Elisabeth Berg-Dammer

Endovascular therapy of brain AVMs prior to radiosurgery.

The purposes of this study were to determine the safety and efficacy of embolization of brain AVMs prior to radiosurgery and to evaluate the total obliteration rate achieved. The brain AVMs of 64 patients were subselectively embolized mainly with NBCA, platinum microcoils and/or PVA. The aim of embolization was the reduction of the target volume and/or the elimination of vascular structures bearing an increased risk of hemorrhage. Presenting symptoms were intracranial hemorrhage in 33 patients, a seizure disorder in 21 patients, and headache in 6 patients. Four AVMs had been detected as an incidental finding. The initial AVM volume was in the range of 0.5 to 84 cc (mean 17 cc). Grading of the AVMs according to the Spetzler-Martin scale showed the following distribution: grade I, 3x; II, 13x; III, 11x; IV, 17x; V, 4x; VI, 16x. A total of 300 endovascular procedures including 47 subselective catheterizations without and 253 with embolization were performed. A size reduction of the AVMs between 10% and 95% (mean 63%, median 70%) was achieved. Neurological symptoms due to treatment complications were transient in 12 patients, of minor clinical significance but permanent in 4 patients. Following radiosurgery, one patient died due to recurrent intracerebral hemorrhage. Three patients are doing well but refused final follow-up angiography. A total of 30 patients is currently within the latency interval after radiosurgery. Radiosurgery failed to obliterate the embolized AVMs in 16 patients. Angiography confirmed complete nidus obliteration in 14 patients. The endovascular treatment of brain AVMs prior to radiosurgery proved safe and effective and may be considered in either high grade or incidental AVMs. AVM obliteration after embolization and radiosurgery is less frequently achieved than after stereotactic irradiation of primarily small AVMs.

Long-Term Outcome after Local Intra-Arterial Fibrinolysis of Basilar Artery Thrombosis

Thrombolytic therapy of acute basilar artery (BA) thrombosis has been shown to reduce mortality and avoid a fatal outcome. Objective of this study was to investigate the long-term clinical outcome following intra-arterial fibrinolysis of occlusions of the BA. We retrospectively analyzed the clinical records and neuroradiologic results of 20 consecutive patients who had intra-arterial fibrinolysis of acute occlusions of the BA between 1982 and 1990. All patients were followed neurologically for a period of up to 12 years, including assessment of the Barthel index (BI) and brain CT or MRI studies. At the time of treatment, 6 patients were somnolent and 14 comatose, and tetraparesis was present in 15. The time between the onset of symptoms and treatment ranged from 1 to 48 h. The mortality rate was 35% (7/20 patients). Functional outcome was excellent in 9, 78%, of 13 survivors (BI <85). During the cumulative follow-up period (125 patient years) there was 1 death from myocardial infarction and 1 death from pneumonia. Vascular events during follow-up were myocardial infarction (n = 3) and a single cerebral transient ischemic attack. Despite the fact that our series was biased towards patients with severe symptoms, 65% (13/20) survived, and 78% of the survivors reached independence in daily life. These results provide evidence that local fibrinolysis of BA occlusion reduces mortality, and the long-term prognosis of the survivors is better than previously thought. None of our patients had a further stroke during the follow-up period, which indicates that acute BA occlusion is not a strong indicator for advanced arteriosclerotic disease.

Sumatriptan: Vasoactive Effect on Human Dural Vessels, Demonstrated by Subselective Angiography

Sumatriptan, a selective 5-hydroaytryptamine (5HT1D)-receptor agonist, has recently been introduced in the pharmacotherapy of acute migraine attacks. The potential vasoactive effect of sumatriptan on human dural vessels in vivo, however, is still a matter of controversy. We investigated the effects of sumatriptan on dural vessels after subcutaneous or intra-arterial injection. During interventional angiography, the middle meningeal artery (MMA) of nine patients was catheterized with a microcatheter using the transfemoral route. Three MMA were entirely normal, two supplied a dural arteriovenous fistula (AVF) and four were transdural feeders to a brain arteriovenous malformation (AVM). Sumatriptan was injected either into the subcutaneous tissue of the right shoulder (6 mg, two patients) or into the catheterized MMA (2 mg, six patients). The substance caused a marked vasoconstriction of the three normal MMA, visible angiographically and confirmed by intravascular Doppler ultrasonography. Vasoconstriction was still present in the last angiogram obtained 15 min post-injection. Slightly hypertrophied feeders to dural AVF and to brain AVM showed some vasoconstriction in one and four patients, respectively. In two patients with markedly hypertrophied dural feeders to a dural AVF and to a brain AVM, respectively, rapid shunting probably prevented obvious vasoactive effects of sumatriptan. The data obtained by angiography and intravascular Doppler ultrasonography provide strong evidence that sumatriptan has a vasoconstrictive effect on normal as well as hypertrophied dural vessels.

Cure of a direct carotid cavernous fistula by endovascular stent deployment.

A 53-year-old woman underwent surgical thrombendarterectomy for treatment of artherosclerotic stenoses of her left internal carotid artery (ICA). A Fogarty catheter was used during this operation. The postoperative course was complicated by the development of a sixth cranial nerve palsy, protrusio, chemosis and ciliar injection of both eyes. Digital subtraction angiography showed a direct fistula between the cavernous segment of the left ICA and the cavernous sinus, with early and retrograde opacification of both superior ophthalmic veins. Endovascular occlusion of the fistula was achieved with preservation of the ICA by stent deployment over the rupture site of the ICA, as two detachable balloons could not obliterate the fistula while preserving the ICA patent. Follow-up angiography 7 months after the endovascular treatment confirmed persisting occlusion of the fistula with a patent ICA. Highly flexible porous coronary stents can easily be introduced into tortuous vessels, including the distal ICA. The haemodynamic effects achieved by stent deployment together with two balloons detached in the cavernous sinus may be sufficient to interrupt a direct carotid cavernous fistula.

Thromboembolic Occlusion of the Middle Cerebral Artery due to Angiography and Endovascular Procedures: Safety and Efficacy of Local Intra-Arterial Fibrinolysis

The purpose of this study was to evaluate the safety and efficacy of local intra-arterial fibrinolysis (LIF) in the treatment of thromboembolic MCA occlusions that occurred during angiography and/or endovascular procedures. A retrospective analysis included 14 consecutive cases of iatrogenic thromboembolic MCA occlusions, encountered between January, 1983 and December, 1994 in a single neuroradiological department. During that period, a total of approximately 12,000 cerebral angiographies and of 4,000 neuroendovascular procedures were performed. Only patients in whom vessel occlusion by an embolic agent (e.g., glue, particles) could be positively excluded were accepted. LIF was performed using standard microcatheters. The fibrinolytic agents were streptokinase or urokinase, in varying dosages. Immediate LIF resulted in a complete recanalization of the previously occluded vessel within 2 h or less in 8/14 patients, all of whom were asymptomatic at discharge. Partial recanalization was achieved in 5/14 patients. Four of these patients showed mild to moderate neurological deficits on discharge. In 1 patient, LIF was initiated 3 h after embolic occlusion of the MCA due to cerebral angiography. No recanalization was observed in this case. The patient improved from her initial status but continued to show moderate hemiparesis and aphasia. None of the patients sustained an intracranial hemorrhage due to LIF. Acute thromboembolic occlusion of the MCA is a rare consequence of angiography and endovascular therapy. LIF is a safe and effective tool in the treatment of this complication. Thus, LIF is an indispensable part of neuroendovascular procedures. The well-defined onset time and site of vessel occlusion, the angiographically charted effect of fibrinolytic therapy, and the possibility of following up these patients with angiography, MRI and clinical investigation are all factors which render this complication and its correction a unique clinical model for evaluating the benefits and limitations of LIF in the treatment of acute MCA occlusion.

Pseudoaneurysmen der extrakraniellen A. carotis interna

ZusammenfassungPseudoaneurysmen der extrakraniellen A. carotis interna können traumatisch verursacht sein oder sind die Folge einer spontanen Gefäßdissektion. Von ihnen geht die Gefahr thrombembolischer Verschlüsse nachgeschalteter Gefäße aus. Die Möglichkeit und Art der Behandlung ist abhängig von der Lokalisation und der Art der Verletzung, der Kollateralversorgung der abhängigen Hemisphäre, der klinischen Symptomatik, dem Nachweis einer Größenänderung des Aneurysmas sowie von dem Alter des Patienten. In erster Wahl werden die Patienten mit Antikoagulanzien und/oder Thrombozytenaggregationshemmern behandelt. Kommt es unter dieser Therapie zu einer Größenzunahme des Pseudoaneurysmas bzw. zu weiteren Thrombembolien oder bestehen Kontraindikationen gegen die medikamentöse Behandlung, sind invasive Behandlungsverfahren angezeigt. In Betracht kommen die Ligatur des aneurysmatragenden Gefäßes, ggf. nach Anlage eines extra-intrakraniellen Bypasses, die Aneurysmaresektion mit Gefäßrekonstruktion der A. carotis interna und die endovaskuläre Ausschaltung des Aneurysmas, ggf. einschließlich der A. carotis interna. Pseudoaneurysmen unmittelbar unterhalb der Schädelbasis sind chirurgisch nicht oder nur mit hohem Aufwand behandelbar. Zur Ausschaltung solcher Pseudoaneurysmen unter Erhalt der A. carotis interna bietet sich heute die Stentimplantation in das disseziierte Gefäß an. Wir berichten über zwei Patienten mit stumpfen Verletzungen der A. carotis interna mit basisnahen Pseudoaneurysmen. Die endovaskuläre Stentimplantation, ggf. kombiniert mit Coilokklusion, ist eine neue Behandlungstechnik, deren Wirksamkeit und Sicherheit im Vergleich mit den anderen invasiven Verfahren und der medikamentösen Behandlung allerdings noch zu überprüfen ist.SummaryPseudoaneurysms of the extracranial internal carotid artery (ICA) can be caused by external injury or may be due to spontaneous dissection. Pseudoaneurysms bear an increased risk of arterio-arterial embolism. Treatment of pseudoaneurysms is influenced by the location and the type of injury, associated injurys, collaterals to the ipsilateral hemisphere, neurological signs and symptoms, growth of the lesion and patient age. Potential treatment regimen include conservative and medical approaches with anticoagulation and antiplatelet therapy, extra-intracranial bypass, resection of the pseudoaneurysm with vessel reconstruction, ligation or endovascular balloon occlusion of the ICA. Pseudoaneurysms of the ICA adjacent to the scull base require a major surgical procedure. If there are contraindications for vessel occlusion conservative or medical treatment used to be the only therapeutic alternatives. We report the treatment of two patients with extracranial ICA pseudoaneurysms after blunt injury with stent placement (in one case combined with coil embolization) as a further treatment option.

Local thrombolytic therapy for thrombembolic occlusion of the middle cerebral artery

We report on 10 patients with thromboembolic occlusion of the middle cerebral artery (MCA) who underwent local thrombolytic therapy. Six patients developed a MCA occlusion during long-standing interventional neuroradiological procedures, while four had a proven or suspected cardio-embolic stroke. Streptokinase or urokinase was applied by a microcatheter placed into the thrombus within six hours of clinical onset. Complete or partial revascularization was achieved in all patients. Recovery was complete in seven and partial in three of the patients. In two patients, minor haemorrhagic transformation of the infarct occurred, which did not lead to neurological deterioration. It is concluded that in a selected group of patients with MCA occlusion, local thrombolytic therapy represents a safe and effective therapy.

Endovascular laser detachment of platinum alloy microcoils: Principle and initial experimental experience

The aim of the investigation was the technical realization and approval of a new method for insertion and detachment of platinum alloy microcoils and other vascular implants via standard microcatheters. Flexible lightconducting fibers, 105 microns in diameter were connected to platinum alloy microcoils. It was examined whether an insertion wire, a lightconducting fiber and a platinum alloy microcoil could be advanced through a Tracker-18 (Target) microcatheter. The detachment of the attached coil from the lightconducting fiber was investigated. Platinum alloy microcoils can be attached to available lightconducting fibers in a reliable and reproduceable manner. Together with the fiber they can be advanced via a Tracker-18 microcatheter. Only extremely tortuous vessels may increase the friction to critical values. A Ho-YAG laser source was used. This allowed the instantaneous detachment of microcoils from laser fibers. In contrast to electrolytical detachment, no foreign substances are released to the blood stream. The detachment does not require waiting time and does not activate thrombus formation. Due to specific technical features, injuries of the vessel wall are avoided. After further miniaturization and adaption of the lightconducting fibers to the required characteristics, laster detachment may have the potential to replace current methods such as electrolytical and mechanical coil detachment.