Hyperperfusion Syndrome In Patients Research Articles

Combination of intraoperative indocyanine green video-angiography FLOW 800 and computed tomography perfusion to assess the risk of cerebral hyperperfusion syndrome in chronic internal carotid artery occlusion patients after revascularization surgery.

To study the changes of corticocerebral hemodynamics in surgical area and postoperative hyperperfusion syndrome in patients with chronic internal carotid artery occlusion (CICAO) by intraoperative indocyanine green videoangiography (ICGA)-FLOW 800 and CT perfusion after superficial temporal artery (STA)-middle cerebral artery (MCA) bypass surgery. From October 2019 to January 2021, 77 patients diagnosed with CICAO underwent direct bypass surgery at Huadong hospital (affiliated with Fudan University) were enrolled. Regions of interest (ROIs) at STA, proximal MCA (PMCA), distal MCA (DMCA), cortical blood capillary (CBC), and cortical vein (CV) were identified after anastomosis by ICGV-FLOW 800 including peak fluorescence intensity (PFI), time to peak (TTP), and area under the time curve (AUC) of fluorescence intensity. All patients underwent perfusion-weighted CT before bypass surgery and those patients with HPS were verified by CTP after bypass. 14 patients with HPS were verified by perfusion-weighted CT after bypass. In HPS group, the AUCTTP of DMCA was significantly larger (T = -3.301, p = 0.004) and TTP of CBC was shorter (T = -2.929, p = 0.005) than patients in non-HPS group. The larger AUCTTP of DMCA (OR = 3.024, 95%CI 1.390-6.578, p = 0.0050) was an independent risk factor by further multivariate logistic regression analysis. The hemodynamic changes of cortical vessels during STA-MCA bypass surgery could be recorded accurately by ICGV-FLOW 800. Furthermore, the increased AUCTTP of DMCA and shorter TTP of CBC may be potential risk factors of HPS.

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.

Non-invasive assessment of cerebral microvascular changes for predicting postoperative cerebral hyperperfusion after surgical revascularisation for moyamoya disease: an arterial spin labelling MRI study

Cerebral hyperperfusion syndrome (CHPS) can result after anastomotic surgery as the reperfusion is established in chronically ischemic cerebral territories in patients of moyamoya disease (MMD). In this study, we have evaluated the feasibility of arterial spin labelling (ASL) perfusion MRI to predict cerebral hyperperfusion syndrome based on changes of cerebral blood flow (CBF) after revascularisation surgery in patients of MMD. Our prospective study included 25 patients with MMD who underwent superficial temporal artery-middle cerebral artery (STA-MCA) bypass with or without dural/muscle synangiosis. ASL MRI was performed before and 1-7days after surgery. On the side planned for operation, 5-mm ROI circle was drawn on the predetermined regions in frontal lobe, temporal lobe, parietal lobe and basal ganglia in proximal and distal territories of MCA to calculate ipsilateral CBF values (CBFi). An attempt was made to select the same location on contralateral side (non-operative) (CBFc) for each measurement for calculation of hemispheric normalised CBF (nCBFh) ratios. To adjust for inter individual variation among MR imagers and CBF, additional regions of interest were drawn within the cerebellum (CBFcbl) for cerebellar CBF normalised ratios (nCBFCbl). Of the 25 patients (26 operated hemispheres), 5 patients showed significant immediate postoperative symptoms suggestive of CHPS. Based on our findings, sensitivity and specificity of ASL perfusion to detect CHPS were evaluated. ASL was found to have 47-100% sensitivity and 45-88% specificity to detect CHPS. We have tried to calculate the prevalence of CHPS in postoperative patients of moyamoya disease, which in our study ranged from 6.83 to 40.70%. Based on our results, we concluded that ASL perfusion is an appropriate alternative to standard nuclear medicine studies to monitor the changes in perfusion after STA-MCA bypass surgery in moyamoya patients. ASL MR perfusion can be used to identify changes in cerebral blood flow (CBF) for early detection of cerebral hyperperfusion syndrome in patients with otherwise normal conventional MRI sequences with very high sensitivity but moderate specificity.

Evaluation of Hemodynamic Change by Indocyanine Green-FLOW 800 Videoangiography Mapping: Prediction of Hyperperfusion Syndrome in Patients with Moyamoya Disease.

Objective Hyperperfusion syndrome (HPS) after bypass surgery for moyamoya disease (MMD) mainly results from redistribution of blood flow, which leads to poor outcomes, while effective methods to predict HPS are still lacking. Indocyanine green (ICG) videoangiography can assess regional cerebral blood flow changes semiquantitatively with the application of FLOW 800 software. The purpose of this study was to investigate whether the intraoperative evaluation of local hemodynamic changes around anastomotic sites using FLOW 800 videoangiography mapping can predict the incidence of HPS and clinical outcomes. Methods Of the patients who were diagnosed with MMD in our hospital between August 2018 and December 2019, who underwent superficial temporal artery-middle cerebral artery bypass surgeries, we investigated 65 hemispheres (in 62 patients) in which intraoperative ICG analysis was performed using FLOW 800 (Zeiss Meditec, Oberkochen, Germany) to evaluate the local cerebral hemodynamics before and after anastomosis. Regions of interest were set at more than 2 points on the brain surface according to the location and situation of recipient arteries in the surgical area. Peak cerebral blood volume (CBV), regional cerebral blood flow (CBF), and time to peak (TTP) were calculated from the selected points. As the data were available intraoperatively, anastomoses were performed in a suitable area. According to the occurrence of HPS, patients were divided into the asymptomatic and symptomatic groups, from which hemodynamic parameters were compared. Furthermore, ROC analysis was performed to determine the diagnostic accuracy of change rates in CBV, CBF, and TTP (i.e., ΔCBV, ΔCBF, and ΔTTP) for predicting HPS. Results Data from the 62 patients were analyzed, and all patients were closely assessed during hospitalization after the procedures. The values of ΔCBV and ΔCBF were significantly higher in the symptomatic group (p < 0.01), while ΔTTP is slightly lower in the symptomatic group with no statistical differences (p = 0.72). Hemodynamic parameters including ΔCBV and ΔCBF, calculated by FLOW 800, had high sensitivity and specificity according to the ROC curve (ΔCBV: AUC = 0.743, 95% CI, 0.605–0.881, p = 0.002; ΔCBF: AUC = 0.852, 95% CI, 0.750–0.954, p < 0.01), which could be used as predictors for HPS. Conclusions Intraoperative ICG-FLOW 800 videoangiography mapping is a safe method which can reflect hemodynamic characteristics in the surgical area for MMD, the findings of which correlate with the occurrence of HPS. Parameters including ΔCBV and ΔCBF are proven to be efficient in the prediction of HPS.

Asymmetric Cortical Vessel Sign Indicates Hemodynamic Deficits in Adult Patients with Moyamoya Disease

Asymmetric cortical vessel sign (ACVS) on susceptibility-weighted imaging (SWI) indicates elevated concentration of deoxyhemoglobin and elevated oxygen extraction fraction in patients with cerebral ischemia. This study aimed to clarify whether ACVS is associated with impaired hemodynamics and hyperperfusion syndrome in patients with moyamoya disease (MMD). Consecutive adult patients with MMD were enrolled. ACVS data on SWI and perfusion data using dynamic perfusion computed tomography were obtained and evaluated preoperatively and on postoperative days 2 and180. A total of 24 patients with MMD were enrolled. Of 11 (45.83%) patients showing positive ACVS before surgery, 8 turned negative on postoperative day 2 and 9 showed absence of ACVS 180 days after surgery. Regions of interest showing positive ACVS had lower cerebral blood flow (CBF, P<0.001), increased cerebral blood volume (P= 0.021), prolonged time to peak (P<0.001), and mean transit time (P= 0.009). No patients with hemorrhagic symptoms showed positive ACVS(P= 0.041) and patients with positive ACVS showed more increase in CBF (P<0.004). In patients with MMD, ACVS on SWI indicates severe impairment in hemodynamics and is associated with more increase in CBF after bypass surgery. Hence, ACVS on SWI might be considered as a neuroimaging marker for the evaluation of hemodynamics in patients with MMD.

Abstract TP156: A Novel and Logical Strategy for Prevention of Hyperperfusion Syndrome; Intentional Residual Stenosis After Carotid Artery Stenting of an Extremely High-Grade Stenosis

Introduction: Hyperperfusion syndrome ( HPS ) probably occurs after carotid artery stenting ( CAS ) of an extremely high-grade carotid artery stenosis (ex-CS). However, it has not been established how to prevent HPS. Hypothesis: Intentional residual stenosis (iRS ) after CAS not followed by balloon dilatation (bD) can prevent HPS in patients with an ex-CS and spontaneously dilates thereafter. Methods: We included in our study patients with an ex-CS who underwent elective CAS not followed by bD for iRS from 2015 to 2018. We defined an ex-CS as a stenosis of more than NASCET 70% which caused delayed filling of contrast material in an internal carotid angiogram and reduced signal intensity (ratio of less than 0.9) of the ipsilateral middle cerebral artery (MCA) compared to the contralateral MCA on magnetic resonance angiograms (MRA), and defined a residual stenosis (rS) as angiographic stenosis of more than NASCET 30% or peak systolic velocity (PSV) of more than 80 cm/s by Doppler ultrasonography. We defined hyperperfusion phenomenon (HPP) as increase of cerebral blood flow in single photon emission computed tomography scans or cerebral metabolic rate of oxygen by measuring blood oxygen content. We evaluated patients’ baseline characteristics, rS just after CAS, incidence of HPS and HPP. Three months after CAS, they underwent conventional angiographic investigation. Results: During the study period, 26 CAS met our inclusive criteria. Their median carotid stenosis was NASCET 81.8%. Signal intensity ratio of MRA was 0.75. Median PSV before and just after CAS was 311.5 and 76.1 cm/s (p&lt;0.0001). Just after CAS, median stent diameter stenosis was 33.3%. Seventeen patients (65.4%) had angiographic rS. Twelve patients (46.2%) had PSV of more than 80 cm/s. Ten patients had both. Comprehensively nineteen (73.1%) patients had significant rS. Among 26 patients with an ex-CS, no one experienced HPS, although comprehensively 15 patients (57.7%) presented asymptomatic HPP. Among 26 patients, 23 patients finished 3-month angiography and their stents significantly spontaneously dilated (p&lt;0.0001). Conclusion: Intentional residual stenosis after CAS of an ex-CS probably prevented hyperperfusion syndrome and spontaneously dilated at 3 months after CAS.

CEREBRAL HYPERPERFUSION SYNDROME IN PATIENTS WITH STENOTIC AND OCCLUSIVE LESION INTERNAL CAROTID ARTERIES AFTER SURGERY. LITERATURE REVIEW

The literature on the cerebral hyperperfusion syndrome in patients with stenotic and occlusive lesion internal carotid arteries after surgery has been analyzed.Data of pathogenesis, clinical features, diagnostics, prevention and treatment of cerebral hyperperfusion syndrome are presented. Despite a large number of publications, there are no unified recommendations on treatment and prevention of cerebral hyperperfusion, there are no unified diagnostic criteria. Key words: cerebral hyperperfusion syndrome, EC-IC bypass, carotid endarterectomy, carotid artery stenting.

Intraoperative dexmedetomidine and postoperative cerebral hyperperfusion syndrome in patients who underwent superficial temporal artery-middle cerebral artery anastomosis for moyamoya disease: A retrospective observational study.

Dexmedetomidine, a selective α2-agonist, reduces cerebral blood flow and has neuroprotective effects against cerebral ischemia/reperfusion injury in experimental animals. We examined whether intraoperative dexmedetomidine would reduce the incidence of postoperative cerebral hyperperfusion syndrome (CHS) after superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis in patients with moyamoya disease.The electronic medical records of 117 moyamoya patients who underwent STA-MCA anastomosis were reviewed retrospectively. The patients were divided into 2 groups: 48 patients received intraoperative dexmedetomidine (Group D), while 69 patients did not (Group ND). The incidence (primary outcome), onset, and duration of postoperative CHS were noted.The incidence of postoperative CHS was 45.8% and 40.6% in groups D and ND, respectively (P = 0.708). The duration of postoperative CHS was shorter in group D than in group ND (median [Q1–Q3], 5 [3–7] vs 8 [5–10] days, P = 0.021). There was no significant difference in the onset of CHS between group D and group ND (0 [0–2] vs 1 [0–3] days, P = 0.226).In conclusion, intraoperative dexmedetomidine did not reduce the incidence of postoperative CHS, although it reduced the duration of CHS, in patients who had undergone direct revascularization surgery for moyamoya disease.

The Role of Perfusion Computed Tomography in the Prediction of Cerebral Hyperperfusion Syndrome

BackgroundHyperperfusion syndrome (HPS) following carotid angioplasty with stenting (CAS) is associated with significant morbidity and mortality. At present, there are no reliable parameters to predict HPS. The aim of this study was to clarify whether perfusion computed tomography (CT) is a feasible and reliable tool in predicting HPS after CAS.Methodology/Principal FindingsWe performed a retrospective case-control study of 54 patients (11 HPS patients and 43 non-HPS) with unilateral severe stenosis of the carotid artery who underwent CAS. We compared the prevalence of vascular risk factors and perfusion CT parameters including regional cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), and time to peak (TTP) within seven days prior to CAS. Demographic information, risk factors for atherosclerosis, and perfusion CT parameters were evaluated by multivariable logistic regression analysis. The rCBV index was calculated as [(ipsilateral rCBV - contralateral rCBV)/contralateral rCBV], and indices of rCBF and TTP were similarly calculated. We found that eleven patients had HPS, including five with intracranial hemorrhages (ICHs) of whom three died. After a comparison with non-HPS control subjects, independent predictors of HPS included the severity of ipsilateral carotid artery stenosis, 3-hour mean systolic blood pressure (3 h SBP) after CAS, pre-stenting rCBV index >0.15 and TTP index >0.22.Conclusions/SignificanceThe combination of severe ipsilateral carotid stenosis, 3 h SBP after CAS, rCBV index and TTP index provides a potential screening tool for predicting HPS in patients with unilateral carotid stenosis receiving CAS. In addition, adequate management of post-stenting blood pressure is the most important treatable factor in preventing HPS in these high risk patients.