Hyperperfusion Syndrome Research Articles

De Novo Cerebral Microbleeds and Cognitive Decline in Cerebral Hyperperfusion After Direct Revascularization for Adult Moyamoya Disease

ObjectivesAdult patients with moyamoya disease (MMD) occasionally develop cognitive decline due to cerebral hyperperfusion following direct revascularization surgery. However, how the hyperperfusion phenomenon contributes to declines in cognitive function remains unclear. The present supplementary analysis of a prospective study aimed to determine whether cerebral hyperperfusion following direct revascularization surgery for adult MMD with ischemic presentation and misery perfusion leads to development of de novo cerebral microbleeds (CMBs) and whether postoperative cognitive decline is related to these CMBs. Materials and MethodsIn total, 32 patients who underwent direct revascularization surgery also underwent T2*-weighted magnetic resonance imaging (T2*WI) and neuropsychological testing before and 2 months after surgery. Development of cerebral hyperperfusion and hyperperfusion syndrome following surgery was defined based on brain perfusion single-photon emission computed tomography (SPECT) findings and clinical symptoms. ResultsCerebral hyperperfusion on brain perfusion SPECT (95% confidence interval [CI], 1.1–10.8; p = 0.0175) or cerebral hyperperfusion syndrome (95%CI, 1.3–15.3; p = 0.0029) was significantly associated with postoperatively increased CMBs on T2*WI. Postoperatively increased CMBs were significantly associated with postoperative cognitive decline (95%CI, 1.8–20.4, p = 0.0041). For patients with cerebral hyperperfusion on brain perfusion SPECT, the incidence of postoperative cognitive decline was significantly greater in patients with than in those without postoperatively increased CMBs (p = 0.0294). ConclusionsCerebral hyperperfusion following direct revascularization surgery for adult MMD with ischemic presentation and misery perfusion contributes to the development of de novo CMBs and postoperative cognitive decline is related to these CMBs.

The periprocedural and 30-day outcomes of carotid stenting in patients with carotid artery near-occlusion

The safety of endovascular revascularization in patients with carotid artery near occlusion (CANO) is unknown. We aimed to evaluate the peri-procedural risk in CANO patients receiving carotid artery stenting (CAS). A prospective data base with retrospective review was performed to identify patients who underwent CAS with CANO from July 2006 to July 2020, and had at least 1-month clinical follow-up data. The primary endpoints were stroke, hyperperfusion syndrome, and death within 30 days after CAS. A total of 198 patients with carotid artery stenosis were enrolled including 92 patients with CANO and 106 age and sex-matched patients with 70–99% conventional carotid stenosis. Full distal carotid collapse was found in 45 CANO patients (45/92, 49%). The technical success rate was 100%. The CANO patients had significantly longer lesion lengths compared with those of the non-CANO group. The incidence of hyperperfusion syndrome was comparable (CANO: 2.2%, non-CANO: 0.9%, P = 0.598). The risks of ischemic stroke and death within 30 days were 1.1% and 0% in the CANO group; and 1.9% and 0.9%, in the non-CANO group, respectively, without statistical difference. In conclusion, CAS is safe for patients with CANO, with a similar low 30-day peri-procedural event rate comparable to those of non-CANO.

Decoding the Onset of Intraoperative Normal Pressure Perfusion Breakthrough with Near-Infrared Spectroscopy and Jugular Venous Oxygen Saturation Catheter in a Case of Arteriovenous Malformation Surgery

AbstractMultimodal monitoring can be a useful tool to design an appropriate anesthesia technique in the intraoperative period during the surgical excision of an intracerebral arteriovenous malformation (AVM). Intraoperatively, hyperperfusion syndrome can be attributed to causes like insufficient blood pressure control, occlusion of venous drainage before complete resection of arterial feeders, or inadequate hemostatic control of distended capillaries receiving arterial flow. We would like to highlight the potential role of near-infrared spectroscopy and jugular venous oxygen saturation catheter in detection of intraoperative normal perfusion pressure breakthrough and take necessary measures to prevent further insult with the help of this case report.

Multicenter study: outcomes of carotid endarterectomy depending on configuration of circle of Willis

BACKGROUND: The circle of Willis (CW) is an important network of collaterals that provide compensatory redistribution of hemodynamic load. Several studies showed that the CW is open in approximately 50%90% of cases, and the number of missing segments correlates with low brain tolerance to ischemia in internal carotid artery (ICA) compression. Currently, studies dedicated to the relationship of different configurations of CW with the risk of ischemic brain damage.
 AIM: The analyze the immediate results of eversion carotid endarterectomy (CEA) in patients with different configurations of the structure of the CW.
 MATERIALS AND METHODS: We included 641 patients with hemodynamically significant stenosis of the internal carotid arteries (ICA) in a study period from 2010 to 2020. All patients underwent multispiral computed tomography with angiography of the extracranial and CW arteries. Based on the structural variants of the CW, six groups of patients were studied: group 1 (64.9%, n = 416) closed posterior part (CPP) with the existence of posterior communicative artery (PCA) and P1 segment of the posterior cerebral artery (PCerA); group 2 (27%, n = 173) an intermediate structure of the posterior part (IPP) with hypoplasia of the PCA or PCerA; group 3 (8.1%, n = 52) open posterior part (OPP) with the absence of PCA or PCerA; group 4 (85.95%, n = 551) closed anterior part (CAP) with the presence of the anterior communicating artery (ACA) and A1 segment of the anterior cerebral artery (ACerA); group 5 (7.95%, n = 51) an intermediate structure of the anterior part (IAP) with hypoplasia of ACA or ACerA; group 6 (6.1%, n = 39) open anterior part (OAP) with the absence of ACA or ACerA. To assess the compensatory potentials of the brain, all patients underwent measurement of the retrograde pressure in the ICA and intraoperative cerebral oximetry.
 RESULTS: In the postoperative period, 1 death was recorded in group 4 (CAP) due to a hemorrhagic transformation in the zone of ischemic stroke, on the background development of hyperperfusion syndrome. The largest number of ischemic strokes of the cardioembolic subtype was diagnosed in the ACerA territory in the presence of an unstable atherosclerotic plaque: group 1 (CPP) 0%; group 2 (IPP) 0%; group 3 (OPP) 0.24%, n = 1; group 4 (CAP) 0.18%, n = 1; group 5 (IAP) 1.96%, n = 1; group 6 (OAP) 5.1%, n = 2; p 0.9999. The probable cause was embolization against the background increase in the arterial pressure before ICA clamping. In turn, the majority of ischemic strokes of the hemodynamic subtype developed in the territory of PCerA: group 1 (CPP) 0%; group 2 (IPP) 1.73%, n = 3; group 3 (OPP) 3.8%, n = 2; group 4 (CAP) 0.18%, n = 1; group 5 (IAP) 0%; group 6 (OAP) 2.56%, n = 1; p 0.9999. This pattern coincided with the largest number of patients with CW of the IPP and OPP types among all open variants of the structure.
 CONCLUSION: Parameters of retrograde pressure in the ICA and intraoperative cerebral oximetry do not always demonstrate the need for a temporary shunt (TS). Due to the opened structure of CW, the redistribution of blood flow occurs with the formation of zones of hypo- and hyperperfusion, causing ischemic alterations in the brain matter. Thus, in order to maintain adequate cerebral hemodynamics, to mitigate the effect of hypo- and hyperperfusion, and reduce the risk of ischemic stroke, the open variant of the CW structure should be considered as an indication for a TS.

Neuroimaging of intracranial stenosis

Cerebral hyperperfusion syndrome is a potential complication after intracranial angioplasty or stenting and ASL imaging could be used to predict and diagnose hyperperfusion syndrome and contribute to reduce its complications, making it possible to better manage patients undergoing endovascular treatment.

Neuroimaging of intracranial stenosis

Cerebral hyperperfusion syndrome is a potential complication after intracranial angioplasty or stenting and ASLimaging could be used to predict and diagnose hyperperfusion syndrome and contribute to reduce its complications,making it possible to better manage patients undergoing endovascular treatment.

Intraoperative blood pressure lability carries a higher risk of headache after carotid endarterectomy

ObjectiveCerebral hyperperfusion syndrome (CHS) is a rare but potentially devastating complication after carotid endarterectomies (CEA). Its symptoms range from new-onset unilateral headache (HA) to intracranial hemorrhage (ICH). Risk factors for CHS in the literature to date have not yet yielded a consensus. This study examines intraoperative and postoperative blood pressure variations as potential risk factors for HA. MethodsA single-center retrospective review at a tertiary care center from January 2010 to November 2019 was performed. Inclusion criteria were all patients undergoing CEA for symptomatic or asymptomatic carotid disease. Patients with incomplete charts were excluded. Primary endpoints were new-onset unilateral HA or postoperative ICH. Data on intraoperative and postoperative mean arterial pressure (MAP), systolic blood pressure (SBP), the mode of endarterectomy, shunt placement, and contralateral carotid status were collected. ResultsThere were 735 patients who met the inclusion criteria: 430 patients underwent modified eversion CEA (59%) and 305 patients for patch angioplasty (42%). The incidence of HA was 19% (n = 142) in our total cohort. Of the 19% with HA, 1.5% (n = 11) demonstrated no relief with analgesics and strict blood pressure control; noncontrast head computed tomography scans were performed subsequently. One patient (0.1%) had an ipsilateral ICH. Univariate analysis demonstrated that greater intraoperative MAP peak had the highest risk for HA (odds ratio [OR], 1.014; 95% confidence interval [CI], 1.007-1.022; P = .0002), followed by intraoperative MAP variability (OR, 1.011; 95% CI,1.005-1.018; P ≤ .0008), and peak intraoperative SBP (OR, 1.01; 95% CI, 1.004-1.015; P = .0011). An unpaired Student t test identified change in intraoperative MAP (P < .005), change in the SBP (P < .005), and peak SBP (P < .001) were significantly associated with HA. Interestingly, there was no significant difference between postoperative MAP variability and HA (P = .1). The mode of endarterectomy showed no statistically significant difference in risk for developing HA (OR, 1.165; 95%; 95% CI, 0.801-1.694; P = .42). ConclusionsGreater intraoperative variability in blood pressures are significantly associated with a higher risk of HA. Adhering to stricter intraoperative blood pressure parameters and limiting blood pressure variability may be beneficial at decreasing the incidence of CHS and its complications.

Influence of Eversion Endarterectomy and Patch Reconstruction on Postoperative Blood Pressure After Carotid Surgery

Post carotid blood pressure fluctuation and hypertension (PEH) are associated with increased risk for adverse outcome; there is limited evidence on the impact of eversion endarterectomy (E-CEA) versus conventional endarterectomy with patch closure (C-CEA) on postoperative blood pressure course. In this retrospective observational study, 859 consecutive carotid endarterectomy procedures between 2004 and 2014 (C-CEA n=585 vs. E-CEA n=274), were evaluated. Pre- and postoperative blood pressure values were recorded from recovery room until third postoperative day and compared between both techniques; influences on the dichotomous target variable "at least one postoperative blood pressure peak", that is need for postoperative vasodilators, were analyzed by a logistic regression model. Influences on postoperative systolic blood pressure were evaluated by a linear mixed effects regression model. Preoperative baseline blood pressure was not different between both comparison groups. During postoperative course, significantly increased mean systolic blood pressure values in the E-CEA group from recovery room to second postoperative day (recovery room C-CEA: 129.2 mm Hg vs. E-CEA: 136.5 mm Hg; P < 0.001; first postoperative day C-CEA: 132.4 mm Hg vs. E-CEA: 139.3 mm Hg; P=0.0002; second postoperative day C-CEA: 138.6 mm Hg vs. E-CEA: 143.1 mm Hg; P=0.023) were observed. No hyperperfusion syndrome was detected as wells as no difference in postoperative complication rate. Frequency of antihypertensive interventions was also elevated in E-CEA group (C-CEA 22.1 % vs. E-CEA 31.8 %; P=0.003). E-CEA (OR 1.591, 95% CI [1.146; 2.202]; P=0.005) and presence of preoperatively elevated systolic readings (OR 1.015, 95%CI [1.006;1.024]; P < 0.001) was also associated with increased need for antihypertensive interventions. E-CEA was associated with significantly elevated postoperative blood pressure, compared to C-CEA. C-CEA was associated with postoperative blood pressure decrease; however, no difference as to neurologic and surgical complications was detected between both surgical techniques in clinical practice.

Risk Factors for Cerebral Hyperperfusion Syndrome in Patients Undergoing Transcarotid Artery Revascularization in the Vascular Quality Initiative

Cerebral hyperperfusion syndrome (CHS) is a well-described, rare, postoperative complication among patients undergoing carotid revascularization. Most of the literature on this topic have been from patients who have undergone carotid endarterectomy; the reported data are sparse regarding patients who have undergone carotid stenting. Novel approaches to carotid stenting include transcarotid artery revascularization (TCAR), in which flow in the carotid artery is reversed for cerebral protection from atheroembolism.

Isolated Intraventricular Hemorrhage after Carotid Artery Stenting

Cerebral intraventricular hemorrhage (IVH) is an extremely rare complication of carotid artery stenting (CAS). Fully dilated terminal arteries of a chronic, severely stenosed proximal artery could be ruptured by impaired autoregulation of cerebral blood flow. Hyperperfusion syndrome can occur even if there is no blood pressure fluctuation during the CAS. We report a case of an isolated IVH that occurred hours after CAS.

Transcranial Doppler to evaluate postreperfusion therapy following acute ischemic stroke: A literature review.

Cerebral vessel recanalization therapy, either intravenous thrombolysis or mechanical thrombectomy, is the main treatment that can significantly improve clinical outcomes after acute ischemic stroke. The degree of recanalization and cerebral reperfusion of the ischemic penumbra are dependent on cerebral hemodynamics. Currently, the main imaging modalities to assess reperfusion are MRI and CT perfusion. However, these imaging techniques cannot predict reperfusion-associated complications and are not readily available in many centers. It is also not feasible to repeat them frequently for sequential assessments, which is important because of the changing nature of cerebral hemodynamics following stroke. Transcranial Doppler sonography (TCD) is a valid, safe, and inexpensive technique that can assess recanalized vessels and reperfused tissue in real-time at the bedside. Post thrombectomy reocclusion, hyperperfusion syndrome, distal embolization, and remote infarction result in poor outcomes after mechanical or intravenous reperfusion therapy. Managing blood pressure following these endovascular treatments can also be a dilemma. TCD has an important role, with major clinical implications, in evaluating cerebral hemodynamics and collateral vessel status, guiding clinicians in making individualized decisions based on cerebral blood flow during acute stroke care. This review summarizes the most relevant literature on the role of TCD in evaluating patients after reperfusion therapy. We also discuss the importance of performing TCD in the first few hours following thrombolytic therapy in identifying hyperperfusion syndrome and embolic signals, predicting recurrent stroke, and detecting reocclusions, all of which may help improve patient prognosis. We recommend TCD during the hyperacute phase of stroke in comprehensive stroke centers.

Rapid popliteal artery release sensu A.N. Kazantsev in acute thrombosis in patients with COVID-19

Aim. To analyze the outcomes of popliteal thrombectomy using the standard release technique with vascular instruments and rapid release sensu A. N. Kazantsev in patients with acute popliteal artery thrombosis (PAT) and coronavirus disease 2019 (COVID-19).Material and methods. The present prospective single-center study for the period from April 1, 2020 to March 17, 2021 included 157 patients with acute PAT and COVID-19 at the Alexandrovskaya City Hospital. All patients were divided into 2 groups depending on the popliteal artery access: group 1 (n=88; 56%) — rapid release sensu A. N. Kazantsev; group 2 (n=69; 44%) — standard popliteal artery release using vascular instruments (vascular forceps and scissors) and tourniquets. Rapid popliteal artery release was distinguished by the fact that fasciotomy and hemostasis, the fatty tissue behind it and up to the artery was torn with two index fingers. First, the fingers were joined together at the lateral edges and inserted into the wound middle. Then the wound together with tissues was stretched with fingers to proximal and distal edges until the popliteal artery was visualized. Further, a Beckmann retractor was used to fix the torn fiber to the upper and lower wound walls. The tourniquets were not used.Results. Surgical access duration (group 1, 4,5±1,3 minutes; group 2, 11,41±0,9 minutes; p=0,005), as well as the total procedure duration (group 1, 47,5±2,8 minutes; group 2, 62,15±4,5 min; p=0,001) had the lowest values in the group of rapid popliteal artery release. Moreover, all intraoperative bleedings (n=11; 15,9%) was recorded in group 2 as a result of popliteal vein injuries and/or bleeding from popliteal artery. The retrombosis rate in the rapid release group was lower (group 1, 40,9%; group 2, 55,1%; p=0,03). On the first day after surgery, 18% of thrombosis developed in group 1, and 39% in group 2. The mortality rate was highest in the standard artery release group (group 1, 55,7%; group 2, 86,9%; p&lt;0,0001; OR, 0,18; 95% CI, 0,08-0,42). In all cases, the cause of death was systemic multiple organ failure due to severe pneumonia, pulmonary edema, and cytokine storm.Conclusion. The use of rapid popliteal artery release sensu A. N. Kazantsev significantly reduces the thrombectomy duration in the context of COVID-19. This effect is achieved due to a decrease in the incidence of intraoperative bleeding, no need to use tourniquets and vascular instruments. A decrease in the ischemia duration using novel release technique reduces the retrombosis rate, as well as deaths caused by systemic multiple organ failure against the background of hyperperfusion and compartment syndrome. Reducing the operation duration with the use of rapid popliteal artery release sensu A. N. Kazantsev reduces the time of intraoperative mechanical ventilation, which in COVID-19 patients reduces the risks of pneumothorax, pneumomediastinum, emphysema, and pulmonary embolism. Thus, the rapid popliteal artery release sensu A. N. Kazantsev can be recommended for popliteal thrombectomy in patients with COVID-19.

Age corrected changes in intracranial hemodynamics after carotid endarterectomy.

Transcranial Doppler ultrasound (TCD) is a frequently used method to monitor brain perfusion during and following carotid endarterectomy (CEA). Our aim was to define the normally occurring changes of intracranial hemodynamics in patients undergoing CEA measuring recently developed TCD parameters. A retrospective, single-center cohort study was performed. Patients undergoing CEA were evaluated pre- and postoperatively from day 0 to day 3 measuring middle cerebral artery flow velocity (MCAFV). The following parameters were analyzed: the first systolic peak (Sys1), the second systolic peak (Sys2) and diastolic flow velocity at a fixed time after heartbeat onset (Dias@560). These parameters linearly decrease with age and were, therefore, transformed to Z-scores. Three hundred eighteen patients were included with a mean age of 70.8 years. Most patients were male (71%). Compared to preoperatively, the Z-scores of Sys1 and Sys2 were larger on postoperative day 3: +1.12 standard deviation (SD) or 16.0 cm/s (CI: 0.93 to 1.32; P<0.001) and +0.55 SD or 7.8 cm/s (CI: 0.35 to 0.74; P<0.001), respectively. The Z-score for Dias@560 was smaller than preoperatively: -0.23 SD or -1.9 cm/s (CI: -0.41 to -0.05, P=0.015). Under normal circumstances Sys1 profits more from CEA than Sys2, whilst diastolic flow velocity decreases. This indicates a return to normal arteriolar vascular resistance. Carefully describing normal changes in MCAFV, may in future enable discrimination of abnormalities, such as hyperperfusion syndrome.

Dynamics of resistant hypertension in the postoperative period of carotid endarterectomy with and without carotid body saving

Aim. To analyze the results of multicenter study on dynamics of resistant hypertension (RH) in patients after various types of carotid endarterectomy (CE) with and without carotid body savingMaterial and methods. During the period from January 2010 to December 2020, 1827 patients with hemodynamically significant stenosis of the internal carotid artery (ICA) and RH were operated on. Depending on CE type, the two groups were selected. Group 1 (n=1135; 62,2%) consisted of patients received glomus-saving surgery: 19,2% (n=351) -conventional CE with a patch repair of reconstitution point; 13,6% (n=248) — glomus-saving CE sensu R. A. Vinogradov; 7,3% (n=133) — glomus-saving CE sensu K. A. Antsupov; 11,7% (n=214) — glomus-saving CE sensu A. N. Kazantsev; 4,6% (n=84) — Chick-Chirik CE; 5,7% (n=105) — swallow tail type patch repair sensu R. I. Izhbuldin. Group 2 (n=692; 37,8%) consisted of patients received CE without glomus saving: 18,6% (n=341) — eversion CE with carotid body cutoff; 6,3% (n=115) — CE with new bifurcation plasty; 5,85% (n=107) — autoarterial reconstruction; 7,1% (n=129) ICA autotransplantation sensu E. V. Rosseikin.Results. The mortality rate, as well as the prevalence of myocardial infarction (MI) and ischemic strokes were comparable in groups. The incidence of hemorrhagic transformation (group 1: 0%; group 2: 0,6%; p=0,04; OR=0,06; 95% CI, 0,003-1,25) and composite endpoint (death+MI+ischemic stroke+hemorrhagic transformation) (group 1: 1,06%; group 2: 3,0%; p=0,004; odds ratio (OR)=0,34; 95% CI, 0,16-0,69) significantly differs between groups. After glomus-saving CE, the number of patients with the target blood pressure (BP) level reached 51,1% (p &lt;0,0001; OR=0,0009; 95% CI, 6,05-15,9). The number of patients with grade II (31,1%; p&lt;0,0001; OR=12,7; 95% CI, 10,4-15,52) and III (3,6%; p&lt;0,0001; OR=10,26; 95% CI, 6,71-15,67) hypertension significantly decreased. In the group 2, the prevalence grade III hypertension increased (48,0%; p&lt;0,0001; OR=0,23; 95% CI, 0,18-0,3), while the number of patients with grade I (0%; p&lt;0,0001; OR=77,0; 95% CI, 4,71-12,58) and II (52%; p&lt;0,0001; OR=3,06; 95% CI, 2,43-3,86) hypertension decreased.Conclusion. Glomus-saving CE contributes to achieving target BP in patients with RH. Its removal increases the risks of labile hypertension, postoperative hypertensive crisis, hyperperfusion syndrome and hemorrhagic transformation.

Staged angioplasty: A sensible approach to prevent hyperperfusion syndrome after carotid artery stenting? A meta-analysis.

To investigate whether staged angioplasty (SAP) is a safe and effective treatment to prevent hyperperfusion syndrome after carotid artery stenting (CAS). A systematic literature search was performed according to established criteria to identify eligible articles published before October 2020. Pooled dichotomous data were presented as odds ratios (OR) and corresponding 95% confidence intervals (CI) using random-effect models. The efficacy endpoints were hyperperfusion syndrome (HPS), hyperperfusion phenomenon (HPP), and intracerebral hemorrhage (ICH). The safety endpoint was post-procedural thromboembolic events. The feasibility of the procedure was assessed by device-related adverse events (vessel dissection and failed angioplasty) in SAP. Ten studies (1030 participants) were eligible. SAP was superior to regular CAS in preventing HPS (OR = 0.35, 95% CI 0.14-0.86, P = 0.02). There was no significant difference in the rate of thromboembolic events between the SAP group and the regular CAS group. The rates of vessel dissection and failed angioplasty with the use of a 3.0-mm-diameter balloon were 5.4% and 0.4%, respectively. SAP may reduce the incidence of post-CAS HPS without increasing procedure-related complications. A 3.0-mm-diameter balloon used in SAP may be appropriate for Asian populations. However, the confounded study design and confused definitions of reporting items hinder the current recommendation of SAP in clinical use.

Ipsilateral hypoperfusion caused by intracerebral steal phenomenon after carotid artery stenting: a case report

BackgroundAbnormal hypoperfusion on the surgical side after carotid artery stenting is rare. Neurological deterioration caused by it is deceptive, which can easily lead to misdiagnosis. The mechanism of hypoperfusion has rarely been demonstrated. We present here a fully studied case with a high probability of intracerebral steal phenomenon.Case presentationA 68-year-old male with severe right internal carotid artery stenosis and left internal carotid artery occlusion underwent right stenosis stent implantation. Restlessness and left limb hemiplegia occurred within 24 h after the procedure, which was similar to hyperperfusion syndrome. However, postoperative computerized tomography perfusion (CTP) revealed abnormal hypoperfusion in the right hemisphere. Transcranial Doppler (TCD) also showed decreased flow velocity in the right middle cerebral artery, and increased flow velocity in the right anterior cerebral artery. We considered that intracerebral steal phenomenon might be the cause, then hypervolemic therapy was accepted and the symptoms completely resolved after 3 days.ConclusionsIpsilateral hypoperfusion is rarely seen after carotid artery stenting. Intracerebral steal phenomenon may be the underlying mechanism. CTP or TCD is helpful for the early detection of this adverse event.

Hypocapnia Induced by Hyperventilation with Indocyanine Green Kinetics Detects the Effect of Staged Carotid Angioplasty to Avoid Hyperperfusion in Patients with Impaired Cerebral Hemodynamic Reserve.

Cerebral hyperperfusion syndrome (CHS) is a serious complication following carotid artery stenting (CAS). Staged angioplasty (AP) could potentially prevent CHS and hyperperfusion phenomenon (HPP) after revascularization. However, methods for measuring the effects of staged AP on cerebral hemodynamic reserve have not been established. Here, we evaluated whether indocyanine green kinetics and near-infrared spectroscopy (ICG-NIRS) with hypocapnia induced by hyperventilation can detect the effects of staged AP on hemodynamic reserve to prevent CHS after CAS. Participants comprised 44 patients at high risk of CHS, whose ipsilateral cerebrovascular reactivity (CVR) was impaired on preoperative single photon emission computed tomography (SPECT). Patients were divided into a staged AP group (n=13) and a regular CAS group (n=31). In the staged AP group, stenting was performed 3 weeks after staged AP. In the regular CAS group, 16 cases (52%) showed HPP, and five (16%) presented with CHS after CAS, while no HPP or CHS occurred in the staged AP group (p=0.001). Changes in blood flow index (BFI) and time to peak (TTP) ratio during hypocapnia calculated from ICG-NIRS indicated a significant linear relationship with preprocedural CVR on SPECT (r=-0.710, 0.632, respectively; p<0.0001 each). BFI and TTP ratios during hypocapnia were significantly improved after staged AP (p<0.001 each). Furthermore, significant linear correlations were observed between BFI and TTP ratio during hypocapnia and postoperative asymmetry index AI (r=0.405, -0.475, respectively; p<0.01 each). Hypocapnia induced by hyperventilation under ICG-NIRS appears useful for detecting the effects of staged AP on hemodynamic reserve in patients at high risk of CHS.

Massive non-aneurysmal subarachnoid hemorrhage after cervical carotid angioplasty and stenting: A case report and review of the literature

IntroductionCarotid angioplasty and stenting (CAS) of the cervical segment is a safe and effective procedure for the treatment of carotid artery disease. In rare cases, this procedure causes intracranial hemorrhage (ICH), which is described most often as an ipsilateral intra-parenchymal hematoma. This ICH is the result of a cerebral hyperperfusion syndrome (CHS). Isolated subarachnoid hemorrhage may occur exceptionally, with only 9 cases that have been reported in the literature. ObservationWe reported a case of a 71-year-old man who presented a massive non-aneurysmal subarachnoid hemorrhage one hour after angioplasty and stenting of the cervical segment of the left internal carotid artery. Medical and surgical management included external ventricular drain placement. Rebleeding occurred two days later, worsening the patient's clinical condition. Finally, the patient died 2 weeks later. CommentsThis rare presentation of ICH following CAS allows us to discuss the risk factors, complications and management of CHS.

Thirty-Day Results of the Novel CGuard-Covered Stent in Patients Undergoing Carotid Artery Stenting

Objective: The aim of this study was to provide early-term evaluation, safety, and efficacy of the novel CGuard (Inspire MD, Tel Aviv, Israel) micromesh self-expanding stent with embolic protection system (EPS) during carotid artery stenting (CAS) procedure. Materials and Methods: All patients who underwent CAS with CGuard carotid stent system from January 2018 to September 2020 in a tertiary center were prospectively evaluated. Primary endpoints included technical success and perioperative neurological events (0–48 hours). Secondary endpoint was the rate of neurologic, cardiac events, and death (major adverse event or MAE) at 30 days. Patency of CGuard, peak systolic velocity (PSV), and end diastolic velocity (EDV) were evaluated at 30 days with duplex ultrasound. Results: A total of 103 patients underwent CAS procedure. Forty patients were symptomatic, and 63 patients were asymptomatic with stenosis greater than 70%. Technical success was 100%. Local anesthesia was applied in 94 patients (93%). Embolic protection devices were used in 6 patients (5.8%). Access site complications were 1.9%. Mean internal carotid artery stenosis diameter reduced from 79.47% to 14.68%. Two patients had transient ischemic attack (1.9%) and 1 patient experienced a cerebral hyperperfusion syndrome (CHS) perioperatively. External carotid artery (ECA) occlusion occurred in 1.9%. Four patients experienced jaw claudication (3.8%) postoperatively. Mean time of operation was 41 minutes. Mean duration of hospitalization was 3.1 days. The 30-day rate of MAE was 0%. CGuard patency was 100%, mean internal carotid PSV was reduced from 251.57 to 77.29 cm/s, and mean internal carotid EDV was reduced from 154.62 to 24.63 cm/s at 30 days. Conclusion: Our study shows that CGuard stent with EPS is an effective and safe device for treatment of carotid artery stenosis with acceptable low perioperative neurologic events, even with low embolic protection device usage. Larger multicenter and randomized studies are necessary to confirm its long-term efficacy.

Carotid Endarterectomy

Carotid artery stenosis is associated with an elevated incidence of stroke, and carotid endarterectomy is performed to prevent future strokes in cases of severe carotid artery stenosis. Patients presenting for carotid endarterectomy often have a number of comorbidities that make them challenging to anesthetize. Both regional and general anesthetic techniques may be successfully used, but with either, careful management of hemodynamics throughout the perioperative course is critical. During carotid cross-clamping, it is important to monitor the patient’s neurologic status to ensure adequate perfusion to the ipsilateral hemisphere, and for this, a number of neuromonitoring modalities are available, with EEG monitoring being the most common. Several potential complications require close monitoring of the patient in the immediate postoperative period. This review contains 6 figures, 7 tables, and 49 references. Key Words: carotid artery stenosis, carotid endarterectomy, carotid artery stenting, cerebral hyperperfusion syndrome, cervical plexus block, electroencephalography, neck hematoma, neuromonitoring, preoperative optimization, stroke, transcranial Doppler