Kotoo Meguro

Repair of a tear at the base of a blister-like aneurysm with suturing and an encircling clip : technical note

OBJECTIVE An aneurysm can produce large defects in the parent vessel if the aneurysm tears at the neck of the vessel. The authors present a technique to repair a tear at the base of a blister-like aneurysm encountered during microsurgical clipping of an anterior wall aneurysm of the internal carotid artery. METHODS The repair technique involved suturing and covering the aneurysm with an encircling aneurysm clip. A large tear had destroyed the vessel’s tubular structure, and repair was not sufficient using an encircling clip alone. Two microsuture stitches were placed on the tear, so that a split artery re-formed a tubular structure. The lesion was then covered with Surgicel (Ethicon, Inc., Somerville, NJ) and fibrin glue. When the Surgicel and fibrin glue were applied, the temporary clip on the distal internal carotid artery was removed for a moment, allowing retrograde blood flow to provide the counterforce necessary to maintain the vessel’s tubular structure. An encircling clip was then applied to cover the entire circumference of the lesion. RESULTS This method required only a short occlusion time for arterial repair, thus helping avoid ischemic complications. The patient awoke with transient hemiparesis, but recovery was prompt. CONCLUSION This technique is useful for repairing an aneurysmal tear at its base, especially if the tear is large.

Suprasellar ectopic pituitary adenoma : case report and review of the literature

The occurrence of a totally suprasellar ectopic pituitary adenoma in a 71-year-old man is described. The tumor was attached to the pituitary stalk, extending upward toward the third ventricle. No intrasellar lesion was observed. Histological examination revealed a pituitary adenoma with large numbers of eosinophilic cells with moderate nuclear polymorphism and rare mitosis. Immunohistochemical staining revealed that the tumor cells were strongly positive for anti-adrenocorticotropic hormone antibody. A review of five previously reported intracranial ectopic pituitary adenomas revealed that two were silent corticotropic tumors and two occurred with Cushings syndrome.

Endothelin-1 concentration increases in the cerebrospinal fluid in cerebral vasospasm caused by subarachnoid hemorrhage.

BACKGROUND Endothelin-1 (ET-1) was originally identified as a potent vasoconstrictor peptide. Numerous reports have suggested its roles in various disorders. Although there is a great deal of evidence establishing the relationship between ET-1 and cerebral vasospasm in animals, this relationship still remains to be clarified in humans. METHODS The concentration of ET-1 in cerebrospinal fluid (CSF) was measured by radioimmunoassay in 23 subarachnoid hemorrhage patients. CSF samples were collected every 10 days after surgery from the cisternal drainage tube. RESULTS Initial concentrations of ET-1 in the CSF collected the first day after operation were all increased compared with the control CSF. In seven of the eight vasospasm patients, the concentrations of ET-1 had increased before the observation of vasospasm and then decreased before the disappearance of the vasospasm. In 13 out of the 15 patients without vasospasm, the concentrations of ET-1 in CSF decreased with time. CONCLUSION We confirmed that the concentration of ET-1 in CSF increased before the onset of cerebral vasospasm caused by subarachnoid hemorrhage. The ET-1 concentration in the CSF could be a useful marker to detect cerebral vasospasm after subarachnoid hemorrhage.

Embolization of a ruptured aneurysm of the distal anterior inferior cerebellar artery: case report and review of the literature.

BACKGROUND Aneurysms of the distal anterior inferior cerebellar artery (AICA) are rare and almost all of them have been treated surgically, by wrapping or trapping, in the previous literature. Most cases of aneurysms associated with the auditory artery resulted in a hearing disturbance from the surgical procedure, although aneurysms far from the auditory artery had no deficit from trapping. METHODS An 81-year-old woman presented with a ruptured aneurysm of the distal AICA. We planned a delayed treatment with intravascular embolization because of her advanced age and poor clinical status. Embolization of the distal anterior inferior cerebellar artery using detachable coils remote from the auditory artery was successful. RESULTS Magnetic resonance imaging after embolization demonstrated no remaining lesion. The patient has been through rehabilitation and has gradually improved. CONCLUSION Intravascular treatment of distal AICA aneurysms remote from the auditory artery may be safer and simpler than surgical treatment.

Differentiation of mechanism and prognosis of traumatic brain stem lesions detected by magnetic resonance imaging in the acute stage

We retrospectively evaluated the MRI from 17 patients with primary brain stem injury obtained in the acute stage. Clinical and radiological findings were analyzed in these 17 patients. T2-weighted imaging proved to be most sensitive and specific for the diagnosis of primary brain stem injury. We found two patterns of brain stem injury. The good prognosis group showed ventral brain stem lesions or dorsal superficial brain stem lesions. On the other hand the poor prognosis group showed deep dorsal brain stem lesions. These acute stage findings are seen only temporally in many cases so that it is most important to examine MRI findings in the acute stage to evaluate the prognosis of the patient. MRI was valuable in predicting the outcome. The possible mechanism of brain stem injury in patients with head injury is briefly discussed.

Synchrotron-based intra-venous K-edge digital subtraction angiography in a pig model: A feasibility study

BACKGROUND K-edge digital subtraction angiography (KEDSA) combined with the tunability of synchrotron beam yields an imaging technique that is highly sensitive to low concentrations of contrast agents. Thus, contrast agent can be administered intravenously, obviating the need for insertion of a guided catheter to deliver a bolus of contrast agent close to the target tissue. With the high-resolution detectors used at synchrotron facilities, images can be acquired at high spatial resolution. Thus, the KEDSA appears particularly suited for studies of neurovascular pathology in animal models, where the vascular diameters are significantly smaller than in human patients. MATERIALS AND METHODS This feasibility study was designed to test the suitability of KEDSA after intravenous injection of iodine-based contrast agent for use in a pig model. Four adult male pigs were used for our experiments. Neurovascular angiographic images were acquired using KEDSA with a solid state Germanium (Ge) detector at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. RESULTS After intravenous injection of 0.9 ml/kg iodinated contrast agent (Xenetix), the peak iodine concentrations in the internal carotid and middle cerebral arteries reached 35 mg/ml. KEDSA images in radiography mode allowed the visualization of intracranial arteries of less than 1.5mm diameter.

Magnetic resonance imaging of spinal cord injury without radiologic abnormality

A 3-year-old girl with spinal cord injury without radiologic abnormality (SCIWORA) is reported. Magnetic resonance imaging (MRI) showed an abnormal intensity of the spinal cord at the level of C7 to Th1 in the acute stage and severe atrophic change in the chronic stage. This is the first report of SCIWORA with positive diagnostic imaging. The mechanism of SCIWORA is discussed based on the positive MRI findings.

Thrombolytic therapy for delayed, in-hospital stroke after cardiac surgery

Five patients who had delayed stroke after cardiac surgery underwent intraarterial administration of a fibrinolytic agent for thromboembolism (n = 4) or thrombosis (n = 1) of the cerebral artery. Complete recanalization of the occluded artery was obtained in 3 patients and partial recanalization in 2. Additional angioplasty for basilar artery stenosis was performed in 1 patient. No patients exhibited rebleeding into the pericardial space or wound bleeding. All patients survived with moderate or full functional recovery. Immediate cerebral angiography and local thrombolysis may improve functional outcome and survival in patients with postcardiotomy cerebral thromboembolism.

Expression of N-myristoyltransferase in human brain tumors.

N-myristoylation is a process of covalent irreversible protein modification that promotes association of proteins with membranes. Based on our previous findings of elevated N-myristoyltransferase (NMT) activity in colonic epithelial neoplasms that appears at an early stage in colonic carcinogenesis, together with elevated NMT expression in human colorectal and gallbladder carcinomas, we investigated NMT activity and protein expression of NMT1 and NMT2 in human brain tumors and documented elevated NMT activity and higher protein expressions. For the first time, we have demonstrated that NMT has the potential to be used as a marker of human brain tumors. However, further studies with larger number of patients are required to establish its role as a complementary diagnostic tool. This finding has significant implications for further understanding of biological mechanisms involved in tumorigenesis, as well as for diagnosis and therapy of human brain tumors.

Magnetic resonance imaging of a fat embolism of the brain: case report.

A 22-year-old man developed fat embolism syndrome. Although a computed tomographic (CT) scan of the brain showed nothing abnormal, a magnetic resonance imaging scan detected scattered spotty areas of low intensity on T1-weighted images and of high intensity on T2-weighted images. Magnetic resonance imaging is thought to be more sensitive than computed tomography in detecting cerebral fat embolism syndrome and correlates well with the clinical course.