Carotid endarterectomy: a saga of clinical science, personalities, and evolving technology: the Willis lecture

Carotid Stenosis and Stroke: Historical Perspectives Leading to Current Challenges

The carotid artery is unique; it is the only vessel to bifurcate into a bulb larger than itself. The history of its anatomic description, understanding of its pathophysiology and evolution of its imaging are relevant to current controversies regarding measurement of stenosis, surgical/endovascular therapies and medical management of carotid stenosis in stroke prevention. Treatment decisions on millions of symptomatic and asymptomatic patients are routinely based on information from clinical trials from over 30 years ago. This article briefly summarizes the highlights of past research in key areas and discuss how they led to current challenges of diagnosis and treatment.

[A 20-year experience in surgical treatment of steno-occlusive lesion of craniocervical arteries at the Burdenko Neurosurgical Center]

INTRODUCTION

Surgical treatment of cerebral ischemia at the Burdenko Neurosurgical Center for the period from 1999 to 2019 is analyzed in the paper. The details of the treatment strategy in patients with steno-occlusive lesion of craniocervical arteries followed by cerebral ischemia developed over 20 years are discussed in the article. We have analyzed the features of surgical interventions on the major craniocervical arteries in a neurosurgical clinic and the results of this treatment.

OBJECTIVE

To demonstrate management of various lesions of major cerebral arteries in modern neurosurgical vascular hospital.

MATERIAL AND METHODS

In total, there were 3098 interventions on the major cerebral arteries in 2527 patients for this period. Mean age of patients ranged from 1.5 to 91 years (58±14 years). Interventions included open reconstructions of the carotid arteries (2031 surgeries), reconstructions of the vertebrobasilar arteries (135 surgeries), brain revascularization (658 surgeries), excision of the tumors of neurovascular bundle on the neck compressing carotid arteries (51 interventions). Endovascular interventions were performed in 223 cases and consisted of angioplasty and stenting of the extracranial segments of craniocervical arteries (185 surgeries), stenting of the intracranial arteries (30 surgeries) and endovascular thrombextraction (8 cases). Staged surgeries were performed in 541 patients (22.3%).

RESULTS

Favorable outcomes were obtained in 87.6% of cases, satisfactory results - in 9% of patients. Clinical deterioration due to long-term postoperative complications and recurrent strokes occurred in 2.9% of cases. Postoperative morbidity rate was 4.6%, persistent neurological deficit developed in 2.6% of cases. Mortality rate was 0.5%.

CONCLUSION

Surgical treatment of stenotic and occlusive lesion of the major cerebral arteries is an interdisciplinary problem. Solution of this issue is closely associated with technological progress, new discoveries in normal and pathological physiology, as well as clinical researches. Individualized choice of surgical approach is one the main modern trends of neurosurgical approach to this problem. At the same time, own surgical experience is the most important factor determining the results of arterial reconstructions.

Carotid Endarterectomy: Outcome of “Old-Fashioned” Approach

The purpose of this study is to assess the 30-day postoperative incidence of death, myocardial infarction, stroke, wound complication, and cranial nerve damage after carotid endarterectomy using induced hypertension (systolic pressure ≥160 mmHg), selective shunting, and primary closure. We retrospectively analyzed the records of 206 patients who underwent a total of 239 carotid endarterectomy surgeries between January 2002 and August 2009 to identify the impact of selective shunting and primary closure on morbidity and mortality. Two hundred thirty-nine surgeries were performed on 206 patients. The study population was 55% men and 45% women with average age of 67 years (range 33–85 years). Of these patients, 181 had hypertension (88%), 82 had diabetes (40%), 73 had peripheral vascular disease (35%), 107 had coronary artery disease (52%), 142 had tobacco abuse (69%), and 146 had dyslipidemia (71%). Twenty-six patients (13%) presented with history of stroke, 77 (37%) with transient ischemic attack (TIA), 14 (7%) with amaurosis fugax, and 108 (52%) were asymptomatic. The average internal carotid stenosis was 74% as indicated by duplex, computed tomography, magnetic resonance imaging, or angiogram. Of the 239 surgeries, 3 (1%) required patch closure, and 7 (3%) required shunt. Thirty-day postoperative complication rates are as follows: stroke, 3 (1.3%); TIA, 4 (1.7%); bleeding, 5 (2.1%); superficial wound infection, 2 (0.8%); heart attack, 1 (0.4%); cranial nerve injury, 0; and hospital death, 0. One patient (0.4%) died at home from an unknown cause. In conclusion, carotid endarterectomy with selective shunting and primary closure is a safe and effective surgical means of preventing stroke.

Chapter 27: a history of cerebrovascular disease

Stroke is central to the history of cerebrovascular disease. References to this condition already appear in the Hippocratic corpus, referred to as apoplexy, which was defined by the clinical presentation: a sudden collapse, a loss of consciousness, a lack of movement, and included a variety of pathologies. A humoral imbalance was seen as the causation. In the 17th century, Johannes Wepfer, a Swiss physician, first demonstrated that apoplexy was caused by an intracranial hemorrhage; Thomas Willis, an English anatomist, explored the role of the cerebral arteries. Stroke became a cerebrovascular disease. By the 19th century, based on extensive clinico-pathological correlates initiated at the Paris Medical School, a vascular basis was firmly established and a range of pathologies determined. Apoplexy was considered too imprecise, and the term abandoned in favor of the term "cerebro-vascular accident" and latterly stroke. Although physicians of the 19th century utilized a wide variety of therapies in the treatment of stroke, with particular emphasis on blood letting, therapeutic nihilism dominated stroke management well into the 20th century. Following the mid 20th century work by C. Miller Fisher, with the recognition of the importance and the therapeutic implication of the carotid artery in stroke, the specialty of stroke medicine came into being. Therapeutic nihilism was replaced by an increasing armamentarium of therapeutic interventions.

Evolving treatment strategies for carotid artery stenosis

Internal carotid artery stenosis is an important cause of ischemic stroke. Treatment decisions frequently center on whether the patient is symptomatic or asymptomatic. For recently symptomatic patients with severe stenosis (70% to 99%) and low to medium surgical risk, carotid endarterectomy (CEA) is extremely useful for stroke prevention. CEA is moderately useful for patients with 50% to 69% symptomatic stenosis and is not indicated for patients with symptomatic stenosis of less than 50%. CEA may be useful for select patients with severe asymptomatic stenosis (80% to 99%) but only if the surgical complication is kept below the 3% level. Carotid stenting is an emerging option for the future but is still experimental. In addition to carotid intervention, patients with carotid stenosis should receive aggressive risk factor management, including treatment with antiplatelet agents and statins.

Comparison between the NASCET method and subjective visual impression in the evaluation of internal carotid artery stenosis

OBJECTIVE

To evaluate the accuracy of subjective visual impression (SVI) of an experienced neuro-radiologist in the measurement of the degree of internal carotid artery (IC) stenosis evaluated by digital angiography (DGA).

METHOD

Ten symptomatic patients with internal carotid stenosis greater than 70% in a previous duplex scan were submitted to DGA. The degree of stenosis in both sides (symptomatic and asymptomatic) were evaluated by the same neuro-radiologist who gave his SVI and applied the NASCET method immediately after. Both methods were compared using the intraclass correlation coefficient (r) and its 95% confidence interval (95% ci). For each method, the sample (20 ICs) was also divided in surgical (stenosis between 70 and 99%) and non surgical ICs, using kappa concordance coefficient (k) to compare the results.

RESULTS

The results comparing the 20 values obtained by each method are: r = 0.90 (95% ci: 0.77-0.96). Dividing the sample in surgical and non surgical ICs, k = 0.857, p < 0.0001; sensitivity = 100% (39.6%-100%); specificity = 93.8% (67.7%-99.7%); positive predictive value = 80% (29.9%-98.9%); negative predictive value = 100% (74,7%-100%).

CONCLUSION

The SVI may be used by at least some experienced neuroradiologists as a preliminary tool to evaluate the degree of IC stenosis with DGA, but a standardised and well established method should be routinely performed.