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Biomedical subjects

W W Maggio

Publications and source records attributed to W W Maggio.

8 recordsLinked to original sources

The value of intraoperative ultrasonography in cervical corpectomy: assessment by postoperative computed tomography.

OBJECTIVE: We assessed the value of intraoperative ultrasonography (IUS) in cervical corpectomy by using postoperative computed tomography (CT) for comparison. METHODS: Twenty patients underwent a one-, two-, or three-level cervical corpectomy. The decompression was performed in a stepwise fashion, guided in each case by IUS findings until considered adequate. Each patient underwent postoperative CT to evaluate the accuracy of the IUS in guiding the decompression. RESULTS: In the 20 patients who underwent corpectomy, IUS guided a complete lateral gutter decompression. No evidence of asymmetry and excessive bone removal was identified by IUS at the end of the procedure. IUS was not useful in assessing the adequacy of longitudinal decompression because of the absence of neural landmarks in the sagittal plane. Postoperative CT confirmed adequate decompression in all patients. The width of decompression at the posterior margin of the vertebral body ranged from 18 to 20 mm, with a mean of 19.2 mm. CONCLUSION: We conclude that IUS is helpful and reliable in performing a properly centered, thorough, lateral decompression in cervical corpectomy. A limited corpectomy can be started under visual guidance and then enlarged after IUS findings until complete decompression of the neural elements has been achieved. This approach avoids the problems of asymmetry, inadequate decompression, and excessive bony removal that could lead to endangerment of the vertebral artery and possible failure of the reconstruction. The accuracy of the IUS was confirmed in this study by postoperative CT.

Adult

Neurofibromatosis 1 mRNA expression in blood vessels.

Vascular hypertrophic lesions occur in neurofibromatosis type 1 (NF1). The role of the gene which causes NF1 in the growth and development of blood vessels is not known. mRNA expression of the NF1 gene was studied in blood vessels in the transition between intact and culture and in quiescent and proliferative conditions. The expression and alternative splicing pattern of the catalytic domain of NF1 consistently changed in proliferating cells, supporting a role for this gene in the regulation of growth of vascular smooth muscle and the vascular pathology in NF1.

Animals

Treatment of right hemispheric cerebral infarction by hemicraniectomy.

An anecdotal series of nine patients (three men and six women with an average age of 57 years) presented with progressive neurologic deterioration while on medical therapy for large right hemispheric cerebral infarction. Clinical signs of uncal herniation (anisocoria or fixed and dilated pupils, and/or left hemiplegia with right decerebrate posturing) were present in seven of these nine patients. Computerized tomography of the head confirmed mass effect from cerebral edema. It was the clinical judgment of the treating neurologists and neurosurgeons that each of these nine patients would perish unless surgical decompression of the infarcted brain was performed. Accordingly, each was treated with right hemicraniectomy and dural augmentation. Six patients demonstrated neurologic improvement on the first postoperative day. One patient, with a postoperative diagnosis of lung cancer, died 1 month after surgery. The remaining eight patients are currently living with their families with a follow-up period ranging from 5 to 25 months. Patient outcome as evaluated by the Barthel Index indicates that three individuals are functioning with minimal assistance and that the remaining six patients are functionally dependent. After rehabilitative therapy, four patients returned for elective cranioplasty. These results suggest that hemicraniectomy can be an effective lifesaving procedure for malignant cerebral edema after large hemispheric infarction.

Activities of Daily Living

Posterior cervical reconstruction with methyl methacrylate cement and wire: a clinical review.

The charts and radiographs of 20 patients who were treated for traumatic cervical instability by the Department of Neurosurgery at the University of Virginia by means of posterior reconstruction with methyl methacrylate cement and fixation wires were reviewed by the Department of Orthopaedic Surgery. Based primarily on radiographic criteria, it was found that posterior reconstruction failed to rigidly immobilize the underlying unstable motion segments in 11 patients. Four of these patients required additional surgery to correct postoperative instability. Based on this experience, cement and wire reconstructions are now recommended only when: 1) they can be limited to one cervical level; 2) No. 18 fixation wire is used; 3) wiring is performed from a facet on one side to the adjacent spinous processes; and 4) autogenous bone graft is added to the posterior elements on the side of the midline opposite the cement and wire.

Adolescent

Intracranial blastomycoma.

Although meningitis is the most common form of central nervous system (CNS) blastomycosis, solitary mass lesions are not an infrequent presentation. Four of our patients presented with focal neurological deficits as a result of single intracranial mass lesions. Only 1 had clearcut evidence of extraneural blastomycosis. One was a coal miner, another worked with soil samples, and one was an engineer for a wood pulp company. All were previously healthy and 2 had diabetes. Complement fixation and immunodiffusion tests were negative in all 4 patients, and white blood cell counts and erythrocyte sedimentation rates were normal. Wet mount of tissue obtained intraoperatively by aspiration demonstrated the organism in 2 cases, culture from a lung lesion made the diagnosis in 1 case, and stain and culture of ventricular fluid revealed the organisms in the fourth case. Multiple cultures of cerebrospinal fluid from lumbar puncture were negative. All 4 patients survived. Amphotericin B alone was curative in 2 cases; surgical removal alone was curative in 1. All 4 computerized tomographic scans revealed isodense or slightly hyperdense single mass lesions with homogeneous contrast enhancement and surrounding edema, and tumor was the preoperative diagnosis in 2 cases. Such scans should suggest CNS blastomycoma in patients from the endemic area, despite the lack of other systemic manifestations. Diagnosis nevertheless rests on the characteristic histopathologic appearance in tissues and/or culture. Solitary intracranial blastomycomas may be less rare than previously thought; at our institution, we observed 4 cases in 4 years.

Adult

Frontal sinus approach to the orbit. Technical note.

The authors have previously advocated a supraorbital approach to tumors of the orbit. In this paper, they describe a technique in which they take advantage of a large frontal sinus as a means of entering the orbit without the necessity of intracranial exposure, as required by the more conventional supraorbital approach. This is achieved without frontal burr holes, allowing for a superior cosmetic result. The anterior wall of the frontal sinus is removed, and with it the roof of the orbit as a single bone flap. A case in which this technique was used is described.

Female

Effect of CSF dilution on the blood pressure of rats with renal hypertension.

The concentration of many substances in cerebrospinal fluid (CSF) of hypertensive animals has been reported to be elevated but cause-effect relationships are unclear. Conscious adult male Sprague-Dawley rats were infused via a lateral cerebroventricle with artificial CSF or water (2 microliters/min) or were not infused. Three groups of rats were tested: rats with renal hypertension (bilateral renal artery stenosis), sham-operated controls and unoperated controls. Blood pressures of the normotensive or hypertensive animals were unaffected by a 5-hour infusion of artificial CSF or water. Urinary output of rats infused with water was increased, indicating that water infusion was efficacious in diluting CSF. Based on experiments in anesthetized rats, we estimate that water infusion diluted CSF 8-14%. These results support the opinion that altered sensitivity to, or concentration of, CSF constituents per se does not maintain hypertensive blood pressure. Furthermore, it is unlikely that CSF serves as a conduit to deliver active substances to periventricular brain sites regulating blood pressure and hydration. Excess concentration of CSF constituents in hypertension probably reflects overflow into CSF instead of a cause-effect phenomenon.

Animals