The absence of safe and reliable methods to harvest vascular tissue in situ limits the discovery of the underlying genetic and pathophysiological mechanisms of many vascular disorders such as aneurysms. We investigated the feasibility and comparable efficacy of endothelial cell collection using a spectrum of endovascular coils.
Nine detachable coils ranging in k coefficient (0.15-0.24), diameter (4.0 mm-16.0 mm), and length (8.0 cm-47.0 cm) were tested in pigs. All coils were deployed and retrieved within the iliac artery of pigs (three coils/pig). Collected coils were evaluated under light microscopy. The total and endothelial cells collected by each coil were quantified. The nucleated cells were identified by Wright-Giemsa and DAPI stains. Endothelial and smooth muscle cells were identified by CD31 and α-smooth muscle actin antibody staining.
Coils were deployed and retrieved without technical difficulty. Light microscopy demonstrated sheets of cellular material concentrated within the coil winds. All coils collected cellular material while five of nine (55.6%) coils retrieved endothelial cells. Coils collected mean endothelial cell counts of 89.0±101.6. Regression analysis demonstrated a positive correlation between increasing coil diameter and endothelial cell counts (R2=0.52, p = 0.029).
Conventional detachable coils can be used to harvest endothelial cells. The number of endothelial cells collected by a coil positively correlated with its diameter. Given the widespread use of coils and their well-described safety profile their potential as an endovascular biopsy device would expand the availability of tissue for cellular and molecular analysis.
endothelial; endovascular; aneurysm; brain; stroke; biopsy
This study investigated the feasibility of using intra-arterial injection-based cerebral blood volume (CBV) imaging with flat detector computed tomography (CT, IAFD-CBV). It is proven that this new method could provide comparable physiologic information as standard intravenous injection-based multi-slice computed tomography CBV imaging (IVCT-CBV).
Twelve patients were examined using both IAFD-CBV and IVCT-CBV. An experienced neuroradiologist read both sets of generated CBV maps. If a physiologic perfusion disorder was detected in standard IVCT-CBV, the focus was to check whether IAFD-CBV indicated the same disorder or not. Otherwise, if no disorder was detected, relative CBV (rCBV) values at different basal ganglia regions were measured for both CBV maps and then compared.
For three patients with lesions, IAFD-CBV and IVCT-CBV showed similar perfusion disorders in the corresponding regions. For nine patients without lesions, both CBV maps showed good symmetry of contrast agent (CA) distribution for left/right hemisphere, the total average of rCBV was found to be 0.94 −/+0.18 and 1.01 −/+0.14 (1.0 for perfect symmetry) in IAFD-CBV and IVCT-CBV, respectively. However, compared to IVCT-CBV, IAFD-CBV imaging required 70% less contrast agent (CA).
In general, a good correlation between IAFD-CBV and IVCT-CBV was found for all 12 patients. Minor deviations of IAFD-CBV were only detected at regions supplied by the middle cerebral artery. IAFD-CBV imaging, which can be directly performed in a catheterization laboratory, was proven to be technically feasible for real-time CBV assessment of the whole brain with good accuracy, and minimized CA usage.
flat detector CT; cerebral blood volume; perfusion
The Solitaire system has recently been increasingly used for acute stroke treatment in which the endothelial safety immediately after its use has not been evaluated. This study was performed to evaluate the endothelial status when using a Solitaire system in a canine arterial occlusion model.
Thromboembolic occlusion of both internal maxillary arteries was achieved in five mongrel dogs. In each animal, the Solitaire system (ev3, Irvine, CA, USA) was used for primary thrombectomy on the right side and for temporary stenting on the left side. Efficacy was assessed by comparing the recanalization rates, and safety was assessed using angiographic and microscopic assessments. Endothelial injuries were evaluated with light microscopy (LM) and scanning electron microscopy (SEM).
Successful revascularizations were observed following primary thrombectomy in all five animals (100%) and after temporary stenting in two (40%). There was no incidence of vasospasm or vessel perforation in either group. Distal migration of the clot occurred in two animals that underwent primary thrombectomy. Endothelial injury was seen after primary thrombectomy in two animals (40%) and after temporary stenting in one (20%). The lesions presented as defects of the internal elastic lamina on LM and denudation of the wavy endothelial surface on SEM.
During mechanical thrombectomy, the Solitaire system can cause endothelial injury both in primary thrombectomy and temporary stenting. Primary thrombectomy is likely to have a higher recanalization rate with increased endothelial injury.
stroke; thrombectomy; stents; animal model; endothelium
Cervical transforaminal epidural injections (C-TfEI) are commonly performed in patients with cervical radiculopathy/pain. C-TfEIs are typically performed without incident but adverse events can occur. Using CT-fluoroscopy-guided C-TfEI, we commonly observe the vertebral artery in proximity to the target injection site. The purpose of this study was to assess the position of the vertebral artery relative to the typical C-TfEI injection point.
CT-fluoroscopy-guided C-TfEIs were performed at 70 levels in 68 patients with radiculopathy/neck pain (age range 19-83 yrs, mean 50.6 yrs). Degenerative neural foraminal narrowing at each level was characterized (normal-to-mild, moderate, severe). Vertebral artery position was categorized as: anterior (normal), partially covering neural foramen, complete/near-complete covering the neural foramen. Additional measured variables included angle of needle trajectory, foraminal angle, and whether or not needle trajectory intersected with the vertebral artery.
Foraminal vertebral artery covering correlated with severity of foraminal degenerative narrowing (p=0.003). Complete/near-complete covering was seen in: 65% severely narrowed foramina, 30% moderately narrowed foramina and 10% normal/mildly-narrowed foramina. Needle trajectory intersected with the vertebral artery in 30 of 70 injections (46%) by CT-fluoroscopy, frequently associated with shallow (lateral) approaches. Foraminal angle, approximating oblique fluoroscopic technique, suggests needle trajectory intersection with the vertebral artery in 27 of 70 foramina (39%).
Vertebral artery position is commonly displaced into the foramen in patients with advanced cervical degenerative disease. Operator awareness of altered vertebral artery position is important for determination of optimal needle trajectory and tip placement prior to injection in patients undergoing C-TfEI.
cervical spine; cervical radiculopathy; neck pain; cervical transforaminal epidural injection; cervical nerve root block; computed tomography
Flow diverters (FDs) are increasingly used for complex intracranial aneurysms. As these self-expanding devices are deployed across an aneurysm neck, they can undergo deformations. The potential clinical consequences of FD deformations remain unclear.
We describe an immediate thrombotic complication attributed to a stereotypical stenotic deformation of an FD extremity that can occur when landing zones are of insufficient length. This case is supplemented with in vitro studies showing the relationship between i) the length of the landing zones and ii) discrepancies between the diameter of the device and recipient vessel, and the severity of FD stenosis.
In vitro, a shorter landing zone was associated with a progressive stenotic deformation of the terminal ends of all FDs studied. This deformation was more pronounced when the diameter of the device was oversized compared to the size of the recipient tube. In our clinical case, the presence of this deformation led to an immediate thrombotic complication, requiring deployment of a second stent to correct the observed stenosis. In addition, treatment failure ultimately led to a fatal rupture, a failure that can be explained by residual flows through a more porous transition zone, another characteristic FD deformation which occurs when they are oversized as compared to the parent vessel, but free to expand at the level of the aneurysm.
Proper selection of device diameter and length of the landing zone is important, and may decrease the incidence of deformation-related complications.
flow diverter; aneurysm; complication; in-stent stenosis
This study determined the utility and accuracy of susceptibility-weighted MRI (SWI) for the detection of carotid cavernous fistulas.
We retrospectively compared SWI images in nine patients (Group 1, case group) of DSA-proved carotid cavernous fistula (CCF) and 19 DSA negative cases for CCF as a control group (Group 2). Group 1 was again sub-grouped into direct and indirect types. Using uniform region-of-interest measurements, signal intensity within the superior ophthalmic vein (SOV) and the superior sagittal sinus (SSS) were measured on magnitude images of SWI. The SOV/SSS signal intensity ratio was calculated in each case and the mean values of the two groups were compared.
Eleven SOV/SSS signal intensity ratios in Group 1 (7 unilateral and two bilateral CCF), 38 in Group 2 (both sides in 19 control subjects) were included. Median ± interquartile range of SOV/SSS ratios for Group 1, Group 2, indirect and direct type CCFs were 1.07 ± 0.43, 0.39 ± 0.23, 0.83 ±0.29, 1.4 ±0.38 respectively. Mann-Whitney test between Groups 1 and 2 was statistically significant with P<0.0001. All cases and controls were reliably distinguished with SOV/SSS signal intensity ratio of 0.64 as cut-off. Direct CCF cases had consistently higher ratios than indirect CCF. SWI was highly sensitive for detection and differentiation of both direct and indirect CCF. Only one case of corticovenous reflux was missed by SWI.
SWI is useful for detection of CCF and to differentiate between direct and indirect CCF.
carotico-cavernous fistula; susceptibility-weighted imaging; magnetic resonance imaging
This study aimed to propose an alternative treatment for carotid cavernous fistula (CCF) using the balloon-assisted sinus coiling (BASC) technique and to describe this procedure in detail.
Under general anesthesia, we performed the BASC procedure to treat five patients with traumatic CCF. Percutaneous access was obtained via the right femoral artery, and a 7F sheath was inserted, or alternatively, a bifemoral 6F approach was accomplished. A microcatheter was inserted into the cavernous sinus over a 0.014-inch microwire through the fistulous point; the microcatheter was placed distal from the fistula point, and a “U-turn” maneuver was performed. Through the same carotid access, a compliant balloon was advanced to cross the point of the fistula and cover the whole carotid tear. Large coils were inserted using the microcatheter in the cavernous sinus. Coils filled the adjacent cavernous sinus, respecting the balloon.
Immediate complete angiographic resolution was achieved, and an early angiographic control (mean = 2.6 months) indicated complete stability without recanalization. The clinical follow-up has been uneventful without any recurrence (mean = 15.2 months).
An endovascular approach is optimal for direct CCF. Because the detachable balloon has been withdrawn from the market, covered stenting requires antiplatelet therapy and its patency is unconfirmed, but cavernous sinus coiling remains an excellent treatment option. Currently, there is no detailed description of the BASC procedure. We provide detailed angiograms with suitable descriptions of the exact fistula point, and venous drainage pathways. Familiarity with these devices makes this technique effective, easy and safe.
trauma; carotid artery; cavernous sinus fistula; endovascular treatment; embolization
Y-stent placement to treat bifurcation aneurysms requires the second device to cross the confines of the first stent, with concerns regarding the formation of stenosis of the second device at the site of crossing.
Various braided stents and flow diverters (FDs) were deployed to cross through a high porosity braided stent, in a Y configuration, with the ends of the devices inserted in plastic tubes of various diameters, leaving the mid-portion free to expand. The ensuing constructs were photographed, paying attention to the degree of stenosis, if any, created where the second device crosses the first stent. Experiments were repeated selecting different zones of the first stent as the site of crossing for the second device, different tube diameters, and changing the angle of the bifurcation.
Crossing the first stent did not cause the second stent to become significantly stenosed in any case. Crossing through the transition or expansion zone of the first device had no influence on results. Different bifurcation angles had no influence on the occurrence of stenosis.
Y-stent placement to treat arterial bifurcations using braided self-expanding stents and FDs does not lead to significant stenosis in bench-top studies.
flow diverters; stent; stenosis; bench studies
Fenestration of the basilar artery (BA) is a rare variant of the intracranial artery, well demonstrated in autopsy and angiographic studies. Some angiographic series show a high incidence of associated aneurysms at the basilar fenestration site. The purpose of this study is to report the incidence of BA fenestration, its configurations, associated aneurysms, and arterial anomalies in a large series of intracranial MR angiograms (MRAs).
A total of 16,416 MRAs were retrospectively reviewed to identify the location, size and associated intracranial arterial anomalies of BA fenestrations. All images were obtained with the time-of-flight (TOF) technique. Of the 16,416 MRAs, 215 fenestrations were found in 212 cases (1.29%). Most fenestrations were located in the proximal BA. The average length of the fenestration was 4.6 mm; the largest was 15.6 mm. No aneurysm was found at the site of the fenestration. Thirteen aneurysms were found in nine cases at locations other than the BA: seven in the middle cerebral artery (MCA), one in the anterior cerebral artery (ACA), one in the anterior communicating artery (Acom), one in the vertebral artery (VA), one at the carotid siphon, and two at the internal carotid-posterior communicating artery (IC-PC). Arterial anomalies in other locations were found in 26 cases.
BA fenestrations were found in 1.29% of the 16,416 cases studied. There were no aneurysms at the BA fenestration site. Aneurysms at the BA fenestration site may be an exceedingly rare phenomenon.
basilar artery; fenestration; MR angiography; normal variant
Intracranial hemangiopericytomas are uncommon but highly vascular dural-based tumors which commonly derive arterial blood supply from both intracranial and extracranial circulations. Microsurgical resection of these lesions may result in excessive blood loss without the aid of pre-operative embolization. We describe a case of a large tentorial hemangiopericytoma for which initial resection was aborted due to excessive blood loss. After failed endovascular access, we performed a direct transcranial puncture of the hemangiopericytoma through the craniotomy defect and successfully embolized the tumor with Onyx. Post-embolization gross total resection was achieved with a limited amount of operative blood loss. Direct puncture embolization provides several advantages over traditional endovascular embolization including decreased procedural duration, circumventing challenging arterial anatomy, and a lower risk of stroke in the presence of extracranial-to-intracranial anastamoses. While direct puncture embolization has been described for tumors of the neck and skull base, this is the first reported case of an intracranial hemangiopericytoma successfully devascularized by direct transcranial puncture Onyx embolization.
hemangiopericytoma; therapeutic embolization; endovascular procedures; Onyx copolymer; brain neoplasms
Blood blister-like aneurysms (BLAs) are rare lesions, associated with diffuse subarachnoid hemorrhage (SAH). BLAs tend to rebleed quickly after first bleeding and must be treated as an emergency. Acute treatment is challenging using surgical and endovascular approaches due to the fragile aneurysm wall and small sac. Flow-diverter stents (FDSs) may offer a new option for the treatment of difficult small aneurysms. We describe a case of a ruptured BLA on the anterior communicating artery (AComA) treated in the acute phase of SAH by endovascular exclusion of the AComA with deployment of two FDSs in the A1/A2 junctions of both anterior cerebral arteries (ACAs). A 61-year-old man was admitted for diffuse SAH with a focal interhemispheric hematoma. Angiography revealed multiple arterial wall irregularities on the AComA and both ACAs. We performed an endovascular shunt of the AComA by deploying two FDSs in both A1/A2 junctions. Immediate control injections confirmed flow diversion in the A1/A2 segments of the ACAs with decreased blood flow in the AComA. The patient's course in hospital was uneventful. A three-month follow-up angiogram confirmed complete exclusion of the aneurysms, complete exclusion of the AComA, and patency of the two ACAs without any persistent arterial wall irregularity. Endovascular bypass using an FDS for a ruptured BLA has never been described. It establishes a new therapeutic option despite the need for antiplatelet therapy. Endovascular AComA exclusion using an FDS may be a solution when no other treatment is available for a ruptured BLA.
blister-like aneurysm; flow-diverter stent; subarachnoid hemorrhage
Conventional endovascular treatment may have limitations for vertebral dissecting aneurysm involving the origin of the posterior inferior cerebellar artery (PICA). We report our experiences of treating vertebral dissecting aneurysm with PICA origin involvement by placing a stent from the distal vertebral artery (VA) to the PICA to save the patency of the PICA.
Stenting from the distal VA to the PICA was attempted to treat ruptured VA dissecting aneurysm involving the PICA origin with sufficient contralateral VA in eight patients.
The procedure was successfully performed in seven patients with one failure because of PICA origin stenosis, which was treated with two overlapping stents. In the seven patients, PICAs had good patency on postoperative angiography and transient lateral brainstem ischemia represents a procedure-related complication. Follow-up angiographies were performed in seven patients and showed recanalization of the distal VA in three patients without evidence of aneurysmal filling. There was no evidence of aneurysm rupture during the follow-up period, and eight patients had favorable outcomes (mRS, 0 - 1).
Placing a stent from the distal VA to the PICA with VA occlusion may present an alternative to conventional endovascular treatment for vertebral dissecting aneurysm with PICA origin involvement with sufficient contralateral VA.
vertebral artery; posterior inferior cerebellar artery; stent; dissecting aneurysm
We describe a unique case of bilateral cervical spinal dural arteriovenous fistulas mimicking an intracranial dural arteriovenous fistula near the foramen magnum. We review its detection via MRI and digital subtraction angiography and subsequent management through surgical intervention. Pitfalls in diagnostic angiography are discussed with reference to accurate location of the fistula site. The venous anastomotic connections of the posterior midline spinal vein to the medial posterior medullary vein, posterior fossa bridging veins, and dural venous sinuses of the skull base are discussed with reference to problem-solving in this complex case. The mechanism of myelopathy through venous hypertension produced by spinal dural fistulas is also emphasized.
spinal dural arteriovenous fistula; digital subtraction angiography; MR angiography; MR imaging; vascular malformations; spine; spinal angiography
This study reports the differences in evolution and course of multiple pseudoaneurysms (PAs) and an axillary arteriovenous fistula (AVF) after penetrating vascular trauma due to shotgun injury to the head and neck.
We describe the unusual case of a young man who, following penetrating shotgun injuries to the head and neck, developed multiple PAs of the common carotid, vertebral and superficial temporal arteries as well as an axillary AVF. Serial angiographic follow-up studies documented differences in time of occurrence, evolution and course of these lesions. This allowed for tailored management using endovascular (AVF, superficial temporal artery PAs) and conservative (carotid and vertebral PAs) treatment. No complication occurred and complete cure of all lesions was achieved and documented after seven months.
Time of occurrence, evolution and regression of penetrating vascular injuries can differ significantly even in the same patient. Close angiographic follow-up helps not only detect a lesion with delayed occurrence, but also provides a practical basis for decision-making for optimal therapeutic management.
gunshot injury; pseudoaneurysm; arteriovenous fistula; endovascular treatment; conservative management
Traumatic brachial plexus complete avulsions and the subsequent formation of pseudomeningoceles are a well-known entity that usually remains asymptomatic. Pseudomeningocele is due to the dural sleeve encasing the damaged roots and the spinal liquid that may accumulate locally or in the supraclavicular soft tissues. The pseudomeningocele, added to the associated lesion of the plexus and usually the surrounding vessels, may become difficult to manage. We describe the novel management of a traumatic pseudomeningocele using an endovascular technique.
root avulsion; pseudomeningocele; traumatic brachial plexus
Spinal cord infarction is an unusual complication of intracranial neuroendovascular intervention. The authors report on two cases involving spinal cord infarction after endovascular coil embolization for large basilar-tip aneurysms. Each aneurysm was sufficiently embolized by the stent/balloon combination-assisted technique or double catheter technique. However, postoperatively, patients presented neurological symptoms without cranial nerve manifestation. MRI revealed multiple infarctions at the cervical spinal cord. In both cases, larger-sized guiding catheters were used for an adjunctive technique. Therefore, guiding catheters had been wedged in the vertebral artery (VA). The wedge of the VA and flow restriction may have caused thromboemboli and/or hemodynamic insufficiency of the spinal branches from the VA (radiculomedullary artery), resulting in spinal cord infarction. Spinal cord infarction should be taken into consideration as a complication of endovascular intervention for lesions of the posterior circulation.
spinal cord infarction; intracranial aneurysm; neuroendovascular intervention; complication
This is a literature review on to the use of endovascular therapy in hyperacute ischaemic stroke secondary to large vessel occlusion (LVO). The prognosis for LVO is generally poor and the efficacy of intravenous tissue plasminogen activator (IV TPA) in the treatment of this subtype of stroke is questionable. It is well documented that recanalisation is associated with improved outcomes but IV TPA has limited efficacy in LVO recanalisation and the complication rates are higher for IV TPA in this stroke subset.
Improved recanalisation rates have been demonstrated with intra-arterial TPA and first and second generation mechanical techniques but the rate of favourable outcome has not overtly mirrored this improvement.
Several controversial trials using these early techniques have recently been published but fail to reflect modern practice which centres on the use of stent-retriever technology. This has been proven to be superior to older techniques. Not only are recanalisation rates higher, but the speed of recanalisation is greater and clinical results are improved.
Multiple observational studies demonstrate consistently high rates of LVO recanalisation; TICI 2b/3 in the order of 65-95% and, rates of favourable outcome (mRS 0-2) in the order of 55% (42.5-77%) in clinically moderate to severe stroke with complicating symptomatic haemorrhage in the order of 1.5-15%.
A major factor determining outcome is time to treatment but success has been demonstrated using these devices with bridging therapy, after IV TPA failure or as a stand-alone treatment.
stroke; endovascular; thrombolysis; thrombectomy; stent-retriever; Solitaire; Trevo
Interventional Neuroradiology (INR) is not bound by the classical limits of a speciality, and is not restricted by standard formats of teaching and education. Open and naturally linked towards neurosciences, INR has become a unique source of novel ideas for research, development and progress allowing new and improved approaches to challenging pathologies resulting in better anatomo-clinical results. Opening INR to Neurosciences is the best way to keep it alive and growing. Anchored in Neuroradiology, at the crossroad of neurosciences, INR will further participate to progress and innovation as it has often been in the past.
interventional neuroradiology; training; Basic science