Biomedical subjects

Erol Veznedaroglu

Publications and source records attributed to Erol Veznedaroglu.

12 recordsLinked to original sources

PubMed2006

Feasibility and limitations of endovascular coil embolization of anterior communicating artery aneurysms: morphological considerations.

OBJECTIVE: The purpose of this study is to analyze anterior communicating artery (AComA) aneurysm morphology and its relationship to the limitations and feasibility of endovascular coil embolization. METHODS: One hundred twenty-three patients were treated with endovascular coil embolization for AComA aneurysms. Aneurysm morphology was classified into six categories according to the projection of the aneurysm (anterior, posterior/superior, or inferior) and neck size (< 4 mm or >or= 4 mm). The following categories were used: Class A1, anterior projection and neck of aneurysm less than 4 mm; Class A2, anterior projection and neck of aneurysm 4 mm or more; Class B1, posterior (superior) projection and neck of aneurysm less than 4 mm; Class B2, posterior (superior) projection and neck of aneurysm 4 mm or more; Class C1, inferior projection and neck of aneurysm less than 4 mm; and Class C2, inferior projection and neck of aneurysm 4 mm or more. Endovascular procedures were categorized as either successful or unsuccessful according to specific criteria. In addition, patients were followed for recanalization. Clinical follow-up data was obtained at discharge and after 6 months and was classified according to the Glasgow Outcome Scale. RESULTS: Complete or near complete aneurysm occlusion was observed in 108 (88%) patients, partial embolization was performed in three (2.4%) patients, and embolization was attempted in 12 (9.7%) patients. Successful embolization for AComA aneurysms was performed in 86 out of 123 (70%) patients or 77.5% (86 out of 111 patients) of those patients in whom embolization was possible. Statistical analysis demonstrated that anterior projecting aneurysms were more likely to be successfully coiled than either inferior or posterior/superior directed AComA aneurysms. In addition, inferiorly projecting AComA aneurysms and wide-neck aneurysms had a significantly higher rate of recanalization. CONCLUSION: Endovascular coil embolization of AComA aneurysms shows good outcome in our study. Despite advanced modern techniques, there are limitations in the endovascular approach to AComA aneurysms. Consideration of aneurysm morphology may be used to guide approaches in the treatment of AComA aneurysms.

Adult↗

PubMed2006

Endovascular treatment of spinal cord arteriovenous malformations.

Spinal cord arteriovenous malformations are rare lesions that represent one-tenth of the brain arteriovenous malformations. Depending on their location and relationship to the dura, these lesions are divided into four categories. Their clinical manifestations may vary from mild symptoms to severe motor deficits. Spinal angiography remains the "gold standard" for diagnosing spinal cord vascular lesions. Although the type of shunting remains difficult to determine by the magnetic resonance imaging, it is well analyzed by spinal angiography. The cure of the shunting is not by itself a therapeutic goal, but the objective is the creation of a new hemodynamic equilibrium between the lesion and the spinal cord to decrease the risk of hemorrhage and prevent the progression of the spinal cord ischemia. The endovascular tools seem to be a reasonable therapeutic option for the treatment of the majority of the spinal cord arteriovenous malformations.

Arteriovenous Malformations↗

PubMed2006

Endovascular management of intracranial aneurysms: current experience and future advances.

OBJECTIVE: The past 15 years have seen a revolution in the treatment of intracranial aneurysms. Endovascular technology has evolved rapidly since the Food and Drug Administration approval of Guglielmi detachable coils in 1995, which now allows successful treatment of most aneurysms. The authors provide a review of their 11-year experience at Jefferson Hospital for Neuroscience with endovascular embolization of intracranial aneurysms and discuss clinical trial outcomes and future directions of this treatment method. METHODS: The authors reviewed the clinical and angiographic outcomes for 1307 patients undergoing endovascular treatment of intracranial aneurysms. Their analysis focuses on posterior circulation and middle cerebral artery aneurysms, as well as cases of stent-assisted coil embolization. They review their procedural protocol and patient selection criteria for endovascular management. RESULTS: Several large clinical trials have demonstrated the safety and efficacy of endovascular treatment of intracranial aneurysms. The International Subarachnoid Aneurysm Trial provides Level I evidence demonstrating a significant reduction in disability or death with endovascular treatment compared with surgical clipping. The most common procedural complications include intraprocedural rupture and thromboembolic events; avoidance strategies are also discussed. Vasospasm after subarachnoid hemorrhage causes neurological morbidity and mortality and can be successfully managed by early recognition and interventional treatment with angioplasty, pharmacologic agents, or both. CONCLUSION: Long-term studies evaluating experience with aneurysm coil embolization during the past decade indicate that this is a safe and durable treatment method. The introduction of stent-assist techniques has improved the management of wide-neck aneurysms. Future technology developments will likely improve the durability of endovascular treatment further by delivering bioactive agents that promote aneurysm thrombosis beyond the coil mass alone. It is clear that endovascular therapy of both ruptured and unruptured aneurysms is becoming a mainstay of practice in this patient population. Although not replacing open surgery, the continued improvements have allowed aneurysms that previously were amenable only to open clip ligation to be treated safely with durable long-term outcomes.

Adolescent↗

PubMed2006

Endovascular management of acute symptomatic intracranial arterial occlusion.

OBJECTIVE: Acute ischemic stroke has reached epidemic proportions in the United States, affecting approximately 700,000 people annually. With the recent technological advancements in endovascular devices, clinicians now have tools capable of recanalizing acute intracranial occlusions. The combination of pharmacological thrombolysis and mechanical clot perturbation may result in increased rates of angiographic recanalization, which may lead to improvement in patient outcomes after acute stroke. METHODS: In this article, the various intra-arterial pharmacological and mechanical therapies used by interventionists to treat acute stroke are described. Strategies for using combinations of these therapies are discussed, as are preliminary radiographic and clinical outcomes. Techniques for complex mechanical stroke interventions are discussed in detail. RESULTS: Several advances in endovascular stroke technologies are becoming increasingly available. CONCLUSION: With proper patient selection, these therapies may lead to increased recanalization rates and better patient outcomes.

Acute Disease↗

PubMed2006

The endovascular operating room as an extension of the intensive care unit: changing strategies in the management of neurovascular disease.

Technological advances within the field of endovascular neurosurgery have influenced the management of the neurovascular patient within the intensive care unit (ICU). The endovascular operating room has, in fact, become an extension of the ICU in certain cases. Given the rapid development of new endovascular technologies, it is more important than ever for neurosurgeons to remain intimately involved with the care of their patients within the ICU. This article offers an overview of the evolution in ICU management of neurovascular disease and provides a framework for the incorporation of the endovascular operating room in the intensive care management of patients with this disease.

Cerebrovascular Disorders↗

PubMed2005

Carotid artery angioplasty and stent placement for recurrent stenosis.

OBJECT: The use of endovascular management for recurrent carotid artery (CA) stenosis is rapidly expanding due to the increased surgical risk associated with repeated carotid endarterectomy (CEA). Carotid artery angioplasty and stent placement for recurrent CA stenosis offers a less invasive strategy with fewer procedural complications and may provide a more durable treatment. The authors report on their experience with this procedure in the management of recurrent CA stenosis. METHODS: A retrospective review was performed to evaluate clinical and ultrasound imaging outcomes after CA angioplasty and stent placement. Twenty-three vessels in 22 patients with severe recurrent stenosis (> 80%) post-CEA were treated with balloon angioplasty and stent placement without distal protection. There were no perioperative neurological or cardiac complications in this series. Over a mean follow-up period of 36 months, one patient (5%) suffered recurrent stenosis requiring retreatment with angioplasty alone. CONCLUSIONS: The use of CA angioplasty and stent placement provides a safe and effective treatment for recurrent CA stenosis. The use of drug-eluting and/or bioactive stents in the future will likely further improve the efficacy of this procedure for recurrent CA stenosis.

Angioplasty↗

PubMed2005

The role of carotid angioplasty and stenting in carotid revascularization.

OBJECTIVES: The gold standard procedure for carotid revascularization has been carotid endarterectomy. Several randomized trials demonstrate that it is more efficacious than medical management in stroke prevention for both symptomatic and asymptomatic patients when performed with low surgical morbidity. However, many high-risk patients not included in these trials are now being referred for carotid revascularization. Endovascular treatment of carotid stenosis with angioplasty and stenting has become an established alternative to carotid endarterectomy (CEA) for these patients. We provide a review of the current role of carotid stent and angioplasty. METHODS: We reviewed our procedural techniques for carotid artery stenting (CAS) with an emphasis on the need for medical therapy before and after the procedure to reduce thromboembolic complications. We also retrospectively analysed our clinical outcomes and incidence of restenosis after CAS. RESULTS: We evaluated 139 of 252 patients treated over a 10-year period who had a minimum of 6-month clinical and imaging (ultrasound and/or angiography) follow-up (average f/u=60 months). Our rate of major stroke, MI or death was 3%, and rate of peri-operative TIAs was 2%. Morbidity related to femoral sheath placement has been 1.5%, with one 'cold foot' resolved with heparin and one retroperitoneal hematoma requiring transfusion. Recurrent stenosis after CAS occurred in 4% of patients, predominately following radiation treatment where it was 15%. DISCUSSION: Although CEA is the gold standard procedure to prevent stroke from carotid stenosis, CAS has an expanding role for revascualrization, particularly in high-risk patients. Several randomized prospective trials are ongoing to better define the indications for CAS versus CEA.

Angioplasty, Balloon, Coronary↗

PubMed2004

Stent-assisted coil placement for unruptured cerebral aneurysms.

OBJECT: The treatment of wide-necked cerebral aneurysms represents a challenging problem for neurosurgeons. The recent development of stents has provided clinicians with the ability to treat these aneurysms while keeping the parent vessel patent. The long-term occlusion rate of aneurysms treated with stent-assisted coil placement has yet to be investigated. The authors report the use of a new intracranial stent-the Neuroform microstent-in the treatment of unruptured wide-necked cerebral aneurysms. METHODS: Thirty-two patients harboring unruptured wide-necked intracranial aneurysms underwent a stent-assisted coil placement procedure. Patients were pretreated with antiplatelet agents, and a stent was positioned across the neck of the aneurysm. The next step was the insertion of coils into the aneurysm cavity. Patients received anticoagulation therapy for 24 hours after the procedure. All 32 patients with unruptured wide-necked cerebral aneurysms were suitable candidates for this procedure. Occlusion of at least 90% of the aneurysm was achieved in 24 patients (75%) and 0% occlusion was observed in five patients (15%). Two patients experienced thromboembolic events, one of which was directly related to the stent. The overall complication rate was 6.3%. CONCLUSIONS: Intracranial stents will be used more frequently in the new era of endovascular management of widenecked cerebral aneurysms. With some technical improvements and more data on long-term occlusion rates, this new modality should improve the occlusion of wide-necked cerebral aneurysms while protecting the parent vessel.

Adult↗

PubMed2004

Surgically treated aneurysms previously coiled: lessons learned.

OBJECTIVE: Intravascular coil embolization of cerebral aneurysms has proved to be a safe and effective treatment in certain patient groups; however, this treatment is relatively new, and the long-term outcomes are unknown. One of the known complications is refilling of the aneurysm dome, which is seen in follow-up studies. This patient population poses unique technical difficulties for the neurosurgeon. We present a series of 18 patients who underwent surgery for residual aneurysms after coil remobilization. METHODS: During a 5-year period, we performed surgery in 18 patients who had previously undergone coil embolization for their aneurysms. Of these aneurysms, four were in the anterior communicating artery, five were in the posterior communicating artery, three were in the internal carotid artery, three were in the posteroinferior cerebellar artery, and three were in the middle cerebral artery. One patient presented with rupture, one presented with acute IIIrd cranial nerve palsy, and the rest of the aneurysms were found on routine follow-up angiograms. Fifteen aneurysms were clipped, and in three patients, they were wrapped because the clip could not be placed adequately. RESULTS: There were no major complications in any of the patients, and all had uneventful recoveries. The presence of coils in the aneurysm dome and/or neck made clipping and exposure of the aneurysm neck difficult, resulting in incomplete neck obliteration in three patients. CONCLUSION: Operative clipping after previous coil embolization in aneurysms poses a unique problem for neurosurgeons. With the increasing use of coil embolization, this patient population will undoubtedly increase. The neurosurgeon should be aware of the difficulties and pitfalls encountered in these patients.

Adult↗

PubMed2004

Endovascular occlusion of wide-necked aneurysms with a new intracranial microstent (Neuroform) and detachable coils.

OBJECTIVE: The long-term durability of the endovascular occlusion of cerebral aneurysms is one of the major factors limiting the more widespread use of this technique. Long-term occlusion of wide-necked aneurysms has improved with new assistive devices that seem to improve aneurysm occlusion while protecting the parent vessel. We report the use of a new intracranial stent--the Neuroform microstent--in the treatment of patients with wide-necked cerebral aneurysms. METHODS: Patients identified as harboring wide-necked intracranial aneurysms were evaluated for stent-assisted coiling. After appropriate anticoagulation was performed, depending on whether the aneurysm was ruptured or unruptured, the Neuroform stent was delivered across the neck of the aneurysm and deployed with a coil pusher. After stent placement, standard coil occlusion of the aneurysm was achieved in the majority of cases. RESULTS: Fifty-six patients were identified as having wide-necked intracranial aneurysms suitable for stent-assisted coiling. A total of 49 aneurysms in 48 patients were treated with this procedure. In eight cases, stent deployment failed. Forty-one of the aneurysms were initially stented, followed by coil placement. Six aneurysms were stented only, and one aneurysm was initially coiled, followed by stent placement. There were five deaths (8.9%), one of which occurred secondary to a stroke after the procedure (1.8%). Four patients (7%) experienced thromboembolic events, three of which were considered to have been secondary to the procedure (5.3%). In addition, there were two femoral pseudoaneurysms. The overall complication rate was 10.7%. Five patients were available for follow-up angiographic evaluation, and their cases are discussed. CONCLUSION: Intracranial stenting may overcome important technical limitations in current endovascular therapy by improving the occlusion of wide-necked aneurysms while protecting the parent vessel.

Adult↗

PubMed2004

Fractionated stereotactic radiotherapy for the treatment of large arteriovenous malformations with or without previous partial embolization.

OBJECTIVE: Despite the success of stereotactic radiosurgery, large inoperable arteriovenous malformations (AVMs) of 14 cm(3) or more have remained largely refractory to stereotactic radiosurgery, with much lower obliteration rates. We review treatment of large AVMs either previously untreated or partially obliterated by embolization with fractionated stereotactic radiotherapy (FSR) regimens using a dedicated linear accelerator (LINAC). METHODS: Before treatment, all patients were discussed at a multidisciplinary radiosurgery board and found to be suitable for FSR. All patients were evaluated for pre-embolization. Those who had feeding pedicles amenable to glue embolization were treated. LINAC technique involved acquisition of a stereotactic angiogram in a relocatable frame that was also used for head localization during treatment. The FSR technique involved the use of six 7-Gy fractions delivered on alternate days over a 2-week period, and this was subsequently dropped to 5-Gy fractions after late complications in one of seven patients treated with 7-Gy fractions. Treatments were based exclusively on digitized biplanar stereotactic angiographic data. We used a Varian 600SR LINAC (Varian Medical Systems, Inc., Palo Alto, CA) and XKnife treatment planning software (Radionics, Inc., Burlington, MA). In most cases, one isocenter was used, and conformality was established by non-coplanar arc beam shaping and differential beam weighting. RESULTS: Thirty patients with large AVMs were treated between January 1995 and August 1998. Seven patients were treated with 42-Gy/7-Gy fractions, with one patient lost to follow-up and the remaining six with previous partial embolization. Twenty-three patients were treated with 30-Gy/5-Gy fractions, with two patients lost to follow-up and three who died as a result of unrelated causes. Of 18 evaluable patients, 8 had previous partial embolization. Mean AVM volumes at FSR treatment were 23.8 and 14.5 cm(3), respectively, for the 42-Gy/7-Gy fraction and 30-Gy/5-Gy fraction groups. After embolization, 18 patients still had AVM niduses of 14 cm(3) or more: 6 in the 7-Gy cohort and 12 in the 5-Gy cohort. For patients with at least 5-year follow-up, angiographically documented AVM obliteration rates were 83% for the 42-Gy/7-Gy fraction group, with a mean latency of 108 weeks (5 of 6 evaluable patients), and 22% for the 30-Gy/5-Gy fraction group, with an average latency of 191 weeks (4 of 18 evaluable patients) (P = 0.018). For AVMs that remained at 14 cm(3) or more after embolization (5 of 6 patients), the obliteration rate remained 80% (4 of 5 patients) for the 7-Gy cohort and dropped to 9% for the 5-Gy cohort. A cumulative hazard plot revealed a 7.2-fold greater likelihood of obliteration with the 42-Gy/7-Gy fraction protocol (P = 0.0001), which increased to a 17-fold greater likelihood for postembolization AVMs of 14 cm(3) or more (P = 0.003). CONCLUSION: FSR achieves obliteration for AVMs at a threshold dose, including large residual niduses after embolization. With significant treatment-related morbidities, further investigation warrants a need for better three-dimensional target definition with higher dose conformality.

Adult↗

PubMed2002

Extravascular collagen in the human epileptic brain: a potential substrate for aberrant cell migration in cases of temporal lobe epilepsy.

OBJECT: Several lines of evidence have demonstrated a number of cellular changes that occur within the hippocampus in patients with temporal lobe epilepsy (TLE). These include aberrant migration of granule cells and sprouting of mossy fibers, processes that have been linked to the hyperexcitability phenomenon observed in cases of TLE. In the present study the authors examined brain tissues obtained in patients undergoing temporal lobectomy surgery and in patients at autopsy (normal human control specimens), and compared the subcellular composition of regions of the hippocampus containing dispersed granule cells. METHODS: Six human hippocampi were obtained in patients undergoing temporal lobectomies for intractable seizures. The patients ranged in age from 24 to 50 years. Two of the six patients had a history of head trauma and one had experienced a febrile seizure during childhood. Immediately following excision from the brain, the tissue was placed in an acrolein-paraformaldehyde fixative. The hippocampi were processed along with six human brain control specimens obtained at autopsy for light and electron microscopic evaluation. The tissues were then labeled for collagen types I through IV. Positive collagen labeling was identified, with the aid of both light and electron microscopy, in the parenchyma of all patients with TLE but not in the control tissues. CONCLUSIONS: The authors report the first localization of collagen outside of the vasculature and meninges in the brains of patients with TLE. Recent evidence of collagen's chemoattractant properties and its role in epileptogenesis in animal models suggests that collagen may play a role in cellular migration and seizure activity in a subset of patients. Further studies with a larger series of patients are warranted.

Adult↗