Preoperative embolization of arteriovenous malformations with polylene threads: techniques with wing microcatheter and pathologic results.

The technique with a wing microcatheter system and the pathologic aspects of 11 cerebral arteriovenous malformations (AVMs) surgically resected after embolization with polylene threads are reported. Embolization was performed once in eight patients and twice in three patients. Resected AVMs were submitted both to routine hematoxylineosin examination and to immunohistochemical workup in order to detect the type of immunologic response to thread emboli. In nine cases, 50% or more of the nidus was obliterated by the embolization. After embolization two patients developed reversible neurologic deficits. Pathologic specimens of resected AVMs demonstrated no vascular necrosis; however, a moderate inflammatory response could be seen, characterized by the presence of both mononuclear cells and foreign-body giant cells, associated with the absence of polymorphonuclear infiltrates. A granulomatous fibrotic process was identified that was present from the first month after embolization. Immunohistochemistry indicated that the immunologic response to thread emboli was cell-mediated, not humoral. Embolization with the wing microcatheter with the use of polylene threads proved to be a safe and efficient system of embolization, as a preoperative procedure. Polylene threads are a nontoxic and biocompatible material that can be used as an embolic agent for brain AVMs.

Spontaneous occlusion of supraclinoid aneurysms after the creation of extra-intracranial bypasses using long grafts: report of two cases.

OBJECTIVE: We describe two cases of giant supraclinoid aneurysms, treated by means of saphenous vein grafting between the external carotid artery and the middle cerebral artery, which unexpectedly spontaneously occluded. CLINICAL PRESENTATION: Two patients presented with subarachnoid hemorrhage and headache, respectively. In the first case, angiography showed an aneurysm of the right internal carotid artery (ICA), which had been treated by clipping. Repeat angiography showed a giant aneurysm of the right ICA, the formation of which was probably caused by sliding of the clip that had been applied during the previous operation. The patient was operated on again, but it was impossible to exclude the aneurysm because no clear neck could be identified. In the second case, magnetic resonance imaging and cerebral angiography showed a large, partially thrombosed aneurysm of the supraclinoid segment of the left ICA. TECHNIQUE: In view of the patients' ages and the statuses of compensatory circulation, each patient underwent cerebral revascularization with a long saphenous vein graft placed between one branch of the middle cerebral artery and the external carotid artery, in anticipation of subsequent endovascular treatment of the aneurysm and/or closure of the ICA in the neck. Postoperative angiography demonstrated spontaneous occlusion of the aneurysms. CONCLUSION: Thrombosis of an aneurysm may occur spontaneously or after explorative surgery. However, it should be remembered that spontaneous occlusion of an aneurysm may be induced or favored by hemodynamic vascular alterations that take place inside the aneurysm after a high-flow extra-intracranial bypass has been created.

Role of computed tomography in the management of vasospasm after subarachnoid hemorrhage.

The role of computed tomography (CT) in the management of vasospasm from subarachnoid hemorrhage was evaluated in 242 consecutive cases with CT performed within 7 days after hemorrhage. Only 20% of these cases did not show a detectable subarachnoid hemorrhage on CT. Subsequent angiograms showed vessel narrowing in 56% of the cases; associated clinical deterioration was noted in 34% of the cases. On later CT, clear ischemic areas were detected in 20% of the cases. A strict correlation between the amount of cisternal blood and the subsequent development of vasospasm was observed: although absent or thin cisternal depositions were rarely associated with vasospasm, consistent or thick depositions were frequently linked to vasospasm (72% of the cases) and to ischemic disturbances (51% of the cases), as well as to clear ischemic areas on later CT (30% of the cases). Regarding the morphology of the cisternal blood collection, the risk of developing vasospasm was at its lowest (42%) for depositions only in the frontal interhemispheric fissure and was at its highest (79%) for depositions in multiple cisterns. The site of cisternal deposition corresponded closely to the area of ischemia on later CT. The persistence of subarachnoid blood more than 72 hours after hemorrhage probably increases the risk of vasospasm, although our data are not conclusive. The definition of a CT scan "at risk" for vasospasm--based on the previous findings--gives practical advantages: proper selection of patients in regard to timing of operation, closer observation and the possibility of prophylactic treatment in patients "at risk," and more adequate evaluation of different therapeutic modalities for vasospasm. With regard to the last point, the incidence of vasospasm was not statistically different between two groups of patients uniformly "at risk": the first group submitted to early operation and the second awaiting operation.

Hemodynamic effects of preoperative embolization in cerebral arteriovenous malformations: evaluation with transcranial Doppler sonography.

A series of 83 patients with cerebral arteriovenous malformations is presented. All patients were evaluated with transcranial Doppler sonography. Thirty-two patients were treated with staged embolization and surgery: 19 of these patients were operated on within 4 weeks of the last embolization, and the remaining 13 patients underwent surgery 6 months or more from embolization. Transcranial Doppler sonography performed 1 day after embolization showed a significant (> 60%) reduction of main feeder flow velocity in 72% of patients after the first embolization and in 45% of patients after the second embolization. In no case did such a significant reduction occur after the third embolization. A flow redistribution in the basal vessels (defined as an increase in flow velocity of at least 30% of the initial value) occurred only in patients after the first embolization (64%). On delayed post-embolization studies, complete recovery of flow velocity in the embolized vessel occurred in 46% of patients, and sonographic recruitment of new feeders occurred in the remaining 54%. When main feeder flow velocity (mean) was higher than 120 cm/s after embolization and before surgery, the incidence of postoperative hyperemic complications (cerebral edema and/or intracerebral hematoma) was significantly higher than in patients with a mean flow velocity under 120 cm/s. It is concluded that transcranial Doppler sonography is a valuable method for a noninvasive hemodynamic assessment of shunt flow in arteriovenous malformations, and it permits a physiological monitoring of hemodynamic changes after embolization and allows more precise indications regarding further stages of embolization and timing of surgery after embolization.

Cerebral vasospasm after head injury.

Cerebral vasospasm occurs frequently after head injury. Correlation between neurological deterioration and vasospasm has been reported previously, but delayed neurological deterioration secondary to vasospasm in head injury is a rare occurrence. We report the case of a 57-year-old man who, after a motorcycle accident, developed an acute subdural hematoma and a thick subarachnoid deposition of blood in the left sylvian-insular cistern. After surgical evacuation of the hematoma, the patient improved until the 10th postoperative day, when he developed aphasia and a right hemiparesis. Angiography demonstrated multitapering spasm, and a computed tomographic (CT) scan showed persistence of the cisternal deposition of blood. Despite therapy with hypervolemia, the patient improved only slightly. The association of head injury with substantial subarachnoid hemorrhage producing vasospasm has been considered rarely. Delayed posttraumatic vasospasm secondary to blood degradation products seems to play some role in the vasospasm after head injury. CT scanning may be useful in predicting vasospasm in such patients, and digital subtraction angiography might be useful in demonstrating it.

Treatment of cerebral arteriovenous malformations with a combination of preoperative embolization and surgery.

Forty-nine patients with cerebral arteriovenous malformations (AVMs) were treated with preoperative embolization followed by resection using a microsurgical approach. In 27 patients, the AVM was located in an eloquent area; in 32 patients, the volume of the AVM was over 20 cm3. Preoperatively, flow-directed embolization was performed in 10 patients (28 procedures), selective embolization with threads was performed in 35 patients (46 procedures), and a combination of flow-directed and selective embolization was performed in 4 patients (12 procedures). The percentage of reduction of the AVM volume averaged 36% after embolization. Five minor complications (transient neurological deficits, in 2 cases associated with ischemic areas on the CT scan) were observed after embolization. The interval between the last embolization and surgery was as follows: within 10 days in 7 patients; between 11 and 20 days in 3 patients; between 21 and 30 days in 10 patients; between 31 and 60 days in 11 patients; and 2 months later in 18 patients. The efficacy of this combined treatment (embolization plus surgery) was evaluated by the incidence of hyperemic complications and the clinical outcome. Hyperemic complications occurred more frequently in patients with an AVM volume greater than 20 cm3. When compared with flow-directed embolization, selective embolization was linked with decreased bleeding during surgery; postoperatively, the incidence of cerebral edema was also lower. Clinical outcome was better after selective embolization, with no occurrence of major deficits and no mortality. When the percentage of reduction of the AVM volume after embolization was 40% or more, the incidence of intraoperative hyperemic complications was lower; moreover, new permanent deficits were never observed in patients with this volume reduction. A retrospective clinical comparison of two groups of patients with similar AVM volumes (greater than 20 cm3)--those given combined treatment (n = 32) versus those treated by direct surgery alone (n = 27)--showed that intraoperative bleeding appeared to decrease in patients treated by embolization; the incidence of postoperative hyperemic complications was not different in the two groups. New major deficits and deaths were less frequent in patients treated by embolization (P = 0.05 for the incidence of major deficits); postoperative epilepsy was also less common in these patients. In conclusion, combined treatment with selective preoperative embolization and direct surgery may help the neurosurgeon in the treatment of large, high-flow AVMs, reducing the risks connected with their surgical removal.

The relevance of anatomic and hemodynamic factors to a classification of cerebral arteriovenous malformations.

Potential prognostic anatomic and hemodynamic factors were evaluated in 248 patients with cerebral arteriovenous malformations (AVMs), all treated by direct microsurgical removal. The size of each AVM was calculated by its volume, obtained by the multiplication of the three AVM diameters by 0.52. A surgical classification of AVM location (in 11 groups) is proposed. Types of feeders and of drainage were classified as superficial or deep; the extent of the drainage system was classified according to a four-degree scale. The mean flow velocity in the main AVM feeder, detected using transcranial Doppler ultrasonography, was used as an indirect measure of AVM shunt flow in a small number of patients (n = 29). AVM volume was a very important prognostic factor: the incidence of hyperemic complications and the morbidity and mortality rate were significantly higher when the volume of the lesion was greater than 20 cm3 (P less than 0.0001 for hyperemic complications; P less than 0.001 for permanent morbidity and mortality). The incidence of hyperemic complications and the morbidity rate were higher in AVMs in rolandic, inferior limbic, and insular locations than in AVMs in other locations. As for other anatomic factors: a) the presence of deep feeders significantly increased the incidence of hyperemic complications, as well as the morbidity and mortality rate; b) the presence of deep drainage significantly increased permanent morbidity only; c) the extension of the venous system was significantly related to the development of hyperemic complications, and to morbidity and mortality. Transcranial Doppler examination showed that mean flow velocities greater than 120 cm/s in the main feeder were associated with a significantly higher rate of postoperative hematomas and transient deficits. A classification of cerebral AVMs that takes into account AVM volume and location, the type of feeders, the extent of the drainage system, and the main feeder flow velocity is suggested.

Surgical versus medical treatment of spontaneous posterior fossa haematomas: a cooperative study on 205 cases.

22 Italian centres have joined together in a cooperative study aiming to define the ideal management of spontaneous posterior fossa haematomas. 205 cases have been evaluated: 155 cerebellar haematomas and 50 brainstem haematomas. Out of these, 190 cases, all studied by CT scan, are the subject of the present study. Cerebellar haematomas have been divided, according to a tomographic classification, into 3 groups: group 1 (4th ventricle not shifted), group 2 (4th ventricle shifted or obliterated) and group 3 (intraventricular blood). Each group has been subdivided into: A (no hydrocephalus), and B (hydrocephalus). Regardless of therapeutical modalities, mortality rate was 38% for cerebellar haematomas; level of consciousness a few hours after haemorrhage and size of the lesion appeared to be significant prognostic factors. As a whole, medical treatment gave better results than surgical treatment. Considering each tomographical group in detail, surgery should be limited to patients in group 2B and 3B, especially when exhibiting neurological deterioration. For brainstem haematomas, overall mortality was 57%. The possibility of survival was linked to the presence or absence of initial loss of consciousness and to the size of the lesion; while hydrocephalus did not influence the final outcome, ventricular blood was a risk factor. Surgical evacuation showed some value in chronic cases. However, medical treatment appears to be the best policy for brainstem haematomas of limited size; for larger lesions, the outcome appears to be uniformly fatal, regardless of the treatment employed.

Giant unruptured aneurysm of the middle cerebral artery manifesting with epilepsy: successful surgical treatment.

A case of a giant aneurysm of the middle cerebral artery (M.C.A.), presenting with history of visual hallucinations, is described. The aneurysm was successfully excised, with disappearance of previous symptoms. The interest of the case is constituted by the very unfrequent location for an aneurysm over 3 cm in diameter, by the occurrence of epilepsy as the first symptom and by the excellent response to surgical therapy. The morphology and location of giant aneurysms, their surgical treatment and especially the problem of aneurysm-induced epilepsy are discussed.

Deep controlled hypotension with sodium nitroprusside in the surgical treatment of intracranial arterial aneurysms.

The authors report 73 cases of intracranial arterial aneurysms operated on under deep controlled hypotension--i.e. hypotension below 60 mmHg of systolic arterial pressure (s.a.p.)--. Deep hypotension was induced by Sodium Nitroprusside (SNP). No problems were encountered in order to reach or to maintain deep hypotension. SNP showed to be an easy hypotensive agent, without toxicity at the recommended dosage. Fifty-nine patients were operated on between 40 and 25 mmHg of s.a.p. In 55 patients deep hypotension lasted for 30 minutes or more, reaching 2 hours in 3 patients. Surgical results were excellent, in regard either to the control of bleeding, either to the dissection of the aneurysm. Clinical results were evaluated by comparison with 146 patients operated on under normal pressure (group of control); no complications were clearly related to deep hypotension per se. However, the authors stress the risks of deep hypotension in early surgery, due to the possible association to vascular spasm.

Patient characteristics and pre-operative therapeutic modalities.

The International Cooperative Study on the Timing of Aneurysm Surgery included 68 participating centers from 16 different countries. Eight Italian neurosurgical units participated in the Study: Bellaria Hospital, Bologna; Neurological Institute of Milan, Milan; University Hospital, Brescia; University of Milan, Milan; University of Padova, Padova; University of Rome, Rome; Civil Hospital, Verona; and Civil Hospital, Vicenza. The overall case contribution from the Italian centers was 485 cases, 14.1% of the total study population. As compared to the other centers included in the Study, the Italian centers exhibited a higher percentage of patients with impaired consciousness; a later interval of planned surgery from SAH; frequent use of preoperative lumbar drainage, as well as antihypertensives, anticonvulsants, antifibrinolytics, steroids, diuretics and LMW dextran; and less frequent use of sedatives and narcotics. The individual Italian centers differed significantly in regard to patient characteristics and preoperative therapeutic modalities. There was a relatively high number of stuporous or comatose patients admitted to Centers 1, 7 and 8, very few admitted to Centers 5 and 6, and none admitted to Center 2. The different distribution of key prognostic factors prevents a direct comparison of the overall management results of the centers. A stratification of the patients according to a risk scale and/or a prognostic model is required for comparison of the management results.

Surgical findings and postoperative therapeutic modalities.

The 8 Italian centers participating in the International Cooperative Study on Timing of Aneurysm Surgery operated upon 68% of their patients eligible for the study. This low operative rate is mainly explained by the prevailing use of a delayed surgical policy. Only 28% of cases were operated on within 3 days of hemorrhage. Although early surgery was applied in more than 50% of patients from Centers 2, 6 and 7, most other centers operated on approximately 10% of patients within this time interval. Italian centers exhibited a wide variation in planned and actual surgery interval, with only 48% of their patients eventually operated on at the planned time. Differences from planned and actual timing of surgery were less consistent in the units performing early surgery. Preoperative conditions were different between the individual centers. The percent of patients alert at the time of surgery varied from approximately 50% in Centers 3 and 7 to 90% in Center 5. Centers 2 and 6 never operated on comatose patients and rarely stuporous patients. During surgery, induced hypotension was used in 67% of Italian patients. The brain was tight at exposure in 42% of patients from Italian centers; the difference from the other study centers was very significant (p = 0.0009). Consequently major brain resection was more frequently performed in Italy than in the other centers. Brain conditions depended mainly upon timing of surgery and preoperative grade (except for comatose patients) and varied accordingly between the individual centers. Temporary arterial occlusion was rarely used in Italian centers. Intraoperative bleeding from the aneurysm was slightly more frequent than in the other centers. The overall incidence of intraoperative complications was unremarkable. There were significant differences between the Italian and the other centers regarding the use of postoperative routines and medications. In Italian centers ventricular CSF drainage, shunt insertion, ICP monitoring, sedatives and analgesics were less frequently used; lumbar CSF drainage, anticonvulsants, steroids, and diuretics were applied more frequently. In the individual centers the major differences were in the use of antihypertensives, vasopressor agents, diuretics, hypervolemia, and low-molecular weight dextran.

Results of treatment.

Overall results of management in patients admitted to the 8 Italian centers participating in the International Cooperative Study on Timing of Aneurysm Surgery were rather unsatisfactory, with good recovery in only 42% of patients, and death in 45% of patients. As compared to the other centers included in the Study, Italian centers exhibited a significantly lower recovery rate and a significantly higher mortality rate. There were significant differences also between the individual Italian centers; independently of admission neurological status and timing of surgery, the outcome was better in centers 2 and 6 (a mortality rate under 20%) and worse in centers 1 and 8 (a mortality rate around 60%). Using prognostic factor models, higher than expected mortality rates were observed in 4 centers, and lower than expected good recovery rates in 3 centers. In Italian centers vasospasm accounted for the highest morbidity and mortality rate; the difference in mortality rate from vasospasm between Italian and other centers was very significant. Other important causes of death and disability were constituted by direct effect of the initial bleed and by recurrent hemorrhage. Patients operated on in Italian centers exhibited a good recovery in 57% of cases; the mortality was 27%. Differences from the other centers were less marked than for the overall management results. Mortality rates from vasospasm and from surgical complications were significantly higher in Italian than in the other study centers. Between the individual Italian centers, vasospasm accounted for the highest mortality rate in centers 7 and 8 (17% and 28% respectively). Postoperative pneumonia was significantly more frequent in Italian than in the other centers. In regard to timing of surgery, the differences in results between Italian and other centers were less marked when surgery was performed after 10 days from hemorrhage. In Italian centers as a whole, a delayed operation was linked with a better outcome than an early or subacute operation. The lowest recovery rate was observed in drowsy patients operated on between 4 and 10 days from the hemorrhage. Focal ischemic deficits and pneumonia were prevalent after an operation within 3 days of hemorrhage, while postoperative brain swelling was most frequent in patients operated on between 4 and 10 days from hemorrhage. The differences in results between Italian and other centers and among the individual Italian centers are widely discussed; possible explanations include inadequate modalities of treatment (especially inadequate management of vasospasm) and structural deficiencies of intensive care management in seriously ill patients.

Direct microsurgical approach to aneurysms of the internal carotid bifurcation.

In this report, a series of 21 aneurysms of the internal carotid bifurcation, all treated with a direct microsurgical approach, is discussed. A classification of these aneurysms, according to angiographic and anatomical considerations, is proposed. The surgical treatment of aneurysms of the internal carotid bifurcation is discussed, emphasizing the importance of avoiding damage to perforating vessels. One of the patients presented in this report died from postoperative vascular spasm and three had transient disturbances in the postoperative course. All surviving patients recovered completely.

Microsurgical treatment of juxtapeduncular angiomas.

Five patients harboring juxtapeduncular angiomas were all treated by a direct microsurgical approach. Anatomic considerations, angiographic data on the feeding arteries, and related anomalies are discussed. The operating microscope and deep hypotension were very useful for the complete removal of these lesions, which were approached in most cases by a "backward" technique. Diffuse bleeding from the paraventricular area was difficult to handle. There were no postoperative deaths. At follow-up examination, 1 patient had hemiparesis and hemianopia, 2 patients had mild visual field defects, and 2 patients had normal neurological examinations. All but one of the patients have resumed their previous occupations. It is concluded that microsurgery constitutes the best treatment for these malformations.

Posterior inferior cerebellar artery aneurysm in the fourth ventricle: acute surgical treatment.

A case of an aneurysm of the posterior inferior cerebellar artery lying in the fourth ventricle is reported. The patient was surgically treated within a few hours after the onset of the subarachnoid hemorrhage by a microsurgical technique using direct exclusion of the aneurysm by a clip. The patient recovered completely following the operation.

Local cooling in spinal cord injury.

Eight patients with acute spinal cord injury at different levels were treated by local cooling. Early laminectomy was performed and the subdural space was irrigated with saline at 5degreesC for about two hours. In addition to this treatment, five patients, after closure of the operative wound, received local epidural cooling that was prolonged for a few days. All patients before treatment had a complete loss of function of the spinal cord below the injured segment. Four of these regained some sensory and motor functions and two were able to walk. Somatosensory cortical evoked responses were consistent with the results obtained, thus demonstrating their prognostic value. The clinical application of local spinal cord hypothermia in order to minimize the catastrophic effects of spinal cord trauma is discussed. The results obtained in these eight patients agree with the several experimental observations and seem to justify the application of this procedure to human beings.

Intracranial hematomas following aneurysmal rupture: experience with 309 cases.

Three hundred and nine consecutive cases of intracranial hematomas due to aneurysmal rupture--representing 34% of the total number of patients with aneurysms observed in a 12-year period--were evaluated; of these, 211 were submitted to computed tomography scan. Hematomas were present on admission in 71% of patients and occurred at rebleeding in 29%. Ruptured middle cerebral artery aneurysms caused an intracranial hematoma more frequently than aneurysms in other locations. Ventricular hematomas were frequently observed--especially at rebleeding--in cases with anterior communicating artery aneurysms. Basal ganglia hematomas were detected in eight cases with internal carotid bifurcation aneurysms and in three with middle cerebral artery aneurysms. Subdural hematomas were observed in 32 cases, mainly due to ruptured middle-cerebral-artery and internal-carotid-artery aneurysms. As for clinical evolution, a rapid deterioration was observed in 39% of cases and a chronic course in 46%; a subacute deterioration was far less frequent. Delayed deterioration from vasospasm was observed in 8% of cases, and appeared to be related to the amount of subarachnoid bleeding associated with the hematoma. One hundred and forty-two patients were submitted to surgical treatment (evacuation of hematoma together with exclusion of aneurysm); deep coma, poor medical condition, stabilized neurological disability, or combinations of these factors accounted for the high number of patients not operated upon. Regardless of treatment, 24% of patients showed good results and 58% died. Presence of a large hematoma, ventricular hemorrhage, and shift of the ventricles represented significant risk factors, associated with a poor prognosis. A comparison between two groups of patients admitted within 3 days of hemorrhage--47 operated on early, and 149 with delayed treatment--showed that better results were achieved by early operations, especially for cases in Hunt's grades IV and V.

[Surgical treatment of supratentorial arteriovenous malformations]. / Terapia chirurgica delle malformazioni artero-venose sopratentoriali.

The authors present their experience in the surgical treatment of supratentorial arteriovenous malformations. A few morphological data on the structure of these lesions are described, owing to their surgical relevance. The principles influencing the operative decisions--such as the age of the patient, his clinical history, the site and size of the malformation--are discussed. The operative strategy adopted for the removal of these lesions are articulated in various points: the organization for a long-lasting procedure, the use of the operative microscope and bipolar coagulation, a wide surgical exposure, a particular care for dural feeders and a wide arachnoidal opening, the trial of hypotension, the early closure of deep feeders, the saving of draining veins for as long as possible, the dissection along the sulci and into the white matter, the saving of functional arteries and accessory veins, the techniques adopted against paraventricular bleeding and hemorrhage from venous sinusoids, the coagulation of deep vessels, a particular care for possible AV fistulae under the main drainage, the "backward" technique, the "rosary-like" coagulation, a particular care for a possible division of the malformation into partitions. Particular surgical problems can occur in large AVMs, with diffuse hyperemia and hemorrhages due to anomalous perfusion of the tissue adjacent to the AVM; in these cases, controlled hypotension appears useful. The problems faced in the surgical approach to AVMs located in specific areas--such as cortical AVMs with deep extension, cortico-basal and cortico-interhemispheric AVMs, callosal AVMs, AVMs of the insula and basal ganglia, intra- and para-ventricular AVMs, juxtapeduncular and juxtasplenial AVMs--are finally discussed.

[Intracranial aneurysms and subarachnoid hemorrhage in children and adolescents]. / Aneurismi intracranici ed emorragia subaracnoidea nel bambino e nell'adolescente.

42 cases concerning symptomatic intracranial circulation aneurysms and spontaneous SAH have been observed by the authors during the period 1965-1984; 37 of them were treated from 1970 on. This group represents 2.6% in the number of patients treated for SAH during the above mentioned period in the series of Pavia and Verona Neurosurgery. In 7 cases angiography did not evidence any malformation responsible for the hemorrhage. These cases have been defined as "sine materia" SAH. In 33 cases was documented the presence of an intracranial aneurysm as responsible for the hemorrhage. In the 2 remaining cases was found an aneurysm that even if unbroken had manifested itself. In 4 cases aneurysms were mycotic ones. The most frequent sites of aneurysms have been the carotid artery bifurcation and the middle cerebral artery 24% each one followed by the anterior communicating artery 21%. 5 patients were younger than 4 years and each one had peculiar clinical features. The 37 remaining patients were older than 9 years and have been subdivided in 2 groups: 16 patients from 9 to 15 years old in who the most common site of the aneurysm was the carotid artery bifurcation and the middle cerebral artery (31%) and the frequency of intracerebral hematoma was 50%; 21 patients from 16 to 20 years old in who the most common site of the aneurysm was the anterior communicating artery (33%) and the presence of an intracerebral hematoma was markedly inferior (14%). 23 of the 35 patients having an aneurysm underwent a surgical procedure for its exclusion. Operative mortality rate was nearly 5% and morbidity rate was nearly 12%. 5 patients who were in agony when admitted were not operated; 5 patients had a conservative therapy and in 2 of them an angiography performed at distance from the hemorrhage revealed the disappearance of the aneurysm. Clinical disturbances bound to ischemic phenomenons by cerebral vasospasm were observed in only 3 patients--all of them older than 17--in who a CT scan had showed a conspicuous cisternal blood suffusion. In 13% of cases appeared hydrocephalus and only in 3 cases was necessary to perform a shunt. The global results of therapy have been significantly better than in adults having 74% of good results and 19% of deaths. This prognostic improvement is probably due both to the well known recovery from neurological failure in young patients and to the very low incidence of ischemic manifestations from vasospasm in this range of age.