Permanent Internal Carotid Artery Occlusion Research Articles

Angiographic Predictors of Outcomes After Balloon Test Occlusion

Background Balloon test occlusion (BTO) with adjunctive single‐photon emission computed tomography has been used to predict tolerance after permanent internal carotid artery occlusion. Anatomic characteristics of the cerebral circulation might predict BTO outcomes and identify patients susceptible to test failure. Methods We performed a single‐center retrospective analysis of patients who underwent internal carotid artery BTO from July 2013 to June 2020. Patients who passed the clinical BTO underwent single‐photon emission computed tomography imaging; technetium‐99m‐ethyl cysteinate dimer was injected intravenously after 15 to 30 minutes of occlusion and induced hypotension. The diameter of the vessels of the circle of Willis was measured angiographically. Single‐photon emission computed tomography imaging hypoperfusion severity was classified as none, mild, low intermediate, high intermediate, and severe. A threshold vessel diameter with most predicted accuracy for BTO failure was created using the Youden index. The threshold value was tested in a logistic regression for prediction of BTO failure and accuracy as represented with a receiver operator curve. Results Fifty‐seven patients underwent BTO. Neoplasia was the most common indication (n=43, 75%). Twelve (21.1%) patients failed the clinical BTO. Contralateral dominant vertebral artery ( P =0.02), smaller anterior communicating artery (ACom; P =0.002), and ipsilateral posterior communicating artery ( P =0.03) diameters were correlated with clinical BTO failure. Smaller ACom was most predictive with an area under the curve of 0.907. The Youden index identified an ACom diameter threshold of 1.1 mm, with a sensitivity of 91.7% and specificity of 77.8% (odds ratio, 0.026 [95% CI, 0.003–0.226]; receiver operating characteristic, 0.847) for predicting BTO failure. Patients with severe single‐photon emission computed tomography asymmetry had significantly smaller‐caliber ACom arteries (ACom median diameter, 0.95 versus 1.4 mm; P =0.0073). Conclusions Angiographic findings can be used to predict BTO results. A small ipsilateral posterior communicating artery, and more significantly, a small ACom (<1.1 mm) can be used to identify patients who are likely to fail BTO.

Balloon Test Occlusion of Internal Carotid Artery in Recurrent Nasopharyngeal Carcinoma Before Endoscopic Nasopharyngectomy: A Single Center Experience.

ObjectivesEndoscopic nasopharyngectomy (ENPG) is a promising way in treating recurrent nasopharyngeal carcinoma (rNPC), but sometimes may require therapeutic internal carotid artery (ICA) occlusion beforehand. Balloon test occlusion (BTO) is performed to evaluate cerebral ischemic tolerance for ICA sacrifice. However, absence of neurological deficits during BTO does not preclude occur of delayed cerebral ischemia after permanent ICA occlusion. In this study, we evaluate the utility of near-infrared spectroscopy (NIRS) regional cerebral oxygen saturation (rSO2) monitoring during ICA BTO to quantify cerebral ischemic tolerance and to identify the valid cut-off values for safe carotid artery occlusion. This study also aims to find out angiographic findings of cerebral collateral circulation to predict ICA BTO results simultaneously.Material and Methods87 BTO of ICA were performed from November 2018 to November 2020 at authors’ institution. 79 angiographies of collateral flow were performed in time during BTO and classified into several Subgroups and Types according to their anatomic and collateral flow configurations. 62 of 87 cases accepted monitoring of cerebral rSO2. Categorical variables were compared by using Fisher exact tests and Mann–Whitney U tests. Receiver operating characteristic curve analysis was used to determine the most suitable cut-off value.ResultsThe most suitable cut-off △rSO2 value for detecting BTO-positive group obtained through ROC curve analysis was 5% (sensitivity: 100%, specificity: 86%). NIRS rSO2 monitoring wasn’t able to detect BTO false‐negative results (p = 0.310). The anterior Circle was functionally much more important than the posterior Circle among the primary collateral pathways. The presence of secondary collateral pathways was considered as a sign of deteriorated cerebral hemodynamic condition during ICA BTO. In Types 5 and 6, reverse blood flow to the ICA during BTO protected patients from delayed cerebral ischemia after therapeutic ICA occlusion (p = 0.0357). In Subgroup IV, absence of the posterior Circle was significantly associated with BTO-positive results (p = 0.0426).ConclusionAngiography of cerebral collateral circulation during ICA BTO is significantly correlated with ICA BTO results. Angiographic ICA BTO can be performed in conjunction with NIRS cerebral oximeter for its advantage of being noninvasive, real-time, cost-effective, simple for operation and most importantly for its correct prediction of most rSO2 outcomes of ICA sacrifice. However, in order to ensure a safe carotid artery occlusion, more quantitative adjunctive blood flow measurements are recommended when angiography of cerebral collateral circulation doesn’t fully support rSO2 outcome among clinically ICA BTO-negative cases.

The Value of syngo DynaPBV Neuro During Neuro-Interventional Hypotensive Balloon Occlusion Test.

This study explored the value of flat detector computed tomography based brain perfusion imaging in assessing patient's tolerance prior to the permanent internal carotid artery occlusion. Ten patients diagnosed with neurovascular diseases through digital subtracted angiography (DSA) were enrolled into this study. Temporary balloon occlusion test (BOT) was performed for each patient with hypotensive challenge. During the test, parametric color-coded quantitative DSA (CCQ-DSA) was generated to evaluate the venous filling symmetry on both hemispheres. In addition, cerebral blood volume (CBV) maps were acquired before and during the test. Regions of interests were defined to quantitatively extract CBV value from affected and unaffected hemispheres and calculate relative CBV (rCBV), indicating perfusion symmetry. All the patients showed good perfusion symmetry before the test with rCBV close to 1.00. During the test, good perfusion symmetry was detected in 7 patients with averaged rCBV 1.03 ± 0.06. Only short venous delay and no ischemic complications were recognized. One patient had neither neurologic deficits nor long venous delay detected, however, showed hyper-perfusion in specific regions in the CBV maps. Two patients failed to pass the test, which showed significantly low CBV value from the affected hemisphere with maximum rCBV reduction close to 45%. CBV map had in general good consistency with clinical manifestations as well as venous filling in the BOT. Besides, it may provide further evidence of hemodynamic variations and delayed ischemic complications, and thus, had a potential to reduce risks and increase treatment safety.

The application of cerebral blood volume software inassessing the cerebral blood volume comparative study on the clinical manifestations before and afterballoon occlusion testwith hypotension

Objective To discuss the application of cerebral blood volume software in assessing thecerebral blood volume (CBV) comparative study on the clinical manifestations before and after balloon occlusion test with hypotension.Aiming to find an objective indicator for balloon occlusion test with hypotensionwhich is the gold standard of occluding internal carotid artery (ICA).Methods 10 patients diagnosed with cerebrovascular disease through digital subtraction angiography (DSA) whounderwent balloon occlusion test (BOT) with hypotension from October 2012 to October 2013,including8 cases of carotid cavernous sinus (CCF),1 case of Giant aneurysm on ICA cavernous sinus segment,and 1 case of CCF and pseudoaneurysm.CBV maps were acquiredinSoftware Cerebral Blood Volumeby manual injection of 60 ml CM (370 g/L) before and after balloon occlusion test with hypotension within 15 minutes,from which mean relative CBV (rCBV) of regions of interest (ROIs) was comparedin the same axial view,The change of mean rCBV was compared with the change of clinical manifestations before and after Ballon Occlusion Test with hypotension.Results There were 10 patients were involved inthis study,of which,no ischemic complicationswere recognized in 8 patients.Good perfusion symmetry was detected with averaged rCBV 1.02 ± 0.06.in those 8 patients,1 patient underwent permanent ICA occlusion with a detachable balloonwithout acute or delayed neurologic deficit perceived.The others underwent nidus embolization with coils with keeping ICAunobstructed and got well recovered.Two patients failed to tolerate the BOT testwith hypotensionwho developed in disturbance of consciousness and the contralateral limb hemiplegia.CBVs from the affected hemisphere was significantly lower than those from the unaffected hemisphere in the corresponding regions with mean rCBV reduction close to 24％ and 21％.2 patients underwent nidus embolization with coils with keeping ICA unobstructed and got well recovered.Conclusion CBV maps have a good consistency with clinical manifestationsbefore and after balloonocclusion testwith hypotension.It can be an objective indicator for the gold standard of occluding ICA. Key words: Cerebral blood volume software; Cerebral blood volume; Balloon occlusion test with hypotension; Carotid-cavernous sinus

Monitoring of Balloon Test Occlusion of the Internal Carotid Artery by Parametric Color Coding and Perfusion Imaging Within the Angio Suite: First Results

Temporary balloon test occlusion (BTO) might be performed prior to procedures in which occlusion of the internal carotid artery (ICA) might be necessary. We tested the hypothesis that parametric color coding (PCC) of angiographic series (digital subtraction angiography (DSA)) along with the assessment of cerebral blood volume (CBV) in the angiography suite would simplify and enhance the identification of candidates who are most likely to tolerate occlusion. Fifteen patients underwent angiographic series (DSA) and perfusion imaging before and during BTO. Pre- and postocclusion DSA acquisitions were evaluated for venous delay by conventional methods ("eye balling") and by PCC measurements. Comparison of CBV values between the left and right hemisphere in 6 defined regions was performed. Values of venous delay by eye balling and PCC showed a high correlation (r = 0.87, p < 0.01). Bland-Altman plot indicated slightly lower values (-0.05 s) by the PCC method. One of the 15 patients developed an asymmetrical CBV map with an increase in CBV of more than one standard deviation in 3 of the 6 regions of interest (ROIs). Acquisition of angiographic series and perfusion imaging did not prolong the test occlusion time. PCC and CBV mapping are feasible during BTO. The use of PCC seems to simplify the ability to measure changes in venous filling delay. Perfusion imaging may show an increase in CBV in patients reaching the limits of cerebral autoregulation. These patients may be at risk for delayed infarction, even though they seem to tolerate temporary occlusion, and could be unsuitable candidates for permanent ICA occlusion.

Cerebral Blood Flow and Metabolism Measurement Using Positron Emission Tomography before and during Internal Carotid Artery Test Occlusions: Feasibility of Rapid Quantitative Measurement of CBF and OEF/CMRO2

Balloon test occlusion (BTO) of the internal carotid artery (ICA) combined with cerebral blood flow (CBF) study is a sensitive test for predicting the outcome of permanent ICA occlusion. However, false negative results sometimes occur using single photon emission tomography (SPECT). We have recently developed a rapid positron emission tomography (PET) protocol that measures not only the CBF but also the cerebral oxygen metabolism before and during BTO in succession. We measured acute changes in regional CBF and OEF/CMRO(2) before and during BTO in three cases with large or giant cerebral aneurysms using the rapid PET protocol. Although no patients showed ischemic symptoms during BTO, PET studies exhibited mildly to moderately decreased CBF (9∼34%) compared to the values obtained before BTO in all cases. The average OEF during BTO was significantly increased (21% and 43%) than that of before BTO in two cases. The two cases were considered to be non-tolerant for permanent ICA occlusion and treated without ICA sacrifice. Measurement of the CBF and OEF/CMRO(2) using a rapid PET protocol before and during BTO is feasible and can be used for accurate assessment of tolerance prediction in ICA occlusion.

A new model of focal cerebral ischemia in the miniature pig

The purpose of this set of studies is to design a minimally invasive, reproducible stroke model in the gyrencephalic brain. This paper provides information on both surgical technique and methods of quantification of ischemic damage to both gray and white matter in the miniature pig. Sixteen male miniature pigs were randomly divided into three groups and underwent transcranial surgery involving a frontotemporal approach with orbital rim osteotomy for permanent middle cerebral artery occlusion (MCAO; five animals), permanent internal carotid artery occlusion (ICAO; six animals), and a sham operation (five animals). Histological mapping and magnetic resonance (MR) imaging were used to delineate the areas of ischemic damage. The volumes of infarction measured directly from MR images were 16.2 +/- 1.1, 1.5 +/- 0.5, and 0.0 +/- 0.0 cm3 (mean +/- standard deviation [SD], p < 0.001) in the MCAO, ICAO, and sham-operated groups, respectively. The areas of ischemia identified through histological analysis and MR imaging showed a good correlation (r2 = 0.86, p < 0.0001). Immunohistochemical staining with an amyloid precursor protein (APP) antibody was used to evaluate axonal damage and calculate a total APP score for axonal damage of 44.8 +/- 2.9 in the MCAO, 13.2 +/- 6.6 in the ICAO, and 0.0 +/- 0.0 (mean +/- SD, p < 0.002) in the sham-operated animals. This new model of focal cerebral ischemia induces a reproducible amount of ischemic damage in both gray and white matter, and has significant utility for studies of the pathophysiology of ischemia in the gyrencephalic brain and for assessment of the therapeutic efficacy of drugs prior to the initiation of human clinical trials.

Stent Graft Placement for the Treatment of Giant Aneurysm at the Proximal Cavernous Internal Carotid Artery

Cavernous giant aneurysm is a challenging lesion for both surgical and endovascular treatments. Using a skull base technique, some cavernous internal carotid artery (ICA) aneurysms are directly clipped. However, larger aneurysms frequently lead to adverse effects during and after the operation. Endovascular treatment of cavernous ICA aneurysm consists of endosaccular coil placement and permanent ICA occlusion with or without EC-IC bypass1,2,3. Endosaccular occlusion of giant aneurysm has been proven less efficient because of coil compaction and/or regrowth of aneurysm. We report a case of giant cavernous ICA aneurysm treated with stent graft placement.

Proximal intracranial internal carotid artery branches: prevalence and importance for balloon occlusion test

The aim of this study was to determine the prevalence of angiographically identifiable skull base arterial branches that potentially serve as collateral conduits during a balloon occlusion test (BOT) of the internal carotid artery (ICA). The authors posited that neurological deficits in patients who had previously tolerated the occlusion test may be attributable to an unrecognized collateral support through these channels (operant during proximal ICA BOT) when permanent ICA occlusion was performed more distally. In 481 cases (962 ICAs), cerebral angiograms obtained during routine Wada testing were retrospectively reviewed. Two hundred sixty-one patients had at least one angiographically identifiable ICA branch; 109 patients had two or more branches. A meningohypophyseal branch of the cavernous ICA was identified on the right side in 108 patients and on the left in 122. A vidian artery originated from the petrous portion of the ICA on the right side in 58 patients and on the left in 85. The inferolateral trunk revealed itself as a branch of the cavernous ICA on the right side in 17 patients and on the left in 33. A caroticotympanic artery arose from a left cavernous ICA. A persistent trigeminal artery was situated on the right side in two patients and on the left in three. More than half of the patients had angiographically identifiable and perhaps hemodynamically significant skull base branches of the ICA, and approximately one quarter had more than one identifiable branch. The authors recommend that patients be screened during angiography studies performed prior to BOT in branches of the proximal intracranial ICA and that the site of BOT be moved distally if such branches are identified.

Combined Surgical and Endovascular Treatment of Infected Pseudoaneurysm After Carotid Endarterectomy-Case Report-

A 67-year-old male presented with a rare pseudoaneurysm caused by infection after carotid endarterectomy (CEA) performed for stenosis of the left internal carotid artery (ICA). Wound infection and recurrent bleeding from the operated ICA developed 1 month after surgery. Serial angiography showed that the post-CEA pseudoaneurysm gradually increased in size. The carotid balloon occlusion test revealed that the patient could not tolerate permanent ICA occlusion because of poorly developed collaterals. Direct surgical exposure of the aneurysm was impossible due to tight adhesion of the surrounding tissue, so common carotid to middle cerebral artery bypass using a radial artery graft was performed followed by ligation of the distal common carotid artery. Subsequently, retrograde blood flow from the ICA to the aneurysm was interrupted by embolization of the external carotid artery coil through the facial artery. Combined surgical and endovascular treatment is a therapeutic option for patients with post-CEA pseudoaneurysm, if either direct or endovascular surgery is unfeasible.

Occlusion of the Internal Carotid Artery Based on a Simple Tolerance Test

In order to evaluate the safety of the internal carotid artery (ICA) occlusion based on our simple tolerance test, we reviewed 142 consecutive tolerance tests. Permanent endovascular ICA occlusion was performed on 99; a tolerance test only was performed on the remaining 43. Our assessment consisted of 1) angiographic evaluation of collateral circulations without and with ICA test occlusion, 2) evaluation of clinical tolerance to balloon ICA occlusion for 15-20 minutes. Complications of test and permanent ICA occlusion were retrospectively analyzed. Complications related to test occlusion occurred in 2 cases (1.4%) without causing permanent deficits. Complications related to permanent occlusion occurred in 16 cases (16%) including 2 technical, 10 temporary (10%) and 4 permanent (4%). Complications were significantly decreased after introduction of stringent postoperative care to prevent hypotension in 1987. Since 1988, we performed 47 permanent ICA occlusion and experienced no technical, 3 temporary (6%) and no permanent complications. Our method to evaluate tolerance to ICA occlusion is simple and safe. Reliability of the results is comparable to other more complicated methods of assessing ICA occlusion.

Endovascular balloon occlusion test of the internal carotid artery with increased hemodynamic monitoring for determination of circulatory reserve before planned carotid occlusion

To evaluate stroke risk assessment of balloon test occlusion of the internal carotid artery (ICA) with enlarged haemodynamic monitoring prior to permanent ICA occlusion. 24 patients with cervical metastasis (n = 18), cavernous meningiomas (n = 3) or inoperable cavernous aneurysms (n = 3) were examined. The test occlusion was monitored by EEG, neurological examinations and transcranial Doppler sonography of the ipsilateral middle cerebral artery with evaluation of the cerebrovascular reserve capacity. Additionally 99mTc-HMPAO-SPECT imaging was added showing the perfusion during test occlusion. In one (4%) patient the test occlusion had to be interrupted previously due to an acute neurological deficit. This patient and two (8%) patients with highly pathological test results in SPECT and TCD were excluded from permanent carotid occlusion. In 6 (25%) patients quantitative TCD monitoring could improve the stroke risk assessment by differentiating the patients in a low and high risk group. 6 (25%) patients were definitely occluded without haemodynamic complications, but two patients suffered from embolic infarctions which cannot be predicted by this procedure. The multimodal balloon test occlusion with enlarged haemodynamic monitoring allows haemodynamic stroke risk assessment prior to permanent occlusion of the ICA.

Aneurysms of the intracavernous carotid artery: a multidisciplinary approach to treatment

Of 43 cavernous sinus aneurysms diagnosed over 6 1/2 years, 23 fulfilled indications for treatment; of these 19 were treated, eight surgically and 11 with interventional radiological techniques. Six small and two giant aneurysms were treated surgically: four were clipped, two were repaired primarily, and two were trapped with placement of a saphenous-vein bypass graft. Seven large and four giant aneurysms were treated with interventional radiological techniques: in five cases the proximal internal carotid artery (ICA) was sacrificed; one aneurysm was trapped with detachable balloons; and five were embolized with preservation of the ICA lumen. The mean follow-up period was 25 months. At follow-up examination, three patients in the surgical group were asymptomatic, two had improved, and three had worsened. Three of these patients had asymptomatic infarctions apparent on computerized tomography (CT) scans. At follow-up examination, four radiologically treated patients were asymptomatic, five had improved, two were unchanged, and none had worsened. One patient had asymptomatic and one minimally symptomatic infarction apparent on CT scans; both lesions were embolic foci after aneurysm embolization with preservation of the ICA. It is concluded that treatment risk depends more on the adequacy of collateral circulation than on the size of the aneurysm. A multidisciplinary treatment protocol for these aneurysms is described, dividing patients into high-, moderate-, and low-risk groups based on pretreatment evaluation of the risk of temporary or permanent ICA occlusion using a clinical balloon test occlusion coupled with an ICA-occluded stable xenon/CT cerebral blood flow study. Radiological techniques are suggested for most low-risk patients, while direct surgical techniques are proposed for most moderate- and high-risk patients.