Biomedical subjects
Publications and source records attributed to R Spaziante.
An experimental trial has been realized in rabbits interposing a polytetra fluoroethylene (PTFE) graft through the left carotid artery. Patency has been compared to one obtained by utilization of vein grafts in identical conditions.
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Two cases of pituitary adenoma associated with a parasellar cyst are reported; only one similar case has been described previously. Even though such an association may be coincidental, a pathogenetic relationship between the two lesions in one of our cases may be assumed: shrinkage of the prolactin-secreting pituitary adenoma by means of bromocriptine therapy did, in fact, cause collapse of the cyst. Such an occurrence must not be disregarded in considering the therapeutic approach.
In primary or relapsing grossly cystic craniopharyngiomas most of the problems related to the neoplastic mass may be, even if temporarily, improved by reducing volume of the cyst. A major surgical approach is unjustified when the aim is only to empty the cyst contents. Drainage of the cyst cavity by means of derivative techniques may be as effective and less invasive; in combined management plans that such tumours often require, they are, therefore, useful complementary procedures that can achieve long-lasting relief of symptoms, provided that the cyst is unilocular. Technical features and indications for such methods, with special regard to the techniques of sump drainage and of tube ventriculocystostomy, are discussed on the basis of the few reported series and of 6 personal cases. Usually only palliative aims are achieved, waiting for more definitive treatment; in a few selected cases, however, they may be quite effective.
Inversion and prolapse into the sella of the superior capsule and the diaphragma sellae is the only condition that warrants, at least macroscopically, radical removal of tumors with suprasellar extension operated on via the transsphenoidal route. If this does not occur spontaneously, air can be introduced into the subarachnoid space through a lumbar spinal catheter to produce forced dissection of the suprasellar cisterns and collapse of the tumor capsule ("pumping technique"). This method permits complete removal of the neoplastic tissue. In a series of 124 transsphenoidal operations for tumors with suprasellar extension, spontaneous descent of the capsule occurred in only 26 cases. Forced dissection using air distension of the cisterns was carried out in 88 cases, with complete success in 56 cases, partial success in 20, and no effect in 12. There were no complications or unwanted side effects in any patient.
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A patient, who had undergone removal of a meningioma and the involved dura, developed Jacksonian fits in the postoperative period. There had been precocious resorption of the patch of lyophilized dura mater used to repair the dural defect and this was followed by development of a pseudomembrane adherent to the cortex. After its removal, the patient recovered completely. Activation of reactive reparative processes, proliferative action by fibroblasts, reabsorptive phenomena, new vessel formation, are the main pathological events involved in this as in similar cases, but their sequence and the precipitating cause are not easily recognizable.
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A 62-year-old man underwent percutaneous balloon catheter compression of the gasserian ganglion for typical trigeminal neuralgia. After this, a subarachnoid hemorrhage was discovered and normal pressure hydrocephalus developed, which required shunting. Although the neurological function recovered, the patient died 8 months later because of supervening hepatic insufficiency, probably caused by protracted antibiotic therapy. Such a fatal complication, the first one associated with the technique of percutaneous trigeminal compression, was perhaps predisposed by preexistent cerebral atrophy with enlargement of the subarachnoid spaces; the unforeseen piercing of the dilated trigeminal cistern probably permitted the intracranial subarachnoid diffusion of an otherwise trivial hemorrhage. The safety of the procedure may be greatly reduced in such instances.
The use of intercavernous sinus phlebography for the diagnosis and neurosurgical treatment of pituitary adenomas has enabled the collection of selective venous samplings of the inferior petrosal sinuses (IPSs), where prolactin (PRL) levels can be measured before the hormone becomes excessively diluted in the systemic circulation. In the present study, plasma PRL levels were studied in the right and/or left IPS and, simultaneously, in the peripheral circulation of: (1) normoprolactinemic patients affected with various pituitary disorders which required phlebographic procedures; (2) hyperprolactinemic patients with negative radiological and computed tomographic (CT) signs of pituitary adenomas and (3) adenomatous hyperprolactinemic patients. In the 17 normoprolactinemic patients, the plasma PRL concentration in the IPSs was significantly higher (3.5 times; p less than 0.01) than in the peripheral circulation. In the 11 hyperprolactinemic patients with negative radiological and CT signs of pituitary adenomas, the central gradient for PRL was significantly higher (2.8 times; p less than 0.05) than in the peripheral circulation. No significant difference was detected between PRL concentrations in the left and right IPSs. In the 11 adenomatous hyperprolactinemic patients, there was a significant (p less than 0.01) central gradient for PRL 3.8 times higher than in the peripheral circulation on the ipsilateral side of the tumor. Furthermore, the plasma PRL concentration in the ipsilateral IPS was significantly higher (3.4 times; p less than 0.05) than that in the contralateral sinus. In conclusion, the present study shows that a clear-cut concentration gradient exists between plasma PRL levels in the IPSs and in the peripheral circulation of normoprolactinemic and hyperprolactinemic patients with negative radiological and CT signs of pituitary adenomas.(ABSTRACT TRUNCATED AT 250 WORDS)
The authors propose a technique of opening the sellar floor during a transsphenoidal approach by means of two small bone flaps hinged sideward. Both opening and reconstruction of the sellar floor may be improved by this method, which may be used when the floor is paper-like.
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The authors describe 3 experimental techniques for the treatment of giant arterial aneurysm, based on removal of the aneurysmal pouch and reconstruction of the arterial wall. The aneurysm is realized with a venous graft implanted with end-to-side anastomosis on the common carotid artery on the rabbit. In the first experimental model it is resected along its basis; the arterial wall is reconstructed by means of a patch of dural substitute (dacron coated with silicone rubber) fixed with biological glue (human fibrine). In the second model, the experimental aneurysm is hooded with a venous graft sutured to the adventitia of the artery with four angular stitches and biological glue. The artery is then clamped, the aneurysm is resected along its basis. The median incision in the venous graft is sutured, restoring the continuity of the arterial wall. In the third model, a small artery is implanted at the bottom of the aneurysmal sac, realizing a condition similar to a collateral vessel arising from an aneurysm. In this case, too, the aneurysm is hooded by a venous graft fixed only to the adventitia of the arterial wall with the above mentioned technique. The main and the collateral vessels are clamped, and this latter is severed; the aneurysm is resected along its basis; the median incision in the venous graft is sutured, restoring the continuity of the arterial wall; the collateral vessel is re-implanted along the suture line. These techniques aim to realize the reconstruction of the arterial wall without stenosis and shortening the clamping time.(ABSTRACT TRUNCATED AT 250 WORDS)
The purpose of this study was to define the sequential changes in global and regional right ventricular function, using equilibrium gated radionuclide angiography, following transmural inferior myocardial infarction (IMI) and associated ischemic right ventricular involvement. 24 patients with IMI underwent radionuclide angiography within 72 hours of onset of chest pain; subsequent studies were done at 13 +/- 5 days and at 6 +/- 2 months. Scintigraphic evidence of ischemic right ventricular involvement was defined by depression of right ventricular ejection fraction (less than 40%) and regional wall motion abnormalities (hypo-a-dyskinesia of right ventricular free wall). Significant improvement of global right ventricular ejection fraction was observed in 15 patients at the second study, and in 21 patients at the third study. Right ventricular regional wall motion showed similar improvement from the initial to the final studies. Significant changes in right ventricular function occurred without concurrent changes in global and regional left ventricular ejection fraction. We concluded that patients with IMI and ischemic right ventricular involvement show frequently improvement of global and regional right ventricular function over time. This changes tend to occur early and without significant modifications in left ventricular function. The good prognosis observed in our patients, despite the high incidence of in hospital complications, might be related to the improvement of right ventricular function.
The authors report 40 personal cases of infratentorial hemangioblastomas and review 36 series from the literature for a total number of 1023 patients. The clinical, pathological, and surgical features of these tumors are discussed, with particular consideration of localizations outside the nervous system, multicentric tumors, recurrences, and long-term results. Although hemangioblastomas are benign tumors, their high growth potential makes their long-term development unpredictable in some cases.
A 30-year-old man with a giant fusiform aneurysm of the intracavernous segment of the right carotid artery, clinically revealed by right painful ophthalmoplegia with exophthalmos, was treated by closure of the carotid artery in the neck with two paediatric Gianturco coils. The aneurysm, which had already shown partial spontaneous intraluminal thrombosis on CT and angiography, was no longer filled and its volume progressively decreased, with almost complete recovery of the oculomotor deficits. Serial CT and angiography performed seven months after treatment demonstrated the reduction in size of the aneurysm, its exclusion from the circulation and a good supply of the intracranial vascular bed, without the necessity of an extracranial-intracranial by-pass.
Arachnoid cysts of the quadrigeminal region are rare. We report two new cases. The first is a 29-year-old woman, who had a recurrence five years after sub-total removal of the cyst wall. Initially it was communicating and was treated by a ventriculo-atrial shunt; later it became noncommunicating and direct drainage of the cyst cavity was required. The second was a 25-year-old female, successfully treated by wide removal of the cyst wall thus creating a large communication with the subarachnoid space. Diagnosis of these lesions, as regards either morphological or functional features, nowadays rests largely on CT. Choices about treatment are extremely difficult. The most radical one, namely, complete removal of the capsule, is not without risks and disadvantages. More prudent methods, such as partial removal of the capsule and/or drainage of the cyst and the ventricles, seem on the whole to be preferable, but careful pre- and post-operative evaluation of CSF dynamics are essential for a satisfactory and long-lasting outcome.
Chronic radiofrequency stimulation of the gasserian ganglion by a percutaneous electrode is a new method for treating facial pain. The authors report their simplified technique to bring the distal end of the electrode from the cheek to the neck.