Umair Khan

Mycotic Pseudoaneurysm Associated with Skull Base Osteomyelitis Treated with Endovascular Embolization

Pseudoaneurysms occur due to malformations in arterial wall uniformity, leading to blood collection between the outer arterial layers and resultant outpouching of the vessel. Unlike true aneurysms, pseudoaneurysms do not involve all layers of the blood vessel. Mycotic pseudoaneurysms can occur after associated vessel adventitia infection, leading to transmural dissection. Here we present a case of a 78-year-old man with a history of chronic otitis externa and osteomyelitis who presented with increasing right ear pain with bloody discharge and associated headache. Catheter angiography demonstrated a large pseudoaneurysm in the right middle meningeal artery (MMA) at the base of the skull. Based on the clinical findings and the patient’s history, the patient was ultimately diagnosed with mycotic pseudoaneurysms of the MMA. The patient was subsequently treated with antibiotics as well as endovascular embolization and recovered without any complications.

Mechanical Thrombectomy for Acute Ischemic Stroke After Cardiac Surgery

Ischemic stroke is a rare yet devastating complication that may occur following cardiothoracic surgery. Fibrinolytic treatment is contraindicated due to elevated risk for hemorrhage. Mechanical thrombectomy entails a catheterized approach wherein the thrombus is physically removed from the vessel without the use of fibrinolytics, minimizing the possibility of intracranial hemorrhage. Here, we present two original cases of mechanical thrombectomy as treatment for patients experiencing emergent large vessel occlusion following cardiothoracic surgery. A literature review was conducted to determine current treatment guidelines, risk factors, and complications resulting from recanalization due to mechanical thrombectomy versus fibrinolytic therapy. One patient was admitted due to chronic, American College of Cardiology/American Heart Association stage D, New York Heart Association functional class IV heart failure and required complete, artificial hemodynamic support for two weeks and on the 19th day experienced neurologic decline secondary to a supraclinoid left internal carotid artery (ICA) occlusion. Mechanical thrombectomy resulted in distal reperfusion and neurologic improvement. The second patient presented with coronary artery disease and underwent triple coronary artery bypass grafting and endovein harvesting. On post-operative day 2, the patient experienced a left ICA occlusion extending to the cavernous ICA resulting in speech impairment and right-sided weakness. The patient was heparinized and underwent mechanical thrombectomy, resulting in immediate speech and muscle strength recovery. Medical advances allow mechanical thrombectomy to be performed in a timely and effective manner at specialized treatment centers. It offers endovascular treatment modalities to a unique patient population with postoperative stroke. In such patients, thrombectomy can safely provide reperfusion while reducing the risk of complications associated with conventional thrombolytics.

A Direct Aspiration First Pass Technique for Mechanical Thrombectomy in the Setting of a Suspected Cerebral Aneurysm

There is little guidance in the literature on which thrombectomy technique is preferred in patients with acute ischemic stroke and concomitant aneurysms. Here, we present the case of a 58-year-old female with an acute ischemic stroke requiring emergent thrombectomy that was complicated by the presence of multiple, nonruptured intracranial aneurysms. Imaging confirmed an occlusion of the right middle cerebral artery and multiple nonruptured intracranial aneurysms. The patient was administered intravenous recombinant tissue plasminogen activator and the thrombus was aspirated via a direct aspiration first pass technique (ADAPT). Her symptoms improved significantly postoperatively with a consequent National Institutes of Health Stroke Scale (NIHSS) score of 0. The purpose of this case report is to give an overview and compare various techniques that can help guide the physician for safe, early revascularization while reducing recanalization time in patients having an ischemic stroke who also harbor intracranial aneurysms.

Preoperative Embolization in Tandem with Surgical Resection for Cerebral Arteriovenous Malformations

A number of treatment options are available for cerebral arteriovenous malformations (AVMs) including surgical resection, stereotactic radiosurgery, and endovascular embolization. Endovascular embolization may be used pre-operatively to reduce the size of large AVMs and thus reduce surgical complications. Here we present two patients who successfully underwent preoperative embolization of their AVMs and subsequent surgery. Preoperative embolization is a viable option for AVMs to reduce complications and improve patient outcomes.

Coil Now, Pipe Later: Two-stage Treatment for Acute Intracranial Aneurysm Rupture

The two main treatment modalities of acute intracranial aneurysm rupture are endovascular embolization and surgical clipping, each with its own benefits and risks. Endovascular treatment is associated with better outcomes compared to surgical clipping, but is also associated with high recurrence rates. We present the case of a patient with an acutely ruptured intracranial aneurysm, who subsequently underwent partial endovascular coiling acutely, and later underwent flow diversion therapy with the Pipeline Embolization Device. We also review the literature on this topic for further recommendations on treatment options of acute intracranial aneurysm rupture.

To Stent or Not to Stent: A Tale of Two Occlusions

Stenting and balloon angioplasty, along with mechanical thrombectomy, have gained notability as adjunctive treatment options to intravenous tissue plasminogen activator (IV-tPA) for tandem internal carotid artery (ICA) and middle cerebral artery (MCA) occlusions (TIM occlusions). Acute ischemic strokes (AISs) secondary to TIM occlusions are associated with poor patient outcomes primarily due to low recanalization rates following intravenous thrombolysis, consequently prompting the need for more invasive recanalization efforts. Often, the treatment algorithm is based on the success of the initial angioplasty, suspected volume of completed infarction, and whether or not thrombolytics are utilized. Here, we present two patients with AIS due to TIM occlusions where two different treatment modalities were implemented for recanalization efforts. Patient 1 did not receive IV-tPA and was successfully managed with balloon angioplasty and subsequent carotid stenting followed by direct oral anticoagulant (DOAC) administration. Patient 2 received IV-tPA and balloon angioplasty without carotid stenting followed by intracranial mechanical thrombectomy. Complete recanalization was attained in both cases. Administration of IV-tPA can make subsequent carotid stenting a potentially higher-risk treatment option for patients with TIM due to potential hemorrhagic complications in the setting of requisite antiplatelet agents. Each case of AIS resulting from a TIM must be considered unique, and the use of IV thrombolytics, balloon angioplasty, carotid stenting, and mechanical thrombectomy alone or in combination must be tailored to the individual clinical parameters.

Spontaneous Intracranial Hypotension Presenting as a "Pseudo-Chiari 1"

Spontaneous intracranial hypotension (SIH) is classified as a decrease in cerebrospinal fluid (CSF) pressure secondary to a CSF leakage and consequent descent of the brain into the foramen magnum. Diagnosing SIH can be difficult due to its overlapping findings with Arnold-Chiari type 1 Malformation (CM1) where the cerebellar tonsils herniate into the foramen magnum. The similarity of both conditions calls for a more reliable imaging technique to localize the CSF leak which could narrow the differential diagnosis and aid in choosing the correct treatment. Here, we present a case of a 28-year-old female, ten weeks post-partum with symptoms similar to SIH. MRI of the brain was remarkable for tonsillar herniation below the foramen magnum. Literature was reviewed for additional neuroradiology techniques that would aid in narrowing our differential diagnosis. Interestingly, computed tomography-, digital subtraction-, and magnetic resonance myelography with intrathecal gadolinium are the preferred techniques for diagnosis of high flow and low flow CSF leaks, respectively. These modalities further aid in choosing the correct treatment while avoiding complications. Literature suggests that treatment for CM1 involves posterior fossa decompression, whereas the mainstay of treatment for SIH involves an epidural blood patch (EBP). Thus, our patient was treated with an EBP and recovered without complication.

Large Transcalvarial Meningioma: Surgical Resection Aided by Preoperative Embolization

Meningiomas are the most common type of primary brain tumors, accounting for about 30% of all brain tumors. Meningiomas originate from the meninges and can be associated with any part of the skull. Classification of meningiomas is based upon the World Health Organization (WHO) classification system and prognosis of meningiomas can be determined via histologic grading. Surgery is the gold standard treatment option for all types of meningiomas. Due to the high vascularity of some meningiomas, surgical resection can lead to certain complications including intraoperative blood loss and hemorrhage. Strategies for complication avoidance include preoperative embolization of the meningioma vascular supply. Preoperative embolization has been shown to assist in surgical resection of selected tumors and decrease intraoperative blood loss. We present a case of successful preoperative embolization for a large, complex, transcalvarial meningioma along with a literature review on this topic.

Percutaneous Vertebral Artery Access for Embolization of Cerebrovascular Disease: Illustrative Case and Operative Technique

Intracranial arteriovenous malformations can be further complicated by the development of aneurysms, which themselves carry the risk of rupture and hemorrhage. New endovascular techniques allow for more treatment options for these lesions in the setting of arteriovenous malformations. Here we present the case of a patient who developed an aneurysm in the setting of an arteriovenous malformation and subsequently underwent successful endovascular treatment via percutaneous access of the vertebral artery along with reviewing the literature on further treatment options and developments.

The Importance of Catheter Angiography in Computed Tomography Angiography-Negative Subarachnoid Hemorrhage

Computed tomography angiography (CTA) has become an effective tool in the evaluation of patients with subarachnoid hemorrhage (SAH), but it still has limitations. Up to 15% of non-traumatic SAH cases are negative on CTA. The benefits of catheter angiography in the evaluation of certain cases of CTA-negative SAH have been previously demonstrated. Here, we present the case of a 48-year-old female who presented with headache and right-sided hemiparesis, who later became apneic and required intubation. A computed tomography (CT) scan of the head demonstrated a diffuse SAH. A CTA of the head and neck showed no vascular abnormality. Catheter angiography diagnosed a conical-shaped aneurysm at the left A1-A2 junction of the anterior communicating artery complex measuring 3.5 mm by 1 mm. The aneurysm was successfully treated with a craniotomy and microvascular clipping using a 4.7 mm curved Yasargil miniclip (Aesculap, Tuttlingen, Germany). This case illustrates the importance and benefit of catheter angiography in CTA-negative cases of SAH.