Role of platelets in vasogenic brain edema. I. Significance of thrombus formation in the damaged vessels.

In an investigation of the role of platelets in vasogenic edema in cats, direct observation of the cortex revealed that within several minutes after cold injury, platelet thrombi formed in small veins at the point where the veins emerged from the depths of the brain. Later, edema fluid extravasated from the veins at this same point. Pretreatment with a platelet inhibitor, RA-233, abolished the formation of platelet thrombi and remarkably enhanced the leakage of edema fluid. The microcirculation was assessed by carbon black perfusion and was found to fill better in the cats that received the platelet inhibitor. The better filling may be ascribed to a decreased number of thrombi and consequent improved blood flow in small blood vessels. We conclude that platelet aggregates play a major role in controlling the leakage of edema fluid after cold injury.

Role of platelets in vasogenic brain edema. II. Contribution of platelet serotonin in brain edema.

In this study of the function of platelets after CNS injury, platelets were treated with serotonin labeled with radioactive carbon (14C) in animals subjected to a freezing lesion of the cerebrum. The distribution of platelet serotonin was measured by counting the specific activity of 14C-labeled serotonin in tissue and by autoradiography. Some of the animals were treated with RA-233, which inhibits the formation of platelet plugs after endothelial damage and the release of serotonin from platelets. Platelet serotonin accumulated near the surface of the cortex at the site of injury in all animals. More cerebral edema developed in animals treated with the platelet inhibitor than in untreated animals, probably because platelet aggregates were inhibited from forming and were not available to plug leaks in the traumatized vessels. Serotonin did not appear to facilitate the spread of edema.

Morbidity and mortality of craniotomy for excision of supratentorial gliomas.

Extensive surgical resection of supratentorial gliomas increases survival. However, some reports suggest that the perioperative morbidity and mortality outweigh the potential benefit of the procedure. We examined prospectively morbidity and mortality in 104 consecutive patients who underwent surgery for supratentorial glioma, as well as other factors that might affect the short-term outcome. To determine if our experience was unusual, we compared these results with those obtained from another academic neurosurgical center by a review of the records of 109 patients also treated surgically for supratentorial glioma. Mortality was 3.3% and the medical plus neurologic morbidity was 31.7%. Functionally significant neurologic worsening occurred in 42 (19.7%) patients. Complications were more frequent in patients with moderate or severe preoperative disabilities than those with mild or no preoperative disability. Patients with complete resection had fewer acute neurologic complications, and no greater risk of being neurologically impaired at 1 week, than patients with biopsy or less extensive procedures. Morbidity and mortality correlated with location: deep-midline lesions had a higher overall rate of perioperative complications (p = 0.032) and mortality (p = 0.019) and bilateral lesions a higher rate of hemorrhage (p = 0.017) and hydrocephalus (p = 0.010). Older patients (greater than 55 years) and those receiving high daily dose of preoperative dexamethasone (greater than or equal to 24 mg) had a significantly higher risk of surgical mortality. Reoperation for recurrent tumor carried no greater risk of mortality, neurologic deterioration, and infection than a first operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Eosinophilic products lead to myocardial damage.

Eosinophils have been associated with endomyocardial fibrosis. However, their effect on the myocardium and the reactions they elicit have not been emphasized. We describe four patients with extensive myocardial eosinophilic infiltration with and without endomyocardial fibrosis. Patients with a short duration of disease had eosinophilic infiltrates, myocardial eosinophilic abscesses containing granular eosinophilic material, and/or Charcot-Leyden crystals with and without profuse histiocytic and giant cell reaction with granuloma formation. In the early phase, the granular eosinophilic material can be visualized by the Luna stain and/or by electron microscopic examination. In patients with a long duration of symptoms, well-developed granulomas and profuse fibrosis are seen and eosinophilic material may not be visualized. Toxic eosinophil granular protein may be involved in the development of these lesions.

Echocardiographic features of traumatic disruption of the aortic valve.

The echocardiographic findings are presented of a patient who had evidence of aortic regurgitation one year after blunt trauma to the chest. Combined M-mode and 2-D imaging showed features suggestive of disruption of the posterior aortic leaflet, subsequently confirmed at operation, in the absence of infective endocarditis. Diagnosis of this uncommon cause of aortic regurgitation, heretofore confirmed only by direct visualization, may be made preoperatively by echocardiography.

Cerebrovascular blockade associated with thoracotomy and its prevention with a platelet inhibitor.

Dogs subjected to a thoracotomy in which a rib-spreading retractor was employed developed filling defects in the cerebral microcirculation attributable to obstruction by microemboli. These changes were not observed in control groups and could be prevented in the experimental group by pretreatment with RA233, a platelet inhibitor. It is possible that microembolic-related complications of operations and trauma, such as pulmonary insufficiency, might be ameliorated by the use of platelet inhibitors.

Systematic screening of chromosome 18 for loss of heterozygosity in esophageal squamous cell carcinoma.

Esophageal cancer ranks among the 10 most common cancers in the world, and is almost uniformly fatal. The genetic events leading to the development of esophageal carcinoma are not well established. To identify genomic regions involved in esophageal carcinogenesis, we performed a systematic screening for loss of heterozygosity (LOH) in 24 samples of squamous cell carcinomas, initially focusing the analysis on chromosome 18. Thirteen short tandem repeat markers spanning 18p and 18q were used. We found a broad peak of LOH spanning 18p11.2 and 18q21.1 with the most frequent LOH (72%) at D18S978 on 18q12.2, which coincides with a known fragile site FRA18A. This region is 4 cM proximal to known tumor suppressor genes and therefore suggests the possible existence of a yet undiscovered tumor suppressor gene.

Evaluation of urethral strictures and associated abnormalities using high-resolution and color Doppler ultrasound.

OBJECTIVES: To study the role of urethral sonography and color Doppler imaging in the evaluation of patients with urethral strictures and associated abnormalities. METHODS: We reviewed our experience with 41 urethral sonographic studies in 35 patients and compared them to 33 retrograde urethrograms. For 6 recent cases, we also used color Doppler imaging to assess spongiosal tissue blood flow and the location of urethral arteries. RESULTS: Both retrograde urethrography and urethral sonography assessed the caliber and length of the strictures well. Urethral sonography provided additional information about stricture involvement of the spongiosum, location of urethral arteries, and associated abnormalities (that is, periurethral abscess and urethrocutaneous fistula). This information was useful for the clinical stratification of urethral stricture disease and the planning of treatment. CONCLUSIONS: With the advantages of avoiding radiation to testis, providing real-time evaluation of the distensibility of the urethra, and having the capacity of assessing spongiosum and periurethral tissue involvement and urethral artery location, urethral sonography appears to offer more than retrograde urethrography for the evaluation of anterior urethral stricture.

Surgical removal of craniopharyngiomas by the transcranial approach through the lamina terminalis and sphenoid sinus.

We describe a method of attempting total removal of a craniopharyngioma using a subfrontal approach; dissection of the tumor from the brain stem, hypothalamus, and optic chiasm through the lamina terminalis; and then piecemeal removal of the tumor through the sphenoid sinus. Eleven patients treated by this approach are reported. In these patients, prior subfrontal operation did not affect outcome, but a prior transventricular operation or prior high dose radiation therapy made complete tumor removal less likely. We believe that this operation is one way to remove a craniopharyngioma that affords satisfactory exposure and reduces the chances of injury to the frontal lobes, hypothalamus, and optic pathways.

Combined transoral and median labiomandibular glossotomy approach to the upper cervical spine.

A surgical approach to the clivus and anterior spine from C-1 to the upper part of C-5 is described. It is a direct approach that provides a wider and longer exposure than does the transoral approach. Despite the seemingly radical incision, the cosmetic deformity and functional loss are minimal. This approach is useful for the surgical treatment of a variety of processes that are situated ventral to the upper cervical spinal cord and the cervicomedullary junction.

Subchoroidal trans-velum interpositum approach to mid-third ventricular tumors.

Our experience with the subchoroidal, trans-velum interpositum approach to mid-3rd ventricular tumors is reviewed, and our operative technique is described. Excellent exposure of the mid-3rd ventricle is gained by opening the foramen of Monro posteriorly after dividing the septal vein and/or the thalamostriate vein from the ipsilateral internal cerebral vein. There has been no morbidity or mortality in eight successive cases. The principal advantage of this technique is that the fornix is preserved and memory function is not at risk.

The use of the potassium titanyl phosphate (KTP) laser in neurosurgery.

The potassium titanyl phosphate (KTP) laser recently has been introduced for use in surgery, but as yet, no data have been published concerning the safety or efficacy of use of the KTP laser in neurosurgery. A series of patients treated with the KTP laser that revealed some practical advantages of this instrument over other lasers presently available is reported. The KTP laser has been designed with user safety in mind. In general, the KTP laser, with its angled, low-profile, lightweight hand pieces, was especially useful in anatomically confined locations, where a laser beam directed from an attachment operated with a joy stick mounted on the operating microscope would prove awkward. The KTP laser provided very good hemostasis. Certain large fibrous tumors were found to be more easily removed using a combination of the KTP laser and ultrasonic aspiration rather than with either instrument alone.

Is magnetic resonance imaging useful in guiding the operative approach to large pituitary tumors?

Forty-two patients with large pituitary tumors were studied with magnetic resonance imaging scans. Based on the operative findings, the tumors were divided into two groups. Tumors in Group 1 (n = 35) were soft or partially necrotic and were easily removed by suction and curettage. Tumors in Group 2 (n = 7) were firm and required sharp dissection or use of the laser for removal. Tumors were divided into two groups based on the long TR signal: a) isointense in comparison with white matter, or b) hyperintense in comparison with white matter. All 7 firm tumors (Group 2) had an isointense signal on long TR sequences. Thirty-two of 35 soft tumors showed a hyperintense signal on long TR sequences, and 3 an isointense signal. Based on these results, we recommend a transsphenoidal approach for the initial operation in patients with large pituitary tumors. If the tumor is largely isointense on the magnetic resonance imaging scan, we discuss with the patient preoperatively the possibility (70% in this series) that the tumor may be too firm to remove in a single transsphenoidal procedure. In these circumstances, a second, transcranial, procedure may be required to decompress the suprasellar structures adequately.

Craniotomy versus transsphenoidal excision of large pituitary tumors: the usefulness of magnetic resonance imaging in guiding the operative approach.

Fifteen patients with large pituitary tumors were studied with computed tomography (CT) and magnetic resonance imaging (MRI). CT was performed using General Electric 8800 and 9800 scanners (General Electric Co., Medical Systems Division, Milwaukee, Wisconsin). MRI was performed utilizing a Technicare superconducting scanner (Technicare, Cleveland, Ohio) at 0.5 tesla. Based on the operative findings, the tumors were divided into two groups. Tumors in Group 1 (n = 12) were described by the surgeon as soft or partially necrotic and easily removed by suction and curettage. Tumors in Group 2 (n = 3) were firm and required sharp dissection or the laser for removal. The tumors were divided into four categories based on MRI signal: (a) isointense with surrounding brain on spin echo (SE) 30 and SE 90, (b) increased signal intensity on SE 30 and SE 90, (c) decreased signal intensity on SE 30 and increased signal intensity on SE 90, and (d) isointense signal on SE 30 and increased signal intensity on SE 90. All three of the firm tumors were isointense with brain on MRI appearance. The tumor consistency (firm vs. soft) was not differentiable on CT scan. The transsphenoidal approach is less satisfactory than craniotomy in cases of firm, fibrous pituitary tumors. Based on our preliminary data, if the MRI signal in the tumor is isointense, then the surgeon should be prepared to deal with a fibrous tumor and might elect a transcranial rather than a transsphenoidal approach.

Intraoperative localization of subcortical brain tumors: further experience with B-mode real-time sector scanning.

Intraoperative ultrasonography is a potentially useful tool for the neurosurgeon faced with the task of finding and removing small subcortical brain tumors. With the B-mode real-time sector scan equipment now available, satisfactory images of the intracranial contents can be obtained. Others have reported obtaining images by applying the transducer directly to the dura mater or cortex. This carries the risk of pressure damage to the brain. Furthermore, the presence of acoustical noise in the region close to the transducer results in poor image resolution in the superficial region of the cortex. To circumvent these two problems, we have used a saline-filled cylinder placed over the craniotomy site to achieve acoustical coupling. This technique also increases the area of cortex visualized by the pie-shaped beam of the sector scan by separating the transducer from the brain surface.

A code of ethics. The 1986 AANS presidential address.

More than 50 years after the founding of the American Association of Neurological Surgeons as the Harvey Cushing Society, the delineation of a Code of Ethics constitutes a milestone for neurosurgeons. The reasons for developing the Code, its historical basis, and the continuing need to reinterpret any code in view of continuing changes in neurosurgical practice and delivery of health care are discussed.

A surgical approach through the pedicle to protruded thoracic discs.

Three cases of thoracic disc herniation presenting with signs of spinal cord compression are reported. The patients were operated on by an approach through a midline incision in which a pedicle is removed. Two patients were cured and one has improved.

Cottonoid as an acoustical marker for intraoperative ultrasound scanning. Technical note.

The authors demonstrate the use of cottonoid as a marker for ultrasound localization of a subcortical tumor.

Focus of epithelial dysplasia arising in hereditary gingival fibromatosis.

The gingiva of a 32-year-old black male was biopsied for evidence of vasculitis, but instead an area of epithelial dysplasia was found. Further investigation revealed that the patient and several members of his family had hereditary gingival fibromatosis. Treatment included four quadrants of gingivectomy plus inverse bevel incisions for trimming those areas which were too thick for simple gingivectomy. Histopathologic examination of the excised tissues supported the diagnosis of gingival fibromatosis, but no other areas of epithelial dysplasia were seen. To our knowledge, this is the only reported instance of a premalignancy or malignancy arising in gingival fibromatosis, and thus there is no reason to regard the gingival disorder as predisposing to carcinoma. However, the pedigree reported here supports a previous suggestion that hereditary gingival fibromatosis is not as rare among blacks as the literature has indicated.

Usefulness of preoperative inferior petrosal vein sampling in Cushing's disease.

Adrenocorticotropic hormone (ACTH) levels from the inferior petrosal sinuses and peripheral veins were measured in 10 patients with Cushing's disease. All patients had normal or indeterminate computed tomography scans. In 9 of the 10 patients the petrosal vein sampling showed a gradient between pituitary ACTH and peripheral ACTH verifying the supposition of pituitary dependent hypercortisolism. In seven cases preoperative ACTH levels lateralized tumor to one side of the gland. In six of these cases tumor was found at that location at surgery. In the seventh case, no tumor was identified at surgery and that half of the gland was resected. Nine patients were cured following transsphenoidal excision of tumor.