STA–MCA bypass for symptomatic carotid occlusion and haemodynamic impairment

doi:10.1016/j.jocn.2008.01.022

Journal of Clinical Neuroscience

Volume 16, Issue 2, February 2009, Pages 226-235

https://doi.org/10.1016/j.jocn.2008.01.022 Get rights and content

Abstract

Patients with carotid artery occlusion and haemodynamic insufficiency have a high risk of stroke. Cerebral revascularization surgery improves cerebral blood flow, but it remains unclear whether this reduces the risk of stroke. This study assesses the long-term outcome of patients undergoing superficial temporal artery to middle cerebral artery (STA–MCA) bypass for symptomatic carotid occlusion. The long-term clinical follow-up and haemodynamic reserve, measured by ⁹⁹Technetium single photon emission computed tomography (Tc99 SPECT) scan with acetazolamide challenge, were reviewed for 19 consecutive patients before and after STA–MCA bypass. The stroke rate after bypass surgery was 8% per year. In patients waiting for surgery, the stroke rate was 18% per year. Cerebral perfusion assessed with SPECT scan improved in 88% of patients. These results are consistent with the high risks of haemodynamic infarction in untreated patients and a benefit from revascularization surgery. The percentage annual stroke risk compares favourably with an 18% rate reported for patients with internal carotid artery occlusion and impaired cerebrovascular reserve.

Introduction

There is a group of patients with symptomatic carotid occlusion in whom the symptoms and imaging findings suggest a haemodynamic rather than embolic cause of ischemia. Prospective studies of such patients report that those with impaired haemodynamics have an annual risk of stroke of between 8% and 36% which is significantly higher than in patients with normal haemodynamics (0–6%).[1], [2], [3], [4], [5], [6], [7], [8] In these patients, improving the cerebral blood supply by an external to internal carotid artery bypass (EC–IC bypass) improves the haemodynamic reserve.[9], [10], [11], [12] Bypass surgery remains controversial, however, because a clinical benefit has not been proven.

We describe the clinical presentation, management and outcome of 19 patients who underwent EC–IC bypass for symptomatic carotid occlusion and impaired cerebrovascular reserve (CVR), detected by single photon emission computed tomography (SPECT) and acetazolamide challenge.

Section snippets

Patient characteristics and clinical management

From January 2000 to January 2006, 31 patients were referred for consideration of bypass surgery. Five patients had symptomatic carotid occlusion but did not have significant acetazolamide-induced perfusion reduction. Three patients were seen with abnormal SPECT scans but unclear symptomatology. These patients were not offered surgery. Twenty-two patients presented with symptomatic carotid occlusion and haemodynamic compromise detected by SPECT scan. Eighteen of these patients underwent

Patient 13

This 50-year-old man presented with a left hemiparesis due to cerebral infarction. Carotid angiography demonstrated occlusion of the right internal carotid artery (ICA) secondary to dissection, intracavernous stenosis of the left ICA, and poor collateral circulation (Fig. 2). MRI demonstrated an internal watershed pattern of ischemia consistent with haemodynamic rather than embolic pathology and the SPECT scan demonstrated right hemispheric steal (Fig. 1). A right STA–MCA anastomosis was

Discussion

In patients with symptomatic carotid occlusion and impaired haemodynamic reserve the stroke rate per year with medical management alone is about 18% (Table 2) compared to about a 3% yearly risk in patients with normal haemodynamics. In our patient series, there were four post-operative strokes in 52 years of patient follow-up, for an annual risk of stroke of 7.6%.

In spite of not having a true control group, we are still able to compare our patients with others. During the time on the waiting

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Cited by (23)

Extracranial-Intracranial Cerebral Revascularization for Atherosclerotic Vessel Occlusion: An Updated Systematic Review of the Literature
2023, World Neurosurgery
Atherosclerotic steno-occlusive cerebrovascular disease includes extracranial carotid occlusive and intracranial atherosclerotic disease. Despite the negative findings in Carotid Occlusion Surgery Study (COSS), many large centers continue to report favorable results for revascularization surgery in select groups of patients. The aim of our study was to perform an updated systematic review to investigate the role of revascularization surgery for atherosclerotic steno-occlusive patients in the modern era.
Five independent reviewers performed Preferred Reporting Items for Systematic Reviews and Meta-Analyses–guided literature searches in October 2022 to identify articles reporting clinical outcomes in adult patients undergoing bypass for atherosclerotic steno-occlusive disease. Primary endpoints used were perioperative and long-term ischemic strokes, intracerebral hemorrhage, bypass patency, and favorable clinical outcomes. Study quality was evaluated with Newcastle-Ottawa, JADAD, and the Oxford Center for Evidence-Based Medicine scales.
A total of 6709 articles were identified in the initial search. Of these articles, 50 met the inclusion criteria and were included in the systematic review. A notable increase in the proportion of articles published over the past 10 years was observed. There were 6046 total patients with 4447 bypasses performed over the period from 1978 to 2022. The average length of follow-up was 2.75 ± 2.71 years. The average Newcastle-Ottawa was 6.23 out of 9 stars. There was a significant difference in perioperative stroke (odds ratio [OR], 0.65 [0.48–0.87]; P = 0.004), long-term ischemia (OR, 0.32 [0.23–0.44]; P < 0.0001), overall ischemia (OR, 0.36 [0.28–0.44]; P < 0.0001), and favorable outcomes (OR, 3.63 [2.84–4.64]; P < 0.0001) when comparing pre-COSS to post-COSS time frames in favor of post-COSS.
Based on a systematic review of 50 articles, the existing literature indicates that long-term stroke rates and favorable outcomes for surgical revascularization for steno-occlusive disease have improved over time and are lower than previously reported. Improved patient selection, perioperative care, and surgical techniques may contribute to improved outcomes.
Change in brain perfusion after extracranial-intracranial bypass surgery detected using the mean transit time of computed tomography perfusion
2012, Journal of the Chinese Medical Association
Citation Excerpt :
99Technetium single-photon emission computed tomography (Tc99 SPECT) scans with acetazolamide challenge have been used to evaluate EC-IC bypass surgery.2,3 Jeffree and Stoodley evaluated 19 patients, 88% of whom showed improvement in cerebral perfusion after EC-IC bypass surgery.2 Schmiedek et al evaluated 28 patients who suffered from hemodynamic cerebral ischemia with significant impairment of cerebrovascular reserve capacity.3
Cerebral perfusion can be evaluated using a computed tomography (CT) scan by intravenous bolus injection of contrast media. The purpose of this study was to investigate the value of CT perfusion (CTP) in follow-up of extracranial–intracranial (EC-IC) bypass surgery.
We retrospectively reviewed pre- and postoperative CTP studies in 14 patients who received EC-IC bypass surgery because of cerebral arterial occlusion or stenosis. Brain areas showing prolongation of the mean transit time (MTT) were automatically identified and quantitatively measured.
All 14 patients showed MTT prolongation in the preoperative CTP study. In 13 patients, a reduction in brain volume with MTT prolongation was noted during postoperative CTP. These 13 patients had a patent EC-IC anastomosis, and 42 ± 21% of the brain area with MTT prolongation returned to normal MTT during CTP 7 ± 4 days (range 2–13 days) after surgery. On clinical follow up of 41 ± 16 months (range 14–60 months), no stroke or transient ischemic attack was noted after bypass surgery in these 13 patients. The brain volume with MTT prolongation did not decrease in just one patient whose EC-IC anastomosis was not patent, and the patient suffered a minor stroke during surgery.
Quantitative results for the brain area with MTT prolongation were positively correlated with improvement in brain perfusion shown on MTT, EC-IC bypass patency, and patient outcome.
The practice of knots untying technique using a 10-0 nylon suture and gauze to cope with technical difficulties of microvascular anastomosis
2011, World Neurosurgery
Citation Excerpt :
Microvascular anastomosis is an essential technique for treating ischemic strokes in the neurosurgical field (3) that can be also applied for a variety of indications such as treatment of complex cerebral aneurysms (7, 8) or tumors involving the main cerebral arteries (7). For the extracranial-to-intracranial (EC-IC) bypass, the superficial temporal artery is often used as a preferred donor artery, and the middle cerebral artery is most frequently chosen as a revascularized recipient (4). Because brain tissue is quite sensitive to ischemic change, the ischemic brain requiring surgical revascularization is more vulnerable to the risk of irreversible complication with transient occlusion of the recipient arteries during anastomosis.
We report a training technique of microvascular anastomosis readily accessible for trainees engaged in busy day-to-day clinical practice.
A table-top microscope is prepared on a table and 10-0 nylon suture (nonsterile) is used to tie two adjacent gauze fibers to form successive knots. In a second step, the knots are untied using the suture needle, which we call the knots untying technique (KUT). As the tied knots face different directions, it is difficult to guide the needle accurately through the knots without damaging or breaking the suture. And to untie all the knots within a certain time period, high controllability is required.
The practice of KUT will allow surgeons to improve their ability to accurately guide the needle from any direction and carry out precise suturing swiftly, which will prevent vascular wall dissection during microvascular anastomosis or inability to guide the needle to a target point because of physiologic tremor.
In our experience of training young neurosurgeons, practice of KUT contributes to shortening the duration of blood-flow blockage and helps mastering the technique of successful microvascular anastomosis.
Functional Occlusions of the Carotid Artery (String Signs). To Treat or Not to Treat?
2010, JACC: Cardiovascular Interventions
Outcomes of Arterial Bypass for Posterior Circulation Atherosclerosis: A Case Series
2023, Operative Neurosurgery
Bibliometric and visual analysis of cerebral revascularization from 1999 to 2022
2023, Frontiers in Neuroscience

View all citing articles on Scopus

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Clinical StudySTA–MCA bypass for symptomatic carotid occlusion and haemodynamic impairment

Abstract

Introduction

Section snippets

Patient characteristics and clinical management

Patient 13

Discussion

J Neurol Sci

J Neurol Sci

Count-based PET method for predicting ischemic stroke in patients with symptomatic carotid arterial occlusion

Radiology

Importance of hemodynamic factors in the prognosis of symptomatic carotid occlusion

JAMA

Acetazolamide reactivity on 123I-IMP single photon emission computed tomography in patients with major cerebral artery occlusive disease: correlation with positron emission tomography parameters

J Cereb Blood Flow Metab

Detection of misery perfusion with split-dose 123I-iodoamphetamine single-photon emission computed tomography in patients with carotid occlusive diseases

Stroke

Severely impaired cerebrovascular reactivity predicts stroke and TIA risk in patients with carotid artery stenosis and occlusion

Brain

Identification of hemodynamic compromise by cerebrovascular reserve and oxygen extraction fraction in occlusive vascular disease

J Cereb Blood Flow Metab

Evidence of misery perfusion and risk for recurrent stroke in major cerebral arterial occlusive diseases from PET

J Neurol Neurosurg Psychiatry

[Can EC–IC bypass prevent brain ischemia from recurring?]

No Shinkei Geka

[133Xe-DSPECT: significance of the cerebrovascular reserve capacity for the diagnosis and therapy of chronic cerebral ischemia]

Nuklearmedizin

STA–MCA bypass in bilateral carotid artery occlusion: clinical results and long-term effect on cerebrovascular reserve capacity

Neurol Res

Improvement of cerebrovascular reserve capacity by EC–IC arterial bypass surgery in patients with ICA occlusion and hemodynamic cerebral ischemia

J Neurosurg

Improving the assessment of outcomes in stroke: use of a structured interview to assign grades on the modified Rankin Scale

Stroke

Long-term prognosis of medically treated patients with internal carotid or middle cerebral artery occlusion: can acetazolamide test predict it?

Stroke

Long-term follow-up of asymptomatic patients with major artery occlusion: rate of symptomatic change and evaluation of cerebral hemodynamics

AJNR Am J Neuroradiol

Clinical Study
STA–MCA bypass for symptomatic carotid occlusion and haemodynamic impairment