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Biomedical subjects

P R Cooper

Publications and source records attributed to P R Cooper.

At least 55 records · Page 3Linked to original sources
PubMed1993

A new method of thoracic and lumbar body replacement for spinal tumors: technical note.

Anterior decompressive procedures have gained more widespread usage in the treatment of anterior compressive lesions of the spinal cord due to neoplasms. Alternative methods of vertebral body replacement that use a modified silastic tube placed into adjacent vertebral segments and filled with methyl methacrylate cement are described. The technique is reserved for patients with limited longevity as the result of the malignant nature of their disease process.

Bone Cements↗
PubMed1993

Sigmoid diverticular perforation in neurosurgical patients receiving high-dose corticosteroids.

Perforation of colonic diverticula is a complication of corticosteroid use that has not been described in the neurosurgical literature. Between 1987 and 1992, 719 patients who underwent surgery for primary and metastatic brain and spinal tumors of the central nervous system received 2246 to 4936 mg of methylprednisolone given over at least 7 days. Five patients in this group (all men, ages 50-69 yr) experienced a sigmoid diverticular perforation at a mean dose of 3947 mg of methylprednisolone (range, 2240-6160 mg). Of these five, two had a known history of diverticular disease. In contrast, during this same period, 3749 patients who underwent neurosurgical procedures for non-neoplastic conditions did not receive corticosteroids and experienced no colonic perforations. All five patients with colonic perforations presented with abdominal pain and had free intraperitoneal air that was revealed on radiographs of the abdomen. Perforation of a sigmoid diverticulum was confirmed in all five at exploratory laparotomy. Four patients had good outcomes, and one died. We conclude the following: 1) patients over age 50 who receive high-dose corticosteroids are at risk for sigmoid colonic perforation, and these medications should be used with caution in such patients; 2) if possible, lower total doses of perioperative corticosteroids should be used in patients with known diverticular disease; and 3) because corticosteroids mask many of the inflammatory signs of perforation, this diagnosis should be considered in any patient with abdominal discomfort, fever of unknown origin, or unexplained leukocytosis.

Abdomen, Acute↗
PubMed1993

Posterior stabilization of the cervical spine.

Operative management of the patient with cervical spinal instability depends on the specific anatomy and location of the injury. The unique features of the atlanto-axial complex require stabilizing procedures that are quite different from those used in the subaxial spine. A clear idea of the etiology of the instability, a definition of the pathological anatomy, and knowledge of the presence and extent of neural compression are essential for optimizing a successful outcome. In some instances the clinical circumstances mandate the use of an anterior approach, and in others a posterior operation is more appropriate and likely to be successful. In the majority of patients instability can be successfully managed utilizing either an anterior or a posterior approach. Even when a posterior approach is used, there is usually more than one surgical option. It cannot be emphasized too strongly, however, that the surgeon should choose the procedure with which he or she is most comfortable and which he or she is technically able to perform. It makes little sense to attempt a procedure such as C1-C2 transarticular screw fixation or posterior cervical plating without having had "hands on" experience with cadavers or anatomical models or having previously assisted in the procedure. Wiring and other means of fixation, although "less modern," have been used successfully for many years and are usually quite satisfactory if the surgeon is experienced and comfortable in their use.

Atlanto-Axial Joint↗
PubMed1992

Delayed traumatic intracerebral hemorrhage.

Delayed traumatic intracerebral hemorrhage refers to the appearance of hemorrhage (usually within 48 hours of head trauma) in areas of the brain that were normal in appearance or nearly so on the CT scan taken shortly after injury. Neurologic deterioration is common but is not universally the rule. The frequency of delayed traumatic intracerebral hemorrhage is variable but is reported to occur in 1% to 8% of patients with severe head injury. The pathogenesis is multifactorial and may result from one or more of the following: coagulation abnormalities, necrosis of blood vessels in areas of brain injury, dysautoregulation, and release of tamponade effect with evacuation of extra-axial hematomas. Outcome is poor, and most series report a mortality of 50% or higher.

Brain Injuries↗
PubMed1990

Extracranial repair of cerebrospinal fluid fistulas: technique and results in 37 patients.

Although neurosurgeons have traditionally preferred intracranial repair for the management of cerebrospinal fluid (CSF) fistulas, this approach is associated with the complications of a craniotomy, anosmia, and a high incidence of recurrent fistulas. Extracranial repair, on the other hand, produces no central nervous system morbidity, preserves olfaction, and is associated with a low incidence of recurrence. Although there have been several reports of extracranial repair of CSF fistulas by otorhinolaryngologists, this approach has received scant mention in the neurosurgical literature. We report here our experience with 37 patients with CSF rhinorrhea or otorrhea who underwent extracranial repair. The etiology of the fistula was postoperative in 22, traumatic in 6, and spontaneous in 9. The fistulas were repaired using one of four techniques: external ethmoid-sphenoid in 18 patients, transmastoid in 9, transseptosphenoid in 7, and osteoplastic frontal sinusotomy in 3. In 32 of the 37 patients (86%) the fistulas were successfully repaired with the initial procedure. Of the 5 patients requiring a second operation, the fistula was successfully closed in 4 for an overall success rate of 97%. Complications were few and consisted of a transient facial paresis in a patient undergoing transmastoid repair and one death from meningitis. The authors conclude that because of low morbidity and mortality and a high success rate in closing fistulas, extracranial repair is the preferred technique for the operative management of CSF rhinorrhea and otorrhea.

Cerebrospinal Fluid Otorrhea↗
PubMed1989

Outcome after operative treatment of intramedullary spinal cord tumors in adults: intermediate and long-term results in 51 patients.

The reported results of treatment of intramedullary spinal cord tumors (IMSCT) are difficult to interpret because of heterogeneous management strategies, small numbers of patients, and short periods of follow-up. In 1985 we published the early results of operative treatment of 29 patients with IMSCT and were cautiously optimistic that aggressive operative management would have a salutary effect on long-term outcome. In this report, the most recent clinical status of these 29 original patients is reviewed along with that of 22 additional ones, to assess the intermediate and long-term results of treatment of IMSCT in 51 patients who underwent microsurgical resection between 1981 and 1987. Of these 51 patients, 24 had ependymomas, 18 had astrocytomas, and the remainder had a variety of less common lesions. Thirty-seven patients survive and have been followed for periods up to 72 months (mean 38 months). The neurological conditions of 21 patients are improved or have stabilized following operation. The conditions of 16 patients are worse postoperatively: 11 from operation and 5 from progression of disease. Eight patients are neurologically intact, 7 walk independently but abnormally, 9 ambulate with the aid of a cane or walker, and the remaining 13 are not ambulatory. Twelve of 18 patients with astrocytomas and 2 of 24 patients with ependymomas have died after a mean survival of 10 months from operation. Patients with ependymomas who had gross total resection have fared the best, with no deaths or recurrences, but no relationship could be discerned between the extent of resection and outcome in patients with astrocytomas.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Posterior stabilization of cervical spine fractures and subluxations using plates and screws.

Posterior stabilization of cervical spine fractures and subluxations with metal plates and screws is commonly used in Europe, but has rarely been employed by neurosurgeons in North America, where stabilization has usually been achieved with wires supplemented by bone grafts or acrylic. The limitations of the more commonly used stabilization techniques include the failure to achieve rotational stability, the necessity for intact laminae, and the requirement for bone grafting. We therefore examined the efficacy of posterior cervical plating in 19 patients who had posttraumatic instability of the cervical spine between C3 and C7 without residual spinal cord compression and 1 patient who had a subluxation as a result of osteomyelitis. Two patients had no neurological deficit, 4 had partial deficits, and 14 had no neurological function below the level of injury. Operation was performed after patients were medically stable and maximal reduction of fractures was achieved (usually within 48 hours). The plates are made of vitallium and contain two or three holes 13 mm apart through which 16-mm screws are placed bilaterally into the center of the articular masses of two or three adjacent vertebrae to stabilize one or two motion segments. Bone grafting is not performed. Patients are mobilized on the day after operation in a Philadelphia collar, which is worn for 3 months. Fourteen patients had stabilization of one motion segment and 6 had stabilization over two motion segments. The mean follow-up is 9.2 months. In a single patient with ankylosing spondylitis, plate fixation failed when screws pulled out. No patient experienced neurological deterioration as a result of the operative procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

The "hyperacute" extraaxial intracranial hematoma: computed tomographic findings and clinical significance.

Thirteen patients with acute subdural and epidural hematomas were found to have fresh, unclotted blood at the time of surgical decompression several hours after injury. Computed tomographic (CT) scans of these patients demonstrated areas of hyperdensity, corresponding to clotted hematoma, admixed with areas of isodensity, corresponding to liquid blood. Active bleeding from identifiable loci was found in 11 patients, 4 of whom had massive hemorrhages. Clotting abnormalities ranging from slightly elevated laboratory test results to a full-blown clinical picture of disseminated intravascular coagulation occurred in 8 patients. We describe the CT pictures of these "hyperacute" lesions, and we postulate that such CT presentations indicate either the presence of ongoing active intracranial bleeding or the onset of a coagulopathy complicating the management of these lesions.

Adolescent↗
PubMed1985

Visual recovery after transsphenoidal removal of pituitary adenomas.

We reviewed the records of 100 consecutive patients with histologically verified pituitary adenomas who underwent transsphenoidal decompression of the optic nerves and chiasm. The patients' ages ranged from 18 to 80 years, with a median of 52 years. Preoperatively, all patients had objective signs of visual acuity or field defects. Postoperatively, visual acuity was normal or improved in 79% of the eyes and the visual fields were normal or improved in 74%. The visual outcome (for both acuity and fields) was better in younger patients and those with a shorter duration of symptoms. Patients with lesser degrees of preoperative visual acuity compromise had better postoperative visual acuity outcome. However, the severity of preoperative visual field defects did not seem to predict postoperative field outcome, and even patients with severe preoperative field defects often had striking postoperative improvement. Patients who had undergone prior operation were less likely to have either visual acuity or visual field improvement after reoperation. Postoperative deterioration in visual acuity was noted in only 5 patients (6 eyes). Complications were few. There were 4 instances of cerebrospinal fluid rhinorrhea, but only 2 patients needed operative repair. There was no instance of permanent diabetes insipidus, although 17 patients developed transient diabetes insipidus. In most cases, visual improvement was sustained. The average duration of follow-up was 26 months. Three patients required a subsequent operation to correct visual loss in the immediate postoperative period, but only 1 patient has undergone late operation for recurrence of tumor. There was no operative mortality.

Adenoma↗
PubMed1985

Radical resection of intramedullary spinal cord tumors in adults. Recent experience in 29 patients.

The management of patients with intramedullary spinal cord tumors is controversial. In the past, these tumors have often been treated with biopsy or subtotal removal followed by irradiation--a therapy that is usually associated with early tumor recurrence and progressive neurological impairment. In an attempt to improve on the outcome of patients with intramedullary tumors, the authors performed radical resection in most of the 29 adult patients who had surgery for these tumors within the past 30 months. The mean duration of symptoms was 9 1/2 years, and all patients presented because of progressive neurological deficit. Patients were evaluated with metrizamide myelography-computerized tomography scanning and intraoperative ultrasound imaging to define the site of the tumor and cystic components. There were 14 ependymomas, 11 astrocytomas, two lipomas, and one case each of intramedullary fibrosis and astrogliosis. Solid tumor spanned a mean of five spinal cord segments and 16 tumors were associated with cysts. Twenty tumors were in the cervical and/or cervicothoracic regions. Total removal was achieved in 14 patients and "99% removal" in seven others. In 21 of 29 patients (72%), the neurological condition was stabilized or improved as a result of the operation. Postoperative deterioration occurred for the most part in patients who could not walk or who had minimal motor function at the time of operation, and these patients are no longer considered as operative candidates. Radical resection of intramedullary tumors can be achieved, with stabilization or improvement of neurological deficit in the majority of patients.

Adult↗
PubMed1984

[Intraoperative localization of space-occupying intracranial processes using ultrasound].

During a two-year period, intra-operative ultrasonic explorations were performed in 44 patients for the purpose of localisation of intracranial masses. This facilitated accurate intraoperative assessment of the location and consistency of the mass. We consider operative ultrasound to be an invaluable adjunct to surgery of small intracerebral masses.

Brain Edema↗
PubMed1984

Evaluation of cervical spinal cord injuries with metrizamide myelography-CT scanning.

In the past, patients with injuries of the cervical spine and spinal cord have been diagnosed by means of myelography and polytomography. In an attempt to improve the radiographic evaluation of patients with cervical spinal cord injuries the authors performed computerized tomography (CT) scanning of the cervical spine following injection of metrizamide into the spinal subarachnoid space. In 23 patients with cervical spinal cord injuries, metrizamide myelography was performed via a C1-2 puncture. Myelography was used only for localization of the lesion and to determine the site of CT scanning. After myelography, CT scanning of the cervical spine in the transaxial plane was effective in determining the exact nature of compressive lesions and distinguishing the etiology among hematoma, disc, bone fragments, osteophytes, or ossification of the posterior longitudinal ligament. In several patients, metrizamide could be seen entering the spinal cord and was indicative of anatomical spinal cord disruption. In patients with fractures, CT scanning identified the site and nature of the injury without the need for turning the patient to the lateral position. In several patients with an apparently stable cervical spine, the CT scan showed apophyseal joint widening indicative of instability. The authors conclude that CT scanning of the cervical spine after the introduction of metrizamide into the subarachnoid space provides a definitive evaluation of the cervical spinal cord, the bone structures of the cervical spine, and their relationship to each other.

Adolescent↗