New microsurgical technique for intraparenchymal lesions of the brain: transcylinder approach.

BACKGROUND: Although various minimally invasive approaches, including endoscopic, stereotaxic, and ultrasound-guided surgery, have been introduced to minimize damage to healthy brain tissue, the microsurgical technique has retained a significant role in contemporary neurosurgery. A new microsurgical approach to intraparenchymal brain lesions, namely, the transcylinder approach, was developed to realize both minimal surgical access and sufficient microsurgical technique. METHOD: A 0.1-mm transparent polyester film was used to create a cylindrical surgical route. The film was rolled into a thin stick and used to penetrate the brain, and a computer-aided navigation system was used from inside the stick to access the lesion accurately. After the stick gained access to the lesion, it was dilated to 2 cm, and this diameter was maintained during surgery. FINDINGS: The transcylinder approach was used in 11 cases, including intraparenchymal tumours and haematomas, and the usual microsurgical procedure was performed without difficulty. The film avoided unnecessary enlargement of the surgical field and minimized injury to the brain. Intra-operative ultrasonography also can be used to identify the lesion through the cylinder because the polyester film does not reflect the ultrasound beam. The surgical route was observed to recover to almost the same size as the initial cortical incision after removal of the cylinder. CONCLUSIONS: The transcylinder approach could be advantageous for removing tumours or haematomas in the intraventricular or intraparenchymal regions. By avoiding unnecessary retraction, it significantly reduces the risk of injury to surrounding brain tissue while facilitating precise microsurgical technique. The accuracy of this minimally invasive technique can be enhanced when used in conjunction with frameless stereotaxy and intra-operative ultrasound guidance.

Surgical treatment of a massive chondrosarcoma in the skull base associated with Maffucci's syndrome: a case report.

BACKGROUND: A successfully treated massive chondrosarcoma in the skull base associated with Maffucci's syndrome is presented. The purpose of this report is to discuss the surgical approach to the tumor and reconstruction of the skull base. CASE DESCRIPTION: A 36-year-old woman who had a history of multiple enchondromas and subcutaneous hemangiomas presented with decreased right visual acuity and left papilledema. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated a mass in the skull base. The tumor occupied the nasal and paranasal cavities, and extended to the anterior, middle, and posterior intracranial spaces. The midline skull base structures and the left middle cranial base were destroyed. Using a combined anterior craniofacial and left orbitozygomatic approach, the tumor was totally resected. The large skull base defect was reconstructed with a vascularized outer table parietal bone graft attached to a bipedicled temporoparietal galeal flap. The postoperative course was uneventful except for decreased left visual acuity, and temporary diplopia and facial hypesthesia. In 40 months of follow-up there was no recurrence. CONCLUSIONSA skull base approach should be selected to perform total resection of an extensive skull base tumor. The bipedicled temporoparietal galeal flap and vascularized calvarial bone was useful for simultaneous reconstruction.

Sarcomatous transformation of a prolactinoma associated with development of a fatal internal carotid artery pseudoaneurysm--case report.

A 21-year-old female with a 5-year history of prolactinoma was referred to our hospital because of cerebrospinal fluid leakage and meningitis immediately following a third transsphenoidal operation for a rapidly growing tumor. Histological examination of the tumor removed at the second transsphenoidal operation found atypical epithelial and sarcomatous components. Administration of bromocriptine, radiotherapy, and chemotherapy were initiated. Emergent craniotomy was required for rapid regrowth of the tumor. Histological examination found predominant sarcomatous components. Tumor growth was difficult to control. The patient died of subarachnoid hemorrhage due to rupture of a pseudoaneurysm involving the C1 portion of the right internal carotid artery. Pituitary adenoma rarely shows malignant transformation. In this case, prolactinoma underwent malignant change to sarcoma. Development of the pseudoaneurysm may have resulted from surgical manipulation, radiotherapy, or tumor invasion.

[Effect of cholesterol reducing therapy with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor on secondary prevention after myocardial infarction in Japanese patients].

Lowering the blood cholesterol level is a safe method to improve survival for primary and secondary prevention of coronary heart disease. However, there is no evidence for any effectiveness in Japanese. This study was designed to evaluate the effect of cholesterol lowering therapy with 3-hydroxy-3-methylglutaryl coenzyme A(HMG-CoA) reductase inhibitor on cardiac events(death and reinfarction) in Japanese patients after myocardial infarction. A total of 290 patients after myocardial infarction were studied retrospectively. The patients were divided into 2 groups with or without HMG-CoA reductase inhibitor therapy for lowering blood cholesterol levels. The cumulative cardiac events and percentage change of cholesterol levels[total cholesterol and low-density lipoprotein (LDL) cholesterol level] were compared between the 2 groups. HMG-CoA reductase inhibitor therapy lowered plasma cholesterol levels significantly (total cholesterol level--11 +/- 20%, LDL cholesterol level--23 +/- 26%) in patients with hypercholesterolemia, whereas there was no change(total cholesterol level 4.3 +/- 22%, LDL cholesterol level--7.2 +/- 24%) in patients without hypercholesterolemia. HMG-CoA reductase inhibitor therapy reduced cardiac events significantly compared in patients with hypercholesterolemia(p = 0.0008), but there was no benefit in patients without hypercholesterolemia. We suggest that treatment with HMG-CoA reductase inhibitor therapy for lowering cholesterol levels was effective for secondary prevention after myocardial infarction in Japanese patients with hypercholesterolemia.

Bypass surgery using a radial artery graft for bilateral extracranial carotid arteries occlusion.

A patient presenting with recurrent ischemic attacks was demonstrated to have complete occlusion of the right common and left internal carotid arteries. An external carotid angiogram showed a large left superficial temporal artery (STA) supplying both sides of the scalp. 123I-IMP single photon emission computed tomography (SPECT) revealed hypoperfusion of the both hemispheres, especially the left cerebral hemisphere. An extracranial-intracranial (EC-IC) bypass was performed using a radial artery graft interpositioned between the proximal part of the STA and the M2 segment, thus preserving blood flow to the scalp through the STA. Postoperative angiography after 1 year showed good circulation through the anastomosis, and 123I-IMP SPECT studies demonstrated increased cerebral perfusion. The patient improved clinically. The surgical technique is described below.

Management of the cavernous sinus in en bloc resections of malignant skull base tumors.

BACKGROUND: Cavernous sinus involvement represents the most difficult problem in en bloc resection of malignant skull base tumors. We developed three types of surgical procedures for manipulating the cavernous sinus to achieve en bloc resection of these tumors. METHODS: In a type 1 procedure, the cavernous sinus was dissected epidurally and retracted posteriorly. In a type 2 procedure, the anterolateral portion of the cavernous sinus was excised and the carotid artery preserved. In a type 3 procedure, the entire cavernous sinus including the carotid artery was resected. RESULTS: Of 25 malignant skull base tumors, type 1 procedures were used in 7, type 2 in 5, and type 3 in 3. For these 15 patients, 7 are in good condition without evidence of tumor recurrence, 2 are alive with tumor, 4 died of tumor recurrence, and 2 died of complications. Two-year survival rates were 54% for patients with a type 1 procedure, 100% for type 2, and 33% for type 3. CONCLUSIONS: Using our techniques, we could totally excise tumors impinging on the cavernous sinus. However, the advanced tumors requiring resection of the entire cavernous sinus with the carotid artery are associated with major morbidity and mortality.

Preoperative short-term administration of octreotide for facilitating transsphenoidal removal of invasive growth hormone-secreting macroadenomas.

The somatostatin analog octreotide was administered prior to transsphenoidal surgery in three patients with tumors that extended to the suprasellar space and one side of the cavernous sinus. Octreotide, 100 micrograms twice a day, was subcutaneously injected for 2 weeks. Octreotide administration reduced the serum growth hormone (GH) levels in these patients from 82 to 22 ng/ml, from 148 to 12 ng/ml, and from 129 to 9 ng/ml. The tumor size shrank by about 50%, and the suprasellar extension disappeared in two patients. The main tumor was sharply dissected from the normal pituitary gland at surgery. Intracavernous portions were removed using a curette. Postoperatively, GH levels were less than 5 ng/ml in two patients, and 8.5 ng/ml in one patient. Follow-up magnetic resonance imaging revealed a small residual tumor in one side of the cavernous sinus in all patients. Follow-up GH levels were less than 5 ng/ml in one patient, and less than 2 ng/ml in two patients treated with bromocriptine. Preoperative administration of octreotide for 2 weeks reduced tumor volume and allowed near-total surgical resection of invasive macroadenomas without compromising the treatment course. Residual tumor due to intracavernous extension can be managed with bromocriptine or gamma knife radiosurgery.

Intra-arterial infusion of fasudil hydrochloride for treating vasospasm following subarachnoid haemorrhage.

In this pilot study we treated cerebral vasospasm in patients with subarachnoid haemorrhage to assess intra-arterial fasudil hydrochloride. We analysed effects of intra-arterial infusion on angiographically evident cerebral vasospasm in 10 patients including 3 with symptoms of vasospasm. Over 10 to 30 min 15 to 60 mg was administered via the proximal internal carotid artery or vertebral artery following standard angiography, without superselective techniques. A total of 24 arterial territories (21 internal carotid, 3 vertebral) were treated. Angiographic improvement of vasospasm was demonstrated in 16 arterial territories (local dilation in 2, diffuse dilation in 14) in 9 patients. In 2 symptomatic patients, intra-arterial fasudil hydrochloride was associated with resolution of symptoms without sequelae. In the third symptomatic patient the benefit of fasudil hydrochloride was only temporary, and a large cerebral infarction occurred. All asymptomatic patients showed no progression of angiographic to symptomatic vasospasm after treatment with intra-arterial fasudil hydrochloride. No adverse effect was encountered.

Recovery of olfactory function after an anterior craniofacial approach.

We assessed recovery of olfactory function in five consecutive patients who underwent surgical resection of midline skull base tumors using an anterior craniofacial approach in which the cribriform plate was mobilized with the dura. Olfactory function was evaluated before and after surgery using an intravenous olfactory test with prosultiamine and also a standard olfactory acuity test. Before surgery, one patient showed anosmia attributable to obstruction of the nasal cavity and olfactory cleft, and four patients showed normal olfactory function. After surgery, one patient was irreversibly anosmic, probably because of intradural dissection of the olfactory tracts. The other four patients, including the patient showing anosmia preoperatively, reported subjective recovery of olfaction 3 to 8 weeks after surgery. Intravenous and standard olfactory acuity tests indicated recovery of olfaction to the normal range in three patients and decreased olfactory function in one. With careful preservation of the olfactory system and of the integrity of the nasal cavity, olfactory function was found to recover after skull base resections via the anterior craniofacial approach.

Primary Ewing's sarcoma of the skull base with intracerebral extension--case report.

A 32-year-old female presented with an uncommon primary Ewing's sarcoma of the skull involving the middle cranial fossa with an extremely unusual extension into the cerebral parenchyma. She was treated with surgical excision, irradiation, and chemotherapy. Two years after surgery she demonstrated no evidence of local recurrence or distant metastasis. Ewing's sarcoma of the skull may achieve a better survival rate under adequate management than this lesion in other sites.