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.

Effect of octreotide pretreatment on surgical outcome in acromegaly.

Pretreatment with octreotide (OCT) in acromegaly has been reported to improve surgical outcome. The objective of this study was to analyze retrospectively the effects of a 3- to 6-month presurgical treatment with OCT in acromegalics focusing on electrocardiographic (ECG) records, blood pressure levels, glucose and lipid profile, tumor size and consistency, easy tumor removal at surgery, and morphological findings at pathology. Fifty-nine patients with acromegaly who were undergoing surgical treatment were studied randomly before surgery; 37 patients were untreated, and 22 were treated with OCT at doses ranging 150-600 micrograms/day for 3-6 months. At study entry, untreated and OCT-treated patients had similar circulating GH and insulin-like growth factor I (IGF-I), glucose, and cholesterol levels as well as prevalence of overt diabetes mellitus, hypertension, and ECG abnormalities. In untreated and OCT-treated patients, respectively, radiological imaging documented microadenoma in 0 and 1, intrasellar macroadenoma in 10 and 6, intra- and suprasellar macroadenoma in 18 and 11, invasive macroadenoma in 9 and 4 patients. Before surgery, serum GH and IGF-I levels significantly decreased in the 22 OCT-treated acromegalics, and in 5 of them, a significant shrinkage was documented. ECG abnormalities disappeared in 7 of 11 (63.6%) OCT-treated patients. In 3 of the 7 patients with diabetes mellitus, treatment with OCT together with low carbohydrate intake normalized blood glucose levels, whereas in 2 patients, insulin could be replaced by oral antidiabetics, and in 2 patients, the insulin dose was reduced. Presurgical blood glucose, total cholesterol and triglyceride levels, as well as systolic (145.2 +/- 3.4 vs. 132.9 +/- 2.5 mm Hg; P < 0.01) and diastolic (94.3 +/- 1.7 vs. 84.3 +/- 1.6 mm Hg; P < 0.001) blood pressure levels were significantly higher in untreated than in OCT-treated patients. Two weeks after surgery, circulating GH and IGF-I levels were normalized in 11 untreated (29.7%) and 12 OCT-treated (54.5%) patients (P < 0.005, by chi 2 test). Macroscopically, no difference was found between untreated and OCT-treated adenomas, whereas at pathology, a significant increases in cellular atypia (31.6% vs. 19.2%; P < 0.05) was found in OCT-treated adenomas. One patients in the untreated group died from cardiorespiratory arrest during the early postoperative period. Finally, the average duration of hospitalization after operation was longer in untreated than in OCT-treated patients (8.6 +/- 0.7 vs. 5.6 +/- 0.5 days). We conclude that a 3- to 6-month treatment with OCT before surgery for GH-secreting adenoma improved clinical conditions and surgical outcome and reduced the duration of hospitalization after operation.

Osteoplastic opening of the sellar floor in transsphenoidal surgery: technical note.

The authors propose a technique of opening the sellar floor during a transsphenoidal approach by means of two small bone flaps hinged sideward. Both opening and reconstruction of the sellar floor may be improved by this method, which may be used when the floor is paper-like.

Pituitary adenoma and parasellar cysts.

Two cases of pituitary adenoma associated with a parasellar cyst are reported; only one similar case has been described previously. Even though such an association may be coincidental, a pathogenetic relationship between the two lesions in one of our cases may be assumed: shrinkage of the prolactin-secreting pituitary adenoma by means of bromocriptine therapy did, in fact, cause collapse of the cyst. Such an occurrence must not be disregarded in considering the therapeutic approach.

Reconstruction of the pituitary fossa in transsphenoidal surgery: an experience of 140 cases.

Even though the main problems of transsphenoidal surgery are encountered during the intra- and suprasellar portions of the operation, proper reconstruction of the sella turcica plays an important role in the overall results, greatly influencing the final outcome. Improper measures may bring about a complicated postoperative course, whereas a wise and precise method allows one to control any surgical condition, preventing the more dangerous consequences of the transsphenoidal approach (i.e., empty sella, cerebrospinal fluid leakage, hemorrhage, infection, etc.). The authors review the different methods of sellar plugging and, on the basis of their own experience, indicate the most suitable one for each of the more usual situations. A good result is achievable if only natural materials are used and one avoids synthetic prostheses. Extradural packing is the technique of choice whenever a hermetic closure and a particularly effective intrasellar plug are required.

Cerebrospinal rhinorrhea in a patient with a posterior cranial fossa tumor.

A rare case of a meningioma of the posterior margin of the petrous temporal bone associated with cerebrospinal fluid rhinorrhea is presented. After a careful review of the literature, the possible pathogenesis of the fistulous tract is discussed.

Subarachnoid hemorrhage and "normal pressure hydrocephalus": fatal complication of percutaneous microcompression of the gasserian ganglion. Case report.

A 62-year-old man underwent percutaneous balloon catheter compression of the gasserian ganglion for typical trigeminal neuralgia. After this, a subarachnoid hemorrhage was discovered and normal pressure hydrocephalus developed, which required shunting. Although the neurological function recovered, the patient died 8 months later because of supervening hepatic insufficiency, probably caused by protracted antibiotic therapy. Such a fatal complication, the first one associated with the technique of percutaneous trigeminal compression, was perhaps predisposed by preexistent cerebral atrophy with enlargement of the subarachnoid spaces; the unforeseen piercing of the dilated trigeminal cistern probably permitted the intracranial subarachnoid diffusion of an otherwise trivial hemorrhage. The safety of the procedure may be greatly reduced in such instances.

Instruments for endoscopic endonasal transsphenoidal surgery.

TECHNIQUE: Endoscopic transsphenoidal surgery. New, developing, minimally invasive technique. Removal of pituitary lesions and tumors of the parasellar region. TECHNICAL DEVELOPMENT: Endoscopic endonasal transsphenoidal surgery. Endonasal, not transnasal, procedure. Great respect of anatomy. Very wide surgical field, without intraoperative use of a nasal speculum, but with less room in which to work (only one nostril) and potential conflict between the surgeon's hands and the endoscope (both when entering the nostril and while working inside). INSTRUMENTATION: New instrument. Secure grip. Barycenter of the instrument is the surgeon's hands. Many different tips with different functions. Elimination of the bayonet-like shape. Handle bent in the horizontal plane to avoid interference with the surgeon's hands and to allow the distal, thin part of the instrument to be used safely and comfortably.

Ewing's sarcoma arising primarily in the spinal epidural space: fifth case report.

Ewing's sarcoma is found exceptionally as a primary epidural tumor of the spine. Four cases have been described in the literature. We describe the fifth case: a 10-year-old boy who underwent operation followed by radiotherapy and chemotherapy. For 1 year he then had a complete remission with no local recurrence and his neurological condition was satisfactory, although metastases developed later. Comparison with the cases described previously shows all five to possess interesting features in common.

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.

Forced subarachnoid air in transsphenoidal excision of pituitary tumors (pumping technique)

Inversion and prolapse into the sella of the superior capsule and the diaphragma sellae is the only condition that warrants, at least macroscopically, radical removal of tumors with suprasellar extension operated on via the transsphenoidal route. If this does not occur spontaneously, air can be introduced into the subarachnoid space through a lumbar spinal catheter to produce forced dissection of the suprasellar cisterns and collapse of the tumor capsule ("pumping technique"). This method permits complete removal of the neoplastic tissue. In a series of 124 transsphenoidal operations for tumors with suprasellar extension, spontaneous descent of the capsule occurred in only 26 cases. Forced dissection using air distension of the cisterns was carried out in 88 cases, with complete success in 56 cases, partial success in 20, and no effect in 12. There were no complications or unwanted side effects in any patient.

Luigi Rolando and his pioneering efforts to relate structure to function in the nervous system.

The fissure separating the motor from the sensory cortex and the substantia gelatinosa capping the posterior horn of the spinal cord are still known by the name of the Italian anatomist Rolando, Luigi Rolando was born in Turin, Italy, in 1773 and died in 1831. His life was not easy, the first of his problems being the death of his father when Rolando was still very young. Three people were to be influential in his life and career: Father Maffei, his maternal uncle who raised him; Dr. Cigna, the anatomy professor who discovered his talent; and Dr. Anformi, a general practitioner who introduced him to the practice of medicine and to the best circles of the city. Forced to leave Turin by the Napoleonic invasion of the country, Rolando first stopped in Florence, where he learned about anatomical dissection, drawing, and engraving and studied the appearance of nervous tissue under the microscope. Later he went to Sardinia where, although cut off from European cultural circles, he developed his major theories. Rolando pioneered the idea that brain functions could be differentiated and located in specific areas and discovered the fixed pattern of cerebral convolutions, highlighting motor and sensory gyri. He demonstrated the complexity of the central gray matter of the spinal cord, describing the "substantia gelatinosa," and he deduced that nervous structures are connected in a network of nervous fibers linked by electrical impulses. Rolando had to struggle for recognition, however, as the priority of his discoveries was challenged by the almost contemporaneous work of Gall and Spurzheim on cerebral localization and of Flourens on cerebellar function. Nevertheless, his efforts contributed greatly to the clarification of brain function. His observations on nervous anatomy have been especially accurate, as shown by the nomenclature "fissure of Rolando."

Spinal metastases with neurological manifestations. Review of 600 cases.

The authors have studied 600 cases of spinal metastasis causing a neurological syndrome. The most significant statistical data are reviewed. The cases are examined according to clinical characteristics, type of primary tumor, site of lesion, and survival. Each of these factors influenced the choice and results of treatment. As a general rule, combined treatment (surgery and radiotherapy) was used. Preliminary surgery was performed as an emergency, designed to halt progression of the neurological syndrome and to prevent its more serious manifestations. The technique and usefulness of surgery are discussed for different situations and the short-term results of treatment are related to the various factors involved.

Giant intradiploic epidermoid cysts of the skull. Report of two cases.

The authors describe two cases of giant intradiploic epidermoid cysts of the cranial vault in which there was massive intracranial extension causing signs of neurological involvement. The very slow growth and the benign histological nature of these tumors explain their long preoperative evolution and the mild neurological signs in some cases. Roentgenographic and computerized tomography findings permit a correct diagnosis. Complete removal of these cysts and their capsules can be easily accomplished, despite their large size. Total removal of these cysts is associated with a very good long-term prognosis.

Tumours of the callosal area: problems and surgical strategies.

Tumours of the callosal area are quite common. However, those primarily located in this region which remain confined within the corpus callosum area not frequent. The introduction of intraoperative location devices, coupled with preoperative MR, CT and angiography, has further enhanced the operability of lesions of the deep area around the callosal body. On the basis of their site of origin, three groups of tumours can be identified: tumours originating from the corpus callosum (defined as properly callosal); tumours secondarily invading the corpus callosum; tumours affecting the corpus callosum because of their surgical approach. Various routes have been developed to reach the callosal area, the site and direction of growth of the tumour providing indications for the preferred approach. The commonest routes are the following: interhemispheric approach; transcerebral approach; transcallosal approach; the transcallosal approach to the ventricles offers a valuable corridor in the management of intraventricular tumours. It provides a rapid and safe access, without the attendant epilepsy that often follows the transcortical approach. The neuro-psychological effect of callosotomy are minimal and not affecting the daily activities of patients. Thus it is possible to reach remote regions through a narrow entry with very low neuro-psychological impact.

Percutaneous retrogasserian glycerol rhizolysis. Observations and results about 50 cases.

Fifty patients complaining of trigeminal neuralgia have been treated by Percutaneous Retrogasserian Glycerol Rhizotomy (PRGR) from September 1983 to December 1985. In 94% of cases the procedure was successful in relieving pain with minor facial sensory loss, in 29 cases confined to the affected divisions, in 13 cases extending in an adjacent division. A herpes eruption occurred in 39 patients. A partial relapse (not requiring re-operation) verified in 12 patients. Even it firm conclusions cannot be reached as to the efficacy of this therapy, till when longer duration follow-up studies will not available, it seems to offer a manageable and very efficient way of treating trigeminal pain, constituting a valid alternative to other percutaneous techniques of trigeminal rhizolysis.

Solitary osteochondroma of the pedicle of L4 causing root compression. Case report.

Osteochondroma is about 50% of benign bone neoplasms and up to 15% of all primary tumours of the skeleton; metaphysis of long bones are more frequently involved with the spine being interested in 2.5-5% of all cases, usually pertaining to multiple osteochondromatosis, in which many areas of the skeleton are affected. A solitary osteochondroma of the right pedicle of L4 causing sciatalgic pain and difficulty warling and treated by surgery is presented. Only two other cases of solitary osteochondroma involving the lumbar spine have been previously reported.

Treatment of carotid-cavernous fistula by trans-venous anterior (trans-orbital) approach. Case report and review of previous report.

A case is reported of successful occlusion of a dural carotid-cavernous fistula (type D) by means of a transvenous anterior approach. Through the left angular vein, the distal superior ophthalmic vein (SOV) and the cavernous sinus were cannulated and three Gianturco coils were delivered close to the fistulous communications. Obliteration of the carotid-cavernous communication was achieved sparing the internal carotid artery and its branches. The major advantage of entering the sinus from the venous route is to preclude any damage to the artery, distal migration of the detachable balloon or of thrombi, intracavernous pseudoaneurysm formation. The trans-orbital approach may be considered chiefly when the openings are in the antero inferior compartment and the SOV is enlarged. Its applications, quite sporadic until now, probably will become more popular, mainly in treating D type fistulas, thanks to the good results achieved and to its safety.

Connections of sympathetic fibres inside the cavernous sinus: a microanatomical study.

A microanatomical study has been designed to investigate the pattern of arrangement of the sympathetic fibres inside the cavernous sinus. The course of these fibres has been examined in 60 fresh specimens of parasellar region from autopsy cadavers. Apart from the thin branches arising at different intervals along its course, the sympathetic plexus of the carotid artery gives rise to a large division that usually joins the abducens nerve and leaves it to combine with the ophthalmic branch of the fifth. In 10% of specimens we have found a direct connection between sympathetic fibres and the ophthalmic branch of the trigeminal nerve. We did not recognise similar connections with oculomotor and trochlear nerves.