Thinesh Sivapatham

The versatile distal access catheter: The Cleveland clinic experience

BACKGROUND:Vascular access is fundamental to any endovascular intervention. Concentric Medical has developed the Outreach Distal Access Catheter (DAC), which affords stable access at the target vessel modulating the forces at play within the thrombectomy device complex. The DAC is a device with novel access characteristics useful in a host of other types of clinical scenarios. OBJECTIVE:To review our experience with the DAC family of devices, the theory, and method of use. METHODS:A retrospective review of all cases in which the DAC was used during the period 2008 to 2010 was conducted and the cases classified by indication. Catheter-related complications were recorded. The use of the DAC in a variety of settings including intracranial stenting, aneurysm coil embolization, and arteriovenous malformation embolization is described. RESULTS:The DAC was used in 103 procedures performed in 93 patients between August 2008 and February 2010. Indications included acute stroke, treatment of intracranial atherosclerosis, vasospasm therapy, arteriovenous malformation embolization, and aneurysm embolization. In those procedures, 113 catheters were used. No complications directly attributable to DAC use were identified. CONCLUSION:The DAC is useful for gaining access to the cerebral vasculature, especially in patients with significant tortuosity or when re-access of distal vasculature is required multiple times.

An Analysis of Inflation Times During Balloon-Assisted Aneurysm Coil Embolization and Ischemic Complications

Background and Purpose— The introduction of balloon remodeling has revolutionized the approach to coiling of wide-neck aneurysms. We studied the effects of balloon inflation during coil embolization on ischemic complications. Methods— A retrospective review was undertaken of the most recent 147 patients undergoing balloon remodeling for unruptured intracranial aneurysm coil embolization at a single institution (81 balloon, 66 unassisted). All underwent postprocedural MRI. Results— Among patients in the “balloon” group, the mean total inflation time was 18 minutes (range, 1–43), a mean number of inflations of 4 (range, 1–9), a mean maximum single inflation time of 7 minutes (range, 1–19), a mean reperfusion time of 2.2 minutes between inflations, and an average procedure time of 2 hours and 10 minutes. Asymptomatic diffusion-weighted imaging abnormalities were detected on postprocedural MRI in 21.5% of patients and symptomatic lesions were identified in 3.8%. Both silent and symptomatic ischemic rates were similar in the internal control group. Patients with ischemic findings were older and more likely have diabetes; no differences were found with respect to total balloon inflation time, number of inflations, maximum inflation time, or reperfusion times. Conclusions— We found no significant relationship between balloon inflation practices and ischemic events. Older and diabetic patients were more likely to have ischemic events develop.

Combined surgical and endovascular approach to a complex dural arteriovenous fistula involving the superior sagittal sinus and torcula.

A complex dural arteriovenous fistula (dAVF) may require complex treatment strategies to achieve successful obliteration. We describe a combined open surgical and endovascular approach to a dAVF involving the superior sagittal sinus (SS) and torcula. A 68-year-old male with Factor V Leiden mutation presented with altered mental status from venous hypertension secondary to a complex, high-flow Borden III dAVF with internal carotid and bilateral external carotid artery feeders draining into the SS and torcula. Because the venous channel to the recipient SS at the point of convergence of the AV shunting was not accessible transfemorally due to venous stenosis, a surgical strategy using a midline burrhole for direct catheterization of the SS was devised. A balloon was inflated in the sinus during arterial embolization. This technique was effective in achieving embolization of multiple arterial feeders via a single vessel injection. Covered Atrium iCasts were introduced in a telescoping fashion after angioplasty of the posterior SS-torcular junction in an attempt to functionally occlude further AV shunting. Postembolization angiography revealed greatly diminished AV shunting with improved intracranial transit time and retrograde cortical venous drainage. The patient was maintained on anticoagulation and made a complete recovery following the intervention; however, he subsequently deteriorated acutely, and died on postprocedure day 4. This case illustrates the difficulties associated with treating a complex AVF, describes a temporizing solution, and reports a potential complication from placing a covered stent in the SS.

Merci retrievers as access adjuncts for reperfusion catheters: the grappling hook technique.

BACKGROUND: Expeditious, stable access in acute ischemic stroke is foundational for mechanical revascularization. Proximal vascular tortuosity and unfavorable anatomy may impede the access necessary for revascularization, particularly when large-caliber catheters are used. We describe an approach using the Merci retriever to gain stable catheter access for aspiration. OBJECTIVE: To assess the technical feasibility of using the Merci retriever system as an access adjunct in acute ischemic stroke and tortuous ophthalmic segment anatomy. METHODS: The acute ischemic stroke database was queried, and 3 patients presenting with acute ischemic stroke and tortuous proximal anatomy who were treated with mechanical thrombectomy and the Merci retriever as an access adjunct were identified. Patient charts and procedure reports were reviewed. RESULTS: In each of the patients, the ophthalmic segment of the internal carotid artery proved difficult to navigate. An appropriately sized Merci retriever was deployed in the M1 segment. Gentle tension on the retriever was applied, altering the angle at which the aspiration catheter navigated the ophthalmic segment, affording rapid access past the ophthalmic artery origin and into the target vessel. The 18 L microcatheter and retriever were withdrawn, followed by aspiration and clot maceration with the Penumbra aspiration system. CONCLUSION: Tortuous proximal anatomy may impede access to an occluded vessel. Use of tension on a deployed Merci retriever straightens the course of the wire, changing the angle that the aspiration catheter makes with the vessel. In the setting of unfavorable anatomy, this technique may be used to advance an aspiration catheter to the target lesion.

Balloon-augmented carotid artery sacrifice with Onyx: a proof of concept study in a swine model

Introduction Carotid sacrifice remains a valuable tool in the treatment of select vascular lesions. Neurointerventionalists have relied on coil embolization as their primary means of carotid sacrifice, a procedure that can be lengthy and expensive with long fluoroscopy times. We investigated a novel technique for carotid sacrifice in a swine model using temporary balloon occlusion to achieve proximal flow arrest in the carotid artery while embolizing the vessel with a liquid embolic agent. Methods A total of 10 common carotid artery sacrifices were performed in pigs under fluoroscopic guidance. Various balloons were employed to achieve near total proximal flow arrest to allow an Onyx cast to accumulate in the target vessel. Results The technique for sacrifice was modified during the experiment with the final procedures yielding successful sacrifice using Onyx through a dimethylsulfoxide-tolerant catheter (Echelon 14) with the assistance of two fibered coils and a 5 mm×30 mm Hyperglide balloon resulting in a 2.5 cm long cast. Conclusion Carotid artery sacrifice using commercially available non-adhesive liquid embolic agents is feasible with balloon assistance, allowing for reduced radiation and material costs. Coils may be beneficial in providing an anchor point for liquid embolic deposition, as well as reducing the volume of liquid embolysate required to achieve vessel occlusion.

Embolic protection devices and the Penumbra 054 catheter: utility in tandem occlusions in acute ischemic stroke

Background Tandem proximal and distal occlusions in the setting of an acute stroke are therapeutic challenges. Treating either lesion first has its respective shortcomings. An approach is described which may lessen the probability of distal embolic events during emergency carotid angioplasty and stenting during an acute stroke, and simplify access to both a distal and proximal lesion. Clinical presentation A 58-year-old man presented with waxing and waning neurological examination with an NIH Stroke Scale varying from 4 to 21. CT angiography demonstrated a left internal carotid artery occlusion at its origin and a left middle cerebral artery occlusion. The CT scan failed to demonstrate significant ischemic changes so the patient was brought to angiography for treatment under conscious sedation. Intervention Triaxial access into the distal middle cerebral artery was achieved followed by brief aspiration and clot maceration by opening the vessel completely. An embolic protection device was deployed through the intermediate catheter which was subsequently removed. Stenting and angioplasty were then performed, followed by removal of the embolic protection device which had visibly trapped debris. Conclusion Embolic protection devices may have a role in the emergency treatment of proximal occlusions in the setting of an acute ischemic stroke. Safe deployment through an occluded vessel may be assisted by use of an intermediate catheter. The Penumbra 054 catheter may be used both to aspirate the distal thrombus and to house the embolic protection device as it is advanced past a proximal occlusion.

Particle embolization of the bilateral superior and inferior alveolar arteries for life threatening dental socket hemorrhage

Particle embolization for epistaxis and intra-oral hemorrhage are performed on an as needed basis by neurointerventionalists. A case is presented of massive oral hemorrhage associated with end stage liver disease coagulopathy after tooth extraction of bilateral maxillary and mandibular molars. A man in his fifties with end stage liver disease who presented for evaluation of a syncopal episode was determined to be in hemorrhagic shock from 2 days of persistent oral bleeding after elective tooth extractions. Conservative management with multiple blood transfusion products, packing and vasoconstrictive spray was ineffective. Microcatheter angiograms of the alveolar arteries demonstrated blood and contrast pooling within the sockets of the extracted teeth. Selection of the bilateral supplying alveolar and inferior alveolar artery branches was achieved followed by polyvinyl alcohol particle embolization (250–355 μm). Polyvinyl alcohol particle embolization of dental socket hemorrhages is technically feasible and effective.

Stenting of a symptomatic long-segment extracranial vertebral artery occlusion

We present a 56-year-old man who presented with bilateral vertebral artery occlusions and recurrent transient ischemic attacks and strokes despite maximal medical therapy. A long-segment extracranial right vertebral occlusion was noted and successfully reconstructed with four drug-eluting stents. The patient has been symptom free for 3 months and does not exhibit restenosis on follow-up angiography. Stenting and angioplasty of a long-segment vertebral artery occlusion is technically feasible in select cases.

Benefits of a multidisciplinary environment for neurointerventional training: fellows' perspectives

Endovascular neurointervention is an exciting and rapidly growing field that is revolutionizing the treatments and approaches for both hemorrhagic and ischemic cerebrovascular disease. Originally the domain of neuroradiologists who pioneered and perfected methods of diagnostic cerebral angiography, the burgeoning discipline of neurointervention grew to encompass ever more therapeutic procedures. Subsequently, neurosurgeons have sought out training in neurointerventional techniques, enriching their therapeutic armamentarium, supplementing their surgical expertise in the management of aneurysms, dural arteriovenous fistulae and arteriovenous malformations. More recently, just as neurosurgeons were lured into hybrid training in both open and endovascular technique to treat hemorrhagic disease, stroke neurologists are filling fellowship positions with a particular interest in the interventional management of ischemic diseases of the cerebrovasculature, ranging from acute ischemic stroke to intracranial and extracranial stenoses and occlusions. In Europe, for political and historical reasons, a traditional model is followed in which the lions share of the neurointerventional work has remained in the realm of neuroradiologists. However, in the USA, the convergence of the three subspecialties (neurosurgery, stroke neurology and neuroradiology) in this field creates the unique opportunity for a truly multidisciplinary effort with obvious implications for improved patient care, exemplified in the revised name of the Society of Neurointerventional Surgery (SNIS), reflecting the present reality of endovascular neurointerventional surgery as practiced by clinicians hailing from three neuroscience backgrounds. A multidisciplinary environment that is collegial can greatly benefit fellowship training and both junior and senior practicing attendings. At the Cleveland Clinic, an accredited council for graduate medical education (ACGME)- approved fellowship in endovascular neurosurgery has been in place since 1 July 2003, with two positions offered yearly. Mirroring the rubric of the multidisciplinary Cerebrovascular Center, in which physicians from diverse specialties share administrative and financial interests (disease centric model, …

Centenarian middle cerebral artery occlusion treated with intra-arterial mechanical embolectomy

Advanced age, arbitrarily defined as over 80 years, has been an exclusion criterion in many clinical trials for the treatment of acute ischemic stroke. The oldest person, to our knowledge, treated for acute ischemic stroke with intra-arterial therapy is presented and, importantly, this patient was excluded from intravenous tissue plasminogen activator due to an advanced age of 100 years and arrival in our emergency department within the 3–4.5 h time window. Utilizing an MRI based protocol to assess the risk–benefit ratio, treatment by intra-arterial mechanical embolectomy was commenced resulting in middle cerebral artery recanalization at 6 h 30 min. The patient improved, and ultimately returned to a baseline modified Rankin Scale score of 3. With careful selection, elderly patients may benefit from acute stroke therapies and may be considered on a case by case basis.