Infraoptic course of the anterior cerebral artery associated with an anterior communicating artery aneurysm: anatomic case report and embryological considerations

OBJECTIVE AND IMPORTANCE: An infraoptic course of the proximal anterior cerebral artery is a rare anomaly that has been reported in 32 cases to date, often in association with cerebral aneurysms. This anomaly represents a maldevelopment in the embryogenesis of the anterior circle of Willis, resulting from the persistence of the primitive prechiasmal arterial anastomosis or an error in the development of the definitive ophthalmic artery (OphA). The case of a patient with a ruptured middle cerebral artery aneurysm and an anterior communicating artery aneurysm associated with this anomaly is described, and the anatomic features are outlined. CLINICAL PRESENTATION: A 30-year-old male patient with a right temporal hematoma and subarachnoid hemorrhage was admitted to our department 4 days after the hemorrhaging episode, with normal neurological examination results. Angiography revealed a right middle cerebral artery aneurysm and an anterior communicating artery aneurysm with an anomalous precommunicating tract. INTERVENTION: The patient was surgically treated 14 days after the hemorrhaging episode, through a right frontopterional craniotomy; both aneurysms were excluded by clipping. The anomalous infraoptic proximal tract of the anterior cerebral artery was well documented, with its origin adjacent to the OphA. The patient remained neurologically intact after surgery and was discharged 8 days later. CONCLUSION: The anomalous infraoptic course of the proximal anterior cerebral artery was associated with a low bifurcation of the ipsilateral internal carotid artery and the absence of the contralateral precommunicating tract in this patient. The strict anatomic relationship with the origin of the OphA suggests an error in the development of the definitive OphA, with persistence of an anastomotic loop between the primitive dorsal and ventral OphAs. It is concluded that, for aneurysm surgery, careful angiographic evaluation and an understanding of the neurovascular relationships in the circle of Willis are essential for a successful postoperative course, especially when very rare vascular anomalies are treated.

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.

[Cranial fractures during growth. An analysis of the authors' personal cases and therapeutic management of such childhood pathology]. / Le fratture craniche in accrescimento. Analisi della casistica personale e condotta terapeutica di tale patologia infantile.

Growing skull fractures are a rare complication of head injury with a dome fracture. The cases described in literature highlight a higher frequency of this pathology in children under than over three years of age. The authors describe 4 personal cases, underlying the clinical, diagnostic and therapeutic aspects. The aetiological hypothesis of a dural tear and its anatomic-pathological evolution are investigated. The surgical technique of dural and bony repair is also discussed. The authors conclude that this complication must be recognized early in order to obtain very good results after surgical therapy.

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.

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.

Cerebral cavernous malformations (cavernomas) in the pediatric age-group.

Cavernomas are vascular malformations composed of a compact mass of sinusoidal-type vessels that are immediately contiguous with one another and have no intervening parenchyma. Cavernous malformations were previously held to be a rare pathology occurring predominantly in adults. New neuroradiological techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) demonstrate, on the contrary, that these lesions are also more frequent during childhood than was previously thought. In our institution we observed 17 cases of cavernous malformations in patients aged between 18 months and 16 years, 16 of whom were diagnosed after 1982. In 4 of these cases there was a documented familial history; in 2 multiple malformations were present. The most common site was the subcortical frontal region, but in 1 case the malformation was located in the pineal region. The most frequent (in 12 cases) initial symptom was hemorrhage, with the characteristics of an intracerebral hematoma. In 4 cases the initial symptom consisted of epileptic fits and 2 of these patients subsequently suffered hemorrhage. In one case the symptoms observed were those of an expansile process. All our patients underwent cerebral angiography and only in 1 case did this show a vascular abnormality. CT, performed in 16 patients, gave positive results in all cases. MRI, performed in 12 patients, gave highly significant images in all cases. Radical surgical removal of the malformation was performed in 15 of the 17 patients, and the results can be considered excellent in the majority of cases. Cavernous malformations are, therefore, more frequent lesions than had previously been thought, especially in pediatric patients.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

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.

Craniocerebral epidermoids and dermoids. A review of 44 cases.

We review 40 epidermoids and 4 dermoids of the skull and brain treated surgically in our Department between 1976 and 1987. Fourteen were extradural and 30 intradural. The mean duration of symptoms was 3 years for extradural and 10 years for intradural tumours. Symptoms varied with tumour site, in some sites being helpful in differential diagnosis. Skull X-rays and CT were the key diagnostic investigations in extradural and CT in intradural lesions, the latter, with few exceptions, presenting a characteristic CT scan. In 7 cases MRI supplied important details on the tumour boundaries. All the diploic and orbital lesions were removed totally, with a good outcome. Twelve of the intradural lesions were removed totally, 9 subtotally and 9 partially, with a good outcome in 21 patients and a poor outcome in 4; 5 patients died. Outcome was unrelated to degree of removal.

Subarachnoid haemorrhage of unknown origin: clinical and tomographical aspects.

65 patients with negative but technically satisfactory 4 vessel angiography - all admitted to our Department in the years 1976-1983 - were evaluated in the present study. CT scan was undertaken in all cases (in 47 cases within 4 days of haemorrhage). Arterial hypertension was present on admission in 9% of cases. The period of follow-up ranged from 4 to 11 years, with a mean of 5.3 years. The study group was compared to a control group, comprising 760 patients with subarachnoid haemorrhage from ruptured aneurysms, admitted during the same period. Clinical grade on admission (Hunt's classification) was better in patients belonging to the study group. The amount of cisternal deposition on CT scan was less significant than in patients with ruptured aneurysms, and the deposition was often atypical (circumpeduncular, ambiental, and/or tentorial). Clinical deterioration associated with vasospasm was observed in 5% of patients in this study and in 27% of patients in the control group. In patients with a consistent or thick cisternal layer (CT scan "at risk") the incidence of clinical vasospasm was 21%, against 47% in controls. One or more rebleedings occurred in 12% of patients in the study group, against 25% of patients in the control group. A significant ventricular dilatation was observed in 15% of patients in the first group (requiring a shunt in 8%), against 25% of patients in the second group (requiring a shunt in 11%). Final outcome was favourable in 95% of patients in this study group and in 63% of patients in the control group, with a mortality rate of 5% in the first group and 32% in the second group.

Spontaneous spinal haematomas.

A series of 10 surgically treated "spontaneous" spinal haematomas (7 cases with epidural, 3 with intramedullary location), is presented. Symptomatology was rarely acute. Clinical onset was mostly dominated by spinal or radicular pain, followed by severe motor deficit. Surgical outcome was satisfactory in the majority of cases. Age, duration of symptoms, haematoma site and size appeared to have no influence on final outcome. This was significantly correlated only with the preoperative neurological condition.

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.

Rebleeding, ischaemia and hydrocephalus following anti-fibrinolytic treatment for ruptured cerebral aneurysms: a retrospective clinical study.

350 patients with subarachnoid haemorrhage from aneurysmal rupture--admitted in the years 1966-1983--were selected for a retrospective controlled study on the efficacy of antifibrinolytic therapy (AFT). Patients treated with antifibrinolytics were divided into two groups, according to the day of hospital admission and onset of therapy, respectively between 0 and 3 days (SG 1) and between 4 and 7 days from SAH (SG 2); treated patients (260 cases) received i.v. tranexamic acid (6 gr/day) for at least two weeks. Patients admitted before 1974, not receiving antifibrinolytics (90 cases), were selected as controls and divided into two groups (CG 1 and CG 2), according to the day of admission. In the first study group (admission 0-3 days) the rebleeding rate within 2 weeks was 9% versus 23% in controls (p less than 0.01). The incidence of rebleeding within 3 and 4 weeks was also significantly lower (p less than 0.05) than in controls. No significant difference was observed in the rebleeding rate in treated and untreated patients with late admission (4-7 days). Mortality from rebleeding was 16% in the first study group versus 17% in controls; in the second study group the figure was 6% versus 8% in controls. Seventy-five cases of ischaemic disorders (29%) were registered in treated patients versus 13 cases in controls (14%; p less than 0.01). Thirty-seven patients receiving AFT (14%) developed significant ventricular dilatation requiring shunt insertion, versus one patient in the control groups (1%; p less than 0.001). Final outcome was similar in the 4 groups. In conclusion--according to our data--AFT modifies the behaviour of rebleeding and the patients' course, although it does not modify the outcome after SAH. Clinical use of antifibrinolytic therapy appears still justified in those patients who cannot be operated on in the acute stage after SAH, provided that an associated anti-ischaemic therapy is undertaken.

Italian cooperative study on giant intracranial aneurysms: 1. Study design and clinical data.

10 Italian centres joined together for a retrospective Cooperative Study aimed at evaluating clinical and radiological data, various modalities of treatment and clinical outcome in patients with giant intracranial aneurysms, observed from 1976 to 1986. Various clinical data were collected through a questionnaire and evaluated through computer analysis. Two size categories were considered: 2-2.5 cm in diameter (A 1 group) and over 2.5 cm (A 2 group). A total of 240 cases were evaluated: 110 in A 1 group and 130 in A 2 group. As regards clinical history, intracranial (mainly subarachnoid) haemorrhage was observed in 70% of A 1 patients and in 45% of A 2 patients (p less than 0.001) and was more severe (Hunt's grades III-V) in A 2 patients. Symptoms of an expanding mass lesion were observed in 15% of A 1 patients and in 39% of A 2 patients (p less than 0.001). Sudden deficits of cranial nerves were observed in 11% of A 1 and 12% of A 2 patients. Ischaemic episodes were rare. On admission, Glasgow Coma Score (GCS) was 15 in 62% of cases. Regardless of treatment employed, patients in A 1 group presented a slightly better (N.S.) outcome than patients with larger aneurysms (A 2 group). The presence of intracranial haemorrhage in the clinical history increased significantly the mortality rate (p less than 0.001); symptoms of an expanding mass lesion were associated with a significant increase in the disability rate (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Italian cooperative study on giant intracranial aneurysms: 3. Modalities of treatment.

240 patients with giant aneurysms were treated in 10 Italian centres with various therapeutic modalities: out of them, 50 patients were conservatively treated (19 with a severe intracranial haemorrhage). Direct surgery was performed in 140 patients: 67% of patients with aneurysms between 2 and 2.5 cm (A 1 group) and 50% of patients with larger aneurysms (A 2 group). The aneurysm could be secured by clip in 102 cases (56% of A 1 and 31% of A 2 patients). In patients with subarachnoid haemorrhage, surgery was done within 3 days in 24 cases, between 4 and 14 days in 21 cases, and later in 52 cases. In patients operated on directly, brain swelling was observed in 39% of cases; controlled hypotension was employed in 56 cases, and temporary vessel occlusion (mainly of M 1 tract) in 33 cases; removal of intra-aneurysmal thrombi was done in 18 cases, and intraoperative aneurysmal rupture occurred in 39 cases. Carotid ligation was performed in 31 patients, and was associated with a by-pass in 17 cases. Balloon occlusion was performed in 23 cases, and was associated with a by-pass in 10 cases. As regards aneurysmal location, intracavernous aneurysms were treated mainly by balloon occlusion or carotid ligation, while carotid/ophthalmic, middle cerebral and anterior communicating aneurysms were treated prevalently by direct surgery. 60% of treated patients were submitted to postoperative angiography, and 54% to postoperative CT scan; total obliteration of the aneurysm was documented in 83% of patients submitted to postoperative angiography.

Italian cooperative study on giant intracranial aneurysms: 4. Results of treatment.

240 patients with giant aneurysms admitted to 10 Italian centres were evaluated in regard to results of treatment and postoperative complications. As a whole, a complete recovery was observed in 39% of cases, various degrees of disability in 38% of cases, and death in 23% of cases, considering also patients admitted in Glasgow Coma Scale (GCS) 3-6. By excluding patients in GCS 3-6, active treatment was linked with a recovery rate of 47% and a mortality rate of 15%; the worst outcome was observed for carotid bifurcation aneurysms, the best for intracavernous aneurysms. In patients with giant carotid/ophthalmic or supraclinoid aneurysms, the outcome was similar after early surgery and after indirect methods of treatment. Factors playing a negative influence on outcome were mainly early exclusion after hemorrhage, operative brain swelling and cisternal tamponade; induced hypotension was associated with a significant decrease in mortality. Postoperative complications were observed in 48% of cases, and were mainly caused by ischaemic disturbances not associated with vasospasm (17% of cases), followed by surgical trauma and cerebral oedema; in 32 patients the postoperative neurological deterioration was fully reversible. In patients submitted to carotid occlusion association with a by-pass did not decrease the rate of ischaemic complications. In patients submitted to active treatments (open surgery or indirect methods of exclusion) the causes of morbidity were mainly: -deficits due to mass lesion, surgical complications, and ischaemic disturbances without vasospasm; the causes of mortality were mainly surgical trauma or medical complications.

[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.

[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.