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Biomedical subjects

T Takemae

Publications and source records attributed to T Takemae.

At least 19 recordsLinked to original sources
PubMed2001

Is carotid reconstruction for advanced cancer in the neck a safe procedure?

Head and neck surgeons hesitate to resect the carotid artery because of the postoperative risk of neurologic sequelae. On the other hand, there is no curative therapeutic option for head and neck cancer involving the carotid artery, except for complete tumor removal. A retrospective review of all published articles in the English literature dealing with carotid reconstruction for head and neck cancer from 1987 to 1998 was performed. There were only 11 articles, including our series, that reported outcomes of this procedure. Among the 148 patients of this series, major neuromorbidity was 4.7%, and mortality occurred in 6.8% of the patients. Combined major neuromorbidity and mortality was 10.1%. Because total removal of the advanced cancer is the only therapy that can offer the patients a chance for cure, head and neck surgeons should aggressively perform carotid resection and reconstruction.

Carotid Arteries↗
PubMed2001

Simulation studies of the ischemic vulnerability of the subendocardium.

Changes in the subendo-subepi flow ratio were studied by using a simple electronic circuit model of the coronary vessel consisting of a resistor, capacitor and field effect transistor in order to provide a better understanding of the ischemic vulnerability of the subendocardium. The simulated subendo-subepi flow ratio was found to be approximately 1.2 under normal condition. Changes in the flow ratio were observed while varying the main arterial resistance, mean arterial pressure and intramyocardial pressure individually. The mean flow in the subendocardium was found to decrease at a rate faster than that in the subepicardium with the increase in the septal arterial resistance and the intramyocardial pressure. The same tendency was also observed while the arterial pressure was lowered. This decrease in the mean subendocardial flow is considered to be the effect of higher end-systolic resistance in the subendocardial venule compared to that in the subepicardial venule. These results would be helpful in understanding the vulnerability of the subendocardium to ischemia and in providing clinical treatment to patients with that disease.

Animals↗
PubMed1995

The safe and complete removal of a carotid body tumor with elements suggestive of a malignant potential by employing an intraluminal shunt: report of a case.

The carotid body tumor is a relatively rare neoplasm arising from the intercarotid paraganglions. We report herein the case of a patient with a Shamblin group 2 type carotid body tumor for which safe and successful removal was facilitated by the insertion of an intraluminal shunt. The patient was a 54-year-old man who presented with a spherical elastic mass, 4.8 x 3.7 cm in size, on the right anterior aspect of his neck, which was diagnosed as a carotid body tumor by diagnostic imaging. Because the tumor was suspected to be malignant based on the operative findings, which included invasive adhesion to the carotid artery, an intraluminal shunt was inserted, allowing for safe and complete removal. Histologically, this tumor showed malignant potential with sporadic mitoses and incomplete capsular invasion. Thus, it is recommended that an intraluminal shunt be employed for the removal of a carotid body tumor when it is found to be tightly adherent to the carotid artery during the operation.

Anastomosis, Surgical↗
PubMed1995

Total resection of torcular herophili hemangiopericytoma with radial artery graft: case report.

A case of recurrent hemangiopericytoma involving the torcular herophili is reported, with special reference to the reconstruction of the straight sinus with a radial artery graft. In preoperative investigations, the tumor was found invading the straight and transverse sinuses. The involved occipital superior sagittal sinus had been removed in the previous surgery. A collateral bypass was observed from the superior sagittal sinus to the straight sinus, and the veins of Rosenthal were not opacified, suggesting poor venous drainage from the deep venous system to the cavernous sinus. We considered it necessary to reconstruct the straight and right transverse sinuses to achieve total removal of the tumor. The affected sinuses were removed and were successfully reconstructed with a radial artery interposition graft between the straight and right transverse sinus. The postoperative course was good, and the bypass was patent on the postoperative angiogram. The details of the operative technique are described.

Adult↗
PubMed1993

Intraoperative computed tomographic scanning during transsphenoidal surgery: technical note.

Intraoperative computed tomographic scanning during transsphenoidal surgery on pituitary lesions is performed and evaluated. A computed tomographic scanner system exclusively developed for the operating room is used for this purpose during transsphenoidal surgery. Ten consecutive patients with pituitary lesions underwent operations by this method, which used a combination of an ordinary fluoroscopy unit and the computed tomographic scanner.

Adenoma↗
PubMed1993

Perinidal hypervascular network on immediate postoperative angiogram after removal of large arteriovenous malformations located distant from the arterial circle of Willis.

Unexplained intraoperative or postoperative hemorrhage occurs in certain cases in the surgery of large arteriovenous malformations (AVMs), which are defined as those with maximal diameter of the nidus larger than 5 cm. Immediate postoperative angiograms were evaluated with reference to whether such hemorrhage could be predicted. Immediate postoperative angiograms were taken in 12 patients with large AVMs on the day after the operation during which the AVM was removed. In five of six AVMs located in the distal cerebral hemisphere, a hypervascular network was seen in the vicinity of the removed nidus on the immediate postoperative angiogram. The unexplained hemorrhage occurred in four of the five cases with the hypervascular network. In the remaining six patients with AVMs, the hypervascular network was not observed and they did not develop hemorrhage; the AVMs were located either close to the arterial circle of Willis or in the cerebellum. We believe that the hypervascular network seen on the immediate postoperative angiogram after the removal of a large distal AVM is an important sign predicting the likelihood of unexplained intraoperative and postoperative hemorrhage development. We call this perinidal hypervascular network "modja-modja vessels" because it resembles shaggy hair. The mechanism of its appearance and the pathogenesis of the unexplained intraoperative and postoperative hemorrhage are discussed.

Adolescent↗
PubMed1993

[CT guided transsphenoidal surgery: report of nine cases].

We have developed a Computed Tomography system for use in the operating room and applied this CT system to intraoperative monitoring during transsphenoidal surgery. This system includes Toshiba TCT-300 CT system, mobile CT scanner gantry, digitally controlled operating table and head fixation system. Between June 1989 and Dec. 1989, CT guided transsphenoidal surgery was carried out in 9 cases in our department. The suprasellar masses were visualized directly during transphenoidal surgery and were removed safely and efficiently. Under this CT monitoring system the surgeon can obtain accurate information about the location and volume of residual tumor as well as about the important surrounding deeper structure. Another advantage of this system is that the digitally controlled operating table makes it possible to keep the patient in a head-up position, which lessens oozing from the parasellar region during transsphenoidal surgery. We believe the best application of this method is that for pituitary tumor with moderate suprasellar extension. Nine cases were reported in this paper which were operated on using this system. To our knowledge, this is the first report of use of intraoperative CT monitoring during transsphenoidal surgery.

Adenoma↗
PubMed1992

Multiple spinal neurinomas presenting visual disturbance as the initial symptom: case report.

A case of multiple spinal neurinomas with visual disturbance is reported. A 63-year-old man was admitted with a complaint of progressive visual disturbance due to papilledema without spinal symptoms and signs. The neuroimaging studies demonstrated communicating hydrocephalus and two mass lesions in the cauda equina. Both tumors were found to be neurinomas. Intracranial hypertension secondary to spinal tumors is unusual, and multiple spinal neurinomas are rare. In the patient without spinal symptoms and signs, it is difficult to make a diagnosis of spinal tumor. Importance of checking for a spinal cord lesion by magnetic resonance imaging in such a case is stressed.

Diagnosis, Differential↗
PubMed1992

Introduction of high definition television system to neurosurgical documentation.

The high definition television (HDTV) system is introduced to microneurosurgery. Five cases with intracranial lesions: three cerebral aneurysms (giant aneurysms of the anterior communicating artery and internal carotid artery, aneurysm of the basilar artery), one acoustic neurinoma and one skull base meningioma, were operated on under the microscope using the HDTV system. The surgical procedures of each case were relayed and recorded by the system. In two of the five cases, we used two sets of HDTV system to produce stereoscopic projection. The HDTV system provided us with images of superior quality with a distinctly greater resolution than ordinary video systems.

Adult↗
PubMed1992

Effect of AT877 on cerebral vasospasm after aneurysmal subarachnoid hemorrhage. Results of a prospective placebo-controlled double-blind trial.

With the cooperation of 60 neurosurgical centers in Japan, a prospective randomized placebo-controlled double-blind trial of a new calcium antagonist AT877 (hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine hydrochloride, or fasudil hydrochloride) was undertaken to determine the drug's effect on delayed cerebral vasospasm in patients with a ruptured cerebral aneurysm. A total of 276 patients, who underwent surgery within 3 days after subarachnoid hemorrhage (SAH) of Hunt and Hess Grades I to IV, were entered into the study. Nine patients were excluded because of protocol violation. The remaining 267 patients received either 30 mg AT877 or a placebo (saline) by intravenous injection over 30 minutes, three times a day for 14 days following surgery. Demographic and clinical data were well matched between the two groups. It was found that AT877 reduced angiographically demonstrable vasospasm by 38% (from 61% in the placebo group to 38% in the AT877 group, p = 0.0023), low-density regions on computerized tomography associated with vasospasm by 58% (from 38% to 16%, p = 0.0013), and symptomatic vasospasm by 30% (from 50% to 35%, p = 0.0247). Furthermore, AT877 reduced the number of patients with a poor clinical outcome associated with vasospasm (moderate disability or worse on the Glasgow Outcome Scale at 1 month after SAH) by 54% (from 26% to 12%, p = 0.0152). There were no serious adverse events reported in the AT877 group. This is the first report of a placebo-controlled double-blind trial that has demonstrated a significant reduction in angiographically revealed vasospasm by intravenous drug therapy.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1992

Giant thrombosed vertebral artery aneurysm managed with extracranial-intracranial bypass surgery and aneurysmectomy. Case report.

A case is presented of a left giant thrombosed vertebral artery aneurysm in a 46-year-old man. The giant thrombosed aneurysm was successfully resected with trapping of the affected artery after right external carotid artery-posterior cerebral artery bypass surgery using a radial arterial graft. The clinical course is reported, and the details of the operative approach and techniques are discussed.

Humans↗
PubMed1991

Development of the operating computerized tomographic scanner system for neurosurgery.

A computerized tomographic (CT) scanner system for intraoperative imaging is presented. The system consists of the following: 1) CT scanner with a mobile gantry, 2) digitally controlled operating table with central processing unit (CPU) and encoder unit; the table can be controlled by the scanner computer as accurately as the scanner bed, and 3) exclusively designed head fixation devices. It allows us to scan the patient on the operating table in the operating room pre-operatively, intra-operatively and immediately after surgery.

Computer Systems↗
PubMed1990

Dose escalation trial of a novel calcium antagonist, AT877, in patients with aneurysmal subarachnoid haemorrhage.

The initial dose-escalating clinical trial of a novel calcium antagonist, AT877, in patients with aneurysmal subarachnoid haemorrhage is reported. AT877 is characterized by its strong spasmolytic activity, its inhibition of intracellular calcium ion activity, and the inhibition of several protein kinases. A total of 113 patients (Hunt and Hess grades I to IV) who had undergone surgery within 3 days of aneurysmal rupture entered the study. Patients were divided into 5 groups according to the total daily dose of AT877: I: 20 mg; II: 40 mg; III: 60 mg; IV: 90 mg; and V: 120-180 mg. AT877 was given by intravenous infusion over 30 min two or three times a day for 14 days after surgery. Although AT877 did not completely abolish angiographic vasospasm, severe vasospasm was seen less frequently in patients given higher doses. Vasospasm was the cause of a poor clinical outcome (Glasgow outcome scale rating 3 or greater) in 19%, 7%, 9%, 8%, and 6% of the patients in groups I to V, respectively. The results indicated a favourable clinical effect of AT877 at doses above 40 mg per day. Only mild hypotension was seen, even when 60 mg of AT877 was infused over 30 min. AT877 appears to be effective in patients with subarachnoid haemorrhage. Part of its effect may be attributable to protection of the brain from ischaemic insults due to chronic cerebral vasospasm. However, the drug still needs to be evaluated in a placebo-controlled double-blind trial (which is currently being carried out).

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1990

Normovolaemic induced hypertension therapy for cerebral vasospasm after subarachnoid haemorrhage.

We showed that normovolaemic induced hypertension therapy was effective in reducing ischaemic symptoms attributed to cerebral vasospasm in 41 patients after subarachnoid haemorrhage. By inducing hypertension to 25% to 50% above normal systolic arterial blood pressure, we observed that in 17 of 24 cases (71%) neurological deficits improved. In four cases of haemorrhagic infarction, the blood pressure rose to over 50% of systolic arterial pressure, and a low density area was confirmed on computerized tomography (CT) scan prior to vasospasm. Induced hypertension was therefore not considered when a low density area was revealed on CT scan. Restriction of fluid input is usually a factor in producing hypovolaemia after a neurosurgical operation. Intravascular volume expansion has been reported effective in reversing ischaemic deficits. However, according to Poiseuille's equation, increasing blood volume to a state of hypervolaemia can not enhance flow. The cerebral blood flow (CBF) was raised by increasing perfusion pressure, reducing viscosity, or increasing blood vessel diameter. Intravascular volume expansion elevates not only systemic arterial pressure, but also pulmonary artery wedge pressure over 18 mmHg and cardiac index over 2.2. Since pulmonary oedema and congestive heart failure may develop, one should monitor haemodynamic parameters with the Swan-Ganz catheter as a preventive measure. We emphasize that normovolaemic induced hypertension, maintaining haemodynamics subset 1 of the comparable haemodynamic subsets, is effective in raising perfusion pressure of CBF.

Adult↗
PubMed1990

New tetrapolar circuit method using magnetic field for measurement of local impedance change in biological substances.

A new tetrapolar circuit method using a magnetic field is proposed to measure the local electric impedance change in living tissue. Based on this method, we designed an apparatus which can detect impedance changes in closely-situated two parts of living tissue, simultaneously and independently. Using this apparatus, we showed the effectiveness of the proposed method by an in vitro experiment and by an in vivo measurement of pulsatile waveforms in the forearm arteries. The detection sensitivity for a local impedance change was confirmed to be higher than that of the conventional tetrapolar method. Pulsatile impedance waveforms measured in the radial and the ulnar parts of the forearm were consistent with those estimated from the anatomical structure.

Arteries↗
PubMed1990

[Evaluation of FOY therapy for DIC or pre-DIC associated with neurosurgical disease].

Disseminated intravascular coagulation (DIC) is not a rare phenomenon in the neurosurgical field. We investigated the therapeutic effect of [Ethyl p - (6-guanidinohexanoyloxy) benzoate] methanesulfonate (FOY) for DIC or Pre-DIC states associated with neurosurgical disorders. During the previous three and half years, a total of 52 cases have been admitted to Shinshu University Hospital and its affiliated hospitals with DIC or Pre-DIC states due to brain disorders (group A) associated with head injuries (19 cases), subarachnoid hemorrhages caused by ruptured aneurysm (12 cases), intracranial hemorrhages and infarctions (5 cases), arteriovenous malformations (2 cases) and spinal cord injury (1 case), and with those states due to brain and another disorders (group B) associated with infections (7 cases), shocks (2 cases) and intoxications by drugs (2 cases). FOY was administered continuously for all patients. Clinical manifestations and laboratory data were analyzed statistically. Platelet count improved from during the 7th to the 10th day after starting FOY. It improved significantly in cases with a high DIC score and the improvement was not influenced by platelet transfusion. FDP, fibrinogen, prothrombin time and antithrombin-III also improved. DIC score remarkably improved in cases with an initial high DIC score. Hemorrhagic symptoms were recognized in 19 cases before administration of FOY and 14 of them (74%) improved after the treatment. Dysfunction of organs was recognized in 28 cases, of which 5 cases (18%) improved. Twenty-nine of 52 cases (56%) were still alive. Only two patients died due to DIC. There were no side effects associated with administration of FOY.(ABSTRACT TRUNCATED AT 250 WORDS)

Anticoagulants↗
PubMed1989

Subdural fluid collections following transcortical approach to intra- or paraventricular tumours.

Subdural fluid collections appeared in 15 cases (39%) after removal of 38 intra- and paraventricular tumours in the third or lateral ventricle through 18 frontal and 20 parietal transcortical approaches. Transient fluid collections which disappeared within 2 weeks occurred in 6 cases (16%) and persistent ones in 9 cases (24%). Four of the 9 cases (11%) of collections required surgical treatment because of positive clinical signs and symptoms. Two cases had expansive fluid collections and the other two contained subdural haematomas at surgery. The risk factors likely to contribute to a persistent collection were preoperative ventriculomegaly (frontal horn index greater than 0.38) and a frontal transcortical approach. A symptomatic collection should be considered as a potential complication of the transcortical approach to intraventricular tumours and some methods should be devised to prevent it when intra- or paraventricular tumours with ventriculomegaly are removed.

Adolescent↗