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Biomedical subjects

C F Dowd

Publications and source records attributed to C F Dowd.

At least 19 recordsLinked to original sources
PubMed2005

Long-term outcome of endovascular stenting for symptomatic basilar artery stenosis.

Eighteen patients underwent stenting for symptomatic basilar artery stenosis. There were three major periprocedural complications (16.7%) without fatality. At a mean 26.7 +/- 12.1-month follow-up, 15 patients (83.3%) had an excellent long-term outcome. Only one patient (5.6%) had moderate disability from recurrent stroke, and two patients died of medical illness at 30 and 36 months after stenting. In this uncontrolled study, stenting appeared to be effective in reducing stroke risk and death and worthy of further scrupulous trial.

Aged↗
PubMed2003

Neurodevelopmental outcome after endovascular treatment of vein of Galen malformations.

OBJECTIVE: To assess neurodevelopmental outcome after endovascular treatment of vein of Galen malformations (VOGM). METHODS: Outcome of patients who underwent endovascular treatment for VOGM between 1983 and 2002 was assessed by chart review and parental questionnaires. Development was classified as normal, minor delay (slow initial acquisition of milestones but no permanent disability), or significant delay (slow or incomplete acquisition of milestones with some permanent disability) using an adaptation of the Denver Developmental Questionnaire. RESULTS: Twenty-seven patients were identified: five presented prenatally (by ultrasound), 16 as neonates, and 6 after the neonatal period. The most common presenting features were congestive heart failure (CHF; 16/27) and hydrocephalus (8/27). The 16 patients with CHF all presented either prenatally or neonatally; 4 died acutely, 6 had significant delay, and 6 had no or minor developmental delay. Of those presenting in the perinatal period without CHF, all survived, two of five were significantly delayed, and three of five had no delay. Of those presenting after the neonatal period, all survived and only one of six had delay. By angiographic classification, outcome was worse for those with choroidal VOGM (3/13 died; 5/13 had significant delay) than for those with mural VOGM (2/10 had significant delay; none died). For the entire series, 52% of all cases (61% of survivors) had no or minor delay. CONCLUSIONS: Fourteen of 27 children who received treatment for VOGM had a favorable outcome. Features associated with worse outcome were perinatal presentation, presence of CHF, and choroidal angioarchitecture.

Cardiovascular Abnormalities↗
PubMed2001

The many faces of PHACE syndrome.

OBJECTIVES: PHACE is an acronym coined to describe a neurocutaneous syndrome encompassing the following features: posterior fossa brain malformations, large facial hemangiomas, arterial anomalies, cardiac anomalies and aortic coarctation, and eye abnormalities. We evaluated the spectrum of disease and significance of potential underlying brain anomalies among affected children. STUDY DESIGN: The records of 14 patients with PHACE syndrome, evaluated between 1995 and 2000, were retrospectively reviewed. A literature review revealed 116 additional cases. RESULTS: PHACE syndrome represents a spectrum of anomalies, because most affected children have only one extracutaneous manifestation. The syndrome is associated with a high incidence of arterial and structural central nervous system anomalies with secondary neurologic sequelae. The potential for progressive neurovascular disease also exists among those patients with anomalous vasculature. CONCLUSION: PHACE syndrome should be considered in any infant presenting with a large, segmental, plaque-type facial hemangioma. Children at risk should receive careful ophthalmologic, cardiac, and neurologic assessment.

Abnormalities, Multiple↗
PubMed2001

Endovascular treatment of a ruptured dual aperture cavernous aneurysm.

The authors describe the diagnosis and endovascular management of a multiaperture, ruptured cavernous internal carotid artery aneurysm causing a carotid cavernous fistula (CCF) using both transarterial and transvenous techniques. Although uncommon, recognition of the imaging characteristics of such a lesion will aide in successful management and improve treatment outcome. To the authors' knowledge, CCF due to a ruptured cavernous aneurysm with multiple shunts has not been previously reported.

Aneurysm, Ruptured↗
PubMed2001

Dural arteriovenous fistula associated with prothrombin gene mutation.

An association between dural arteriovenous fistula and cerebral sinus thrombosis is reported. It is clear in several cases that thrombosis precedes the development of the fistula while it is unclear that it occurs in every case. The authors report a case of a woman with sinus thrombosis and presence of prothrombin gene mutation who subsequently developed a large dural arteriovenous fistula. Various possible factors involved in the pathogenesis of a dural fistula are discussed, with emphasis on underlying thrombophilia and oral contraceptive use in this patient.

Adult↗
PubMed2000

Endovascular and surgical treatment of unruptured cerebral aneurysms: comparison of risks.

Unruptured cerebral aneurysms are commonly treated by surgical clipping, but endovascular coil embolization is increasingly employed as an alternative. In a blinded review of unruptured aneurysms treated at our institution since 1990, we identified patients whose aneurysms were judged to be treatable by both neurosurgeons and neurointerventional radiologists. A change in Rankin Scale score of 2 or more from hospital admission to discharge, indicating a new moderate disability or worse, was predefined as the primary outcome measure. Long-term follow-up was obtained by mailed questionnaire and telephone interview. Length of stay and hospital charges were totaled for all hospitalizations, including follow-up. Sixty-eight patients treated surgically and 62 patients treated with endovascular coil embolization were considered candidates for either procedure on blinded review, and overall anticipated procedure risk was rated as identical. A larger proportion of patients in the surgical group developed a change in Rankin Scale score of 2 or more (25% of surgical patients vs 8% of endovascular patients). Total length of stay was longer (mean days: 7.7 for surgical patients vs 5.0 for endovascular patients) and hospital charges were greater (mean, $38,000 for surgical patients vs $33,400 for endovascular patients) for the surgical patients. At follow-up, an average of 3.9 years after the procedure, surgical patients were more likely to report persistent new symptoms or disability since treatment (34% of surgical patients vs 8% of endovascular patients) and a longer period for recovery to normal (50% returning to normal in 1 year for surgery and in 27 days for coil embolization). Coil embolization of unruptured cerebral aneurysms seems to be associated with significantly fewer complications than surgical clipping. More long-term data on aneurysm rupture rates are required to confirm efficacy.

Adult↗
PubMed2000

Balloon tracheal occlusion for congenital diaphragmatic hernia: experimental studies.

PURPOSE: Temporary tracheal occlusion is an effective strategy to enlarge fetal lungs, but the optimal technique to accomplish occlusion is unknown. External clips are effective when applied fetoscopically (Fetendo clip), but require a difficult fetal neck dissection. This study was undertaken to assess the feasibility of intratracheal balloon occlusion, revisiting the internal occlusion strategy. METHODS: (1) The internal diameter (ID) of human fetal trachea (53 fetuses; 14 to 41 weeks' gestation) was compared using a computer-assisted image analyzer and sonography, ex vivo. (2) Volume to diameter relationship of the balloon (balloon configuration curve) was defined using an image analyzing computer. (3) Using the trachea of fetal sheep, pressures that break balloon tracheal seal (seal pressure) were investigated. RESULTS: (1) Between 16 and 41 weeks' gestation, tracheal ID (range, 0.7 to 5.4 mm) correlates significantly with gestational age. (2) Balloon volume required to achieve tracheal seal could be determined based on the tracheal growth curve and the balloon configuration curve. (3) Tracheal seal breaking points varied depending on the tracheal specimen tested. CONCLUSION: Internal tracheal occlusion using a balloon is feasible with minimal tracheal damage if the balloon volume is adjusted to fetal tracheal growth.

Balloon Occlusion↗
PubMed2000

Role of angiography in the evaluation of patients with pulsatile tinnitus.

OBJECTIVES/HYPOTHESIS: Pulsatile tinnitus in the face of normal findings on otoscopy is a common otological diagnostic dilemma and can be due to serious vascular malformations such as transverse or sigmoid sinus dural arteriovenous fistula (transverse or sigmoid sinus [TS] DAVF). Left untreated, TS DAVF may result in significant morbidity and mortality. TS DAVF can be suspected or diagnosed with computed tomography (CT), magnetic resonance imaging (MRI), and magnetic resonance angiography (MRA), with the gold standard being angiography. Our objective was to assess the utility of these various diagnostic modalities in the diagnosis of dural arteriovenous fistula. STUDY DESIGN: Retrospective clinical review. METHODS: Between 1986 and 1996, 54 patients were evaluated and treated for TS DAVF. Between 1996 and 1999, an additional 33 patients underwent MRI combined with MRA for the evaluation of pulsatile tinnitus. A retrospective review of the medical records for both groups, with special attention to clinical presentation, diagnostic evaluation, therapy, and outcome, was performed. RESULTS: All patients had pulsatile tinnitus with normal findings on otoscopy. CT scan was relatively insensitive in the detection of TS DAVF. MRI and MR/MRA were significantly more sensitive than CT. In the evaluation of patients with subjective pulsatile tinnitus, MRI/MRA defined anatomical abnormalities that may contribute to pulsatile tinnitus in 63% of patients. CONCLUSIONS: In the absence of objective pulsatile tinnitus, MRI/MRA is an appropriate initial diagnostic step. When a patient has an objective bruit, the clinician may choose to proceed directly to angiography to make certain that a TS DAVF is not missed.

Adult↗
PubMed2000

Balloon-assist technique for endovascular coil embolization of geometrically difficult intracranial aneurysms.

OBJECTIVE: The balloon-assist or neck-remodeling technique is an adjunctive method devised for the endovascular coil embolization of aneurysms characterized by a wide neck or unfavorable geometric features. Since its initial description, there have been few data to corroborate its utility, efficacy, and safety in aneurysm embolization. METHODS: Twenty patients (19 female patients and 1 male patient) with 22 aneurysms (19 unruptured aneurysms and 3 ruptured aneurysms) underwent balloon-assisted coil embolization. The balloon-assist technique was performed in the same treatment session after conventional coil embolization had failed in 55% of cases (12 of 22 cases) and was the primary treatment in 45% of cases. The majority of aneurysms were located in the supraclinoid carotid artery (13 paraophthalmic and 3 superior hypophyseal aneurysms). The mean angiographic measurements included a fundus of 8.7 +/- 3.7 mm, a neck of 5.3 +/- 2.2 mm, and a comparatively unfavorable fundus/neck ratio of 1.33 +/- 0.23. RESULTS: Technical success was achieved in 77% of cases (17 of 22). The rate of aneurysm obliteration at the end of the procedures was 97 +/- 3.8%. Angiographic follow-up data (mean follow-up period, 10.3 mo) obtained for 89% of the treated aneurysms (15 of 17) confirmed stable mean occlusion of 97.8 +/- 3.8%. Technical complications included two cases of asymptomatic distal vessel thromboembolism, which resolved angiographically within 24 hours, and one case of intraprocedural rupture of an arteriovenous malformation-related feeder artery aneurysm, which resulted in no neurological deficits and required no further treatment (transient complication rate, 13.6%; 3 of 22 cases). There were no deaths and no procedure-related 30-day or permanent morbidity. CONCLUSION: The balloon-assist method of coil embolization is characterized by promising intermediate-term angiographic and clinical outcomes and acceptable morbidity and mortality rates. Although this adjunctive method requires the use of an additional microcatheter and consequently involves a higher level of technical complexity, it extends the range of aneurysms that can be successfully treated with electrolytically detachable coils via an endovascular approach.

Adult↗
PubMed2000

Stent-supported coil embolization: the treatment of fusiform and wide-neck aneurysms and pseudoaneurysms.

OBJECTIVE: We describe a consecutive series of patients treated with endovascular stent-supported coil embolization for symptomatic or enlarging wide-neck and fusiform aneurysms and pseudoaneurysms of the carotid and vertebrobasilar arteries. METHODS: Seven stent-supported coil embolization procedures were performed for seven aneurysms in seven consecutive patients. There were five pseudoaneurysms, one dissecting aneurysm, and one berry aneurysm. Four aneurysms were located in the carotid artery, and three were located in the vertebrobasilar system. Three aneurysms were intracranial. Four patients were symptomatic, and three had angiographic evidence of increasing aneurysm size. RESULTS: Technical success was achieved in six (86%) of seven patients. Entanglement of a coil with the stent struts necessitated partial coil delivery into the parent artery in one patient, but there were no neurological or other adverse sequelae. The 30-day rate of periprocedural stroke or mortality was 0%. At a mean clinical follow-up of 14.5 months, neurological status was at baseline or better in all patients. To date, all treated patients remain clinically asymptomatic with oral administration of aspirin only. CONCLUSION: Stent-supported coil embolization represents an emerging therapeutic alternative to surgery for the treatment of symptomatic or enlarging wide-neck and fusiform aneurysms and pseudoaneurysms of the cervical and vertebrobasilar arteries, which are not amenable to conventional unsupported coil embolization. Experience with greater numbers of patients and long-term follow-up are required to further validate this technique.

Adult↗
PubMed2000

Cerebral hyperperfusion syndrome after percutaneous transluminal stenting of the craniocervical arteries.

OBJECTIVE: Cerebral hyperperfusion syndrome is a recognized complication of carotid endarterectomy, with a reported incidence of 0.3 to 1.2%. The incidence of cerebral hyperperfusion after endovascular revascularization procedures of the craniocervical arteries remains unknown. We evaluated the incidence of cerebral hyperperfusion syndrome in our endovascular revascularization series. To our knowledge, there are no previous studies evaluating the incidence of hyperperfusion syndrome after percutaneous transluminal angioplasty/stenting. METHODS: Between March 1996 and February 2000, 140 patients underwent percutaneous transluminal angioplasty/stenting of the craniocervical arteries at our institution. In all patients, selective bilateral arteriography of the carotid and vertebral arteries was performed to document the sites of craniocervical stenosis and collateral blood flow and the results of the endovascular revascularization procedure. We then reviewed all pertinent medical records, arteriographic films, and sectional imaging studies to determine the incidence of cerebral hyperperfusion in this series. RESULTS: Seven patients (5.0%) developed clinical or radiological manifestations of cerebral hyperperfusion. In the target group, percutaneous transluminal stenting achieved a 90 to 100% reduction in stenotic lesions (mean stenosis, 91%) of the carotid (n = 5) and vertebral (n = 2) arteries. All seven patients remained neurologically stable immediately after treatment. There was delayed development of clinical and radiographic findings, suggestive of cerebral hyperperfusion. Six patients showed evidence of ipsilateral hemispheric edema, including two patients who developed intracranial hemorrhage (one parenchymal, one parenchymal and subarachnoid) documented by computed tomographic brain scans. Symptoms resolved within 72 hours in the four patients without hemorrhage. The two patients with hemorrhage recovered during a more protracted period (range, 3 wk to 6 mo). There were no long-term sequelae or deaths during a cumulative follow-up of 84 months (mean follow-up, 12 mo). CONCLUSION: Hyperperfusion syndrome is an uncommon but potentially serious complication of extracranial and intracranial angioplasty and stenting procedures. The clinical manifestations are similar to hyperperfusion syndrome after carotid endarterectomy; however, the prevalence may be greater in the high-risk cohort commonly referred for endovascular treatment. Our findings suggest that patients undergoing endovascular stenting procedures should be closely monitored for evidence of hyperperfusion, with careful monitoring of blood pressure, heart rate, and anticoagulation. Further research is needed to confirm that cerebral hyperperfusion is the pathogenesis of this condition.

Aged↗
PubMed2000

Carotid artery stent placement for atherosclerotic disease: rationale, technique, and current status.

Carotid arterial endarterectomy is considered to be the standard for the treatment of atherosclerotic carotid arterial occlusive disease. This has been validated with results of several randomized controlled trials in which its effectiveness has been demonstrated over that of the best nonsurgical therapy. In the past several years, however, carotid angioplasty with stent placement has emerged as a potential alternative to carotid endarterectomy. This article represents a critical examination of the rationale for carotid revascularization; the history of endovascular techniques for the treatment of carotid atherosclerosis, beginning with balloon angioplasty and evolving to the use of stents; and the evidence supporting the effectiveness of the endovascular approach. A brief description of the current technical aspects of carotid artery stent placement is presented. The future status of the endovascular approach will be determined with randomized trials in which carotid artery stent placement is directly compared with endarterectomy, as well as by the potential for further innovation and improvement in endovascular devices, technique, and safety.

Angioplasty↗
PubMed2000

Endovascular treatment of ruptured posterior circulation cerebral aneurysms. Clinical and angiographic outcomes.

BACKGROUND AND PURPOSE: We sought to describe the clinical outcome and angiographic results obtained in the endovascular therapy of ruptured posterior circulation cerebral aneurysms using Guglielmi detachable coils (GDC) over a 7-year period. METHODS: A retrospective analysis was performed of 112 patients evaluated at the University of California at San Francisco Medical Center between June 1991 and August 1998. The Hunt-Hess grade at presentation of treated patients was I in 26 patients (24%), II in 24 (22%), III in 27 (25%), IV in 24 (22%), and V in 8 (7%). Clinical follow-up for the total population was achieved in 104 of 109 patients (96%), with a mean duration of 13.1 months. Angiographic follow-up for the subset excluding parent vessel occlusion cases was obtained in 93% of cases, with a mean duration of 7.2 months. RESULTS: Technical success, defined as the ability to catheterize and embolize the aneurysm with GDC, was achieved in 109 of 112 of cases (97%). The mean angiographic occlusion rate, or projected area of the aneurysm occluded by the coils, for all 110 successfully treated aneurysms was 94.6%. At latest clinical follow-up, 81 of 109 patients (74%) achieved good recovery with Glasgow Outcome Scale (GOS) score of I, 10 of 109 (9%) were moderately (GOS II) and 5 of 109 (5%) were severely (GOS III) disabled, 1 of 109 (1%) remained in a vegetative state (GOS IV), and 12 of 109 (11%) were dead. Of the subset of 77 patients with Hunt-Hess grades I to III, 68 (88%) achieved a good clinical outcome (GOS I). A statistically significant correlation was demonstrated between Hunt-Hess grade at presentation and final GOS outcome score (chi(2)=41.4, P<0.0005). Procedure-related permanent morbidity was 2.8% (3/109 patients). Repeated hemorrhage was observed in a single patient (0.9%) with a partially treated aneurysm. CONCLUSIONS: The observed favorable outcome and low morbidity in this group of high-risk patients point to GDC embolization as an effective method for the endovascular management of patients with ruptured posterior circulation aneurysms.

Adolescent↗
PubMed2000

Stent angioplasty for cervical carotid artery stenosis in high-risk symptomatic NASCET-ineligible patients.

BACKGROUND AND PURPOSE: Although the North American Symptomatic Carotid Endarterectomy Trial (NASCET) has shown carotid endarterectomy (CEA) to be protective compared with medical therapy alone, its stringent eligibility criteria excluded patients with severe medical, angiographic, and neurological risk factors. We sought to determine the safety and efficacy of stent angioplasty in this high-risk subset for whom the perioperative morbidity and mortality of surgery are elevated. METHODS: Twenty-eight consecutive symptomatic NASCET-ineligible patients (10 female; median age, 72.2 years) underwent microcatheter-based carotid stent angioplasty. Half of the patients had sustained a previous stroke. Classification of surgical risk by Sundt criteria yielded no patients in grade 1, 3 patients in grade 2 (10.7%), 8 in grade 3 (28.6%), and 17 (60.7%) in grade 4. Stratification of stroke risk for medical therapy according to the European Carotid Surgery Trial (ECST) 5-point score showed 8 patients with a score of 3 (28.6%), 12 with 4 (42.8%), and 8 with 5 (28.6%). Follow-up was obtained in all patients at a median of 14 months. RESULTS: The procedure was technically successful in all cases (100%), with immediate stenosis reduction from a mean of 80.3% to 2.7%. There were no periprocedural deaths, 1 major stroke (3.6%), no minor strokes, and 3 transient ischemic attacks (10.7%). In-hospital complications included 2 nonfatal myocardial infarctions, 1 case of acute renal failure, and 1 groin hematoma requiring transfusion. There were 5 deaths during the follow-up period, all beyond 30 days after the procedure: 3 from cardiac causes, 1 from lung cancer, and 1 following unrelated surgery. The patient with major stroke died at 7.8 months during rehabilitation. No surviving patients had further strokes, and all except 1 (95.5%) remained asymptomatic. Anatomic follow-up in 20 patients showed occlusion in 2 (10%) (1 symptomatic, 1 asymptomatic) and intimal hyperplasia in 3 asymptomatic patients (15%). CONCLUSIONS: The clinical results and sustained freedom from symptoms and stroke during the short available follow-up period suggest that stent angioplasty may be useful in the treatment of symptomatic cervical carotid stenosis in high-risk patients despite a notable incidence of restenosis.

Aged↗
PubMed2000

Patient presentation, angiographic features, and treatment of strangulation-induced bilateral dissection of the cervical internal carotid artery. Report of three cases.

Domestic violence leading to strangulation by an abusive spouse can cause carotid artery dissection. This phenomenon is rare and has been described in only three previous instances. The authors present their management strategies in three additional cases. Three young women aged 24 to 43 years were victims of manual strangulation committed by their spouses 3 months to 1 year before presentation. Two of the patients suffered delayed cerebral infarctions before presentation and angiography demonstrated focal, mirror-image severe residual stenoses in the high-cervical internal carotid artery (ICA), which were characteristic of a healed chronic dissection; there was no evidence of fibromuscular dysplasia. One of these patients underwent unilateral percutaneous angioplasty with stent placement, and the other underwent bilateral percutaneous angioplasty. Both patients have recovered from their strokes and remain clinically stable at 8 and 20 months posttreatment, respectively. The third patient presented with bilateral ischemic frontal watershed infarctions resulting from an occluded left ICA and a severely narrowed right ICA. Given the extent of the established infarctions, this case was managed with a long-term regimen of anticoagulation medications, and the patient remains neurologically impaired. These cases illustrate the susceptibility of the manually compressed ICA to traumatic injury as a result of domestic violence. They identify bilateral symmetrical ICA dissection as a consistent finding and the real danger of delayed stroke as a consequence of strangulation. Endovascular therapy in which percutaneous angioplasty and/or stent placement are used can be useful in treating residual focal stenoses to improve cerebral perfusion and to lower the risk of embolic or ischemic stroke.

Adult↗