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Colin P Derdeyn

Publications and source records attributed to Colin P Derdeyn.

At least 37 records · Page 2Linked to original sources
PubMed2005

Absent relationship between the coil-embolization ratio in small aneurysms treated with a single detachable coil and outcomes.

BACKGROUND AND PURPOSE: Although attenuated coil packing of intracranial aneurysms is an important goal of endovascular embolization, because of their small size, some aneurysms can only be treated with a single embolization coil. We retrospectively analyzed small aneurysms treated with a single Guglielmi detachable coil (GDC) to determine whether the coil-embolization ratio (CER) is predictive of embolization stability. METHODS: The CER was determined for 25 small (<7-mm diameter) intracranial aneurysms, each treated with a single embolization coil. The largest aneurysm dimension, estimated by comparison to anatomic landmarks, was used for volume calculation based on a spherical model. Coil volumes were according to manufacturer specifications. CER was calculated by the formula (coil volume/aneurysm volume) x 100%. Embolization stability was assessed by angiographic follow-up. RESULTS: The average CER for all aneurysms was 8.2% (SD, 6.5%; range, 0.6%-21.1%). Twelve percent of the aneurysms had a CER >20%. Follow-up angiographic assessment was conducted at an average of 30.8 months after initial treatment. Eighty-four percent of the aneurysms were obliterated. One large (6 x 10 mm) and 3 small (<1 mm) recurrences were identified. The average CER for unchanged aneurysms was 8.0% (SD, 5.9%) and for the recurrent aneurysms was 8.8% (SD, 8.7%), which was not statistically significant. CONCLUSION: Small aneurysms treated with a single coil achieved satisfactory stability despite having a low average packing attenuation. CER was not predictive of recurrence in small intracranial aneurysms treated with a single detachable coil.

Adult↗
PubMed2005

Angioplasty and stenting in carotid dissection with or without associated pseudoaneurysm.

BACKGROUND AND PURPOSE: Carotid angioplasty and stent placement may be the preferred treatment in patients with carotid dissection who have failed medical management. The goal of this study was to determine the procedural feasibility and safety as well as long-term complication rates of carotid angioplasty and stent placement in a consecutive cohort of relatively young, high-surgical-risk patients. PATIENTS AND TECHNIQUES: A series of 26 consecutive patients (mean age, 49 years; 15 men and 11 women) who underwent angioplasty and stent placement for carotid dissection with or without pseudoaneurysm from April 1997 to April 2005 at our institution (9 traumatic, 8 spontaneous, and 9 iatrogenic) was retrospectively reviewed. Twenty-eight stents were used in 29 procedures performed on 27 vessels (20 internal carotid arteries and 7 common carotid arteries). Patients were followed with cerebral angiography, CT, sonography, or clinically for a mean of 14.6 months (range, 5 days to 48.2 months) with 17 of 26 patients having at least 6 months of follow-up. Procedural and long-term complication rates were calculated. RESULTS: Dissection-induced stenosis was reduced from 71 +/- 18% to no significant stenosis in 20 of the 21 patients with measurable stenosis. The procedural transient ischemic attack (TIA) rate was 3 of 29 procedures (10.3%). There were no procedural strokes. One patient required angioplasty of a common femoral artery. One procedure was terminated when an asymptomatic new intimal flap was created before intervention. Two patients had occlusions of the treated vessel noted at 22 days (presented with contralateral stroke) and 3.4 months (asymptomatic). There were 2 unrelated deaths from myocardial infarction at 8 days and 15.2 months. Two patients had recurrent ipsilateral TIA at 2.7 months and 12 months. The 30-day occlusion and death rate was 2 of 29 procedures (6.9%). CONCLUSION: In this series, angioplasty and stent placement were effective in relieving stenosis secondary to carotid dissection with or without pseudoaneurysm and have low rates of ischemic complications.

Adult↗
PubMed2004

Primary angiitis of the central nervous system at conventional angiography.

PURPOSE: To retrospectively determine the sensitivity and specificity of cerebral angiography for the diagnosis of primary angiitis of the central nervous system (CNS). MATERIALS AND METHODS: Institutional review board approval was obtained, and informed consent was not required. Thirty-eight patients (13 men, 25 women; mean age, 55 years) had undergone cerebral angiography followed by cortical and leptomeningeal biopsy for possible primary angiitis of the CNS during an 8-year period. Angiography reports were reviewed by investigators blinded to the results of biopsy. Angiographic findings were categorized as typical for vasculitis, normal, or other. Sensitivity and specificity of cerebral angiography for the diagnosis of primary angiitis of the CNS were calculated. RESULTS: Fourteen patients had typical angiographic findings of vasculitis. None had primary angiitis of the CNS at brain biopsy (60% specificity). Specific pathologic diagnoses other than primary angiitis of the CNS were made in six patients. Findings of brain biopsy in the remaining eight patients were nondiagnostic. Repeat angiograms were obtained in three of the eight patients. One patient demonstrated interval improvement in multiple focal intracranial arterial stenoses and two demonstrated worsening. Primary angiitis of the CNS was found at biopsy in two of the remaining 24 patients (0% sensitivity). One of the two patients had slow filling of a single distal cortical artery, and the other patient had multiple regions of abnormally prolonged capillary blush. CONCLUSION: In this series, patients suspected of having primary angiitis of the CNS on the basis of clinical and angiographic findings did not have primary angiitis of the CNS at biopsy. Typical angiographic findings of primary angiitis of the CNS are often associated with other specific pathologic diagnoses, which emphasizes the importance of brain biopsy.

Adult↗
PubMed2004

Histologic and hemodynamic effects of endosaccular platinum coils for intracranial aneurysms.

Over the past 15 years, endosaccular platinum coil therapy for intracranial aneurysms has evolved from clinical pilot studies of investigational devices to common clinical practice. The mechanism by which these coils reduce the risk of aneurysm rupture-the primary goal of intracranial aneurysm treatment-is the focus of this review. Both histological mechanisms of scar formation and hemodynamic mechanisms of flow diversion may be involved. We will first review aneurysm epidemiology to provide the context and rationale for therapy for patients harboring intracranial aneurysms. Next, we will review the data for and theories of the pathophysiology of aneurysm formation, growth, and rupture, particularly as they relate to endovascular coil therapy. Histological and hemodynamic studies of coiled aneurysms in animals and humans will be reviewed. Finally, we will discuss emerging coil-based therapies, such as bioactive polymer coatings for platinum coils and the adjunctive use of stents.

Aneurysm, Ruptured↗
PubMed2004

MR safety and imaging of neuroform stents at 3T.

The Neuroform stent is a self-expanding nitinol stent designed for use in wide-necked intracranial aneurysms. Heating and imaging artifacts were evaluated by using a porcine carotid artery aneurysm model in a 3T MR system. A suspended Neuroform stent was tested for deflection. No heating was measured, and no evidence of deflection of the stent was found. Imaging artifacts were minimal. MR imaging in patients with Neuroform stent-treated aneurysms is safe and feasible.

Alloys↗
PubMed2003

The Carotid Occlusion Surgery Study.

The St. Louis Carotid Occlusion Study demonstrated that ipsilateral increased O2 extraction fraction (OEF) (Stage II hemodynamic failure) measured by positron emission tomography (PET) is a powerful independent risk factor for subsequent stroke in patients with symptomatic complete carotid artery (CA) occlusion. The ipsilateral ischemic stroke rate at 2 years has been shown to be 5.3% in 42 patients with normal OEF and 26.5% in 39 patients with increased OEF (p = 0.004). In patients in whom hemispheric symptoms developed within 120 days, the 2-year ipsilateral stroke rates were 12% in 27 patients with normal OEF and 50% in 18 patients with increased OEF. Previous PET studies have demonstrated that anastomosis of the superficial temporal artery (STA) to a middle cerebral artery (MCA) cortical branch can restore OEF to normal. The authors discuss the undertaking of a study that will test the hypothesis that STA-MCA anastomosis, when combined with the best medical therapy, can reduce ipsilateral ischemic stroke by 40% at 2 years in patients with symptomatic internal CA occlusion and Stage II hemodynamic failure occurring within 120 days after surgery. Only patients with increased OEF distal to a symptomatic occluded CA will be randomized to surgery or medical treatment. The primary endpoint will be all strokes and death occurring between randomization and the 30-day postoperative cut off (with an equivalent period in the nonsurgical group), as well as subsequent ipsilateral ischemic stroke developing within 2 years. It is estimated that 186 patients will be required in each group. Assuming that 40% of PET scans will demonstrate increased OEF, this will require enrolling 930 clinically eligible individuals.

Anticoagulants↗
PubMed2003

Mortality rates after subarachnoid hemorrhage: variations according to hospital case volume in 18 states.

OBJECT: The goal of this study was to determine whether a hospital's volume of subarachnoid hemorrhage (SAH) cases affects mortality rates in patients with SAH. For certain serious illnesses and surgical procedures, outcome has been associated with hospital case volume. Subarachnoid hemorrhage, usually resulting from a ruptured cerebral aneurysm, yields a high mortality rate. There has been no multistate study of a diverse set of hospitals to determine whether in-hospital mortality rates are influenced by hospital volume of SAH cases. METHODS: The authors conducted an analysis of a retrospective, administrative database of 16,399 hospitalizations for SAH (9290 admitted through emergency departments). These hospitalizations were from acute-care hospitals in 18 states representing 58% of the US population. Both univariate and multivariate analyses were used to assess the case volume-mortality rate relationship. The authors used patient age, sex, Medicaid status, hospital region, data source year, hospital case volume quartile, and a comorbidity index in multivariate generalized estimating equations to model the relationship between hospital volume and mortality rates after SAH. Patients with SAH who were treated in hospitals in which low volumes of patients with SAH are admitted through the emergency department had 1.4 times the odds of dying in the hospital (95% confidence interval 1.2-1.6) as patients admitted to high-volume hospitals after controlling for patient age, sex, Medicaid status, hospital region, database year, and comorbid conditions. CONCLUSIONS: Patients with a diagnosis of SAH on their discharge records who initially presented through the emergency department of a hospital with a high volume of SAH cases had significantly lower mortality rates. Concentrating care for this disease in high-volume SAH treatment centers may improve overall survival.

Adult↗
PubMed2003

Measurement of cerebral blood flow in chronic carotid occlusive disease: comparison of dynamic susceptibility contrast perfusion MR imaging with positron emission tomography.

BACKGROUND AND PURPOSE: Our purpose was to evaluate the accuracy of cerebral blood flow (CBF) measurements obtained by using dynamic susceptibility contrast-enhanced MR imaging, including the influence of arterial input function (AIF) selection, compared with those obtained by using [(15)O]-H(2)O positron emission tomography (PET) for patients with chronic carotid occlusion. METHODS: MR images and PET scans were obtained of seven patients with unilateral carotid occlusion and were co-registered for region of interest analysis. PET CBF maps were generated by using the autoradiographic method. MR imaging CBF maps were calculated by deconvolution of the susceptibility time curve with a proximal middle cerebral artery AIF and were converted to absolute flow rates either by assuming a constant contralateral white matter CBF value of 22 mL/100 mL/min or by using individually determined PET white matter CBF values. RESULTS: Although CBF values measured by PET and MR imaging were positively correlated for every patient, the slopes and y intercepts of the regression lines varied widely among patients. The correlation was better when individual white matter CBF values measured by PET were used to scale the white matter CBF values measured by MR imaging (r = 0.84, P <.0001) than when constant contralateral CBF values were assumed (r = 0.54, P <.0001). The choice of AIF ipsilateral or contralateral to the occluded carotid artery made no statistically significant difference (P >.05) to the correlation coefficient, slope, or y intercept of the MR imaging versus PET CBF regressions for six of the seven patients. CONCLUSION: Although linearly correlated with CBF values measured by PET, dynamic susceptibility contrast-enhanced MR imaging was not accurate for measuring absolute CBF values. AIF selection relative to the side of carotid occlusion did not significantly affect calculated MR imaging CBF values for six of the seven patients.

Aged↗
PubMed2003

Management of neuroform stent dislodgement and misplacement.

A self-expanding stent has recently been introduced for the treatment of wide-neck aneurysms. We describe two cases of stent malposition within large aneurysms. In the first case, the stent was dislodged during microcatheterization. This was managed by placement of a second stent through the interstices of the first followed by aneurysm coiling. In the second case, after deployment, the proximal portion of the stent moved into the aneurysm as the exchange guidewire was removed. This patient was treated by vessel sacrifice.

Adult↗
PubMed2002

Variability of cerebral blood volume and oxygen extraction: stages of cerebral haemodynamic impairment revisited.

The presence or degree of haemodynamic impairment due to occlusive cerebrovascular disease is often inferred from measurements of cerebral blood flow (CBF), cerebral blood volume (CBV), oxygen extraction fraction (OEF) and the cerebral rate for oxygen metabolism (CMRO2). However, the relationship of these variables, in particular CBV, to regional cerebral haemodynamics is not clearly established in humans with subacute or chronic disease. In the present study, we investigated the relationship of CBV to OEF, CBF and CMRO2, and to subsequent stroke risk in patients with unilateral carotid artery occlusion, in order to define better the associated haemodynamic and metabolic changes. We reviewed data from 81 patients with symptomatic carotid occlusion enrolled in a prospective study of haemodynamic factors and stroke risk. Measurements of CBV, CBF, OEF and CMRO2 were made on entry using PET. Patients were divided into groups by hemispheric ratios and absolute ipsilateral values of OEF and CBV, based on comparison with normal controls. Haemodynamic and metabolic values, risk factors and stroke risk were compared between groups. Based on hemispheric ratios, 45 patients had increased ipsilateral OEF; CBV was increased in 19 of these 45 patients. No differences in CBF, CMRO2 or clinical risk factors were found between these 19 patients and the remaining 26 patients with increased OEF and normal or reduced CBV. Thirteen ipsilateral strokes occurred during follow-up, and 10 of the 13 occurred in the 19 patients with increased OEF and CBV (log rank P < 0.0001). Thirty-two of the 68 patients with complete quantitative PET data had increased OEF by absolute ipsilateral values. CBV was increased in 20 of the 32 patients. No differences in CBF, CMRO2 or clinical risk factors were found between these 20 patients and the remaining 12 patients with increased OEF and normal CBV. Seven of the nine ipsilateral strokes that occurred in the 68 patients occurred in those 20 patients with increased OEF and increased CBV (log rank P = 0.003). The higher risk of ischaemic stroke in patients with increased OEF and CBV suggests that their degree of haemodynamic compromise is more severe than those with increased OEF and normal CBV. In patients with chronic carotid occlusion and increased OEF, increased CBV may indicate pronounced vasodilation due to exhausted autoregulatory vasodilation. The physiological explanation for the measurement of normal CBV in patients with increased OEF is less certain and may reflect preserved autoregulatory capacity.

Adult↗
PubMed2002

Long-term outcome after angioplasty for symptomatic extracranial carotid stenosis in poor surgical candidates.

BACKGROUND AND PURPOSE: The optimal treatment of patients with symptomatic carotid stenosis who are poor surgical candidates is uncertain. The purposes of this study were to report the long-term outcome after angioplasty in a series of these patients and to compare these data with historical control data from the North American Symptomatic Carotid Endarterectomy Trial (NASCET). METHODS: We identified 42 consecutive patients with >70% carotid stenosis and ipsilateral ischemic symptoms within 120 days of treatment with angioplasty. All were considered poor surgical candidates by experienced surgeons. Baseline epidemiological stroke risk factors were obtained from review of medical records. Follow-up was from clinic records and by telephone. RESULTS: Baseline epidemiological stroke risk factors were similar to those of medically treated NASCET patients. Angioplasty patients tended to have higher degrees of stenosis (45% with >90% stenosis versus 24% in NASCET) and more frequent contralateral stenosis or occlusion (30% versus 9%) than NASCET patients. Three patients suffered procedural strokes; 2 of the 3 made nearly complete recoveries. One additional patient suffered a central retinal occlusion 48 hours after angioplasty. No ipsilateral strokes occurred during the mean follow-up period of 1.7 years. Three patients were lost to follow-up. The cumulative risk of stroke was 9.5% (4 of 42) compared with 26% at 2 years for medically treated patients in NASCET. CONCLUSIONS: These pilot data suggest a beneficial effect of angioplasty for patients with high-grade symptomatic carotid stenosis who are not good surgical candidates.

Adult↗
PubMed2002

Postprocedure ischemic events after treatment of intracranial aneurysms with Guglielmi detachable coils.

OBJECT: Ischemic stroke or transient ischemic attack (TIA) may occur after the treatment of intracranial aneurysms with Guglielmi detachable coils (GDCs). The purpose of the present study is to investigate possible risk factors for thromboembolic events and to determine their frequency and time course. METHODS: The records of 178 consecutive patients with 193 treated intracranial saccular aneurysms were reviewed. A total of 159 GDC procedures were performed to treat 143 aneurysms in 133 of those patients who were in good neurological condition, allowing clinical detection of postprocedure ischemic events (TIA or stroke). The association of clinical, anatomical, and pharmacological factors with intraprocedure intraarterial thrombus and with postprocedure ischemic events was investigated by using uni- and multivariate analyses. Thrombus protruding into the parent artery was noted during six of 159 GDC procedures, resulting in a clinical deficit in one patient. No factor was associated with intraprocedure intraarterial thrombus. Ten postprocedure ischemic events occurred in nine patients. Seven events occurred within 24 hours, and three events occurred between 24 hours and 58 days. Aneurysm diameter and protruding coils were significant independent predictors of postprocedure ischemic events in multivariate analysis (both p = 0.02). The actuarial risk of stroke was 3.8%. CONCLUSIONS: Larger aneurysm diameter and protruding loops of coils are associated with postprocedure ischemic events after GDC placement. It is unlikely that GDC-treated aneurysms retain thromboembolic potential beyond 2 months.

Adult↗