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Biomedical subjects

Kenneth Fraser

Publications and source records attributed to Kenneth Fraser.

12 recordsLinked to original sources
PubMed2006

The occipital artery: a microanatomical study.

OBJECTIVE: We performed a systematic microanatomical study of the occipital artery (OA) and its branches to describe the course, diameter, and branches of this vessel as well as the presence and pattern of anastomotic channels between the OA and the vertebral artery. METHODS: Twelve occipital arteries (6 adult cadaveric heads injected with colored latex) were studied using the surgical microscope. Particular attention was given to the course and branching pattern of the artery as well as the presence and type of anastomotic channels between the occipital artery and vertebral artery. RESULTS: Based upon anatomical considerations, the course of the occipital artery was divided into three segments. The first, or digastric segment, extends from the origin to the exit off the occipital groove of the mastoid process. The second segment, or suboccipital, extends from the occipital groove to the superior nuchal line. The third, or terminal segment, corresponds to the subgaleal segment just above the superior nuchal line up to the vertex. Two main descending branches of the second segment or suboccipital were identified. The superficial descending branch (SDB) runs between the splenium capitis and semispinalis capitis while the deep descending branch (DDB) enters the suboccipital triangle. Anastomotic vessels between one of these two descending branches and branches of the vertebral artery were found in 11 out of the 12 OAs dissected (91%). CONCLUSION: Detailed knowledge of the OA anatomy is helpful in choosing this vessel as a donor for extra-intracranial bypasses. More importantly, knowledge and understanding of the type and pattern of anastomoses between the OA and the vertebral artery are critical to avoid disastrous complications (i.e., posterior circulation stroke) during embolization of vascular or neoplastic processes fed by distal OA branches.

Anatomy, Regional↗
PubMed2006

Treatment of ruptured intracranial aneurysms since the International Subarachnoid Aneurysm Trial: practice utilizing clip ligation and coil embolization as individual or complementary therapies.

OBJECT: The aim of this study was to analyze the therapeutic decision-making process and outcome in 100 consecutive patients with aneurysmal subarachnoid hemorrhage (SAH) treated since the completion of the International Subarachnoid Aneurysm Trial (ISAT). All patients were evaluated and treated by a neurosurgeon with subspecialty training in both cerebrovascular and neuroendovascular surgery. METHODS: One hundred consecutive patients with aneurysmal SAH who had been admitted within 1 week posthemorrhage and who had been treated using either surgical clip application or endovascular coil embolization were included in this analysis. All patients underwent a uniform perioperative protocol. All surviving patients were given a questionnaire to assess their modified Rankin Scale score (mRS) and to grade themselves at 6 months and 1 year postintervention. The cohort consisted of 73 women and 27 men with a mean age of 57.27 years (range 27-87 years). Twenty-nine percent of the patients had a World Federation of Neurosurgical Societies (WFNS) Grade IV or V SAH. Forty-seven patients underwent direct surgical clip application, 41 endovascular embolization, and 12 a combination of the two procedures. Good functional outcome--indicated by mRS scores of 0 to 2 after at least 6 months--was achieved in 71% of patients. CONCLUSIONS: Data from the ISAT demonstrated a better functional outcome following endovascular embolization in a selected group of patients with aneurysmal SAH. In routine clinical practice, however, a significant number of patients still benefit from direct surgical clip ligation. Excellent functional results can be realized in a complementary clip ligation and coil occlusion practice in which each patient and aneurysm is evaluated and the two treatment modalities are used individually or, when needed, in combination.

Adult↗
PubMed2005

Evolution of endovascular therapy for aneurysm treatment. Historical overview.

The endovascular treatment of intracranial aneurysms has recently become an established therapeutic option. The foundation of this treatment modality was laid by the work done in ground-breaking cases, combined with technological advances since the first half of the 19th century. In this historical overview the authors describe the steps taken by the early pioneers and the results of their work, which was often done under challenging circumstances. The work of these predecessors established the stepping-stones for constant development and refinement for those who have come after them, eventually evolving into the procedures used today. Endovascular treatment of intracranial aneurysms is only possible because of the work of these innovators.

Balloon Occlusion↗
PubMed2005

Transaxillary carotid stenting: technical case report.

OBJECTIVE AND IMPORTANCE: As endovascular neurointerventions continue to evolve rapidly, angioplasty and stenting of both the extracranial and intracranial vessels have become more routine procedures. When the transfemoral approach is contraindicated or technically difficult, familiarity with alternative access techniques becomes essential. We report a successful transaxillary carotid stenting in a patient with an axillary bifemoral bypass graft. CLINICAL PRESENTATION: A 77-year-old man presented with a symptomatic high-grade stenosis (80%) of the left internal carotid artery. Because of the increased risk of general anesthesia related to his advanced age and severe comorbidities, stenting of the left internal carotid artery was considered. A left transaxillary approach was chosen because of the presence of an axillary bifemoral bypass graft. TECHNIQUE: Under ultrasound guidance, the left axillary artery was successfully punctured and cannulated. After a 0.038 Magic Torque wire (Boston Scientific/Medi-Tech, Watertown, MA) was anchored with the tip of the wire in the distal left occipital artery, a 7-French (outer diameter) Vista Bright guiding sheath (Cordis, Miami, FL) was successfully positioned in the mid left common carotid artery, with an MPA catheter (Cordis) used as guiding support. Subsequently, two Precise stents (Cordis) were successfully deployed across the stenosis, yielding a satisfactory angiographic result. CONCLUSION: With proper patient selection and the use of ultrasound guidance during the initial puncture, the transaxillary approach is a safe and technically feasible alternative to the transfemoral approach when performing carotid stenting.

Aged↗
PubMed2005

Emerging concepts in the treatment of intracranial aneurysms: stents, coated coils, and liquid embolic agents.

Endovascular techniques for the treatment of intracranial aneurysms are rapidly evolving. Modifications of more traditional coils have been introduced. Such modifications include newer coils coated with various polymers to increase both coil thrombogenicity and degree of aneurysm packing. In addition, newer coil designs aimed at improving the conformability of the coil to the aneurysm have been used with promising preliminary results. The availability of a newer generation of stents specifically designed for intracranial navigation allows for more effective treatment of aneurysms with wide necks, which usually have been considered unsuitable for optimal endovascular treatment. Endovascular alternatives to coil embolization, such as liquid embolic materials, also have been explored for the treatment of intracranial aneurysms, with varying results. We summarize the rationale for use of these newer devices and early clinical experiences. Areas of current research and future directions of endovascular aneurysm treatment also are discussed.

Embolization, Therapeutic↗
PubMed2005

Successful intra-arterial basilar artery thrombolysis in a patient with bilateral vertebral artery occlusion: technical case report.

OBJECTIVE AND IMPORTANCE: Basilar artery occlusion is a clinical event with an exceedingly high mortality rate. Improved survival is closely associated with successful recanalization of the occluded basilar artery. Bilateral vertebral artery occlusion (BVAO) is a unique disease entity that effectively denies any direct access to the basilar artery for endovascular rescue therapy. We report a case of successful intra-arterial basilar artery thrombolysis in a patient with BVAO. CLINICAL PRESENTATION: A 78-year-old man was transferred to our hospital after intravenous administration of tissue plasminogen activator and with deteriorating neurological status requiring intubation. His clinical presentation was highly suggestive of acute basilar artery thrombosis. The cerebral angiogram showed a BVAO and collateral flow reconstituting both distal extracranial vertebral arteries but with significant contrast stasis. There was no retrograde filling of the basilar artery through the only angiographically visible posterior communicating artery. TECHNIQUE: Selective catheterizations of the left occipital artery and the left ascending cervical branch of the thyrocervical trunk were performed to deliver a total of 12 mg of tissue plasminogen activator. At that point, the patient showed significant neurological improvement. The post-tissue plasminogen activator angiogram showed improved flow through the basilar artery. The patient was independent and well at his 1-year follow-up visit. CONCLUSION: Knowledge of potential collateral pathways is important when direct access to the main intracranial vessels is not available. Basilar artery thrombolysis through collateral vessels is clinically effective when a direct approach to the artery is not feasible.

Aged↗
PubMed2005

Emergent endovascular treatment with direct carotid puncture for exsanguinating Carotid Blowout Syndrome.

INTRODUCTION: Carotid Blowout Syndrome (CBS) carries an exceedingly high mortality rate. Various established endovascular techniques are successful in treating less acute CBS, but exsanguinating patients with hemodynamic compromise continue to pose a significant clinical challenge. METHODS: We report a 53-year-old male with squamous cell carcinoma of the anterior tongue presented with a sentinel hemoptysis followed by a massive oral hemorrhage. The patient suffered a cardiac arrest secondary to acute blood loss, from which he was successfully resuscitated. RESULTS: An occlusion technique is presented involving direct carotid puncture for successful treatment of hemodynamically unstable, exsanguinating patients. CONCLUSION: This technique accomplishes rapid arrest of exsanguination, minimal hemorrhage site manipulation, and successful carotid occlusion.

Balloon Occlusion↗
PubMed2004

Treatment Options for Unruptured Cerebral Aneurysm.

The management of unruptured cerebral aneurysm is controversial. Because the natural history of unruptured cerebral aneurysm is not well defined, the best management strategy is unclear. The current consensus on the management of unruptured cerebral aneurysm includes observation, microsurgical clipping, and endovascular treatment. The methodologies used to follow up a known unruptured aneurysm are controversial and may be dependent on the preferences of the treating physician. Most aneurysms are managed by the neurosurgeons and interventional neuroradiologists, but neurologists often are the first to discover the unruptured aneurysms when screening the patients for other neurologic disorders. Therefore, the knowledge on when to screen patients for and how to best manage an unruptured aneurysm will have a direct impact on their daily practices. Unruptured aneurysms often cause other neurologic symptoms including ischemic events, seizures, and headache. These symptoms may prompt more interventional treatment. Without a thoughtfully designed, true population-based study or randomized trial, the current best management will be based on the available literature and the temporal profile of each patient.

Journal Article↗
PubMed2004

Subacute spinal subdural hematoma after spontaneous resolution of cranial subdural hematoma: causal relationship or coincidence? Case report.

The etiopathogenesis of traumatic spinal subdural hematoma (SSH) is uncertain. Unlike the supratentorial subdural space, no bridging veins traverse the spinal subdural space. The authors describe a case of subacute SSH that occurred after spontaneous resolution of traumatic intracranial SDH and suggest a causal relationship between the two. A 23-year-old woman suffered an acute intracranial SDH after a snowboarding accident. There was no clinical or radiological evidence of spine injury. Conservative management of the supratentorial SDH resulted in spontaneous radiologically documented resolution with redistribution of blood in the subdural space. Four days after the injury, the patient started noticing new onset of mild low-back pain. The pain progressively worsened. Magnetic resonance imaging of the lumbosacral spine 10 days after the original injury revealed a large L4-S2 SDH. Ten days after the original injury, bilateral L5-S1 laminotomy and drainage of the subacute spinal SDH were performed. The patient experienced immediate pain relief. The authors hypothesize that in some cases spinal SDH may be related to redistribution of blood from the supratentorial subdural space.

Accidents↗
PubMed2003

Urgent endovascular treatment of acute symptomatic occlusion of the cervical internal carotid artery.

OBJECT: The prognosis of patients with acute symptomatic cervical internal carotid artery (ICA) occlusion is generally considered to be poor. Traditionally, such patients are not considered eligible for urgent thrombolytic/endovascular treatment. Since 1998, an aggressive therapeutic approach with endovascular treatment has been adopted at the authors' institution. In this report they assess whether aggressive treatment of ICA occlusion is appropriate. METHODS: The clinical characteristics and outcome of six consecutive patients treated urgently with an endovascular approach between 1998 and 2001 are reviewed and summarized. Recanalization was accomplished in all patients. At a mean follow-up period of 8 months (range 2-14 months), five of six patients had good or excellent outcomes (modified Rankin Scale [mRS] Score 0-1) and one had a poor outcome (mRS Score 4). CONCLUSIONS: With recent advancements in thrombolytic and endovascular treatments, an aggressive endovascular approach in patients with acute symptomatic cervical ICA occlusion may be successful. Further clinical data are required to determine the optimal endovascular approach in these patients.

Acute Disease↗
PubMed2003

Treatment of aneurysms with wires and electricity: a historical overview.

Endovascular treatment of aneurysms has only recently become an accepted therapeutic modality. Nonetheless, treatment of aneurysms with the aid of various foreign bodies such as needle and wire insertion with or without electrical current has been reported since the first half of the 19th century. In 1832 Phillips induced clot formation in the femoral and carotid arteries of dogs by leaving needles in the arteries for variable lengths of time. Simultaneously, in France, Velpeau had proposed using "l'acupuncture des arteres dans le traitement des anevrismes." Later, Phillips and Pelrequin connected the offending needles to a source of electrical current in an attempt to increase thrombus formation and aneurysm occlusion. Subsequently, Moore introduced the concept of packing the aneurysm with wire inserted through a needle transfixed to the vessel wall. To this method, Corradi added electrical current. Widely known as the Moore-Corradi technique, it was used in ensuing years with variable success. The early phase of endovascular aneurysm treatment culminated when Blakemore and Moore treated a case of symptomatic cavernous sinus aneurysm by passing wire through the patient's orbit. These pioneering cases combined with technological advances in the diagnosis of intracranial aneurysms paved the way for further refinements in coil embolization of aneurysms.

Aneurysm↗