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.

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.

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.

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.

Microsurgical nervous reconstruction using autografts: a two-year follow-up

BACKGROUND

To analyze factors influencing surgical results after microsurgical reconstruction of injured nerves.

METHODS

We report a series of 32 cases of microsurgical nerve reconstruction after traumatizing lesions using nervous autografts. The series comprises 8 reconstructions of radial nerve, 8 of median nerve, 6 of ulnar, and 10 of sciatic nerve. Motor and sensitive deficits have been evaluated preoperatively using a standard grading.

RESULTS

A useful sensory recovery has been obtained in radial nerve, as well as in median and ulnar nerve reconstruction. Good results regarding the motor recovery have been obtained in superior limb nerve reconstruction. Sciatic nerve reconstruction showed the worse results.

CONCLUSIONS

There is a big discrepance between superior limb vs inferior limb results. A more than 10 cm gap has a negative influence on the progression of regenerating axons, especially in median and ulnar nerves.

[New strategies for treatment of intracranial aneurysm]

Prevision for the next future in a dramatic advances era we are living now has to be based upon fields consistently correlated to significative and immediately employable developments. Technical improvements in the next future, at the beginning of the third millennium, may schematically identified into two basic domains: the former, concerning surgical techniques; the latter, dealing with endovascular and neuroendoscopic techniques.

Neuroendoscopy. Personal experience, indications and limits

The authors report a series of 40 patients treated by endoscopic neurosurgery. It includes 31 cases of obstructive hydrocephalus, 4 paraventricular or intraventricular CSF cysts, 3 cases of multiloculated hydrocephalus, one suprasellar arachnoid cyst and one cystic astrocytoma with mural tumor nodule. Third ventriculostomy is the most frequent indication of the endoscopic neurosurgery, which is very useful also for performing fenestration of CSF cysts and multiloculated hydrocephalus. The surgical endoscopic techniques in the different above mentioned pathologies are exposed. The criteria for patient selection, the clinical results and the postoperative radiological findings, that confirm the patency of the fenestration, are discussed.

Multicentrical growth of meningiomas: "spatial" or "temporal" phenomenon

Small nodules of neoplastic cells protruding from the arachnoidal layer surrounding an intracranial meningioma, completely independent from the tumor mass, have been observed in three patients who underwent primary surgery. The high rate of recurrence for meningiomas after a seemingly total excision has been many times reported, and related to histological subtypes, tumor site, and hormonal influence. In the past meningotheliomatous cell aggregates protruding from the inner surface of the dura mater at a distance of 3 cm from the insertion of globoid meningiomas have been described, and the concept of "localized dural multifocality" emphasized. Probably this concept has to be enlarged to consider meningioma as a "neoplastic disease" with different grade of expression. The presence of unidentified macroscopic or microscopic clusters of neoplastic cells, lying around, more or less close to, the line of insertion of lesion, could render any attempt to gain a "radical" excision useless.

Percutaneous retrogasserian glycerol rhizolysis for treatment of trigeminal neuralgia. Technique and results in 191 patients

Percutaneous retrogasserian glycerol rhizolysis (PRGR) became a diffuse and valuable method for treatment of trigeminal neuralgia, following its introduction by Hakanson in 1981. Its main advantages are: a) mild postoperative facial sensory loss, b) simplification of the technique, c) reduction of costs. Our results in a series of 191 patients treated between September 1983 and September 1990 are reported. The procedure was performed according to Hakanson's method with minor modifications. In 11 cases (5.7%) we failed to pierce the foramen ovale; the procedure was successfully repeated a week or two later. In 17 cases it was impossible to obtain CSF from the needle. Complete relief of pain was achieved in 177 patients (92.7%), in 124 (64.9%) immediately, in 53 (27.8%) within 6 days; the operation was unsuccessful in 14 (7.3%). Postoperative sensory evaluation showed: no sensory loss in 33 cases (17.3%); hypalgesia in 8 (4.2%); mild hypesthesia in 88 cases (46.1%), confined to the affected divisions in 45 (23.6%), exceeding it in 43 (22.5%); moderate hypesthesia in 62 cases (32.4%), restricted to the target divisions in 36 (18.8%), exceeding them in 26 (13.6%). No case of anesthesia occurred. Complications of PRGR were: circum-oral ipsilateral herpetic eruption (herpes simplex type), spontaneously and completely regressing: 63 cases (33%); minor dysesthesia, seldom reported as painful: 33 cases (17.3%); impairment of corneal reflex: 19 cases (9.9%), the first branch being the target of the treatment in 11; regressive masticatory weakness; 11 patients (5.7%); aseptic meningitis, promptly regressed: 2 cases (1.0%). Follow-up ranges from 1 to 7 years (Sept. 1983-Sept. 1990). A recurrence was observed in 44 cases (23%): in 15 patients (7.8%) a partial relapse occurred, well controlled by drug therapy and not requiring further surgical treatment; in 29 cases (15.2%) a new percutaneous procedure was required. The mean time of recurrence was 30.5 months. The recurrence rate in the patients of our series at the end of the follow-up period was 23%. Glycerol produces a weak neurolytic lesion, that generates minor post-operative facial deafferentation; it is the best technique, in our opinion, for treatment of tic douloreux.

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.

[Complications of trans-sphenoidal surgery of the sellar lesions]

Trans-sphenoidal surgery has a very low rate of complications despite a series of apparently negative anatomo-topographical factors. Complications may be either mechanical or functional, transitory or permanent. The most important complications are: hematoma of the focus, sub-arachnoid hemorrhage, empty sella, liquoral fistula, opto-chiasmatic lesions, arterial lesions, lesions of the cavernous sinus, parenchymal damage, nasal and paranasal mechanical lesions, insipid diabetes, hypopituitarism. The overall mortality rate is 0.4-1% and is always associated with predisposing factors, such as previous treatment, voluminous extrasellar growth, concomitant causes of disease; the most frequent causes of death are: hemorrhagic phenomena in the extrasellar portion of large size adenomas; vascular lesions involving the intracavernous carotid artery; and hypothalamic lesions. The frequency of major complications is in the region of 2.3%. Predisposing factors are: volume, consistency, invasiveness, previous treatment, intratumoral necrotic-hemorrhagic phenomena, age. Surgery is only indicated for some of the above complications, including hematoma of the focus, acute postoperative empty sella, rhinoliquorrhea resistent to conservative treatment, excessive filling of the sellar cavity. All the other possible complications are results or functional alterations which must be treated medically, even if a specific therapy only exists for some (such as early hypotonic polyuria). The series of patients reported here refers to the period 1978-1989 and accounts for a total of 259 trans-sphenoidal operations performed in 245 patients. Of the secondary operations, 6 were due to postoperative complications (hematoma of the focus in 2 cases, rhinoliquorrhea in 2 cases; empty sella and hemorrhagic infarction of a large suprasellar site in the 2 remaining cases). There were 2 deaths related to direct mechanical complications (both caused by hemorrhagic infarction of large tumoural residues and the surrounding cerebral parenchyma). Complications which did not require re-operating were observed in 11 further cases: 6 cases of persistent rhinoliquorrhea which required protracted spinal drainage; 2 cases of deterioration of previous visual deficits unrelated to either hematoma of the focus or empty sella but caused by trauma to optic structures, either directly or on a vascular basis; 3 cases of dyplopia due to oculomotory deficiency. In terms of hypophyseal function, the ex-novo onset of postoperative pan-hypopituitarism and insipid diabetes was only observed in one case.(ABSTRACT TRUNCATED AT 400 WORDS)

Management of primary or recurring grossly cystic craniopharyngiomas by means of draining systems. Topic review and 6 case reports

In primary or relapsing grossly cystic craniopharyngiomas most of the problems related to the neoplastic mass may be, even if temporarily, improved by reducing volume of the cyst. A major surgical approach is unjustified when the aim is only to empty the cyst contents. Drainage of the cyst cavity by means of derivative techniques may be as effective and less invasive; in combined management plans that such tumours often require, they are, therefore, useful complementary procedures that can achieve long-lasting relief of symptoms, provided that the cyst is unilocular. Technical features and indications for such methods, with special regard to the techniques of sump drainage and of tube ventriculocystostomy, are discussed on the basis of the few reported series and of 6 personal cases. Usually only palliative aims are achieved, waiting for more definitive treatment; in a few selected cases, however, they may be quite effective.

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.

Paramedian hourglass epidermoid cysts extending in the middle and posterior cranial fossa

Four cases of large paramedian hourglass epidermoid tumors extending both in the middle and posterior cranial fossa are reported and other 16 cases from the literature are reviewed. The length of the clinical history and the triviality of neurological symptoms in spite of the size of the tumor are emphasized. CT scanning well documents the extension of these epidermoids and usually consents to differentiate them from the arachnoid cysts. The subtemporal transtentorial approach is more advisable, although a two-stage operation by subtemporal and suboccipital route can be necessary in some cases. Nevertheless the difficulties and the risk of the surgical treatment make very hard the complete removal of the tumor in most cases.

Subarachnoid hemorrhage due to a spinal neurinoma

A rare observation of spinal neurinoma associated with subarachnoid hemorrhage is reported and the other 12 cases in the literature are reviewed. The extramedullary location of the tumor and the feeble arachnoidal attachments to the spinal cord favor subarachnoidal bleeding in these cases. When the meningeal signs are evident and signs of spinal cord impairment are still unclear, an intracranial origin of the bleeding must be excluded. In doubtful cases, selective spinal angiography is useful in the differential diagnosis between a bleeding spinal tumor and an arteriovenous malformation of the spinal cord.

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.

Some technical modifications of surgical treatment of lumbar disc lesions

The author's experience in the surgical treatment of lumbar disc lesions is reported. The following technical devices have been adopted: -- curved unilateral incision into deep fascia --interlaminar space widening by chisels and gouges, avoiding the use of rongeurs -- sodium succinate methylprednisolone injection into dural sac. -- early ambulation (within the first 18 hours). Benefits obtained by these procedures are: -- earlier disappearance of pain -- remarkable reduction of stay in hospital -- earlier and more complete recovery.

Peripheral influences on VPM-VPL thalamic nuclei in the human. A study on evoked potentials

Thalamic evoked potential (TEP) was recorded in VPM-VPL nuclei following ulnar and sciatic stimulation in humans. The latencies of the early positive deflection were found respectively at 9.6±1.5 and 21.2±3.1 msec for stimulation at the elbow and at the popliteal fossa. It was proved that TEP is not produced by muscular activity and is unaffected by attention or distraction. Stimulation of low threshold afferent fibers of the ulnar nerve was followed by TEP, even in the absence of EMG responses. Their nature is discussed. No clear evidence was found that group I afferent fibers of the sciatic nerve project to the thalamus. Group II cutaneous fibers project to the thalamus also through a fast route; late components of TEP (40–45 msec for the ulnar nerve stimulation) are assigned to group III excitation.