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Biomedical subjects

D M Pelz

Publications and source records attributed to D M Pelz.

At least 19 recordsLinked to original sources
PubMed2003

Combined endovascular/neurosurgical therapy of blister-like distal internal carotid aneurysms.

OBJECTIVE: To describe a novel therapeutic strategy for the treatment of "blister-like" aneurysms of the distal internal carotid artery (ICA). Direct surgical treatments of these fragile lesions have been associated with generally poor outcomes. METHODS: Two consecutive patients presenting with acute subarachnoid hemorrhage from "blister-like" aneurysms were treated with preliminary balloon occlusion of the ICA, followed by surgical trapping of the ICA beyond the aneurysm. RESULTS: The treatment resulted in complete thrombosis of both aneurysms with no clinical complications. CONCLUSION: This combined endovascular-neurosurgical approach offers a controlled, safer alternative to primary surgical therapy of "blister-like" aneurysms.

Adult↗
PubMed2002

Carotid stenting without angioplasty.

BACKGROUND: Carotid angioplasty and stenting is gaining popularity as an alternative to carotid endarterectomy for the treatment of carotid bifurcation stenosis. The major concern with the procedure is the risk of embolic stroke which may be initiated by balloon angioplasty of friable atherosclerotic plaque. Elimination of angioplasty may result in a lower incidence of embolic complications. METHOD: We describe a case in which a self-expanding stent alone, without balloon angioplasty, was used to successfully dilate an atherosclerotic stenosis of the carotid bifurcation. RESULTS: A moderate increase in vessel diameter, from 75% to 50%, was immediately observed after stent placement alone. No embolic complications were observed and follow-up plain film and ultrasound examinations showed progressive stent enlargement with excellent anatomic and hemodynamic results. CONCLUSIONS: In this case of severe carotid stenosis, the use of a self-expanding stent alone, without balloon angioplasty, resulted in excellent anatomic and hemodynamic improvement.

Aged↗
PubMed2000

Carotid angioplasty and stenting: current status.

Carotid angioplasty and stenting has recently emerged as a popular alternative to endarterectomy for the treatment of carotid atherosclerosis. Carotid endarterectomy has been scientifically validated, but many believe carotid angioplasty and stenting to be a less invasive, less expensive and equally safe and effective method of treatment. The evidence for and against the use of each procedure will be discussed.

Angioplasty↗
PubMed2000

Clinical presentation and management of giant anterior communicating artery region aneurysms.

OBJECT: The authors reviewed their 20-year experience with giant anterior communicating artery aneurysms to correlate aneurysm size with clinical presentation and to analyze treatment methods. METHODS: In 18 patients, visual and cognitive impairment were quantitated and clinical outcome was categorized according to the Rankin scale. Statistical analysis was performed using Fisher's exact test. CONCLUSIONS: At least 3.5 cm of aneurysm mass effect was required to produce dementia in the patient (p = 0.0004). Dementia was usually caused by direct brain compression by the aneurysm rather than by hydrocephalus. Optic apparatus compression occurred with smaller aneurysms (2.7-3.2 cm) when they pointed inferiorly. Aneurysm neck clipping was possible in half of the cases. Special techniques, including temporary clipping, evacuation of intraluminal thrombus, tandem and/or fenestrated clipping, and clip reconstruction were often required. Occlusion of or injury to the anterior cerebral artery (ACA) was the main cause of poor outcome or death. Proximal ACA occlusion, even of dominant A1 segments with small or no contralateral A1 artery, was an effective treatment alternative and was well tolerated as a result of excellent leptomeningeal collateral circulation.

Adult↗
PubMed2000

Endovascular therapy of a large vertebral artery aneurysm using stent and coils.

BACKGROUND: Endovascular therapy is becoming an increasingly popular treatment for cerebral aneurysms. Total angiographic occlusion of small-necked aneurysms (<4 mm) can be obtained in a high percentage of cases. The endovascular treatment of wide-necked or fusiform aneurysms remains a challenge with complete angiographic occlusion reported in <15% of cases. CASE REPORT: We describe the combined use of a flexible coronary stent and platinum coils to treat a wide-necked aneurysm of the distal left vertebral artery, in a patient with Grade IV subarachnoid hemorrhage. RESULTS: The procedure was technically successful as the parent artery was protected by the stent while coils were deposited in the aneurysm lumen. Although angiographic aneurysm occlusion was incomplete, the dome was packed with coils. No further hemorrhage has occurred. CONCLUSION: Combined endovascular stent and coil therapy is a promising technique for the treatment of wide-necked cerebral aneurysms.

Cerebral Angiography↗
PubMed1998

Thromboembolic events associated with the treatment of cerebral aneurysms with Guglielmi detachable coils.

BACKGROUND AND PURPOSE: The purpose of this study was to document the prevalence, radiologic appearance, and treatment of thromboembolic events related to GDC embolization of cerebral aneurysms. METHODS: The clinical and radiologic records of all patients undergoing GDC treatment of intracranial aneurysms at our institution were reviewed. All cases in which unexpected complications occurred were selected. Those complications related to presumed thromboembolic events were analyzed. RESULTS: Of 59 patients (60 aneurysms) treated with GDCs, 17 (28%) experienced thromboembolic events. Seven patients had transient ischemic attacks and 10 had strokes. In 10 patients, the deficits occurred during or immediately after the procedure; in the rest, the complications were delayed. In six patients, all radiologic investigations were negative for infarction and in seven patients, CT scans showed new ischemic lesions. In four patients, MR imaging alone showed infarcts, and in four of nine patients who underwent subsequent angiography, acute ischemic findings were demonstrated. Eight patients were treated with volume expansion, eight with full heparinization, and one patient underwent intraarterial thrombolysis. Clinical outcome was excellent or good in 14 of 17 patients, with only three patients (5%) incurring permanent neurologic deficits. CONCLUSION: Thromboembolic events related to GDC treatment may be more common than has been reported in the literature. In our experience, this rate was 28%, with persisting deficits in 5%. These events can occur after uncomplicated procedures and may be unaccompanied by radiologic findings. Clinical outcome is usually favorable.

Adult↗
PubMed1997

Intracranial dural arteriovenous fistulae with pial venous drainage: combined endovascular-neurosurgical therapy.

BACKGROUND: Intracranial dural arteriovenous fistula with pial venous drainage may present with hemorrhage or focal neurologic deficit and may be difficult to treat. We wish to summarize the therapeutic approaches to these potentially dangerous lesions and to demonstrate how endovascular and neurosurgical therapies may have complimentary roles in their management. METHODS: The clinical and radiological records of all patients who presented to our institution with intracranial dural arteriovenous fistula over the last 5 years were reviewed. In those cases demonstrating pial venous drainage, details of presentation, imaging features, endovascular and surgical therapy and outcome were analyzed. RESULTS: We identified 13 patients with these lesions, 7 of whom presented with intracranial hemorrhage. Six patients were treated with embolization alone. Angiographic cure was achieved in 4. There was one complication in this group, a subarachnoid hemorrhage following glue injection. Four patients were treated with embolization followed by surgical occlusion of the pial venous drainage. Angiographic cure was achieved in all 4. There was one complication in this group, a facial nerve palsy following glue injection. Three patients were treated by surgery alone, with no complications and complete cure in all. CONCLUSION: Endovascular therapy of intracranial dural arteriovenous fistula may be curative but is often complex and carries definite risks. Neurosurgical ligation of pial draining veins, with pre-operative embolization when safe, may be a relatively more controlled method to achieve complete cure.

Adult↗
PubMed1997

Comparison of the Bullard and Macintosh laryngoscopes for endotracheal intubation of patients with a potential cervical spine injury.

BACKGROUND: In the emergency trauma situation, in-line stabilization (ILS) of the cervical spine is used to reduce head and neck extension during laryngoscopy. The Bullard laryngoscope may result in less cervical spine movement than the Macintosh laryngoscope. The aim of this study was to compare cervical spine extension (measured radiographically) and time to intubation with the Bullard and Macintosh laryngoscopes during a simulated emergency with cervical spine precautions taken. METHODS: Twenty-nine patients requiring general anesthesia and endotracheal intubation were studied. Patients were placed on a rigid board and anesthesia was induced. Laryngoscopy was performed on four occasions: with the Bullard and Macintosh laryngoscopes both with and without manual ILS. Cricoid pressure was applied with ILS. To determine cervical spine extension, radiographs were exposed before and during laryngoscopy. Times to intubation and grade view of the larynx were also compared. RESULTS: Cervical spine extension (occiput-C5) was greatest with the Macintosh laryngoscope (25.9 degrees +/- 2.8 degrees). Extension was reduced when using the Macintosh laryngoscope with ILS (12.9 +/- 2.1 degrees) and the Bullard laryngoscope without stabilization (12.6 +/- 1.8 degrees; P < 0.05). Times to intubation were similar for the Macintosh laryngoscope with ILS (20.3 +/- 12.8 s) and for the Bullard without ILS (25.6 +/- 10.4 s). Manual ILS with the Bullard laryngoscope results in further reduction in cervical spine extension (5.6 +/- 1.5 degrees) but prolongs time to intubation (40.3 +/- 19.5 s; P < 0.05). CONCLUSIONS: Cervical spine extension and time to intubation are similar for the Macintosh laryngoscope with ILS and the Bullard laryngoscope without ILS. However, time to intubation is significantly prolonged when the Bullard laryngoscope is used in a simulated emergency with cervical spine precautions taken. This suggests that the Bullard laryngoscope may be a useful adjunct to intubation of patients with potential cervical spine injury when time to intubation is not critical.

Adult↗
PubMed1996

Central pontine myelinolysis and cyclosporine neurotoxicity following liver transplantation.

In a recent series of 44 liver transplants we identified both extrapontine myelinolysis (EPM) - characteristic of cyclosporine neurotoxicity - and central pontine myelinolysis (CPM) in 5 recipients posttransplant. An additional 2 recipients had EPM only posttransplant. MRIs performed in 4 asymptomatic recipients were normal. Large perioperative shifts in serum sodium, hypomagnesemia, and high cyclosporine levels may play a role in the development of these lesions, although the evidence from this study is inconclusive. In addition to supportive care, dilantin was started in patients who had seizures; aggressive magnesium replacement was initiated for hypomagnesemia, and cyclosporine levels were reduced in all patients. All patients demonstrated a slow steady recovery and all but 2 are at home at the time of writing. CPM may be more prevalent than previously appreciated following liver transplantation, although its prognosis may not be as dismal.

Adult↗
PubMed1996

Duplex and color Doppler flow sonography of occlusion and near occlusion of the carotid artery.

PURPOSE: To determine whether color Doppler flow imaging with the use of slow-flow sensitivity improves sensitivity and specificity in the differentiation of occlusion and near occlusion of the internal carotid artery. METHODS: Color Doppler and duplex sonography were performed in symptomatic patients who had angiographically confirmed occlusion and/or near occlusion of the internal carotid artery. The study consisted of two phases: in the first, we assessed the usefulness of color Doppler flow imaging by retrospectively reviewing the records of 35 patients with 36 angiographically confirmed occlusions or near occlusions of the internal carotid artery who were examined with color Doppler flow imaging at our institution during a period of 4 years; in the second phase, we incorporated color Doppler sonography into the routine scanning protocols of 39 patients with 41 occluded or nearly occluded internal carotid arteries seen over a period of 2 1/2 years. RESULTS: Overall, color Doppler imaging correctly showed all 34 of the near occlusions (sensitivity, 100%) and 36 of the 43 occlusions (specificity, 84%). Seven patients with angiographically confirmed occlusion had sonographic findings that suggested near occlusion. In the first phase, eight near occlusions were misinterpreted as occlusions with conventional duplex sonography, but were correctly shown with color Doppler flow imaging. In the second phase, sensitivity increased from 50% to 100% (18 or 18) because of better detection of the nearly occluded lumen. This was at the expense of a decrease in specificity (from 100% to 78%). owing to identification of apparent flow in the internal carotid artery on color Doppler flow images in five of 23 occlusions. CONCLUSION: Because of its ability to depict slow flow, color Doppler imaging with slow-flow sensitivity is superior to conventional duplex sonography for the noninvasive discrimination of occlusion from near occlusion of the internal carotid artery.

Arterial Occlusive Diseases↗
PubMed1995

Therapeutic embolization in the treatment of intractable epistaxis.

OBJECTIVE: To determine the effectiveness of therapeutic embolization in the treatment of intractable epistaxis. DESIGN: Cohort. SETTING: Tertiary care hospital. PATIENTS: Consecutive referred sample of 57 patients with intractable epistaxis. INTERVENTION: Percutaneous transfemoral catheterization and angiography of the internal maxillary arteries. Embolization of the most distal branches with 0.1- to 0.9- cm3 medium-sized polyvinyl alcohol particles on the suspected side of bleeding. OUTCOME: Outcome was successful if no further interventional treatment was required for epistaxis. RESULTS: Anatomical abnormalities precluded embolization in three patients. Three of the remaining 54 patients required supplementry embolization. Including these three patients, 52 (96%) of 54 patients had successful control epistaxis. The major neurologic complication rate was 6% (three of 54 patients), with no permanent deficits. CONCLUSIONS: Therapeutic embolization is an effective and safe technique and should be considered as the primary treatment modality in severe epistaxis.

Adolescent↗
PubMed1995

Interventional neuroradiology.

Interventional neuroradiology is a dynamic subspecialty which is rapidly gaining new applications in the treatment of neurological diseases. The most common therapeutic role is still in the treatment of brain AVMs, aneurysms and fistulae in close association with neurosurgical support. Endovascular treatment of aneurysms with thrombogenic coils is a promising technique which can be performed with low morbidity. The goal of complete aneurysm occlusion, including the neck, has not yet been achieved in all cases and the procedure has not been shown to possess clear advantages over surgical clipping. Pre-operative embolization of tumours and spinal lesions are common procedures in some centres. Angioplasty and papaverine infusion for treatment of cerebral vasospasm are being performed in most neurosurgical teaching centres. Although angiographic results are often impressive, corresponding clinical improvement is not always seen, particularly when treatment is delayed. Thrombolysis for treatment of acute stroke and angioplasty for treatment of cerebrovascular atherosclerosis are new techniques which await scientific validation before being accepted as standard therapies.

Angioplasty, Balloon↗
PubMed1995

Magnetic resonance imaging of brain death.

OBJECTIVE: To demonstrate the magnetic resonance imaging (MRI) appearance of the brain in patients with clinical brain death. PATIENTS AND METHODS: High-field (1.5-T) MRI was performed on five patients who were subsequently proven clinically brain dead. Conventional T1-weighted and T2-weighted imaging was performed. RESULTS: MRI exhibited similar features for all of the patients: loss of the subarachnoid spaces of the brain; slow flow in the intracavernous and cervical internal carotid arteries; and loss of flow void in the small and large intracranial arteries, as well as in the major intracranial venous sinuses. The differentiation between grey and white matter in the brain was preserved, although the brain had a "supernormal" appearance due to the absence of cerebrospinal fluid and arterial pulsations. These findings have not been observed in MRI of comatose patients who were not clinically brain dead. CONCLUSION: With the advent of MRI-compatible ventilators and noninvasive monitoring, which facilitate imaging of patients under intensive care, MRI may offer another method of confirming the clinical diagnosis of brain death.

Adolescent↗
PubMed1995

Symptomatic pulmonary complications from liquid acrylate embolization of brain arteriovenous malformations.

PURPOSE: To describe symptomatic pulmonary emboli from brain arteriovenous malformation embolization with liquid acrylates and to analyze the reasons for these complications and describe preventive techniques. METHODS: The clinical records of 182 patients embolized with acrylate glue since 1978 for treatment of brain AVMs were searched for evidence of symptomatic pulmonary complications. Originally iso-butyl-2-cyanoacrylate and more recently n-butyl-2-cyanoacrylate were used in all patients. Arteriovenous malformation morphology, amounts and techniques of glue injection, and clinical and radiologic investigations in the symptomatic patients were recorded. RESULTS: Three patients had pulmonary symptoms within 48 hours of glue injection. One patient with a left frontal arteriovenous malformation had embolization with an isobutyl-2-cyanoacrylate/pantopaque/acetic acid mixture; severe pleuritic chest pain developed 2 days later. One patient with a left temporal and one with a left cerebellar arteriovenous malformation had embolization with n-butyl-2-cyanoacrylate/lipiodol mixtures; a cough, pleuritic chest pain, and bloody sputum developed in both within 24 hours. Two patients experienced a significant drop in PO2. No flow-arrest techniques were used for any of the injections in these three patients. All patients demonstrated significant changes on chest x-ray and CT chest examinations. All were treated conservatively and recovered spontaneously. CONCLUSIONS: Symptomatic pulmonary complications can occur after acrylate glue injection, particularly when delivery systems without flow arrest are used in high-flow vascular brain lesions. Techniques using acetic acid to delay polymerization time and "sandwich" techniques in which glue is pushed with dextrose are also more susceptible to this complication.

Acetates↗