Carotid artery stenting without post-stenting angioplasty in patients with high risk for reperfusion injury (technical modification)

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Mona Ali Eissa, 3. Alia H.Mansour, 4. Mohamed Khaled Elewa This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6506729/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Cerebral Hyper perfusion Syndrome (CHS) is an ominous complication that can follow extracranial carotid artery revascularization. The most dangerous consequence of CHS is Hyperperfusion-Induced Cerebral Hemorrhage (HICH), which boasts a staggering mortality of 75%. The pathophysiology of HICH is thought to be disruption of cerebral autoregulation mechanisms in hypo-perfused brains, leading to a disastrous cerebral blood flow rise. Several risk factors have been reported for HICH, such as: Hypertension, Severe carotid artery stenosis (>90%), Poor collaterals, Contralateral carotid disease, and recent cerebrovascular events. Even though strict blood pressure control is the only established method of prevention of CHS, new evidence suggests that staged carotid artery stenting (CAS) can also offer additional preventive benefits by facilitating gradual reconstitution of cerebral blood flow. In this retrospective study, we examined the efficacy of a staged CAS approach. We performed stent alone without performing an angioplasty in the initial session, making use of the stent's radial force to gradually restore blood flow. Follow-up angiographic evaluation was used to identify candidates for a second-stage angioplasty. Results Retrospective analysis was done in high-risk patients with extracranial carotid artery stenosis who underwent carotid artery stenting (CAS) without post-stenting angioplasty. The study evaluated the effectiveness of stent self-expansion in re-establishing cerebral perfusion and the clinical evidence of hyperperfusion or hypoperfusion. Follow-up cerebral angiography detected those patients requiring additional treatment with angioplasty. After deployment of stent without immediate post-angioplasty, a residual stenosis of <30% was seen in 10 cases (29.41%). Permissive residual stenosis of 30% to 50% was allowed to avoid the risk of reperfusion injury in the other 24 cases (70.59%). After 1 month follow-up, 44.12% (15/34) of cases required second-stage angioplasty and 55.88% (19/34) of cases were successfully treated with stenting alone, with a decrease in stenosis to <30%. Interestingly, 13/19 (68.4%) of them belonged to the permissive stenosis group. That was, however, statistically non-significant (Chi2 =0.1, p=0.755). Conclusion As a safeguard against the hyperperfusion syndrome, the carotid stent's self-expanation criteria can be used to progressively restore blood flow to the hypoperfused brain. Figures Figure 1 Figure 2 Background Carotid artery stenosis is the etiology of 15–20% of cerebrovascular ischemic strokes ( 1 ). Endovascular carotid artery stenting (CAS) is currently an accepted treatment alternative to carotid endarterectomy (CEA) with comparable outcomes ( 2 ). Cerebral hyperperfusion syndrome (CHS) remains a serious complication following extracranial carotid artery revascularization. CHS is characterized by a > 100% increase in cerebral perfusion above baseline levels ( 3 – 5 ) with an incidence ranging from 0.5–6.8% ( 6 ). Clinical presentations vary from migraine-type headache, seizures, and focal deficits, while radiological presentation may vary from normal to brain edema, subarachnoid hemorrhage, and intracerebral hemorrhage. Of interest, hyperperfusion-induced cerebral hemorrhage (HICH) carries a 75% mortality ( 6 ). The pathophysiology of CHS is theorized to be a result of derangement of cerebral autoregulation mechanisms within hypoperfused brains. Risk factors proven for CHS are hypertension, > 90% carotid artery stenosis, unfavorable collaterals, contralateral carotid disease, and recent stroke ( 7 ). While strict blood pressure control is the only method that is proven to be preventive, there have been recent descriptions of staged CAS being beneficial in terms of stepwise revascularization of cerebral circulation ( 8 ). This retrograde investigation had an innovative technique of stenting only without the immediate use of post stenting angioplasty within a single setting. The follow up angiographic assessment determining whether second-stage angioplasty is indicated. Methods Following ethical committee approval, informed consent was obtained from patients for publication of their data. We identified patients with high risk for CHS and underwent Carotid artery stenting without post-stenting angioplasty retrospectively from our medical records between 2016 and 2024. The inclusion criteria were one or more of the factors implicated in a high risk of hyperperfusion injury ( 6 , 9 , 10 ), and these included: Age ≥ 70 years, Diabetes mellitus, Chronic hypertension, chronic subtotal occlusions, Contralateral stenosis or occlusion, Extensive leukoaraiosis (Fazekas 3) ( 11 ),recent stroke ,reperfusion within 2 weeks of the acute stroke, and Moderate to severe stroke. All patients received aspirin (325 mg/day) and clopidogrel (75 mg twice daily) for 7 days prior to the elective procedure ( 12 ). Antihypertensive medication was discontinued the night before. Conscious sedation was given to patients, and they were positioned in the supine position with bilateral groin area draping. Trans-femoral arterial diagnostic cerebral angiography was performed to evaluate the carotid lesion, vascular anatomy, and tandem lesions. Then a 5 French femoral sheath was exchanged for an 8 French 90 cm sheath for stability. Systemic heparinization was achieved with intravenous heparin (50–70 units/kg), as confirmed by activated coagulation time (ACT) of 250–350 seconds. After that, the guiding catheter was advanced to the distal half of the common carotid artery (CCA) followed by a micro wire (0.014 inch) across the lesion for distal access. The critical stenosis were pre-dilated with an undersized balloon angioplasty so that the distal embolic protection device may be delivered through. Atropine IV (0.75) was utilized as prophylactic against bradycardia. Then distal embolic protection device was implanted in the distal cervical internal carotid artery. Using the road roadmap guidance, slowly released self-expandable stent with no post-stenting angioplasty. The distal embolic protection device was removed and inspected for trapped emboli. Finally, last angiographic run was performed to exclude stent thrombosis or distal cerebrovascular strokes. The femoral sheath was removed 8 hours later in the intensive care unit (ICU). All patients were closely monitored in the ICU for 48 hours for cerebrovascular and cardiovascular events. At discharge, patients resumed their usual medications, with the addition of 90 days of clopidogrel and lifelong aspirin therapy. Outpatient follow-up included clinical monitoring for symptoms and signs of hypo-perfusion or hyper-perfusion. Radiological follow-up was done initially with conventional angiography to determine residual stenosis according to NASCET criteria. Second-stage angioplasty was indicated if stenosis exceeded 50%. Subsequent follow-up, for at least 2 years, included both clinical and radiological assessment with carotid duplex ultrasound. Data were statistical analyzed and Categorical data were presented as numbers and percentages. Chi-square test Used to test the significance between the different stages. For continuous data, they were tested for normality by Shapiro-Wilk test. Quantitative data were shown as range (minimum and maximum), mean, standard deviation and median. Pearson correlation to compare between more than two time periods or phases. Significance of the results obtained was assessed at the 5% level. Results Thirty four (34) patients form our study population is under normal distribution. While Males (25 patients) capture 73.53% sample size, female gender (9 patients) participated by 26.47%. Ages were of 49–83 years and Mean was of 65.06 ± 8.42 for standard deviation. Clinical risk factors of patients for hyper reperfusion syndrome was shown in table (1, 2). Hypertension, hypercholesterolemia and diabetes mellitus were the most prevalent comorbidities and contributed by 76.47%, 67.65%, and 61.76% respectively. Earlier stroke patients were categorized based on national institute health (NIH) as minor stroke NIH ( 1 – 4 ) (26.47%), and moderate stroke NIH ( 5 – 15 ) (50%). none of our patients had Sever stroke. Transient ischemic attacks and amauraosis were observed in 20.59%, and 2.94% respectively. Our study population demonstrated sever ICA stenosis (stenosis more than 70%) in all the participants. Subtotal occlusion were found in 15 cases (38.24%) of them (hair line residual lumen and delayed intracranial ICA distal contrast filling). Two major causes were seen to produce the stenosis: atherosclerotic in 31 cases (91.18%) and dissection in 3 patients (8.82%). Atherosclerotic lesion was indicated by plaque calcification and ulceration in 9 patients (26.47%) and 5 patients (14.71%) respectively. Other radiological risk factors manifested in (Table 3 ).Although pre-stenting angioplasty was done in all. In 14 of 34 cases (41.18%) protective filters were used with high risk of thromboembolic complications. Less than 30% residual stenosis was left in 10 cases (29.41%) after stent deployment without post angioplasty. Permissive residual stenosis of 30–50% was allowed to avoid the risk of reperfusion injury in the remaining 24 cases (70.59%). (Table 4 ) Table 1 comorbidities risk factors Parameter Frequency % of Cases Age > 80 years 3 8.82% HTN 26 76.47% hypercholesterolemia 23 67.65% DM 21 61.76% CAD/PVD 17 50% smoking 10 29.41% CRD 5 14.71% cardiomyopathy 3 8.82% AF 2 5.88% CLD 2 5.88% HTN (hypertension), DM (diabetes mellitus), CAD (coronary artery disease), PVD (peripheral vascular disease), CRD (chronic kidney diseases), AF (atrial fibrillation), CLD (chronic lung diseases). Table 2 History of previous hypo perfusion manifestation (old ischemic events) more than 2 weeks before intervention Parameter Frequency Percentage Moderate stroke NIH ( 5 – 15 ) 17 50% minor stroke NIH ( 1 – 4 ) 9 26.47% TIA 7 20.59% amaurosis 1 2.94% severe stroke 0 0% NIH (neurological institute of health scale for stroke evaluation), TIA (transient ischemic attack) Table 3 Radiological risk factors for reperfusion injury Radiological findings Frequency % of Cases high grade stenosis 34 100% Atherosclerosis 31 91.18% subtotal occlusion 13 38.24% plaque calcification 9 26.47% extensive leukoaryosis (Fazekas 3) 7 20.59% contralateral stenosis 6 17.65% plaque ulceration 5 14.71% contralateral occlusion 3 8.82% carotid dissection 3 8.82% Distal Tandem lesion 3 8.82% microbleds 2 5.88% Table 4 procedural specification Parameter frequency Prestenting angioplasty 34 case (100%) Using filter 14 out 34 cases (41.18%) Residual stenosis >30% AND < 50% Less than 30% 24 cases (70.59%) 10 cases (29.41%) No complication was seen during the procedure or at the immediate and remote follow up in a 2 -year- duration. Fifteen cases (44.12%) had a second stage angioplasty after a month. the stenting alone effectively treated the stenosis to below 30% in 19 patients (55.88%) significantly 13 patients (38.24%) were from the permissive stenosis group. But that was not statistically significant (Chi2 = 0.1, p = 0.755) Table 5 . The Mean MRS ± Std. before intervention was (1.71 ± 1.22) while in follow- up was (1.35 ± 1.2). Their relationship at the last follow up was statistically significant, r (32) = 0.88, p = 30% AND < 50% 11 32.35% 13 38.24% 24 70.59% Residual stenosis < 30 4 11.76% 6 17.65% 10 29.41% 15 44.12% 19 55.88% 34 100% Cases Case 1 69 year old male presented with history of recurrent transient ischemic attacks, cerebral angiogram showed right ICA high grade stenosis and left internal carotid artery (ICA) occlusion. He was treated with right translunar CAS without angioplasty. Residual after post stent deployment was 50%. Patient was discharged on dual antiplatelet. On follow up after one month, cerebral angiogram showed improvement in the stenosis to be less than 30% and hence no need for second stage angioplasty (Fig. 1). Case 2 71 years old male history of left water shed area infarctions in left cerebral hemisphere. His cerebral angiography was demonstrating left ICA subtotal stenosis, after stent deployment the residual stenosis was 50%. On follow up angiogram done after 1 month the stenosis was raised to be 70%. Hence balloon angioplasty was done and residual stenosis was below 10%. (Fig. 2 ) Discussion Hyperperfusion phenomenon (HPP) is referred to as an elevation in cerebral blood flow by over 100% than the base line when measured by transcranial Doppler ( 13 ) or over 120% asymmetry index in cerebral blood flow (CBF) in relation to the normal side on CT perfusion (CTP). Hyper-perfusion syndrome (HPS) is used to refer to the development of clinical symptoms due to these changes. Even though this condition was initially described in 1981 as clinical syndrome of migarine like, transient focal seizure, and intracerebral hemorrhage appearance after carotid endarterectomy ( 14 ), various other clinical presentations have been described. This is a state of strict definition of hemispheric neurological defect or seizure to occur after cerebral revascularization. It is ipsilateral to the artery that has been revascularized, is independent of thromboembolism, and there is no sign of new infarction on diffusion weighted MRI scans. MRI or CT Perfusion scans would show hyperperfusion of the ipsilateral hemisphere ( 15 ). HPS is most often associated with greater than 90% internal carotid artery (ICA) stenosis. Other significant risk factors are severe Contralateral ICA stenosis, poor collateral Flow, hypertension, and recent stroke. The higher the risk Factors, the higher the incidence ( 7 ). HPS risk factors are determined using clinical and radiological criteria. We defined our inclusion criteria from clinical presentations of patients and demonstration of carotid stenosis greater than 90%, poor collaterals and contralateral ICA stenosis. We did not employ cerebral perfusion tests or challenge tests to identify which of the patients examined had impaired auto regulatory mechanisms since these are expensive and not readily available. Prevention and HPS management continue to be contentious with agreement being control of blood pressure ( 16 ). While we were successful in keeping our patients' systolic blood pressure 20% below their base-line, we could not verify or disprove whether this therapy had any effect on the hyper -perfusion phenomenon. This is because of the absence of transcranial Doppler and perfusion images during the immediate follow -up period. Certain authors have reported the staged carotid artery stenting procedure as another way to reduce the incidence of CHS. At the first stage, balloon angioplasty was performed followed by stenting after a month in a second stage ( 7 , 17 ). The Stenting-alone procedure was reported to overcome the embolic complication of carotid angioplasty as well as rectify the stenosis by virtue of the self-expanding character of the stent ( 18 , 19 ). This technique relies on observation of progressive dilation of an obstructive malignant biliary stricture by self-expanding stenting alone without angioplasty in the days after the procedure ( 18 , 20 ).Nevertheless the authors of the initial report intended to reduce embolic complications. The population features in their study were not comparable with our patients with the exception of severe carotid stenosis. We initially pre stented in our experience, then stenting alone without initial angioplasty to allow the radial force of the stent to open up the blood supply slowly. On follow-up, when ICA stenosis by NACET criteria exceeded 70%, angioplasty was done. Even though stent carotid choice is based on factors such as trackability, scaffolding of atheromatous plaques and radial force to achieve maximal patency, we employ various types of self-expanding stents such as Acculink (Guidant, Santa Clara, California), Protégé (ev3, Plymouth, Minnesota), and carotid Wallstent (Boston Scientific, Natick, Massachusetts) based on their availability. Although the Protégé stent (ev3, Plymouth, Minnesota) was reported to have maximum radial force properties, its open cell structure must be employed with care in combination with distal protection devices to prevent distal emboli ( 21 ). In very tight stenosis we crossed the lesion with steerable micro-wires of 0.010 and 0.014 diameters such as Synchro (Stryker Neurovascular) and The Traxcess (Microvention). We used pre stenting angioplasty in all the cases as crossing these lesions directly with stent delivery catheter was reported to have embolic complications or dissections ( 17 , 18 ). Distal embolic devices were used in the setting of subtotal occlusion and plaque ulceration to prevent distal showering in 14 out of 34 cases 41 (18%). By one month the cerebrovascular auto regulatory mechanisms have usually improved ( 22 ), and so our first interventional angiographic follow-up was planned to assess the degree of stenosis. In case the degree of stenosis is more than 70%, a balloon of an appropriate sized balloon was selected for angioplasty. In our series, the stent self-expansion criterion was found to treat successfully ICA stenosis in 19 patients out of 34 without post stenting angioplasty at any point in a -2 -year follow- up. But it was not found to be statistically significant. The remaining 15 patients required delayed angioplasty. Delayed stent expansion have been described in body and cardiac interventions for up to 9 months following the procedure ( 20 , 23 , 24 ). Using this concept in carotid artery stenosis, stenting has been successfully reported in 21 cases even without showing angioplasty ( 18 ). This study categorized the outcome of stent self-expansion into four groups. They employed these groups to have large immediate expansion with progressively continuing delayed expansion in 5 patients, small immediate expansion with rapid delayed expansion in 2 patients, balanced expansion with the total good residual stenosis in 12 patients, and unsuccessful expansion in 1 patient. They reported that three different stents were employed without perceived difference between them in the restoration of carotid artery recanalization. Single stent delayed occlusion after 18 months was also observed in calcified lesions. Stent self-expansion followed by neck x-ray, US Doppler and conventional angiography at times of intervals ( 18 ). Our aim was only to follow up the stenosis by conventional angiogram at 1 month, 1 year, 2year, and whenever it clinically warranted All the stents were successfully implanted in our investigation and we had no clinical evidence of ischemia. Silent strokes may not be excluded because we only employed the clinical picture. For failure of deployment of one stent in 21 patients, the authors had carotid artery stenting trial without intentional post stenting angioplasty. They had to use balloon angioplasty pre stenting to bypass the lesion, but the patient unfortunately developed a stroke ( 18 ). One of the patients experienced stent thrombosis upon discontinuation of the antiplatelet medication to prepare for a repeat colonoscopy procedure. In staged angioplasty procedure, it was reported that some carotid plaques were ulcerated with a frequency of silent embolic and thrombotic events on MRI after the first stage of angioplasty ( 17 ). A study also found that the frequency of thromboembolic complications was the same in the staged technique as in the routine method ( 7 ). Yoshimura, and colleagues performed Two-stage angioplasty in nine patients with no clinical or radiological evidence of HPS postoperatively on Single photon emission computed tomography (SPECT). However, they experienced (hyper perfusion phenomenon) HPP in five out of the nine patients (56%) immediately after stenting in the control CAS group. also, one patient (11%) developed status epileptics in the same group ( 17 ). The same was observed by Mo, and colleagues They had retrospectively analyzed 41 patients and concluded that staged angioplasty was effective in avoiding HPS in 40 patient and three patient developed the HP phenomenon during an examination by transcranial Doppler (TCD) after the second stage angioplasty( 7 ). We did not show any patient with a clinical presentation of HPS in our study. However, we only relied on the clinical presentation of HPS since we did not use any imaging modality to search for the HPP. Application of the stent without the employment of immediate angioplasty or balloon angioplasty in a staged stenting procedure allow gradual re-establishment of blood supply to the cerebral circulation. This is not possible by carotid endarterectomy to prevent HPS. Balloon angioplasty alone cannot prevent carotid restenosis. The stent must be placed to avoid this drawback. This procedure involves the patient having two cycles of intervention that can be costly in low resource-communities ( 7 ). Also, the use of a large sized balloon in angioplasty may cause vessel wall dissection and the ensuing need for emergency stenting rendering it one-stage procedure and depriving the advantage of staged procedure in maximizing the HPS. ( 17 , 7 ). In Comparing staged stenting with the conventional procedure, the authors concluded that the staged procedure was superior to the conventional procedure in preventing both hyper perfusion syndrome and hyper perfusion phenomenon. But the difference was not statistically significant in decreasing the incidence of hyper perfusion syndrome ( 7 ). Apart from the retrospective nature and small number of samples, the inclusion criteria for the population were only based on the clinical and radiological data. Cerebral perfusion studies and cerebrovascular reactivity were not utilized to ascertain whether these patients were actually hypo perfused or not. Moreover, the hyper perfusion phenomenon was not adequately assessed for the same reason. Conclusion Self-expansion criteria of carotid stent can be used to restore the perfusion to the hypo perfused brain gradually as a protective measure against the hyper perfusion syndrome. Pre interventional cerebrovascular reactivity can be used to select the patient appropriately for this procedure. Tables Abbreviations Carotid artery stenting (CAS) Carotid endarterectomy (CEA) Cerebral hyperperfusion syndrome (CHS) Hyperperfusion-induced cerebral hemorrhage (HICH) Activated coagulation time (ACT) Common carotid artery (CCA) Intensive care unit (ICU) North American Symptomatic Carotid Endarterectomy Trial (NASCET) Internal carotid artery (ICA) Hyperperfusion phenomenon (HPP) Cerebral blood flow (CBF) Declarations Ethics approval, consent to participate, consent for publication: The medical ethical review board of faculty of medicine, Ain shams University approved the study - approval number 000017585, and signed informed consents were obtained from the patients and/or their relatives for the procedure. Consent for publication: Not applicable. Availability of data and material: The raw data of this study are available from the corresponding author on reasonable request. Competing interests: The authors declared that they did not any conflict of interest. Funding: There was no funding of the study. Figures : the used figures are original Acknowledgements: the authors thank the patients who subjected to the study. References Chen LH, Spagnolo-Allende A, Yang D, Qiao Y, Gutierrez J. Epidemiology, pathophysiology, and imaging of atherosclerotic intracranial disease. Stroke. 2024;55(2):311–23. Müller MD, Lyrer P, Brown MM, Bonati LHJCDSR. Carotid artery stenting versus endarterectomy for treatment of carotid artery stenosis. Cochrane Database of Systematic Reviews , 2020(2). Zupan M, Perovnik M, Oblak P, J., Frol S. Post-Carotid Artery Stenting Hyperperfusion Syndrome in a Hypotensive Patient: Case Report and Systematic Review of Literature. Life. 2024;14(11):1472. Zha X, Liu Q, Deng K, Lu X, Xu Y. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6506729","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":463854249,"identity":"8204477d-394a-4154-a600-3015733da74a","order_by":0,"name":"Mohammed Alaswad","email":"data:image/png;base64,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","orcid":"","institution":"Suez Canal University","correspondingAuthor":true,"prefix":"","firstName":"Mohammed","middleName":"","lastName":"Alaswad","suffix":""},{"id":463854250,"identity":"b4369649-65db-4618-bb0d-3baa86090859","order_by":1,"name":"2.\tMona Ali Eissa","email":"","orcid":"","institution":"Helwan University","correspondingAuthor":false,"prefix":"","firstName":"2.\tMona","middleName":"Ali","lastName":"Eissa","suffix":""},{"id":463854251,"identity":"37e9ef71-bd93-4902-8c4d-09fbe4f44eb8","order_by":2,"name":"3.\tAlia H.Mansour","email":"","orcid":"","institution":"Ain Shams University","correspondingAuthor":false,"prefix":"","firstName":"3.\tAlia","middleName":"","lastName":"H.Mansour","suffix":""},{"id":463854252,"identity":"896a7cfb-4cee-457f-86ae-4380fa40550f","order_by":3,"name":"4.\tMohamed Khaled Elewa","email":"","orcid":"","institution":"Ain Shams University","correspondingAuthor":false,"prefix":"","firstName":"4.\tMohamed","middleName":"Khaled","lastName":"Elewa","suffix":""}],"badges":[],"createdAt":"2025-04-22 18:38:05","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6506729/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6506729/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":83813148,"identity":"de7cbb93-f3cf-4d5b-843d-4a1a3230b6ba","added_by":"auto","created_at":"2025-06-03 07:18:47","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":292737,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003e(case1)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(A) Severe stenosis in the right ICA, (B) delayed filling of right cerebral circulation with cross filling to the left circulation. (C, D) lateral and anteroposterior view ICA showed 50% stenosis immediately post stenting. ( E,F) lateral and anteroposterior view ICA showed less than 30% stenosis one month follow up without use of angioplasty. (G) Rapid and good filling of both right and left cerebral circulation on follow up in comparison to B.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6506729/v1/1c1c6720009a81a869f09618.png"},{"id":83811304,"identity":"ef128d9d-ce7a-444f-a800-665ce0402b08","added_by":"auto","created_at":"2025-06-03 07:02:47","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":513893,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003e(case 2)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(A) Left ICA subtotal occlusion ,(B) 50 residual stenosis after stent deployment (C,D) 1 month follow up angiogram showed 70% stenosis which required second stage angioplasty,(E) 6 month follow up showed recanalized left ICA with less than 10% stenosis\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6506729/v1/fca51c690b1eeb7b97859465.png"},{"id":88974832,"identity":"5350c50d-306a-4c3d-8883-18edb96aef9b","added_by":"auto","created_at":"2025-08-13 10:08:49","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1552188,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6506729/v1/6bd5750c-e4d5-4e17-b56f-c770239feb2f.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Carotid artery stenting without post-stenting angioplasty in patients with high risk for reperfusion injury (technical modification)","fulltext":[{"header":"Background","content":"\u003cp\u003eCarotid artery stenosis is the etiology of 15\u0026ndash;20% of cerebrovascular ischemic strokes (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Endovascular carotid artery stenting (CAS) is currently an accepted treatment alternative to carotid endarterectomy (CEA) with comparable outcomes (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Cerebral hyperperfusion syndrome (CHS) remains a serious complication following extracranial carotid artery revascularization. CHS is characterized by a\u0026thinsp;\u0026gt;\u0026thinsp;100% increase in cerebral perfusion above baseline levels (\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e) with an incidence ranging from 0.5\u0026ndash;6.8% (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Clinical presentations vary from migraine-type headache, seizures, and focal deficits, while radiological presentation may vary from normal to brain edema, subarachnoid hemorrhage, and intracerebral hemorrhage. Of interest, hyperperfusion-induced cerebral hemorrhage (HICH) carries a 75% mortality (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). The pathophysiology of CHS is theorized to be a result of derangement of cerebral autoregulation mechanisms within hypoperfused brains. Risk factors proven for CHS are hypertension, \u0026gt;\u0026thinsp;90% carotid artery stenosis, unfavorable collaterals, contralateral carotid disease, and recent stroke (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). While strict blood pressure control is the only method that is proven to be preventive, there have been recent descriptions of staged CAS being beneficial in terms of stepwise revascularization of cerebral circulation (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). This retrograde investigation had an innovative technique of stenting only without the immediate use of post stenting angioplasty within a single setting. The follow up angiographic assessment determining whether second-stage angioplasty is indicated.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eFollowing ethical committee approval, informed consent was obtained from patients for publication of their data. We identified patients with high risk for CHS and underwent Carotid artery stenting without post-stenting angioplasty retrospectively from our medical records between 2016 and 2024. The inclusion criteria were one or more of the factors implicated in a high risk of hyperperfusion injury (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e), and these included: Age\u0026thinsp;\u0026ge;\u0026thinsp;70 years, Diabetes mellitus, Chronic hypertension, chronic subtotal occlusions, Contralateral stenosis or occlusion, Extensive leukoaraiosis (Fazekas 3) (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e),recent stroke ,reperfusion within 2 weeks of the acute stroke, and Moderate to severe stroke. All patients received aspirin (325 mg/day) and clopidogrel (75 mg twice daily) for 7 days prior to the elective procedure (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). Antihypertensive medication was discontinued the night before. Conscious sedation was given to patients, and they were positioned in the supine position with bilateral groin area draping. Trans-femoral arterial diagnostic cerebral angiography was performed to evaluate the carotid lesion, vascular anatomy, and tandem lesions. Then a 5 French femoral sheath was exchanged for an 8 French 90 cm sheath for stability. Systemic heparinization was achieved with intravenous heparin (50\u0026ndash;70 units/kg), as confirmed by activated coagulation time (ACT) of 250\u0026ndash;350 seconds.\u003c/p\u003e \u003cp\u003eAfter that, the guiding catheter was advanced to the distal half of the common carotid artery (CCA) followed by a micro wire (0.014 inch) across the lesion for distal access.\u003c/p\u003e \u003cp\u003eThe critical stenosis were pre-dilated with an undersized balloon angioplasty so that the distal embolic protection device may be delivered through. Atropine IV (0.75) was utilized as prophylactic against bradycardia. Then distal embolic protection device was implanted in the distal cervical internal carotid artery.\u003c/p\u003e \u003cp\u003eUsing the road roadmap guidance, slowly released self-expandable stent with no post-stenting angioplasty. The distal embolic protection device was removed and inspected for trapped emboli. Finally, last angiographic run was performed to exclude stent thrombosis or distal cerebrovascular strokes. The femoral sheath was removed 8 hours later in the intensive care unit (ICU). All patients were closely monitored in the ICU for 48 hours for cerebrovascular and cardiovascular events. At discharge, patients resumed their usual medications, with the addition of 90 days of clopidogrel and lifelong aspirin therapy.\u003c/p\u003e \u003cp\u003eOutpatient follow-up included clinical monitoring for symptoms and signs of hypo-perfusion or hyper-perfusion. Radiological follow-up was done initially with conventional angiography to determine residual stenosis according to NASCET criteria. Second-stage angioplasty was indicated if stenosis exceeded 50%. Subsequent follow-up, for at least 2 years, included both clinical and radiological assessment with carotid duplex ultrasound. Data were statistical analyzed and Categorical data were presented as numbers and percentages. Chi-square test Used to test the significance between the different stages. For continuous data, they were tested for normality by Shapiro-Wilk test. Quantitative data were shown as range (minimum and maximum), mean, standard deviation and median. Pearson correlation to compare between more than two time periods or phases. Significance of the results obtained was assessed at the 5% level.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThirty four (34) patients form our study population is under normal distribution. While Males (25 patients) capture 73.53% sample size, female gender (9 patients) participated by 26.47%. Ages were of 49\u0026ndash;83 years and Mean was of 65.06\u0026thinsp;\u0026plusmn;\u0026thinsp;8.42 for standard deviation.\u003c/p\u003e\n\u003cp\u003eClinical risk factors of patients for hyper reperfusion syndrome was shown in table (1, 2). Hypertension, hypercholesterolemia and diabetes mellitus were the most prevalent comorbidities and contributed by 76.47%, 67.65%, and 61.76% respectively. Earlier stroke patients were categorized based on national institute health (NIH) as minor stroke NIH (\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e) (26.47%), and moderate stroke NIH (\u003cspan class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e15\u003c/span\u003e) (50%). none of our patients had Sever stroke. Transient ischemic attacks and amauraosis were observed in 20.59%, and 2.94% respectively. Our study population demonstrated sever ICA stenosis (stenosis more than 70%) in all the participants. Subtotal occlusion were found in 15 cases (38.24%) of them (hair line residual lumen and delayed intracranial ICA distal contrast filling). Two major causes were seen to produce the stenosis: atherosclerotic in 31 cases (91.18%) and dissection in 3 patients (8.82%). Atherosclerotic lesion was indicated by plaque calcification and ulceration in 9 patients (26.47%) and 5 patients (14.71%) respectively. Other radiological risk factors manifested in (Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e).Although pre-stenting angioplasty was done in all. In 14 of 34 cases (41.18%) protective filters were used with high risk of thromboembolic complications. Less than 30% residual stenosis was left in 10 cases (29.41%) after stent deployment without post angioplasty. Permissive residual stenosis of 30\u0026ndash;50% was allowed to avoid the risk of reperfusion injury in the remaining 24 cases (70.59%). (Table \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e)\u003c/p\u003e\n\u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003ecomorbidities risk factors\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eParameter\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eFrequency\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e% of Cases\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAge\u0026thinsp;\u0026gt;\u0026thinsp;80 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.82%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHTN\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e76.47%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ehypercholesterolemia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e67.65%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e61.76%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCAD/PVD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e50%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003esmoking\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e29.41%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCRD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14.71%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ecardiomyopathy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.82%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.88%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCLD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.88%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\"\u003eHTN (hypertension), DM (diabetes mellitus), CAD (coronary artery disease), PVD (peripheral vascular disease), CRD (chronic kidney diseases), AF (atrial fibrillation), CLD (chronic lung diseases).\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n\u003c/table\u003e\n\u003ctable id=\"Tab2\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eHistory of previous hypo perfusion manifestation (old ischemic events) more than 2 weeks before intervention\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eParameter\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eFrequency\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePercentage\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eModerate stroke NIH (\u003cspan class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e15\u003c/span\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e50%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eminor stroke NIH (\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e26.47%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTIA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e20.59%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eamaurosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.94%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003esevere stroke\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\"\u003eNIH (neurological institute of health scale for stroke evaluation), TIA (transient ischemic attack)\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003ctable id=\"Tab3\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eRadiological risk factors for reperfusion injury\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eRadiological findings\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eFrequency\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e% of Cases\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ehigh grade stenosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e100%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAtherosclerosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e91.18%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003esubtotal occlusion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e38.24%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eplaque calcification\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e26.47%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eextensive leukoaryosis (Fazekas 3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e20.59%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003econtralateral stenosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e17.65%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eplaque ulceration\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14.71%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003econtralateral occlusion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.82%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ecarotid dissection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.82%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDistal Tandem lesion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.82%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003emicrobleds\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.88%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003ctable id=\"Tab4\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eprocedural specification\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eParameter\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003efrequency\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePrestenting angioplasty\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e34 case (100%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUsing filter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14 out 34 cases (41.18%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eResidual stenosis\u003c/p\u003e\n \u003cp\u003e\u0026gt;30% AND\u0026thinsp;\u0026lt;\u0026thinsp;50%\u003c/p\u003e\n \u003cp\u003eLess than 30%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n \u003cp\u003e24 cases (70.59%)\u003c/p\u003e\n \u003cp\u003e10 cases (29.41%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eNo complication was seen during the procedure or at the immediate and remote follow up in a 2 -year- duration. Fifteen cases (44.12%) had a second stage angioplasty after a month. the stenting alone effectively treated the stenosis to below 30% in 19 patients (55.88%) significantly 13 patients (38.24%) were from the permissive stenosis group. But that was not statistically significant (Chi2\u0026thinsp;=\u0026thinsp;0.1, p\u0026thinsp;=\u0026thinsp;0.755) Table \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e. The Mean MRS\u0026thinsp;\u0026plusmn;\u0026thinsp;Std. before intervention was (1.71\u0026thinsp;\u0026plusmn;\u0026thinsp;1.22) while in follow- up was (1.35\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2). Their relationship at the last follow up was statistically significant, r (32)\u0026thinsp;=\u0026thinsp;0.88, p\u0026thinsp;=\u0026thinsp;\u0026lt;\u0026thinsp;.001.\u0026nbsp;\u003c/p\u003e\n\u003ctable id=\"Tab5\" border=\"1\" class=\"fr-table-selection-hover\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eNeed for second stage balloon angioplasty\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\" colspan=\"4\"\u003e\n \u003cp\u003eSecond stage balloon angioplasty during follow up\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eyes\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eno\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eTotal\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003en\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003en\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003en\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eresidual stenosis\u0026thinsp;\u0026gt;\u0026thinsp;30% AND\u0026thinsp;\u0026lt;\u0026thinsp;50%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e11\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e32.35%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e13\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e38.24%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e24\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e70.59%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eResidual stenosis\u0026thinsp;\u0026lt;\u0026thinsp;30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u003cstrong\u003e4\u003c/strong\u003e\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e11.76%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e6\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e17.65%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e10\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e29.41%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e15\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e44.12%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e19\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e55.88%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e34\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e100%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCases\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCase 1\u003c/p\u003e\n\u003cp\u003e69 year old male presented with history of recurrent transient ischemic attacks, cerebral angiogram showed right ICA high grade stenosis and left internal carotid artery (ICA) occlusion. He was treated with right translunar CAS without angioplasty. Residual after post stent deployment was 50%. Patient was discharged on dual antiplatelet. On follow up after one month, cerebral angiogram showed improvement in the stenosis to be less than 30% and hence no need for second stage angioplasty (Fig. 1).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCase 2\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e71 years old male history of left water shed area infarctions in left cerebral hemisphere. His cerebral angiography was demonstrating left ICA subtotal stenosis, after stent deployment the residual stenosis was 50%. On follow up angiogram done after 1 month the stenosis was raised to be 70%. Hence balloon angioplasty was done and residual stenosis was below 10%. (Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e)\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eHyperperfusion phenomenon (HPP) is referred to as an elevation in cerebral blood flow by over 100% than the base line when measured by transcranial Doppler (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e) or over 120% asymmetry index in cerebral blood flow (CBF) in relation to the normal side on CT perfusion (CTP). Hyper-perfusion syndrome (HPS) is used to refer to the development of clinical symptoms due to these changes. Even though this condition was initially described in 1981 as clinical syndrome of migarine like, transient focal seizure, and intracerebral hemorrhage appearance after carotid endarterectomy (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e), various other clinical presentations have been described. This is a state of strict definition of hemispheric neurological defect or seizure to occur after cerebral revascularization. It is ipsilateral to the artery that has been revascularized, is independent of thromboembolism, and there is no sign of new infarction on diffusion weighted MRI scans. MRI or CT Perfusion scans would show hyperperfusion of the ipsilateral hemisphere (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). HPS is most often associated with greater than 90% internal carotid artery (ICA) stenosis. Other significant risk factors are severe Contralateral ICA stenosis, poor collateral Flow, hypertension, and recent stroke. The higher the risk Factors, the higher the incidence (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). HPS risk factors are determined using clinical and radiological criteria. We defined our inclusion criteria from clinical presentations of patients and demonstration of carotid stenosis greater than 90%, poor collaterals and contralateral ICA stenosis. We did not employ cerebral perfusion tests or challenge tests to identify which of the patients examined had impaired auto regulatory mechanisms since these are expensive and not readily available. Prevention and HPS management continue to be contentious with agreement being control of blood pressure (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). While we were successful in keeping our patients' systolic blood pressure 20% below their base-line, we could not verify or disprove whether this therapy had any effect on the hyper -perfusion phenomenon. This is because of the absence of transcranial Doppler and perfusion images during the immediate follow -up period. Certain authors have reported the staged carotid artery stenting procedure as another way to reduce the incidence of CHS. At the first stage, balloon angioplasty was performed followed by stenting after a month in a second stage (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). The Stenting-alone procedure was reported to overcome the embolic complication of carotid angioplasty as well as rectify the stenosis by virtue of the self-expanding character of the stent (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). This technique relies on observation of progressive dilation of an obstructive malignant biliary stricture by self-expanding stenting alone without angioplasty in the days after the procedure (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e).Nevertheless the authors of the initial report intended to reduce embolic complications. The population features in their study were not comparable with our patients with the exception of severe carotid stenosis. We initially pre stented in our experience, then stenting alone without initial angioplasty to allow the radial force of the stent to open up the blood supply slowly. On follow-up, when ICA stenosis by NACET criteria exceeded 70%, angioplasty was done. Even though stent carotid choice is based on factors such as trackability, scaffolding of atheromatous plaques and radial force to achieve maximal patency, we employ various types of self-expanding stents such as Acculink (Guidant, Santa Clara, California), Prot\u0026eacute;g\u0026eacute; (ev3, Plymouth, Minnesota), and carotid Wallstent (Boston Scientific, Natick, Massachusetts) based on their availability. Although the Prot\u0026eacute;g\u0026eacute; stent (ev3, Plymouth, Minnesota) was reported to have maximum radial force properties, its open cell structure must be employed with care in combination with distal protection devices to prevent distal emboli (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e). In very tight stenosis we crossed the lesion with steerable micro-wires of 0.010 and 0.014 diameters such as Synchro (Stryker Neurovascular) and The Traxcess (Microvention). We used pre stenting angioplasty in all the cases as crossing these lesions directly with stent delivery catheter was reported to have embolic complications or dissections (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDistal embolic devices were used in the setting of subtotal occlusion and plaque ulceration to prevent distal showering in 14 out of 34 cases 41 (18%). By one month the cerebrovascular auto regulatory mechanisms have usually improved (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e), and so our first interventional angiographic follow-up was planned to assess the degree of stenosis. In case the degree of stenosis is more than 70%, a balloon of an appropriate sized balloon was selected for angioplasty. In our series, the stent self-expansion criterion was found to treat successfully ICA stenosis in 19 patients out of 34 without post stenting angioplasty at any point in a -2 -year follow- up. But it was not found to be statistically significant. The remaining 15 patients required delayed angioplasty. Delayed stent expansion have been described in body and cardiac interventions for up to 9 months following the procedure (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). Using this concept in carotid artery stenosis, stenting has been successfully reported in 21 cases even without showing angioplasty (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). This study categorized the outcome of stent self-expansion into four groups. They employed these groups to have large immediate expansion with progressively continuing delayed expansion in 5 patients, small immediate expansion with rapid delayed expansion in 2 patients, balanced expansion with the total good residual stenosis in 12 patients, and unsuccessful expansion in 1 patient. They reported that three different stents were employed without perceived difference between them in the restoration of carotid artery recanalization. Single stent delayed occlusion after 18 months was also observed in calcified lesions. Stent self-expansion followed by neck x-ray, US Doppler and conventional angiography at times of intervals (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). Our aim was only to follow up the stenosis by conventional angiogram at 1 month, 1 year, 2year, and whenever it clinically warranted\u003c/p\u003e \u003cp\u003eAll the stents were successfully implanted in our investigation and we had no clinical evidence of ischemia. Silent strokes may not be excluded because we only employed the clinical picture. For failure of deployment of one stent in 21 patients, the authors had carotid artery stenting trial without intentional post stenting angioplasty. They had to use balloon angioplasty pre stenting to bypass the lesion, but the patient unfortunately developed a stroke (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). One of the patients experienced stent thrombosis upon discontinuation of the antiplatelet medication to prepare for a repeat colonoscopy procedure. In staged angioplasty procedure, it was reported that some carotid plaques were ulcerated with a frequency of silent embolic and thrombotic events on MRI after the first stage of angioplasty (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). A study also found that the frequency of thromboembolic complications was the same in the staged technique as in the routine method (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Yoshimura, and colleagues performed Two-stage angioplasty in nine patients with no clinical or radiological evidence of HPS postoperatively on Single photon emission computed tomography (SPECT). However, they experienced (hyper perfusion phenomenon) HPP in five out of the nine patients (56%) immediately after stenting in the control CAS group. also, one patient (11%) developed status epileptics in the same group (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). The same was observed by Mo, and colleagues They had retrospectively analyzed 41 patients and concluded that staged angioplasty was effective in avoiding HPS in 40 patient and three patient developed the HP phenomenon during an examination by transcranial Doppler (TCD) after the second stage angioplasty(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). We did not show any patient with a clinical presentation of HPS in our study. However, we only relied on the clinical presentation of HPS since we did not use any imaging modality to search for the HPP. Application of the stent without the employment of immediate angioplasty or balloon angioplasty in a staged stenting procedure allow gradual re-establishment of blood supply to the cerebral circulation. This is not possible by carotid endarterectomy to prevent HPS. Balloon angioplasty alone cannot prevent carotid restenosis. The stent must be placed to avoid this drawback. This procedure involves the patient having two cycles of intervention that can be costly in low resource-communities (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Also, the use of a large sized balloon in angioplasty may cause vessel wall dissection and the ensuing need for emergency stenting rendering it one-stage procedure and depriving the advantage of staged procedure in maximizing the HPS. (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). In Comparing staged stenting with the conventional procedure, the authors concluded that the staged procedure was superior to the conventional procedure in preventing both hyper perfusion syndrome and hyper perfusion phenomenon. But the difference was not statistically significant in decreasing the incidence of hyper perfusion syndrome (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Apart from the retrospective nature and small number of samples, the inclusion criteria for the population were only based on the clinical and radiological data. Cerebral perfusion studies and cerebrovascular reactivity were not utilized to ascertain whether these patients were actually hypo perfused or not. Moreover, the hyper perfusion phenomenon was not adequately assessed for the same reason.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eSelf-expansion criteria of carotid stent can be used to restore the perfusion to the hypo perfused brain gradually as a protective measure against the hyper perfusion syndrome. Pre interventional cerebrovascular reactivity can be used to select the patient appropriately for this procedure.\u003c/p\u003e \u003cp\u003eTables\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eCarotid artery stenting (CAS)\u003c/p\u003e\n\u003cp\u003eCarotid endarterectomy (CEA)\u003c/p\u003e\n\u003cp\u003eCerebral hyperperfusion syndrome (CHS)\u003c/p\u003e\n\u003cp\u003eHyperperfusion-induced cerebral hemorrhage (HICH)\u003c/p\u003e\n\u003cp\u003eActivated coagulation time (ACT)\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCommon carotid artery (CCA)\u003c/p\u003e\n\u003cp\u003eIntensive care unit (ICU)\u003c/p\u003e\n\u003cp\u003eNorth American Symptomatic Carotid Endarterectomy Trial\u0026nbsp;(NASCET)\u003c/p\u003e\n\u003cp\u003eInternal carotid artery (ICA)\u003c/p\u003e\n\u003cp\u003eHyperperfusion phenomenon (HPP)\u003c/p\u003e\n\u003cp\u003eCerebral blood flow (CBF)\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval, consent to participate, consent for publication:\u0026nbsp;\u003c/strong\u003eThe medical ethical review board of faculty of medicine, Ain shams University approved the study - approval number 000017585, and signed informed consents were obtained from the patients and/or their relatives for the procedure.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and material:\u0026nbsp;\u003c/strong\u003eThe raw data of this study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u0026nbsp;\u003c/strong\u003eThe authors declared that they did not any conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u0026nbsp;\u003c/strong\u003eThere was no funding of the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFigures\u003c/strong\u003e: the used figures are original\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u0026nbsp;\u003c/strong\u003ethe authors thank the patients who subjected to the study.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eChen LH, Spagnolo-Allende A, Yang D, Qiao Y, Gutierrez J. Epidemiology, pathophysiology, and imaging of atherosclerotic intracranial disease. Stroke. 2024;55(2):311\u0026ndash;23.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM\u0026uuml;ller MD, Lyrer P, Brown MM, Bonati LHJCDSR. Carotid artery stenting versus endarterectomy for treatment of carotid artery stenosis. \u003cem\u003eCochrane Database of Systematic Reviews\u003c/em\u003e, 2020(2).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZupan M, Perovnik M, Oblak P, J., Frol S. Post-Carotid Artery Stenting Hyperperfusion Syndrome in a Hypotensive Patient: Case Report and Systematic Review of Literature. Life. 2024;14(11):1472.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZha X, Liu Q, Deng K, Lu X, Xu Y. Prediction of intracranial hemorrhage after internal carotid artery stenting in patients with symptomatic severe carotid stenosis by computed tomography perfusion. Quant Imaging Med Surg. 2023;13(6):3927.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao B, Jiang X, Wang P, Zhao Z, Mang J, Xu Z. Staged angioplasty: A sensible approach to prevent hyperperfusion syndrome after carotid artery stenting? A meta-analysis. Interventional Neuroradiol. 2022;28(1):115\u0026ndash;23.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYan L, Song J, Yu Y, Hou Z, Fu W, Cui R, et al. Predictors of hyperperfusion syndrome after stent implantation in symptomatic intracranial atherosclerotic stenosis. Quant Imaging Med Surg. 2022;13(2):1048.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMo D, Jia B, Shi H, Sun Y, Liu Q, Fan C et al. Staged angioplasty versus regular carotid artery stenting in patients with carotid artery stenosis at high risk of hyperperfusion: a randomised clinical trial. Stroke Vascular Neurol 2021; 6(1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXu S, Wu P, Zhang T, Ji Z, Wang C, Shi HJWN. Prevalence and clinical predictors of intracranial hemorrhage following carotid artery stenting for symptomatic severe carotid stenosis. World Neurosurg. 2021;155:e353\u0026ndash;61.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCarnevale M, Koleilat I, Friedmann P, Aldailami HJJVS. Risk factors for cerebral hyperperfusion syndrome in patients undergoing transcarotid artery revascularization in the vascular quality initiative. J Vasc Surg. 2021;74(3):e146\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHsu AC, Williams B, Ding L, Weaver FA, Han SM, Magee GAJAVS. Risk Factors for Cerebral Hyperperfusion Syndrome following Carotid Revascularization. Ann Vasc Surg. 2023;97:89\u0026ndash;96.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAndere A, Jindal G, Molino J, Collins S, Merck D, Burton T, et al. Volumetric white matter hyperintensity ranges correspond to Fazekas scores on brain MRI. J Stroke Cerebrovasc Dis. 2022;31(4):106333.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWhite CJ, Brott TG, Gray WA, Heck D, Jovin T, Lyden SP, et al. Carotid artery stenting: JACC state-of-the-art review. Am J Neuroradiol. 2022;80(2):155\u0026ndash;70.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHashimoto K, Yoshioka H, Kanemaru K, Senbokuya N, Kinouchi HJWN. A Novel Staged Revascularization Strategy for Bilateral Severe Internal Carotid Artery Stenosis at High Risk for Hyperperfusion Syndrome. World Neurosurg. 2023;177:e294\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVuurberg NE, Post IC, Keller BPJ, Schaafsma A, Vos, CGJAovs. A systematic review and meta-analysis on perioperative cerebral and hemodynamic monitoring methods during carotid endarterectomy. Ann Vasc Surg. 2023;88:385\u0026ndash;409.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDiana F, Frauenfelder G, Botto A, Saponiero R, Romano DGJIN. Cerebral hyperperfusion syndrome after intracranial stenting: Case report and systematic review. Interventional Neuroradiol. 2021;27(6):843\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOgasawara K, Yukawa H, Kobayashi M, Mikami C, Konno H, Terasaki K, et al. Prediction and monitoring of cerebral hyperperfusion after carotid endarterectomy by using single-photon emission computerized tomography scanning. J Neurosurg. 2003;99(3):504\u0026ndash;10.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYoshimura S, Kitajima H, Enomoto Y, Yamada K, Iwama TJON. Staged angioplasty for carotid artery stenosis to prevent postoperative hyperperfusion. Operative Neurosurg. 2009;64(3):ons122\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLownie SP, Pelz DM, Lee DH, Men S, Gulka I, Kalapos PJA. Efficacy of treatment of severe carotid bifurcation stenosis by using self-expanding stents without deliberate use of angioplasty balloons. 2005;26(5):1241\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKiwan R, Jukes A, Mayich M, Boulton M, Sharma M, Pelz D, et al. A protocol for carotid artery stenting in COVID times. A single Canadian centre experience. Can J Neurol Sci. 2022;49(3):361\u0026ndash;3.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMoutzoukis M, Argyriou K, Kapsoritakis A, Christodoulou DJWJGE. Endoscopic luminal stenting: Current applications and future perspectives. World J Gastrointest Endoscopy. 2023;15(4):195.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eErkol A, Dalgı\u0026ccedil; Y, Yıldırım S, Turan BJCN, Neurosurgery. Incidence and predictors of prolonged hemodynamic depression after carotid artery stenting: Yet another benefit of statins? Clin Neurol Neurosurg. 2021;207:106786.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAmemiya S, Takao H, Watanabe Y, Takei N, Ueyama T, Kato S, et al. Reliability and sensitivity to longitudinal CBF changes in steno-occlusive diseases: ASL versus 123I‐IMP‐SPECT. J Magn Reson Imaging. 2022;55(6):1723\u0026ndash;32.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIstanbullu OB, Akdogan GJCE, Technology. Influences of Stent design on in-stent restenosis and major cardiac outcomes: a scoping review and meta-analysis. Cardiovasc Eng Technol. 2022;13(1):147\u0026ndash;69.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNg P, Maehara A, Kirtane AJ, McEntegart M, Jaffer FA, Doshi D, et al. Management of Coronary Stent Underexpansion. J Am Coll Cardiol. 2025;85(6):625\u0026ndash;44.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-6506729/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6506729/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCerebral Hyper perfusion Syndrome (CHS) is an ominous complication that can follow extracranial carotid artery revascularization. The most dangerous consequence of CHS is Hyperperfusion-Induced Cerebral Hemorrhage (HICH), which boasts a staggering mortality of 75%. The pathophysiology of HICH is thought to be disruption of cerebral autoregulation mechanisms in hypo-perfused brains, leading to a disastrous cerebral blood flow rise. Several risk factors have been reported for HICH, such as: Hypertension, Severe carotid artery stenosis (\u0026gt;90%), Poor collaterals, Contralateral carotid disease, and recent cerebrovascular events. Even though strict blood pressure control is the only established method of prevention of CHS, new evidence suggests that staged carotid artery stenting (CAS) can also offer additional preventive benefits by facilitating gradual reconstitution of cerebral blood flow. In this retrospective study, we examined the efficacy of a staged CAS approach. We performed stent alone without performing an angioplasty in the initial session, making use of the stent's radial force to gradually restore blood flow. Follow-up angiographic evaluation was used to identify candidates for a second-stage angioplasty.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eRetrospective analysis was done in high-risk patients with extracranial carotid artery stenosis who underwent carotid artery stenting (CAS) without post-stenting angioplasty. The study evaluated the effectiveness of stent self-expansion in re-establishing cerebral perfusion and the clinical evidence of hyperperfusion or hypoperfusion. Follow-up cerebral angiography detected those patients requiring additional treatment with angioplasty. After deployment of stent without immediate post-angioplasty, a residual stenosis of \u0026lt;30% was seen in 10 cases (29.41%). Permissive residual stenosis of 30% to 50% was allowed to avoid the risk of reperfusion injury in the other 24 cases (70.59%). After 1 month follow-up, 44.12% (15/34) of cases required second-stage angioplasty and 55.88% (19/34) of cases were successfully treated with stenting alone, with a decrease in stenosis to \u0026lt;30%. Interestingly, 13/19 (68.4%) of them belonged to the permissive stenosis group. That was, however, statistically non-significant (Chi2 =0.1, p=0.755).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs a safeguard against the hyperperfusion syndrome, the carotid stent's self-expanation criteria can be used to progressively restore blood flow to the hypoperfused brain.\u003c/p\u003e","manuscriptTitle":"Carotid artery stenting without post-stenting angioplasty in patients with high risk for reperfusion injury (technical modification)","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-03 07:02:42","doi":"10.21203/rs.3.rs-6506729/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"162cf645-fe57-4ca3-8532-bcf3fccf2271","owner":[],"postedDate":"June 3rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-08-13T10:08:21+00:00","versionOfRecord":[],"versionCreatedAt":"2025-06-03 07:02:42","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6506729","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6506729","identity":"rs-6506729","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}