Samuel Moscovici

Delayed complications after flow-diverter stenting: Reactive in-stent stenosis and creeping stents

We assessed the frequency and severity of changes in stent configuration and location after the treatment of intracranial aneurysms, and patterns of in-stent stenosis. We retrospectively reviewed data for consecutive aneurysm patients managed with endovascular implantation of flow-diverter stents (Silk Flow Diverter [Balt Extrusion, Montmorency, France] and Pipeline Embolization Device [ev3/Coviden, Minneapolis, MN, USA]) from October 2011 to July 2012. Routine 2, 6, 9-12, and 16-20 month follow-up angiograms were compared, with a focus on changes in stent configuration and location from immediately after deployment to angiographic follow-up, and the incidence and development of in-stent stenosis. Thirty-four patients with 42 aneurysms met inclusion criteria. The Silk device was implanted in 16 patients (47%, single device in 15), the Pipeline device in 18 (53%, single device in 16). On first follow-up angiography, in-stent stenosis was observed in 38% of Silk devices and 39% of Pipeline devices. In-stent stenosis was asymptomatic in 12 of 13 patients. One woman presented with transient ischemic attacks and required stent angioplasty due to end tapering and mild, diffuse in-stent stenosis. Configuration and location changes, including stent creeping and end tapering were seen in 2/16 patients (13%) with Silk devices, and 0/18 patients with Pipeline devices. We describe stent creeping and end tapering as unusual findings with the potential for delayed clinical complications. In-stent stenosis, with a unique behavior, is a frequent angiographic finding observed after flow-diverter stent implant. The stenosis is usually asymptomatic; however, close clinical and angiographic monitoring is mandatory for individualized management.

Polyetheretherketone implants for the repair of large cranial defects: a 3-center experience.

BACKGROUND Calvarial reconstruction of large cranial defects following decompressive surgery is challenging. Autologous bone cannot always be used due to infection, fragmentation, bone resorption, and other causes. Polyetheretherketone (PEEK) is a synthetic material that has many advantages in cranial-repair surgery, including strength, stiffness, durability, and inertness. OBJECTIVE To describe our experience with custom-made PEEK implants for the repair of large cranial defects in 3 institutions: San Francisco General Hospital, Hadassah-Hebrew University Hospital, and the National Neuroscience Institute, Singapore. METHODS A preoperative high-resolution computed tomography scan was obtained for each patient for design of the PEEK implant. Cranioplasty was performed via standard technique with the use of self-tapping titanium screws and miniplates. RESULTS Between 2006 and 2012, 66 cranioplasties with PEEK implants were performed in 65 patients (46 men, 19 women, mean age 35 ± 14 years) for repair of large cranial defects. There were 5 infections of implants and 1 wound breakdown requiring removal of the implant (infection and surgical removal rates of 7.6% and 9.1%, respectively). Two patients required drainage of postoperative hematoma (overall surgical complication rate, 12.7%). Nonsurgical complications in 5 patients included seizures, nonoperative collection, and cerebrospinal fluid rhinorrhea that resolved spontaneously. Overall median patient or family satisfaction with the cranioplasty and aesthetic result was good, 4 on a scale of 5. Temporal wasting was the main aesthetic concern. CONCLUSION Custom-designed PEEK implants are a good option for patients with large cranial defects. The rate of complications is comparable to other implants or autologous bone. Given the large size of these defects, the aesthetic results are good.

Emergent stent-assisted angioplasty of extracranial internal carotid artery and intracranial stent-based thrombectomy in acute tandem occlusive disease: technical considerations

Objective Tandem occlusions of the internal carotid artery (ICA) and a major intracranial artery respond poorly to intravenous thrombolytic therapy, and are usually managed by endovascular means. This study describes experience with stent-assisted endovascular ICA revascularization and stent-based thrombectomy. Methods In patients with tandem ICA–middle cerebral artery (MCA)/distal ICA occlusion, the carotid occlusion was recanalized by primary angioplasty and stent implantation, and the distal occlusion by stent-based thrombectomy. Two variant techniques are described. Results Seven consecutive patients, mean age 64.1 years (range 49–75) and mean admission National Institutes of Health Stroke Scale score of 23, were included. Occlusion sites were tandem proximal ICA and MCA trunk (six patients) and tandem proximal left ICA and ICA terminus (one patient). Complete recanalization with complete perfusion (Thrombolysis in Myocardial Infarction [TIMI] 3, Thrombolysis in Cerebral Infarction [TICI] 3) was achieved in six patients and partial recanalization with partial perfusion (TIMI 2, TICI 2A) in one. Mean time to therapy was 4.9 h (range 3–6.5); mean time to recanalization was 55 min (range 38–65 min). CT performed 1 day after recanalization showed cortical sparing (>90% of the cortex at risk) in seven patients. Five patients (72%) presented with good clinical outcome (modified Rankin Scale (mRS) score 0–2) at 1 month; one patient (patient No 7) reached an mRS score of 3 and one patient died. Conclusions In selected cases of acute ICA occlusion and concomitant major vessel embolic stroke, angioplasty and stenting of the proximal occlusion and stent-based thrombectomy of the intracranial occlusion may be feasible, effective and safe, and provide early neurological improvement. Further experience and prospective studies are warranted.

Recanalization with stent-based mechanical thrombectomy in anterior circulation major ischemic stroke.

We report the use of a self-expanding stent as a thrombectomy device in 17 patients (mean age 64.3 years) with major ischemic stroke secondary to large vessel occlusion. The patients had a mean National Institutes of Health Stroke Scale (NIHSS) score of >12, no cerebral hemorrhage or early infarction signs that affected more than 1/3 of the endangered territory, and an insufficient collateral supply. Within 8 hours of symptom onset, a stent (Solitaire; ev3, Irvine, CA, USA) was deployed across the occluded segment (endovascular bypass step). A repeat angiogram was performed to evaluate reconstituted flow. The guide-catheter balloon was inflated for proximal carotid occlusion. The partially deployed stent was slowly pulled back (mechanical thrombectomy step) under continuous aspiration. Complete recanalization (TIMI grade 3 flow) was achieved in fewer than 66 minutes after femoral access in all patients, with complete clot removal in a mean of two thrombectomy attempts. No stent was permanently implanted. Two patients developed asymptomatic hemorrhagic transformation (11.8%). Two patients presented post-recanalization parenchymal hemorrhage (11.8%); one suffered an intracerebral and intraventricular hemorrhage 12 hours after a successful and uneventful procedure and died 10 days later. The modified Rankin Scale scores were 0 to 2 in 15 patients (88.2%) and 3 in one patient (5.9%) at 1 month. In our preliminary experience, rapid stent-based mechanical thrombectomy has had unprecedented success.

Single-center experience on endovascular reconstruction of traumatic internal carotid artery dissections.

Background: Traumatic internal carotid artery dissection (CAD) has a potentially grave outcome. Anticoagulant therapy may be ineffective or contraindicated; surgery impractical. We present our experience with endovascular stenting in CAD patients. Methods: From 2004 to 2011, 23 patients with angiographically proven traumatic CAD underwent endovascular stent-assisted arterial reconstruction based on clinical and radiographic criteria: contraindication or failure of anticoagulation, evidence of impending ischemic stroke, or need for urgent intracranial revascularization. Dissections were graded based on degree of stenosis and extent of injury. Results: Seventeen patients (73.9%) presented with stroke or transient ischemic attack. Carotid revascularization was achieved with one (11 patients, 48%) or multiple stents (12 patients, 52%); distal protection was used rarely (three patients, 13%). No complications were directly attributed to stenting. Mean dissection-related stenosis improved from 72% ± 28.87% to 4% ± 8.29%. At a mean clinical follow-up of 28.7 months ± 31.9 months, 16 patients (69.6%) improved, six (26.1%) remained stable, and one (4.3%) had died secondary to multiple traumatic injuries. At long-term follow-up, no patient had a transient ischemic attack or stroke or presented evidence of de novo in-stent stenosis or stent thrombosis. There were no neurologic sequelae after partial or total discontinuation of antiplatelet therapy in seven patients undergoing trauma-related surgeries. Conclusions: Selected cases of traumatic CAD can be safely managed by endovascular stent-assisted angioplasty. Procedural complications are infrequent; the need for postprocedure antiplatelet therapy is a concern. Early detection is essential to avoid stroke. Stenting restores the integrity of the vessel lumen immediately, efficiently prevents the occurrence or recurrence of ischemic events, and avoids the need of long-term anticoagulation. Level of evidence: III.

Selective endovascular embolization for refractory idiopathic epistaxis is a safe and effective therapeutic option: technique, complications, and outcomes.

Epistaxis generally responds to conservative management, but a more invasive approach, such as superselective embolization, is sometimes justified. We report our experience with endovascular procedures in 19 patients from 2002 to 2011 for the treatment of refractory idiopatic posterior epistaxis. The sphenopalatine artery and distal internal maxillary arteries were embolized in all patients. Unilateral embolization was performed in 12 patients (63%), bilateral embolization in seven (37%). Additional embolization of the descending palatine artery was performed in eight patients (42%) and embolization of the facial artery and palatine arteries in four (21%). In one patient the distal ophthalmic artery was embolized with n-butyl cyanoacrylate. No minor or major complications occurred in relation to the embolization procedures. The average hospital stay was 11.1±8.6 days, including an average 5.2±3.4 days after embolization. Average follow-up after discharge was 21.3±25.7 months. Superselective endovascular embolization proved safe and effective in controlling idiopathic epistaxis, refractory to other maneuvers.

Do cranial subdural hematomas migrate to the lumbar spine

We report a patient with minor head trauma-related bilateral hemispheric subdural hematoma (SDH) and subsequent delayed spinal SDH or presumed migration to the lumbar spine. An acutely confused 88-year-old man presented to the Emergency Department after minor head trauma. Head CT scan revealed a small hemispheric SDH. The patient was admitted for observation. CT scan 6 hours later showed bilateral SDH with extension to the tentorium. Three days later SDH had resolved leaving bilateral subdural hygromas. Local leg weakness localized to the lumbar spine developed on day 6; spinal CT scan and MRI revealed a posterior L5-S1 collection. A pure subacute subdural hematoma compressing the cauda equina was drained after an L5 laminectomy. His lower leg weakness improved. The patient was discharged to rehabilitation two weeks after surgery. Patients with traumatic SDH who develop late-onset neurological deterioration attributable to any region of the spine should be evaluated for spinal SDH.

The use of flow diverter stents in the management of traumatic vertebral artery dissections.

Flow diverters constitute a new generation of flexible self-expanding stent-like devices with a high metal-surface area coverage, specifically designed for the endovascular management of complex cerebral aneurysms. Recently, other potential applications for these devices in the field of occlusive cerebrovascular disease have been described. In vertebral artery dissections causing occlusion associated with a burden of extensive clots, we have found that the reduced porosity of the diverter mesh serves as an effective barrier to in-stent clot protrusion and distal embolization. We describe the novel use of a flow diverter for the management of an occlusive traumatic vertebral artery dissection. Diverter implantation allowed subsequent angioplasty.

Ventriculoperitoneal shunt for intracranial hypertension in cryptococcal meningitis without hydrocephalus

The use of a ventriculoperitoneal (VP) shunt to treat uncontrollable intracranial hypertension in patients with cryptococcal meningitis without hydrocephalus is somewhat unusual and still largely unreported. However, uncontrollable intracranial hypertension without hydrocephalus in these patients is a potentially life-threatening condition. Early diagnosis and shunt placement are essential to improve survival and neurological function. We report uncontrollable intracranial hypertension without hydrocephalus in a 23-year-old woman, which was successfully managed by VP shunt placement.

Balloon-guided navigation technique to perform stenting in an acutely angled anterior cerebral artery

The complex anatomic features of wide-necked anterior communicating artery aneurysms represent an endovascular challenge. Compliant balloons and microstents are frequently required to achieve aneurysm occlusion. When the angle between the A1 and A2 segments is acute, microcatheter navigation is hazardous, and may be difficult or sometimes impossible with standard techniques. We present our technique using a support balloon to facilitate guidewire engagement and navigation of A2, and to assist with microcatheterization in this unfavorable vascular anatomy.