Use of neurosurgical techniques for removal of a cardiac tumor.

A 6-week-old male infant with a capillary hemangioma of the right atrioventricular groove adjacent to the right coronary artery and conduction system underwent successful resection with the aid of microneurosurgical instrumentation. The technical challenge was thought to be analogous to that encountered by microneurosurgeons in their dissection of brain tumors.

Pregnancy-associated subacute hemorrhage into a prolactinoma resulting in diabetes insipidus.

A young woman with a small pituitary tumor associated with hyperprolactinemia developed subacute intrapituitary hemorrhage during the third trimester of pregnancy and presented with central diabetes insipidus. Magnetic resonance imaging established the diagnosis. After transsphenoidal surgery, her visual findings resolved, and the patient had an uneventful spontaneous delivery.

Transcallosal, transventricular approach to a basilar apex aneurysm.

A new approach to the basilar apex in a patient with a megadolichobasilar anomaly and an abnormally rostral basilar apex aneurysm is described. The details of the surgical approach and the advantages and limitations of this transcallosal, interseptal approach are described.

Split-calvaria osteoplastic rotational flap for anterior fossa floor repair after tumor excision. Technical note.

A split-calvaria osteoplastic rotational flap to repair the anterior fossa floor after tumor excision was devised and tested clinically. At surgery, the flap is outlined between the glabella and the vertex. After the pericranium between the glabella and the flap's anterior pole is elevated to form its pedicle, a full-thickness craniotomy is performed to expose the diploic aspect of the bone graft donor site (when the graft is relatively wide, bifrontal craniotomies may be advantageous). The diploic space is split in situ, taking care to protect the pedicle and its attachments to the osseous segment. Linear osteotomies in the outer table are created to mobilize the flap. With the flap rotated frontally, the craniotomy is completed. After tumor extirpation, the margins of the osseous segment of the flap are shaped to conform to the defect of the anterior fossa floor. Transverse osteotomies are performed so that the graft's convex curve conforms to that of the anterior fossa floor. The flap is then rotated into position. Follow-up evaluation in two patients at 22 and 30 months demonstrated bone integrity of the anterior fossa floor with graft preservation. Transient postoperative cerebrospinal fluid (CSF) rhinorrhea, which occurred in Case 1, was avoided in Case 2 by placing the osseous segment of the graft coplanar with the bone floor of the fossa. Neither patient had late meningitis or CSF rhinorrhea. The split-calvaria osteoplastic rotational flap may represent an advance toward the ideal reconstruction of the anterior cranial fossa floor.

Erythropoietin-augmented isovolemic hemodilution in skull-base surgery. Case report.

Human erythropoietin in concert with intraoperative hemodilution, tumor embolization, and surgical staging was used to manage a red blood cell mass in an anemic Jehovah's Witness patient with a hypervascular meningioma. Erythropoietin (3000 U thrice weekly) and oral iron (1300 mg daily) were given for 1 month prior to surgery, raising the hemoglobin level from 11.8 to 14.1 gm/100 ml. A posterior fossa craniectomy combined with a temporal craniectomy was then performed so that partial petrosectomy, section of the transverse sinus, incision of the tentorium, and exposure of the lesion could be carried out. The first stage of the surgery was terminated immediately prior to tumor mobilization. Isovolemic hemodilution was initiated just before the skin incision. Postoperatively, the hemoglobin concentration dropped to 11.5 gm/100 ml. The erythropoietin dose was doubled and administration of oral iron continued, leading to a hemoglobin level of 14.0 gm/100 ml at 1 month after the first operation. The tumor was embolized using superselective catheterization. The next day, at the second stage of the surgery, the tumor was extirpated, again employing isovolemic hemodilution. By the 4th postoperative day, the hemoglobin level had dropped to 9.4 gm/100 ml. The patient made an uncomplicated recovery. Erythropoietin therapy contributed substantially to the successful outcome of this case. Since erythropoietin has the potential to augment all other forms of autologous banking, its role in elective neurosurgery may become increasingly important in an era of heightened concern about heterologous transfusion.

Transoral-transclival clipping of a giant lower basilar artery aneurysm.

The authors discuss the choice of the transoral-transclival approach for the repair of a lower basilar artery aneurysm in a 32-year-old sickle-cell patient. Efficiency of approach and minimization of damage to vital structures support the use of this technique. The risks of cerebrospinal fluid fistula and meningitis are considered. One year after operation, the patient is neurologically intact.

Transcranial translabyrinthine approach to vestibular schwannomas.

Surgeons who utilize the suboccipital approach for the removal of large vestibular schwannomas, can perform a planned labyrinthectomy from within the intracranial cavity via the suboccipital exposure. This transcranial translabyrinthine approach provides one of the major advantages of the conventional transmastoid translabyrinthine approach, namely, unambiguous identification of the facial nerve as it exits the internal auditory canal, without the need for complete mastoidectomy and labyrinthectomy. The labyrinthectomy is best performed prior to the complete exposure of the internal auditory canal. The approach requires the surgeon to identify the endolymphatic sac intracranially, then drill the temporal bone and follow the vestibular aqueduct to the utricle. The lateral and superior semicircular canal ampullae, the superior vestibular nerve, Bill's bar, and the facial nerve at the lateral end of the internal auditory canal can then be identified. After testing on multiple cadaver temporal bones, this approach was used in patients with large tumours that extended far laterally in the internal auditory canal. The steps in the technique are described in detail.

The transcranial translabyrinthine approach to acoustic neuromas.

We originally described the transcranial translabyrinthine approach (TCTL) to acoustic neuroma. The approach is a labyrinthine dissection that is performed via the suboccipital exposure. It allows a complete and direct visualization of the internal auditory canal and the identification of the facial nerve at "Bill's bar." The TCTL enhances the suboccipital approach and adapts to its concepts of the classical transmastoid translabyrinthine approach. We hereby report our initial experience with the TCTL and present the surgical results in six additional cases. We also discuss the indications of this approach and compare it to alternative approaches that are used for the removal of large acoustic neuromas that extend laterally in the internal auditory canal.

Atypical invasion of the temporal bone in vestibular schwannoma.

Vestibular schwannomas typically present with erosion of the temporal bone that is limited to the boundaries of the internal auditory canal. Four patients with extensive erosion, excavations, and pseudosatellite defects in the petrous apex are presented. These bony changes extended anteriorly up to the level of the carotid canal. The patients did not have stigmata of neurofibromatosis type 2 and they did not have systemic bony disorders. The tumors did not show any unusual histopathologic changes. Such invasive tumors present an unusual surgical challenge compared to vestibular schwannomas with a more typical pattern of bony erosion. Radiological features and surgical considerations relevant to vestibular schwannomas with this rare presentation are discussed.

Periaqueductal approach to cholesterol granulomas of the petrous apex.

The periaqueductal approach for the drainage of cholesterol granulomas of the petrons apex is described. As with previously reported approaches, the periaqueductal approach takes advantage of the high pneumatization of the temporal bone in this disease. It requires dissection of the supralabyrinthine air cell tract as well as air cells medial to the posterior semicircular canal. This requires a circumferential bony dissection, skeletonization, and preservation of the vestibular aqueduct and the identification of the internal auditory canal. This periaqueductal approach preserves hearing and provides an alternative to the infralabyrinthine and infracochlear approaches when their use is precluded by variations in the temporal bone.

Aggressive papillary tumors of the endolymphatic sac: clinical and tissue culture characteristics.

Aggressive papillary tumors of the temporal bone are neoplasms that were recently re-classified as tumors of the endolymphatic sac. They typically invade the mastoid bone and otic capsule and can grow into the petrous apex. The authors have treated three patients with this rare neoplasm and grown one of the tumors in tissue culture. This report reviews the clinical presentation in the three patients and the immunohistochemical staining characteristics of the tumor and tumor culture as compared to those of the endolymphatic sac. Findings support the hypothesis that aggressive papillary lesions of the temporal bone arise from the endolymphatic sac. Additionally, it is noted that the tumor culture maintains the characteristics of the original tumor and thus provides an exciting laboratory model for further study of this rare neoplasm.

Pigmented villonodular synovitis of the temporomandibular joint. Case report and review of the literature.

A case of pigmented villonodular synovitis of the right temporomandibular joint with extension through the base of the skull into the middle cranial fossa is described. The patient initially had right-sided hearing loss. Physical examination revealed a mass in the right ear canal. Computerized axial tomography demonstrated a destructive lesion of the right temporomandibular joint, with extension into the middle cranial fossa. The surgical approach is discussed, and the 11 previously reported cases are reviewed.

Opsoclonus-myoclonus syndrome: correlation of radiographic and pathological observations.

We report a case of a child with opsoclonus-myoclonus syndrome. Neuroradiological studies indicated a lesion in the cerebellar vermis. A cerebellar biopsy revealed changes consisting of Purkinje and granular cell loss with gliosis. This case report documents the correlation of radiologic and pathological findings in a patient with opsoclonus-myoclonus syndrome.