To describe the detailed microsurgical anatomy of the clinoid(C5)segment of the internal carotid artery(ICA) and surrounding structures and clarify the anatomical relationships of this region emphasizing their clinical relevance, authors examined in 70 specimens from 35 formalin fixed cadaveric heads. Removal of the anterior clinoid process exposes the C5 segment of the ICA which is encircled by the thin inner dural layer of the cavernous sinus wall. Opening this membrane enables entrance into a narrow space that communicates with cavernous sinus through the proximal dural ring. Unlike the dura of the distal dural ring that is tightly attached to the ICA, the proximal dural ring is always incompetent. The C5 segment of the ICA has been considered by the majority of authors to be extracavernous. This understanding developed because most investigators overlooked the thin inner dural layer encircling the clinoid ICA. The narrow space between the inner dural layer and the ICA communicates with cavernous sinus through an incompetent proximal dural ring. Therefore, the clinoid ICA should be considered to be the most rostral portion of the cavernous (C4)segment of the ICA. The proximal dural ring is a surgical landmark rather than a true dural ring.
Cadaver ; Carotid Artery, Internal* ; Cavernous Sinus ; Formaldehyde ; Head ; Humans ; Membranes ; Research Personnel

OBJECTIVE: Various lesions including tumors occupying in the presellar and suprasellar regions have been traditionally removed by the transcranial approach. The new modified transsphenoidal approaches(TSAs) have been proposed to avoid the craniotomy and to get better surgical view. MATERIALS AND PATIENTS: The sellar floor and presellar anterior cranial fossa were removed through the sublabial transseptal transsphenoidal technique in the "transsphenoidal supradiaphragmatic intradural approach". One tuberculum sella meningioma and a suprasellar Rathke's cleft cyst confined to the pituitary stalk were removed via this approach. RESULTS: The dissection of the anterior intercavernous sinus, diaphragma sella, and arachnoid membrane allowed a wide surgical field of pre- and suprasellar areas and facilitated a safe removal of lesions without significant surgical complications in our cases. CONCLUSION: From the authors' limited experience, the advantages of this technique are as follows: 1) it can be easily applicable through a minor modification of the standard TSA, 2) excellent anatomical exposure of the structures located in the supradiaphragmatic suprasellar cistern, and 3) might be suitable to remove small lesions located in the presellar and adjacent to the pituitary stalk region.
Arachnoid ; Cranial Fossa, Anterior ; Craniotomy ; Humans ; Membranes ; Meningioma ; Pituitary Gland

To improve the surgical results of the removal of the pituitary tumors extending beyond the limit of the sella turcica, several modified transsphenoidal approachs have been proposed by many surgeons. A microanatomy of the sphenoid sinus, sellar, suprasellar and parasellar regions were studied in 50 formalin-fixed human cadaveric heads. Among them, microanatomical cadaveric dissections were performed in 5 specimens which were injected with colored silicone rubber. We aim to present a detailed microsurgical anatomy of structures surrounding the sella turcica. And also, the requisite microanatomical details necessary to extend the TSA to the medial compartment of the cavernous sinus and the supradiaphragmatic intradural space.
Cadaver ; Cavernous Sinus ; Head ; Humans ; Pituitary Neoplasms ; Sella Turcica ; Silicone Elastomers ; Sphenoid Sinus

A new technique of endoscope assisted anterior cervical foraminotomy was developed to improve the conventional microsurgical anterior cervical foraminotomy. Microsurgical anterior cervical foraminotomy provides direct anatomical decompression of the compressed nerve root by removing the spondylotic spur or disc fragment while preserving the functioning segment of the disc. The authors modified the anterior cervical foraminotomy using the MED TM(Microendoscopic discectomy) system to minimize the skin incision, and to achieve safe drilling and easy retraction. The uncinate process was drilled under endoscopic visualization through a tubular retractor. This technique has been applied to 13 patients with single level radiculopathy due to posterolateral osteophyte or soft disc herniation. The nerve roots were decompressed successfully under endoscopic control as in conventional microsurgical foraminotomy through a 2cm skin incision. Postoperatively, all patients showed improvements in their radiculopathic symptomatologies. Corresponding CT scans confirmed satisfactory anatomical decompression in all patients. This surgical technique has shown good clinical outcomes with fast recovery.
Decompression ; Endoscopes* ; Foraminotomy* ; Humans ; Osteophyte ; Radiculopathy ; Skin ; Tomography, X-Ray Computed

Authors report a ganglion cyst located in spinal canal. The ganglion cyst is soft and movable mass in connective tissue around peripheral joints or tendon sheath. It has been rarely reported in lumbar spine. Symptoms and signs are usually difficult to distinguish it from other etiologies of radicular pain. The extradurally located ganglion cyst at L4-5 level which caused back pain and sciatica was removed with partial hemilaminectomy. Radiological finding of cyst in MRI may be variable, according to the composition of the cyst. Based on our experience and pertinent literatue, a ganglion cyst should be considered in the differential diagnosis of radicular pain in the presence of degenerative changes of the lumbar spine.
Back Pain ; Connective Tissue ; Diagnosis, Differential ; Ganglion Cysts* ; Joints ; Magnetic Resonance Imaging ; Sciatica ; Spinal Canal ; Spine* ; Tendons

The authors describe a case with an uneventful outcome following prolonged temporary arterial occlusion during surgery for an aneurysm of the dorsal internal carotid artery(ICA). It has been shown that in various situations arising during aneurysm surgery, temporary arterial occlusion effectively prevents a premature rupture. It is not possible, however, to predict beforehand what the permissible occlusion time for any individual patient might be. During dissection of a blister aneurysm of the ICA, premature rupture developed, and intermittent temporary occlusion of the ICA, which lasted for about 150 minutes, was then undertaken. In addition, intraoperative neuroprotection was effected in several ways, including intermittent reperfusion and the administration of mannitol, thiopental sodium and steroid. There were no significant postoperative neurological deficits. To the authors' knowledge, this report is unusual in that it documents prolonged temporary occlusion without major neurological sequelae in intracranial aneurysm surgery. Permissible temporary occlusion time and neuroprotective methods are also discussed.
Aneurysm* ; Blister ; Carotid Artery, Internal* ; Humans ; Intracranial Aneurysm ; Mannitol ; Reperfusion ; Rupture ; Thiopental

We report three cases of patient with pleomorphic xanthoastrocytoma(PXA). PXA is a clinicopathologically distinct variant of cerebral astrocytoma which is a low-grade leptomeningeal glioma affecting under the age of 30 years. This tumor has a favorable prognosis, but histological and neuroradiological findings suggest malignant brain tumor. Occasionally these may be confused with malignant gliomas. Clinical features from our three patients were manifestation of increased intracranial pressure and all cases were under the age of 30 years and females. Two patients had superficial location in the right frontal and left temporal respectively, but remaining one(case 2) which was associated with arteriovenous malformation in the left frontal region was in the right lateral ventricle. The intraoperative histological evidence by frozen biopsy suggested glioblastoma or anaplastic astrocytoma in all cases which confirmed to be PXA by postoperative histological examination. Two cases which had been resected subtotally were followed by cranial irradiation without therapeutic efficacy. Optimal management of PXA is primary surgical resection to reduce recurrence of tumor and to secure long-term survival. Therefore, differentiation of PXA from malignant brain tumors and intraoperative diagnosis of PXA is imperative to treat PXA effectively.
Arteriovenous Malformations ; Astrocytoma ; Biopsy ; Brain Neoplasms ; Cranial Irradiation ; Diagnosis ; Female ; Glioblastoma ; Glioma ; Humans ; Intracranial Pressure ; Lateral Ventricles ; Prognosis ; Recurrence

The authors report a case of rostral mesencephalic dysfunction due to obstructive hydrocephalus secondary to periaqueductal tumor who suffered multiple shunt failures and shunt revision. This patient presented with clinical syndromes, including akinetic mutism and diencephalic autonomic epilepsy. He had computed tomography(CT) and magnetic resonance(MR) findings of dilatation of ventricular system with periaqueductal tumor. The anatomical substrates of clinical findings are reviewed. A discussion of the probable mechanism proposes that dilatation of 3rd ventricle and rostral aqueduct sufficiently explains the entire syndrome.
Akinetic Mutism ; Dilatation ; Epilepsy ; Humans ; Hydrocephalus* ; Mesencephalon*

The authors analysed 140 cases of subdural hygroma developed after head injury and various neurosurgical operations and was treated at Hanyang university hospital from 1983 to 1989. The results were analysed and summarized as follows. 1) The peak incidence was the age over 50 and under 10. 2) 104 cases(74.4%) were bilateral frontotemporoparietal lesions. 3) Causes were head injury(121 cases), operation for intracranial aneurysms(5 cases), ventriculoperitoneal shunt(5 cases), traumatic(2 cases), external ventricular drainage(1 case). 4) Change in mental status without focal sign of brain damage was presenting symptom. 5) Operation was underwent if 63 cases and the reaccumulation rate was high (26.8%) after trephination but outcome was favorable. 6) Mortality rate in traumatic subdural hygroma was low(5.8%) because brain CT could detect subdural hygroma easily in early stage.
Brain ; Craniocerebral Trauma ; Head ; Incidence ; Mortality ; Subdural Effusion* ; Trephining

The authors report a case of far lateral disc herniation at L4-5 found one year after percutaneous laser lumbar discectomy. The patient was found to be suffering from new-onset right lumbar radiculopathy 6 months after his first operation, and post operative lumbar MRI confirmed a far lateral extraforaminal disc herniation at L4-5, with compression of the nerve. This corresponded to the nucleotomy site of the probe. The patient underwent surgery employng the combined paraspinal intertransverse and interlaminar approach, and his symptoms were relieved. This case emphasizes the importance of removing nuclear material, and shows that remaining material can herniate through a percutaneous discectomy window.
Diskectomy* ; Diskectomy, Percutaneous ; Humans ; Magnetic Resonance Imaging ; Radiculopathy