A Case of Recurrence of Benign Convexity Primary Intraosseous Meningioma.

Meningiomas originating within the bones of the skull are rare and have been reported as primary intraosseous meningiomas (PIOM). Moreover, PIOMs with a skull base location or malignant pathology are predisposed to recurrence; however, recurrence is quite rare among PIOMs characterized by a convexity location and benign pathology. Here, we present a case of extensive recurrence of a convex intraosseous meningioma with benign pathology. A 72-year-old woman presented with a headache to our hospital. Gd contrast-enhanced magnetic resonance imaging revealed an enhanced tumor in the left frontal to the parietal region extending through the calvarial bone and invading the subdural space and subcutaneous tissue. Skull radiograph and computed tomography identified a remarkable osteolytic change in the lesion. Macroscopic complete resection (MCR) of the tumor and the surrounding tissues was performed. The tumor was histopathologically diagnosed as a transitional meningioma (World Health Organization grade 1). Seven years after the surgery, the patient presented with dysarthria, and the recurrence of the tumor was identified as massive lesions extending through the calvarial bone to the orbital bone, partially protruding into the brain and scalp. MCR was performed again, with the reconstruction of the skull for an extensive calvarial area using a titanium plate. This case is unique due to the extensiveness of the recurrent tumor and its rarity. Here, we report the details of the clinical course and discuss the characteristics of this case.

Efficacy of intraoperative irrigation with artificial cerebrospinal fluid in chronic subdural hematoma surgery: study protocol for a multicenter randomized controlled trial.

BACKGROUND: The surgical techniques for treatment of chronic subdural hematoma (CSDH), a common neurosurgical condition, have been discussed in a lot of clinical literature. However, the recurrence proportion after CSDH surgery remains high, ranging from 10 to 20%. The standard surgical procedure for CSDH involves a craniostomy to evacuate the hematoma, but irrigating the hematoma cavity during the procedure is debatable. The authors hypothesized that the choice of irrigation fluid might be a key factor affecting the outcomes of surgery. This multicenter randomized controlled trial aims to investigate whether intraoperative irrigation using artificial cerebrospinal fluid (ACF) followed by the placement of a subdural drain would yield superior results compared to the placement of a subdural drain alone for CSDH. METHODS: The study will be conducted across 19 neurosurgical departments in Japan. The 1186 eligible patients will be randomly allocated to two groups: irrigation using ACF or not. In either group, a subdural drain is to be placed for at least 12 h postoperatively. Similar to what was done in previous studies, we set the proportion of patients that meet the criteria for ipsilateral reoperation at 7% in the irrigation group and 12% in the non-irrigation group. The primary endpoint is the proportion of patients who meet the criteria for ipsilateral reoperation within 6 months of surgery (clinical worsening of symptoms and increased hematoma on imaging compared with the postoperative state). The secondary endpoints are the proportion of reoperations within 6 months, the proportion being stratified by preoperative hematoma architecture by computed tomography (CT) scan, neurological symptoms, patient condition, mortality at 6 months, complications associated with surgery, length of hospital stay from surgery to discharge, and time of the surgical procedure. DISCUSSION: We present the study protocol for a multicenter randomized controlled trial to investigate our hypothesis that intraoperative irrigation with ACF reduces the recurrence proportion after the removal of chronic subdural hematomas compared with no irrigation. TRIAL REGISTRATION: ClinicalTrials.gov jRCT1041220124. Registered on January 13, 2023.

Real-world data of clazosentan in combination therapy for aneurysmal subarachnoid hemorrhage: a multicenter retrospective cohort study.

Aneurysmal subarachnoid hemorrhage (aSAH) may lead to cerebral vasospasm, significantly associated with morbidity and mortality. In double-blind, placebo-controlled phase 3 studies, clazosentan reduces cerebral vasospasm-related morbidity and all-cause mortality in patients with aSAH. There are no reports about the clinical efficacy of clazosentan combination therapy with some other drugs. Initially, we explored the efficacy of clazosentan combination therapy with cilostazol, statin, and antiepileptic drugs. Subsequently, we assessed the add-on effect of fasudil to clazosentan combination therapy for aSAH patients. This multicenter, retrospective, observational cohort study included Japanese patients with aSAH between June 2022 and March 2023. The primary outcome was the ordinal score on the modified Rankin Scale (mRS; range, 0-6, with elevated scores indicating greater disability) at discharge. Among the 47 cases (women 74.5%; age 64.4 ± 15.0 years) undergoing clazosentan combination therapy, 29 (61.7%) resulted in favorable outcomes. Overall, vasospasm occurred in 16 cases (34.0%), with four cases (8.5%) developing vasospasm-related delayed cerebral ischemia (DCI). Both hypotension and vasospasm-related DCI were related to unfavorable outcome at discharge. Fasudil were added in 18 (38.3%) cases. Despite adding fasudil to clazosentan combination therapy, the incidence of aSAH-related vasospasm did not decrease. Added-on fasudil to combination therapy related to pulmonary edema, vasospasm, and vasospasm-related DCI, and unfavorable outcomes. Clazosentan combination therapy could potentially result in favorable outcomes for aSAH patients to prevent post-aSAH vasospasm-related DCI. The add-on effect of fasudil to combination therapy did not demonstrate a significant impact in reducing aSAH-related vasospasm or improving outcomes at discharge.

A Case of Primary Leptomeningeal Lymphoma Presenting with Hydrocephalus Characterized by Disproportionately Large Fourth Ventricle.

Primary leptomeningeal malignant lymphoma (PLML) is a rare variant of primary central nerve system malignant lymphoma (PCNSL) which is restricted to leptomeninges. The lesions of PLML can often be detected as abnormal enhancement on the surface of central nervous system or the ventricular wall on magnetic resonance imaging (MRIs). Cerebrospinal fluid (CSF) evaluation together with such MRI findings provides the definitive diagnosis of PLML. Here, we present a 45-year-old female case of PLML in which hydrocephalus with disproportionately large fourth ventricle was observed at presentation with gait instability. Head MRI revealed no abnormal enhancement and CSF cytology was negative, leaving the cause of hydrocephalus undetermined. Endoscopic third ventriculostomy (ETV) was effectively performed for hydrocephalus and her symptoms disappeared. Nearly 2 years later, she was brought to emergent room due to unconsciousness with the recurrence of hydrocephalus. MRI showed expanded fourth ventricle and abnormal enhancement on the ventricular wall. The endoscopic surgery for improving CSF flow was successful and inflammatory change was endoscopically observed on the ventricular wall involving aqueduct. Pathological diagnosis of the specimen from the ventricular wall proved B-cell lymphoma. Because neither brain parenchymal masses nor systemic tumors were identified, she was diagnosed with PLML and treated by high-dose methotrexate. She was in a stable state 2 years after the diagnosis of PLML. We report and discuss the characteristics of this case.

Malignant Glioma in the Cerebellum Presenting as Multiple Small Lesions.

Malignant glioma, the most common malignant primary brain tumor in adults, usually occurs in supratentorial space as a single mass lesion, and cerebellar location and multiple appearance are uncommon. We report a case of a 69-year-old female with three lesions simultaneously found in the cerebellum on magnetic resonance images (MRIs) after suffering from gait disturbance. Two lesions were around 15 mm in size and the other one was observed as a spotty enhancement. Although MRI findings suggested brain metastases, whole body examinations denied any primary malignancies. Biopsy for one lesion in the cerebellum was performed, which resulted in pathological diagnosis of malignant astrocytoma. The lesions were considered multicentric glioma based on MRI definition. The treatment with temozolomide and whole brain radiation was completed. Although the patient was discharged in an independent state with the shrinkage of the tumors, she unexpectedly died following sudden loss of consciousness from an unknown cause one month after discharge. The coincidence of cerebellar location and multicentricity characterized by smallness is quite rare in glioma patients, and such MRI findings might be misleading for the diagnosis. We describe the details of the case and discuss the pathogenesis of this unique presentation of malignant glioma with the literatures.

Long-Lasting Symptomatic Cerebral Hyperperfusion Syndrome following Superficial Temporal Artery-Middle Cerebral Artery Bypass in a Patient with Stenosis of Middle Cerebral Artery.

Cerebral hyperperfusion syndrome (CHPS) is a complication that can occur after cerebral revascularization surgeries such as superficial temporal artery- (STA-) middle cerebral artery (MCA) anastomosis, and it can lead to neurological deteriorations. CHPS is usually temporary and disappears within two weeks. The authors present a case in which speech disturbance due to CHPS lasted unexpectedly long and three months was taken for full recovery. A 40-year-old woman, with a history of medication of quetiapine, dopamine 2 receptor antagonist as an antipsychotics for depression, underwent STA-MCA anastomosis for symptomatic left MCA stenosis. On the second day after surgery, the patient exhibited mild speech disturbance which deteriorated into complete motor aphasia and persisted for one month. SPECT showed the increase of cerebral blood flow (CBF) in left cerebrum, verifying the diagnosis of CHPS. Although CBF increase disappeared one month after surgery, speech disturbance continued for additionally two months with a slow improvement. This case represents a rare clinical course of CHPS. The presumable mechanisms of the prolongation of CHPS are discussed, and the medication of quetiapine might be one possible cause by its effect on cerebral vessels as dopamine 2 receptor antagonist, posing the caution against antipsychotics in cerebrovascular surgeries.

Effectiveness of Goreisan in Preventing Recurrence of Chronic Subdural Hematoma.

BACKGROUND: Burr-hole irrigation surgery is now recognized as a widespread simple technique for the treatment of chronic subdural hematoma (CSDH). However, recurrence of CSDH is sometimes experienced after initial surgery. Recently, it has been reported that goreisan is effective in preventing CSDH recurrence. MATERIALS AND METHODS: Methods: We studied patients with CSDH who received burr-hole irrigation at our hospital between January 2011 and December 2014. We divided these patients into three groups. The first group was given goreisan during the early phase after burr-hole irrigation. The second group was given goreisan when there was a visual tendency of recurrence, as observed in the course of computed tomography imaging for outpatients. The third group was not given any drug. RESULTS: The recurrence rate was compared between each group. The recurrence rate was significantly lower in the early goreisan administration group (5% vs. 12%, P = 0.046). There was a decreased tendency of recurrence in the goreisan-administered group compared with the group that was not administered any drug, but this was not statistically different (6.1% vs. 12%, P = 0.082). The recurrence period in the goreisan-administered group was longer than that in the group that was not administered any drug (39.9 ± 12.1 vs. 27.45 ± 8.5, P = 0.017). CONCLUSIONS: Goreisan is effective in preventing recurrence of CSDH after burr-hole irrigation.

Independent Anomalous Origin of the Right Vertebral Artery from the Right Common Carotid Artery.

An anomalous origin of the right vertebral artery is rare. The left vertebral artery from the aortic arch is where most of the anomalies occur. The next is an origin of the right vertebral artery from the right common carotid artery in association with the aberrant right subclavian artery. However, independent anomalous origin of the right vertebral artery from the right common carotid artery has not been well known in the previous literature. We present this anomaly, and able to understand the mechanism of the occurrence by embryological knowledge. Failure of involution of the fourth segmental artery and the ductus caroticus remaining are associated with this anomaly. To understand this, an aberrant may be helpful to avoid injury of the vertebral artery when performing the surgical procedures and catheterization.

A Stent-Retrieving into an Aspiration Catheter with Proximal Balloon (ASAP) Technique: A Technique of Mechanical Thrombectomy.

OBJECTIVE: The best technique for the first attempt at mechanical thrombectomy for acute ischemic stroke is a still matter of debate. In this study, we evaluate the efficacy of a stent-retrieving into an aspiration catheter with proximal balloon (ASAP) technique that uses a series of thrombus extraction by withdrawing the stent retriever into the aspiration catheter and continuous aspiration from the aspiration catheter at the first attempt. METHODS: We performed a retrospective analysis of 42 consecutive patients with acute ischemic stroke caused by occlusions in the anterior circulation who were treated with the ASAP technique at our institution. Preoperative patient characteristic, including age, thrombus location, Alberta Stroke Program Early CT Score, National Institutions of Health Stroke Scale, and time from onset to puncture; postoperative Thrombolysis in Cerebral Infarction score; modified Rankin Scale score after 3 months; time from puncture to recanalization; the number of passes to achieve recanalization; and procedural complications, including intracranial hemorrhage, embolization to new territory, and distal embolization, were assessed. RESULTS: A Thrombolysis in Cerebral Infarction score of 2B or 3 was achieved in 40/42 patients (95.2%). Average time from puncture to the final recanalization was 21.5 minutes. Recanalization was achieved in a single attempt in 31 patients (77.5%). Embolization to new territory was observed in only 2 patients (4.8%); no patient developed distal embolization or intracranial hemorrhage including asymptomatic subarachnoid hemorrhage. Thirty-two patients (76.2%) achieved modified Rankin Scale scores of 0-2 at 3 months postoperatively. CONCLUSIONS: Our ASAP technique showed fast recanalization, minimal complications, and good clinical outcomes in this case series.

Crevice sign as an indicator of plaque laceration associated with postoperative severe thromboembolism after carotid artery stenting: a case report.

Carotid artery stenting (CAS) is increasingly utilized in patients with carotid artery stenosis. Various intraprocedural and postprocedural complications have been reported in the literature. We present a case of symptomatic major thromboembolism after CAS. The intraprocedural angiogram showed extraordinary slow filling of the contrast medium into the plaque, which we named as "crevice sign." An 83-year-old man presented repeat right amaurosis fugax for 6 months. The radiological examinations revealed 85% stenosis of the origin of the right internal carotid artery. The patient underwent right CAS. The procedure was performed without any problems; however, the angiogram showed slow filling of contrast medium into the carotid plaque through the stent (crevice sign). Sixty minutes later in the ward, the patient presented sudden onset of left hemiparesis and aphasia. Emergency catheter angiography did not show in-stent thrombus, major artery occlusion, or the crevice sign. Magnetic resonance imaging on the next day revealed wide acute infarction of the right cerebral hemisphere. Physicians should be aware of the intraprocedural crevice sign so that a subsequent catastrophic ischemic event can be prevented.

A Case of Acute Isolated Posterior Cerebral Artery Occlusion Successfully Treated with Endovascular Clot Aspiration.

Posterior cerebral artery (PCA) strokes produce various symptoms. Therefore, the diagnosis is often delayed and patients arrive late for thrombolytic therapy. We report a case of acute isolated PCA occlusion that was successfully treated with endovascular clot aspiration. A 63-year-old man presented with right complete homonymous hemianopia. Diffusion-weighted image (DWI) showed a high-intensity area (HIA) in the occipital lobe, and magnetic resonance angiography (MRA) showed PCA occlusion. Emergency endovascular clot aspiration was performed immediately after the diagnosis. Blood flow in PCA completely recovered 210 min after symptom onset. DWI after surgery showed partial disappearance of HIA, and the patient recovered from the symptom of right complete homonymous hemianopia. Endovascular recanalization is useful for acute PCA occlusion. This is the first reported case of acute isolated PCA occlusion successfully treated with endovascular clot aspiration. Prompt reperfusion results in a good clinical course in patients with PCA stroke. In this case, endovascular clot aspiration resulted in prompt recanalization in a patient with acute isolated PCA occlusion.

Suitability of a 7-F ExoSeal Vascular Closure Device for Femoral Artery Punctures Made by 8-F or 9-F Introducer Sheaths.

PURPOSE: To establish the safety and efficacy of the 7-F ExoSeal device for the closure of femoral puncture sites made by 8-F or 9-F introducer sheaths. METHODS: Between January 2013 and December 2016, 332 patients (mean age 68.4±12.1 years; 195 men) underwent neurointerventional procedures via percutaneous puncture of the common femoral artery and an 8-F (n=272, 81.9%) or 9-F (n=60, 18.1%) introducer. The access sites were sealed with a 7-F ExoSeal in all cases. Procedure success and closure-related complication rates were evaluated, and risk factors for complications were analyzed by comparing patient characteristics between those who did and did not experience complications. RESULTS: Procedure success rates were 99.3% in the 8-F group and 100% in the 9-F group. The overall complication rate was 6.3% (n=17; all in the 8-F group), of which 13 (4.8%) were minor sequelae, including access-site hematoma (n=8), oozing (n=3), pseudoaneurysm (n=1), and retroperitoneal bleeding (n=1). Among the 4 (1.5%) major complications were 3 instances of bleeding requiring a blood transfusion and 1 surgical vascular repair. No complications were observed in the 9-F group. Patients who experienced complications had significantly longer activated clotting times (262±46 vs 218±55 seconds; p<0.001) compared with patients without complications. CONCLUSION: A 7-F ExoSeal vascular closure device is safe and effective for the closure of femoral puncture sites made by 8-F or 9-F introducer sheaths.

Treatment protocol based on assessment of clot quality during endovascular thrombectomy for acute ischemic stroke using the Trevo stent retriever.

The optional endovascular approach for acute ischemic stroke is unclear. The Trevo stent retriever can be used as first-line treatment for fast mechanical recanalization. The authors developed a treatment protocol for acute ischemic stroke based on the assessment of clot quality during clot removal with the Trevo. This prospective single-center study included all patients admitted for acute ischemic stroke between July 2014 and February 2015, who underwent emergency endovascular treatment. According to the protocol, the Trevo was used for first-line treatment. Immediately after the Trevo was deployed, the stent delivery wire was pushed to open the stent by force (ACAPT technique). Clot quality was assessed on the basis of the perfusion status after deployment of the Trevo; continued occlusion or immediate reopening either reoccluded or maintained after the stent retriever had been in place for 5 min. If there was no obvious clot removal after the first pass with the Trevo, according to the quality of the clot, either a second pass was performed or another endovascular device was selected. Twelve consecutive patients with acute major cerebral artery occlusion were analyzed. Thrombolysis in cerebral infarction score 2b and 3 was achieved in 11 patients (91.7%) and 9 (75%) had a good clinical outcome after 90 days based on a modified Rankin scale score ≤ 2. Symptomatic intracranial hemorrhage occurred in 1 patient (8.3%). The overall mortality rate was 8.3%. Endovascular thrombectomy using the Trevo stent retriever for first-line treatment is feasible and effective.

[A Novel, Less Invasive Protection Method for Carotid Artery Stenting].

Purpose: We present a novel, less invasive protection method for carotid artery stenting. Case presentation: A 67-year-old man presented with symptomatic severe left carotid artery stenosis. A transfemoral approach was dangerous because of an abdominal aortic aneurysm. A 6Fr Axcelguide Simmonds catheter was inserted into the right brachial artery, and advanced into the left common carotid artery. Next, a 6Fr Optimo 100-cm catheter was coaxially navigated into the left common carotid artery. A PercuSurge GuardWire 300-cm was coaxially navigated into the left external carotid artery. Under flow reversal with the 2 balloons, another PercuSurge GuardWire 300-cm was navigated into the distal left internal carotid artery through the lesion. After both PercuSurge GuardWire balloons were inflated, the 6Fr Optimo was deflated and retrieved using a catheter exchange technique. Then, under distal double-balloon protection, routine stenting was performed. Conclusions: This technique is safer and less invasive than previous methods, especially in cases with difficult femoral access and vulnerable carotid plaque.

Overlap stenting for in-stent restenosis after carotid artery stenting.

Our aim was to assess the clinical safety and efficacy of overlap stenting for in-stent restenosis after carotid artery stenting. The study was conducted between July 2008 and February 2015. A database of consecutive carotid artery stenting procedures was retrospectively assessed to identify the cases of in-stent restenosis that were treated with overlap stenting under proximal or distal protection. The clinical and radiological records of the patients were then reviewed. Of the 155 CAS procedures in 149 patients from the database, 6 patients met the inclusion criteria. All the 6 patients were initially treated with moderate dilatation because of the presence of an unstable plaque. The technical success rate of the overlap stenting was 100%, with no 30-day mortality or morbidity. In addition, there was no further in-stent restenosis during a follow-up period of over 12 months. These results indicated that overlap stenting for in-stent restenosis after carotid artery stenting was both safe and effective in our cohort.

Successful steroid treatment of coma induced by severe spontaneous intracranial hypotension.

Spontaneous intracranial hypotension (SIH) is a syndrome characterized by low cerebrospinal fluid (CSF) pressure and postural headaches. It is a rare condition which may sometimes present with severe symptoms such as stupor or coma. The standard treatment protocol includes conservative measures such as bed rest, hydration, and steroids. However, severe cases may require invasive measures such as epidural blood patch (EBP), continuous epidural saline infusion, epidural fibrin glue, or surgical repair of the dural defect. In this report, we describe a case of severe SIH resulting in coma that exhibited dramatic improvement on intravenous administration of steroids. This is the first report of severe SIH causing coma that was treated non-invasively by steroids only.

Patterns of Recurrence After Resection of Malignant Gliomas With BCNU Wafer Implants: Retrospective Review in a Single Institution.

BACKGROUND: Bis-chloroethylnitrosourea (BCNU) wafers have been demonstrated to be effective for prolonging survival for patients with malignant glioma and have been approved worldwide. BCNU wafers are implantable and have a unique feature of delivering chemotherapeutic drug at high concentration at tumor margin over time after resection. BCNU wafers presumably, by this mechanistic rationale, have a beneficial effect on local tumor control and thus could change the pattern of recurrence, which is most frequently local. However, no studies have demonstrated such phenomenon after BCNU wafer implants. METHODS: To investigate whether the surgeries with BCNU wafers alter the predominant tendency of local recurrence pattern, we retrospectively reviewed 8 malignant glioma patients treated with BCNU wafers (BCNU wafer group), together with 22 glioma patients who did not receive BCNU wafers (no-BCNU wafer group) for comparison. RESULTS: Out of 6 patients in BCNU wafer group who exhibited recurrence, 1 showed local, 2 showed diffuse, and 3 showed a distant recurrence pattern, which was away from resection cavity. On the other hand, out of 18 patients in the no-BCNU wafer group who exhibited recurrence, 10 showed a local pattern, 8 showed a diffuse pattern, and no cases showed distant pattern. Distant pattern was observed significantly more frequently in the BCNU wafer group than in the no-BCNU wafer group. CONCLUSIONS: These results suggest that BCNU wafers could have a beneficial effect on local tumor control and may provide BCNU wafers with a new profile that could be considered for establishing future chemotherapeutic strategy for glioma patients.

Successful Preoperative Endovascular Embolization of an Extreme Hypervascular Glioblastoma Mimicking an Arteriovenous Malformation.

BACKGROUND: Preoperative endovascular embolization as a treatment for hypervascular glioblastomas has not been established. We report the case of an extreme hypervascular glioblastoma mimicking an arteriovenous malformation that was successfully treated with preoperative embolization and subsequent removal. CASE DESCRIPTION: A 66-year-old man presented with progressive right hemiparesis and sensory aphasia. Cranial computed tomography and magnetic resonance imaging revealed a left parietooccipital tumor with ring enhancement. Digital subtraction angiography revealed an extreme high-flow arteriovenous shunt. The patient underwent presurgical endovascular embolization using N-butyl cyanoacrylate in a manner similar to embolization for arteriovenous malformations. Subsequent tumor removal was achieved with minimal blood loss. CONCLUSIONS: This is the first reported case of presurgical embolization of a glioblastoma with a high-flow shunt. Embolization of a malignant tumor with a high-flow shunt, in a manner similar to embolization of arteriovenous malformations, is feasible and effective.

Preoperative embolization of meningiomas with low-concentration n-butyl cyanoacrylate.

The aim of this study was to determine the clinical safety and efficacy of preoperative embolization of meningiomas with low-concentration n-butyl cyanoacrylate (NBCA). Nineteen cases of hypervascular intracranial meningiomas were treated by preoperative embolization with 14% NBCA, using a wedged superselective catheterization of feeding arteries and reflux-hold-reinjection technique. Clinical data of the patients and radiological and intra-surgical findings were reviewed. All tumors were successfully devascularized without any neurological complications. Marked reduction of tumor staining with extensive NBCA penetration was achieved in 13 cases. Perioperative blood transfusion was only required in two cases. These results indicate that preoperative embolization of meningiomas with low-concentration NBCA is both safe and effective.

[A Case of Cavernous Sinus Dural Arteriovenous Fistula after Transverse-Sigmoid Sinus Dural Arteriovenous Fistula Treatment with Radical Transvenous Coil Embolization].

PURPOSE: We report a case of cavernous sinus dural arteriovenous fistula (dAVF) that developed after the treatment of a transverse-sigmoid sinus dAVF using transvenous embolization (TVE). CASE PRESENTATION: A 72-year-old woman presented with headache and left-sided tinnitus. Angiography demonstrated the presence of a left transverse-sigmoid sinus dAVF. After TVE, the patient's symptoms completely disappeared. Three years later, she complained of left-sided tinnitus and diplopia, and angiography revealed the presence of a left cavernous sinus dAVF. We performed transvenous coil embolization, and the dAVF disappeared. CONCLUSIONS: TVE has been widely recognized as an effective treatment for dAVF. However, dAVF may develop at a different location after TVE in a few cases. A long-term follow-up is therefore recommended.