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Biomedical subjects

R F Spetzler

Publications and source records attributed to R F Spetzler.

At least 73 records · Page 4Linked to original sources
PubMed1997

Concurrent aneurysm rupture and thrombosis of high grade internal carotid artery stenosis: report of two cases.

BACKGROUND: The simultaneous presentation of aneurysmal subarachnoid hemorrhage and thrombosis of a high-grade internal carotid artery stenosis is rare, and their management raises several treatment dilemmas. METHODS: Two such patients with ruptured aneurysms are presented: one with high-grade internal carotid artery stenosis that progressed to occlusion and one with acute internal carotid artery occlusion. RESULTS: Both patients were treated with craniotomy for clipping of the ruptured aneurysm followed by carotid thromboendarterectomy. CONCLUSIONS: We advocate urgent surgical treatment of both lesions, dealing with the most symptomatic lesion first. These two cases demonstrate the importance of reestablishing blood flow in patients with an acutely thrombosed carotid artery.

Aged↗
PubMed1997

Aneurysm of the intradural artery of Adamkiewicz treated with muslin wrapping: technical case report.

OBJECTIVE AND IMPORTANCE: An exceedingly rare, isolated spinal arterial aneurysm and its management are presented. CLINICAL PRESENTATION: A 30-year-old man who presented with severe lower back pain and headache underwent a computed tomographic study of his head that disclosed nothing abnormal and a lumbar puncture that revealed bloody, xanthochromic cerebrospinal fluid. The findings from cerebral angiography were normal, and the results from spinal angiography were consistent with a diagnosis of an aneurysm of the artery of Adamkiewicz. INTERVENTION: A transthoracic approach with a partial T11 vertebrectomy gained exposure to this anteriorly located lesion. A fusiform aneurysm of the intradural portion of the artery of Adamkiewicz was discovered. Excision of the aneurysm with a vascular bypass was deemed impossible. The lesion was treated with muslin wrapping. One year after surgery, the patient remains at his baseline neurological condition. CONCLUSION: A review of the literature revealed only one other reported case of a ruptured aneurysm of the artery of Adamkiewicz, which was discovered postmortem. Therefore, this case represents the first report of a diagnosed and treated artery of Adamkiewicz aneurysm.

Adult↗
PubMed1997

Treatment for intracranial dural arteriovenous malformations: a meta-analysis from the English language literature.

OBJECTIVE: The treatment of intracranial dural arteriovenous malformations (DAVMs) remains problematic. Options include ligature of feeding vessels, endovascular procedures, surgical obliteration, or a combination of the latter two. We conducted a meta-analysis of the English language literature on DAVMs to determine the most effective treatment option related to location and angiographic characteristics. METHODS: The criteria for inclusion were pre- and post-treatment angiography, a description of the type of treatment, and clinical outcome. The analysis included a total of 258 patients, 248 from a review of 223 published articles and 10 from the authors' series. DAVMs were divided into six categories by location, and the results of treatment were compared based on obliteration rates using chi 2 analysis. RESULTS: In transverse-sigmoid sinus DAVMs (n = 64), combined therapy (endovascular plus surgical treatment) proved significantly more effective than either therapy alone (P < 0.01). For lesions of the tentorial incisura (n = 66), combined therapy and surgical obliteration alone proved superior to embolization (P < 0.001). For lesions of the cavernous sinus (n = 67), treatment was primarily endovascular, with success rates of 62 to 78% for transarterial and transvenous approaches, respectively. In the anterior fossa (n = 23), surgical obliteration was highly effective, with a success rate of 95%. The small number of cases in both the superior sagittal sinus (n = 28) and middle fossa (n = 10) regions, precluded any statistical analysis. Finally, simple ligature of feeding vessels produced success rates of only 0 to 8% and can no longer be recommended. CONCLUSION: There is no single ideal treatment for the obliteration of DAVMs. The management of each case is best considered individually. The results of this review serve as a rational starting point for the selection of treatment options.

Adolescent↗
PubMed1997

Technical aspects and recent trends in the management of large and giant midbasilar artery aneurysms.

OBJECTIVE: Cranial base approaches that involve radical petrosectomy are associated with significant rates of morbidity. We have sought alternative approaches to the midbasilar artery to reduce the extent of temporal bone removal and correspondingly to reduce complications while still providing adequate surgical exposure. The extended orbitozygomatic and far-lateral approaches are two such approaches. We compared our experience with these approaches to our experience with the standard transpetrosal approaches in the treatment of midbasilar artery aneurysms. METHODS: Between 1990 and 1995, 28 patients with large and giant midbasilar artery aneurysms were treated with approaches involving either radical or conservative petrosectomy. RESULTS: Overall, good outcomes (Glasgow Outcome Scale scores of 1 and 2) were observed in 21 patients (75%), and three patients (11%) had permanent treatment-associated neurological deficits. Four patients died. Later in the series, the pterional-subtemporal approach (four patients) was supplanted by the orbitozygomatic approach (six patients). The increased use of hypothermic circulatory arrest involved exposure of the midbasilar region from above (orbitozygomatic approach) and below (far-lateral approach, 13 patients). Concomitantly, the use of transpetrosal approaches (five patients) decreased. CONCLUSION: Modified orbitozygomatic and far-lateral approaches adequately expose the midbasilar region and can replace transpetrosal approaches in some cases. These extended approaches can be associated with lower morbidity rates than can transpetrosal approaches. Hypothermic circulatory arrest is critical to clipping large and giant midbasilar artery aneurysms directly when approaches that conserve the temporal bone are used.

Adolescent↗
PubMed1997

Neurosurgery at the Barrow Neurological Institute.

Neurosurgery at the Barrow Neurological Institute exists within the unique context of this nonuniversity-based center. The institute, a relative newcomer to academic medicine, opened in Phoenix in 1961 under the leadership of John Raymond Green, M.D., who remained its medical director until his retirement at the end of 1985. Since then, the institute has experienced a dynamic growth phase in its clinical and academic arenas. This article describes how the development of the institute has shaped the program in neurosurgery and vice versa.

Arizona↗
PubMed1997

Surgical resection of intramedullary spinal cord cavernous malformations: delayed complications, long-term outcomes, and association with cryptic venous malformations.

OBJECTIVE: To examine outcomes and delayed complications after the surgical resection of intramedullary spinal cord (IMSC) cavernous malformations. The association of these lesions with cryptic intraparenchymal venous malformations at surgery also was analyzed. METHODS: The records of 17 patients who underwent resection of their histologically verified IMSC cavernous malformations were analyzed. There were nine female and eight male patients (mean age, 40.1 yr). The locations of the cavernous malformations were as follows: cervical, eight; thoracic, eight; and conus medullaris, one. The mean follow-up period was 48.3 months. Immediate postoperative and long-term neurological outcomes were compared, and delayed complications were assessed. RESULTS: The patients presented with radiculopathy (n = 6), myelopathy (n = 10), and conus medullaris syndrome (n = 1). Intraoperatively, 16 (94.1%) IMSC cavernous malformations were associated with cryptic venous malformations. Immediately after surgery, four (23.5%) patients worsened neurologically whereas one (5.9%) improved. At long-term follow-up, however, 10 (58.9%) patients had improved and only 1 (5.9%) remained worse. Four (23.5%) patients experienced delayed complications. Three had undergone incomplete resection and experienced subsequent hemorrhage, necessitating subsequent resection. Another patient developed radiological tethering of the thoracic spinal cord without clinical symptoms. Two of the three patients who had undergone subsequent resection developed symptomatic tethering of the cervical spinal cord. In one of the two patients, the tethering was associated with an iatrogenic cerebellar tonsillar herniation. Both patients required surgical intervention. CONCLUSIONS: The frequent coexistence of IMSC cavernous malformations with cryptic venous malformations in this series indicates a need for operative vigilance to preserve these venous anomalies. Delayed complications were the result of incomplete resection. The resultant hemorrhage required reexploration, which led to tethering of the spinal cord. Most patients who underwent resection, however, had improved neurologically at long-term follow-up.

Adolescent↗
PubMed1997

Angiographic follow-up in 37 patients after radiosurgery for cerebral arteriovenous malformations as part of a multimodality treatment approach.

Modified Linac radiosurgery was utilized at our institution between 1990 and 1995 in 54 patients with cerebral arteriovenous malformations (AVMs) as part of a multimodality therapeutic approach. Most patients also underwent surgery and embolization of the AVMs prior to radiosurgery. The goal of the adjunctive radiosurgical treatment was the complete angiographic obliteration of the deep residual AVM after subtotal embolization and resection. Radiosurgery was used as the primary treatment of some small deep AVMs which were judged to have a high risk of morbidity if approached surgically. Of the 54 patients, 37 have had follow-up angiograms available for review. The median time interval between radiosurgery and the most recent angiogram was 22 months (range 5-66 months). This is a retrospective report on the angiographic follow-up available on this selected group of patients with difficult AVMs. All angiograms were evaluated for the presence of residual AVM. If any residual AVM was present, a decrease in size of more than 50% was noted as significant. The hospital and office charts of all patients were reviewed and the patients and families were contacted for up-to-date clinical follow-up. Prior to treatment, 11 patients had Spetzler-Martin grade 5 AVMs, 12 patients had grade 4 AVMs, and 14 patients had grade 3 AVMs. There were no grade 1 or 2 AVMs treated with radiosurgery. Of these 37 patients, 13 (35%) were completely obliterated on follow-up angiography. Three of the 11 (27%) grade 5 AVMs were completely obliterated. Seven of the 12 (58%) grade 4 AVMs were obliterated. Three of the 14 (21%) grade 3 AVMs have documented radiosurgical obliteration, however 8 others have had a significant decrease in size on the first posttreatment angiogram (median follow-up 14 months) and have further angiographic follow-up pending. There were 5 hemorrhages after radiosurgery, 1 was fatal and 1 resulted in permanent morbidity. Six patients have been reembolized since radiosurgery and 2 of those had their AVMs surgically resected thereafter. Only 1 patient of 6 (17%) in this series who was treated with radiosurgery alone has had documented AVM obliteration. None of 3 treated with embolization alone prior to radiosurgery have had complete obliteration. Three of the 5 patients (60%) who had only surgery prior to radiosurgery had their AVMs completely obliterated. Of the 23 patients who had all three treatments (embolization, surgery, and radiosurgery), 10 (43%) had complete obliteration of their AVMs. One patient (2%) developed moderate permanent neurological disability as a result of radiosurgery-induced necrosis. This patient did have complete obliteration of her AVM. These data support the use of radiosurgery for treatment of cerebral AVMs as part of a multimodality approach if the surgical risk of any residual AVM after embolization and microsurgical resection is deemed excessive. The adjunctive use of radiosurgery in this series resulted in the safe complete obliteration of many very difficult grade 4 and 5 AVMs. These data do not support the use of radiosurgery as the primary treatment of surgically resectable AVMs since there is a risk of interval hemorrhage and the obliteration rate is far inferior to that of microsurgical resection.

Adolescent↗
PubMed1997

Linkage of the locus for cerebral cavernous hemangiomas to human chromosome 7q in four families of Mexican-American descent.

OBJECTIVE: To determine with greater precision the map location of the locus associated with familial cavernous hemangiomas. BACKGROUND: Cavernous malformations of the brain are a significant cause of seizures, progressive or apoplectic neurologic deficit, and headache. Prevalence estimates from autopsy series vary from 0.39 to 0.9%. This disorder (OMIM #116860) can be inherited as an autosomal dominant trait with variable penetrance. Linkage to markers on the long arm of chromosome 7 was recently reported in separate reports in three apparently unrelated Hispanic kindreds as well as in two kindreds of non-Hispanic descent. DESIGN/METHODS: We examined clinically, by MRI scanning, and by pathologic examination of surgical specimens, members of four large Mexican-American families segregating cavernous hemangiomas of the brain. Linkage analysis was performed with use of blood specimens from morphologically proven cases. Two-point linkage analysis was performed with the MLINK program of the LINKAGE package. Multipoint analysis was performed between two markers and the disease locus with LINKMAP in the FASTLINKAGE package. Allele frequencies were set as described by the Genome Database (GDB). Maximum penetrance for the disease allele was set to 0.75. RESULTS: The highest lod score was observed for marker D7S652 with Zmax = 6.66 at theta(max) = 0.00. Multipoint LOD score analysis placed the disease locus in the 11 cM interval between markers D7S630 and D7S527 with Zmax = 9.19. Haplotype analysis is in agreement with the placement of the disease gene between D7S630 and D7S527 and further shows a minimal shared region within this interval, indicating a founder effect in the establishment of the mutation in these families. CONCLUSIONS: We confirmed the linkage of cavernous hemangioma to markers on the long arm of chromosome 7q, and the estimate of the map location has been refined to a region of shared haplotype between markers D7S630 and D7S527 in four Mexican-American families who may be descended from a common ancestor in Sonora County, Mexico.

Adolescent↗
PubMed1997

Juvenile active ossifying fibroma. Report of four cases.

Juvenile active ossifying fibroma is a rare lesion seldom seen by neurosurgeons. It originates in the paranasal sinuses during childhood, grows slowly, and encroaches on adjacent orbital and cranial compartments. In the past 3 years, four patients with this lesion were seen (three men and one woman; mean age 28 years). The clinical presentations were different with each patient: sinusitis, meningitis, periorbital pain, and a unique case of a juvenile active ossifying fibroma presenting with high-grade internal carotid artery stenosis and ischemic symptoms. Three patients were treated by transfacial approaches: two with a transfrontal-nasal approach and one with a transfrontal-nasoorbital approach. Two open resections resulted in gross-total excision and no recurrence as of the 2-year follow-up review. In the third patient, the tumor-encased carotid artery was preserved at the expense of a complete resection; that patient underwent superficial temporal artery-middle cerebral artery bypass and remains without ischemic symptoms or tumor recurrence at 2 years. The fourth patient underwent three subtotal endoscopic resections and is also without symptomatic recurrence at 2 years. Three points must be made concerning these lesions. First, the clinical and radiographic characteristics of juvenile active ossifying fibroma may not be easily recognized by neurosurgeons, which could lead to misdiagnosis and mismanagement of these lesions. Second, this tumor can encase the carotid artery and cause severe stenosis or occlusion. Third, complete resection of the tumor is required to effect a cure, and transfacial approaches, which give wide exposure of the sinuses, appear to yield better, more radical resections than endoscopic procedures.

Adult↗
PubMed1997

Redefined role of angiogenesis in the pathogenesis of dural arteriovenous malformations.

To investigate the role of angiogenesis in the pathogenesis of dural arteriovenous malformations (AVMs), 40 rats underwent common carotid artery-external jugular vein (CCA-EJV) anastomosis, bipolar coagulation of the vein draining the transverse sinus, and sagittal sinus thrombosis to induce venous hypertension. Fifteen rats underwent a similar surgical procedure, but venous hypertension was not induced. The 55 rats were divided into seven groups. Four groups, each containing 10 rats, underwent induced venous hypertension. The other three groups, each containing five rats, did not undergo induced venous hypertension. After 1, 2, or 3 weeks, dura mater was obtained from one group of hypertensive rats and from one group of nonhypertensive rats and was assayed for angiogenic activity (rabbit cornea bioassay). The remaining group of 10 hypertensive rats was not assayed to determine if sampling affected dural AVM formation. Unlike rats without CCA-EJV anastomosis, rats with CCA-EJV anastomosis had significantly increased postoperative sagittal sinus pressures (p < 0.0001). Mean angiogenesis indices were significantly greater in rats with venous hypertension than in rats without venous hypertension (p = 0.004). Dural AVMs formed in 42% of the 55 rats and facial AVMs formed in 51%. Angiogenic activity correlated positively with venous hypertension (p = 0.74). Development of dural AVMs correlated positively with both venous hypertension (p = 0.0009) and angiogenic activity (p = 0.04). These data indicate that venous hypertension may induce angiogenic activity either directly or indirectly by decreasing cerebral perfusion and increasing ischemia, and that dural AVM formation may be the result of aberrant angiogenesis.

Animals↗
PubMed1997

Bone flap fixation: a new technique. Technical note.

A new fixation technique for bone flaps is described. This technique avoids the use of hardware external to the skull in hairless areas where it may prove unsightly in patients with a thin scalp. The insertion of pins into the middle table of the skull firmly fixes bone flaps at one edge, eliminating the need for external plates at that site.

Bone Nails↗
PubMed1997

De novo formation of a central nervous system cavernous malformation: implications for predicting risk of hemorrhage. Case report and review of the literature.

The authors present a documented sporadic de novo cavernous malformation of the central nervous system (CNS) in a patient undergoing follow-up magnetic resonance imaging after resection of an acoustic neuroma. The authors believe that this is the first report of a de novo cavernous malformation in a patient without a familial history of this disease or a history of treatment with cranial radiation. The occurrence of de novo lesions invalidates the common assumption that cavernous malformations are congenital lesions. The use of this assumption to calculate bleeding risks retrospectively in patients with cavernous malformations is likely to underestimate the risk of symptomatic hemorrhage significantly. Consequently, the de novo formation of cavernous malformations may be more common than appreciated and may explain the higher bleeding rates reported in prospective compared with retrospective studies of these lesions.

Adult↗
PubMed1997

Reversed-flow saphenous vein grafts for cerebral revascularization. Technical note.

The authors sought to create a saphenous vein interposition graft to be used in cerebral bypass procedures that would be more physiologically appropriate than standard vein grafts and would provide a better match between the graft and recipient vessels at the anastomotic sites. The saphenous vein graft was prepared by lysing the valves with a valvulotome. The blood flow could then be reversed in the vein, allowing it to be used in either direction as a bypass graft. An illustrative case including angiograms that confirm good patency and blood flow through the reversed-flow bypass graft is presented. It is concluded that the reversed-flow saphenous vein graft provides a more physiologically suitable conduit than standard vein grafts. Lysis of the valves allows the graft to be used in an orientation that takes advantage of the natural tapering of the vein to produce a better match with the recipient vessels at the anastomotic sites. Minimizing diameter changes at the proximal and distal anastomoses helps reduce turbulence, which has been implicated as a cause of early graft failure and thrombosis.

Cerebral Revascularization↗