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Biomedical subjects

F Charbel

Publications and source records attributed to F Charbel.

At least 19 recordsLinked to original sources

Contemporary management of subarachnoid hemorrhage and vasospasm: the UIC experience.

BACKGROUND: Cerebral vasospasm is a well-known and serious complication of aneurysmal subarachnoid hemorrhage. The means of monitoring and treatment of vasospasm have been widely studied. Each neurosurgical center develops a protocol based on their experience, availability of equipment and personnel, and cost, so as to keep morbidity and mortality rates as low as possible for their patients with vasospasm. METHODS: At the University of Illinois at Chicago, we have developed algorithms for the diagnosis and management of cerebral vasospasm based on the experience of the senior authors over the past 25 years. This paper describes in detail our approach to diagnosis and treatment of aneurysmal subarachnoid hemorrhage and vasospasm. Our discussion is highlighted with data from a retrospective analysis of 324 aneurysm patients. RESULTS: Over 3 years, 324 aneurysms were treated; 185 (57%) were clipped, 139 (43%) were coiled. The rate of vasospasm for the 324 patients was 27%. The rate of hydrocephalus was 32% for those patients who underwent clipping, and 29% for those coiled. The immediate outcomes for those who underwent clipping was excellent in 35%, good in 38%, poor in 15.5%, vegetative in 3%, and death in 8% of the patients. For those who underwent coiling the immediate outcome was excellent in 64%, good in 14.5%, vegetative in 2.5%, and death in 14.5% of the patients. These statistics include all Hunt and Hess grades. For those patients who underwent clipping, 51% were intact at 6 months follow-up, 15% had a permanent deficit, 10% had a focal cranial nerve deficit, and 2% had died from complications not directly related to the procedure. For those patients who had undergone coiling, 75% were intact at 6 months follow-up, 12.5% had a permanent deficit, and 12.5% had a cranial nerve deficit, with no deaths. CONCLUSIONS: The morbidity and mortality of cerebral vasospasm is significant. A good outcome after aneurysmal subarachnoid hemorrhage is dependent upon careful patient management in the preoperative, perioperative, and postoperative periods. The timely work-up and aggressive treatment of neurological deterioration, whether or not it is because of vasospasm, is paramount.

Algorithms↗

Construction of a physical model of the human carotid artery based upon in vivo magnetic resonance images.

A method is described for construction of an in vitro flow model based on in vivo measurements of the lumen geometry of the human carotid bifurcation. A large-scale physical model of the vessel lumen was constructed using fused deposition modeling (a rapid prototyping technique) based on magnetic resonance (MR) images of the carotid bifurcation acquired in a healthy volunteer. The lumen negative was then used to construct a flow model for experimental studies that examined the hemodynamic environment of subject-specific geometry and flow conditions. The physical model also supplements physician insight into the three-dimensional geometry of the arterial segment, complementing the two-dimensional images obtained by MR. Study of the specific geometry and flow conditions in patients with vascular disease may contribute to our understanding of the relationship between their hemodvnamic environment and conditions that lead to the development and progression of arterial disease.

Adult↗

Intracranial percutaneous transluminal angioplasty for arteriosclerotic stenosis.

BACKGROUND: Patients with intracranial arteriosclerotic disease have significant morbidity and mortality rates, and some are unresponsive to medical treatment and have unacceptable surgical risks. Percutaneous transluminal angioplasty of the intracranial vessels is a possible alternative to surgery. OBJECTIVES: To present our experience with percutaneous transluminal angioplasty and to summarize our data. PATIENTS AND METHODS: Sixteen patients underwent intracranial percutaneous transluminal angioplasty for high-grade arteriosclerotic stenosis based on strict inclusion and exclusion criteria. All patients had symptoms referable to the stenosis except one. Angioplasty was performed in 6 intracranial vertebral arteries, 3 basilar arteries, 5 middle cerebral arteries, and 3 distal internal carotid arteries. One patient had concomitant stent placement. RESULTS: There was 1 treatment failure secondary to tortuous vascular anatomy. Vessel caliber was increased to more than 80% of normal in 6 patients and to 50% to 70% of normal in 6 patients, with a reduction of symptoms. Three intimal dissections occurred during angioplasty; one of these, in a precavernous segment of the internal carotid artery, was stented. One patient restenosed within 1 month of treatment. The remaining treated arteries remained patent during follow-up of 3 months to 2 years. Stroke as a complication occurred in 2 patients, 1 mild and 1 severe. There was no mortality. CONCLUSIONS: Occlusive arteriosclerotic disease involving the intracranial cerebral vessels can be managed medically with antiplatelet and anticoagulant drug therapy or surgically. However, in patients who are unresponsive to medical therapy or who have unacceptable surgical risks, percutaneous transluminal angioplasty is an attractive alternative that can be performed in selected patients with relatively low risk and good clinical outcome.

Adult↗

Endovascular treatment of paraclinoid aneurysms.

BACKGROUND: Paraclinoid aneurysms include those that are distal to the cavernous segment of the internal carotid artery and proximal to the posterior communicating artery. The purpose of this study was to review our experience with the endovascular treatment of this group of aneurysms, which are difficult to treat surgically. METHODS: Between June 1994 and April 1999, 66 patients (56 female, 10 male) with a mean age of 50.1 years (range 13-75, median 51) underwent endovascular treatment for 71 paraclinoid aneurysms. The mean size of the dome was 8.9 mm (range 3-25 mm, median 7) and the of neck was 3.8 mm (range 1.4-8 mm, median 4). Thirteen patients presented with acute subarachnoid hemorrhage, and 4 with previous subarachnoid hemorrhage. Six aneurysms produced mass effect with visual symptoms, 4 presented with transient ischemic attacks, and 44 were incidental. Nine patients had had previous unsuccessful surgery. All procedures were performed under general anesthesia and with systemic heparinization. RESULTS: Ninety endovascular procedures were performed on 71 aneurysms: GDC coiling in 78 (including 45 with the remodeling technique), permanent balloon occlusion in 9, and 3 had both GDC coiling and permanent balloon occlusion. In ten aneurysms it was not possible to place coils in the lumen of the aneurysm with the available technology and balloon occlusion was not indicated. Five of these were treated surgically and 5 remain untreated. All patients had immediate post procedure angiography. Of the 61 aneurysms that were treated, 46 (75%) have angiographic follow-up of 6 months or more. Morphological outcome following endovascular therapy for 61 aneurysms at last available follow-up showed > 95% occlusion in 52/61 (85.2%) and <95% in 9/61 (14.8%). Eight patients required surgery, 2 for partial coiling, 2 for refilling of a neck remnant, 2 for persistent mass effect and 2 for coil protrusion. In the 90 procedures performed, 2 (2.2%) patients had major permanent deficits (1 monocular blindness, 1 hemiparesis), 1 (1.1%) had a minor visual field cut, and 2 (2.2%) patients died from major embolic events. CONCLUSION: Properly selected paraclinoid aneurysms can be successfully treated by endovascular technology. The morbidity and mortality rate of the endovascular approach in our experience is equal to or better than the published surgical series of similar aneurysms. We recommend that the endovascular approach be given primary consideration in the treatment of paraclinoid aneurysms.

Adolescent↗

Role of magnetic resonance imaging and diagnostic and interventional angiography in vascular and neoplastic diseases of the skull base associated with vestibulocochlear symptoms.

There are many vascular and neoplastic diseases as well as normal variants that produce the vestibulocochlear symptoms of pulsatile tinnitus, hearing loss, dizziness, and ataxia. Magnetic resonance imaging may be diagnostic, and magnetic resonance angiography/magnetic resonance venography have added to the ability of magnetic resonance to image vascular abnormalities. The extent of neoplasms is accurately assessed and complication of vascular lesions are clearly seen. However, detailed vascular anatomy requires high-quality selective angiography. This enables optimal treatment planning. Endovascular therapeutic intervention has a major role to play in conjunction with surgery of skull base lesions and may be curative in certain conditions, avoiding major surgical procedures. The interventionalist, however, must have an excellent knowledge of the external carotid circulation and all of its potential communications with the internal circulation to avoid serious embolic complications.

Angiography↗

Arteriovenous malformation of the forehead, anterior scalp, and nasal dorsum.

Management of complex and relentless large arteriovenous malformations with long term control and acceptable aesthetic results can be accomplished. This outcome requires selective intra-arterial embolization, judicious surgical resection, composite reconstruction with free tissue transfer, other ancillary procedures, or both, and careful serial follow-up examinations to rule out recurrent or persistent disease.

Adult↗

The remodeling technique of balloon-assisted Guglielmi detachable coil placement in wide-necked aneurysms: experience at the University of Illinois at Chicago.

OBJECT: Reports in the literature have offered discussions of the feasibility, efficacy, and safety of balloon-assisted Guglielmi detachable coil (GDC) placement in wide-necked intracranial aneurysms, which was first described by Jacques Moret as the "remodeling technique." In this article the authors summarize their results in a subset of aneurysms treated with GDCs using the remodeling technique. METHODS: This report contains a retrospective analysis of 72 patients with 75 aneurysms who underwent 79 endovascular procedures performed using the remodeling technique. Morphological outcome was determined at the end of each procedure and by reviewing available follow-up angiograms. Clinical assessments and outcomes are reported using a modified Glasgow Outcome Scale. Coils were placed in 66 (88%) of 75 aneurysms selected for treatment. In eight aneurysms (11%) treatment failures occurred due to the tortuosity of the vessel used to reach the aneurysms or because of balloon inadequacies. Incorporating all available follow-up data the authors found that 50 (78%) of 64 aneurysms were completely or subtotally (> 95%) occluded and eight (12%) of 64 were incompletely (< 95%) occluded. Since the time of coil placement, eight aneurysms have progressed to complete occlusion and another five have exhibited progressive thrombosis on follow-up angiograms. In three aneurysms there has been neck remnant growth. Surgical clipping was performed to treat six aneurysms after an initial coil placement procedure. Permanent incidences of morbidity were limited to four patients and there were three deaths directly related to the procedure. CONCLUSIONS: The remodeling technique shows promise in increasing the number of cerebral aneurysms amenable to treatment by endovascular coil placement, and offers an alternative approach to aneurysms that have met with failed surgical treatment or are surgically inaccessible. Long-term follow-up review is needed to determine the final outcome of aneurysms treated by this technique.

Adult↗

[The sitting position in neurosurgery: the viewpoint of the surgeon].

The sitting position offers the benefits of better access to the apex of the posterior fossa, and an improved exploration and dissection because blood and cerebral spinal fluid drain away from the operative site. Specific complications of the sitting position include cardiovascular instability, jugular venous obstruction, airway oedema, quadriplegia, displacements of catheters and the endotracheal tube, ulnar, sciatic and lateral peroneal nerve compression, venous air embolism, and tension pneumocephalus. In the only existing comparative study, the differences were an increased bleeding in the horizontal position and a better cranial nerve preservation in the sitting position. This argues strongly for teaching and use of the sitting position whenever surgically indicated.

Humans↗

Neurovascular flow simulation review.

Computer simulation of the cerebral circulation has been carried out for three decades. We review the developments of cerebral circulation computer models of the last 30 years. Existing models are discussed in terms of fluid dynamics and possible clinical usage. Also the status and new achievements in some related research areas are summarized. Any new achievements in such areas would contribute to the progress of building a better model. A patient specific, highly predictive and reflective model could be a powerful clinical tool which would greatly benefit neurosurgeons and patients.

Arterial Occlusive Diseases↗

Selection of cerebral aneurysms for treatment using Guglielmi detachable coils: the preliminary University of Illinois at Chicago experience.

OBJECTIVE: We present our initial experience with Guglielmi detachable coils (GDCs). The aim of this study was to determine the criteria for aneurysms, ruptured or unruptured, that are suitable for this technique. The importance of aneurysm geometry and its impact on the final results are discussed. METHODS: A retrospective analysis of 329 patients with 339 cerebral aneurysms that were treated at the University of Illinois Hospital at Chicago from May 1994 to June 1997 was conducted. One hundred eighty-five patients were treated surgically, and 144 were selected for treatment using GDCs. Of the 144 patients selected for GDC treatment, 55 patients with 55 aneurysms were admitted during the acute phase of subarachnoid hemorrhage and 89 patients with 97 aneurysms had nonruptured aneurysms or were treated after clinical recovery of previously ruptured aneurysms. All procedures were performed with the patients under general anesthesia and with systemic heparinization using live simultaneous biplane roadmapping, with the exception of the first four patients. These patients were treated before the installation of the biplane system. The percentage of aneurysm occlusion was determined at the end of each procedure. Follow-up angiography was scheduled to be performed at 6 months, 1 year, and 2 years after treatment. PATIENT SELECTION: For the initial 25 patients (Group 1), selection for coiling was restricted to nonsurgical candidates or patients in whom coiling was thought to be the best treatment choice, based on medical condition and location of the aneurysm. The geometry of the aneurysm was not considered to be an important factor in the selection for coiling. The remaining patients (Group 2) were selected for coiling based on aneurysm geometry, as determined by pretherapeutic angiography. Aneurysms that were considered to be favorable for coiling included those that had a dome-to-neck ratio of at least 2 and an absolute neck diameter less than 5 mm. RESULTS: The initial 25 patients (Group 1) were treated from May 1994 to February 1995. There were high morbidity and mortality rates, with 56% of the treated aneurysms occluded at 6 months. The remaining patients (Group 2) consisted of 119 patients with 123 aneurysms. There was no mortality directly related to the coiling procedure, and permanent morbidity was limited to 1.0%. Three patients (2.5%) developed transient neurological deficits secondary to the procedure, and seven patients (5.8%) experienced periprocedural complications that did not result in neurological sequelae. The morphological results were strongly correlated to the geometry of the aneurysms, with a complete occlusion rate of 72% among the acutely ruptured aneurysms and 80% among the nonacute aneurysms, when patients were selected for treatment based on the geometry of the aneurysms and the dome-to-neck ratio was at least 2. The occlusion rate dropped to 53% when selection was not based on aneurysm geometry and the dome-to-neck ratio was less than 2. A summary of the morphological outcomes for the Group 2 patients shows that 86% of the aneurysms that initially underwent coiling using GDCs were completely occluded (78% by coils alone, 3.0% in conjunction with surgery, and 5.0% with parent artery occlusion). Residual small neck remnants were present in 11% of the Group 2 aneurysms (3.0% were scheduled for surgical treatment of residual neck remnant growths not amenable to further endovascular treatment, and 8% were scheduled for initial 6-mo follow-up examinations). Death resulting from unrelated causes before initial follow-up occurred in 3.0% of the patients. CONCLUSION: These preliminary results suggest that using GDCs is a safe technique resulting in low morbidity and mortality rates for the treatment of intracranial aneurysms in appropriately selected patients. The percentage of complete aneurysm occlusion is related to the density of coil packing, which is strongly dependent on the geometry of the aneurysm. Optim

Acute Disease↗

Aneurysm geometry: an important criterion in selecting patients for Guglielmi detachable coiling.

The study was aimed determine the criteria for treating cerebral aneurysms, ruptured and unruptured, suitable for endovascular Guglielmi detachable coiling (GDC) with least morbidity and mortality. We will discuss the importance of knowledge of the geometry of cerebral aneurysm and its impact on the results of coiling. We have treated 324 patients with cerebral aneurysms at the University of Illinois Hospital from May 1, 1994 to June 1997. During this period 139 patients were treated with GDC and 185 patients were treated surgically. Of 139 patients treated with coils 54 patients with 54 aneurysms were ruptured and the remaining 85 patients with 90 aneurysms were unruptured. For initial 25 patients, the selection of aneurysms for coiling was random and the geometry of the aneurysm was not considered as an important factor in the selection for coiling, however, in the later series of 114 patients with 119 aneurysms were selected for coiling only when the geometry looked favorable in the angiogram. With time we realized that the dome/neck ratio more than or equal to 2/1 and the diameter of the neck not exceeding 5 mm were most suitable for coiling. The initial series of 25 patients (May 1994 to February 1995) treated without taking geometry of the aneurysms as an important criteria for coiling led to high morbidity and mortality and less than 50% of these aneurysms were angiographically occluded at 6-month follow-up. In the second series of 114 patients (March 1995 to June 1997) with 119 aneurysms we had 0% mortality related to the coiling and only 1.8% permanent morbidity. We found complete aneurysm occlusion in 78% of the subarachnoid hemorrhage and 76% of unruptured group when the dome/neck ratio was more than or equal to 2/1. However, the occlusion rate dropped to 50% when the dome/neck ratio was less than 2/1. This preliminary experience suggests that GDC is a safe technique with low mortality-morbidity for the treatment of intracranial aneurysms in appropriately selected patients. The percentage of complete occlusion of the aneurysm following tight and dense packing is strongly dependent on the geometry of the aneurysm and we conclude that the best results are achieved when the dome/neck ratio is more than or equal to 2/1.

Adult↗

Normalization of transcranial Doppler middle cerebral artery velocities after aneurysm clipping.

BACKGROUND: Factors that promote normalization of middle cerebral artery (MCA) velocities after cerebral aneurysm surgery may be important to identify in order to optimize management. Survival analysis of serial transcranial Doppler (TCD) MCA velocities in the setting of aneurysm surgery offers an additional means of analyzing outcome. METHODS: We retrospectively studied serial MCA velocities obtained via TCD in 113 patients who underwent cerebral aneurysm clipping to analyze which factors promoted normalization. The presence of bleeding, aneurysm location, age, gender, ethnicity, initial blood pressure, hemoglobin, and clinical condition were examined. RESULTS: Patients who did not bleed but were clipped still tended to have transient periods of abnormally elevated velocities. Of those patients who bled and were clipped, older patients normalized faster. Women showed a trend toward slower normalization only in the subarachnoid hemorrhage (SAH) absent group. Other parameters listed above did not effect normalization time. CONCLUSIONS: Our data suggest aneurysm surgery in and of itself may promote transient rises in MCA velocities. Age appears to be a significant factor in predicting normalization of MCA velocities after SAH.

Adult↗

Embolization of the nidus of brain arteriovenous malformations with n-butyl cyanoacrylate.

OBJECTIVE: To demonstrate that nidus embolization of brain arteriovenous malformations (AVMs) with Histoacryl (B. Braun, Melsungen, Germany) is effective and yields low morbidity and mortality rates. METHODS: We present a retrospective analysis of 54 brain AVMs treated at the University of Illinois at Chicago from April 1994 to December 1995. Treatment modalities included embolization in all cases and then surgical resection or radiosurgery. INSTRUMENTATION: The nidus was reached with the combined use of a Magic microcatheter (Balt, Montmorency, France) and a Terumo 0.010-inch guidewire. TECHNIQUE: Embolization was performed only when the tip of the microcatheter was wedged into the nidus of the AVMs with no reflux of contrast proximally. The embolization was performed using simultaneous biplane roadmapping with the patient under general anesthesia without Amytal testing. RESULTS: Twenty-six of 54 patients are still waiting for more radical treatment. Two deaths and two minor and one severe permanent neurological deficit occurred. Three patients were cured with embolization alone; 11 patients were cured after surgical resection. Three patients underwent radiosurgery, with one cure after 1 year. CONCLUSION: Nidus embolization with Histoacryl is an effective technique that permits complete cure of a large number of brain AVMs, with or without surgical resection and/or radiosurgery.

Adolescent↗

Arteriovenous malformation nidus catheterization with hydrophilic wire and flow-directed catheter.

Arteriovenous malformation nidus catheterization with a flow-directed catheter at times can be difficult owing to tortuosity of the intracranial vasculature and distal location of the nidus. Since January 1995, hydrophilic wire has been used in conjunction with the 1.8F flow-directed microcatheter in over 150 vessel embolizations with cyanoacrylate glue for brain and spinal arteriovenous malformations at our institution. This technique has improved our success rate in achieving superselective catheterization of the nidus and has shortened the overall procedure time. To date, only one complication has occurred that was directly related to wire manipulation.

Adult↗

Desmoplastic infantile astrocytoma with metastases at presentation.

A 4-month-old child presented with nystagmus and macrocephaly. He had a large tumor in the suprasellar and hypothalamic region, as well as two smaller similar masses in the posterior fossa and one in the spinal canal. A biopsy of the suprasellar mass revealed it to be a desmoplastic infantile cerebral astrocytoma. Cerebrospinal fluid obtained at surgery before tumor manipulation showed clusters of malignant cells immunopositive for glial fibrillary acidic protein. In our opinion, the smaller tumors were metastases from the large suprasellar primary astrocytoma. Review of all of the previously reported cases of desmoplastic infantile cerebral astrocytoma and of the related neoplastic entity desmoplastic infantile ganglioglioma suggested that this was a unique case, but we still recommend caution with respect to the previously accepted notion that desmoplastic infantile neuroepithelial tumors are virtually benign neoplasms.

Astrocytoma↗