A combined trans-petrosal approach which includes some degree of anterior petrosectomy and presigmoid posterior petrosectomy is quite an effective procedure for petroclival lesions, offering a wide and shallow surgical field. Several petrosal approach variations have been reported by master skull base surgeons and a detailed anatomy of the temporal bone has been obtained by cadaveric studies. These achievements enhanced the surgical safety and standardization of the procedure. But there still remain some critical risks in the procedure such as CSF leakage, sigmoid sinus injury and damaging the facial and cochlea nerves at petrosectomy. In this report, tips for the procedure including the way to harvest the fascia-pericranial flap to prevent CSF leakage, to expose sigmoid sinus safely, to perform safe petrosectomy and to resect the petroclival tumors caring critical vascular and nerve structures, will be minutely presented. A fascia-pericranial flap with a pedicle of sternocleid mastoid muscle has completely prevented CSF leakage and the following infections. Dissecting the sinus wall at an antegrade direction has enabled the safe and quick exposure of the sigmoid sinus. Both the mastoid antrum and endlymphatic sac are crucial landmarks for detecting the semi-circular canals. Opening Meckel's cave encourages large transposition of the trigeminal nerve which enlarges the exposure of the tumor at the area between the trigeminal and facial-acoustic nerve band. Surgical results of the combined transpetrosal approach have been satisfactorily improved by the accumulated modifications of the procedure.

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We described the microsurgical anatomy of the lateral part of the foramen magnum and the transcondylar fossa approach (TCFA). The TCFA provides a wide and shallow operative field in the lateral part of the medulla oblongata at the level of the jugular foramen. Furthermore, wide dissection of the unilateral cerebello-medullary fissure is necessary to retract the cerebellum safely and manage the lesion in the wide operative field.

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The posterior interhemispheric approach (occipital transtentorial approach: OTA) is a useful approach to obtain supra- and infra-tentorial wide operative fields including the splenium, pineal region, quadrigeminal cistern and anterosuperior surface of the cerebellum. Lesions with a downward extension are very suitable for OTA because of its downward trajectory, but lateral lesions are difficult to expose with OTA. For pineal lesions, the Galenic venous complex obstructs the approach route and the anterosuperior part of such lesions is slightly difficult to observe. The occipital lobe and tentorial sinus venous systems are explained as they make up the important microsurgical anatomy for OTA. A comparison between OTA and the infratentorial supracerebellar approach is also discussed.

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The infratemporal fossa is located below the middle cranial fossa and behind the mandible. Since the mandibular joint and the facial nerve lie in the lateral portion, a simple lateral approach is difficult. For large tumors, an infratemporal fossa approach through the posterior temporal region can be used, though drilling of the mastoid process, sacrifice of the external and middle ear and the mandibular joint are required. For more midline-located lesions, a mandibular swing approach can also be used. This approach, however, needs a midline facial incision. To preserve function and avoid the facial incision, a subtemporal-preauricular infratemporal fossa approach is more useful. Without mandibular joint resection, this approach allows access to a wider region of the infratemporal fossa with acceptable cosmetic results and functional deficits. For a more limited lesion, a simple cranial or cervical approach may be used. Though the infratemporal fossa has not been familiar for neurosurgeons, further anatomical understanding and collaboration with head and neck surgeons would improve the surgical outcome of patients harboring infratemporal lesion.

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At present, the management of carotid artery (CA) stenosis depends largely on the degree of stenosis. CA plaque imaging is a modality, which assesses the nature of CA plaques objectively and less invasively, that has developed remarkably in recent years. The use of CA plaque imaging in the management of CA stenosis not only reveals the degree of stenosis but it can make the selection of treatment more appropriate by taking the plaque character into consideration. In this manuscript, we introduce ultrasound, intravascular ultrasound, angiography, magnetic resonance imaging (MRI), positron emission tomography (PET) and computed tomography (CT) and describe the present situation and new perspectives of CA plaque imaging.

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Although chronic subdural hematoma (CSDH) is well known as a curable condition, it also has a significant recurrence rate. To identify risk factors for recurrence, we compared the clinical features in two groups of patients with or without recurrence. The present study included 172 adult patients who had underwent one burr-hole and closed-system drainage between April 2007 and January 2010. Of these 23 cases (13.4%) experienced recurrence after surgery. The factors analyzed were: 1) patient background including, gender, age, history of drinking, diabetes, and the use of antiplatelet or anticoagulant medications, and a history of head injury, 2) clinical symptoms, including initial neurologic symptoms, and computed tomography findings such as hematoma thickness, midline-shift, and density of the hematoma 3) factors related to surgery such as duration from trauma to surgery and operation method and 4) the recurrence rate. The results of this study showed that a short duration from trauma to surgery and the absence of traumatic history were recurrence factors for CSDH after burr-hole surgery. These results suggest that any cases with these risk factors should be closely observed after burr hole surgery.

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A 61-year-old man with a history of esophageal carcinoma operated one year before was admitted to our hospital because of left hemiparesis including face. MRI revealed a cystic mass with a solid nodule in the right parietal lobe. The cyst was hypointense on T1-wighted images of MRI, with markedly enhancing rim after Gd injection. On T2-weighted images, the cyst was hyperintense, and the solid portion appeared to be heterogeneous. Based on the patient's past history, a metastatic brain tumor from esophageal carcinoma was suspected. A parietal craniotomy was performed, and the tumor was completely excised macroscopically. Histological diagnosis was a moderately differentiated squamous cell carcinoma, confirming our preliminary diagnosis. The patient had a good postoperative course, with complete resolution of his symptoms. Brain metastases from esophageal carcinoma are relatively rare, and little information is available on the clinical course and radiological findings. Here we report clinical and radiological features of brain metastasis from esophageal carcinoma focusing on MRI findings, with review of the literature.

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We present a case of huge invasive prolactinoma that was uncontrollable with medication. A 53-year-old woman was admitted to our hospital with generalized convulsion. Brain magnetic resonance imaging (MRI) revealed a huge sellar and suprasellar mass with compression of the frontal lobe and extension into the right cavernous sinus. The maximum tumor diameter was approximately 5.8cm and serum prolactin (PRL) level was raised to 3,459ng/ml. The dopamine agonist cabergoline was administered as a first line treatment. Maximum oral administration of cabergoline was insufficient to normalize serum PRL levels. Moreover, the tumor increased in size. To reduce tumor volume we performed a two-staged operation involving subtotal removal with a craniotomy followed by a transsphenoidal surgery. After tumor volume reduction, cabergoline became effective enough to normalize serum PRL. Histological examination revealed mild nuclear atypia, focal hypercellularity, and increased MIB-1 labeling index (11%). In summary, surgical volume reduction of the tumor was a key factor allowing control of serum PRL with cabergoline administration in our case. The limitations of cabergoline in some cases of huge prolactinoma should be recognized, and combining surgical treatment should be considered.

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