Morphologic and haemodynamic changes after stent placement for experimental carotid aneurysm.

SUMMARY: We investigated and compared the morphologic and haemodynamic changes between before and after stent placement when several different kinds of stents were applied to experimental aneurysms. Experimental aneurysms in eight pig carotid arteries were used. Stents were placed covering the aneurysm orifice. Five Cordis stents (coil stent), two GFXs (multilink stent), and one Multilink (tube stent) were used in this study. After stent placement, the arteries were perfused with 70% ethanol, the specimens were embedded in polyester plastic resin and thin slices were stained with hemtoxilin-eosin. Blood flow in the aneurysm was measured using digital subtraction angiography. The parent artery was stretched in multilink stent (GFX) cases, and was most markedly stretched by use of the tube stent (Multilink). Stent placement with any type of stent decreased intra-aneurysmal blood flow.

Morphologic and hemodynamic changes after stent placement for experimental carotid aneurysm.

SUMMARY: Stent assisted coil embolization is useful in treating broad neck aneurysms, and there are many kinds of stents that can be applied in the cerebral artery, however their characteristics are not well known. We investigated and compared morphologic and hemodynamic changes before and after stent placement when several different kinds of stents were applied to experimental aneurysms. Experimental aneurysms in eight pig carotid arteries were used. Stents were placed covering the aneurysm orifice. Five Cordis stents (coil stent), two GFXs (multilink stent), and one Multilink (tube stent) were used in this study. After coil placement, the arteries were perfused with 70% ethanol, the specimens were embedded in polyester plastic resin and thin slices were stained with hematoxylin-eosin. Blood flow in the aneurysm was measured using digital subtraction angiography. The parent artery was stretched in multilink stent (GFX) cases, and was most markedly stretched by use of the tube stent (Multilink). Stent placement with any type of stent decreased intra-aneurysmal blood flow.

Haemodynamic evaluation of cerebral arteriovenous malformations by quantification of transit time using high speed digital subtraction angiography: basic considerations.

It is important to evaluate the haemodynamics of cerebral arteriovenous malformations (AVMs) in order to predict and avoid complications following surgical intervention. This study measured the transit time of each component of AVMs by high-speed digital subtraction angiography (DSA) to understand the haemodynamics and to evaluate which parameter is an appropriate indicator for the monitoring. Eleven cases of cerebral AVMs were studied. Haemodynamics were evaluated by analysis of tracer transit using DSA. Tracer transit parameters including transit time and peak time were calculated by application of gamma fitting to time density curve, and measured in the following compartments; feeding artery, nidus and draining vein. Significant correlations of tracer transit parameters were present among compartments. Although there was no significant correlation of nidus volume and tracer transit parameters, the peak time was shorter in haemorrhage cases than in non-haemorrhage cases. Measurements of tracer transit parameters by high-speed DSA may be a useful tool for characterising and monitoring the haemodynamics of AVMs following surgical intervention.

Long-term effect of Helicobacter pylori infection on serum pepsinogens.

Serum pepsinogen values are markers of gastric mucosal status and of gastric cancer risk. The effect of Helicobacter pylori infection and sibship size on change of serum pepsinogen values over a seven-year span was investigated. Data from 2584 subjects with phlebotomy were analyzed both in 1989 and in 1996. The subjects were classified by H. pylori serology and sibship size (1 - 3 vs. 4 and more). Pepsinogen I (PG I) to II (PG II) ratio in '96 minus that in '89 was defined as DeltaPG I / II and compared among the groups. DeltaPG I / II was lower and decrease of PG I / II was more frequent among H. pylori-positive subjects than among negative subjects. The difference was owing to a decrease of PG I in all subjects and owing to an increase of PG II in those not younger than 30 years in '89. In H. pylori-positive subjects, those with a larger sibship size showed lower DeltaPG I / II and higher frequency of PG I / II decline. H. pylori infection exerts a reducing effect on PG I / II during the seven-year span. The effect of H. pylori is stronger among those with a larger sibship size, who are expected to have been infected with H. pylori in childhood. Inducing atrophy of gastric mucosa, which is reflected by a decline of PG I / II, may be one of the mechanisms through which H. pylori elevates the risk of gastric cancer.

Digital subtraction and conventional blood flow studies in porcine experimental aneurysms.

SUMMARY: Flow studies are important to understanding pathogenesis and treatment of cerebral aneurysms, but have not been possible in the clinical setting. We used experimental aneurysms established in and then removed from pigs to compare and correlate flow studies by high-speed video photography of introduced particles and by clinically applicable digital subtraction angiography. Venous pouches were used to create aneurysms in incised common carotid arteries. After aneurysms and parent arteries were removed, specimens were rendered translucent with solvents so they could be studied by video photography of introduced plastic particles in addition to digital subtraction angiography with iodinated contrast material. Regions of interest were studied individually. Mean transit time for contrast in the preparation correlated with videographically measured particle flow velocity (r = 0.616). Digital subtraction angiography should be useful in evaluation of flow in the clinical assessment and treatment of cerebral aneurysms, such as in endovascular therapy.

[A case of traumatic pseudoaneurysm of the middle meningeal artery treated with endovascular surgery].

A case of traumatic pseudoaneurysm treated by endovascular surgery is reported. The patient was a 20-year-old female. Acute epidural hematoma due to a traffic accident was removed. She was transferred to our hospital in the chronic stage after the operation, because traumatic pseudoaneurysm of the middle meningeal artery had appeared in the same location and had increased in size. We were able to eliminate the aneurysm by endovascular surgical treatment without craniotomy. Endovascular surgical treatment with embolization was less invasive to this patient with traumatic pseudoaneurysm of the middle meningeal artery than the usual surgical procedure.

Evaluation of intraaneurysmal blood velocity by time-density curve analysis and digital subtraction angiography.

PURPOSE: Our purpose was to evaluate intraaneurysmal blood velocity by using time-density curve analysis and digital subtraction angiography. METHODS: In 31 aneurysms, aneurysmal blood velocity was examined with digital subtraction angiography to determine mean transit time (MTF), peak density time (time to peak opacification) (PDT), and time to half-peak opacification (T1/2). Thirty frames per second were acquired, and the time-density curve was calculated. Regions of interest were drawn on the proximal parent artery, on the distal parent artery, and on the aneurysm itself. RESULTS: There was no significant difference in MTT of blood velocity in the proximal site on the parent artery, in the distal site on the parent artery, and in the aneurysm. Similarly, there was no significant difference in PDT in the parent artery, in the distal site on the parent artery, and in the aneurysm; nor was there a significant difference in T1/2 in the parent artery, in the distal site on the parent artery, and in the aneurysm; that is, intraaneurysmal blood velocity was similar to that in the parent artery. PDT and T1/2 of small aneurysms were faster than that of large aneurysms; that is, blood velocity of small aneurysms was faster than that of large aneurysms. CONCLUSION: Intraaneurysmal blood velocity in small aneurysms is similar to that in the parent artery; consequently, the central stream probably reaches the aneurysmal wall. Intraaneurysmal blood velocity in large aneurysms appears to be somewhat slower than that in small aneurysms.

Temporary shunt system with a heparin-coated inner surface for interruption of cerebral circulation: experiments in primates.

OBJECTIVE: Temporary interruption of the cerebral circulation is sometimes required during the course of neurosurgical procedures. It would be beneficial to develop some type of vascular shunt system that could be used when temporary interruption of the cerebral circulation is necessary. Recent advances in the production of hemocompatible materials suggested to us that it would be possible to develop a small caliber temporary shunt system. METHODS: We developed and investigated in primates a small caliber, temporary arterial shunt system. The heparin-coated shunt catheter was 30 cm in length and had an internal diameter of 1.2 mm. Five Japanese monkeys were used for these experiments. Flow was maintained for 3 hours through a shunt connecting the radial and carotid arteries. We investigated the following: 1) biocompatibility of the catheter, 2) patency of the system, 3) flow through the system, 4) histology of the inner surface of the catheter, 5) biochemical analysis of blood components adhering to the inner surface of the catheter, and 6) histology of perfused brain. RESULTS: Angiography performed through the shunt showed adequate distal cerebral perfusion. Flow through the catheters was 47+/-1.7 ml per minute. Analysis of the shunt catheter at the conclusion of the perfusion period showed no clot formation in the lumen by gross inspection or electron microscopy. CONCLUSION: This system could prove useful for preventing cerebral ischemia during the course of neurosurgical procedures in which the cerebral circulation must be temporarily interrupted.

Evaluation of Intra-aneurysmal Blood Flow: Investigation of the Flow in Experimental Aneurysms.

SUMMARY: We evaluated the flow in experimental pig aneurysms using a high speed video system with tracer particles and digital subtraction angiography (DSA). We found that flow velocity in experimental aneurysms was fast on the inflow of aneurysms. There was a certain correlation between mean transit time (MTT) and velocity in experimental aneurysms. Therefore, the differences of flow velocity in aneurysms will be detected using DSA. The flow in aneurysms was much changed by platinum coil embolization.

Preoperative detection of the composition of atherosclerotic plaque in the carotid artery using ultrasonography and magnetic resonance imaging.

Preoperative identification of the components of atherosclerotic plaque was attempted using ultrasonography in five patients and magnetic resonance (MR) imaging in three patients before carotid endarterectomy. The correlation between surgical and histological findings, and preoperative ultrasonography and MR imaging was evaluated. Plaque consisting predominantly of calcification appeared as bright echo on ultrasonography and was tough. Plaque consisting predominantly of hemorrhage was echolucent, appeared as low intensity on T2-weighted MR images and was fragile. Such preoperative assessment of plaque composition using ultrasonography and MR imaging is useful for manipulation of atherosclerotic plaque during carotid endarterectomy.

Multiple EDAS (encephalo-duro-arterio-synangiosis). Additional EDAS using the frontal branch of the superficial temporal artery (STA) and the occipital artery for pediatric moyamoya patients in whom EDAS using the parietal branch of STA was insufficient.

Although parietal EDAS or STA-MCA anastomosis are effective in pediatric moyamoya disease, they do not adequately prevent ischemia in the frontal and occipital lobes. Some additional methods that can prevent ischemia in the frontal and occipital lobes are sometimes needed. We investigated whether EDAS using a frontal branch of the superficial temporal artery (frontal EDAS) or EDAS using the occipital artery (occipital EDAS) is preferable. Frontal or occipital EDAS was performed at 15 sites in seven patients with pediatric moyamoya disease. The outcome was estimated by angiography 3 months later, CT findings 3 months later, neurological findings during the follow up period and perioperative complications. The mean follow up period was 14 +/- 6 months after frontal or occipital EDAS. As results, good revascularization from frontal or occipital EDAS was shown in ten of fourteen surgical sites (71%) in angiography. None of the patients showed deterioration of symptoms after frontal or occipital EDAS during the follow up period. None of the patients developed surgical complications. In conclusion, multiple EDAS using the frontal branch of STA and the occipital artery is an effective and safe method for preventing ischemia in the frontal and occipital lobe in pediatric moyamoya disease.

First-trimester prenatal molecular diagnosis of infantile hypophosphatasia in a Japanese family.

We obtained a prenatal molecular diagnosis during the first trimester in a Japanese woman whose first child (the proband) had been a compound heterozygote for infantile hypophosphatasia. We examined chorionic villus DNA samples obtained at 10 weeks of gestation for the base substitutions detected in the proband DNA using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) and PCR-allele-specific oligonucleotide (ASO) analysis. The genotype of the fetus was the same as that of the proband. The same mobility shift patterns of single strand conformation polymorphism (SSCP) bands were observed in the fetus and the proband. This molecular approach to prenatal diagnosis appears to be more accurate than the enzymatic method and also more accurate and more rapid than the conventional RFLP method.

Omental transplantation using a superficial temporal artery previously used for encephaloduroarteriosynangiosis.

BACKGROUND: Childhood moyamoya disease is a chronically progressive cerebrovascular occlusive disease affecting the territories of the anterior, middle, and posterior cerebral arteries. Surgery used in treatment of moyamoya disease to vascularize the brain include direct and indirect anastomoses. METHODS: Intracranial omental transplantation (OMT) was performed using a branch of the superficial temporal artery (STA) that had been used previously for encephaloduroarteriosynangiosis (EDAS) in five children with moyamoya disease. All five children continued to have paraparetic transient ischemic attacks (TIAs), urinary incontinence, and/or progressive mental retardation even after EDAS and/or STA-middle cerebral artery (MCA) anastomosis and encephalomyosynangiosis (EMS) to the territory of the MCA. Previously performed EDAS gave insufficient collaterals to the territory of the MCA in four of the five patients and sufficient collaterals to the territory of the MCA in the remaining patient. OMT was performed after stripping of a branch of the STA used in EDAS that gave insufficient collaterals to the brain in the former four patients; and the latter patient was performed using a parietal branch of the STA distal to the distal burr hole drilled in the previous EDAS. RESULTS: OMT resulted in marked improvement in neurologic conditions in all five patients. Four of the five patients suffered no TIAs postoperatively, while the remaining patient still had TIAs but at a markedly decreased frequency. CONCLUSIONS: In summary, OMT using a branch of the STA used in previously performed EDAS is required for patients with moyamoya disease who continue to manifest paraparesis, urinary incontinence, and/or progressive mental retardation even after multiple EDAS.

[A case report of the carotid cavernous fistula treated by endovascular embolization using interlocking detachable coil (IDC)].

To treat a carotid cavernous fistula, endovascular embolization using a detachable balloon technique is generally performed to close the fistula. However, the balloon sometimes becomes detached accidentally before reaching the orifice, so it is not an ideal device for closing a fistula from point of view of safety. This time, we performed transarterial endovascular embolization using Interlocking Detachable Coils (IDC) for a symptomatic CCF, and obtained a good result. A 32-year-old male, who was injured in a traffic accident developed symptoms of CCF after four months: edema and pain in the right conjunctiva, bruit at the right orbit. Angiography showed CCF, the orifice of which was located at the transitional portion of C4 and C5. IDC embolization was performed; three IDCs were placed at the cavity of the fistula through the orifice, and complete occlusion of the fistula was confirmed on angiography. Postoperative clinical course was good and symptoms were improved.

Effect of Guglielmi detachable coils on experimental carotid artery aneurysms in primates.

BACKGROUND AND PURPOSE: Clinical experience has established that intravascularly placed metal coils can be a useful treatment for cerebral vascular aneurysms. However, the mechanism by which the coils induce occlusion of the aneurysm is unclear. Appropriate use of this promising treatment modality requires basic understanding of the occlusive process. We used an animal model system of experimentally induced carotid aneurysms to investigate the initial events induced by Guglielmi detachable coils (GDCs), as well as the subsequent vascular changes induced by the coils over time. METHODS: We induced 23 aneurysms in the carotid arteries of 16 Japanese monkeys. Nineteen aneurysms were then occluded with GDCs placed via endovascular surgery; 4 aneurysms served as controls. We then used gross and microscopic pathological examination, angiography, and scanning electron microscopy to assess the effects of the GDC. RESULTS: In the first few hours after placement of the GDC in the experimental aneurysms, we observed leukocyte attachment and deposition of fibrinlike materials and other proteins. By 4 days after coil placement, leukocytes and fibroblasts were observed in the thrombus. By 2 weeks after coil placement, there was evidence of an endothelial-like covering of the coils. At 3 months after coil placement, we observed development of an arterial media in the occluded aneurysms. CONCLUSIONS: The GDCs initiated a cellular response within several hours of aneurysm occlusion. By 2 weeks after coil placement, endothelialization was proceeding, and by 3 months after occlusion, remodeling of the aneurysm had progressed to produce a media-like structure in the former aneurysm.

The association of smoking and drinking habits with serum pepsinogens.

BACKGROUND: The influence of smoking on serum pepsinogen I has been assessed. However, still to be assessed are the influences of smoking on pepsinogen II and drinking on serum pepsinogens. METHODS: Data were collected from 13,381 employees by questionnaire and serum tests. Multiple regression analyses were done with logarithms of serum pepsinogen I (LPI), pepsinogen II (LPII) or pepsinogen I/II ratio (LI/II) as a criterion variable and as categorized explanatory variables, sex, age, subjective symptoms in the stomach, past history of peptic ulcer, current smoking dose, past smoking amount, drinking habit and current drinking dose. RESULTS: Current smoking dose showed dose-dependent positive associations with LPI and LI/II: Past smoking amount yielded weakly dose-dependent negative associations with LPI and LI/II: Current drinking dose showed dose-dependent negative associations with LPI and LPII. CONCLUSION: Current smoking elevates pepsinogen I and the I/II ratio, and it may be necessary to consider the effect of smoking when pepsinogens are used as markers for gastric cancer. Drinking reduced pepsinogen I and II, but the effect was not so large.

Treatment with basic fibroblastic growth factor following focal cerebral ischemia does not prevent neuronal injury.

This experiment determined if postischemic administration of basic fibroblast growth factor (bFGF) would result in neovascularization to minimize neuronal injury following a focal cerebral ischemia insult. Fifty-eight Sprague-Dawley rats underwent middle cerebral artery (MCA) occlusion and were divided into three groups receiving either vehicle, serum, or 50 ng bFGF biweekly through an indwelling ventricular cannula. At variable time intervals, the animals underwent carbon black perfusion of capillary beds and histological staining for assessment of neuronal injury. Following MCA occlusion, there was a significant decrease in capillary bed density in peri-infarction cortex which normalized by two weeks. The number of alive neurons in the peri-infarction cortex was also significantly decreased compared to contralateral control cortex. The chronic administration of bFGF commencing two days after MCA occlusion did not result in either a significant increase in capillary bed density or the number of alive neurons in the peri-infarction cortex.

Hemodynamic disturbances in cerebral ischemia: correlation between positron emission tomographic and angiographic findings.

Proper treatment of ischemic stroke requires better understanding of cerebral hemodynamic changes. The hemodynamic changes associated with ischemia were measured using positron emission tomography and related to angiographic findings in the subacute and chronic stages of 17 ischemia patients who showed symptoms of main trunk stenosis of the internal carotid artery system. The hemodynamic factors, cerebral blood flow, cerebral blood volume, cerebral metabolic rate for oxygen, oxygen extraction fraction, and flow/volume ratio, were measured in regions of interest determined from the angiographic stenosis (over 50%) and compared in each stage. The cerebral blood flow and flow/volume ratio in the territory downstream of the main trunk stenosis and cerebral metabolic rate for oxygen in the whole cortex were decreased in the subacute stage. In the chronic stage, cerebral blood flow and flow/volume ratio decreased mainly in borderzone areas.

Positron emission tomographic measurement of acute hemodynamic changes in primate middle cerebral artery occlusion.

Specific hemodynamic changes in acute ischemia were investigated using a middle cerebral artery occlusion primate model and positron emission tomography. The cerebral blood flow (CBF), cerebral blood volume, oxygen extraction fraction (OEF), and cerebral metabolic rate for oxygen were measured 1, 3, and 9 hours after occlusion. OEF showed an increase in ischemic areas, and especially where CBF was below 18 ml/100 gm/min 1 hour after occlusion the OEF increased significantly (0.69 +/- 0.20, p < 0.05). Nine hours after occlusion, the OEF values were lower compared to those 1 and 3 hours after occlusion. Areas where CBF ranged from 18 to 31 ml/100 gm/min showed an increase in OEF at all times (p < 0.05). Clearly, OEF changes remarkably in the acute stage.