摘要:

&NA;A prospective analysis of cranioplasty, vertebral body replacement, and spinal fusion using tobramycin‐impregnated methylmethacrylate in 65 patients is presented. Cranioplastic methacrylate (1 packet) was mixed with 1.2 g of powdered tobramycin and placed into the desired location. The polymer was irrigated with bacitracin until it became solid. All patients received prophylactic medication with intravenously administered nafcillin and cephalosporin perioperatively and for 48 hours postoperatively. The follow‐up time ranged from 7 to 57 months (mean, 32.2 months). Serum tobramycin levels remained below 0.5 &mgr;g/ml in all patients tested, regardless of the time interval. Blood urea nitrogen and creatinine levels remained within normal limits in all patients, and there has been no nephrotoxicity or ototoxicity. There has been 1 infection among the 65 patients (1%) to date. It occurred in a patient who had a previously treated local infection. Cranioplasty, vertebral body replacement, or spinal fusion with tobramycin‐impregnated methylmethacrylate is safe and may reduce the incidence of infection. (Neurosurgery28:789‐791, 1991)

ISSN:0148-396X    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

&NA;A new computed tomographic‐stereotactic device that translates the operating point onto preoperative computed tomographic (CT) images, theNeuronavigator,has been developed. We have applied this system to various neurosurgical procedures to examine its usefulness. The system consists of a 6‐joint sensing arm and a 16‐bit personal computer. It projects the location of the arm tip onto a corresponding CT slice with a cursor that guides the surgeon toward the intracranial target during open surgery. The system also projects the location of the tip onto angiograms, and when used in conjunction with echography or a transcranial Doppler (TCD) flow meter, the surgeon's ability to navigate is enhanced. Sixty‐eight patients underwent operation with the Neuronavigator. The navigation system worked as the core of a multimodal three‐dimensional data base that proved to be useful during surgery. The maximum detection error was 2.5 mm, which was considered sufficient for open microsurgery. It also proved useful in designing the position of a craniotomy, in targeting deep‐seated mass lesions, and in tracing the tumor edge, which had been identified on a CT scan. When the angiogram was combined with the navigator, it became easy to identify key vessels within a small operating field. The system was also combined with a TCD flow meter. This combination makes it possible to translate the measuring point of the TCD directly into CT coordinates, improving the precision of location of the TCD probe. The Neuronavigator combines various diagnostic images into one database and effectively guides the surgeon during surgery. (Neurosurgery28:792‐800, 1991)

ISSN:0148-396X    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

&NA;In the operative resection of brain tumors, defining and locating edges of deep‐seated tumors or those with indistinct color and consistency can be difficult. This report presents a simple yet precise, alternative method, using the basic Brown‐Roberts‐Wells or Cosman‐Roberts‐Wells stereotactic frame, for placement of visual markers to aid in tumor resections. The method can also be extended to the Leksell system. Using routine computed tomographic scanning or magnetic resonance imaging after stereotactic frame application, multiple points along tumor edges were used as target points. In the operating room, standard techniques were used for the skin incision, removal of the bone flap, and opening the dura. At each target point, after opening the dura and using stereotactic coordinates and equipment, a microbiopsy forceps was used to place “micropatties” (each with a string tail) or small catheters with pledgets or catheter tips located at tumor edges. After removing the arc, the tumor resection was accomplished in a conventional nonstereotactic manner by simply following string tails or catheters to the tumor. Gross tumor edges were determined from positions of actual patties or catheter tips. These simple but accurate techniques offer the possibility of tumor resections under stereotactic guidance with equipment readily available to most neurosurgeons. The fidelity of marker placement is also maintained in relation to tumor edges despite shifts in the tumor and/or brain as cystic areas are drained or large amounts of the tumor are resected. (Neurosurgery28:801‐806, 1991)

ISSN:0148-396X    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

&NA;In this study, we evaluated the efficacy of postoperative intrathecal injections of tissue‐type plasminogen activator (tPA) in preventing cerebral vasospasm in cases with a diffuse severe subarachnoid hemorrhage. All 10 cases were graded Group 3 according to the classification of Fisher and associates, and the CT number (Hounsfield number) of the subarachnoid clot was over 75. After clipping the aneurysm and removing the clot, three cisternal drainage catheters were inserted into both sylvian cisterns and the prepontine cistern, and continuous ventricular drainage was performed routinely. Postoperatively, tPA (0.5 mg/2.5 ml) was infused as a bolus into both basal cisterns and the lateral ventricle twice daily for about 6 days. Angiography and cerebral blood flow studies using single photon emission computed tomography were performed on Day 4 or 5 and between Days 7 and 10 after onset of the hemorrhage. To date, there have been no cases that have shown angiographic vasospasm or delayed ischemic neurological deficits. This preliminary study indicates that the intrathecal bolus injection of tPA produces a marked effect on vasospasm. (Neurosurgery28:807‐813, 1991)

ISSN:0148-396X    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

&NA;Thirty‐six patients with acute spontaneous subarachnoid hemorrhage (26 caused by rupture of an aneurysm) were examined by transcranial color‐coded real‐time sonography by using a 2.25‐MHz ultrasound transducer. In 20 of these 26 patients (76%), the aneurysm could be identified by a characteristic abnormal blood flow pattern within the aneurysm in coronal and axial scanning planes by transcranial color‐coded real‐time sonography. Blood within the basal cisterns, on top of the tentorium, and within the ventricles and parenchyma was sonographically detected by increased echodensity in 75%. In addition, cerebrospinal fluid circulation disturbances and cerebral vasospasm were detected in two‐dimensional B‐mode images in 85% and 100%, respectively. In Doppler mode, intravascular blood flow velocity could be quantified. We conclude that transcranial color‐coded real‐time sonography, a new, noninvasive method for diagnosis and follow‐up of patients with subarachnoid hemorrhage, allows detection of the primary vascular lesion and monitoring of complications. (Neurosurgery28:814‐820, 1991)

ISSN:0148-396X    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

&NA;Cerebral blood flow velocity, as measured in the intracranial segment of the internal carotid artery by transcranial Doppler sonography via the transorbital route, and regional cerebral blood flow and volume in corresponding cortical areas, as measured by the hydrogen clearance technique, were recorded for eight New Zealand White rabbits subjected to infusion via the cisterna magna to elevate intracranial pressure. In the lower range of autoregulation, that is, at perfusion pressures between 80 and 40 mm Hg and even lower, the changes in cerebral blood flow velocity and cerebral blood flow showed a strong correlation (0.86) under conditions of standard pCO2(PaCO2= 35 ± 2 mm Hg). Autoregulation was exhausted at 40 mm Hg, and the cerebrovascular resistance was minimal. Below this perfusion pressure, the cerebral blood flow and volume dropped sharply, whereas the cerebrovascular resistance gradually increased, indicating that, despite the max‐imally dilated resistance vessels, intracranial hypertension causes vascular resistance to increase, possibly via blocking of the venous outflow. Our results confirmed that noninvasive and easily (even at bedside) applicable measurements of changes in cerebral blood flow velocity could be a substitute for the cumbersome and expensive isotope measurements of cerebral blood flow in patients with intracranial hypertension. (Neurosurgery28:821‐825, 1991)

ISSN:0148-396X    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

&NA;Positron emission tomography with [18F]fluorodeoxyglucose (FDG) was carried out in 24 patients with pituitary macro‐adenomas (32 studies) to assess the glucose utilization of these tumors in vivo. The adenoma metabolic index, which is the ratio of FDG uptake of tumor to a whole brain slice, was calculated. Comparisons were made between tumor uptake of FDG and hormone secretion and response to therapies. In each positron emission tomography study, the macroadenoma could be easily identified visually as an area of increased FDG uptake near the region of the sella. FDG uptakes were highest for nonfunctional adenomas, and the prolactin, growth hormone, and thyroid‐stimulating hormone‐producing groups displayed similar levels of glucose metabolism. The adenoma metabolic index for all tumors averaged 1.3, ranging from 0.3 for a thyroid‐stimulating hormone adenoma to 3.5 for a nonfunctional tumor. Tumors did not exhibit metabolic rates that could characterize the type of hormone produced. Recurrent macroadenomas displayed metabolism similar to tumors not operated on, whereas irradiated adenomas showed lower glucose uptake than nonir‐radiated tumors. Drug therapy with bromocriptine or the long‐acting somatostatin analogue octreotide also decreased the glucose utilization of the tumor. There was no correlation between the amount of hormone produced and the adenoma metabolic index when a group of tumors was analyzed. Patients scanned more than once, however, demonstrated changes in hormone levels that changed or did not change in parallel with tumor metabolism. Thus, positron emission tomography offers the potential capability for predicting and defining the growth of pituitary adenomas. This may be of particular value when plasma hormone assays and conventional imaging techniques prove inadequate for monitoring patient response to therapy. (Neurosurgery28:826‐833, 1991)

ISSN:0148-396X    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

&NA;Five infants with cloacal exstrophy underwent neurological evaluation and radiographic examination of the caudal spine shortly after birth. Each was found to have occult spinal dysraphism. Four had terminal myelocystoceles, and one had a lipomyelomeningocele. Pathological anatomy was confirmed during surgery for the release of the tethered spinal cords. The striking association between cloacal exstrophy and occult spinal dysraphism suggests a common developmental defect in the caudal pole of the embryo. A hypothesis is offered to explain this association. Terminal myelocystocele and lipomyelomeningocele appear to be part of a continuum of lesions associated with skin‐covered spina bifida. (Neurosurgery28:834‐843, 1991)

ISSN:0148-396X    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

&NA;Occipital cephaloceles in the Dandy‐Walker syndrome are not rare. To date, 28 cases have been reported. We report on 8 cases of associated occipital meningocele, totalling 16% of all patients with the Dandy‐Walker syndrome in our series. In all patients, communication existed between the posterior fossa cyst and the occipital meningocele. In 2 patients, the occipital meningocele disappeared after cerebrospinal fluid shunting and never required surgical repair. It appears that the cranial defect had ossified and resulted in self‐closure. Poor intellectual development in persons with the Dandy‐Walker syndrome is associated with the presence of other central nervous system and systemic abnormalities and not with occipital meningoceles alone. (Neurosurgery28:844‐847, 1991)

ISSN:0148-396X    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

&NA;Malfunctions of sterile shunts may result from valvular dysfunction. The cerebrospinal fluid shunt valves of 14 patients were excised during surgery for sterile shunt malfunctions. In 6 patients, the malfunction was due specifically to a valve malfunction. Cerebrospinal fluid from each valve was passed through a millipore filter, which was then stained using either hematoxylin and eosin or periodic acid‐Schiff. The stained millipore filters were examined by a neuropathologist who was unaware of the cause of the shunt malfunction. Although inflammatory cells were detected in all cases, the patients with valve malfunctions were found to have numerous macrophages and giant multinucleated reactive cells within their valves, while cerebrospinal fluid from valves that had been removed during shunt revisions for reasons other than a malfunctioning valve contained only rare mononuclear cells or macrophages. No valve contained erythrocytes, fibrinous matter, neural or glial tissue, or choroid plexus. The possible causes of valve malfunction, including infection and allergic reactions, are discussed. All patients did well after simple replacement of the valve. (Neurosurgery28:848‐852, 1991)

ISSN:0148-396X    

出版商:OVID    

年代:1991

数据来源: OVID