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A J Ringer

Publications and source records attributed to A J Ringer.

10 recordsLinked to original sources
PubMed2001

Angioplasty for cerebral vasospasm from eclampsia.

BACKGROUND: Neurological deterioration in eclampsia is considered to be secondary to cerebral vasospasm. Magnesium sulfate therapy improves symptoms and controls seizures, possibly related to its vasorelaxive effects in spastic arteries. Some cases, however, are refractory to magnesium therapy. To our knowledge, there is no report of angioplasty for vasospasm from eclampsia in the literature. METHODS: A 27-year-old woman presented 10 days postpartum with severe mental status changes and left arm and bilateral leg weakness that were refractory to magnesium therapy. Cerebral angiography demonstrated diffuse, severe vasospasm. We treated her with angioplasty of the bilateral middle and posterior cerebral arteries, basilar artery, and bilateral internal carotid arteries. RESULTS: Angioplasty resulted in excellent angiographic improvement. The patient immediately became responsive and appropriate with improved strength in all extremities. She continued to improve throughout her hospital stay and was discharged 10 days postangioplasty. CONCLUSIONS: Cerebral angioplasty is an effective treatment for vasospasm from eclampsia refractory to magnesium therapy. Angiography should be considered early in the course of neurological deterioration, but delayed therapy may also be effective.

Adult↗
PubMed2001

Open-label phase I clinical study to assess the safety of intravenous eptifibatide in patients undergoing internal carotid artery angioplasty and stent placement.

OBJECTIVE: Eptifibatide, a competitive platelet glycoprotein IIb-IIIa receptor inhibitor with high selectivity and a short half-life, has been demonstrated to reduce the risk of ischemic events associated with coronary interventions. However, its role in neurointerventional procedures needs to be analyzed. We report the results of an open-label Phase I study to evaluate the safety of the use of eptifibatide during carotid angioplasty and stent placement. METHODS: Each study patient received eptifibatide administered intravenously as a 135-microg/kg single-dose bolus, then a 0.5-microg/kg/min infusion for 20 to 24 hours during carotid angioplasty and stent placement. The primary efficacy end point was the 30-day composite occurrence of death, cerebral infarction, transient ischemic attack, and unplanned or urgent surgical intervention, thrombolysis, or subsequent percutaneous revascularization. The primary safety end point was bleeding. Bleeding complications were classified as major (hemoglobin decrease >5 g/dl), minor (hemoglobin decrease 3-5 g/dl), or insignificant. RESULTS: Ten patients (mean age, 73 yr; four men) were treated by use of the study protocol. One patient developed a minor stroke postprocedurally (National Institutes of Health Stroke Scale score of 21 at 24 h that improved to 1 at 7 d). Three patients underwent scheduled coronary artery bypass graft surgery 4 to 12 days after undergoing carotid angioplasty and stent placement. At 1-month follow-up, no new ischemic events were observed. Major or minor bleeding was not observed in any patient. Insignificant bleeding was observed in two patients. CONCLUSION: The use of eptifibatide as an adjunct to carotid angioplasty and stent placement seems to be safe. Further studies are required to analyze the effectiveness and role of eptifibatide in neurointerventional procedures.

Aged↗
PubMed2001

Angioplasty of intracranial occlusion resistant to thrombolysis in acute ischemic stroke.

OBJECTIVE: Thrombolysis has been demonstrated to improve revascularization and outcome in patients with acute ischemic stroke. Many centers now apply thrombolytic therapy locally via intra-arterial infusion. One therapeutic benefit is the ability to cross soft clots with a guidewire and to perform mechanical thrombolysis. In some instances, reopened arteries reocclude as a result of either thrombosis or vasospasm. We report the use of balloon angioplasty during thrombolysis for acute stroke. METHODS: From June 1995 through June 1999, 49 patients underwent intra-arterial therapy for acute stroke. In this group, nine patients (seven men and two women) were treated with balloon angioplasty after inadequate recanalization with thrombolytic infusion. The mean age of these patients was 67.9 years. Nine matched control patients who underwent thrombolysis alone without angioplasty were chosen for comparison. RESULTS: In the group of nine patients who had angioplasty, the mean National Institutes of Health Stroke Scale score at presentation was 21.8 +/- 5.4. Four patients had residual distal occlusion after angioplasty, and one patient had a hemorrhagic conversion. Of the five patients in which recanalization was successful, none had reocclusion of the balloon-dilated vessel. The mean score at 30 days for the five survivors was 12.6 +/- 14.9, for an improvement of 7.0 +/- 14.2. Among the nine control patients, the mean score at presentation was 20.3 +/- 5.2; the mean score at 30 days for the five survivors was 19.4 +/- 7.7, for an improvement of 4.2 +/- 7.8. CONCLUSION: In our experience, balloon angioplasty is a safe, effective adjuvant therapy in patients who are resistant to intra-arterial thrombolysis. The use of balloon angioplasty may prevent reocclusion in a stenotic artery and permit distal infusion of thrombolytic agents.

Aged↗
PubMed2001

Intra-arterial third-generation recombinant tissue plasminogen activator (reteplase) for acute ischemic stroke.

OBJECTIVE: We prospectively evaluated the safety and recanalization efficacy of intra-arterially administered reteplase, a third-generation recombinant tissue plasminogen activator, for treating ischemic stroke in patients considered poor candidates for intravenously administered alteplase therapy. METHODS: Patients were considered poor candidates for intravenously administered therapy because of severity of neurological deficits, interval from onset of symptoms to presentation of 3 hours or more, or recent major surgery. We administered a maximum total dose of 8 U of reteplase intra-arterially in 1-U increments via superselective catheterization. Adjunctive angioplasty of the occluded artery was performed in seven patients. Angiographic evidence of perfusion and thrombus was graded by use of modified Thrombolysis in Myocardial Infarction (TIMI) criteria. Neurological examinations were performed before and 24 hours and 7 to 10 days after treatment. RESULTS: Sixteen consecutive patients were treated (mean age, 64.1 +/- 16.4 yr; seven were men). Initial National Institutes of Health Stroke Scale scores ranged from 10 to 26. Time from onset of symptoms to treatment ranged from 2 to 9 hours. Occlusion sites were the cervical internal carotid artery (n = 4), intracranial internal carotid artery (n = 4), middle cerebral artery (n = 6), and vertebrobasilar artery (n = 2). Complete or near-complete perfusion (TIMI Grade 3 or 4) was achieved in the arteries in 14 patients (88%), with partial recanalization (TIMI Grade 2) or minimal response (TIMI Grade 1) in the arteries in one patient each. Neurological improvement (defined as decrease of four or more points in National Institutes of Health Stroke Scale score) was observed in 7 (44%) of the 16 patients at 24 hours. Symptomatic intracerebral hemorrhage occurred in one patient; three other patients experienced intracerebral hemorrhages that did not result in neurological worsening. The overall mortality during hospitalization was 56%, related to massive ischemic stroke (n = 7), withdrawal of care at the family's request after the development of aspiration pneumonia and renal failure (n = 1), and a combination of intracerebral hemorrhage and massive ischemic stroke (n = 1). CONCLUSION: In this study, intra-arterially administered reteplase in doses up to 8 U with or without angioplasty resulted in a high rate of recanalization. This strategy should be considered in treating patients considered poor candidates for intravenous thrombolysis.

Acute Disease↗
PubMed2001

Role of conventional angiography in evaluation of patients with carotid artery stenosis demonstrated by Doppler ultrasound in general practice.

BACKGROUND AND PURPOSE: Previous studies have suggested that patients with carotid stenosis who are candidates for endarterectomy can be effectively identified on the basis of carotid Doppler ultrasound alone. Before widespread acceptance of this policy, the accuracy of carotid Doppler ultrasound outside selected centers and clinical trials needs to be evaluated. We performed a 12-month prospective study to evaluate the accuracy of Doppler ultrasound in identifying patients for carotid intervention in general practice settings. METHODS: Each patient referred to our endovascular service for diagnostic angiography to evaluate for carotid stenosis was interviewed and examined by a neurologist. Subjects consisted of symptomatic patients with >/=50% stenosis and asymptomatic patients with >/=60% stenosis by Doppler ultrasound. Information pertaining to demographic and cerebrovascular risk factors and the results of the carotid Doppler ultrasound were recorded. The severity of stenosis on angiograms was measured with North American Symptomatic Carotid Endarterectomy Trial criteria by a blinded observer. The results of both studies were compared to determine the relative accuracy of ultrasound results. RESULTS: Of 130 patients (mean age, 69+/-8.8 years) who met Doppler ultrasound criteria, 22 (17%) and 8 patients (6%) were found to have 30% to 49% or <30% stenosis by angiography, respectively. The positive predictive value of carotid Doppler ultrasound for identifying appropriate symptomatic candidates for carotid intervention (angiographic stenosis >/=50%) was 80%, with a false-positive value of 20%. The positive predictive value of carotid Doppler ultrasound for identifying appropriate asymptomatic candidates for carotid intervention (angiographic stenosis >/=60%) was 59%, with a false-positive value of 41%. Carotid endarterectomy or angioplasty and stent placement were undertaken subsequently in 60 (46%) of the patients. In 94 patients who underwent cerebral angiography alone, no complications were observed. CONCLUSIONS: The present accuracy of carotid Doppler ultrasound in general practice does not justify its use as the sole basis of selecting appropriate patients for carotid intervention. Given the relatively low rate of associated morbidity with present day techniques, additional confirmatory studies such as angiography should be performed in every patient before a decision regarding intervention is made.

Aged↗
PubMed2001

Endovascular treatment of intracranial aneurysms by using Guglielmi detachable coils in awake patients: safety and feasibility.

OBJECT: Embolization of intracranial aneurysms performed using Guglielmi detachable coils (GDCs) is performed with the patient in a state of general anesthesia at most centers. Such an approach does not allow intraprocedural evaluation of the patient's neurological status and carries additional risks associated with general anesthesia and mechanical ventilation. At the authors' institution, GDC embolization of intracranial aneurysms is performed in awake patients after administration of sedative and analgesic agents (midazolam, fentanyl, morphine, and/or hydromorphone). To determine the feasibility and safety of this approach, the authors have retrospectively reviewed their clinical experience. METHODS: The authors reviewed the medical records of all patients in whom GDC embolization for the treatment of intracranial aneurysms was undertaken between February 1, 1990 and October 31, 1999. Clinical presentation, medical comorbidities, anesthetic agents used, intraprocedural complications, and final procedural outcome were recorded for each patient. Guglielmi detachable coil embolization was attempted in the awake patient in 150 procedures. Among 92 procedures for unruptured aneurysms, 75 (82%) were completed without complications. Four procedures were completed with complications. Of the 92 procedures, 13 were aborted due to patient uncooperativeness (one patient), complications (three patients), morphological characteristics of the aneurysm or surrounding vessels that made embolization technically difficult (eight patients), or vasospasm (one patient). Among 58 procedures for ruptured aneurysms, the procedure was completed without complication in 48 cases (83%). The procedure was completed with complications in five cases and two patients required induction of general anesthesia during the procedure. Five procedures were aborted because morphological characteristics of the aneurysm or surrounding vessels made embolization technically difficult (two patients) or because of aneurysm rupture (two patients) or the appearance of a transient neurological deficit (one patient). CONCLUSIONS: Embolization of intracranial aneurysms performed using GDCs in the awake patient appears to be safe and feasible and allows intraprocedural evaluation of the patient. Potential advantages, including decreased cardiopulmonary morbidity rates, shorter hospital stay, and lower hospital costs, still require confirmation by a direct comparison with other anesthetic procedures.

Adult↗
PubMed2000

Horner's syndrome after carotid artery stenting: case report.

BACKGROUND: Angioplasty and stenting of various lesions of the carotid artery is gaining in popularity. Our knowledge of the efficacy and limitations of this promising technology is incomplete. Although Horner's syndrome and its variants have been described after traumatic, spontaneous, or surgical carotid dissection, it has not been reported after carotid artery stenting. CASE DESCRIPTION: A 36-year-old woman presented with left neck and ear pain and a 3-year history of rushing noises in her left ear. Angiography demonstrated evidence of dissection of the left internal carotid artery at the skull base with a pseudoaneurysm. The pseudoaneurysm was treated with a 6-mm diameter self-expanding stent in a 4-mm diameter left internal carotid artery. A few hours later, she developed partial Horner's syndrome with a subtle ipsilateral ptosis and miosis without anhidrosis. Angiography performed on the next day did not demonstrate further dissection or aneurysm growth but did show distention of the artery wall because of the stent. She did not develop any further sequelae. CONCLUSION: This case suggests that stretching of the artery wall may result in stretching of surrounding structures. The sympathetic fibers surrounding the internal carotid artery are clearly sensitive to this degree of stretch. Possible complications associated with stretch injury must be considered when choosing the stent diameter.

Adult↗
PubMed2000

Intracranial stent placement to trap an extruded coil during endovascular aneurysm treatment: technical note.

OBJECTIVE: The development of low profile, navigable stents has expanded the range of intracranial neuroendovascular procedures. We report a unique case of endovascular stent placement to trap a partially extruded Guglielmi detachable coil (GDC) during treatment of an internal carotid artery (ICA) cavernous segment aneurysm. METHODS: A 49-year-old woman presented for endovascular coiling of a left superior hypophyseal artery aneurysm. Previously, a contralateral mirror lesion had been treated by stent-assisted coiling. Heparin was administered to maintain an activated coagulation time of greater than 250 seconds, and a guide catheter was placed in the cervical ICA. A microcatheter was advanced into the aneurysm over a microguidewire. A GDC-10, 3-dimension, 6 x 20-mm coil was placed within the aneurysm, forming a stable basket. Three additional GDCs were placed with near-complete obliteration of the aneurysm. Attempted placement of a fifth coil caused partial prolapse of a previously placed coil into the cavernous ICA. We decided to place a stent rather than to snare the extruded coil because the extruded coil was integral to the aneurysm coil mass. A 3.5x8-mm balloon-expandable stent was placed across the aneurysm orifice, trapping the extruded coil between the stent and ICA. RESULTS: Digital subtraction angiography documented patency of the ICA lumen. The patient remains neurologically intact and awaits 3-month follow-up cerebral angiography. CONCLUSION: Trapping of an extruded intraaneurysmal coil via stent placement obviated the need for coil removal and avoided the risk of coil mass manipulation. The use of a stent to displace extruded coils and reconstitute a "normal" lumen is an excellent addition to our endovascular armamentarium.

Carotid Artery, Internal↗
PubMed2000

Intraarterial recombinant tissue plasminogen activator for ischemic stroke: an accelerating dosing regimen.

OBJECTIVE: Urokinase has been conventionally used for intraarterial thrombolysis in acute ischemic stroke. Recently, due to the withdrawal of urokinase from the market, attention has been focused on recombinant tissue plasminogen activator (r-tPA) for intraarterial administration. Data is limited regarding the intraarterial dose, efficacy, and safety profile of this agent. METHODS: We prospectively studied 8 consecutive patients with acute ischemic stroke who were referred for intraarterial lysis. Each patient was considered by the treating neurologist to be a poor candidate for intravenous therapy. We administered a maximum total dose of 40 mg of r-tPA intraarterially via superselective catheterization. Angiograms were obtained after each 10 mg of r-tPA, and responses were graded using modified Thrombolysis in Myocardial Infarction (TIMI) criteria for perfusion and degree of thrombus. RESULTS: Initial National Institutes of Health Stroke Scale (NIHSS) scores ranged from 16 to 21. Intervals from presentation to treatment initiation ranged from 1 to 8 hours. After administration of r-tPA, neurological improvement (decrease in NIHSS score > or =2) was observed in 4 patients. Mean perfusion grade improved from a pretreatment score of 0 with increasing doses of r-tPA to 1.1 +/- 1.0 with 10 mg, 1.5 +/- 1.4 with 20 mg, 2.0 +/- 0.8 with 30 mg, and 2.7 +/- 1.0 with 40 mg. Mean thrombus degree decreased from a pretreatment score of 4 with increasing doses of r-tPA to 2.8 +/- 1.2 after 10 mg, 2.6 +/- 1.4 after 20 mg, 1.9 +/- 1.5 after 30 mg, and 1.4 +/- 1.5 after 40 mg. Asymptomatic intraparenchymal hemorrhage was observed on CT scan in 2 patients at 24 hours. CONCLUSION: Our study suggests that intraarterial r-tPA in doses up to 40 mg is relatively safe. The dose appears to facilitate the recanalization process by lysis of local thrombus and improvement in distal flow.

Adolescent↗