Reconstruction of artery wall in experimental giant aneurysms.

AIM: This study describes five experimental techniques for the surgical treatment of giant aneurysms based on the resection of the aneurysm sac and reconstruction of the arterial wall. METHODS: The aneurysm was realized with a venous graft implanted with end-to-side anastomosis on the common carotid artery on 50 rabbits (with each technique realized in 10 rabbits). The first two experimental techniques (A and B) involve the reconstruction of the artery wall by a synthetic dural patch and by direct suture reinforced by a venous patch, respectively. In the model C a collateral branch arising from the aneurysm is resected and reimplanted on the parent artery after aneurysm resection. In the experimental model D the arterial defect is closed by a venous patch surrounding the whole arterial wall and sutured with the aid of fibrin glue. In the model E clamping of the parent artery proximal to the aneurysm site and termino-lateral anastomosis with the contralateral artery lead to the thrombosis of the aneurysm fulled only by refluent flow. RESULTS AND CONCLUSION: The venous pouch experimental models are useful to realize giant aneurysms. The above described techniques allow to realize the reconstruction of the arterial wall without stenosis and shortening the clamping time.

Intracranial hypertension due to meningioma of the unique transverse sinus.

We describe a 28-year-old woman with intracranial hypertension due to a meningioma invading the unique transverse sinus (with absent contralateral sinus). Clinical remission and normalization of orbital echography were obtained by resection of the intradural tumor and peeling of the dural attachment. In such cases, resection and reconstruction of the involved sinus segment is at high risk of venous infarction. Endovascular stenting of the obstructed sinus is a valid alternative when the stenosis is not remarkable. Single tumor removal may lead to partial sinus decompression and increased venous flow, resulting in long-term clinical remission.

Paravertebral high cervical chordoma. A case report.

Spinal chordomas are more often located on the midline and are associated with marked destruction of the vertebral bodies. We report a rare case of large cervical (C2-C3) right lateral paravertebral chordoma extending into the spinal canal through a very enlarged intervertebral foramen. The tumor was initially diagnosed as a mucous adenocarcinoma on a percutaneous needle biopsy. However, the neuroradiological features, including the well-defined tumor margins, the regular and sclerosing lytic bone changes with regular enlargement of the intervertebral C2-C3 foramen, were in favor of a more slowly growing lesion, such as schwannoma or neurofibroma. At surgery a well-demarcated capsulated tumor involving the nerve root was partially resected. Histology was in favor of a low-grade chordoma (Ki-67/MIB-1<1%). Postoperative proton beam therapy was also performed. The differential neuroradiological diagnosis is discussed.

Spontaneous resolution of Chiari type 1 malformation. A case report and literature review.

We describe a 62-year-old woman who presented with a history of ataxia, dizziness and urinary urgency. Neurological examination disclosed a positive Romberg sign, ataxia and postural instability. A magnetic resonance imaging (MRI) scan showed Chiari type 1 malformation (CM1). Forty-eight months later, the patient was clinically improved and underwent a second MRI examination, which showed complete resolution of the Chiari 1 malformation. Spontaneous resolution of CM1 is exceptionally rare and has to be considered in the radiological and clinical management.

Classical pterional compared to the extended skull base approach for the removal of clinoidal meningiomas.

We reviewed a series of 46 consecutive, surgically treated patients with clinoidal meningioma to compare the classical pterional approach (32 patients) to an extended approach including extradural clinoidectomy and removal of the optic canal roof (14 patients). The tumor size and Al-Mefty type, the extension into the optic canal, the time to identification of the optic nerve and internal carotid artery, and the visual outcome were evaluated. Complete tumor resection was obtained in 81% of patients with the classic pterional approach compared to 93% of patients using an extended approach. The extended skull base approach should be used routinely in clinoidal meningiomas >2.5 cm in size, in ones of Al-Mefty type III, and in all patients with tumor extension into the optic canal.

Intracranial dural metastasis from uterine leiomyosarcoma with orbital extension.

Intracranial metastases from uterine leiomyosarcoma are very rare and have been found mainly in the brain (17 cases); on the other hand, metastases to the skull, dura and orbit are really exceptional. The authors report the case of a 57-year-old woman who presented with a 6-week history of right proptosis, left hemiparesis, intracranial hypertension and torpor 8 months after surgery for uterine leiomyosarcoma. CT scan showed a very large right frontal tumor with both intracranial and intraorbital extension. At operation the tumor was found to arise from the dura of the right anterior cranial fossa; complete removal of the intracranial tumor mass and partial removal of the intraorbital component were performed. However, early tumor regrowth was observed 45 days after operation and death occurred 2 months later. Pathologic examination showed a high-grade sarcoma with smooth muscle differentiation and high mitotic activity. Immunohistochemical staining revealed positivity for actin and vimentin and negativity for S-100 protein, cytocheratin and desmin. This is the first reported case of uterine leiomyosarcoma metastatic to the dura of the anterior cranial fossa with intracranial and intraorbital extension. An aggressive surgical resection is the best treatment of intracranial metastatic leiomyosarcoma, because of the scarce response to radiotherapy and chemotherapy. However, the outcome is poor, with early recurrence.

Symptomatic spinal cord metastasis from cerebral oligodendroglioma.

Spinal subarachnoid spread is not uncommon in brain oligodendrogliomas; on the other hand, symptomatic involvement of the spinal cord and cauda is very rare, with only 16 reported cases. We report the case of a 41-year-old man who underwent resection of a low-grade frontal oligodendroglioma 4 years previously. He was again observed because of bilateral sciatic pain followed by left leg paresis. A spine MRI showed an intramedullary T12-L1 tumor with root enhancement. At operation, an intramedullary anaplastic oligodendroglioma with left exophytic component was found and partially resected. Two weeks later, a large left frontoparietal anaplastic oligodendroglioma was diagnosed and completely resected. The patient was neurologically stable for 8 months and died 1 year after the spinal surgery because of diffuse brain and spinal leptomeningeal spread. The review of the reported cases shows that spinal symptomatic metastases can occur in both low-grade and anaplastic oligodendrogliomas, even many years after surgery of the primary tumor; however, they exceptionally occur as first clinical manifestation or as anaplastic progression. The spinal seeding represents a negative event leading to a short survival.

MRI features of spinal solitary fibrous tumors. A report of two cases and literature review.

Spinal solitary fibrous tumors (SFT) are very rare neoplasms occurring in the spinal canal, with only 38 cases reported in ten years since the first description. We describe two cases of SFT of the spine and review 33 well-documented cases in the literature to define distinctive radiological and surgical features raising the suspicion of a spinal SFT before histological verification. A 67-year-old man with cervical myeloradiculopathy had a large extramedullary tumor of the cervical spinal canal extending from C4 to C7. On MRI the tumor was isointense on T1-sequences and hypointense on T2-sequences, and had marked contrast enhancement. At surgery, the tumor was intradural extramedullary, with no dural or root attachment, but it was adherent to the cord. Complete tumor removal was achieved with good outcome. A 75-year-old man with progressive thoracic myelopathy had an intramedullary tumor at C6 and C7 level, which was hypointense on T1- and T2-weighted images of MRI. At surgery, the tumor was intramedullary and strongly adherent to the cord; it was successfully removed. Both tumors were composed of elongated cells with a collagen-matrix background. Immunohistochemical staining was positive for vimentin, CD34, and bcl-2, and negative for EMA and S-100 protein. A careful analysis of our own and the other reported cases of spinal SFTs may disclose some peculiar features of this rare tumor. A spinal intramedullary or extramedullary tumor, hypointense on T2-weighted images of MRI, which intraoperatively shows hard consistency, scarce vascularization, no nerve root involvement, no or weak dural attachment, absence of arachnoidal interface, and adherence to the spinal cord may suggest the diagnosis of SFT.

Endovascular treatment of a giant dissecting aneurysm of the posterior cerebral artery. A case report and literature review.

We describe the case of a 60-year-old man who presented with a giant dissecting aneurysm of the left P2 segment. Intracranial dissecting aneurysms often occur in the vertebrobasilar system, but rarely involve the posterior cerebral artery (PCA). PCA aneurysms tend to have some peculiar features and therefore may be considered a separate entity, even from the vertebrobasilar aneurysms. The patient was treated by endovascular occlusion of both parent vessel and the aneurysm, and he tolerated the procedure well with a complete resolution of clinical deficit, following volume reduction of the aneurysm. This paper presents additional evidence to literature reports suggesting that endovascular parent artery occlusion with coils is an effective and well-tolerated treatment for distal PCA aneurysms. Our review contributes to collect data regarding the incidence of recurrence as a measure of long-term efficacy of this therapeutic approach.

Spinal meningiomas: age-related features.

OBJECTIVES: Spinal meningiomas mainly occur in old patients, with a remarkable female prevalence. This study investigates the different features between younger and older patients in an adult population (>18 years). MATERIALS AND METHODS: A surgical series of 120 adult patients operated on for spinal meningiomas at the Neurosurgical Clinic of the "Federico II" University of Naples is reviewed. In this series 117 patients with a sporadic spinal meningioma were divided in two groups: group I including 30 patients (25.6%) younger than 50 years of age, group II including 87 patients (74.4%) older than 50 years. 3 patients had a spinal meningioma and neurofibromatosis. Several parameters, including sex, predisposing factors, tumor location and growth, histology, recurrences, proliferation index Ki-67 LI, and outcome, are considered and compared in the two age groups. RESULTS: Group I showed an incidence of high cervical spine (C1-C4) meningiomas higher than group II (23.3% vs 3.4%, p=0.026) and lower rate of thoracic tumors (60% vs 82.7%, p=0.04). No significant differences of histological type and Ki-67 LI were found. Group I had 2 cases of atypical meningiomas (6.6% vs 0%, ns). Recurrences occurred in 6.6% of group I and 2.6% of group II, with no significance. In recurrent meningiomas values of Ki-67 LI were significantly higher than values in not recurrent meningiomas (p=0.0001), whereas no difference of estrogen and progesterone receptor expression was noted. CONCLUSIONS: Younger adult patients with spinal meningiomas show not rare occurrence of NF (9%) and significantly higher incidence of high cervical and lower incidence of thoracic localizations with respect to the older patients. On the other hand, there are not significant differences of histology, Ki-67 LI and recurrence rate, excepting for a slight difference for atypical meningiomas.

Fusiform aneurysm of the proximal anterior cerebral artery (A1).

OBJECTIVE: Fusiform aneurysms of the A1 segment of the anterior cerebral artery (ACA) are exceptional, with only 15 reported cases. This article presents an additional case treated by microsurgical trapping. The aim is to discuss the treatment of these aneurysms based on the aneurysm morphology and the anatomy of the ACA complex. CASE REPORT: A 52-year-old woman with subarachnoid hemorrhage (Hunt-Hess grade II) showed an aneurysm of the proximal part of the A1 segment of the left ACA involving the whole circumference of the arterial wall on computerized tomography angiography and digital angiography. There was good collateral blood flow from the right ACA to the distal left ACA. A left pterional craniotomy allowed us to expose a large aneurysm of the proximal part of the A1 segment; the artery entered into the aneurysm sac and could not be identified at the level of the aneurysm. Trapping of the aneurysm was performed with a distal clip placed just before the origin of the artery of Heubner. No neurological deficits were observed postoperatively. CONCLUSION: Clipping of fusiform aneurysms of the A1 segment using an encircling clip is the treatment of choice but, more often, this is impossible. Trapping of the aneurysm with preservation of the perforating branches (mainly the Heubner artery) may be easily performed when collateral blood flow from the contralateral ACA is sufficient.

Expression of growth factors in brain tumors: correlation with tumor grade, recurrence and survival.

OBJECTIVE: The aim of this study is to evaluate the correlation between the expression of some growth factors (GFs) and the tumor grade, recurrence and survival of brain glial and ependymal tumors. MATERIAL AND METHODS: The expression of vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR), tenascine, transforming growth factor (TGFbeta), isomeres, platelet-derived growth factor (PDGF) and p53 was studied in 40 primary brain tumors, both low-grade and high-grade, including astrocytomas, oligodendrogliomas, glioblastomas and ependymomas. The same GFs were also studied in 46 specimens of recurrent tumors from the same patients. The positivity and intensity of the immunohistochemical expression were correlated with the tumor grade, the interval and type of recurrence, and the survival. RESULTS: The expression of all GFs, excepting TGFbeta1, TGFbetaRI and tenascine, was found to be correlated with the tumor grade in all tumors of both astroglial and oligodendroglial origin, whereas ependymomas showed significant differences only for EGFR. Low-grade (Grade II) tumors recurring as anaplastic (Grade III) forms showed GF expression rather similar to initially high-grade gliomas and significantly higher than that of low-grade (Grade II) tumors in both initial surgery and recurrence. Besides, low-grade (Grade II) tumors recurring as low-grade showed significantly longer median recurrence time (5.4 vs. 3.5 years) and better median survival (8.3 vs. 5.4 years) than those recurring as anaplastic forms (WHO III). CONCLUSION: The immunohistochemical study of expression of VEGF, EGFR, TGFbeta2, TGFbeta3, PDGF and p53 in all low-grade (Grade II) brain gliomas at the first operation may help to differentiate cases with slower evolution and longer survival from those with higher potential of anaplastic transformation.

Intracranial extension of salivary gland tumors.

OBJECTIVE: The aim of this report is to describe 3 cases of salivary gland tumors with intracranial extension associated to an extracerebral mass lesion, and to discuss the frequence, pathology and treatment of these very rare localizations. CLINICAL MATERIAL: The 3 patients were 1 woman and 2 men, aged 44, 53 and 74 years, respectively. The primary tumors were an adenocarcinoma and a malignant oncocytoma of the parotid gland and an adenoid cystic carcinoma of the submandibular gland. The location of the intradural extra-axial tumor was the middle fossa and temporal region in 2 cases and the cerebellopontine angle in 1. Surgical treatment consisted in the seemingly complete removal of 2 tumors with middle fossa localization and partial removal of the cerebellopontine angle lesion. Radiotherapy was administered in all 3 cases and chemotherapy in 2. RESULTS: 1 patient is alive and free of recurrence 32 months after removal of the intracranial tumor; 2 other patients died 28 months and 12 months postoperatively. CONCLUSIONS: The intracranial extension of salivary gland tumors is a very rare event. An aggressive surgical resection followed by radiotherapy is justified in cases with significant intracranial mass lesions and scarce bone and dural involvement.

Early clinical and neuroradiological worsening after radiotherapy and concomitant temozolomide in patients with glioblastoma: tumour progression or radionecrosis?

OBJECTIVES: This study investigates the diagnosis and management of patients with resected brain glioblastomas who presented early clinical and neuroradiological worsening after the completion of the Stupp protocol. Its aim is to discuss the occurrence of early radionecrosis. METHODS: Fifty patients with brain glioblastoma treated by surgical resection and Stupp protocol were reviewed; 15 among them (30%) had early clinical and neuroradiological worsening at the 6-month follow-up. The MR spectroscopy and surgical findings of these patients are reviewed. RESULTS: MR spectroscopy was in favour of tumour recurrence in 14 among 15 patients and showed radionecrosis in one. Among 10 patients who were reoperated on, 7 had histologically verified tumour recurrence or regrowth, whereas in 3 histopathology showed necrosis without evidence of tumour. The 7 patients with tumour progression had prevalence of focal neuroradiological signs (6/7) and a survival of 7.5-12 months (median survival 10 months). The 4 patients with early radionecrosis (including one patient who was not reoperated on) had clinical worsening with mental deterioration, confusion and ataxia, and MR spectroscopy positive for tumour recurrence in 3. Three were alive 24-30 months after the end of the radiotherapy, whereas one died at 40 months. CONCLUSION: Early radionecrosis after the Stupp protocol is not a rare event due to the radiosensitization effect of temozolomide. This phenomenon may predict a durable response to radiotherapy. MR spectroscopy may simulate tumour recurrence. A correct diagnosis is necessary to avoid useless reoperations and incorrect withdrawal of temozolomide.

Spheno-orbital meningiomas: surgical approaches and outcome according to the intraorbital tumor extent.

OBJECT: This study proposes a topographical classification of spheno-orbital meningiomas. Its aim was to define whether the different intraorbital localizations require different surgical approaches and have different recurrence rates and outcomes. MATERIAL AND METHODS: Sixty patients with spheno-orbital meningiomas operated upon between 1983 and 2003 were reviewed. Four types were identified according to the extent of intraorbital tumor invasion: I: lateral or superolateral (15 cases); II: medial and inferomedial (8 cases); III: orbital apex (25 cases); IV: diffuse (12 cases). Three surgical approaches were used: lateral orbitotomy (15 cases with lateral or superolateral tumors), supraorbital-pterional approach (42 cases, including all 8 inferomedial cases, all 25 orbital apex cases, and 9 of 12 diffuse tumors), and a fronto-temporal-orbitozygomatic approach (only 3 cases with diffuse meningiomas and large-scale tumor invasion in the infratemporal fossa and cavernous sinus). RESULTS: Tumor removal was complete (Simpson grades I and II) in 40 cases, and incomplete in 20 (33.3%). There were two postoperative deaths (3.3%). A sufficient clinical follow-up was obtained in 52 cases. The clinical outcome was excellent in 26 patients (50%), good in 16 (30.8%), moderate in 6 (11.5%), and poor in 4 (7.7%). Twenty-two of 52 patients (42.3%) had tumor recurrence; however, 44 (84.6%) achieved tumor control after surgery alone through two or more operations. The recurrence rate was correlated with the Simpson grade of resection and the intraorbital tumor location. Significantly higher rates of recurrence were recorded for the orbital apex type (50%) and diffuse forms (60%), than for the inferomedial (28.5%) and superolateral forms (23%). CONCLUSIONS: Spheno-orbital meningiomas may be classified according to the location and extent of the intraorbital tumor invasion. The different localizations may require different surgical approaches, with different chances of complete removal. The location and extent of the intraorbital tumor results in different recurrence rates, lower for superolateral and inferomedial forms than for orbital apex and diffuse forms.

Local versus diffuse recurrences of meningiomas: factors correlated to the extent of the recurrence.

OBJECTIVE: The aim of this study is to evaluate the factors correlated with the different patterns (local, peripheral and diffuse) of meningioma recurrence. MATERIAL AND METHODS: 55 patients with benign (WHO I) meningiomas which recurred after seemingly complete removal were reviewed; 40 (Group I) had local or peripheral recurrences (< 3 cm from the initial dural attachment) and 15 (Group II) had distant and diffuse recurrences. Patient age and sex, tumor location, interval of recurrence, tumor shape, type of brain-tumor interface, histological subtype, mitotic index (MI) and progesterone receptor (PR) expression of the initial tumor, histological WHO Grade of the recurrent tumor and patient outcome were analyzed and correlated with the pattern of recurrence. RESULTS: Flat-shaped meningiomas with large dural attachment showed a significantly higher rate of diffuse recurrences than round tumors, whereas the brain-tumor interface and the tumor location were not relevant (excepting the lack of convexity meningiomas in the group of diffuse tumors). There were no significant differences of histology, MI and PR expression of the initial tumor and histological grade of the recurrent tumor between the two groups. CONCLUSIONS: The different patterns of meningioma recurrences (local, peripheral, diffuse) are not correlated with the tumor location and histology and do not represent a different biological tumor progression. We agree that most unexpected extensive recurrences result from a more extensive microscopic dural involvement.

Long-term outcome of endoscopic third ventriculostomy in obstructive hydrocephalus.

This multicentric study reports on 140 patients who underwent endoscopic third ventriculostomy for obstructive hydrocephalus in four Italian neurosurgical centers between 1994 and 1999. Its aim is to define the long-term outcome of these patients many years (6-12) after the initial procedure. The study includes both children and adults; the etiology of the hydrocephalus was malformative aqueductal stenosis in 88 cases (62.8%), compression by tumors of the mesencephalic and pineal regions and posterior fossa in 45 (32.2%) and post-infection aqueductal stenosis in 7 (5%). The ETV was performed by using the standard technique. The overall rate of good results (shunt-independent patients with clinical remission or improvement) was 87.1%. Eighteen patients (12.9%) required a shunt because of ETV failure. The long-term outcome of ETV in this study was not influenced by the patient's age and the etiology of the hydrocephalus (although cases secondary to cisternal hemorrhage and infections are not included). Other series including cases with long follow-up are analyzed. In conclusion, ETV results in a high rate of good long-term outcome in patients with obstructive hydrocephalus. Because postoperative failures occur early, clinical and radiological control studies must be performed particularly in the first years after the neuroendoscopic procedure.

Suprasellar arachnoid cysts: endoscopy versus microsurgical cyst excision and shunting.

The aim of this study is to define the indications to endoscopy versus other surgical procedures in the management of suprasellar arachnoid cysts from a personal series and an extensive literature review. Five symptomatic patients (two children and three adults) with suprasellar arachnoid cysts were treated by endoscopic fenestration in our neurosurgical unit. The endoscopic procedure consisted of ventricle-cyst-cisternostomy in three cases and ventricle-cystostomy in two. Four patients were cured after the endoscopic procedure alone, whereas another with rhinoliquorrhoea later required a craniotomy. The literature review includes 102 patients treated by endoscopic fenestration and 74 treated by other procedures, including microsurgical cyst resection through craniotomy (38 cases), shunt of the cyst (21 cases) and percutaneous ventricle-cystostomy (15 cases). Among the reviewed cases, the rate of cure or improvement was 90% (92 among 102 cases including ours) after endoscopy and 81% (60 among 74 cases) after other surgical procedures. The results of this study suggest that endoscopic ventricle-cyst cisternostomy is the best treatment for suprasellar arachnoid cysts, because it is less invasive, provides the best results and avoids shunt dependency in most cases.

Is endoscopic third ventriculostomy an internal shunt alone?

OBJECTS: This study was made to define the mechanism of endoscopic third ventriculostomy (ETV) in the various forms of hydrocephalus. METHODS: One hundred and forty patients with various forms of hydrocephalus treated by ETV are reviewed. The series includes 75 cases (53.5%) of triventricular obstructive hydrocephalus (group 1), 20 (14.3%) with hydrocephalus following CSF infection or hemorrhage (group 2) and 45 (32.3%) with idiopathic normal pressure hydrocephalus (group 3). Factors which have been considered include type and etiology of the hydrocephalus, intraoperative evidence of downward and upward movement of the third ventricular floor after the stomy, patient outcome and rate of shunt-independent cases. RESULTS: The overall rate of successful ETV was 79.3% (111/140 shunt-free patients). The success rate was 88% (66/75) in group 1, 60% (12/20) in group 2 and 73.4% (33/45) in group 3. The intraoperative finding of significant movement of the third ventricular floor after the stomy was evidenced in 121/140 cases (86.4%) and particularly in all cases of group 1, in 9/20 (45%) of group 2 and in 37/45 (82%) of group 3. CONCLUSIONS: The relatively high rate of success of ETV in various forms of hydrocephalus and the intraoperative finding of mobility of the third ventricle floor after the stomy suggest that the first mechanism of the ETV is the restoration of pulsatility of the ventricular walls. This results in restoration of the CSF flow from the ventricular system into the subarachnoid spaces and normalization of the CSF dynamics. Accordingly, ETV is not only an internal shunt, but it primarily influences the capacity of the brain pulsatility to ensure CSF flow.