RESUMEN

THE SUBCHOROIDAL APPROACH has taken its place among the surgical access routes to the third ventricle. Eighteen centuries ago, in his major anatomic work, Galen detailed with astonishing accuracy the anatomy of the structures around the third ventricle and the procedure for exposing this cavity by entering the lateral ventricles and elevating its roof. Even more surprising is Galen's pioneering description of surgical maneuvers of the third ventricle in living animals in a way that anticipated the modern subchoroidal approach.

Asunto(s)

RESUMEN

According to the Iliad(Chapter XXII, Verses 322-329), Hector, while fighting his last duel, was almost entirely protected by bronze armor, with only a small area "where the clavicle marks the boundary between neck and thorax" exposed. It was precisely into this area, "the shorter way to death," that Achilles thrust his lance. This fatal wound, although covering Hector with blood, allowed the victim to pronounce a few words. In designing the Story of Achilles, his fourth and last series of drawings especially designed for tapestry weaving, Rubens depicted Achilles stabbing Hector near the midline of his neck. There is evidence that Rubens was always well acquainted with the literary sources of his pictures. It is also likely that he became familiar with contemporary editions of the Iliad that were enhanced with commentaries. Realizing that the wound depicted in his original drawing should have prevented Hector from speaking, Rubens altered the scene, then showing the lance piercing the cervical vascular bundle. The careful scrutiny for literary accuracy that was typical of Rubens' artistic behavior did not prevent an additional minor imprecision in the final tapestry. Nevertheless, his outstanding expressive power enabled him to give form to a gigantic baroque representation of the death of Hector in masterly fashion.

Asunto(s)

Asunto(s)

RESUMEN

BACKGROUND: Little information is available about the extent and the time course of possible impairment of cerebral circulation occurring after aneurysmal subarachnoid haemorrhage (SAH). The aim of this study was to correlate cerebral autoregulation, neurological impairment at surgery and timing of surgery in patients with ruptured intracerebral aneurysms. METHODS: Cortical blood flow (CoBF) was measured intraoperatively by a thermal diffusion probe in 77 patients during surgery for ruptured supratentorial aneurysms, who were operated on at different time intervals after bleeding. An autoregulation index (AI), expressed as the ratio between the change in CoBF and the change of mean arterial blood pressure at the time of rising the systemic blood pressure after occlusion of the aneurysm(s), was determined in each case. RESULTS: Among good-grade patients (WFNS grade I-II), those operated on days 0-2 after SAH had a significantly better autoregulatory response, compared either with patients who underwent surgery on days 3-7 after bleeding (p<0.01), or with those whose aneurysm was occluded more than 7 days after rupture (p<0.03). The mean AI of poor-grade patients (WFNS grade IV-V), who received surgery on days 0-2 after SAH, was significantly higher (p<0.01) compared with the corresponding value of good-grade patients. No significant difference was found between the mean AIs of patients who subsequently did, or did not, develop symptomatic vasospasm. CONCLUSIONS: It is concluded that good-grade patients operated on within 48 hours after bleeding take advantage of a preserved autoregulatory function during controlled hypotension.

Asunto(s)

RESUMEN

With the introduction of newer, more expensive psychotropic medications, pharmacists must consider the cost-effectiveness issues related to the use of these drugs. In general, the newer agents are more effective than conventional drugs, have improved side-effect profiles, and are associated with a lower rate of recidivism. However, because of cost constraints, not every patient who needs a newer psychotropic drug has the opportunity to receive it. To provide these patients with the medication they need, we must look beyond the acquisition cost of the drug and focus on the global impact of the medication on the total mental health budget at a facility. Data from this point of view can justify the greater expense of the medication, and more importantly, the patient can be better served. Cost-effectiveness data from one's own institution may be more convincing to formulary committee members than data from academic centers and can help make newer, more expensive agents available to the patients who need them. Designing and implementing a retrospective study is one means of obtaining these cost-effectiveness data.

Asunto(s)

RESUMEN

A modification of the lateral orbitotomy is reported for the microsurgical approach to tumors located in the posterior intraconal space. The orbital apex is entered through a small bone opening on the orbital and temporal portions of the greater wing of the sphenoid, with the lesser sphenoidal wing, the orbital plate of the frontal bone, and the lateral orbital rim being left intact. This surgical technique was employed in 8 cases of pure apical tumors, out of a consecutive series of 103 orbital growths. It proved to be reliable with regard to either adequate exposure and radical excision of the lesions or low rate of operative morbility.

Asunto(s)

RESUMEN

Using a monoclonal antibody specific for human tenascin (TN), 180 intracranial growths were immunohistochemically studied. In 69 cases of meningioma, neoplastic cells were negative, with some positivity being observed only in the perivascular and the supporting stroma, especially in anaplastic meningiomas. In 57 cases of glioma different degrees of reactivity occurred in both the cellular conglomerates and the stromal components of the tumours. A higher variability in reactivity was observed in anaplastic astrocytomas and glioblastomas. The most constant finding of the study was the staining of the stroma, which was observed in all types of growths, including metastasis, abscess and tuberculoma. The results are consistent with the hypothesis that tenascin is a stromal marker rather than a true marker of malignant tumours. The heterogeneous distribution of TN in anaplastic gliomas may be a factor in the variable response to treatment with radiolabelled anti-TN monoclonal antibodies.

Asunto(s)

RESUMEN

Forty-one patients with burst fractures of the thoracolumbar junction, or the lumbar spine (T12 to L5), were followed for 6-48 months (mean follow-up = 19.9 months) after early surgery (usually within 24 hours). Preoperative, early postoperative, and late postoperative degrees of kyphosis, as well as percent reduction of the height of the vertebral body were calculated and compared. Early postoperative radiologic evaluations showed a statistically significant difference (p < 0.0001) between the mean values of both parameters calculated respectively before and after surgery. The decrease of the surgical correction, from the initial postoperative radiographs to follow-up, was statistically significant (p < 0.0001). However, the final values were better when compared with the preoperative features (p < 0.003 and p < 0.0001, respectively for degree of kyphosis and reduction in vertebral height.

Asunto(s)

Asunto(s)

RESUMEN

Forty-three patients were operated on for ruptured intracranial aneurysms during a 12-month-period. Intraoperative evaluation of cortical blood flow by means of a thermal diffusion probe was performed in 23 out of the 41 patients who were operated on for aneurysms of the anterior circulation. The autoregulation index was determined at the time of raising the systemic blood pressure after clipping of the aneurysm(s). No statistically significant difference was found between the averages of the autoregulation indexes calculated in the subgroups of patients submitted respectively to early or delayed surgery. There was no correlation of both cortical blood flow and autoregulation with either age of the patients, or preoperative neurological grade. On the contrary, the autoregulation index showed a statistically significant correlation with outcome.

Asunto(s)

RESUMEN

Early changes of cerebellar and cerebral blood flow, as well as subsequent infratentorial ischaemia, were evaluated in an experimental model of cerebellar haemorrhage. Eight anaesthetized male adult Sprague-Dawley rats received an injection of autologous arterial blood (50 microliters) into the right cerebellar hemisphere. Eight animals were sham-operated and served as controls. Cerebellar blood flow, measured at regular time intervals in the hemispheric cortex ipsilateral to the lesion by the hydrogen clearance method, was significantly depressed in the experimental group as compared with the control animals. This drop in cerebellar blood flow was evident 5, 30, 60, 90, and 120 min postoperatively, with a return to pre-injection values recorded 180 min after surgery. No significant difference in supratentorial blood flow was detected over the entire period examined between the two groups of animals. Enzyme histochemistry demonstrated areas of ischaemia around the clot and within the brain stem in animals with an intracerebellar haemorrhage at the end of the experiment. These results provided evidence of ischaemic damage within the infratentorial compartment after the induction of experimental cerebellar haemorrhage.

Asunto(s)

RESUMEN

Out of a series of 43 cases operated on for ruptured intracranial aneurysms over a 12-month-period, 32 patients were followed up to 12 months postoperatively with repeated evaluations of cerebral blood flow, using the Xenon133 inhalation technique. No statistically significant differences in cerebral perfusion were detected between the subgroups of good-grade patients, who were submitted respectively to early, or delayed surgery. Depression of flow in the affected hemisphere of poor-grade patients was principally related to the preoperative occurrence of an intracerebral haematoma. The overall results were not consistent with the hypothesis that early surgical intervention results in long-lasting effects on the cerebral circulation.

Asunto(s)

RESUMEN

Twenty-seven consecutive patients with neurological impairment due to burst fractures of the lumbar spine were operated upon, via the postero-lateral route, over a 38-month-period. Transpedicular fixation devices [posterior segmental fixator (PSF) or variable screw placement system (VSP)] were applied in all cases, in order to achieve short-segment fusion of the fractured spinal segment. Return to useful motor power or neurological normality (median follow-up: 18.7 months) occurred in 22 cases (81% of the whole series), with this outcome resulting in all but one of the cases with preoperative incomplete neurological deficit. Postoperative encroachment of the spinal canal, degree of kyphotic deformity, and reduction of the vertebral height showed statistically significant differences compared with the corresponding preoperative values.

Asunto(s)

RESUMEN

Forty-seven patients, who underwent surgery over a 34-year period by the wrapping or coating of ruptured intracranial aneurysms, have been retrospectively evaluated. The following materials were used in the surgical procedures: muscle with gelatin sponge (7 cases), gauze (2 cases), oxidized cellulose with Biobond (28 cases), Histoacryl with gauze or fascia (10 cases). The patients were monitored for up to 37 years (mean, 13.7 +/- 8.2 yr). One or more subsequent bleedings occurred in eight patients (17%). Three patients had additional bleeding and died in the early postoperative phase (within 1 mo after surgery). In five patients, the subsequent bleeding occurred between 1 and 15 years postoperatively, with two fatalities. One patient experienced two recurrences. Therefore, the mortality rate for postoperative bleedings was 10.6% (five patients) in the whole series, and the incidence of early (within 1 mo after surgery) fatal bleedings was 6.4%. After the first month from the initial hemorrhage, the global risk of subsequent bleeding was 0.93%/yr. Among the nine patients whose aneurysms were wrapped with muscle, gelatin sponge, or gauze, four additional bleedings occurred, whereas four relapses were observed among the 38 cases treated by employing bioadhesive agents (P < 0.04; Fisher's exact test). The rate of further bleeding was higher (25%) in patients undergoing surgery in the premicrosurgical era compared with that (8.7%) recorded in patients treated by microsurgery (difference statistically not significant).

Asunto(s)

RESUMEN

Thirty-one consecutive symptomatic patients with burst fractures of the lower thoracic or lumbar spine (T 11-L4) were treated by early surgery in a 36-month period, with near-anatomical reduction being achieved via the postero-lateral route. Fusion and reconstruction of the vertebral body was done by using autologous or processed bovine bone. Correction of the kyphotic deformity was obtained by using distraction rods or transpedicular devices. The post-operative mean degree of kyphosis, percent vertebral height, and percent canal stenosis showed statistically significant differences, compared with the corresponding pre-operative mean values. All but one of the 25 patients with incomplete paraplegia exhibited neurological improvement, with complete recovery occurring in 20 cases (median follow-up: 16 months) irrespective of the location of the lesion at the thoraco-lumbar junction (T 11-L1) or the lower lumbar segment (L2-L4). Out of the 6 patients with pre-operative complete paraplegia, useful motor power returned in one case with a lesion below L1. The results confirm the suitability of the postero-lateral route and are consistent with the assumption that early near-anatomical reduction and stabilization favours maximum neurological recovery in symptomatic patients.

Asunto(s)

RESUMEN

The temporal progression of changes in blood flow within the hemispheric cerebellar cortex, following an experimental cerebellar ipsilateral haemorrhage, was investigated in rats by using the hydrogen clearance technique. Stereotactical injection of 50 microliters of fresh autologous blood into the paramedian white matter was found to produce an early drop of cerebellar blood flow, with subsequent rise toward higher values. An increase of the intracranial pressure only occurred at the time of injection of blood. Arterial blood gases, mean arterial blood pressure and blood glucose levels did not exhibit significant changes. Histochemical evaluations of glycogen phosphorylase showed a posthaemorrhagic pattern of enzyme depletion, consistent with the occurrence of an ischaemic damage in both the cerebellum and the brain stem.

Asunto(s)

RESUMEN

Analysis of 314 cases of penetrating craniocerebral missile injuries in civilians revealed a high rate of early mortality, with 228 victims having died at the scene and a further 38 dead within 3 hours. Surgery was performed in 44 patients who had a preoperative Glasgow Coma Score of at least 4. Out of the 26 survivors, all operated upon, 19 had an adequate recovery (score of 0-3 on the expanded Glasgow Outcome Scale). Vigorous resuscitation and early surgery often resulted in useful survivals and occasionally in spectacular recoveries. However, the high mortality rate on the scene or soon after the injury restricted the possibility of effective management to a minority of cases.

Asunto(s)

RESUMEN

The predictive value of radiological signs for the presence of lacerations of the thoracolumbar dura in spine-injured patients could represent an important adjunct to the rationale for the optimal management, owing to the possible onset of early or delayed complications of these lesions. Occurrence of signs assumed to be related to dural tears, such as separation of the pedicles, fractures of the laminae, and encroachment of the spinal canal, was analyzed in a consecutive series of 25 patients submitted to surgical reduction and stabilization of the fractured lower thoracic or lumbar spine in a 24-month period. No statistically significant correlation was found between dural lacerations and any of the examined signs. Leaks of cerebrospinal fluid through traumatic breachs of the meninges were found in 16 of the 25 cases. The high rate of occurrence of dural lesions associated with fractures of the lower thoracic or lumbar spine adds a further argument to the aggressive approach to these injuries.

Asunto(s)

RESUMEN

Autografts of peripheral nerve or allografts of muscle basal lamina were inserted into the putamen-caudate complex of rats, with the outer end of the implant being sutured to the temporalis muscle. Elongation of central axons within the grafts, as revealed by the horseradish peroxidase retrograde labelling technique, did occur in the presence of basal lamina implants. With both types of grafting materials stained neurones exhibited a comparable distribution, being mainly found in the proximity of the central tip of the grafts. However, labelled cells in the presence of basal lamina were limited in number, compared with peripheral nerve autografts. Therefore, the usefulness of implants of muscle basal lamina into the central nervous system, in order to direct regenerating central axons toward distant target regions, is limited. This material might be suitable, as an alternative grafting material, in experimental models where avoidance of neurological impairment or size and length of the graft are crucial factors.

Asunto(s)

Asunto(s)