Nε-(carboxymethyl)lysine Concentration in Debris from Carotid Artery Stenting Correlates Independently with Signal Intensity on T1-Weighted Black-Blood Magnetic Resonance Images.

BACKGROUND AND PURPOSE: Because magnetic resonance imaging (MRI) focuses on the morphological characteristics of carotid artery plaques, its diagnostic value with respect to plaque vulnerability is limited. We examined the correlation between Nε-(carboxymethyl)lysine (CML), a main chemical structure of advanced glycation end-products, and the vulnerability of plaques visualized on MRI scans. MATERIALS AND METHODS: We enrolled 43 patients who had undergone carotid artery stenting (CAS) for carotid artery stenosis; all underwent MRI studies, including black-blood MRI and diffusion-weighted imaging (DWI). The signal intensity ratio (SIR) of plaques to adjacent sternocleidomastoid muscle (P/M) on T1- and T2-weighted images (T1WI, T2WI) was calculated. Protein samples were extracted from debris trapped by a filter device. The concentrations of CML and myeloperoxidase (MPO) were measured by solid-phase enzyme-linked immunosorbent assay. RESULTS: The patients were classified into 2 groups based on their SIR-P/M on T1WI and T2WI scans. We observed a higher incidence of post-CAS DWI lesions in patients with a higher than a lower SIR-P/M on T1WI; the CML and MPO concentrations in their CAS debris were also higher. No such differences were seen in patients with a higher or lower SIR-P/M on T2WI scans. The concentration of CML in CAS debris correlated independently with the SIR-P/M on T1WI of the carotid plaques, and was related to the concentration of MPO in CAS debris. CONCLUSIONS: Our findings suggest CML as a candidate molecular imaging probe for the identification of vulnerable plaques.

Relationship between the Carotid Plaque T1 Relaxation Time and the Plaque-to-Muscle Signal Intensity Ratio on Black-Blood Magnetic Resonance Imaging Scans.

BACKGROUND: Black-blood magnetic resonance imaging (BB-MRI) is useful for the characterization and assessment of carotid artery plaques. The plaque-to-muscle signal intensity (SI) ratio (plaque/muscle ratio [PMR]) is used widely to evaluate plaques. However, the correlation between the PMR and the T1 relaxation time needs to be determined. We measured the T1 relaxation time of carotid plaques using T1 mapping and compared the results with the PMR on BB-MRI scans. METHODS: Between April 2014 and July 2015, 20 patients with carotid artery stenosis were treated by carotid artery stenting. All patients underwent preoperative magnetic resonance plaque imaging. The ratio of the plaque SI to the sternocleidomastoid muscle was calculated on T1-weighted BB-MRI scans. T1 mapping was performed in the region where the vessel was narrowest using the inversion recovery technique. The T1 relaxation time was recorded to determine whether there was a correlation with the PMR. RESULTS: The plaque T1 value was 577.3 ± 143.2 milliseconds; the PMR value obtained on BB-MRI scans was 1.23 ± .27. There was a statistically significant decrease in the T1 value as the PMR increased (P < .0001). CONCLUSIONS: As the T1 relaxation time was well correlated with the PMR on BB-MRI scans, the evaluation of vulnerable plaques using the PMR was reliable and convenient.

Relationship between Angiographic Results and Morphology in Sidewall Intracranial Aneurysms after Stent-Assisted Coil Embolization.

BACKGROUND: Stent-assisted coil embolization (SACE) is used to address wide-necked or complex aneurysms. However, as they may recanalize after SACE, predictors of recanalization are needed. We investigated the relationship between follow-up angiographic results and the morphology of sidewall (SW) aneurysms in patients treated by SACE. METHODS: Between September 2010 and September 2014, we performed 80 SACE procedures for SW intracranial aneurysms. Angiographic findings, obtained immediately after the procedure, 3-6 months thereafter, and when aneurysmal recanalization was suspected on MR angiogram scan, were recorded. Morphologically, the SW aneurysms were classified as "outside" (OS) and "partially inside" (PI) based on the curve of the axes of the proximal or distal parent artery with respect to the aneurysmal neck. Follow-up angiographic studies on OS- and PI SW aneurysms were compared. RESULTS: On the initial angiograms, we classified 42 aneurysms as OS and 38 as PI. Immediately after SACE, there was no significant difference in the angiographic findings on OS and PI aneurysms. However, on follow-up angiograms, there was a significant difference in the rate of spontaneous improvement (4 of 42 [OS] versus 21 of 38 [PI], P = .001). We performed additional coil embolization to treat 3 recanalized OS aneurysms. CONCLUSIONS: SW aneurysms classified morphologically as PI tended to occlude progressively even after incomplete occlusion by SACE. In contrast, aneurysms classified as OS must be observed carefully after SACE.

A manual carotid compression technique to overcome difficult filter protection device retrieval during carotid artery stenting.

BACKGROUND: We investigated the incidence of embolic protection device retrieval difficulties at carotid artery stenting (CAS) with a closed-cell stent and demonstrated the usefulness of a manual carotid compression assist technique. METHODS: Between July 2010 and October 2013, we performed 156 CAS procedures using self-expandable closed-cell stents. All procedures were performed with the aid of a filter design embolic protection device. We used FilterWire EZ in 118 procedures and SpiderFX in 38 procedures. The embolic protection device was usually retrieved by the accessory retrieval sheath after CAS. We applied a manual carotid compression technique when it was difficult to navigate the retrieval sheath through the deployed stent. We compared clinical outcomes in patients where simple retrieval was possible with patients where the manual carotid compression assisted technique was used for retrieval. RESULTS: Among the 156 CAS procedures, we encountered 12 (7.7%) where embolic protection device retrieval was hampered at the proximal stent terminus. Our manual carotid compression technique overcame this difficulty without eliciting neurologic events, artery dissection, or stent deformity. CONCLUSIONS: In patients undergoing closed-cell stent placement, embolic protection device retrieval difficulties may be encountered at the proximal stent terminus. Manual carotid compression assisted retrieval is an easy, readily available solution to overcome these difficulties.

The Safety and Efficacy of Triple Antiplatelet Therapy after Intracranial Stent-Assisted Coil Embolization.

BACKGROUND: Stent-assisted coil embolization is effective for intracranial aneurysms, especially for wide-necked aneurysms; however, the optimal antiplatelet regimens for postoperative ischemic events have not yet been established. We aimed at determining the efficacy and safety of a triple antiplatelet therapy regimen after intracranial stent-assisted coil embolization. METHODS: We retrospectively evaluated patients who underwent stent-assisted coil embolization for unruptured intracranial aneurysms or during the chronic phase of a ruptured intracranial aneurysm (≥ 4 weeks after subarachnoid hemorrhage onset). We recorded the incidence of ischemic and bleeding events 140 days postoperatively. RESULTS: We assessed 79 cases in patients who received either dual (n = 51) or triple (n = 28) antiplatelet therapy. The duration of triple antiplatelet therapy was 49 ± 29 days. Seven patients in the dual group experienced postoperative ischemic events. Compared to the dual group, the triple group had a similar incidence of postoperative bleeding events but a significantly lower incidence of postoperative ischemic events (P < .05). CONCLUSIONS: Triple antiplatelet therapy had a significantly lower incidence of postoperative ischemic events and a similar incidence of postoperative bleeding events 140 days postoperatively.

[Unruptured cerebral aneurysm associated with fenestration of the anterior cerebral artery successfully treated with coil embolization using an intracranial stent: a case report].

Recent sporadic reports have described successful endovascular treatment of cerebral aneurysms associated with fenestration. We experienced an unruptured cerebral aneurysm case, with fenestration of the horizontal portion of the anterior cerebral artery that was successfully treated with coil embolization using an intracranial stent. An 80-year-old man presented with a chief complaint of gait disorder. Magnetic resonance imaging showed an incidental unruptured aneurysm. Three-dimensional digital subtraction angiography revealed a cerebral aneurysm associated with fenestration of the horizontal portion of the anterior cerebral artery. Endovascular surgery was performed at the patient's request. Conservation of the fenestrated vessels and perforators is important in the treatment of cerebral aneurysm associated with fenestration. Intracranial stents are reportedly useful for conserving not only parent vessels but also their perforators. In the present case, no postoperative perforator damage occurred. An endovascular approach is a potential treatment option with full evaluation of the relationship between the aneurysm and fenestrated vessels.

Onset Time of Ischemic Events and Antiplatelet Therapy after Intracranial Stent-assisted Coil Embolization.

BACKGROUND: Stent-assisted coil embolization is effective for intracranial aneurysms, especially wide-necked aneurysms; however, the optimal antiplatelet regimens for ischemic events that develop after coil embolization have not yet been established. We aimed to determine the onset time of such postoperative ischemic events and the relationship between these events and antiplatelet therapy. METHODS: We performed coil embolization using a vascular reconstruction stent for 43 cases of intracranial aneurysms and evaluated the incidence of postoperative ischemic events in these cases. RESULTS: Nine patients showed postoperative ischemic events during the follow-up period (13 ± 7 months). Two patients developed cerebral infarction within 24 hours. Five patients developed transient ischemic attack within 40 days while they were receiving dual antiplatelet therapy. In addition, 1 patient showed cerebral infarction 143 days postoperatively during single antiplatelet therapy, and a case of transient visual disturbance was reported 191 days postoperatively (49 days after antiplatelet therapy had been discontinued). We increased the number of antiplatelet agents in 4 of these patients. The other 5 patients were under strict observation with dual antiplatelet therapy. All these patients were shifted to single antiplatelet therapy 3-13 months postoperatively. No recurrence of ischemic events was noted. CONCLUSIONS: Postoperative ischemic events are most likely to occur within 40 days postoperatively. For patients with postoperative ischemic events, additional ischemic events can be prevented by increasing the number of antiplatelet agents; subsequently, they can be shifted to single antiplatelet therapy after the risk of recurrence has decreased.

Nε-(carboxymethyl)lysine in debris from carotid artery stenting: multiple versus nonmultiple postoperative lesions.

BACKGROUND: No predictor of postoperative ischemic events has been identified in patients undergoing carotid artery stenting (CAS). We aimed to determine whether N(ε)-(carboxymethyl)lysine (CML) in debris trapped by an embolic protection filter device is a predictor of postoperative ischemic events. METHODS: We enrolled 27 patients (73.4 ± 7.2 years; 22 male, 5 female) who underwent CAS for carotid artery stenosis. Diffusion-weighted magnetic resonance imaging was performed before and after the procedure. Protein samples were extracted from the debris. CML and myeloperoxidase were examined by solid phase enzyme-linked immunosorbent assay and Western blot analysis. RESULTS: Seventeen patients had 0 or 1 new lesion (nonmultiple lesions) postoperatively, whereas 10 patients had 2 or more new lesions postoperatively (multiple lesions). The CML concentration of the protein sample was significantly higher in patients with multiple lesions than in those with nonmultiple lesions (6.26 ± 2.77 ng/mg protein and 3.36 ± 1.57 ng/mg protein, respectively; P = .010). Statin therapy for dyslipidemia was associated with a lower incidence of multiple lesions and a lower concentration of CML in the protein sample (P = .004 and P = .02, respectively). Receiver operating characteristic analysis showed that the area under the curve for CML was significantly greater than .5 (.877; 95% confidence interval, .742-1.00). CONCLUSIONS: CML derived from debris may distinguish between patients with postoperative multiple ischemic lesions and those with postoperative nonmultiple lesions who undergo CAS.

Fragmentation of calcified plaque after carotid artery stenting in heavily calcified circumferential stenosis.

INTRODUCTION: We assessed the morphological change of calcified plaque after carotid artery stenting (CAS) in vessels with heavily calcified circumferential lesions and discuss the possible mechanisms of stent expansion in these lesions. METHODS: We performed 18 CAS procedures in 16 patients with severe carotid artery stenosis accompanied by plaque calcification involving more than 75% of the vessel circumference. All patients underwent multidetector-row computed tomography (MDCT) to evaluate lesion calcification before and within 3 months after intervention. The angiographic outcome immediately after CAS and follow-up angiographs obtained 6 months post-CAS were examined. RESULTS: The preoperative mean arc of the calcifications was 320.1 +/- 24.5 degrees (range 278-360 degrees ). In all lesions, CAS procedures were successfully carried out; excellent dilation with residual stenosis

Intraprocedural plaque protrusion resulting in cerebral embolism during carotid angioplasty with stenting.

An 82-year-old man with an asymptomatic left high-grade carotid stenosis was treated with carotid artery stenting (CAS) under distal protection. The procedure consisted with predilation with a 5 x 40 mm percutaneous transluminal angioplasty (PTA) balloon, deployment of a 10 x 20 mm self-expandable stent, post-dilation with a 7 x 20 mm PTA balloon, and aspiration of debris with 60 ml of blood. The cervical carotid angiogram immediately after deflation of the distal blocking balloon demonstrated a small in-stent filling defect of the contrast medium that protruded from the anterior wall of the carotid artery. The following cranial carotid angiogram showed abrupt occlusion of the left middle cerebral artery (MCA). Because the in-stent lesion had vanished in the repeat study after recognition of this embolic event, it was suggested that an embolus had been liberated from the in-stent lesion, reaching the left MCA and obliterating it. In this case, the embolus was speculated to originate in the ruptured plaque, which protruded into the stent through the cells of the device and became liberated into the bloodstream. Attention should be paid so as not to overlook any plaque protrusion, which may be seen subsequently as a cerebral embolism on the angiogram obtained immediately after CAS.

Spasm induced by protection balloon during carotid artery stenting.

PURPOSE: The PercuSurge system is a distal balloon embolic protection device used for carotid artery stenting (CAS). We performed a retrospective study on the prognosis and clinical effects of spasms induced by the PercuSurge GuardWire system (PercuSurge-induced spasm). MATERIALS AND METHODS: We performed CAS in 118 carotid stenoses using the PercuSurge system. Of the 118 procedures, 31 (26.3%) of the patients experienced PercuSurge-induced spasm, and all underwent postoperative follow-up studies by cerebral angiography and antiplatelet treatment. RESULTS: On follow-up angiograms obtained a mean of 5.2 months (range 3-10 months) after CAS, all 31 PercuSurge-induced spasms had disappeared, and no delayed stenosis was found at the sites where the spasms had occurred. No ischemic events due to the spasms occurred during a mean follow-up of 13 months (range 3-32 months). CONCLUSION: In the hands of physicians experienced in endovascular surgery, CAS using the PercuSurge system is a safe method with which to treat patients with carotid stenosis. Our study demonstrated that PercuSurge-induced spasms had no morphological or clinical adverse effects.

Cerebral protection during retrograde carotid artery stenting for proximal carotid artery stenosis: technical note.

Carotid artery stenting for carotid bifurcation stenosis usually uses the transfemoral approach. However, in patients with proximal common carotid artery (CCA) stenosis, the guiding catheter is difficult to introduce into the narrow origin of the CCA without risking cerebral embolization before activation of the protection device. A technique of cerebral protection by internal carotid artery (ICA) clamping with or without simultaneous external carotid artery (ECA) clamping was used to treat patients with proximal CCA stenosis by the retrograde direct carotid approach. The carotid bifurcation was surgically exposed and retrograde catheterization was performed to approach the stenosis. The ICA was clamped during angioplasty and stenting to avoid cerebral embolization. The ECA was clamped simultaneously if any extracranial-intracranial anastomosis was present. None of five patients treated with this technique experienced ischemic complications attributable to this technique.

Rebleeding after endovascular embolization of ruptured cerebral aneurysms.

This study retrospectively reviewed 227 patients with ruptured solitary cerebral aneurysm who underwent endovascular embolization with detachable coils between March 1997 and March 2006 to establish the incidence of rebleeding after endovascular treatment for ruptured cerebral aneurysm and identify the risk factors. The site and size of the aneurysm, the interval between treatment and rebleeding, and the outcome were investigated in six of the 227 patients (2.6%) who rebled after treatment. Four patients had large or giant aneurysms located on the internal carotid artery at the origin of the posterior communicating artery. The interval between treatment and rebleeding was less than 1 year in four patients (mean 394.2 days). Two patients died, and the survivors had modified Rankin Scale scores of 0, 2, 3, and 4. Re-embolization was performed in four patients and no further bleeding occurred during the mean follow-up period of 1.9 years after re-treatment. Patients with giant aneurysms of the internal carotid artery are at increased risk for rebleeding. Re-treatment should be considered if there is conventional and/or magnetic resonance angiographic evidence of dome filling. Patients with ruptured cerebral aneurysms must be followed up with diagnostic imaging closely during the first 12 months post-embolization because rebleeding frequently occurs within 1 year after initial treatment. Re-embolization is safe and effective in patients with recurrent hemorrhage from aneurysms previously embolized with detachable coils.

Development of unusual collateral channel from the posterior meningeal artery after endovascular proximal occlusion of the posterior inferior cerebellar artery.

A 38-year-old man presented with a dissecting aneurysm of the left proximal posterior inferior cerebellar artery (PICA) manifesting as Wallenberg's syndrome. The patient was treated by endovascular occlusion of the aneurysm and parent artery. Immediately after the treatment, the PICA territory was supplied by collateral circulation via the ipsilateral anterior inferior cerebellar artery. Seven days later, endogenous revascularization of the distal PICA territory had occurred via collateral circulation from the posterior meningeal artery (PMA). This unusual collateral circulation was thought to occur through a pre-existing anastomotic channel between the primitive vessels of the PICA and the PMA during subclinical hypoperfusion of the distal PICA territory. This unusual case demonstrates the potential for delayed development of collateral circulation from the PMA to the PICA territory.

[Case of ruptured superior cerebellar artery dissection treated by endovascular embolization].

The authors herein report a case of a ruptured dissection of the superior cerebellar artery (SCA). A 68-year-old man presented with symptons of sudden headache and nausea. The CT scan revealed the presence of both a subarachnoid hemorrhage (SAH) and acute hydrocephalus. The left vertebral angiogram showed an fusiform dilatation in the cerebellomesencephalic segment of the left SCA. Endovascular embolization of the aneurysm and SCA was successfully performed using Guglielmi detachable coils (GDCs). No delayed ischemic deficits were observed after the treatment. A dissection of the distal segment of the SCA is a very rare occurrence. We believe endovascular embolization using GDCs to be an effective and less invasive therapy for the treatment of an SCA dissection with SAH.

Hemodynamic stability under general anesthesia in carotid artery stenting.

PURPOSE: The purpose of our study was to investigate the frequency of hemodynamic instability in patients undergoing carotid artery stenting (CAS) under general anesthesia using sevoflurane and nitrous oxide in oxygen. METHODS: A total of 97 consecutive CAS procedures were performed in 84 patients under sevoflurane anesthesia. The following hemodynamic variables were assessed: degree of systolic blood pressure change (deltaSBP) during CAS, hypotension, and bradycardia during and after CAS. RESULTS: During CAS, hypotension occurred in 43% of the patients, and bradycardia occurred in 14%. There was individual variation in the deltaSBP during CAS. Systolic blood pressure (SBP) change >50 mmHg was not seen in this series. After CAS, hypotension occurred in 24%, and bradycardia occurred in 10%. Cerebral infarction occurred in three cases. The stroke rate was 3.1% in this series. CONCLUSION: General anesthesia using sevoflurane and nitrous oxide in oxygen depressed barorecepter reflex sensitivity, induced hemodynamic stability under CAS, and may decrease the rate of occurrence of complications.

Dural AVFs of the cavernous sinus: transvenous embolization using a direct superficial temporal vein approach.

We present an alternative endovascular approach to treat dural anterio-venous fistulas (AVFs) of the cavernous sinus that drain only into the superior ophthalmic vein. Two cases of dural AVFs of the cavernous sinus producing increased intraocular pressure and diminishing visual acuity are reported. The cavernous sinus was accessed via the direct superficial temporal vein approach through the superior ophthalmic vein. Successful embolization was documented radiographically and clinically.

Endovascular treatment of anterior cerebral artery aneurysms using Guglielmi detachable coils: mid-term clinical evaluation.

PURPOSE: Clinical and angiographic evaluations were performed in 19 consecutive patients with anterior communicating artery (ACoA) aneurysms treated by Guglielmi detachable coil (GDC) embolization between March 1997 and April 1999. METHODS: The angiographic criteria for endovascular treatment were 1) small (< 15 mm) aneurysm with a neck smaller than the fundus and 2) distinguishable aneurysm neck and relationship to the parent artery. Initially, we also included patients with anticipated surgical difficulties. These criteria were later expanded to include patients with conditions amenable to surgical clipping. Eleven patients presented with subarachnoid hemorrhage (SAH), and eight patients were asymptomatic. The most recent clinical follow-up was obtained by telephone interview with the patients and with their close relatives, to examine post-treatment personality changes. RESULTS: Complete obliteration (68%) or near-complete obliteration (neck remnant) (32%) of the ACoA aneurysm was achieved in all patients. Six-month follow-up angiography performed in 15 patients demonstrated no recurrence of aneurysms. The clinical outcome was good recovery in 15 (80%), moderately disabled in one (5%), vegetative survival in one (5%), and death in two (10%). The patients who had good recovery did not demonstarate significant personality or behavioral change. No late rebleeding had occurred at the time of writing, a minimum of 33 months postoperatively. CONCLUSION: The outcome of endovascular treatment of ACoA aneurysms was satisfactory, especially in post-treatment psychosocial sequelae.

Internal carotid aneurysms presenting with mass effect symptoms of cranial nerve dysfunction: efficacy and imitations of endosaccular embolization with GDC.

OBJECTIVE: The authors report a retrospective analysis of their experience in the endosaccular embolization of internal carotid aneurysms which caused mass effect symptoms of cranial nerves (CN) and review the efficacy and limitations of this technique. METHODS: Between April 1997 and August 2002, 12 internal carotid aneurysms that caused mass effect symptoms of CN were treated by endosaccular GDC embolization with parent artery preservation. The locations were the cavernous internal carotid artery (CV) in six patients, carotid-ophthalmic artery (CO) in two patients, and posterior communicating artery (PCo) in four patients. The angiographical size of the aneurysms ranged from 6 to 20 mm, with a mean of 13.3 mm. Duration of symptoms ranged from 0.5 to 120 months, with a mean of 13.7 months. All aneurysms were treated by endosaccular guglielmi detachable coil (GDC) embolization with preservation of the internal carotid artery. RESULTS: Five patients (42%) had complete resolution of symptoms, four (33%) had significant improvement of symptoms, and three (25%) were unchanged. Immediate posttreatment angiographic studies revealed neck remnant (NR) in nine patients and dome filling (DF) in three patients. In one patient (case 10), the resolved symptoms became worse 29 months later. Follow-up angiograms were obtained in 10 patients, and recanalization was observed in four of them (40%). Transient thrombotic complication occurred in only one patient. The group with resolution or improvement of symptoms demonstrated a shorter duration of symptoms before GDC treatment (< or = 12 months). CONCLUSION: Even subtotal endosaccular embolization of aneurysms may reduce mass effect symptoms of cranial nerves. However, careful follow-up is needed because subtotal occlusion carries a future risk of growth.

Retrograde carotid stenting for isolated stenosis of the proximal common carotid artery--case report.

A 49-year-old female with a history of systemic hypertension and diabetes mellitus suffered transient right hemiparesis. Carotid angiography with arch-aortography detected severe stenosis of the proximal portion of the left common carotid artery. The left carotid bifurcation was surgically exposed and retrograde catheterization was performed to approach the proximal common carotid artery stenosis. The lesion was dilated with a balloon catheter and successfully stented without complications. The left internal carotid artery was clamped during the procedure to avoid embolism. Retrograde carotid stenting for stenosis of the proximal common carotid artery is a safe and effective alternative to conventional surgery in selected patients.