Stent retrieval for free-floating thrombus attached to carotid artery stenosis: A report of two cases.

Background: We report two cases who underwent mechanical thrombectomy using a stent retriever in advance of urgent carotid artery stenting (CAS) for carotid artery stenosis with free-floating thrombus (FFT). Case Description: Two patients showing symptomatic carotid artery stenosis with FFT underwent urgent endovascular surgery due to progressive neurological symptoms. The first case showed an FFT with 70% internal carotid artery (ICA) stenosis. After the completion of the common and external carotid artery balloon and distal ICA filter protection, we deployed a 6-mm-diameter stent retriever in the distal part of the stenosis. The white thrombus was retrieved; the angiographic shadow of the FFT disappeared; and CAS was performed. In the second case, due to a 90% severe stenosis lesion with FFT, balloon angioplasty was performed on the lesion using the push wire of the stent retriever. After angioplasty, the stent retriever was smoothly retrieved, and CAS was performed. Postoperative magnetic resonance imaging showed an increase in cerebral embolism in the first case; however, the patient's neurological symptoms improved. The second case showed in-stent plaque protrusion and required two additional stent placements; the patient showed no worsening of his neurological symptoms. Conclusion: In cases of carotid artery stenosis with FFT, it is technically possible to retrieve a thrombus with a stent retriever. Although thrombus removal may help reduce the risk of ischemic complications in a series of urgent CAS procedures, there are concerns such as mechanical irritation to the carotid artery plaque, and its indications and alternative treatments should be carefully considered.

Evaluation of Serial Intra-Arterial Indocyanine Green Videoangiography in the Surgical Treatment of Cranial and Craniocervical Junction Arteriovenous Fistulae: A Case Series.

BACKGROUND AND OBJECTIVES: Intravenous indocyanine green (IV-ICG) videoangiography is commonly performed to detect blood flow in the microscopic view. However, intra-arterial ICG (IA-ICG) videoangiography provides high-contrast imaging, repeatability within a short period of time, and clear-cut separation of the arterial and venous phases compared with IV-ICG. These features are useful for detecting retrograde venous drainage (RVD) and shunt occlusion in arteriovenous fistulae (AVF) surgery. This study aimed to investigate whether IA-ICG videoangiography can be repeatable within a short period of time and be useful for detecting RVD and shunt occlusion in cranial- and craniocervical junction (CCJ)-AVF surgery. METHODS: Between January 2012 and December 2022, 50 patients were treated with endovascular or surgical intervention for cranial- and CCJ-AVF at Tokushima University Hospital. Of these, 5 patients (6 lesions) underwent open surgery with IA-ICG videoangiography in a hybrid operating room. We analyzed the data of these 5 patients (6 lesions). RESULTS: There were 4/patient (median, range 2-12) and 3.5/lesion (median, range 2-10) intraoperative IA-ICG runs. IA-ICG videoangiography detected RVD in all patients. Clearance of IA-ICG-induced fluorescence was achieved within 30 seconds in all patients at each region of interest. After the disconnection of the fistulae, IA-ICG videoangiography and intraoperative digital subtraction angiography (DSA) confirmed the disappearance of RVD in all patients. There were no complications associated with IA-ICG videoangiography. CONCLUSION: This study showed that IA-ICG videoangiography is repeatable within a short period of time before and after obliteration and can be useful for detecting RVD and shunt occlusion in cranial- and CCJ-AVF surgery. IA-ICG videoangiography also allows intraoperative DSA studies in a hybrid operating room. Considering the recent advancements in hybrid operating rooms, combining IA-ICG videoangiography with intraoperative DSA is a useful strategy for cranial- and CCJ-AVF surgery.

Efficacy of Utilizing Both 3-Dimensional Multimodal Fusion Image and Intra-Arterial Indocyanine Green Videoangiography in Cerebral Arteriovenous Malformation Surgery.

OBJECTIVE: An understanding of the complex morphology of an arteriovenous malformation (AVM) is important for successful resection. We have previously reported the utility of intra-arterial indocyanine green (ICG) videoangiography for this purpose, but that method cannot detect the angioarchitecture covered by brain tissue. 3-dimensional (3D) multimodal fusion imaging is reportedly useful for this same purpose, but cannot always visualize the exact angioarchitecture due to poor source images and processing techniques. This study examined the results of utilizing both techniques in patients with AVMs. METHODS: Both techniques were applied in 12 patients with AVMs. Both images were compared with surgical views and evaluated by surgeons. RESULTS: Although evaluations for identifying superficial feeders by ICG videoangiography were high in all cases, the more complicated the AVM, the lower the evaluation by 3D multimodal fusion imaging. Conversely, evaluation of the estimated range of the nidus was high in all cases by 3D multimodal fusion imaging, but low in all but one case by ICG videoangiography. Nidus flow reduction was recognized by Flow 800 analysis obtained after ICG videoangiography. CONCLUSIONS: These results showed that utilizing both techniques together was more useful than each modality alone in AVM surgery. This was particularly effective in identifying superficial feeders and estimating the range of the nidus. This technique is expected to offer an optimal tool for AVM surgery.

Efficacy of intraarterial indocyanine green videoangiography in surgery for arteriovenous fistula at the craniocervical junction in a hybrid operating room: illustrative cases.

BACKGROUND: Sufficient understanding of the angioarchitecture of an arteriovenous fistula (AVF) at the craniocervical junction (CCJ) is crucial to surgical treatment but is often difficult because of the complex vascular anatomy. Intraarterial indocyanine green (ICG) videoangiography has emerged as a more useful option for understanding the vascular anatomy than intravenous ICG videoangiography. This report describes two cases of CCJ AVFs successfully treated by surgery using intraarterial ICG videoangiography and describes the efficacy of this technique. OBSERVATIONS: Case 1 involved a 71-year-old man presenting with tetraparesis after sudden onset of severe headache due to subarachnoid hemorrhage (SAH). Digital subtraction angiography (DSA) demonstrated CCJ epidural AVF. Intraarterial ICG videoangiography revealed the drainer, which had been difficult to identify. The AVF disappeared after disconnection of the drainer. Case 2 involved a 68-year-old man presenting with severe headache due to SAH. DSA showed multiple AVFs at the CCJ and cerebellar tentorium. Intraarterial ICG videoangiography demonstrated concomitant perimedullary AVF and dural AVF at the CCJ. All AVFs disappeared postoperatively. LESSONS: Intraarterial ICG videoangiography was useful for definitive diagnosis of CCJ AVF, facilitating identification of feeders and drainers with bright and high phase contrast and allowing repeated testing to confirm flow direction.

Chronic subdural hematoma associated with dural metastasis leads to early recurrence and death: A single-institute, retrospective cohort study.

The prevalence of chronic subdural hematoma (CSDH) associated with dural metastasis is uncertain, and appropriate treatment strategies have not been established. This study aimed to investigate the characteristics of and appropriate treatment strategies for CSDH associated with dural metastasis. We retrospectively reviewed the charts of 214 patients who underwent surgery for CSDH. The patients were divided into the dural metastasis group (DMG; n = 5, 2.3%) and no dural metastasis group (No-DMG; n = 209, 97.3%). Patient characteristics, treatment, and outcomes were compared between the two groups. Active cancer was detected in 31 out of 214 patients, 5 of whom (16.1%) had dural metastasis. In-hospital death (80.0% vs. 0%; p < 0.001) and recurrence within 14 days (80.0% vs. 2.9%; p < 0.001) and 60 days (80.0% vs. 13.9%; p = 0.002) were significantly prevalent in the DMG. All patients in the DMG developed subdural hematoma re-accumulation requiring emergent surgery because of brain herniation, and patients in the DMG had significantly worse recurrence-free survival (p < 0.001). This relationship remained significant (p < 0.001) even when the analysis was limited to the active cancer cohort (n = 31). CSDH associated with dural metastasis leads to early recurrence and death because of the difficulty in controlling subdural hematoma re-accumulation by common drainage procedures. Depending on the primary cancer status, withdrawal of active treatment and change to palliative care should be discussed after diagnosing CSDH associated with dural metastasis.

Involvement of Neutrophil Extracellular Traps in Cerebral Arteriovenous Malformations.

BACKGROUND: Cerebral arteriovenous malformations (cAVMs) represent tangles of abnormal vasculature without intervening capillaries. High-pressure vascular channels due to abnormal arterial and venous shunts can lead to rupture. Multiple pathways are involved in the pathobiology of cAVMs including inflammation and genetic factors such as KRAS mutations. Neutrophil release of nuclear chromatin, known as neutrophil extracellular traps (NETs), plays a multifunctional role in infection, inflammation, thrombosis, intracranial aneurysms, and tumor progression. However, the relationship between NETs and the pathobiology of cAVMs remains unknown. We tested whether NETs play a role in the pathobiology of cAVMs. METHODS: We analyzed samples from patients who had undergone surgery for cAVM and immunohistochemically investigated expression of citrullinated histone H3 (CitH3) as a marker of NETs. CitH3 expression was compared among samples from cAVM patients, epilepsy patients, and normal human brain tissue. Expressions of thrombotic and inflammatory markers were also examined immunohistochemically in samples from cAVM patients. RESULTS: Expression of CitH3 derived from neutrophils was observed intravascularly in all cAVM samples but not other samples. Nidi of AVMs showed migration of many Iba-I-positive cells adjacent to the endothelium and endothelial COX2 expression, accompanied by expression of IL-6 and IL-8 in the endothelium and intravascular neutrophils. Unexpectedly, expression of CitH3 was not necessarily localized to the vascular wall and thrombus. CONCLUSIONS: Our results offer the first evidence of intravascular expression of NETs, which might be associated with vascular inflammation in cAVMs.

Efficacy of Intra-arterial Indocyanine Green Videoangiography in Hemangioblastoma Surgery: A Case Report.

Intravenous indocyanine green (ICG) videoangiography is reportedly useful for vascular neurosurgery, and for treating hemangioblastoma due to its high vascularity. Videoangiography obtained after intra-arterial ICG injection has emerged as a more useful option than that after intravenous injection. This report offers the first description of a case of hemangioblastoma successfully treated using intra-arterial ICG videoangiography, and describes the efficacy of this technique. A 20-year-old man presented with progressive cerebellar ataxia and dysphagia. Magnetic resonance imaging (MRI) revealed an enhanced solid tumor in the medulla oblongata. Digital subtraction angiography (DSA) showed a highly vascularized tumor. Surgery was performed to remove the tumor in a hybrid operating room. A catheter was introduced into the vertebral artery (VA) for intra-arterial ICG videoangiography. Superficial feeders and drainers were identified and flow dynamic changes in the tumor were assessed by intra-arterial ICG videoangiography. The tumor was removed after confirming lack of flow in the drainer. Intra-arterial ICG videoangiography was more useful than intravenous ICG videoangiography in hemangioblastoma surgery for identifying feeders and drainers and assessing flow dynamics in the tumor. Use of Flow 800 made these findings simpler and easier to evaluate.

Gelatin-thrombin Hemostatic Matrix-related Cyst Formation after Cerebral Hematoma Evacuation: A Report of Two Cases.

The gelatin-thrombin matrix, Floseal, is an excellent novel hemostatic agent that is used in various surgical fields. Thrombin is a serine protease, and the conversion of prothrombin to thrombin is an essential step in the coagulation cascade. However, thrombin can induce blood-brain barrier (BBB) disruption and vasogenic brain edema. This report describes two cases of gelatin-thrombin matrix-related cyst formation after cerebral hematoma evacuation. An 82-year-old man with a gelatin-thrombin matrix-related cyst was treated by cyst drainage and fenestration to the lateral ventricle. Histological evaluation of the cyst wall showed a gelatin-thrombin matrix reserve, marked infiltration of inflammatory cells, and foam cell accumulation. In addition, an 85-year-old woman with a gelatin-thrombin matrix-related cyst was treated with steroids and responded well. In both cases, the post-treatment course was uneventful. Cyst shrinkage and no recurrence were observed. The gelatin-thrombin matrix can cause cyst formation with brain edema. This is the first report demonstrating the cyst wall pathology and the steroid responsivity on cyst shrinkage. The mechanism of cyst formation is thought to be thrombin-induced BBB disruption. Excess gelatin-thrombin matrix should be carefully removed from the surgical beds, particularly those having a blinded space from the neurosurgical microscope.

High White Blood Cell Count Is a Risk Factor for Contrast-Induced Nephropathy following Mechanical Thrombectomy for Acute Ischemic Stroke.

BACKGROUND: Although mechanical thrombectomy is a standard endovascular therapy for patients with acute ischemic stroke (AIS), the incidence of and risk factors for contrast-induced nephropathy (CIN) following mechanical thrombectomy are infrequently reported. OBJECTIVES: The aim of this study was to investigate the incidence and risk factors for CIN following mechanical thrombectomy for AIS, and whether the incidence of CIN is related to a poor prognosis. METHODS: We examined consecutive patients who underwent a mechanical thrombectomy in the period from January 2014 to March 2018. The patients' clinical backgrounds, treatments, and clinical prognoses were analyzed. CIN was defined as an increase in the serum creatinine level of ≥44.2 µmol/L (0.5 mg/dL) or 25% above baseline within 72 h after exposure to the contrast medium. RESULTS: In total, 80 patients (46 men and 34 women aged 74.5 ± 11.5 years) who met our inclusion criteria were analyzed. CIN occurred in 8.8% (7/80) of the patients following mechanical thrombectomy. Although no patients needed permanent dialysis, 1 required temporary dialysis. The median amount of contrast medium was 109 mL. A comparison between the groups with and without CIN showed a significant difference in white blood cell (WBC) count at the time of admission (11.6 ± 2.7 × 103/µL and 8.1 ± 2.7 × 103/µL; p < 0.01) and the cut-off value was 9.70 × 103/µL. In multivariate analysis, contrast volume/estimated glomerular filtration rate by creatinine and WBC count were significantly associated with the incidence of CIN, with odds ratios of 1.64 (95% CI 1.02-2.65; p = 0.04) and 1.61 (95% CI 1.15-2.25; p < 0.01), respectively. CONCLUSIONS: This study found that CIN occurred in 8.8% of patients with AIS following mechanical thrombectomy. High WBC count was associated with an increased risk of CIN and may be helpful for predicting CIN.

Efficacy of intraarterial superselective indocyanine green videoangiography in cerebral arteriovenous malformation surgery in a hybrid operating room.

OBJECTIVE: Although intravenous indocyanine green (ICG) videoangiography has been reported to be useful when applied to cerebral arteriovenous malformation (AVM) surgery, the ICG that remains after the procedure makes it difficult to understand the anatomy, to evaluate nidus blood flow changes, and to repeat ICG videoangiography within a short time. Intraarterial ICG videoangiography has emerged as a way to overcome these limitations. The current study presents the results of intraarterial ICG videoangiography undertaken in patients with cerebral AVMs. METHODS: Intraarterial ICG videoangiography was performed in 13 patients with cerebral AVMs. Routine intraoperative digital subtraction angiography at the authors' institution is performed in a hybrid operating room during AVM surgery and includes the added step of injecting ICG to the contrast medium that is administered through a catheter. RESULTS: Predissection studies were able to visualize the feeder in 12 of 13 cases. The nidus was visualized in 12 of 13 cases, while the drainer was visualized in all cases. After total dissection of the nidus, there was no ICG filling in the drainers found in any of the cases. Washout of the ICG took 4.4 ± 1.3 seconds in the feeders, 9.2 ± 3.5 seconds in the drainers, and 20.9 ± 3.4 seconds in all of the vessels. Nidus flow reduction was confirmed during dissection in 9 of 9 cases. Flow reduction was easy to recognize due to each span being very short. Color-encoded visualization and objective data obtained by Flow 800 analysis reinforced these findings. CONCLUSIONS: The results showed that intraarterial ICG videoangiography was more useful than intravenous ICG videoangiography in cerebral AVM surgery. This was especially effective in the identification of the feeder, nidus, and drainer and in the assessment of the flow dynamics of the nidus. Use of Flow 800 made it simpler and easier to evaluate these findings.

[Pulsatile Tinnitus due to an Aberrant Internal Carotid Artery in the Middle Ear:A Case Report].

We report a rare case of aberrant internal carotid artery in the middle ear. The patient was a 30-year-old man with pulsatile tinnitus. MRA and 3D-CTA revealed an aberrant course of the internal carotid artery in the middle ear. 3D-CTA proved useful for radiographic diagnosis, leading to the observation of an aberrant internal carotid artery passing the foramen. We discuss the diagnosis and management of such patients.