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At least 145 records · Page 8Linked to original sources
PubMed2004

[Post-processing of radiological data for preoperative planning in skull base surgery].

Preoperative planning in skull base surgery is usually based on numbers of different radiological data. To use this complex data digital post-processing is necessary. There is a significant difference between radiological and surgical post-processing. Planning the approach, resection of the tumour and reconstruction of the defect are supported by the software demonstrated in this study. Integration of the results in a closed workflow of Information-Guided Therapy will increase the potentials of surgical post-processing in the future (i. e. intraoperative navigation and visualization). Evidence based medicine will use digital data of surgical planning.

Carcinoma, Adenoid Cystic↗
PubMed2006

Revision lateral skull base surgery.

OBJECTIVE: To describe functional and reconstructive results after revision lateral skull base surgery with comparison of benign and malignant lesions. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: All patients undergoing revision surgery for benign and malignant lateral skull base tumors. INTERVENTIONS: Surgical resection of recurrent lateral skull base tumors and reconstruction of resulting defects. MAIN OUTCOME MEASURES: Cranial nerve function postoperative complications. RESULTS: Forty operations for recurrent lateral skull base tumors occurred between January 1, 1987, and December 31, 2003, with follow-up of at least 1 year. Thirty-three operations were for benign lesions, 27 of which were glomus tumors. Seven operations were for malignant tumors. Fifty-eight percent of patients had preoperative cranial nerve deficits (66% of benign tumors and 14% of malignancies). The most common preoperative deficit occurred in the Xth cranial nerve. Postoperative cranial nerve deficits were seen in 95% of patients and multiple nerve deficits were seen in 75%. The most common postoperative deficits were observed in the IXth and Xth cranial nerves. Thirty-one patients had one previous procedure, six had two previous procedures, and three had three previous procedures. Abdominal fat and temporoparietal fascia were the most common reconstruction materials. There was one case of meningitis, two cerebrospinal fluid leaks, and one pseudomeningocele. There was one recurrent adenoid cystic tumor resulting in death and two partially resected glomus tumors. Subsequent procedures are discussed. CONCLUSION: Postoperative cranial deficits are more common after revision skull base surgery than after primary surgery. Complete resection without recurrence can be expected for revision skull base surgery. Modern reconstruction techniques reduce major postoperative complications and morbidity from cranial nerve deficits.

Adolescent↗
PubMedDate not supplied

Nasopharyngeal carcinoma with skull base invasion: a necessity of staging subdivision.

PURPOSE: To investigate prognostic values of nasopharyngeal carcinoma (NPC) with skull base invasion for optimal management, according to its extent of involvement. METHODS: From January 1985 through December 2000, 119 patients with histologically proven NPC were analyzed retrospectively with review of their computed tomography/magnetic resonance imaging and medical records. All patients underwent sequential chemoradiotherapy except 2 cases, which were treated concurrently. The mean duration of follow-up was 61 months (range 8-179). Potential prognostic factors were evaluated by univariate and multivariate analyses by the Kaplan-Meier method and the Cox model, with a particular emphasis on the extent of skull base invasion. RESULTS: Skull base invasion was found in 46 (38.6%) of 119 patients. Cranial nerve palsy and intracranial extension was discovered in 34 (28.6%) and 23 (19.3%) of these patients, respectively. The sole erosion of the skull base was not found to be a poor prognostic factor. Patients with involvement of both anterior (I-VIII) and posterior (IX-XII) cranial nerves had a worse prognosis than those with involvement of either anterior or posterior cranial nerves (P = 0.0219). The presence of intracranial extension was the worst prognostic factor in NPC with skull base invasion (P = 0.0269). The advanced neck stage and histology did not affect the prognosis of NPC in the presence of skull base invasion. CONCLUSION: Our results show that NPC with skull base invasion should be divided into the groups with, simple skull base erosion, minimal involvement of either anterior or posterior cranial nerves, multiple involvements of both cranial nerves, and intracranial extension.

Adolescent↗
PubMed1994

[Investigation of skull base in nasopharyngeal carcinoma].

100 patients with destruction of skull base in nasopharyngeal carcinoma, confirmed by pathology and CT scanning before radiotherapy, were analysed. It showed that the primary characteristics of skull base destruction are headache and cranial nerve involvement. Although the destruction of skull base showed evident manifestation in TNM classification, it can be inferred that the erosion development probably took place within 1-6 months. Comparing the CT scanning with X-ray submento-vertical view, the result indicated that the erosions of the various positions of the skull base and the invasion of paranasal sinus, cavernous sinus and orbit were clearly displayed by CT scanning but only 23% was discovered by X-ray. There was significant difference between CT scanning and X-ray, and CT scanning had more advantages. The relation between the erosion of the skull base and the invasion of parapharynx space and the metastatics of the cervical nodes were also discussed.

Adolescent↗
PubMed2005

Endoscopic endonasal surgery of the midline skull base: anatomical study and clinical considerations.

OBJECT: The midline skull base is an anatomical area that extends from the anterior limit of the cranial fossa down to the anterior border of the foramen magnum. Resection of lesions involving this area requires a variety of innovative skull base approaches. These include anterior, anterolateral, and posterolateral routes, performed either alone or in combination, and resection via these routes often requires extensive neurovascular manipulation. The goals in this study were to define the application of the endoscopic endonasal approach and to become more familiar with the views and skills associated with the technique by using cadaveric specimens. METHODS: To assess the feasibility of the endonasal route for the surgical management of lesions in the midline skull base, five fresh cadaver heads injected with colored latex were dissected using a modified endoscopic endonasal approach. Full access to the skull base and the cisternal space around it is possible with this route. From the crista galli to the spinomedullary junction, with incision of the dura mater, a complete visualization of the carotid and vertebrobasilar arterial systems and of all 12 of the cranial nerves is obtainable. CONCLUSIONS: The major potential advantage of the endoscopic endonasal approach to the skull base is that it provides a direct anatomical route to the lesion without traversing any major neurovascular structures, obviating brain retraction. Many tumors grow in a medial-to-lateral direction, displacing structures laterally as they expand, creating natural corridors for their resection via an anteromedial approach. Potential disadvantages of this procedure include the relatively restricted working space and the danger of an inadequate dural repair with cerebrospinal fluid (CSF) leakage and potential for meningitis resulting. These approaches often require a large opening of the dura mater over the tuberculum sellae and posterior planum sphenoidale, or retroclival space. In addition, they typically involve large intraoperative CSF leaks, which necessitate precise and effective dural closure.

Cadaver↗
PubMed2003

Central skull base osteomyelitis in patients without otitis externa: imaging findings.

BACKGROUND AND PURPOSE: Skull base osteomyelitis typically arises as a complication of ear infection in older diabetic patients, involves the temporal bone, and has Pseudomonas aeruginosa as the usual pathogen. Atypical skull base osteomyelitis arising from the sphenoid or occipital bones without associated external otitis occurs much less frequently and initially may have headache as the only symptom. The purpose of this study was to review the clinical and MR imaging features of central skull base osteomyelitis. METHODS: We retrospectively reviewed MR images obtained in six patients with central skull base osteomyelitis. No patient had predisposing external otitis or osteomyelitis of the temporal bone. RESULTS: All of our patients presented with headache, no external ear pain, and cranial nerve deficits. Five of six patients had a predisposition to infection, and the erythrocyte sedimentation rate was elevated in the five patients in whom it was checked. In each case, the diagnosis was delayed until MR imaging demonstrated central skull base abnormality, and the diagnosis was then confirmed with tissue sampling. The most consistent imaging findings were clival bone marrow T1 hypointensity and preclival soft tissue infiltration. Five of six patients were cured with no recurrence of skull base infection over a 2-4-year follow-up period. CONCLUSION: In the setting of headache, cranial neuropathy, elevated erythrocyte sedimentation rate, and abnormal clival imaging findings, central skull base osteomyelitis should be considered as the likely diagnosis. Early tissue sampling and appropriate treatment may prevent or limit further complications such as intracranial extension, empyema, or death.

Adolescent↗
PubMed1996

Alteration of rCBF in skull base lesions.

Cerebral functional imaging methods provide complementary information on brain function and large vessels regulatory controls which are compromised in cranial base lesions. The presence of a skull base tumor can alter regional cerebral blood flow (rCBF) in adjacent and remote brain tissue. This report presents the results of 104 CBF studies in 66 patients with skull base lesions (aged 17-75 years). The lesions included 36 meningiomas, 21 neurinomas and 9 other tumors. Regional CBF in tumor and brain tissue was measured prior to treatment using stable xenon enhanced computed tomography (Xenon(/T). For the quantitative analysis, regions of interest were delineated on tumor regions, cerebral and cerebellar hemispheres including peritumoral regions. In order to assess the remote effect of cerebellopontine angle (CPA) tumors, the brainstem, cerebellar, and cerebral blood flow were measured in 26 cases. The average brainstem CBF for patients with good outcome was higher than the average brainstem CBF for patients with poor outcome. This indicates that CBF studies in posterior fossa can be useful in predicting the prognosis of CPA tumor patients. We report a series of 16 patients with cavernous sinus tumors in whom the internal carotid artery was affected by the tumor. In nearly all cases Xenon/CT CBF studies with acetazolamide test showed no significant difference in hemispheric perfusion and a sufficient cerebrovascular reserve capacity. Interhemispheric asymmetry was present only in one patient. These results possibly indicate that i.v. administration of acetazolamide might contribute in selecting patients with higher risk for ischemic deficits after cavernous sinus surgery. Skull base meningiomas showed very high blood flow with a wide range. Local CBF in the peripheral region of meningiomas was higher than in the central region. Blood flow values in the peritumoral areas are about 30% lower than those of the ipsilateral hemisphere. In individual cases, blood flow values in the peritumoral low-density area on CT were extremely low. It is concluded that CBF studies in skull base tumors are valuable in treatment planning. Xenon/CT can be useful additional diagnostic procedure in the evaluation of skull base surgery candidates.

Acetazolamide↗
PubMed2001

Lateral craniofacial approaches to the skull base and infratemporal fossa.

The field of skull base surgery has expanded dramatically the surgical horizons in the treatment of skull base neoplasms, which, previously, were considered inoperable because of their locations and relation to vital structures. This article aims to offer improved understanding of surgical indications and appreciation for some of the details of surgical techniques involved.

Cranial Fossa, Posterior↗
PubMed1996

Clinical relevance of somatostatin receptor scintigraphy in patients with skull base tumours.

The differential diagnosis of tumours in the skull base is often difficult. With the experience that various intracranial tumours differ in their expression of somatostatin binding sites (SBS) somatostatin receptor scintigraphy (SRS) with the somatostatin analogue octreotide can give additional information of the tumour entity. Seventy patients with various tumours of the skull base were examined with 111Indium-labelled DTPA-octreotide injected i.v.. Planar and tomographic images were obtained with a gamma camera 4-6 and 24 hours after injection. All of the meningiomas (unifocal and multifocal tumours in various locations) showed a high density of SBS whereas in none of the examined neurinomas SR were found. Pituitary adenomas revealed in only 50% SR in different concentrations and independent of the endocrine activity. SRS can help in the differential diagnosis between meningiomas and other tumours, postoperative scar or radionecrosis at the skull base. A dural infiltration with meningioma tissue ("meningeal sign") may be discriminated from a reactive hypervascularisation in lesions with a diameter > 0.5 cm. We conclude that SRS can offer additional diagnostic aspects in the pre- and postoperative management of patients with skull base tumours.

Adenoma↗
PubMed2002

Lateral skull base malignancies.

OBJECT: Historically poor outcomes have been characteristic in patients with lateral skull base malignancies. As advances in skull base surgical techniques have been made, complete resection has increasingly been achieved. This has resulted in improved survival rates and local tumor control. METHODS: The authors performed a retrospective review of 95 patients treated for lateral skull base malignancies. The mean age of the patients was 49.4 years. There were 44 females and 51 males. The mean follow-up period was 50 months. Resection was performed in all patients, and postoperative radiotherapy was undertaken in 54% of the cases. Local disease control was maintained in 73% of the patients. Tumor involvement of the facial nerve and intracranial tumor extension did not jeopardize the rate of local control. CONCLUSIONS: Despite the fact that technical advances in skull base surgery have resulted in a higher incidence of complete tumor resection and improved survival rates, a respect for the poor prognosis historically associated with lateral skull base malignancies should be maintained and treatment should be appropriately aggressive.

Adolescent↗
PubMed2002

[Election for surgery access to skull base].

OBJECTIVE: To seek for a better approach for the resection of skull base tumors. METHODS: A review of 84 skull base tumors resection employed unlike operative approach in the Cancer Hospital of Chinese Academy of Medical Sciences was presented. Surgical approach feature of invaded the different position of skull base, selects the best operative access for safely removes the tumor, protects the critical structure of skull base as fully as possible, and decreases the complication were discussed in this article. RESULTS: Fourteen cases of benign and seventy cases of malignant underwent surgery. The tumor in 38 cases implicated parapharyngeal space and skull base. The lesion synchronously involved the anterior and middle cranial fossa in 7 cases, middle and posterior cranial fossa in 13 cases, lateral cranial base in 26 cases. The survival rate at 3 years was 68.5% (27/40) for malignant tumor. There was no operative death and severe complication in this series. CONCLUSION: To select the best operation access should think over following factors: 1. Tumor position and the scope implicated. 2. Safely and fully removal of the tumor. 3. The limited destroy to normal function structure and receivable cosmetic effect. 4. It is convenient to reliable reconstruction.

Adolescent↗
PubMed2005

Endoscopic surgery of the anterior skull base.

OBJECTIVES/HYPOTHESIS: Traditional surgical approaches to the anterior skull base often involve craniotomy, facial incisions, disruption of skeletal framework, tracheotomy, and an extended hospital stay. As experience with endoscopic sinus surgery has grown, the techniques and equipment have been found to be adaptable to treatment of lesions of the anterior and central skull base. A minimally invasive endoscopic approach theoretically offers the advantages of avoiding facial incisions, osteotomies, and tracheotomy; surgery should be less painful, recovery quicker, and hospital stays should be shorter. The study attempted to assess endoscopic approaches to the anterior and central skull base for its ability to achieve those goals. STUDY DESIGN: Retrospective review of 72 cases performed at a single institution from November 1996 to July 2003. A subgroup of 15 patients who underwent endoscopic approach to their pituitary tumors was compared with a similar group of 15 patients who underwent traditional open trans-sphenoidal surgery for their pituitary tumors. METHODS: Patient records were analyzed and information tabulated for age, sex, disease, location of lesion, operative time, use of image-guided surgical systems, blood loss, length of intensive care unit stay, duration of operative pain, length of postoperative hospitalization, complications, and completeness of resection. RESULTS: Of the cases, 86.1% were performed exclusively endoscopically, and 13.9% used a combination of endoscopic and open techniques. An image-guided surgical system was used in 83% of cases. Hospital length of stay was 2.3 days for the exclusively endoscopic group as opposed to 8 days for the combined group. With the patients with pituitary tumors, operative times were similar between the two groups (255.13 vs. 245.73 min), blood loss was less in the endoscopic group (125.33 vs. 243.33 mL), pain duration was shorter in the endoscopic group (10 of 15 patients pain free on postoperative day 1 vs. 2 of 15 patients pain free in the open group), and intensive care unit stay and hospital length of stay were both shorter in the endoscopic group. Complication rates and completeness of resection was similar in both groups, although the open group had a higher rate of complications related to the approach to the sella. CONCLUSION: The study demonstrated the safety and efficacy of judicious endoscopic approaches to anterior skull base lesions. An outcomes assessment in pituitary surgery demonstrates advantages of an endoscopic approach in appropriate cases.

Adolescent↗
PubMed2004

Missile injuries of the anterior skull base.

Missile injuries of the anterior skull base usually occur during war or war-like situations. These injuries may be isolated or associated with multiple traumatic injuries. We report 23 such cases managed during military conflicts and peacekeeping operations. All were adult males. Four of these patients sustained bullet injuries; the rest were injured from shrapnel. Eighteen patients had injury to the visual apparatus with permanent blindness. Proptosis was seen in 16, cerebrospinal fluid (CSF) leak from the wound in seven, and CSF orbitorrhea in three patients. Sixteen had irreparable injury to the eye necessitating evisceration/enucleation, and two had retrobulbar optic nerve injury. Three patients were comatose [Glasgow Coma Scale (GCS) 3/15], and 14 had altered sensorium. Six patients were fully conscious. All were investigated by computed tomography (CT), which revealed injury to the eyeball and skull base, orbital fracture, frontal hematoma, contusion, and pneumocephalus. Seventeen patients underwent emergency surgery, and six patients were initially managed conservatively. Neurosurgical management consisted of making bifrontal flaps, craniotomy/craniectomy, debridement, and repair of the base with fascia lata. Reconstruction of the orbital rim was required in three cases. All were managed postoperatively with cerebral decongestants and antibiotics in anti-meningitic dosages. There was one death in the postoperative period; outcome was good in 16 and moderate in four patients. Twelve patients had retained intracranial splinters; three of these developed recurrent suppurative meningitis. Of the six patients initially managed conservatively, three were subsequently operated for CSF rhinorrhea. Gross communition, dural loss, and injury to the frontal scalp often preclude the use of pericranial repair of the skull base. Fascia lata is extremely useful for reconstruction and repair. Anterior cranial fossa injury probably carries a better prognosis; however, there is increased risk of suppurative complications due to breach of air-filled sinuses by the missile and contamination of the intradural compartment, as compared with supratentorial vault injuries not involving the orbit or paranasal sinuses. Three patients who underwent no operative procedure and remain asymptomatic are under follow-up.

Journal Article↗
PubMed2003

[Sectional anatomy and computer-assisted three-dimensional reconstruction of lateral skull base in normal].

OBJECTIVE: To investigate the sectional anatomy of lateral skull base in normal and provide data for diagnosis and selecting surgical approach of lesions of lateral skull base. METHOD: Three sets of coronal sections with plastination technique was made and investigated for the location, direction and mutual relationship in different section. Signals of some structures were extracted to reconstructed three-dimensional image. RESULT: The section with plastination displayed distinct nerve, muscle, vessel, bone in lateral skull base. The structures of lateral skull base were described in five typical section: the maxillary sinus, pharyngeal orifice of pharyngotympanic duct, foramen ovale, tympanie orifice of pharyngotympanic duet, inner auditory meatus. The three-dimensional images of sphenoid sinus, ethmoid sinus, trigeminal nerve, pharyngotympanic duet and inner carotid artery after extracted the signals in serial sections. CONCLUSION: Sectional anatomy with plastination contributed to understanding complicated anatomic structure including the location and mutual relationship, three dimensional image can vividly display the structure underlying lateral skull base surgery.

Humans↗
PubMed1993

Skull base approaches to complex cerebral aneurysms.

The authors used skull base approaches to improve the surgical treatment of cerebral aneurysms. These approaches facilitate aneurysm surgery by allowing early proximal and distal vascular control, shortening and widening of the operative field, increasing the range of the surgeon's operative view and motion, and alleviating brain retraction. Twenty-two patients with ruptured giant or complex aneurysms were operated upon acutely using skull base approaches appropriate for their location: (1) the orbitocranial approach for anterior circulation, ophthalmic artery, and intracavernous lesions (n = 10); (2) the orbitozygomatic approach for aneurysms of the upper third of the basilar artery (n = 6); (3) the petrosal approach for aneurysms of the middle third of the basilar artery (n = 2); and (4) the far lateral-transcondylar approach for vertebrobasilar aneurysms (n = 4). Clipping and dissection of the aneurysms was facilitated by the skull base approaches. No surgical mortality occurred in this series of patients; transient cranial nerve paresis was the only morbidity related to the approaches. We compare the three-dimensional spatial geometry of skull base and conventional approaches, and discuss the advantages and nuances of skull base approaches.

Adult↗
PubMed2001

Computer assisted tumour resection of the skull base: case report.

This case report demonstrates computer assisted resection of a skull base tumour after combined chemotherapy and irradiation, in a 40-year-old man with a squamous cell carcinoma of maxilla, zygoma, orbit and skull base. The resection of the skull base was performed with computer assistance after conventional resection of the maxilla, midface, exenteration of the orbit and lymph node dissection. Following combined chemotherapy and irradiation, the original, pretherapeutic tumour extent was marked on the new, presurgical CT scan enabling resection of the skull base with the use of a navigation microscope. Thus planned resection from the presurgical CT could be transposed intraoperatively using the navigation system, and the skull base could be resected with precision.

Adult↗
PubMed1994

Sellar and parasellar lesions involving the skull base.

Lesions of the central skull base, most notably the sphenoid bone, commonly originate from the endocranial soft tissues. Although most commonly identified with pituitary macroadenomas, skull base erosion, destruction, and remodeling may be seen with a variety of congenital, neoplastic, cystic, vascular, and inflammatory lesions involving the sellar and parasellar soft tissues.

Bone Diseases↗
PubMed2001

Attenuation of radiation dose by the skull base bone in patients with nasopharyngeal carcinoma: clinical importance.

PURPOSE: To measure the degree of attenuation of radiation dose by the skull base bone in patients with nasopharyngeal carcinoma (NPC) and to study its clinical importance. MATERIALS AND METHODS: Isodose distribution in 11 patients with NPC who received bilaterally opposed large-field irradiation (1.8 Gy per fraction) was studied with a three-dimensional treatment planning system with tissue inhomogeneity correction. Also studied were the sites of local tumor recurrence in 37 patients with NPC and skull base destruction (>/=0.5 cm) or intracranial invasion treated with radiation therapy from January 1989 to December 1992. Regression analyses were performed. RESULTS: In the dosimetric study, the low-dose areas (<1.65 Gy) were located at the level of the skull base in all 11 patients. A significantly positive correlation between the maximum width of the skull base bone and the low-dose volume (<1.65 Gy) was demonstrated (P =.003, linear regression). In the clinical study, local tumor recurrence was noted in 18 patients (49%). The sites of local recurrence included skull base in 16 patients (43%) and nasopharynx in six patients (16%). Wider skull base bone was a significant predictor of skull base recurrence after radiation therapy (P =.03, logistic regression). CONCLUSION: Herein demonstrated is the inadequacy of the radiation dose over the skull base due to attenuation by the skull base bone. The relationship between width of skull base bone and skull base tumor recurrence also is established.

Adult↗