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Biomedical subjects

V V Halbach

Publications and source records attributed to V V Halbach.

At least 127 records · Page 7Linked to original sources
PubMed1988

MR evaluation of large intracranial aneurysms using cine low flip angle gradient-refocused imaging.

MR imaging has proved to be useful in evaluating large intracranial aneurysms. The parent artery and patent lumen can be identified as flow voids and differentiated from thrombus. However, in the presence of slow flow, even-echo rephasing, and motion artifact, increased intraluminal signal may be present, which may be difficult to distinguish from thrombus. Aneurysms are also dynamic lesions and exert pulsatile mass effect on adjacent structures. Further definition of vascular anatomy and physiology may aid in therapeutic planning and assessment. Cine MR is a new technique using a movie loop of sequential GRASS (gradient-recalled acquisition in the steady state) images obtained during various points in the cardiac cycle. The combination of GRASS images and cardiac gating thus allows cinegraphic display of vascular structures. A comparison of this method with routine T1- and T2-weighted MR imaging and angiography was made in a group of 13 patients with intracranial aneurysms greater than 1.5 cm in diameter. Eight of these patients underwent transvascular detachable balloon occlusion. With cine MR, flowing blood has high intensity due to flow-related enhancement. Turbulent and high-velocity flow can be recognized on the basis of signal loss, which occurs during systole. Thrombus demonstrated variable signal intensity, which remained unchanged during the cardiac cycle. Compared with routine MR sequences, there was less image degradation from phase-encoding artifacts and improved visualization of the neck of the aneurysm. Pulsatile mass effect was uniquely assessed. After transvascular embolization, cine MR demonstrated improved conspicuity of acute thrombus and higher contrast between flowing blood and the occlusion balloon when compared with routine MR. Confirmation of flow within the parent vessel, residual aneurysm lumen, and distal arterial branches is possible. If the parent vessel was occluded, cine MR yielded greater information than angiography. Cine MR provides additional anatomic and physiologic data in the evaluation and assessment of therapy of intracranial aneurysms. Information can be obtained that is not available with either routine MR or angiography. The inherent limitations of this new technique include partial-volume artifacts, less than optimal flow-related enhancement or spatial resolution, and poor data acquisition due to cardiac arrhythmias.

Adolescent↗
PubMed1987

Dural fistulas involving the cavernous sinus: results of treatment in 30 patients.

Thirty symptomatic indirect carotid cavernous fistulas were treated between 1978 and 1986 with a variety of treatment modalities. Combined carotid artery and jugular vein compression resulted in a complete cure in seven of 23 patients (30%) and improvement in one additional patient. There were no complications from this treatment, which is performed by the patient on an outpatient basis. Patients in whom carotid jugular compression therapy failed or who demonstrated cortical venous drainage or visual decline were treated with intravascular embolization. Embolization resulted in complete cure in 17 of 22 (77%) and improvement in four of 22 (18%). One patient required surgical excision of the involved dura after embolization to achieve complete cure. There was one permanent complication (stroke), which resulted in mild weakness caused by clot formation on a catheter.

Adult↗
PubMed1987

Dural fistulas involving the transverse and sigmoid sinuses: results of treatment in 28 patients.

Twenty-eight symptomatic dural fistulas involving the transverse and sigmoid sinuses were treated between 1978 and 1986 with a variety of treatment modalities. Occipital artery compression therapy resulted in a complete cure in two of nine patients (22%) and improvement in three of nine (33%). There were no complications from this treatment. Patients who were excluded or in whom compression therapy failed were treated with embolization alone or in conjunction with surgery. Of the 17 patients who underwent embolization alone, ten were cured and six were improved. Six patients had a combination of embolization and surgery; four patients were cured and two improved. There were three complications in this series, one related to surgery and two related to embolization.

Adult↗
PubMed1987

Carotid cavernous fistulae: indications for urgent treatment.

Angiographic and clinical data from 155 patients with carotid cavernous fistulae were retrospectively reviewed to determine angiographic features associated with increased risk of morbidity and mortality. These features included presence of a pseudoaneurysm, large varix of the cavernous sinus, venous drainage to cortical veins, and thrombosis of venous outflow pathways distant from the fistula. Clinical signs and symptoms that characterized a hazardous carotid cavernous fistula included increased intracranial pressure, rapidly progressive proptosis, diminished visual acuity, hemorrhage, and transient ischemic attacks. Cortical venous drainage from the carotid cavernous fistula is secondary to occlusion or absence of the normal venous outflow pathways and is associated with signs and symptoms of increased intracranial pressure and an increased risk of intraparenchymal hemorrhage. Angiographic demonstration of a cavernous sinus varix, with extension of the sinus into the subarachnoid space, is associated with an increased risk of fatal subarachnoid hemorrhage. Identification of these high-risk features provides a basis for making decisions about treatment.

Arteriovenous Fistula↗
PubMed1987

Intravascular balloon embolization of a large mid-basilar artery aneurysm. Case report.

A patient who presented with multiple episodes of subarachnoid hemorrhage was diagnosed as having a large mid-basilar artery aneurysm that had no definable surgical neck. Balloon embolization was performed utilizing two detachable silicone balloons to occlude the mid-basilar artery and the aneurysm. The procedure was carried out with the patient fully awake and alert. One day after the procedure, the patient developed pontine and cerebellar ischemia which completely resolved after 5 days on heparin therapy. A follow-up angiogram performed immediately after the procedure and at 3 months demonstrated complete occlusion of the mid-basilar artery and the aneurysm. The patient was intact neurologically upon discharge 5 days after the embolization procedure and has since resumed his normal activities. Balloon embolization therapy may offer some advantages over surgical methods for the treatment of such therapeutically challenging aneurysms.

Adult↗
PubMed1987

Variants of radiculomeningeal vascular malformations of the spine.

In recent years, it has become evident that the most common form of arteriovenous malformation to involve the spinal cord in adults is a low-flow fistula with its nidus located on the dura in relation to the dorsal nerve root. This lesion, termed "radiculomeningeal fistula" (RMF), is drained by the intradural coronal venous system and most likely causes neurological deficits due to raised venous pressure within the spinal cord. The therapy that was formerly recommended was multilevel laminectomy with microsurgical stripping of the intradural vessels. However, that procedure focused on the draining veins rather than the nidus, and it has been replaced by direct treatment of the nidus or by disconnecting the nidus from the coronal venous system. This paper reports variants of RMF's that show a wider spectrum of the clinical and radiological findings than has been previously reported. Three patients presenting with extradural venous drainage, intraspinal hemorrhage, and/or sudden non-hemorrhagic neurological decline are reported. A more complete understanding of RMF facilitates the radiological and clinical evaluation of these patients and enables the surgeon to modify the therapy in a significant way.

Adult↗
PubMed1986

MR imaging of the lumbar spine: anatomic correlations and the effects of technical variations.

A correlative anatomic study, a retrospective review of MR images performed in 35 patients, and a series of tests of the effectiveness of various MR scanning techniques were performed in order to improve comprehension of lumbar spine anatomy depicted on MR images, and thereby facilitate development of an optimal scanning protocol. Correlation of MR images with cryomicrotomed cadaver specimens enhanced understanding of the MR depiction of the intervertebral disks, ligamentum flavum, nerve roots, epidural fat, and epidural veins. Experiments were performed to assess the efficacy of a surface coil applied to the back, a solenoidal surface coil, a standard body coil, and an abdominal compression device in optimizing image quality. Experiments were also performed to determine the effect of alterations in the pulse sequence and variations of the phase-encoding axis. Based on these results, a protocol is proposed for routine imaging of the lumbar spine that yields high-resolution sagittal and oblique images and that does not require a surface coil. The recommended protocol employs heavily T1-weighted images with phase encoding along the z axis for sagittal images and along the x axis for axial images. This protocol yields multiple sagittal and oblique axial images through each of the lumbar disks, a larger field of view than obtained with surface coils, and a reduction of total imaging time to as little as 10 min.

Cadaver↗
PubMed1986

Balloon embolization of a large distal basilar artery aneurysm. Case report.

Interventional neurovascular techniques have advanced to a level where treatment of intracranial aneurysms by intravascular detachable balloon embolization therapy is now possible. A patient is presented who had a spontaneous subarachnoid hemorrhage from a large aneurysm of the distal basilar artery. The aneurysm arose at the bifurcation of the posterior cerebral arteries and measured 15 X 9 X 9 mm. With the patient fully awake, a detachable silicone balloon was passed into the basilar artery by a transfemoral arterial approach. Stenosis (greater than 60%) of the mid-section of the basilar artery, secondary to arterial vasospasm from the recent hemorrhage, was present. The stenosis was treated by transluminal angioplasty, after which the balloon was passed into the aneurysm and detached. A follow-up angiogram 3 months later demonstrated complete occlusion of the aneurysm and a widely patent basilar artery at the angioplasty site.

Adult↗
PubMed1986

Treatment of direct carotid cavernous sinus fistulae. Various therapeutic approaches and results in 148 cases.

From 1974 to 1986, 148 patients with carotid cavernous fistula (CCF) were evaluated for intravascular therapy. Four patients died from hemorrhage before treatment could be instituted and the CCF closed spontaneously in 5. Therapeutic approaches which resulted in complete occlusion in the remaining 139 cases were transarterial in 118, transvenous in 15 and external compression of the carotid artery and jugular vein in 6. The current treatment of choice of the direct CCF is intravascular embolization using detachable balloons, particulate emboli or liquid adhesive agents to occlude the CCF while attempting to preserve the carotid artery. In 15 patients it was technically too difficult to use the transarterial approach. The patients were therefore treated from a transvenous approach including access via the femoral vein, superior ophthalmic vein, intraoperatively from the inferior petrosal sinus or direct puncture of the cavernous sinus. Embolic agents used included detachable silicone balloons, steel minicoils, particulate emboli and isobutyl-2-cyanoacrylate. In 14 of these 15 patients total obliteration was achieved with marked improvement in symptoms. Complications occurred in 3 patients including perforation of the cavernous sinus resulting in subarachnoid hemorrhage, delayed pontine hemorrhage from subtotal occlusion of the fistula and transient increased proptosis.

Arteriovenous Fistula↗
PubMed1986

Closure of carotid cavernous sinus fistulae by external compression of the carotid artery and jugular vein.

From 1974-1986, 152 patients with carotid cavernous sinus fistulae (CCF) have been evaluated. Progressive closure of both dural and direct types of CCF have been noted utilizing intermittent external manual compression of the cervical carotid artery and jugular vein. In a group of 71 patients in whom this treatment was attempted, we have observed that 7 of 23 patients (30%) with dural CCF, and 8 of 48 patients (17%) with direct CCF had complete closure of their fistulae with no recurrence either clinically or at angiography done one year later. Closure occurred at varying times, from several minutes to 6 months (mean 41 days) following compression therapy. In those patients with CCF without rapidly progressive visual deterioration, cerebral ischemia, or other complicating factors, we recommend this technique with serial clinical follow-up and angiography before more definitive therapy is employed.

Adolescent↗
PubMed1986

Cervical carotid artery aneurysms and pseudoaneurysms. Treatment by balloon embolization therapy.

The treatment of high cervical carotid artery aneurysms and pseudoaneurysms is often difficult due to relative surgical inaccessibility. We are currently managing such lesions by detachable balloon embolization therapy. In 7 patients with acute cervical carotid pseudoaneurysms, the carotid artery was occluded by a trapping procedure above and below the lesion using detachable silicone balloons. In 3 patients with aneurysms that had well organized walls, a detachable balloon was placed directly within the aneurysm, inflated to exclude it from the circulation, and then detached. The carotid artery was therefore preserved.

Adult↗
PubMed1986

Intravascular detachable balloon embolization of intracranial aneurysms. Indications and techniques.

The treatment of intracranial aneurysms from a transvascular approach, with preservation of the parent vessel is now being performed in selected cases. From a transfemoral approach, a silicone detachable balloon is flow-directed up the carotid or vertebral-basilar artery, guided directly into the aneurysm and detached. The aneurysm is thus excluded from the circulation and the parent artery is preserved. Thus far, this technique has been successful in treating aneurysms in the cavernous carotid, carotid ophthalmic, posterior communicating, distal basilar, and posterior cerebral artery distributions. The indications and techniques of detachable balloon embolization therapy are presented.

Embolization, Therapeutic↗
PubMed1986

Percutaneous transluminal angioplasty of the subclavian and vertebral arteries.

Percutaneous transluminal angioplasty (PTA) for atherosclerotic lesions of the subclavian, vertebral, and brachiocephalic vessels is being performed in selected cases. Clinically patients presented with symptoms of vertebral basilar insufficiency, multiple transient ischemic attacks, subclavian steal syndrome, and motor weakness of the upper extremity. Thus far, 22 procedures have been performed with good results. This included 16 subclavian, 4 vertebral, and 2 innominate arteries. Follow-up has ranged from 8 to 26 months (mean 17 months). No permanent neurologic complications have occurred with this technique, and all patients had significant clinical and radiographic improvement following this procedure.

Aged↗
PubMedDate not supplied

Subclavian arteritis and pseudoaneurysm formation secondary to stent infection.

Technically uncomplicated percutaneous angioplasty and stent placement of a left subclavian artery stenosis was performed in a 56-year-old man for treatment of subclavian steal syndrome and vertebrobasilar insufficiency. Six days later the patient was readmitted with Staphylococcus aureus bacteremia and stigmata of septic emboli isolated to the ipsilateral hand. Nine days later he had computed tomography (CT) evidence of a contrast-enhancing phlegmon surrounding the stent. Despite clinical improvement and resolution of bacteremia on intravenous antibiotic therapy, the phlegmon progressed, and at day 21 a pseudoaneurysm was angiographically confirmed. The patient underwent surgical removal of the stented arterial segment and successful autogenous arterial reconstruction. The possible contributory factors leading to stent infection were prolonged right femoral artery access and an infected left arm venous access. Although the role of prophylactic antibiotics remains to be defined, it may be important in cases where the vascular access sheath remains in place for a prolonged period of time.

Aneurysm, False↗
PubMedDate not supplied

Transarterial embolization of vertebral hemangioma.

PURPOSE: The authors retrospectively reviewed their 4-year clinical experience to determine the role of transarterial embolization in the treatment of symptomatic vertebral hemangioma. PATIENTS AND METHODS: Eight patients (age range, 12-56 years) underwent a total of 10 embolization procedures; one patient underwent three procedures. The lesions were located between T-5 and L-5, and all patients presented with pain and symptoms referable to the lower extremities. RESULTS: Embolization was technically successful in all patients, and no complications were encountered. Six of eight patients underwent surgery within 48 hours of embolization; four of the six showed significant clinical improvement immediately after surgery and on follow-up (average, 34 months). Two patients did not improve postoperatively. Two patients initially underwent embolization as the sole therapy. The first refused surgery and did not improve clinically; the second underwent two embolization procedures without clinical improvement and eventually underwent a third followed by surgery, which resulted in clinical improvement. All patients were hemodynamically stable during surgery, and blood loss was not problematic in any patient. CONCLUSIONS: Overall, surgery was an effective treatment for symptomatic vertebral hemangioma and the authors conclude that transarterial embolization of vertebral hemangioma is a safe and efficacious adjunctive procedure to such surgery. However, embolization was not as promising as a sole therapeutic modality in this small group of patients.

Adolescent↗