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Biomedical subjects

T A Tomsick

Publications and source records attributed to T A Tomsick.

At least 37 records · Page 2Linked to original sources

Obliteration of a giant carotid aneurysm after extracranial-to-intracranial bypass surgery: case report.

BACKGROUND: Proximal arterial occlusion, with or without extracranial-to-intracranial (EC-IC) bypass, is frequently used as treatment for giant intracranial aneurysms that are unclippable. The authors report on a patient who had obliteration of a giant unruptured aneurysm of the right internal carotid terminus after undergoing an EC-IC bypass without proximal arterial ligation. METHODS: This 71-year-old woman presented with repeated right cerebral ischemia caused by a giant saccular aneurysm of the right internal carotid terminus. Direct surgical clipping of the aneurysm was not recommended because of the patient's age and because of the morphology of the aneurysm. She could not tolerate occlusion of the right internal carotid artery (ICA) and, therefore, first underwent an EC-IC bypass. Four weeks later, she returned to undergo a balloon occlusion of the right ICA proximal to the aneurysm. RESULTS: The right distal ICA and aneurysm were found to be spontaneously thrombosed. At 2-year follow-up, the aneurysm was shown to be completely obliterated on the magnetic resonance imaging scans. CONCLUSIONS: The authors conclude that hemodynamic changes in the blood flow of the parent artery after EC-IC bypass caused this occurrence.

Aged↗

Spinal dural arteriovenous fistulas: recognizing the spectrum of magnetic resonance imaging findings.

Spinal dural arteriovenous fistulas are the most common type of vascular malformation to involve the spinal cord. In this report, we describe and analyze the various magnetic resonance imaging (MRI) findings of spinal dural arteriovenous fistulas in order to increase awareness and prompt timely diagnosis. We reviewed 14 patients evaluated and treated for spinal dural arteriovenous fistulas over a seven year period, with special attention to findings on MRI. All patients had regions of increased cord signal on T2-weighted MRI, with corresponding hypointense signal on T1-weighted images in 11 patients (79 percent). Thirteen (93 percent) of 14 patients had focal increased cord caliber and eight (57 percent) had prominent intradural vessels. Cord enhancement was observed in all seven patients who were administered contrast and two patients had enhancement of intradural vessels. These imaging findings are relatively nonspecific, but should lead to further investigation with myelography or arteriography in the appropriate clinical setting.

Adult↗

Cervical myelopathy associated with intracranial dural arteriovenous fistula: MR findings before and after treatment.

The MR findings in three patients with intracranial dural arteriovenous fistula associated with cervical myelopathy are described. The MR appearance of an enlarged cord with associated abnormal signal and enhancement is nonspecific and can simulate tumor, demyelination, and inflammation. Enlarged perimedullary vessels may not always be identifiable, but if present, should suggest the presence of an arteriovenous fistula.

Aged↗

Long-term results in direct carotid-cavernous fistulas after treatment with detachable balloons.

Transarterial embolization of direct carotid-cavernous fistulas (CCFs) using detachable balloons is the best initial option for occlusion of the fistula and preservation of the internal carotid artery. However, the long-term safety and efficacy of this treatment is unknown. The authors reviewed the long-term outcome of 87 patients with 88 direct CCFs occluded by detachable balloons. Clinical follow up was obtained in 48 (83%) of 58 patients treated with latex balloons (mean follow-up period 10 years, range 5.9-15.5 years) and 28 (97%) of 29 patients treated with silicone balloons (mean follow-up period 4 years, range 1-6.6 years). Two patients were treated with both balloon types. There were no late recurrent symptoms of cranial bruit, proptosis, chemosis, or arterialized conjunctiva in patients treated with either latex or silicone balloons. Diplopia improved in all patients; however, five patients required shortening of the lateral rectus muscle. Delayed ischemia occurred in three patients: one patient had a transient ischemic episode 5 years after treatment with latex balloons and two patients (85 and 90 years old) who had ruptured spontaneous intracavernous aneurysms suffered cerebral infarctions 6 weeks and 4 months, respectively, after treatment with silicone balloons. There were five deaths in the series unrelated to balloon treatment. These results show that after transarterial embolization of direct CCFs using either silicone or latex detachable balloons, the long-term risks are low for fistula recurrence, symptomatic foreign body reaction, symptomatic pseudoaneurysm formation, and cerebral ischemia.

Adolescent↗

Angiography in the evaluation of head and neck trauma.

Cerebrovascular trauma is a heterogeneous group of injuries including arterial dissections, traumatic aneurysms, arteriovenous fistulas, and venous occlusions. Detection of vascular trauma may be difficult because of variations in clinical presentation; however, in recent years, increased awareness and understanding of these injuries has improved the ability to detect and subsequently treat many lesions. Despite advances in other imaging modalities, angiography remains the primary radiographic tool used in the evaluation of traumatic vascular lesions.

Aortic Dissection↗

Normal appearance of arachnoid granulations on contrast-enhanced CT and MR of the brain: differentiation from dural sinus disease.

PURPOSE: To determine the imaging appearance and frequency with which arachnoid granulations are seen on contrast-enhanced CT and MR studies of the brain. METHODS: We retrospectively reviewed 573 contrast-enhanced CT scans and 100 contrast-enhanced MR studies of the brain for the presence of discrete filling defects within the venous sinuses. An anatomic study of the dural sinuses of 29 cadavers was performed, and the location, appearance, and histologic findings of focal protrusions into the dural sinus lumen (arachnoid granulations) were assessed and compared with the imaging findings. RESULTS: Discrete filling defects within the dural sinuses were found on 138 (24%) of the contrast-enhanced CT examinations. A total of 168 defects were found, the majority (92%) within the transverse sinuses. One third were isodense and two thirds were hypodense relative to brain parenchyma. Patients with filling defects were older than patients without filling defects (mean age, 46 years versus 40 years). Discrete intrasinus signal foci were noted on 13 (13%) of the contrast-enhanced MR studies. The foci followed the same distribution as the filling defects seen on CT scans and were isointense to hypointense on T1-weighted images, variable in signal on balanced images, and hyperintense on T2-weighted images. Transverse sinus arachnoid granulations were noted adjacent to venous entrance sites in 62% and 85% of the CT and MR examinations, respectively. Arachnoid granulations were found in 19 (66%) of the cadaveric specimens, in a similar distribution as that seen on the imaging studies. CONCLUSION: Discrete filling defects, consistent with arachnoid granulations, may be seen in the dural sinuses on 24% of contrast-enhanced CT scans and on 13% of MR studies. They are focal, well-defined, and typically located within the lateral transverse sinuses adjacent to venous entrance sites. They should not be mistaken for sinus thrombosis or intrasinus tumor, but recognized as normal structures.

Adult↗

Management of 100 consecutive direct carotid-cavernous fistulas: results of treatment with detachable balloons.

Direct carotid-cavernous fistulas are high-flow shunts with a direct connection between the internal carotid artery and the cavernous sinus. The goals of treatment are to eliminate the fistula and preserve carotid artery patency. The authors reviewed the outcome of 98 patients with 100 consecutive direct carotid-cavernous fistulas initially treated by transarterial embolization with detachable balloons (1979-1992) at the University of Cincinnati Medical Center to evaluate the merits of this technique and to provide a standard for comparison with future treatment alternatives. Among 100 fistulas, 76 were traumatic in origin, 22 resulted from a ruptured aneurysm, and 2 were iatrogenic. The most common presentations were orbital bruit (80%), proptosis (72%), chemosis (55%), abducens palsy (49%), and conjunctival injection (44%). Eighty-eight fistulas were successfully occluded in 86 patients with detachable balloon(s), and internal carotid blood flow was preserved in 66 patients (75%). Initial attempts at balloon occlusion failed in four patients in whom the fistula eventually closed spontaneously. Five patients required direct surgery to occlude the fistula, and two were treated with nondetachable balloons; one patient died from injuries sustained from trauma. The permanent neurological complication rate was 4%, including cerebral infarction in one patient, frontal intracerebral hemorrhage in one patient, and vision loss in another patient. One death occurred related to cerebral infarction from a balloon that shifted. Transient ischemia occurred in three patients. On the basis of these results, we conclude that transarterial embolization with detachable balloons provides a high rate of fistula obliteration with low morbidity and is the best initial procedure to treat direct carotid-cavernous fistulas.

Adolescent↗

Endovascular therapy of intractable epistaxis complicated by carotid artery occlusive disease.

Three cases of intractable spontaneous posterior epistaxis refractory to nasal packing and complicated by ipsilateral carotid artery occlusive disease were successfully treated with internal maxillary artery occlusion with microcoils. There were no complications and no recurrent episodes of epistaxis at a mean follow-up of 12 months. The presence of ipsilateral carotid artery disease requires modification of standard distal internal maxillary artery embolization because of the recruitment of external carotid to internal carotid and external carotid to ophthalmic artery collateral pathways, with subsequent risk of particle embolization of these arterial distributions. Proximal internal maxillary artery microcoil embolization eliminates this risk and is equivalent to surgical internal maxillary artery ligation. This procedure also provides additional information about the internal carotid artery collateral circulation.

Aged↗

Adult choroidal vein of Galen malformation.

We report staged embolization and stereotactic radiation in a true adult choroidal vein of Galen malformation. Management dilemmas and their resolutions are also discussed.

Adult↗

Treatment of aneurysms of the internal carotid artery by intravascular balloon occlusion: long-term follow-up of 58 patients.

Long-term evaluation of patients with aneurysms of the internal carotid artery (ICA) treated by intravascular balloon occlusion has not been reported. From 1977 to 1992, 58 patients (age 14 to 81 years) with ICA aneurysms were treated at our institution by this technique. The aneurysms included 40 intracavernous carotid, 5 petrous carotid, 3 cervical carotid, and 10 ophthalmic segment aneurysms. Presenting symptoms were caused by mass effect in 45 patients, transient ischemia or cerebral infarction as a result of emboli in 6, subarachnoid hemorrhage in 4, and epistaxis in 3. Preoperative temporary balloon occlusion of the ICA combined with cerebral blood flow monitoring and induced hypotension were used to determine tolerance for occlusion. Two patients not tolerating test occlusion required an extracranial-intracranial bypass procedure, and another patient underwent extracranial-intracranial bypass prior to test occlusion because of contralateral ICA stenosis. In 55 patients, aneurysms were excluded from the circulation by either occluding the proximal ICA or trapping the aneurysm neck. In three patients, the aneurysm was directly obliterated with intravascular balloons with preservation of the parent ICA. Three patients died during treatment, one from subarachnoid hemorrhage and two from cerebral infarction. Mean follow-up was 76 months (range, 6 months to 15 years). Six patients who developed transient ischemia caused by emboli responded to volume expansion and anticoagulation treatment. Two patients developed a delayed infarction, and one patient developed aneurysm enlargement that required surgical clipping and obliteration. (ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Aneurysm formation after carotid occlusion.

We present two cases of subarachnoid hemorrhage caused by aneurysm development and enlargement in the anterior communicating artery complex. The cases occurred in a series of 58 balloon occlusions for unclippable giant aneurysms of the internal carotid artery.

Aneurysm↗

Feeding artery pedicle aneurysms: association with parenchymal hemorrhage and arteriovenous malformation in the brain.

The association between arteriovenous malformations (AVM's) and aneurysms is well documented in the literature. However, a specific type of aneurysm, termed a "pedicle" aneurysm, has received little attention despite its role as a primary source of hemorrhage. The authors report four recent cases of patients with cerebral AVM's who bled from aneurysms arising from the midportion of AVM-feeding artery pedicles. Angiography, computerized tomography, and magnetic resonance imaging confirmed the origin of the hemorrhage from the pedicle aneurysm in each case. Because pedicle aneurysms are at risk for recurrent rupture, they represent an important subclassification of aneurysms associated with AVM's. The authors have expanded the previous classification systems for aneurysms associated with AVM's to include pedicle aneurysms; this classification is based on the location of the aneurysm and its relationship to the malformation. Complete documentation of such aneurysms as the potential source of hemorrhage is recommended, and prompt intervention by embolization and/or surgical resection is indicated for this dangerous aneurysm associated with cerebral AVM's.

Adult↗

Management of tentorial dural arteriovenous malformations: transarterial embolization combined with stereotactic radiation or surgery.

The clinical, anatomical, and radiological features of nine cases of tentorial dural arteriovenous malformations (AVM's) are presented, and 45 reported cases are reviewed. Unlike dural AVM's of the transverse sigmoid and cavernous sinuses that usually have a benign natural history, dural AVM's of the tentorium typically present with hemorrhage or progressive neurological deficit. In this series, patients ranged in age from 52 to 72 years and included five men and four women. These patients presented with subarachnoid hemorrhage, parenchymal hemorrhage, brainstem dysfunction, cerebellar signs, and obstructive hydrocephalus. Malformations were fed principally by the meningohypophyseal trunk, branches of the middle meningeal artery, and the occipital artery. Venous drainage was uniform through the cortical veins (predominantly the mesencephalic, petrosal, and cerebellar veins). Eight of the nine patients had an associated venous aneurysm(s); two had more than one venous aneurysm, and two patients had a vein of Galen aneurysm associated with the tentorial dural AVM. Eight of nine patients improved after treatment, including four patients with complete obliteration of the dural AVM. Based on our experience, we have developed a treatment protocol for tentorial dural AVM's that uses transarterial embolization followed by direct microsurgery or stereotactic radiation. These therapies, applied in a staged manner, have proven safe and relatively effective for the treatment of dural AVM's.

Aged↗

Hyperdense middle cerebral artery sign on CT: efficacy in detecting middle cerebral artery thrombosis.

The hyperdense middle cerebral artery sign is a CT predictor of the development of a large cerebral infarct. The limits of detectability were tested in a blinded, then unblinded analysis of CT scans from 25 acute stroke patients. In the initial blinded analysis, sign detection exhibited the following mean values: sensitivity, 78.5%; specificity, 93.4%; positive predictive value, 66%; negative predictive value, 96.4%; accuracy, 91.3%. Kappa statistics analysis indicated poor interobserver agreement (k = .38). Results of unblinded analysis were as follows: sensitivity, 69%; specificity, 94.4%; positive predictive value, 82.8%; negative predictive value, 88.7%; accuracy, 87.3%. There was fair unblinded interobserver agreement (k = .53). Unblinded analysis had a lower false-positive frequency and did not increase the number of true-positive determinations. We conclude that detection of the hyperdense middle cerebral artery sign on CT scans by multiple observers is a sensitive, accurate, and predictive indicator of middle cerebral artery thromboembolism.

Acute Disease↗

Hyperdense middle cerebral artery: incidence and quantitative significance.

The hyperdense middle cerebral artery sign (HMCAS) is recognized as a CT finding that indicates thrombus or embolus within the middle cerebral artery. The incidence and significance of this sign are quantitatively evaluated in 50 patients entered into experimental drug studies for treatment of cerebral infarction.

Acute Disease↗