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At least 19 recordsLinked to original sources

Cystic schwannoma of the sphenoid sinus and skull base.

Skull base and intracranial cystic schwannomas are rare tumors. To our knowledge, a cystic schwannoma involving the sphenoid sinus has not been previously reported. The location and fluid-filled nature of the lesion resulted in an erroneous preliminary diagnosis of a destructive sphenoid sinus mucocele. Endoscopic biopsy and decompression established the correct diagnosis and reversed a progressive visual loss until definitive surgical removal of the lesion was accomplished. Diagnostic evaluation, histologic findings and management strategies are discussed.

Humans↗

Role of brachytherapy in the management of the skull base meningioma. Treatment of skull base meningiomas.

BACKGROUND: The treatment of primary and recurrent skull base meningiomas presents a formidable surgical problem. METHODS: Fifteen patients with primary and recurrent skull base meningiomas were treated by means of interstitial irradiation with iodine 125 (125I) seed implantation. The physical characteristics of 125I enabled the authors to administer a minimum tumor dose ranging from 100 to 500 Gy at a low dose rate of 0.05-0.25 Gy per hour. RESULTS: All 15 patients are alive at a median follow-up of 29 months. Of the 15 patients, 2 with calcification and 2 without calcification achieved only partial responses. The remaining 11 patients achieved a complete response. No early or late complications were observed. CONCLUSIONS: From these data, the authors conclude that interstitial irradiation with 125I seeds is an effective, safe, and simple method in the treatment of both recurrent and primary skull base meningiomas.

Adult↗

Pituitary adenoma invading the skull base--a strategy for skull base surgery.

A strategy for surgical management, including the approach and preoperative evaluation, of pituitary adenoma invading the skull base is described. Preoperative evaluation requires a balloon occlusion test of the internal carotid artery (ICA) to determine tolerance to occlusion. Failure to tolerate occlusion indicates administration of brain protective agents and/or a bypass procedure before tumor removal. The transsphenoidal, pterional, orbitofrontomalar, and infratemporal fossa approaches are all suitable for various tumor locations. A combined orbitofrontomalar and extended frontal approach allows removal of tumor with extensive invasion and is suitable for bypass procedures. Preoperative evaluation of ICA occlusion can prevent development of hemodynamic stroke. We treated five patients with pituitary adenoma invading the skull base, including two primary and three recurrent cases. All symptoms improved, but temporary oculomotor nerve disturbance occurred in three patients and anosmia in one. Reoperations for recurrent pituitary adenomas were effective in reversing the symptoms. No hemodynamic stroke was seen postoperatively. These tumors, except for drug-responsive cases, are indicated for skull base surgery.

Adenoma↗

A surgical method for treating anterior skull base injuries.

Skull base surgery was performed on 18 patients with anterior skull base injuries. The operative technique consisted of opening the operative field in the anterior skull base via a coronal incision and a frontal craniotomy, debridement of the anterior skull base including the injured dura mater, performing drainage from the anterior skull base to the nasal cavity by ethmoidectomy, and reconstructing the resulting dural and anterior skull base defect using bilateral temporal musculo-pericranial flaps and a bone graft. Seventeen of the 18 patients recovered without any complications, although epidural abscesses in the anterior skull base had been present in four patients at the time of the operation. Only one patient developed an epidural abscess in the anterior skull base after the operation. None of the patients developed any other complications including meningitis, recurrent liquorrhoea or cerebral herniation. Satisfactory aesthetic results were achieved in 16 of the 18 patients. In one patient, uneven deformity of the forehead, which was caused by the partial sequestration of the frontal bone due to postoperative infection, was observed. In another patient, a depressed deformity of the forehead, which was caused by the partial loss of the frontalis muscle following the use of the frontal musculo-pericranial flap instead of a temporal musculo-pericranial flap, was observed. Anterior skull base reconstruction using bilateral temporal musculo-pericranial flaps provides excellent results in terms of patient recovery and aesthetics.

Adolescent↗

Secondary craniofacial problems following skull base surgery.

Skull base wounds remain the most challenging that a skull base surgeon faces because of the unique and unforgiving requirements of the intracranial compartment. To successfully reconstruct these defects after complex exposure and radical resection around vital structures, a most conservative approach must be taken (i.e., one must choose the option that has the greatest chance to be successful, even if it means taking the extra time and effort of doing a free tissue transfer). Indeed, one can take no short cuts if the skull base would be left with a tenuous repair. Close postoperative surveillance of the patient for complications and maximal medical management is essential. Because of the difficulty of examining the hidden skull base wound postoperatively, surgeons must have a low threshold for re-exploration if a complication is suspected. As the first decade of the multidisciplinary skull base team approach passes, and long-term results are being assessed, the question of "is it worth it?" is fair. The reported series are showing increased survival rates and decreased complication rates. Therefore, the answer would appear to be "yes". The question is best answered, however, by the individual patient who previously had no hope for treatment of his or her deep-seated skull base tumor.

Adult↗

Imaging of the skull base.

Skull-base imaging has been a key factor in the advancement of skull-base surgery. The analysis of MR imaging or CT of the skull base emphasizes important landmarks, which are key to surgical planning. Although the definitive diagnosis usually is done by biopsy, the radiologist can limit the list of possibilities of the identity of a skull base lesion. The apparent site of origin is a key factor. Separation of cystic abnormalities from more solid enhancing abnormalities also is critical.

Biopsy↗

Surgical reconstruction after extensive skull base surgery.

Skull base surgery is a rapidly expanding surgical subspecialty bringing together the sophisticated surgical skills of the neurotologist-head and neck surgeon and the neurosurgeon. Newly described surgical approaches to the skull base have made possible greater surgical ablation of the skull base region, resulting in large defects and thus heightening the need for reconstructing these regions. Prevention of cerebrospinal fluid leaks is the most important aspect of reconstruction and is achieved most readily when possible by dural patch grafts of fascia lata, coverage of the dura with soft tissue, and preservation of the soft tissue utilizing skin or split thickness skin grafts. Soft tissue may be in the form of free fascia lata grafts, pedicled galeal flaps, or local or regional skin flaps. Defects of the skull base larger than a few square centimeters are best reconstructed with local or regional skin flaps or musculocutaneous flaps. These flaps lend sufficient structural support so that bone support is not usually required. Subsequent cranioplasty, when necessary, can provide protection to those regions of the brain that are more susceptible to blunt trauma.

Cranial Fossa, Posterior↗

Surgical treatment of anterior skull base tumours.

Skull base tumours represent a special challenge to surgeons due to the complex anatomy of the area. While small tumours are easy to remove, large lesions can pose complex situations. The most difficult aspects are not only the approach and removal, but specially the repair of the defects created by the resection of the tumour. We present here our experience with the surgical removal of tumours on the anterior skull base. To achieve a good approach, we resort to a bifrontal craniotomy including the cilliar arches. To obtain a skull base bone flap that can be used for repair at the end of the procedure, we remove the roof of the nose and a part of the medial wall and roof of both orbits. While the tumour is removed, the skull base bone flap is autoclaved to kill all tumoural cells. At the end of the procedure this bone flap is replaced, wrapped with a flap of pericranium. Provided no orbit needs to be emptied, no other flap is needed to reconstruct the area. One advantage is that the surgical cavity is not occluded with tissues, thus facilitating early identification of any recurrence. The area can be explored with the aid of an endoscope introduced into the nasal cavities through the nostrils, and in case of doubt, biopsies taken from all suspicious area. Our technique facilitates the repair of the surgical defect, and while not compromising the healing process it has a very low incidence of CSF leaks and infections.

Adolescent↗

Prevention of postoperative complications in skull base surgery for nasal or paranasal sinus carcinoma invading the skull base.

With recent technical advances in skull base surgery, radical resection of a nasal or paranasal sinus carcinoma invading the skull base can now be achieved. To assure a satisfactory surgical result, it is essential to prevent postoperative infection. In our series of 14 cases, serious postoperative infections occurred in the earliest 10 cases, and only 2 of these patients are still alive. The vascularised abdominal muscle flap for skull base reconstruction was fixed with fibrin glue, but was not adequate to fill the dead space, resulting in cerebrospinal fluid leakage and subsequent meningitis. Once the infection occurred, a free bone flap became the focus of infection. Based on these earlier experiences, we used a ROC fastener system to completely fill the dead space with an abdominal muscle flap, and bone flap was primarily craniectomised in the four most recent cases. With this technique, there were no postoperative infections.

Abdominal Muscles↗

[Institutionalization of skull base surgery. Development, concept and initial experiences of the interdisciplinary center for skull base surgery of the Leipzig University].

The treatment of complex tumorous, inflammatory, traumatic, vascular processes, or developmental disorders of the skull base increasingly needs the interdisciplinary cooperation of specialties involved in diagnostics or treatment. Due to this inevitable cooperation of different hospital specialties, institutionalization of skull base surgery, organized as a center or working group, seems recommendable. Moreover, such a center may have additional effects on the external representation of skull base surgery, which is also important. On the initiative of 11 departments and institutes of the university hospital of Leipzing, the Interdisciplinary Center of Skull Base Surgery (IZSL) was founded in March 1997. The following aims were proclaimed: improvement of the interdisciplinary clinical treatment of patients with skull base diseases, evaluation of the patient's data, advancement of clinical and experimental research on the field of skull base surgery, as well as the organization of meetings for training and teaching and scientific meetings. Structure, concept, and first experiences of the interdisciplinary center of skull base surgery are discussed.

Germany↗

A millennium review of skull base surgery.

Skull base surgery is a recent development in our history, in as much as most of the surgical techniques involved have been described within the last century. To provide an historical prospective the author reviews the development of this specialty, arbitrarily dating its beginning some five centuries ago with the work of Leonardo da Vinci. By picking this period we include the origin of scientific anatomy and personages interested in developing new ideas and concepts who were able to leave the stagnant period of the Middle Ages behind. In 1900 surgeons worked alone, with the concept of a skull base "team" not yet existing. Endotracheal intubation and controlled respiration was just being introduced. Intraoperative monitoring of blood pressure, pulse rate and respiration was not yet known. Harvey Cushing was to introduce this concept in the first decade of the last century. This survey traces the origins of modern skull base surgery from its antecedents in the Renaissance to the beginning of this century. A paper of this length can only provide a sampling of themes and personalities; nevertheless, it will give the reader an impressive overview of how far we have come and some ideas of what the future holds.

History, 15th Century↗

Imaging of postnatal maturation of the skull base.

The skull begins to form when mesenchyme thickens and condenses around the developing brain. At the skull base, most of this mesenchyme derives from neural crest, and some arises from general head mesenchyme. This article reviews the patterns for maturation of the ossification, sutures, and synchondroses in the occipital, the sphenoid, and the orbitoseptal regions, and reports additional data derived from specific study of CT scans of the skull base in children and young adults.

Adolescent↗

A new measure of growth efficiency: skull base height.

Skull base height increases significantly with better nutrition and health conditions, as seen in comparing 163 nineteenth to twentieth century dissecting-room skeletons (Terry Collection) with 237 modern American middle-class adults (forensic and willed skeletons). The increase parallels the change in pelvic inlet depth index, known to respond sensitively to nutrition, and in stature, and is over six times greater than the general skull size change. Skull base height (porion-basion) is easy to measure with depth gauge and sliding caliper, or by subtraction, and is in adult a sensitive indicator of childhood growth stress.

Age Determination by Skeleton↗

Imaging of mucormycosis skull base osteomyelitis.

Skull base osteomyelitis (SBO) is typically bacterial in origin and caused by Pseudomonas, although the fungus Aspergillus has also rarely been implicated. SBO generally arises from ear infections and infrequently complicates sinonasal infection. Rhinocerebral Mucor infection is characteristically an acute, fulminant, and deadly infection also affecting the orbits and deep face and is associated with intracranial complications. Bony involvement is uncommon because of the angioinvasive nature of the fungus. More recently, chronic invasive Mucor sinusitis has been described. We report the unusual clinical and imaging features of a patient with biopsy-proven invasive mucormycosis arising from chronic isolated sphenoid sinus disease, who presented with extensive SBO and a paucity of deep facial, orbital, or intracranial involvement.

Biopsy↗

Evaluation of skull base erosion in nasopharyngeal carcinoma: comparison of plain radiography and computed tomography.

Over a period of 16 months, a total of 175 patients with newly diagnosed nasopharyngeal carcinoma (NPC) were evaluated with plain radiography and computed tomography (CT) of nasopharynx and base of skull. 54 of 175 patients (30.9%) had CT evidence of skull base erosion. Plain radiography failed to demonstrate the skull base erosion in 22 of 54 patients (40.7%) and underestimated the extent of bony involvement in another 21 patients (38.9%). In 14 of 54 patients (25.9%), there was also false suspicion of bony erosion in the plain films in one or more regions of the skull base which was not substantiated by CT and subsequent clinical course. The present study shows that plain radiography lacks sensitivity and specificity in detecting skull base erosion by NPC. CT evaluation of NPC patients should include thin CT sections of base of skull for detection of subtle bone erosion, and this would allow better decision concerning the shielding of the pituitary-hypothalamic axis during radiotherapy for improvement in therapeutic ratio. For the investigation of individuals highly suspicious of harboring NPC, even when the plain radiography is negative, CT should still be performed as this may give the only clue to the presence of a small submucosally spreading NPC.

Humans↗

Endoscopically assisted anterior cranial skull base resection of sinonasal tumors.

The traditional approach to sinonasal tumors involving the base of skull has been the anterior craniofacial resection. Endoscopic techniques have created the potential to approach the intranasal aspect of skull base lesions without external incisions and still develop an en bloc resection when removed. We report our initial experience with skull base neoplasms in which the otolaryngic portion of the standard resection was accomplished instead through an endoscopic approach. The nature of lesions favorable for this approach and associated technical issues are discussed. Although we do not consider this approach a replacement for the traditional anterior craniofacial resection, it is an important adjunct in the skull base surgeon's armamentarium.

Adenocarcinoma↗

Magnetic resonance imaging of the central skull base.

The central skull base is an anatomically complex region whose foundation is the sphenoid bone. It includes the sphenoid sinus, clivus, and sella turcica, as well as adjacent soft tissues such as the cavernous sinuses and nasopharynx. The central skull base may be affected by pathologies intrinsic to the sphenoid bone or by processes that arise in adjacent soft tissue and extend centrally to affect the central skull base. In general, this region is optimally imaged with magnetic resonance scanning, although in some cases computed tomography can provide complementary information. In this review, we will discuss a variety of pathologies that can affect the central skull base, such as neoplasms, infections, trauma, congenital malformations, and a variety of miscellaneous pathologies. We will discuss processes that can mimic neoplasia, such as aggressive polyposis and chronic inflammatory disease. For each pathology we will review clinical and imaging findings.

Diagnosis, Differential↗

Computer-assisted image-guided surgery in pediatric skull-base procedures.

Skull-base surgery is characterized by the variety of important neural and vascular structures within a narrow operating field. Although preoperative imaging by computed tomography (CT) and magnetic resonance imaging (MRI) and the use of microsurgical techniques have improved intraoperative orientation, a large number of complications still are caused by localization problems. Especially in pediatric skull-base surgery, maximum localization accuracy during surgery is required. The authors developed a localizing system based on tomographic imaging (such as CT or MRI) to achieve safer surgery by providing highly accurate location information. The preliminary successful experience in the use of the Aachen computer-assisted surgery device for pediatric skull-base surgery (14 cases) is presented. Indication include juvenile angiofibroma of the nasopharynx, infectious and tumorous diseases of the paranasal sinuses, orbital tumors, foreign bodies, and intracranial abscess formation.

Adolescent↗