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Biomedical subjects

W F Chandler

Publications and source records attributed to W F Chandler.

At least 91 records · Page 5Linked to original sources
PubMed1983

Unusual abdominal complications of ventriculo-peritoneal shunts.

Placement of ventriculo-peritoneal (VP) shunts is an established procedure for treatment of hydrocephalus. With increasing longevity following successful treatment, complications are becoming more common. The authors reviewed 350 VP shunts in 242 patients and found five uncommon complications relating to the peritoneal end of the catheter: (a) cerebrospinal fluid (CSF) pseudocyst of the lesser sac, (b) subphrenic CSF loculation, (c) bowel perforation and formation of a CSF-enteric fistula, (d) intrathoracic migration of the tip of the shunt, and (e) intractable CSF ascites.

Adult↗
PubMed1983

Early versus delayed heparin reversal after carotid endarterectomy in the dog. A scanning electron microscopy study.

The present study investigates the hematological reaction to arterial injury during the first 10 minutes after endarterectomy in dogs to determine if heparin reversal during this early period predisposes to thrombus formation. Known platelet physiology would predict that heparinization during this early period would be useful to allow a fibrin-free platelet monolayer to form. After systemic heparinization (145 mu/kg) of the experimental animals, 42 endarterectomies were performed. Blood flow was then resumed for specific periods of time, and the vessels were prepared for scanning electron microscopy. Group 1 vessels (from the unheparinized control group) revealed mural thrombus formation after 10 minutes of blood flow. Group 2 vessels revealed the progressive formation of a fibrin-free platelet monolayer after 2, 5, or 10 minutes of blood flow resumption under systemic heparinization. Group 3 arteries, harvested at 10 minutes, underwent immediate (within 1 to 2 minutes after resumption of flow) heparin reversal with protamine sulfate, and demonstrated numerous patches of fibrin covering the platelet monolayer. Group 4 arteries, studied after 3 hours of blood flow, also underwent immediate heparin reversal. Two of these seven specimens had clumps of fibrin overlying the platelet monolayer. The Group 5 vessels had heparin reversal at 10 minutes, and demonstrated no fibrin overlying the platelet monolayer after 3 hours of blood flow. This study demonstrates the formation of a fibrin-free platelet monolayer over the endarterectomized vessel wall within 10 minutes of resumption of flow under systemic heparinization. These findings suggest that heparin may safely be reversed following a carotid endarterectomy if one awaits the initial critical 10 minutes of blood flow.

Animals↗
PubMed1983

Surgically reversible hypothalamic hypopituitarism due to aqueductal stenosis. Case report.

A 13-year-old girl was referred for evaluation of the deceleration in her rate of linear growth, an arrest in the progression of her pubertal maturation, and bifrontal headaches. Detailed endocrinological and radiological studies revealed the following abnormalities: partial growth hormone deficiency, prepubertal luteinizing hormone and follicle-stimulating hormone responses to exogenous gonadotropin-releasing hormone, aqueductal stenosis with obstructive hydrocephalus, and marked focal dilation of her third ventricle. Ventriculoperitoneal shunting resulted in increased linear growth, resumption of pubertal development, and correction of her documented neuroendocrine abnormalities.

Adolescent↗
PubMed1983

Abdominal complications of ventriculoperitoneal shunts with emphasis on the role of imaging methods.

Four hundred ventriculoperitoneal shunt procedures in 280 patients were retrospectively evaluated regarding complications relating to the peritoneal end of the catheter. There were 100 complications requiring 120 surgical revisions. Common complications consisted of mechanical shunt malfunction in 28, catheter tip occlusion in 40 and shunt infection in 25. In addition, there were abdominal cerebrospinal fluid loculations and pseudocysts formation in seven patients, intestinal perforation, migration of shunt tip in the right pleural cavity and intractable ascites in one patient each. The currently available diagnostic imaging modalities by which the peritoneal end of a malfunctioning ventriculoperitoneal shunt can be evaluated are reviewed.

Abdomen↗
PubMed1982

Ocular toxicity associated with high-dose carmustine.

The ocular side effects of carmustine (a nitrosurea) are not well established. Evidence of delayed bilateral ocular toxicity developed in two of 50 patients treated with high dose intravenous (IV) carmustine (800 mg/sq m) with autologous bone marrow rescue. Symptoms or signs of ocular toxicity became apparent four weeks following IV treatment. Evidence of delayed ocular toxicity ipsilateral to the side of the infusion developed in seven of ten patients treated with intra-arterial carotid doses of carmustine to a cumulative minimum of 450 mg/sq m in two treatments. The ocular toxicity began two to 14 weeks (mean, six weeks) following intra-arterial treatment. In three of these patients, the visual loss progressed over one week to no light perception. The funduscopic manifestations of both groups included arterial narrowing, nerve fiber-layer infarcts, and intraretinal hemorrhages. Fluorescein angiography demonstrated segmental perivascular staining, wide-spread late capillary leakage, and optic disc hyperfluorescence. One patient had light and microscopic confirmation of cilioretinal artery occlusion and choroidal fibrin thrombi.

Adult↗
PubMed1982

Symptomatic congenital spinal stenosis in a child.

A case of congenital lumbar stenosis producing lower extremity spasticity and bladder dysfunction in a young child is presented. Myelography demonstrated a marked stenosis of the spinal canal at L-2, L-3, and decompressive laminectomy resulted in a marked improvement in symptoms. A discussion of lumbar stenosis in general illustrates that is is extremely rare for this condition to become symptomatic during childhood. The literature on congenital lumbar stenosis is reviewed.

Adolescent↗
PubMed1982

New implantable continuous administration and bolus dose intracarotid drug delivery system for the treatment of malignant gliomas.

A totally implantable system for the continuous and bolus delivery of intra-arterial chemotherapeutic agents to patients with malignant gliomas is described. The system utilizes an Infusaid pump (Infusaid Corp., Sharon, Massachusetts), which discharges the drug directly into the internal carotid artery and is percutaneously refillable. This system has been utilized experimentally in primates and in the treatment of six patients with malignant gliomas. It seems that this system can be utilized safely as an experimental technique in the treatment of malignant gliomas.

Adult↗
PubMed1982

Intraoperative sonography for brain tumor localization and ventricular shunt placement.

Intraoperative sonography using portable real-time equipment at the dural or brain surface in 16 patients provided accurate localization of a variety of brain lesions for direct dissectional or needle aspiration biopsies as well as for decompression of cysts. The technique has proven to be reliable and rapid, reducing brain exploration in the search for small or poorly accessible lesions and eliminating complex stereotactic procedures. Ventricular shunt catheter placement was also monitored intraoperatively in two infants.

Adolescent↗
PubMed1982

The effect of heparin reversal after carotid endarterectomy in the dog. A scanning electron microscopy study.

The purpose of this study was to determine reversal of heparin, immediately after carotid endarterectomy would have an adverse effect on the thrombogenicity of the endarterectomized vessel wall. After systemic heparinization, unilateral common carotid endarterectomies were performed under the operating microscope on 14 dogs. Half of the animals were given protamine sulfate to reverse the heparin. Three hours after resumption of blood flow, these arteries, as well as contralateral vessels used as controls for fixation technique, were perfused with glutaraldehyde and prepared for scanning electron microscopy (SEM). Thrombin clotting times were measured throughout the experiments. Sections of the endarterectomized portions viewed by SEM showed nearly total coverage of the exposed collagen of the media with flattened platelets. There were scattered leukocytes, but few erythrocytes, little fibrin, and no true thrombus. There were no difference between the animals that received heparin reversal and those that did not. A group of five additional arteries underwent the same procedure except that no heparin was given. As expected, large amount of thrombus had formed within the lumina of these control vessels by 3 hours. Since previous studies suggest that arterial thrombosis usually occurs within 3 hours of endothelial injury, the authors conclude that total reversal of heparin does not increase thrombogenicity of the endarterectomized vessel. This suggests that heparin may be safely reversed in patients to help maintain postoperative hemostasis.

Animals↗
PubMed1982

Intraoperative use of real-time ultrasonography in neurosurgery.

The authors' experience with the intraoperative use of real-time ultrasonography during 21 neurosurgical procedures is reported. These procedures include neoplasm surgery in 18 cases, treatment of an arteriovenous malformation in one case, and ventricular catheter placement for hydrocephalus in two cases. In each of the neoplasm cases, the tumors were imaged just as well through the intact dura as on the brain surface itself. There were no cases in which the pathology could not easily be identified. The use of portable intraoperative ultrasonography in sterile coverings has proven to be extremely useful in localizing small subcortical neoplasms, as well as locating the solid and cystic portions of deep lesions. It has assisted in guiding needles for both biopsy and aspiration. It has also accurately identified and guided Silastic catheters during their placement in the ventricular system in cases of hydrocephalus. The authors have found real-time ultrasonography to be an important new tool in the operating room and will continue to rely on its imaging ability during selected procedures in the future.

Adolescent↗
PubMed1981

Choroid plexus cyst in the lateral ventricle causing obstructive symptoms in an adult.

This case of a rare symptomatic choroid plexus cyst in the lateral ventricle, which presented with papilledema and decreased vision, is the first such lesion found in an adult. Five earlier reported cases, all in children, are discussed, as are the limitations of computerized tomographic (CT) scanning and the need for further radiological studies to establish the diagnosis preoperatively. Metrizamide ventriculography with CT scanning is used to define the lesion and plan an operative approach.

Adult↗
PubMed1981

Flow-regulated continuous spinal drainage: technical note with case report.

A new method for continuous external drainage of cerebrospinal fluid (CSF) for the treatment of CSF fistulas is described. In this system, CSF is withdrawn continuously from the lumbar subarachnoid space at a controlled flow rate calculated to be slightly less than the natural absorption rate of CSF. Controlled spinal drainage can be achieved using equipment readily available in most intensive care units. This system was developed to prevent pneumocephalus during CSF drainage, as illustrated in the case presentation.

Adult↗
PubMed1981

Vertebral artery disease: radiological evaluation medical management, and microsurgical treatment.

The neuroradiological evaluation, perioperative medical management, and microsurgical treatment of variously located vertebral artery lesions are presented. Four types of surgical procedures were undertaken: proximal vertebral artery to common carotid artery end-to-side anastomosis; external carotid artery to midcervical vertebral artery end-to-side anastomosis; external carotid artery to distal cervical vertebral artery end-to-end anastomosis; and occipital artery to posterior inferior cerebellar artery end-to-side anastomosis. Each case is used to demonstrate the evaluation and management involved, the type of and rationale for the surgical procedure selected, and the patency of the anastomosis performed. Two points are emphasized. One is that, after careful angiographic evaluation and improved perioperative medical management, lesions of the vertebral artery are indeed amenable to microsurgical intervention with relatively low risk to the patient. The other is that, whenever possible, anastomosis of the largest caliber of vessels with the least number of suture lines is the surgical treatment of choice.

Carotid Arteries↗
PubMed1979

Hysteresis in the relationship between cerebrospinal fluid absorption minus formation and cerebrospinal fluid pressure in the dog.

In this study the difference between cerebrospinal fluid (CSF) absorption and formation (A -- F) was measured as a function of CSF pressure in the living and dead dog. We determined this relationship between A -- F and CSF pressure during both increasing and decreasing CSF pressures. A hysteresis effect was identified in 78% of living animals, but was not seen in the dead animals. This suggests that the mechanism of CSF absorption in the living dog is nonpassive and pressure-sensitive.

Absorption↗
PubMed1979

Syringomyelia presenting as a mass lesion of the conus medullaris.

A case is presented of a young girl with syringomyelia presenting as a mass lesion of the conus medullaris. Computerized tomography of the cerical spinal cord revealed asymptomatic extension of the syrinx to that level. Seven other similar cases are reviewed, and suggestions made for preoperative diagnosis of this unusual entity.

Adolescent↗
PubMed1976

Monitoring and control of intracranial pressure in non-traumatic encephalopathies.

Fifteen patients with non-traumatic encephalopathies underwent continuous monitoring of intracranial pressure. These included 11 children with Reye's syndrome, two with viral encephalitis, one with mushroom poisoning, and one with hypoxia from drowning. Elevated intracranial pressure was treated with decadron, hyperventilation, hyperosmolar agents and in some cases hypothermia and barbiturates. The results are discussed.

Adolescent↗