomy stroke. Stroke 1990;21:1497-502.
Countee RW, Vijayanathan T, Wu SZ. External carotid occlusion as a cause of recurrent ischemia after carotid endartercc[1]tomy. Neurosurgery 1982;11:518-21.

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Effectiveness of simultaneous longitudinal incision of the external carotid artery in standardized carotid endarterectomy

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