A classification of juxta-dural ring aneurysms with reference to surgical anatomy

We report a subgroup of internal carotid artery (ICA) aneurysms located near the carotid ring which we call juxtadural ring aneurysms. These aneurysms are classified into three types: paraclinoid intradural, carotid cave and infraclinoid extradural aneurysms. The paraclinoid intradural aneurysms arise from the ICA distal to the origin of the ophthalmic artery and are close to the dural ring, which may include some so-called carotid-ophthalmic aneurysms. The carotid cave aneurysms are located in the carotid cave which is seated in the infraclinoid carotid groove and proximal to the origin of the ophthalmic artery. They are located at the angiographical genu and in the intradural space anatomically. The infraclinoid extradural aneurysms are located close to the dural ring extradurally in the infraclinoid carotid groove sinus, a peripheral venous space of the cavernous sinus. The infraclinoid extradural aneurysms should be differentiated from aneurysms in the cavernous sinus, because they are located in the infraclinoid carotid groove sinus.

Impact of diabetes and glycaemic control on peripheral artery disease in Japanese patients with end-stage renal disease: long-term follow-up study from the beginning of haemodialysis

AIMS/HYPOTHESIS

End-stage renal disease (ESRD) patients with diabetes have been regarded as being at the highest risk of cardiovascular disease. We therefore investigated the relationship between diabetes and the incidence of peripheral artery disease (PAD) in new haemodialysis patients.

METHODS

We enrolled 1,513 ESRD patients who had just begun haemodialysis therapy. They were divided into two groups: those with (n = 739) and those without diabetes (n = 774). The endpoint was the development of PAD, defined as ankle brachial pressure index ≤ 0.9 or toe brachial pressure index <0.7 in patients with an ankle brachial pressure index >0.9.

RESULTS

According to the Kaplan-Meier method, the 10 year event-free rate for development of PAD and lower limb amputation was significantly lower in the diabetes group than in the non-diabetes group (60.3% vs 82.8%, HR 2.99, 95% CI 2.27, 3.92, p<0.0001 and 93.9% vs 98.9%, HR 5.59, 95% CI 2.14, 14.7, p = .0005 for PAD and lower limb amputation, respectively). In patients with diabetes, quartile analysis of HbA1c levels showed that the highest quartile group (≥ 6.8% [51 mmol/mol]) had significant development of PAD and lower limb amputation compared with lower quartile groups (PAD HR 1.63, 95% CI 1.17, 2.28, p = .0038; lower limb amputation HR 2.99, 95% CI 1.17, 7.70, p = .023).

CONCLUSIONS/INTERPRETATION

Diabetes was a strong predictor of PAD after initiation of haemodialysis therapy in patients with ESRD. In addition, higher HbA1c levels were associated with increased risk of developing PAD and requiring limb amputation in such diabetic populations.

Peierls mechanism of the metal-insulator transition in ferromagnetic hollandite K2Cr8O16

Synchrotron x-ray diffraction experiment shows that the metal-insulator transition occurring in a ferromagnetic state of a hollandite K(2)Cr(8)O(16) is accompanied by a structural distortion from the tetragonal I4/m to monoclinic P112(1)/a phase with a √2×√2×1 supercell. Detailed electronic structure calculations demonstrate that the metal-insulator transition is caused by a Peierls instability in the quasi-one-dimensional column structure made of four coupled Cr-O chains running in the c direction, leading to the formation of tetramers of Cr ions below the transition temperature. This provides a rare example of the Peierls transition of fully spin-polarized electron systems.

Brachial-ankle pulse wave velocity predicts increase in blood pressure and onset of hypertension

BACKGROUND

The present study was designed to test the hypothesis that brachial-ankle pulse wave velocity (baPWV) predicts longitudinal increases in blood pressure (BP) and new onset of hypertension in individuals with normal BP.

METHODS

baPWV was measured using a semiautomated device in 2,496 participants (27-84 years) without hypertension who visited our hospital for a yearly health check-up. They were followed up for 4 years with the endpoint being development of hypertension.

RESULTS

During the follow-up period (median, 733 days; actual follow-up, 5,215 person-years), hypertension developed in 698 participants (133.8/1,000 person-years). Kaplan-Meier analysis revealed that risk for hypertension was increased across the tertiles of baseline baPWV. The hazard ratio (first tertile as reference) was 2.02 (95% confidence interval (CI) 1.55-2.64) and 3.49 (95% CI 2.66-4.57) in the second and third tertiles, respectively, after adjustment for possible risk factors. Multivariate Cox proportional hazard regression analysis adjusted for known risk factors, where baPWV was used as a continuous variable, also indicated that the baseline value of baPWV independently predicted new onset of hypertension (P < 0.001). Furthermore, baseline baPWV was significantly associated with a longitudinal increase in BP after adjustment for known risk factors in multiple regression analysis (P < 0.001).

CONCLUSION

This study provides the first evidence that baPWV is an independent predictor of longitudinal increases in BP as well as of new onset of hypertension.

Development of a high-efficiency high-resolution particle-induced x-ray emission system for chemical state analysis of environmental samples

We have developed a high-efficiency high-resolution particle-induced x-ray emission (PIXE) system employing a von Hamos-type crystal spectrometer for a chemical state identification of trace elements in environmental samples. The energy resolution of the system was determined to be about 0.05% through the observation of Si Kalpha(1,2) x rays (1.74 keV) from elemental silicon. The throughput efficiency of the system was also evaluated quasitheoretically to be 1.6x10(-7) counts/incident proton for Si Kalpha(1,2) emission. To demonstrate a chemical state analysis using the high-resolution PIXE system, Si Kalpha(1,2) and Kbeta x-ray spectra for SiC, Si(3)N(4), and SiO(2) were measured and compared. The observed chemical shifts of the Si Kalpha(1,2) peaks for SiC, Si(3)N(4), and SiO(2) relative to elemental silicon were 0.20, 0.40, and 0.55 eV, respectively. The tendency of these shifts were well explained by the effective charges of the silicon atoms calculated by a molecular orbital method.

Coronary artery disease investigated using 99mTc-tetrofosmin myocardial SPECT

BACKGROUND

Coronary artery disease can be diagnosed from stress and delayed images of myocardial single photon emission computed tomography (SPECT) using technetium-99 m-tetrofosmin (TcTF). However, the negative predictive value of stress SPECT images after a single injection of a low tracer dose remains unknown. Thus, the present study investigates whether normal stress SPECT results predict event-free survival.

MATERIALS AND METHODS

We screened 302 consecutive patients who were randomly assigned to two groups for myocardial ischaemia using either stress SPECT with a low dose of TcTF (296 MBq, TcTF group, n = 150) or stress together with rest SPECT using thallium(201) chloride (TlCl, 111 MBq; TlCl group, n = 152) as the tracer. A total of 80 patients with abnormal SPECT findings were excluded and the remaining 222 with normal results (age, 66.5 +/- 0.7 years; TcTF/TlCl, 112/110) were enrolled in the present study and followed up for 401 +/- 9 days, with the endpoint being ischaemic cardiac events.

RESULTS

The incidence of cardiac events did not differ between the two groups (0.9% and 0.0% in TcTF and TlCl groups, respectively). The cost and duration of TcTF and TlCl SPECT examinations were about 425 and 603 Euros and 50 and 280 min, respectively.

CONCLUSIONS

The negative predictive values of stress SPECT using a low dose of TcTF and of combined stress and rest SPECT using TlCl did not differ and both were clinically acceptable. Thus, stress SPECT using low dose TcTF is useful in screening patients for myocardial ischaemia.

Brain natriuretic peptide detects cardiac abnormalities in mass screening

BACKGROUND

Plasma brain natriuretic peptide (BNP) is elevated in asymptomatic patients with various cardiac abnormalities. We tested the hypothesis that measuring BNP is useful for detecting asymptomatic patients with cardiac abnormalities who are not identified by conventional health check-up programmes.

MATERIALS AND METHODS

From 2001 to 2002, 6189 subjects (women 34.0%; mean age 56.6 years) underwent multiphasic health check-ups in our hospital, of which 4818 without cardiac abnormalities as revealed by the health check-up were enrolled in the present study. Their plasma concentrations of BNP were measured.

RESULTS

Plasma concentrations of BNP were higher than the normal reference upper limit of our hospital (21.3 pg mL(-1)) in 925 of the 4818 subjects. Echocardiography was performed in 471 subjects who were randomly selected from the 925 subjects with elevated BNP. Abnormal findings were detected in 174 subjects, comprising valvular heart disease in 83, systolic dysfunction in 10, diastolic dysfunction in 54, left ventricular hypertrophy in 41, left ventricular enlargement in 11, left atrial enlargement in 13 and paroxysmal atrial fibrillation in 3.

CONCLUSIONS

Since BNP measurement identifies additional subjects with cardiac abnormalities, it is useful for detecting asymptomatic cardiac abnormalities among apparently healthy subjects, and is suitable for use in high-quality mass screening.

Brain natriuretic peptide in the prediction of recurrence of angina pectoris

BACKGROUND

Circulating levels of brain natriuretic peptide (BNP) provide prognostic information for patients with heart failure, but little is known about its prognostic usefulness in patients with stable angina pectoris. We investigated whether BNP could be used as a marker for the prediction of anginal recurrence after successful treatment.

DESIGN

Brain natriuretic peptide levels of 77 patients with stable angina pectoris were measured at enrolment and after confirmation of successful treatment (i.e. no anginal attack for at least 6 months: chronic phase) with percutaneous transluminal coronary angioplasty and/or conventional medication. Then, we prospectively followed them up for 25.9 +/- 1.4 months, with the endpoint being a recurrence of anginal attacks.

RESULTS

An anginal attack recurred in seven patients. In patients without recurrence, BNP levels in the chronic phase (21 +/- 12 [median +/- median absolute deviation] pg mL-1) were lower than those measured at enrolment (46 +/- 25 pg mL-1, P < 0.0001), whereas the levels in patients with recurrence increased during the same period (from 36 +/- 16 to 72 +/- 42 pg mL-1, P < 0.05). A univariate analysis revealed that the BNP level measured in the chronic phase was the significant predictor of future anginal recurrence. Analysis of the receiver operating characteristic curve indicated that the cutoff level of BNP in the chronic phase was 68 pg mL-1. The Kaplan-Meier method revealed that the incidence of anginal recurrence was higher in patients with higher (71.4%) than lower levels of BNP (2.9%; P < 0.0001).

CONCLUSIONS

Measurement of BNP levels after successful therapy is clinically useful for the prediction of recurrence of anginal attacks in patients with angina pectoris.

Circulating concentrations of cardiac proteins indicate the severity of congestive heart failure

OBJECTIVE

To test the hypothesis that myocardium specific proteins may be useful markers for evaluating the severity of congestive heart failure.

METHODS

Serum concentrations of myosin light chain I (MLC-I), heart fatty acid binding protein (H-FABP), creatine kinase isoenzyme MB (CK-MB), and troponin T (TnT) and plasma concentrations of brain natriuretic peptide (BNP) were determined in 48 patients with acute deterioration of congestive heart failure, both before and after effective treatment.

RESULTS

Before treatment, MLC-I (mean (SEM) 3.2 (2.2) microg/l), H-FABP (9.0 (3.5) microg/l), TnT (30 (21) ng/l), and BNP (761 (303) ng/l) were higher than the normal reference range, and concentrations of CK-MB (5.4 (2.9) microg/l) were near normal. Treatment of congestive heart failure with conventional medication significantly decreased the concentrations of MLC-I (1.2 (0.3) microg/l, p < 0.0001), H-FABP (6.0 (2.0) microg/l, p < 0.0001), CK-MB (2.9 (1.5) microg/l, p < 0.0001), TnT (9 (1) ng/l, p < 0.001), and BNP (156 (118) ng/l, p < 0.0001). The decreases in H-FABP and CK-MB concentrations after treatment correlated with the decrease in BNP concentrations (p < 0.05). The absolute concentrations of MLC-I, H-FABP, CK-MB, and TnT correlated positively with those of BNP (p < 0.01).

CONCLUSIONS

These findings suggest that MLC-I, H-FABP, CK-MB, and TnT may be used as reliable markers for the evaluation of the severity of congestive heart failure.

Effect of artificial carbon dioxide foot bathing on critical limb ischemia (Fontaine IV) in peripheral arterial disease patients

BACKGROUND

It has been reported that artificial carbon dioxide (CO(2)) foot bathing improves subcutaneous microcirculation in peripheral arterial disease (PAD) patients. However, the effect for critical limb ischemia (CLI) with ulceration or gangrene (Fontaine stage IV) is not identified. The physiological effects of CO(2) bathing and the outcome of limb salvage in such patients were studied.

METHODS

In 18 healthy volunteers (Study I), the dorsal pedis peripheral blood flow was measured by a laser Doppler flow-meter during CO(2) foot bathing (1000 ppm, 37 degrees C) for 10 min. A Holter electrocardiogram was also recording in the same period. Blood flow and cell volume significantly increased during bathing. Eighty-three CLI limbs (Fontaine IV) in 68 PAD patients (Study II) underwent artificial CO(2) foot bathing (for 10 minutes twice daily >2 months) were followed up >6 months.

RESULTS

In Study I, analysis of heart rate variability showed that high frequency amplitude (HFA) considerably increased and the ratio of low frequency amplitude to HFA (LF/HF) noticeably decreased during bathing. In Study II, 69 limbs (83.1%) could be salvaged. Twenty-seven of 28 limbs (96.4%) which have ulcer and gangrene in only one toe, 13/16 limbs (81.2%) in multiple toes and 29/39 limbs (74.4%) in all toes and/or heel respectively were saved.

CONCLUSIONS

The effect of CO(2) enriched water on the subcutaneous microcirculation might be brought about by peripheral vasodilation reflected by increased parasympathetic and decreased sympathetic activity, and the artificial CO(2) foot bathing is clinically effective on salvage of CLI (Fontaine stage IV) limbs.

Transradial approach for diagnostic selective cerebral angiography: results of a consecutive series of 166 cases

BACKGROUND AND PURPOSE

Diagnostic selective cerebral angiography is commonly performed via transfemoral and transbrachial approaches. With these approaches, however, patients occasionally suffer serious complications. The purpose of this study was to evaluate the feasibility, efficacy, and safety of a transradial approach as an alternative to the transfemoral and transbrachial approaches.

METHODS

Between October 1998 and September 1999, transradial cerebral angiography was performed in 166 consecutive patients in a single center as a diagnostic procedure. Before the procedure, we confirmed the collateral blood supply to the hand from the ulnar artery using a modified Allen test. Regular catheterization techniques were practiced using our newly designed 120-cm-long 4F catheter. In 42 patients, anticoagulant and/or antiplatelet therapy was given perioperatively.

RESULTS

Twelve of the 166 patients proved to be poor candidates for the transradial approach, owing to restlessness (n = 9), lack of collateral blood supply via the ulnar artery (n = 2), and brachial artery stenosis (n = 1). The radial artery was successfully punctured and cannulated in the remaining 154 patients. Selective catheterization of the intended vessels was obtained in all carotid and vertebral angiographic procedures with no major vascular complications.

CONCLUSION

Compared with transfemoral and transbrachial approaches, the transradial approach is a less invasive and safer technique for selective cerebral angiography and may warrant consideration as a standard procedure. Anticoagulant or antiplatelet therapy need not be discontinued for this method.

[Increased incidence of coronary artery disease and cardiac death in elderly diabetic nephropathy patients undergoing chronic hemodialysis therapy]

OBJECTIVES

The incidence of coronary artery disease and cardiac death was investigated in elderly diabetic patients undergoing chronic hemodialysis therapy.

METHODS

Three hundred thirty-five patients who began hemodialysis therapy since 1992 were followed up by echocardiography and treadmill exercise testing. Coronary angiography was also performed in patients with angina pectoris. Angina pectoris was defined as clinical symptoms > Canadian Cardiovascular Society classification II, and asynergy findings by echocardiography or ST depression > 0.1 mV during the treadmill exercise test. Coronary artery stenosis was defined as narrowing > or = 75%. Patients were divided into 4 groups: diabetic nephropathy (DN) > or = 65 years old (Group O/DN, n = 56), DN < 65 years old (Group Y/DN, n = 84), non-DN > or = 65 years old (Group O/non-DN, n = 76) and non-DN < 65 years old (Group Y/non-DN, n = 119).

RESULTS

Between 1992 and 1998, there were 137 patients with angina pectoris (40.9%), 79 with coronary artery stenosis (23.6%) and 37 with cardiac death (11.0%). Cumulative incidences of angina pectoris, coronary artery stenosis and cardiac death were significantly higher in the following order of groups; O/DN > Y/DN > O/non-DN > Y/non-DN. Five-year cumulative incidences of angina pectoris, coronary artery stenosis and cardiac death in Groups O/DN vs Y/non-DN were 72.2% vs 38.6%, 53.7% vs 12.2% and 50.6% vs 3.5%, respectively. Relative risks of aging and diabetic nephropathy for angina pectoris, coronary artery stenosis and cardiac death were 3.8, 7.9 and 22.4, respectively (p < 0.0001).

CONCLUSIONS

Aging and the presence of diabetes are strong risk factors for coronary artery disease and cardiac death in hemodialysis patients. Therefore, diagnosis and treatment of coronary artery disease should be achieved at the early stage of hemodialysis therapy.

Transradial approach for selective cerebral angiography: technical note

Selective cerebral angiography is currently being performed using transfemoral and transbrachial approaches. However, these techniques require patients to tolerate a prolonged focal compression and sometimes cause serious complications such as pulmonary embolism. The authors describe a technique of transradial approach as a safer selective cerebral angiography. Between July 1997 and November 1998, 70 patients underwent selective cerebral angiography with a transradial approach using a 4-F catheter. The collateral blood supply to the hand from the ulnar artery was confirmed using Allen's test prior to the procedure. To prevent the mechanical spasm of the radial artery, an arterial introducer 20 cm long was used. The radial artery was successfully punctured and cannulated in all patients. Selective catheterization of the intended vessels was obtained in over 98% of the carotid angiography and over 95% of the vertebral angiography. No major vascular complications such as cerebral infarction, upper limb ischemia, significant local hematoma or pseudoaneurysm were experienced. The transradial approach is a less invasive and safer technique for selective cerebral angiography, and could be an alternative to transfemoral and transbrachial approaches.

Prognostic value of heart rate variability during long-term follow-up in chronic haemodialysis patients with end-stage renal disease

BACKGROUND

Mortality is high in chronic haemodialysis patients with cardiovascular disease, and many of them die suddenly. Reduced heart rate variability (HRV) is an increased risk for death in various populations, but its prognostic value in haemodialysis patients remains uninvestigated.

METHODS

We analysed the associations between 24-h HRV measures and long-term mortality through a prospective follow-up of 31 chronic haemodialysis patients who underwent diagnostic coronary angiography.

RESULTS

Of the 31 patients, at baseline, seven had a previous myocardial infarction, five had a history of congestive heart failure and 14 had significant (> or =75%) coronary stenosis (four had multi-vessel stenosis). During follow-up for 60+/-5 months, 14 patients died, 11 of them suddenly. A left ventricular ejection fraction of <0.45, multi-vessel coronary stenosis, ventricular tachycardia on 24-h ECG and decreased/abnormal 24-h HRV (triangular index <22 and abnormal Poincaré plot) carried a univariate risk of all-cause death, while the risk of sudden death was only correlated with decreased HRV (standard deviation of normal-normal R-R interval <50 ms, triangular index <22 and ultra-low frequency power <8.7 ln(ms2)). Multivariate analysis revealed that a triangular index <22 was the best predictor of increased risk for both all-cause and sudden death (hazards ratio (95% CI); 8.1 (1.3-48.6) and 12.6 (1.3-126.4), respectively) and that the association was independent of cardiac function, macrovascular diseases, ventricular arrhythmias and cardiovascular risk factors. The 5-year mortality when the triangular index was > or =22 or <22 was 33 or 88% for patients with coronary artery disease and 0 or 50% for those without.

CONCLUSIONS

These results indicate that HRV has an independent prognostic value in chronic haemodialysis patients and identifies an increased risk for all-cause and sudden death.

Identification of the Oka strain of the live attenuated varicella vaccine from other clinical isolates by molecular epidemiologic analysis

A method was developed to distinguish the Oka vaccine strain of varicella-zoster virus (VZV) from other clinical isolates. The molecular characteristics of 52 clinical isolates from varicella or zoster patients with no history of VZV vaccination and the Oka strain, including vaccine and parental viruses, were analyzed by PstI cleavage of the PstI site-less (PSL) region. This was followed by single-strand conformational polymorphism (SSCP) after polymerase chain reaction amplification of repeating region 2 (R2). Most of the clinical isolates tested, especially recent isolates, had a PstI site in the PSL region, but the Oka strain did not. The SSCP patterns of R2 in Oka strain virus differed from those of other viruses. These results suggest that analysis of the PstI site followed by SSCP of R2 will be useful for identifying the Oka vaccine virus in isolates.

A case of a dialysis patient with sclerosing peritonitis successfully treated with corticosteroid therapy alone

Sclerosing peritonitis (SCP) is a rare complication of peritoneal dialysis. Most of the patients with this serious complication have been treated in a symptomatic and conservative manner. Other patients have undergone risky surgical interventions. Recently it was reported that immunosuppressive therapy after renal transplantation was effective for this complication. A 56-year-old man developed sclerosing peritonitis 5 months after switching from peritoneal dialysis to hemodialysis because of ultrafiltration failure. The patient had ongoing inflammatory signs and symptoms, and corticosteroid therapy was commenced. His condition was dramatically improved within 1 week, and he is now well on an outpatient basis with the maintenance dosage of corticosteroid. This is the first report of a patient with peritoneal dialysis-related SCP who responded favorably to corticosteroid therapy alone.

[Evaluation of a method to determine the myocardial uptake from 123I-BMIPP myocardial SPECT and its significance]

We examined methods of calculating myocardial uptake (TU) of 123I-BMIPP by SPECT, and compared TU to heart function (ejection fraction (EF), cardiac output (CO), cardiac index (CI)) calculated by left ventriculography. Forty-two patients with acute myocardial infarction were classified into 5 groups; within 1 week (I), from 1 to 2 weeks (II), from 2 weeks to 1.5 months (III), from 1.5 to 3 months (IV) and more than 3 months (V) after percutaneous transluminal coronary angioplasty (PTCA). Chest depth (Tw) was calculated by measuring the thoracic absorption rate of 123I. In calculating TU, the myocardial count was calculated from short-axis tomograms, and then absorption was corrected using Tw to calculate each value on early-phase image (E) and delay-phase image (D). The influence of lung uptake on myocardial count was only 1.76%. When TU was compared to heart function, there were correlations between group I and group V. Especially in group V D-TU was a significantly correlated with heart function. In heart function CI, but not EF nor CO, was significantly correlated with TU. It was suggested that the correlation between TU and heart function reflected the infarct condition before PTCA in group I, and that the individual difference in recovery of fatty acid metabolism in group V. The significant correlation between D-TU and CI suggests that D-TU reflects heart function and fatty acid metabolism, although TU is influenced by differences in physical status.

Autonomic dysfunction in hemodialysis patients with persistent hypotension

To investigate autonomic mechanisms underlying persistent hypotension in long-term hemodialysis patients, high-frequency (HF, > 0.15 Hz) and low-frequency (LF, 0.04-0.15 Hz) components of heart rate variability and plasma noradrenaline were analyzed in 10 persistently hypotensive hemodialysis patients (group H), 11 normotensive patients (group N) and 10 healthy controls (group C). The HF amplitude, an index of cardiac parasympathetic activity, and LF-to-HF ratio, an index of sympathetic predominance, were in the order of groups C > N > H (p < 0.01). While the HF amplitude decreased with standing in all three groups (p < 0.05 for all), the LF-to-HF ratio increased only in groups N and C (p < 0.05 for both) but not in group H. Conversely, plasma noradrenaline level was in the order of groups C < N < H (p < 0.001). Furthermore, while the LF-to-HF ratio correlated positively with the plasma noradrenaline level in group C (r = 0.73, p < 0.01), it correlated negatively in group H (r = 0.69, p < 0.05). These results indicate that an impairment in both parasympathetic and sympathetic functions exists in hemodialysis patients with persistent hypotension, and that the apparent sympathetic dysfunction could result from a reduction in cardiovascular responsiveness to sympathetic stimulation.

Intraoperative regional and functional thermography during resection of cerebral arteriovenous malformation

We present the first use of intraoperative thermographical imaging for the surgical resection of a cerebral arteriovenous malformation. For obtaining intraoperative regional and functional thermographical images, a real-time mode infrared camera was installed to an operating microscope with an exclusively developed attachment device. Changes of the surface temperature of the cortical draining vein and the surrounding cortical surface were observed intraoperatively before and after the occlusion of the main feeder. Intraoperative functional thermography with cold physiological saline solution demonstrated a change in the heat clearance of the draining vein after complete obliteration of the feeder.

Stenotic lesions in vascular access: treatment with transluminal angioplasty using high-pressure balloons

In our institute, one hundred sixty-four balloon dilatations of stenotic lesions in vascular access have been performed since November 1991. All of these procedures were done with high-pressure balloon catheters. In addition to seventy-four cases treated with only percutaneous transluminal angioplasty, there were thirty-four cases which were treated by thrombectomy and/or surgical revision with subsequent intraoperative balloon angioplasty. These angioplastic procedures were initially successful in 142 (87%) of 164 stenoses. The patency rate after 3 months was 68%; after 6 months, 42%; and after 1 year, 25%. There were no serious adverse reactions in our series. This procedure can be safely done with minimal traumatization and, although long-term patency rates are low, repeated dilatations can be performed with ease, when restenosis occurs, to keep a fistula functioning for a long time in appropriate patients.

Functional image of dynamic computed tomography in diagnostic and prognostic evaluation of ischemic stroke within the first 6 hours

BACKGROUND AND PURPOSE

It is important to make a diagnosis before a low-density area appears on computed tomography for appropriate management of acute ischemic stroke. We report the diagnostic and prognostic usefulness of functional image of dynamic computed tomography for acute ischemic stroke.

METHODS

Forty-seven patients with ischemic strokes within 6 hours of ictus underwent dynamic computed tomography in which functional images were obtained. These findings were compared with angiographic findings, follow-up computed tomography, and clinical outcome.

RESULTS

The functional images were categorized into three groups: (1) cortical type: abnormalities on time to peak image and/or corrected mean transit time image involving mainly cortical structures (29 cases); (2) noncortical type: abnormalities on either or both images limited to noncortical structures (7 cases); and (3) normal type: no abnormalities on both images (11 cases). Cortical type as a diagnostic test for arterial trunk occlusion had a good sensitivity (100%), specificity (95%), and accuracy (98%). Infarction volume on follow-up computed tomography correlated with extension of prolonged time-to-peak area (r = .80, P < .01) and that of prolonged corrected mean transit time area (r = .81, P < .01). Cortical type was associated with significantly unfavorable outcome (P < .01).

CONCLUSIONS

Functional image of dynamic computed tomography findings predicted arterial trunk occlusion, infarction volume, and clinical outcome. Therefore, this technique would be useful not only for indicating definitive angiography and subsequent therapy but for evaluating the effectiveness of surgical or medical recanalization.

Effects of high-dose vitamin B6 therapy on microcytic and hypochromic anemia in hemodialysis patients

In an attempt to treat hemodialysis patients suffering from microscopic and hypochromic anemia (MHA) and who are either sufficient or deficient in serum ferritin level, we investigated the effects of oral administration of vitamin B6 (VB6). Twenty-six patients with MHA undergoing long-term stable hemodialysis treatment were divided into three groups. There was no significant difference in the serum VB6 levels in these patients as compared with normal subjects before the study. Patients in group I, whose serum ferritin levels were normal, were orally administered 180mg of VB6 every day for 20 weeks. Patients in groups II and III, whose serum ferritin levels were far below normal (due to suspected iron deficiency anemia), were either administered iron alone (intravenous administration of 40mg of iron for 12 consecutive dialysis treatments, for 4 weeks--group II) or both iron and VB6 (group III). There was significant improvement in the hematocrit, mean corpsular volume (MCV), and mean corpsular hemoglobin (MCH) in group I patients supporting the contention that this group of patients had pyridoxine responsive anemia (PRA). The number of sideroblasts in bone marrow in these patients, however, was significantly low when compared to that of the normal subjects. In addition, the combined therapy with iron and VB6 led to the longer-sustained improvement in hematocrit in patients with suspected iron deficiency anemia (group III) when compared to those treated with iron alone (group II).(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical approaches to the anterior communicating artery aneurysm and their results

In the past 12 years, 102 cases of anterior communicating artery aneurysm have been operated upon in our institution. Two basic microsurgical approaches (pterional and interhemispheric) were used. The combined pterional and interhemispheric approach was performed in a few cases. The rational for each surgical approach is discussed in relation to anatomical factors such as the height of the aneurysm neck, the side of dominance of A1, the relationship between the bilateral proximal parts of A2s, and the projection of the aneurysm. The final outcome was correlated to the preoperative clinical grading and timing of surgery. The overall results were as follows; 82.4% good, 5.9% fair, 4.9% poor, and 6.8% mortality rate. The operative results for pterional and interhemispheric approach were comparable with each other. In the combined approach, we got poorer results which could be related to excessive brain retraction and unfavourable clinical grading.

Angiographic differentiation of carotid cave aneurysms from ventral paraclinoid carotid aneurysms of Nutik type

Although it appears that carotid cave and ventral paraclinoid carotid aneurysms are different types of internal carotid artery (ICA) aneurysms, it can be difficult to differentiate the two on the basis of angiograms, because their locations are very close. The purpose of this study was to review the angiographic findings in 21 cases with carotid cave aneurysms and 7 cases with ventral paraclinoid carotid aneurysms of less than 15 mm in diameter (Nutik aneurysm) operated upon in our unit during the last 14 years, and to discuss the difference between the two groups. The results showed that in the anteroposterior view of the angiogram, all carotid cave aneurysms projected medially in semicircular, or berry shape, while only slight medial projection was noted in 3 cases with Nutik aneurysm, the remainder being superimposed on the ICA. In the lateral view of the angiogram, we found that in 6 of the 7 Nutik aneurysms there was a space between the axilla (area inside the genu of the ICA) and the anterior or anteroinferior wall of the aneurysm. This space was absent in all carotid cave aneurysms since these aneurysms projected inferoposteriorly from the genu of the ICA. It is concluded that predominant medial projection in the anteroposterior view and absence of space in the lateral view are two characteristic features of carotid cave aneurysms which can be used to differentiate them from most Nutik aneurysms.

Surgical treatment of hemodialysis-related shoulder arthropathy

Thirteen patients with hemodialysis-related shoulder arthropathy were treated either with arthroscopic synovectomy or with open surgery. Arthroscopic synovectomy was performed in eight patients who had shoulder pain, shoulder immobility or both but did not have cystic bone lesions. The therapy was effective for pain relief and improvement of shoulder function for six months but in 12 months the shoulder pain reappeared in most of the patients. Open surgery was done in 5 patients who, in addition to shoulder pain and immobility, had humeral head bone cysts. Resection of the deposited mass on the biceps tendon sheath, of hypertrophied synovium and bursa as well as curettage of cysts and calcium hydroxyapatite ceramic implantation were performed. The therapy was effective for pain relief throughout the follow-up period (12 months). No adverse effects were noted for either procedure. Resected specimens of the synovia contained amyloid as indicated by a positive Congo-red stain by light microscopy and the presence of amyloid fibrils by electron microscopy. Deposition of amyloid in the biceps tendon sheath, synovium and bursa and invasion of the humeral head by amyloid were observed upon open surgery. The results suggest that the resection of deposited material induces the improvement of the shoulder arthropathy.

A comparative study of atherosclerosis and osteopenia in elderly and young hemodialysis patients

The effects of aging on atherosclerosis and osteopenia in hemodialysis patients were investigated. Eighty patients on maintenance hemodialysis were subdivided according to age into old (greater than or equal to 65 years old, N = 40) and young (less than 65 years old, N = 40). Biochemical, radiologic, and biophysical studies were performed in each patient to assess the degree of atherosclerosis and osteopenia. Compared to age-matched controls, patients in the old group exhibited a significantly higher aortic pulse wave velocity (PWV), and old female patients had a significantly lower bone mineral content/bone width (BMC/W). Elderly patients also had a significantly higher aortic PWV and higher grade of aortic calcification as assessed radiologically; in contrast, the BMC/W was lower. Concerning sex differences, elderly male patients had the highest average grade of aortic calcification, the lowest serum Pi, [Ca] x [Pi], and immunoreactive parathyroid hormone concentrations, while elderly female patients had the lowest BMC/W and highest incidence of osteopenia. These observations suggest that elderly male hemodialysis patients are more prone to develop atherosclerosis and elderly female hemodialysis patients to develop advanced osteopenia.

[A case of disproportionately large communicating fourth ventricle (DLCFV) combined with syringomyelia and Chiari malformation]

We report a rare case of disproportionately large communicating fourth ventricle (DLCFV) combined with syringomyelia and Chiari malformation. The case was a 27-year-old male who underwent ventriculoperitoneal (V-P) shunt on the right side for hydrocephalus caused by traumatic intracerebral and intraventricular hemorrhage. One month later, he became somnolent with posterior fossa symptoms (nausea, vomiting and nystagmus). CT scan demonstrated enlarged fourth ventricle, which was diagnosed as DLCFV because the ventriculogram revealed patency of the aqueduct. One and half month later a second V-P shunt was made on the left side to increase the shunt flow. He became ambulatory with a cane, although the fourth ventricle remained moderately dilated on CT scan. Two months after the additional V-P shunt, he slipped and hit the occiput and immediately became tetraparetic. The patient was treated conservatively under the diagnosis of central spinal cord injury. The MRI taken 2 months after the accident revealed Chiari malformation (type 1), syringomyelia and a dilated fourth ventricle which was compressing the brainstem. After the fourth ventriculoperitoneal (FV-P) shunt, the tetraparesis transiently improved but then again worsened. On the CT scan the syrinx did non change in size, while the size of the fourth ventricle became normal. After syringoperitoneal (S-P) shunt the patient showed a moderate improvement of tetraparesis. Unfortunately he suffered appendicitis complicated with peritonitis and all the shunts were immediately changed to external drainage. However, the patient developed meningitis and became paraplegic. The motor function of the upper extremities slightly improved by aspiration of fluid via the external drainage system from the syrinx.(ABSTRACT TRUNCATED AT 250 WORDS)

[Porphyria cutanea tarda in a chronic hemodialysis patient]

After 6 months on hemodialysis, a 58-year-old male patient with diabetes developed photosensitive bullous dermatosis on his hands and face. There was no evidence of liver diseases although the patient had a history of excessive alcohol consumption. He was suspected to have iron overload in the liver. Analysis of porphyrins in plasma, hemofiltrate, urine and feces by high performance liquid chromatography revealed significantly high levels in these samples with a porphyrin profiles which is consistent with porphyria cutanea tarda. The fluorometric assays of plasma also disclosed an elevated plasma porphyrin level. And it seemed that there were correlation between the fluctuation of vesicle formation, serum ferritin level and plasma porphyrin level. Small volume plasma exchange temporarily reduced the plasma porphyrin level and prevented vesicle formation.

New CT-guided stereotactic apparatus and clinical experience with intracerebral hematomas

The conventional Sugita stereotactic frame has been improved to perform CT-guided stereotactic surgery both in the CT and operating rooms. The development of our instrument and the software of the scanners' computer are presented. Newly designed equipment produced almost no artifacts on the CT image. Using the improved stereotactic frame, we have operated upon 44 intracerebral hematomas in the CT room. More than 80% of the cases had satisfactory results. Two complications were encountered, and 1 patient died from pneumonia. Our initial experience of the pre- and postoperative cerebral blood flow measurement with 133Xe inhalation method and single photon emission CT is described.

[Cerebellar hemangioblastoma developing after nephrectomy for renal cell carcinoma]

Cerebellar hemangioblastomas are known to be occasionally associated with abdominal tumors such as renal cyst and renal cell carcinoma. But most of the abdominal tumors reported are clinically silent and usually diagnosed after the hemangioblastomas have been found in the central nervous system. We report a rare case in which a renal cell carcinoma preceeded in its onset of symptoms 4 years to a cerebellar hemangioblastoma. A 56-year-old female underwent left nephrectomy because of a left renal cell carcinoma at the age of 49. About 4 years after the nephrectomy, she developed signs and symptoms of intracranial hypertension and was operated on for a cerebellar tumor which was histologically diagnosed as hemangioblastoma. Her family history was non-contributory. Four years later, recurrence of the cerebellar tumor was found on the CT scan and abdominal studies were negative except for a suspected parapelvic cyst in the right kidney on abdominal ultrasonography. Subtotal removal of the cerebellar hemangioblastoma was performed followed by irradiation.