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.

Extended endoscopic endonasal approach to the midline skull base: the evolving role of transsphenoidal surgery.

The evolution of the endoscopic endonasal transsphenoidal technique, which was initially reserved only for sellar lesions through the sphenoid sinus cavity, has lead in the last decades to a progressive possibility to access the skull base from the nose. This route allows midline access and visibility to the suprasellar, retrosellar and parasellar space while obviating brain retraction, and makes possible to treat transsphenoidally a variety of relatively small midline skull base and parasellar lesions traditionally approached transcranially. We report our current knowledge of the endoscopic anatomy of the midline skull base as seen from the endonasal perspective, in order to describe the surgical path and structures whose knowledge is useful during the operation. Besides, we describe the step-by-step surgical technique to access the different compartments, the "dangerous landmarks" to avoid in order to minimize the risks of complications and how to manage them, and our paradigm and techniques for dural and bony reconstruction. Furthermore, we report a brief description of the useful instruments and tools for the extended endoscopic approaches. Between January 2004 and April 2006 we performed 33 extended endonasal approaches for lesions arising from or involving the sellar region and the surrounding areas. The most representative pathologies of this series were the ten cranioparvngiomas, the six giant adenomas and the five meningiomas; we also used this procedure in three cases of chordomas, three of Rathke's cleft cysts and three of meningo-encephaloceles, one case of optic nerve glioma, one olfactory groove neuroendocrine tumor and one case of fibro-osseous dysplasia. Tumor removal, as assessed by post-operative MRI, revealed complete removal of the lesion in 2/6 pituitary adenomas, 7/10 craniopharyngiomas, 4/5 meningiomas, 3/3 Rathke's cleft cyst, 3/3 meningo-encephalocele. Surgical complications have been observed in 3 patients, two with a craniopharyngioma, one with a clival meningioma and one with a recurrent giant pituitary macroadenoma involving the entire left cavernous sinus, who developed a CSF leak and a second operation was necessary in order to review the cranial base reconstruction and seal the leak. One of them developed a bacterial meningitis, which resolved after a cycle of intravenous antibiotic therapy with no permanent neurological deficits. One patient with an intra-suprasellar non-functioning adenoma presented with a generalized epileptic seizure a few hours after the surgical procedure, due to the intraoperative massive CSF loss and consequent presence of intracranial air. We registered one surgical mortality. In three cases of craniopharyngioma and in one case of meningioma a new permanent diabetes insipidus was observed. One patient developed a sphenoid sinus mycosis, cured with antimycotic therapy. Epistaxis and airway difficulties were never observed. It is difficult todav to define the boundaries and the future limits of the extended approaches because the work is still in progress. Such extended endoscopic approaches, although at a first glance might be considered something that everyone can do, require an advanced and specialized training.

The endoscopic endonasal trans-sphenoidal approach to the sellar and suprasellar area. Anatomic study.

AIM: The microscopic trans-sphenoidal approach has been the treatment of choice of different sellar lesions over the last thirty years. However, due to several advantages brought by the endoscope, which provides a panoramic and close up view of all the anatomic landmarks either in the sphenoid sinus and in the sellar region, an increasing interest for the trans-sphenoidal approach to the sellar and suprasellar region is being noticed in the recent past years. Since the endoscopic approach drives the surgeon through a corridor whose walls were previously hidden by the nasal speculum, the precise knowledge of the endoscopic anatomy and the anatomical landmarks of the surgical approach are essential to better explore the mentioned advantages. METHODS: The endoscopic endonasal approach to the sellar region was performed in 40 adult fresh cadavers, with the aim of describing the anatomical landmarks for a safe realization of the surgical approach. RESULTS: The anatomic features and the variations of the sphenoid ostia, sphenoid sinus and septae, sella turcica, optic and carotid protuberances and their relationships have been described, as well as supra and parasellar neurovascular structures. CONCLUSION: The endoscopic endonasal trans-sphenoidal approach provides a straight approach to the sellar region, where it offers a multiangled and close-up view of all the relevant neurovascular structures.

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.

The extended endoscopic endonasal approach to the clivus and cranio-vertebral junction: anatomical study.

OBJECT: Lesions located in the retroclival area and at the level of the cranio-vertebral junction are typically approached through a variety of anterior, antero-lateral and postero-lateral skull-based approach, either alone or in combination. The aim of this anatomical study was to demonstrate the possibility of an endoscopic endonasal approach to the clivus and cranio-vertebral junction. MATERIALS AND METHODS: Five fresh cadaver heads injected with colored latex were used. A modified endonasal endoscopic approach was made through two nostrils in all cases. Endoscopic dissections were performed using rigid endoscopes, 4 mm in diameter, 18 cm in length, with 0 degrees lenses. RESULTS: Access to the clivus was possible using a lower trajectory when compared to that necessary for the sellar region. The sphenoid sinus is entered, and its inferior wall is completely removed, permitting the union of the sphenoidal and rhinopharyngeal parts of the clivus. The entire clivus can be removed, and the cranio-vertebral junction is opened, removing the anterior arch of atlas and the odontoid process. After the opening of the dura, the anterior surface of the pons and upper spinal cord with corresponding nerves and vasculature are visible. CONCLUSION: The endoscopic endonasal approach to the clivus and cranio-vertebral junction could be a valid alternative for surgical treatment of anterior lesions of these regions. Adequate endoscopic skill, lab training on cadavers and dedicated tools are required for clinical applications of the approach.

Clinical comparison of remifentanil-sevoflurane vs. remifentanil-propofol for endoscopic endonasal transphenoidal surgery.

BACKGROUND: Endoscopic endonasal transphenoidal surgery has been recently proposed as a minimally invasive procedure for the treatment of pituitary adenomas. The main objective of the anaesthesiologist is to induce sufficient haemodynamic control together with rapid recovery at the end of surgery. The aim of this study was to examine recovery profile, surgical operative conditions and haemodynamic differences using remifentanil infusion with either propofol target controlled infusion system or sevoflurane. METHOD: Forty-four adult patients were enrolled in a prospective, randomized, single-blind, two-group study: Group P received propofol target controlled infusion system and remifentanil; Group S received sevoflurane and remifentanil for maintenance of anaesthesia. RESULTS: No statistically significant differences between the two groups with regards to the haemodynamic changes, operative conditions as assessed by a four-step bleeding score (0-3), were obtained. Recovery times were considerably shorter after remifentanil-sevoflurane in comparison with remifentanil-propofol target controlled infusion system group (7.4 vs. 12.8 min, P < 0.01). CONCLUSION: This study demonstrates that sevoflurane-remifentanil gives a faster recovery and equivalent intraoperative status compared with propofol target controlled infusion system with remifentanil for the endoscopic endonasal transphenoidal approach.

Prognostic and survival-related factors in patients with well-differentiated oligodendrogliomas.

Oligodendrogliomas are brain tumors with unpredictable biological and clinical behavior. Prognostic factors related to survival are still controversial. The present study reviews 50 patients with well-differentiated (WHO grade II) oligodendrogliomas, located in the cerebral hemispheres and operated upon between 1980 and 1998. Prognostic factors studied include patient's age and sex, tumor location and extent, preoperative KPS, and extent of the surgical resection. The Ki-67 and the proliferative cell nuclear antigen (PCNA) levels were studied in all patients and some growth factors (GFs), including vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), platelet-derived growth factor (PDGF) and tenascine were examined in 20 patients. The long-term outcome and survival are not significantly correlated with the patient's age and sex, tumor location and extent, preoperative KPS and procedure for resection. Patients with lower Ki-67 and PCNA showed a significantly longer survival time (p < 0.001 and p < 0.019, respectively). Between 45 and 70 % of the tumors stained positive for one or more growth factors. Interestingly, cases with late recurrences (more than 4 years after surgery) and longer survival are significantly associated to negative GF expression or slight positivity, as compared with the variable and more often moderate immunoreactivity of cases with early anaplastic recurrences and shorter survival time. The presented data suggest that low proliferation indices and negative GF expression are associated with longer survival in well-differentiated oligodendrogliomas.

Microsurgical repair of the facial nerve.

OBJECTIVE: To report a series of 18 patients who underwent microsurgical repair of the facial nerve using different techniques and to discuss the indications and results of facial reinnervation procedures. METHODS: Eighteen patients with post-surgical facial palsy underwent facial reinnervation using different techniques.'These included classic hypoglossal-facial anastomosis in 13 cases, one-stage hemihypoglossal-intratemporal facial nerve anastomosis and translabyrinthine removal of residual intra-canalar acoustic schwannoma in 3, hemihypoglossal-facial nerve anastomosis in one, and neurotization of facial muscles through a nerve graft in one. RESULTS: The facial muscle function improved in all patients, up to grade III in 7 cases (39 %), grade IV in 9 (50 %) and grade V in 2 (11 %). The tongue atrophy was minimal in 70.5 %, moderate in 17.5 % and severe in 12 %. The outcome was better in younger patients (less than 40 years of age) and in those with a lesser grade of preoperative facial impairment. CONCLUSIONS: The classic hypoglossal-facial anastomosis is the technique of choice in most cases. The use of the intratemporal facial nerve is indicated when removal of an intra-canalar residual schwannoma must also be performed. The neurotization of the facial muscles through a nerve graft may be used when there is no distal trunk of the facial nerve available for the anastomosis.

Hemorrhagic vascular complications of endoscopic transsphenoidal surgery.

Two hundred and fifty consecutive patients operated on by an endoscopic endonasal transsphenoidal approach were retrospectively analyzed in order to evaluate hemorrhagic vascular complications occurring during or after the surgical procedure and their appropriate management. Vascular complications of endoscopic transsphenoidal surgery are identical to those of a microsurgical transsphenoidal approach. Damage to the sphenopalatine artery and to the internal carotid artery (ICA), which are the most frequent vascular troubles, may require technical tricks because of some aspects connected to the approach itself and of the physical properties of the endoscope. Furthermore, the progress in interventional neuroradiology in the last decades offers new solutions in respect to the past, where the use of the surgical microscope was already a tremendous progress. The anatomic substrate of each complication is discussed, along with the peculiar surgical details related to it.

Endoscopic endonasal transsphenoidal removal of an intra-suprasellar schwannoma mimicking a pituitary adenoma.

Intracranial schwannomas, accounting for 8 to 10 % of all primary brain neoplasms, are relatively frequent intracranial tumors, but a "pure" intrasellar localization is exceptional. We report the case of an intra-suprasellar schwannoma mimicking a non-functioning pituitary macroadenoma both radiographically and clinically. A 73-year-old man presented with an episode of lipothymia followed by episodes of mental confusion. The neurological investigations revealed a bitemporal hemianopia and a hypopituitaric status. The neuroradiological investigations showed an intra-suprasellar mass resembling a pituitary adenoma. The patient underwent surgery performed by means of an endoscopic endonasal transsphenoidal approach, with a subtotal excision of the tumor. The histopathological studies revealed a cellular schwannoma. The review of the literature disclosed another 8 cases of intrasellar schwannomas. The possibility of an intrasellar schwannoma has to be considered in the differential diagnoses of neoplastic and non-neoplastic lesions of the sellar area.

Primary cerebellar germinomas of the posterior fossa.

Primary cerebellar germinomas, in the absence of germ-cell tumours outside the nervous system or elsewhere in the cranial cavity and CSF pathways, are exceptional; only two previous cases have been reported in the literature. Two personal observations are described from our 20-year records of intra-axial posterior fossa tumours. The patients were a 32-year-old man and a 17-year-old woman with a clinical history of posterior fossa tumour, studied by computed tomography. The first patient with slight cerebellar signs had a small right hemispheric cerebellar tumour, and the other had a left cerebellar mass with hydrocephalus and progressive intracranial hypertension. Both were treated by tumour removal and irradiation to the whole posterior fossa. The survival times were 58 and 49 months, respectively. The diagnosis of primary cerebellar germinoma cannot be suspected before pathological confirmation. The clinical, neuroradiological and surgical findings are non-specific and quite similar to those of other malignant cerebellar tumours, such as anaplastic gliomas or metastases. Surgery and radiotherapy ensure adequate tumour control in the early stages; cases of recurrence or disseminated disease may be treated by irradiation and chemotherapy.

Dysembryogenetic spinal tumours in adults without dysraphism.

The authors report 15 patients with spinal intradural dysembryogenetic tumours with clinical onset in adult age in the absence of clinical and radiological signs of dysraphism. The series includes seven lipomas, four epidermoid cysts, three dermoid cysts and one teratoma. The tumour site was the thoracic region in three cases, the lumbar cord and conus in six, the cauda equina in four and the filum terminale in two. Among 14 patients operated upon, the surgical removal was complete in eight cases, subtotal in two and partial in four. Recurrence was noticed only in one subtotally resected thoracic epidermoid cyst. Magnetic resonance imaging allows a precise diagnosis of these lesions, mainly of small lipomas and dermoids of the conus and filum, where a tethered conus is responsible for clinical symptoms. Dysembryogenetic spinal rumours that become symptomatic in adult age may require surgical treatment. Reduction of the mass and release of any associated tethered neural elements are the goal of surgery for spinal lipomas, whereas epidermoid and dermoid cysts require a more radical treatment. However, even partial resections to avoid neural damage result in a good clinical outcome and very low risk of recurrence.

The use of a GH receptor antagonist in patients with acromegaly resistant to somatostatin analogs.

Pegvisomant, a GH receptor antagonist, is a new pharmaceutical approach to acromegaly. It enables IGF-I levels to return in the age- and sex-reference range in approximately 90% of patients. This new approach is particularly beneficial in those patients who do not experience control of hormone hypersecretion after surgery and/or medical treatment with somatostatin analogs. In our preliminary experience, out of 16 patients unsuccessfully operated on by transsphenoidal surgery and resistant to 40-mg octreotide-LAR or 120-mg lanreotide for at least 6 months, 13 normalized their IGF-I levels within 6 months from treatment beginning. Normalization of IGF-I levels was accompanied by a significant decrease of ring size. We did not observe any increase of tumor remnant in this short period of treatment. In two cases we observed a significant increase of liver transaminases levels. In conclusion, more than 80% of patients with acromegaly unsuccessfully treated by surgery or currently available somatostatin analogs can achieve normal IGF-I levels after short-term treatment with pegvisomant.

Endoscopic endonasal transsphenoidal approach: outcome analysis of 100 consecutive procedures.

The endoscopic endonasal transsphenoidal approach has been proposed in the past decade as a minimally invasive surgical technique for the removal of pituitary tumors. From January 1997 to November 1999, 100 consecutive patients with pituitary tumors underwent endoscopic endonasal surgery, according to Jho's technique. We employed 0 degrees, 30 degrees, 45 degrees, and 70 degrees rigid endoscopes, 18 - 30 cm in length, 4 mm in diameter with an outer sleeve for irrigation and secured to a holder. Among the 87 pituitary adenomas, tumor removal was total in 51, subtotal (> 80 %) in 20 and partial in 16 cases. Four craniopharyngiomas were totally removed and an intra-suprasellar arachnoid cyst was emptied; a biopsy was performed in the two patients with a clivus chordoma. The two cases of sphenoid sinusitis were cured by surgery, the three patients with spontaneous CSF rhinorrhea were successfully treated and the residual nasal meningocele was removed. The endoscopic endonasal transsphenoidal approach appeared to be less traumatic than the traditional microsurgical approach, was very effective, and was characterized by a reduced number of complications. However, the relatively small series together with the short follow-up do not allow us to draw definitive conclusions. The post-operative reduction in hospital stay (two days in 40 of 100), significantly reduced the cost of patient's management.

Endoscopic fenestration of symptomatic septum pellucidum cysts: three case reports with discussion on the approaches and technique.

OBJECTIVES: We describe three patients with symptomatic septum pellucidum cysts treated by endoscopic fenestration and discuss the different endoscopic approaches to these cysts. CLINICAL PRESENTATION: The patients are an 8-year-old boy, a 7-year-old boy and a 21-year-old woman; this last also had a right frontal cavernous angioma and a pituitary microadenoma. All patients presented with headache, associated with vomiting in two and behavioral changes in one. In all cases magnetic resonance showed a septum pellucidum cyst. INTERVENTION: Two patients were operated upon by posterior approach through a right occipital burr hole and underwent fenestration from the right occipital horn to the cyst, with a second fenestration from the cyst to the left lateral ventricle in one. Another patient underwent microsurgical removal of a right frontal cavernoma and endoscopic cyst fenestration with both lateral ventricles through a right frontal craniotomy. Postoperatively, headache and vomiting resolved in all cases and behaviour changes improved in one. CONCLUSIONS: Endoscopic fenestration is the treatment of choice for septum pellucidum cysts, where it results in immediate relief of the mass effect of the cyst and in the remission of the associated symptoms. We suggest a posterior approach through a right occipital burr hole. It allows one to easily cannulate the occipital horn, which is usually larger than the frontal one, thus avoiding the risk of damaging the vascular and neural structures surrounding the foramen of Monro. Besides, the endoscopic trajectory is in our opinion more direct. The two-window technique, with fenestration of the cyst into both lateral ventricles, improves the chances of long-term patency.

Very delayed hyponatremia after surgery and radiotherapy for a pituitary macroadenoma.

Severe hyponatremia (118 mmol/l) with natriuresis, consistent with cerebral salt wasting syndrome (CSWS), occurred 38 days after transsphenoidal surgery in a 59-year-old woman affected by a pituitary non-functioning macroadenoma. From the 35th day after surgery, she showed progressive polyuria, hypotension and hyponatremia associated with natriuresis, decreased plasma and increased urinary osmolality. The clinical examination revealed signs of dehydration and gradual decline in the level of consciousness. The anterior pituitary function was normal due to appropriate replacement of thyroid and adrenal axis. The patient was treated with saline administration until normal natremia and water balance were restored and neurological symptoms had completely disappeared. This case focuses on the unusually prolonged time of development of post-surgery hyponatremia, despite delayed symptomatic hyponatremia being reported to commonly occur 7 days after transsphenoidal surgery. Therefore, we would advise not to limit the periodic follow-up of the hydroelectrolytic balance to the first two weeks after surgery, but to prolong it until after discharge from hospital. In fact, an early diagnosis is of great importance to prevent permanent neurological damage or death. Since CSWS and syndrome of inappropriate secretion of ADH, the two disorders alternatively imputed to generate post-surgical hyponatremia, are characterized by different pathogenic mechanisms and require opposing therapeutic approaches, the occurrence of extracellular volume dilution or of increased sodium renal loss should be carefully investigated. The evidences in favor of CSWS, the possible mechanisms behind the syndrome and diagnosis and management of patients with post-transsphenoidal surgery CSWS are discussed.

Easy sellar reconstruction in endoscopic endonasal transsphenoidal surgery with polyester-silicone dural substitute and fibrin glue: technical note.

OBJECTIVE: To describe a simple method of sellar reconstruction after endoscopic endonasal transsphenoidal surgery that will allow rapid watertight closure of the sellar floor. METHODS: A bent sheet of a polyester-silicone dural substitute, fashioned for this purpose with scissors, is introduced into the sella after removal of the lesion. Because of the consistency of the sheet, it opens spontaneously and becomes stuck. Autologous fat tissue or gelatin foam is positioned thereafter, followed by another layer of the dural substitute; a film of fibrin glue completes the sealing. RESULTS: Fifteen patients underwent this method and no postoperative cerebrospinal leak or other complication was experienced. CONCLUSION: This easy method of sellar reconstruction represents an effective and fast possibility to perform the final step of the endoscopic transsphenoidal procedure, which otherwise may cause maneuverability problems in the limited space of one nostril.