摘要:

THE TECHNICAL EVOLUTION of cranial base surgery has resulted in approaches that allow more radical surgical extirpation of complex cranial base lesions. Our service has extensively applied these cranial base approaches for lesions of the cranial base. A subgroup of 100 patients who had cranial base tumors involving potential manipulation or sacrifice of carotid arteries underwent 20-minute balloon test occlusions coordinated with vascular assessments consisting of a combination of the following: 1) four-vessel cerebral angiogram with compression studies; 2) occlusion transcranial Doppler ultrasonography; 3) occlusion single-photon emission computed tomography perfusion studies; and 4) xenon-133 cerebral blood flow studies. Transient neurological deficits associated with balloon test occlusion occurred in 7 of 100 patients (7%). Subsequently, 18 patients underwent permanent carotid occlusion by endovascular detachable balloons. Delayed ischemic complications (>72 h) occurred in 4 of 18 (22%) patients. Additionally, a number of vascular complications not predicted by the balloon occlusion tests and vascular assessments were experienced. Repeat vascular assessments defined the causes and guided treatment of ischemic patients. Ischemic complications were caused by hemodynamic insufficiency, embolization, vasospasm, radiation vasculopathy, and venous anomaly. Our experience leads us to believe that no vascular assessment exists today that can predict the occurrence of vascular complications accurately. The current enthusiasm for cranial base surgery must be tempered with the sober reality that management of cerebrovascular anatomy and physiology remain significant limitations. Consideration of potential cerebrovascular complications is paramount to successful outcome and implementation of cranial base surgery.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

THE AUTHORS COMPARED the long-term recovery of sutured facial nerves after the removal of 8 neurofibromatosis-2 (NF2)-associated and 22 non-NF2 acoustic neuromas. The patients were from a series of 270 patients operated on for an acoustic neuroma between 1979 and 1989. The assessment was done with a modified House and Brackmann scale from video recordings. At least some facial movement or tone was achieved (Grade 5 or better) in all but three patients, but in none was the recovery excellent. The facial function, judged by the overall appearance in movement, recovered less in patients with NF2 (P= 0.048); a moderately good recovery (Grade 3 or better) was seen in one patient of eight with NF2, as compared with 13 of 22 with non-NF2. In conclusion, if the tumor cannot be peeled off easily from the facial nerve in patients with NF2, leaving a fragment of tumor behind is preferable to cutting and suturing the facial nerve.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

THE PURPOSE OF this study was to assess tissue changes responsible for dural enhancement on magnetic resonance imaging (MRI) and its clinical implications. A prospective surgical, histopathological, and MRI study was performed in 73 patients with various types of disease, including meningiomas (n = 29), craniofacial tumors with possible direct intracranial extension (n = 21), gliomas and brain metastasis in close proximity to the dura mater (n = 9), and a variety of nonneoplastic processes (n = 14). Contrast-enhanced MRI was obtained within 5 days before surgery and in some cases within 3 days after surgery as well. Histopathological examination of the dural specimens was performed in all 59 patients with neoplasia and in selected patients with nonneoplastic processes. Dural invasion was noted in 18 of 29 meningiomas, 15 of 21 craniofacial neoplasms, 3 of 5 gliomas, and 3 of 4 brain metastases. In these patients invasion was focal and in direct continuity with the tumors. MRI disclosed that dura invaded by the tumor had a break in the continuity of enhancement, or that there was no discernible enhancement. Association between patterns of dural enhancement and tumor invasion of dura was statistically significant (P< 0.001). The thickened-enhanced portion of the dura represented reactive changes. Postoperative enhancement was seen as early as 24 hours after surgery and was shown histologically to be associated with vasodilation and reactive changes. Conclusions from this study are: 1) dural enhancement is a nonspecific reaction and may be seen in association with many pathological conditions; 2) a fairly uniform “enhanced dura” adjacent to a tumor correlated with a dural inflammatory reaction, whereas discontinuous enhancing dura indicated dural invasion; 3) a few false-negative cases of dural invasion (one extracranial and four intracranial neoplasms) underscore that there are some limitations of contrast-enhanced MRI in predicting dural invasion by adjacent neoplasms.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

FIFTY-ONE ADULT PATIENTS with recurrent malignant gliomas were treated in a Phase II trial of multidrug chemotherapy (6-thioguanine, dibromodulcitol, procarbazine, 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea, 5-fluorouracil, and hydroxyurea). Thirty-one patients underwent radical tumor debulking, before the administration of chemotherapy. Fifty-seven percent of all patients had either an objective radiographic response or stabilization of disease after the institution of therapy. The overall median survival time (MST) was 40 weeks; it was 79 and 33 weeks for anaplastic astrocytoma and glioblastoma patients, respectively. The overall median time to tumor progression (MTP) was 19 weeks–32 weeks for anaplastic astrocytoma patients and 13 weeks for glioblastoma patients. Serious chemotoxicity occurred in 35% of patients without permanent morbidity or mortality. The factors that affected response (including disease stabilization), MTP, and MST were identified through a multivariate statistical analysis. A longer MTP was associated with higher Karnofsky scores, lower grade initial histology, lack of prior chemotherapy, greater degree of myelotoxicity, smaller postoperative tumor volumes, greater extent of surgical resection, and a local versus diffuse recurrence pattern. A longer MST was associated with higher Karnofsky scores, lower grade histology at the time of recurrence, greater degree of myelotoxicity, and lobar versus deep tumor location. Response (including disease stabilization) correlated with higher Karnofsky scores, lower grade histology (initial and current), prior lower grade histology, smaller preoperative tumor volume, longer intervals from the time of initial diagnosis, and absence of prior chemotherapy. These results suggest that, in addition to established prognostic factors such as Karnofsky scores, other factors including prior chemotherapy administration, patterns of tumor recurrence, and tumor location may be important variables to consider in future Phase II-III clinical trials. Of the treatment variables analyzed, greater surgical debulking and smaller postoperative tumor volumes were associated with prolonged MTP but not MST, and greater myelotoxicity had a positive association with all outcomes. The significance of this latter relationship and its relevance to chemotherapy dosing will require further study. Standardization in the design and reporting of clinical trials and the use of computer-assisted tumor volume calculations to assess the extent of surgical resection and the response to therapy are advocated.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

ARTERIOVENOUS MALFORMATION (AVM) draining vein pressure (DVP) may have an influence on both the natural history of the disease and treatment outcome. The purposes of this study were to assess the relationship between DVP and other clinical and physiological variables and to characterize the transmission of arterial pressure across the AVM nidus. DVP measurements were carried out during elective AVM resection with isoflurane/nitrous oxide anesthesia with arterial carbon dioxide pressure of ≈ 30 mm Hg. The gradient between the right atrium and operative measurement site was noted. Pre-excision feeding mean arterial pressure and DVP were measured with a 26-gauge needle simultaneously with systemic mean arterial pressure and central venous pressure (CVP). DVP was tested with systemic mean arterial pressure increased to ≈ 20 mm Hg with phenylephrine or CVP increased with a Valsalva maneuver. Finally, preresection and postresection DVP values were compared. Relative to the site of measurement, DVP was 7 ± 5 mm Hg at a CVP of −4 ± 5 mm Hg (n = 45). There was no influence of presentation, presence of deep venous drainage, size, location, or prior embolization on DVP. In 19 patients, DVP decreased (8 ± 4 to 5 ± 3;P< 0.05) whereas CVP increased from pre- to postresection (−4 ± 5 to −2 ± 5;P< 0.05). For the phenylephrine challenge (n = 11), there was no difference (P= 0.84) between the ΔDVP (2 ± 1 mm Hg) and the ΔCVP (2 ± 3 mm Hg). For the Valsalva maneuver challenge (n = 7), however, ΔCVP (8 ± 4 mm Hg) was greater (P< 0.02) than ΔDVP (3 ± 2 mm Hg). Feeding mean arterial pressure and DVP were positively correlated (y = 0.2x + 2.4;r= 0.59; n = 14;P< 0.05) without any apparent influence of angiographic venous stenosis. Nevertheless, transnidal pressure drop or net cerebral perfusion pressure gradient (i.e., the lowest possible perfusion pressure to which normal adjacent circulatory beds might be exposed) was inversely correlated with AVM size (y = −6.1x + 52.3;r= 0.68; n = 14;P< 0.01). Clinically relevant changes in systemic mean arterial pressure and CVP affect DVP more as a venous than as an arterial structure. Most importantly, higher feeding mean arterial pressure is associated with higher DVP, but notwithstanding, a lower transnidal pressure gradient is present in larger AVMs. A lower transnidal pressure gradient, which may be associated with certain postoperative hemodynamic complications when transmitted to adjacent capillary beds, also may protect against spontaneous intranidal vessel rupture.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

IDIOPATHIC NORMAL-PRESSURE HYDROCEPHALUS remains difficult to treat. Controversy exists as to whether or not shunting can really improve cognitive functions and whether quantified intracranial pressure monitoring (ICP-Mo) can predict postoperative improvement rates. Several studies have drawn attention to the lack of a prospective study concerning the surgical outcome of this condition. We have performed such a study on idiopathic normal-pressure hydrocephalus patients shunted on the basis of ICP-Mo when “high” waves (amplitude >9 mm Hg) were present. Twenty-three patients underwent surgery. The preoperative and postoperative clinical states were assessed by a quantitative procedure blind to the ICP-Mo results. A clear postshunting improvement was seen in 96% of the patients at 1 year with a statistically significant correlation between high wave relative frequency and the grade of improvement (P< 0.05). At the same time, 66.6% of shunted patients showed a significant improvement in cognitive functions. Complications of shunting were successfully managed without residual deficits in this series. We recommend the use of quantitative ICP-Mo as a criterion for surgery and to predict the improvement grade.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

SEVEN CHILDREN AGED birth to 17 years with spinal cord injury without radiographic abnormality (SCIWORA) were studied with magnetic resonance imaging (MRI) between 3 hours and 16 days after the injury. There were six cervical cord injuries and one thoracic cord injury. The MRI findings were divided into two groups: extraneural and neural. The extraneural findings included one case of anterior longitudinal ligament disruption and anterior C6-C7 disc herniation associated with hyperextension; one case of posterior longitudinal ligament disruption and C2-C3 disc herniation associated with lateral flexion; and one case of C6-C7 disc abnormality consistent with increased water content occurring with hyperflexion. These ligament and disc injuries did not correlate with late instability. The neural MRI findings included one case of cord transection with rostral cord stump hemorrhage and one case of hemorrhage involving the majority of the cord's transverse diameter, both associated with permanent complete cord injuries; one case of hemorrhage involving a minor portion of the cord and of the brain stem's transverse diameter associated with a severe partial cord injury but subsequent incomplete improvement; one case of edema without hemorrhage associated with Brown-Séquard syndrome and subsequent incomplete improvement; and three cases of normal cord signal and outline. Two of the latter patients had mild cord injuries that recovered completely. In the third, a child with complete T12 sensorimotor paralysis at presentation, the normal MRI findings predicted the subsequent complete recovery. No extraaxial compressive lesion was demonstrated in these seven children. The authors conclude that in SCIWORA, 1) the demonstration of ligament and disc injuries supports the hypothesis that the cord injury is secondary to sprain or partial tearing of stabilizing ligaments, allowing excessive intersegmental displacements; 2) these ligament and disc injuries are highly correlated with the mechanisms of injury, but not with the development of overt instability; 3) the MRI findings for the cord are highly correlated with the prognosis (cord transection and major hemorrhage with poor outcome; minor hemorrhage or “edema only” with moderate to good recovery; and absence of abnormal cord signal with complete recovery); and 4) MRI is not likely to alter the acute management of childhood SCIWORA except when progression of the initial deficits suggests extraaxial cord compression.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

CLINICAL STUDIES INDICATE variations in intravertebral pressures in patients with and without low back pain. It is known that not all patients with back pain have abnormal lumbar radiographs and, furthermore, microfractures of the endplate may be one of the causes in the origin of low back pain. Consequently, this study was conducted to determine the interrelationship between microtrauma and intraosseous pressures in the lumbar spine. Miniature pressure transducers were inserted into the vertebral bodies and spinous processes of human cadaver spinal units. Radio-opaque medium was injected into the nucleus to fluoroscopically monitor the movement of the fluid from the disc as the preparation was loaded up to the initiation of microtrauma (before reaching the ultimate load-carrying capacity). The onset of injury was evidenced by the microfracture of one of the two endplates and impregnation of the contrast medium into the spongiosa. After relaxation, another cycle of loading was applied by limiting the deflections to the maximum compression sustained under the intact configuration. The load, stiffness, and energy-absorbing capacities were lower (P< 0.05) for the injured specimen compared with the intact configuration. The intraosseous pressures were higher (P< 0.05) in the vertebral body and the spinous process of the vertebra where the endplate exhibited microtrauma in the injured cycle compared with the intact cycle. In contrast, the intraosseous pressures in the vertebral body and the spinous process at the level where the endplate remained intact were not significantly different between the two cycles of loading. These findings suggest that the pressures at one level are not affected by the pressures caused by the onset of microtrauma at the other spinal level. Furthermore, because the pressures in the spinous process and vertebral bodies demonstrated similar tendencies before and after microtrauma, it should be possible to monitor the pressures in either component of the vertebra. This finding may be clinically applicable, because it is a relatively simple procedure to monitor spinous process pressures as opposed to vertebral body pressures in vivo.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

TO INVESTIGATE THE conditions that have developed in the treatment of posttraumatic meningitis with the use of new antibiotics, the authors studied cases with this infection retrospectively for a period of 68 months. Among 860 patients with moderate to severe head injuries, 12 (1.39%) sustained this complication. Of these, nine patients (75%) had a demonstrable basilar skull fracture and seven (58.3%) presented obvious rhinorrhea. Of these seven, four (57.1%) were treated conservatively and three (42.8%) finally underwent surgery for dural repair. The infecting agents were Gram-positive cocci (Staphylococcus haemolyticus,Staphylococcus warneri,Staphylococcus cohnii,Staphylococcus epidermidis, andStreptococcus pneumoniae) in five patients and Gram-negative bacilli in six patients (Escherichia coliin two,Klebsiella pneumoniaein two, andAcinetobacter anitratusin two). In one patient, the culture results were negative. All Gram-negative strains appeared resistant to ampicillin and third-generation cephalosporins, but sensitive to imipenem and to the quinolone ciprofloxacin. Gram-positive strains were sensitive to vancomycin. Hydrocephalus finally developed in the two patients who had received intrathecal infusions of amikacin. No other report of the relation of intrathecal infusion of antibiotics and the development of hydrocephalus was found. All patients survived, indicating that, for the present, posttraumatic meningitis is a nonfatal complication of head injury.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

MULTICELLULAR TUMOR SPHEROIDS were directly initiated in vitro from the biopsy specimens of a patient who is alive and who has had no neurological changes in 7 years after the gross removal of a glioblastoma. The spheroids were studied alone and in confrontation with aggregates of fetal rat brain tissue. Both in the biopsy and in the tumor spheroids, a very high proportion of cells were proliferating, as flow cytometric deoxyribonucleic acid measurements showed that 40% of the cells in the biopsy specimens and in the tumor spheroids were in the S and G2M phases of the cell cycle. Despite this high proliferation rate, the volume of the spheroids decreased, indicating an even greater cell loss. Light and scanning electron microscopic studies also indicated cell death in the spheroids. This behavior may be related to the long-time survival.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID