Natural Y-shaped radial artery graft bypass for a complex middle cerebral artery aneurysm: A case report.

Giant thrombosed middle cerebral artery (MCA) aneurysms are difficult to treat and sometimes require complex revascularization using allografts. We describe a technical method using revascularization with a natural Y-shaped graft that provides a normal variation for a complex MCA aneurysm. A 65-year-old man with a giant thrombosed MCA aneurysm presented with right hemiparesis and aphasia. The patient had a history of clipping surgery for the ipsilateral side of the MCA aneurysm 25 years before, and a de novo aneurysm developed over the previous 18 years. For the giant thrombosed aneurysm, trapping and revascularization were performed. A natural radial artery Y-graft was used as the graft and anastomosed to both M2 trunks. The symptoms improved after surgery, and the patient was discharged 3 weeks later. This is the first report of a double-barrel bypass using a natural Y-graft. This method attained a normal variation, and the flow of the Y-graft was physiological. For the radical cure of giant thrombosed MCA aneurysms, multiple revascularizations might be required. With this natural Y-graft, complex transpositions could be avoided.

Inflammation promotes progression of thrombi in intracranial thrombotic aneurysms.

Advances in the understanding of the pathogenesis of arteriosclerosis, abdominal aorta aneurysms and dissections, and carotid artery plaques have focused on chronic inflammation. In this study, we report that inflammatory changes of thrombi contribute to the enlargement and growth of giant intracranial thrombotic aneurysms. Surgical and postmortem samples were collected from 12 cases of large or giant intracranial thrombotic aneurysms diagnosed via pathological investigations. Degeneration of the aneurysmal wall and the infiltration of inflammatory cells in the thrombi were assessed. The number of blood cells and immunohistochemical stain-positive cells was enumerated, and the inflammation and neovascularization in the thrombi were assessed. In all cases, the appearance of inflammatory cells (CD68+ cells, CD206+ cells, lymphocytes, and neutrophils) was apparent in the thrombi. The number of CD34+ cells was moderately correlated with the number of CD68+ cells, and CD34+ cells significantly and strongly correlated with the number of CD206+ cells. Based on the number of neutrophils per CD68+ cells, we classified the cases into 2 groups: a macrophage inflammation-dominant group and a neutrophilic inflammation-dominant group. The neutrophilic inflammation-dominant group had significantly more cases with previous treatments and neurological symptoms due to mass effect than the macrophage inflammation-dominant group. Chronic inflammation due to macrophages in thrombi is a fundamental mechanism in the enlargement of an intracranial thrombotic aneurysm, and neutrophilic inflammation can accelerate this process. Microvascularization in thrombi is linked to inflammation and might promote thickening of the intima and repeated intimal microbleeds.

Heat generation by ultrasonic bone curette comparing with high-speed drill.

BACKGROUND: Ultrasonic bone curettes have been used as with high-speed drills. However, the amount of heat generated by the ultrasonic bone curette is not well known. This study quantitatively assessed the heat generated by an ultrasonic bone curette and compared it to that by a high-speed drill. METHODS: The thermal change in a swine skull during bone curetting using an ultrasonic device and a high-speed drill were assessed. The investigation focused on the type of surgical manipulation (brush-like strokes vs. pushing motion) and irrigation (room temperature vs. cold water; low-volume irrigation vs. high-volume irrigation). RESULTS: The thermal elevation during drill use was suppressed when using brush-like strokes compared to pushing motion (brush-like strokes, 44.7 °C; pushing motion, 69.2 °C; p < 0.01). Cold-water irrigation while drilling had a small effect compared to room temperature (RT) water (RT, 44.7 °C; cold, 35.2 °C; p = 0.12). The temperature generated by the curette was higher than that generated by the drill (curette, 72.5 °C; drill, 44.7 °C; p < 0.01). High-volume irrigation was required to reduce the heat generated by the curette (no irrigation, 88.6 °C; low-volume, 72.5 °C; high-volume, 60.5 °C; p < 0.01). CONCLUSIONS: The ultrasonic bone curate generated more heat than the high-speed drill. During surgical manipulation, the use of brush-like strokes by both the high-speed drill and the ultrasonic bone curette is necessary to avoid excess thermal elevation. Irrigation with RT water is sufficient to avoid heat generation. High-volume irrigation is required to reduce the heat generated by the curette.

The influence of hypoglycemia on cerebral blood flow in cases of hypoglycemic coma.

The authors report two cases of hypoglycemic coma in which both diffusion-weighted imaging (DWI) and single photon emission computed tomography (SPECT) were used. A 74-year-old woman (case 1) presented with deep coma associated with hypoglycemia (blood glucose level: 20 mg/dl), and DWI on admission revealed extensive hyperintensity lesions. SPECT obtained on the second hospital day revealed diffuse hyperperfusion and a follow-up SPECT on the eighth hospital day showed relative hypoperfusion. An 89- year- old woman (case 2) presented with coma associated with hypoglycemia (blood glucose level: 45 mg/dl), and DWI showed diffuse hyperintensity lesions in both hemispheres. SPECT obtained on the ninth hospital day showed relative hypoperfusion compared to the first scan obtained on the third hospital day. Although the blood glucose level was rapidly corrected, the level of consciousness remained unchanged in both cases. Our results suggest that cerebral blood flow may increase even after glucose correction and that relative hypoperfusion could occur in the subacute stage of hypoglycemic coma.

Internal trapping following proximal clipping for a ruptured partially thrombosed giant aneurysm of the vertebral artery--case report.

A 52-year-old woman presented with a partially thrombosed giant aneurysm of the vertebral artery (VA) manifesting as a 3-month history of left hemiparesis. She developed subarachnoid hemorrhage during hospitalization and underwent emergency surgery for surgical proximal clipping and ventricular drainage with decompressive suboccipital craniectomy. She underwent additional surgery for endovascular coil embolization of the aneurysm and the affected distal VA on the 7th postoperative day. Although she suffered transient lower cranial nerve pareses and respiratory failure, her neurological condition improved gradually and she returned home with only slight ataxia and hoarseness 3 months after surgery. Magnetic resonance imaging obtained 28 months postoperatively revealed a remarkable decrease in the size of the aneurysm as well as reduction of the mass effect on the brainstem. Combined proximal clipping and internal trapping can solve the problems associated with treatment of giant aneurysms of VA by either direct surgery or endovascular surgery, and should be considered as a therapeutic option for giant aneurysms of the VA.

Reversible diffusion-weighted imaging changes in the splenium of the corpus callosum and internal capsule associated with hypoglycemia - case report - .

A 63-year-old man presented with hypoglycemia-induced hemiparesis manifesting as diffusion-weighted magnetic resonance (MR) imaging changes in the splenium of the corpus callosum and internal capsule which disappeared after glucose administration. Clinicians should be aware that hypoglycemia can cause reversible splenium abnormalities on MR imaging, although the underlying mechanism still remains unclear, as this may be helpful in the differential diagnosis of hypoglycemia-induced hemiparesis and stroke.