Borg's exertion scale did not coincide with ventilatory anaerobic threshold in atrial fibrillation patients with restored sinus rhythm after ablation

The determination of precise exercise intensity is essential for effective exercise rehabilitation. The Borg rating of perceived exertion category ratio (CR) scale is utilized to prescribe an appropriate level of exertion intensity. A Borg CR of approximately 13 coincides with the ventilatory aerobic threshold (VAT). Patients with atrial fibrillation (AF) exhibit various symptoms. We hypothesized that the workload at Borg CR13 (Borg CR13-Watt) differs from the workload at the VAT level (VAT-Watt) in AF patients with restored sinus rhythm (SR) following ablation. Accordingly, the relationship between Borg CR13-Watt and VAT-Watt was studied in patients with restored SR. Cardiopulmonary exercise testing (CPET) was performed at 101±88 days after ablation in 150 patients using a bicycle ergometer. No adverse events were observed during CPET. Borg CR13-Watt was significantly higher than VAT-Watt (67.2±27.8 Watt vs. 54.7±17.6 Watt, P<0.0001). Borg CR13-Watt showed significant linear regression with VAT-Watt (regression coefficient, 0.49, P<0.01; correlation coefficient, 0.80, P<0.01). Higher Borg CR13-Watt was associated with greater differences between Borg CR13-Watt and VAT-Watt (ΔWatt). The Bland-Altman plot showed nonconcordance between the two. Male sex, use of antiarrhythmic drugs, and smoking had contributed to the increased ΔWatt. Duration from ablation to time of CPET did not correlate with ΔWatt. Therefore, Borg CR13-Watt did not coincide with VAT-Watt in patients with restored SR. Higher Borg CR13-Watt was associated with greater ΔWatt. Prescribing exertion intensity as determined solely by perceived exertion is inadequate. CPET is required to determine the precise exercise intensity in AF patients with restored SR after ablation.

Reproducibility of cardiopulmonary exercise testing between one after and 1-3 weeks after elective percutaneous coronary intervention

Prompt prescription and early initiation of exercise training are essential for patients undergoing elective percutaneous coronary intervention (PCI). We hypothesized that cardiopulmonary exercise testing (CPET) parameters determined the day after elective PCI during hospitalization would not differ from those obtained 1-3 weeks post-PCI in patients with stable coronary heart disease (CHD). CPET was performed the day after and 1-3 weeks (13±4.6; 7-21 days) after PCI. CPET was performed with a bicycle ergometer up to the ventilatory aerobic threshold (VAT) on the day after PCI. Symptom-limited CPET was conducted 1-3 weeks after PCI. No complications arose from the tests. There were no significant differences in %VAT (next day: 88.6±16.7 vs. 1-3 weeks later: 91.4%±18.7%), the workload at the VAT (51.8±11.0 W vs. 52.9± 11.6 W), heart rate (HR) at the VAT (95.3±105 beats/min vs. 94.1±11.3 beats/min), or metabolic equivalent (METs) at the VAT (3.69±0.69 vs. 3.84±0.78) between the two sessions. The slope of linear regression for two repeated measurements was close to 1 (%VAT, 1.02; workload at the VAT, 0.95; METs at the VAT, 1.03), except for HR (0.70). Bland-Altman plots revealed the reproducibility of all four CPET measurements between the two sessions. In conclusion, CPET up to the VAT can be performed safely 1-day post-PCI in patients with stable CHD. CPET parameters do not significantly differ between testing performed the day after and 1-3 weeks after PCI. Next-day CPET during hospitalization after PCI may enable prompt exercise prescription without the need for another CPET 1-3 weeks later.

Optimal prevention method of phrenic nerve injury in superior vena cava isolation: efficacy of high-power, short-duration radiofrequency energy application on the risk points

BACKGROUND OR PURPOSE

Superior vena cava isolation (SVCI) is widely performed adjunctively to atrial fibrillation (AF) ablation. Right phrenic nerve injury (PNI) is a complication of this procedure. The purpose of the study is to determine the optimal PNI prevention method in SVCI.

METHODS

A total of 1656 patients who underwent SVCI between 2009 and 2022 were retrospectively examined. PNI was diagnosed based on the diaphragm position and movement in the upright position on chest radiographs before and after SVCI.

RESULTS

With the introduction of various PN monitoring systems over the years, the incidence of SVCI-associated PNI has decreased. However, complete PNI avoidance has not been achieved. PNI incidence according to fluoroscopy-guided PN monitoring, high-output pace-guided, compound motor action potential-guided, and 3-dimensional electro-anatomical mapping (EAM) systems was 8.1% (38/467), 2.7% (13/476), 2.4% (4/130), and 2.8% (11/389), respectively. However, a high-power, short-duration (50 W/7 s) radiofrequency (RF) energy application only on PNI risk points tagged by a 3-dimensional EAM system completely avoids PNI (0%; 0 /160 since April 2021). PNI showed no symptoms and recovered within an average of 188 days post-SVCI, except for a few patients who required > 1 year.

CONCLUSIONS

Although PNI incidence decreased annually with the introduction of various monitoring systems, these monitoring systems did not prevent PNI completely. Most notably, the delivery of a high-power, short-duration RF energy only on risk points tagged by EAM prevented PNI completely. PNI recovered in all patients. The application of higher-power, shorter-duration RF energy on risk points tagged by EAM appears to be an optimal PNI prevention maneuver.

Small solitary atrial fractionated electrogram zone as a novel ablation target for persistent atrial fibrillation

INTRODUCTION

Various adjunctive approaches to pulmonary vein isolation (PVI) have been attempted for persistent atrial fibrillation (perAF) and longstanding persistent AF (ls-perAF). We aimed to identify the novel zones responsible for perpetuation of AF.

METHODS

To identify novel zones acting as a source of perAF and ls-perAF after PVI/re-PVI, we performed fractionation mapping in 258 consecutive patients with perAF (n = 207) and ls-perAF (n = 51) in whom PVI/re-PVI failed to restore sinus rhythm.

RESULTS

In 15 patients with perAF (5.8%: 15/258), fractionation mapping identified a small solitary zone (<1 cm² ) with high-frequency and irregular waves, showing fractionated electrograms (EGM). We defined this zone as the small solitary atrial fractionated EGM (SAFE) zone. The small SAFE zone was surrounded characteristically by a homogeneous area showing relatively organized activation with nonrapid and nonfractionated waves. Only one small SAFE zone was detected in each patient. This characteristic electrical phenomenon was observed stably during the procedure until ablation. AF duration, (defined as the duration between initial detection of AF and the current ablation) was longer in patients with the small SAFE zone than in those without (median, [25 and 75 percentiles]; 5.0 [3.5, 7.0] vs. 1.1 [1.0, 4.0] years, p = .0008). Longer AF cycle length was observed in patients with the small SAFE zone than in those without. The ablation of the small SAFE zone terminated AF in all 15 patients without any need for other ablations. AF/atrial tachycardia-free rate at follow-up was 93% (14/15) at 6 months, 87% (13/15) at 1 year, and 60% (9/15) at 2 years.

CONCLUSIONS

Using fractionation mapping, this study identified a small SAFE zone surrounded characteristically by a homogeneous, relatively organized, low-excitability EGM lesion. The ablation of the small SAFE zone terminated AF in all patients, demonstrating it as a substrate for perpetuated AF. Our findings provide novel ablation targets in perAF patients with prolonged AF duration. Further studies to confirm the present results are warranted.

Rates of atrial flutter occurrence and cavotricuspid isthmus reconduction after prophylactic isthmus ablation performed during atrial fibrillation ablation: a clinical study, review, and comparison with previous findings

PURPOSE

Based on the high rate of coexisting atrial fibrillation (AF) and atrial flutter (AFL), prophylactic cavotricuspid isthmus ablation (CTIA) adjunctive to AF ablation has recently been attempted in patients with AF and without AFL. The present study aimed to determine the rates of AFL occurrence and CTI reconduction after performing CTI ablation adjunctive to AF ablation.

METHODS

We analyzed the data of 3833 consecutive patients with AF, who underwent prophylactic CTIA with AF ablation between 2009 and 2020.

RESULTS

In all patients, CTIA and AF ablations were successful. Clinical AFL occurred in seven patients (0.18%, 7/3,833), and the observed rate was lower than those reported for cases of AF ablation without CTIA and for those of CTIA for pure AFL. A second ablation was needed in 745 patients at a median of 253 days (25 and 75 percentiles, 116 and 775 days) after the first ablation. In 12.1% (90/745) of the patients, CTI reconduction was observed. The reconduction rate was lower than that previously reported for CTIA for pure AFL.

CONCLUSIONS

The present retrospective study found acceptably low rates of clinical AFL occurrence and CTI reconduction following prophylactic CTIA performed with AF ablation, which was supported by the findings obtained after performing a comparison of the rates with those of other ablations (AF ablation only and CTIA for pure AFL). Considering the high correlation between AF and AFL, the present study provided information regarding the efficacy of adjunctive CTIA.

Efficacy of an Adjunctive Electrophysiological Test-Guided Left Atrial Posterior Wall Isolation in Persistent Atrial Fibrillation Without a Left Atrial Low-Voltage Area

BACKGROUND

Electrical remodeling precedes structural remodeling. In adjunctive left atrial (LA) low-voltage area (LVA) ablation to pulmonary vein isolation of atrial fibrillation (AF), LA areas without LVA have not been targeted for ablation. We studied the effect of adjunctive LA posterior wall isolation (PWI) on persistent AF without LA-LVA according to electrophysiological testing (EP test).

METHODS

We examined consecutive patients with persistent AF with (n=33) and without (n=111) LA-LVA. Patients without LA-LVA were randomly assigned to EP test-guided (n=57) and control (n=54) groups. In the EP test-guided group, an adjunctive PWI was performed in those with positive results (PWI subgroup; n=24), but not in those with negative results (n=33). The criteria for positive EP tests were an effective refractory period ≤180 ms, effective refractory period>20 ms shorter than the other sites, and/or induction of AF/atrial tachycardia (AT) during measurements. LVA ablation was performed in the patients with LA-LVA.

RESULTS

During the follow-up period (62±33 weeks), the EP test-guided group had significantly lower recurrence rates (19%,11/57 versus 41%, 22/54, P=0.012) and higher Kaplan-Meier AF/AT-free survival curve rates than the control group (P=0.01). No significant differences in the recurrence and AF/AT-free survival curve rates between the PWI (positive EP test) and non-PWI (negative EP test) subgroups were observed. Therefore, PWI for positive EP tests reduced the AF/AT recurrence in the EP test-guided group. A stepwise Cox proportional hazard analyses identified EP test-guided ablation as a factor reducing the recurrence rate. The recurrence rates in the LA-LVA ablation group and EP test-guided group were similar.

CONCLUSIONS

This pilot study proposed that an EP test-guided adjunctive PWI of persistent AF without LA-LVA potentially reduced AF/AT recurrences. The results suggest that there is an AF substrate in the LA with altered electrophysiological function even when there is no LA-LVA. Graphic Abstract: A graphic abstract is available for this article.

Correlation of the peak oxygen consumption and ventilatory aerobic threshold by cardiopulmonary exercise testing with atrial fibrillation recurrences after ablation in patients with paroxysmal atrial fibrillation

Background

The cardiopulmonary function is hypothesized to be associated with atrial fibrillation/atrial tachyarrhythmia (AF/AT) recurrence after AF ablation.

Purpose

To clarify the relationship between the cardiopulmonary function after successful ablation and AF/AT recurrence.

Methods

We examined 31 patients with paroxysmal AF who underwent AF ablation. Cardiopulmonary exercise testing (CPET) was performed at 1month after the ablation. A continuously increasing loading method on a bicycle ergometer was employed for the CPET.

Results

No adverse events, including AF/AT recurrence, occurred during the CPET. Among 31 patients, AT/AF recurrence was observed in seven (23%). The ventilatory anaerobic threshold (VAT) and peak oxygen consumption (VO2) were significantly higher in patients without AF/AT recurrence than in those with AT/AF recurrences (peak VO2 23.6 ± 5.7 vs 17.2 ± 4.1 mL/kg/min; VAT, 16.7 ± 2.8 vs 13.8 ± 2.7 mL/min/kg). The areas under the receiver operating characteristic curve for the peak VO2 and VAT were 0.786 (P < .01) and 0.789(P < .01), respectively. Both indices had a sensitivity of 70%–80% and specificity of 70%–80% for predicting AT/AF recurrence. Similar results were obtained for the percent values of the predicted peak VO2 and VAT.

Conclusions

The present pilot study found that CPET can be performed safely at approximately 1 month after AF ablation. The peak VO2 and VAT were significantly associated with AT/AF recurrence. The peak VO2 and VAT were thought to provide helpful information regarding AT/AF recurrence.

Activated clotting time on the day of atrial fibrillation ablation for minimally interrupted and uninterrupted direct oral anticoagulation therapy: Sequential changes, differences among direct oral anticoagulants, and ablation safety outcomes

Background

Activated clotting time (ACT)–guided heparinization is used during atrial fibrillation (AF) ablation. Differences in sensitivity to ACT assays have been identified among different direct oral anticoagulants (DOACs).

Objective

We aimed to examine ACT just before ablation (pre‐ACT) for different ablation start times (9:00, 11:00, 13:00, or 15:00) and ablation safety outcomes in minimally interrupted (min‐Int) and uninterrupted (Unint) DOAC regimens and examine differences in pre‐ACT values among four DOACs.

Methods

Consecutive patients were randomized into the min‐Int (n = 307) or Unint (n = 277) groups. DOACs examined were apixaban, dabigatran, edoxaban, and rivaroxaban.

Results

No sequential changes in pre‐ACT values were observed for each DOAC used and for all four DOACs combined in the min‐Int and Unint groups. There was no meaningful difference in pre‐ACT at each ablation start time between the groups. Clinically significant differences in overall pre‐ACT were not obtained between the groups (138 ± 24 vs 142 ± 23 seconds). The pre‐ACT (baseline) value for dabigatran was on average 29 seconds higher than that for the other three DOACs. The min‐Int and Unint groups showed similar thromboembolic (0% vs 0%) and bleeding event rates (major, 1% vs 0%; all, 3.5% vs 2.5%).

Conclusion

The pre‐ACT did not show a sequential change in the min‐Int and Unint groups. No notable differences in the time‐dependent change in pre‐ACT between the groups were observed. Variations in baseline ACT suggest the need for moderate adjustment of ACT for adequate modification of heparin dose for the other three DOACs. Both regimens provided similar acceptable AF ablation safety outcomes.

Adjunctive interpulmonary isthmus ablation has no added effects on atrial fibrillation recurrence

Objective

Data on the efficacy of adjunctive interpulmonary isthmus ablation following completion of extensive encircling pulmonary vein isolation (EEPVI) on atrial fibrillation (AF) recurrence have still been insufficient. We aimed to compare the AF recurrence between EEPVI with and without adjunctive interpulmonary isthmus ablation.

Methods

We enrolled 200 consecutive patients with paroxysmal AF (first session) who underwent EEPVI with double-Lasso technique. Patients were prospectively randomised into two groups: EEPVI with (group 1) and without (group 2) adjunctive interpulmonary isthmus ablation.

Results

No differences were found in patients’ clinical and echocardiographic backgrounds, including arrhythmia status, between the two groups. No differences were also observed in complications (two groin haematoma in both groups). All patients in both groups reached the EEPVI endpoint. The AF recurrence rate between groups 1 (32/100, 32%) and 2 (33/100, 33%; p=1.0) was quite similar during the follow-up period (45±5 months; 36–54 months). The two groups showed identical Kaplan-Meier AF-free curves (p=0.460; NS). Similar pulmonary vein (PV) reconnection incidence was observed in both groups during the second session. Durable isolation between the superior and inferior PVs was confirmed in 88% (21/27) of patients in group 1, indicating that interpulmonary isthmus ablation maintained a non-conducting state in a considerable number of patients. Nevertheless, AF recurrence was identical between the two groups.

Conclusion

The results of our study showed similar AF recurrence rates between the two groups, indicating that adjunctive interpulmonary isthmus ablation with EEPVI has no obvious effects on AF recurrence.

Eosinophil Cationic Protein Shows Survival Effect on H9c2 Cardiac Myoblast Cells with Enhanced Phosphorylation of ERK and Akt/GSK-3β under Oxidative Stress

Eosinophil cationic protein (ECP) is well known as a cationic protein contained in the basic granules of activated eosinophils. Recent studies have reported that ECP exhibits novel activities on various types of cells, including rat neonatal cardiomyocytes. Here we evaluated the effects of ECP on rat cardiac myoblast H9c2 cells. Our results showed that ECP enhanced the survival of the cells, in part by promoting the ERK and Akt/GSK-3β signaling pathways. ECP attenuated the cytotoxic effects of H2O2 on H9c2 cells as well as the production of reactive oxygen species, the number of apoptotic cells and caspase 3/7 activity in the cells. In conclusion, ECP activated the ERK and Akt/GSK-3β pathways, resulting in anti-oxidative effects on H9c2 cells that attenuated apoptosis.

Arterial stiffness determined according to the cardio-ankle vascular index is associated with paroxysmal atrial fibrillation: a cross-sectional study

BACKGROUND

Several lines of evidence suggest that atrial fibrillation (AF) may be a consequence of vascular disease. We investigated the relationship between cardio-ankle vascular index (CAVI), a new index of arterial stiffness, and the presence of paroxysmal AF (PAF).

METHODS AND RESULTS

181 outpatients (91 patients with PAF and 90 age- and gender-matched subjects without PAF) were analysed for their sinus rhythm. The CAVI was significantly higher in patients with PAF than in subjects without PAF (9.0±1.0 vs 8.7±0.8, p<0.01). In all subjects, the CAVI was significantly correlated with the left ventricular mass index (r=0.30, p<0.01), left atrial diameter (r=0.22, p<0.01), and augmentation index, a parameter of wave reflection (r=0.32, p<0.01), in addition to age, systolic blood pressure and pulse pressure. Logistic analysis demonstrated that the CAVI was independently associated with PAF even after adjustment for confounding factors. The adjusted OR of PAF was 1.8 for each unit increase in the CAVI (p=0.01).

CONCLUSIONS

Our finding suggests that increased arterial stiffness may be involved in the maintenance of AF.

Usefulness of dabigatran etexilate as periprocedural anticoagulation therapy for atrial fibrillation ablation

BACKGROUND

The usefulness of dabigatran etexilate for the prevention of stroke in patients with atrial fibrillation (AF) has been reported.

OBJECTIVES

In this study the efficacy and safety of dabigatran etexilate for anticoagulation for AF ablation were examined.

METHOD

Patients were divided into three groups: Group 1, interrupted warfarin bridged by heparin between pre- and post-ablation; Group 2, continuous warfarin therapy; and Group 3, dabigatran etexilate therapy. Anticoagulation therapy with warfarin or dabigatran etexilate was performed from 30 days before to at least 90 days after AF ablation. Dabigatran etexilate was administered at 110 or 150 mg twice daily, depending on renal function and age.

RESULTS

Patients' clinical characteristics, associated disorders, echocardiographic parameters and arrhythmia status were not different among the three groups. Procedural parameters such as procedural time and radiofrequency energy supply were also not different among the three groups. The dabigatran etexilate group and the warfarin groups had no embolic complications (stroke, cerebral transient ischaemic attack, deep venous thrombosis or pulmonary embolism). No pericardial tamponade was observed in the dabigatran etexilate group, while two patients in each of Group 1 (2/194, 1.0 %) and Group 2 (2/203, 0.98 %) developed cardiac tamponade, though the differences were not significant. Pericardial effusion and groin haematoma were observed in one patient each (1/105, 0.9 %) in the dabigatran etexilate group, and the incidences were not different from the warfarin group (Group 1: 4/194, 2.1 % and 2/194, 1.0 %; Group 2: 3/203, 1.5 % and 2/203, 1.0 %, respectively). As a whole, the safety outcomes did not differ among the three groups.

CONCLUSION

Dabigatran etexilate is an effective and safe anticoagulation therapy for AF ablation. Thus, dabigatran etexilate appears to be useful as an alternative anticoagulant therapy to warfarin for AF ablation.

A case report of acute myocardial infarction induced by coronary spasm. Intravascular findings

A 53-year-old male complaining of chest pain was admitted to our hospital with suspected acute myocardial infarction (AMI). Emergent coronary angiography (CAG) determined a totally occluded middle right coronary artery (RCA). Thrombus aspiration was conducted, followed by intravascular ultrasound (IVUS) imaging. Diffuse intima plus media thickness was identified at the obstruction site and a thrombus was observed proximally to the occlusion site on IVUS. Following isosorbide dinitrate (ISDN) administration, dilatation of the RCA was confirmed. IVUS study indicated the luminal dilatation was achieved by the release of the diffuse intima plus media thickening. Of note, plaque volume showed no significant difference after administration of ISDN at any vessel site. These results clearly show that luminal dilatation and vessel dilatation were achieved from the redistribution of plaque volume (intima plus media). A follow-up CAG showed no significant stenosis in the RCA. After a provocation test using methylergometrine maleate, the RCA was totally occluded at the very site of the initial event. The involvement of vasospasm as a cause of AMI in the present case was doubly confirmed with characteristic IVUS images of vasospasm in the acute phase and with a provocation test at follow-up.

Adaptive-servo ventilation combined with deep sedation is an effective strategy during pulmonary vein isolation

AIMS

Pulmonary vein isolation (PVI) by catheter ablation for atrial fibrillation (AF) requires suppression of patient restlessness by sufficient sedation in addition to maintaining stable respiration. We applied adaptive-servo ventilation (ASV) and examined the effects of ASV combined with deep propofol sedation on PVI using a NavX.

METHODS AND RESULTS

We analysed 75 paroxysmal AF (PAF) patients (62 ± 11 years; 53 men and 22 women) who underwent PVI for treatment of PAF using an ASV system combined with deep sedation (ASV group). Control patients included 75 consecutive PAF patients (62 ± 11 years; 51 men and 24 women) who underwent PVI just before introduction of the ASV system. Deep sedation was defined as a Ramsay sedation score of 6. The ASV group had a lower frequency of restless body movements compared with the control group during PVI (1.5 ± 0.7 vs. 7.8 ± 1.4 times, P < 0.01). The frequency of respiratory compensation and EnGuide alignment of catheter position by the NavX was lower in the ASV (4.2 ± 3.3 and 8.8 ± 7.1 times) than control group (7.1 ± 5.1 and 15.2 ± 10.0 times, P < 0.05 and <0.01, respectively). Consequently, significantly lower total electrical energy supply (48.7 ± 6.0 KJ) was required in the ASV than control group (64.5 ± 24.9 KJ, P < 0.01). Further, significantly shorter fluoroscopy and procedural times were observed in the ASV (28 ± 5 and 109 ± 25 min) than the control group (33 ± 6 and 141 ± 38 min, respectively, P < 0.01) and the AF recurrence rate was significantly lower in the ASV than the control group (12 vs. 25%, P < 0.01).

CONCLUSION

ASV combined with deep sedation is an effective strategy during PVI using the NavX in patients with PAF.

Olmesartan reduces arterial stiffness and serum adipocyte fatty acid-binding protein in hypertensive patients

Adipocyte fatty acid binding protein (A-FABP) has been reported to be involved in insulin resistance, lipid metabolism, and atherosclerosis; however, little is known about the effect of medication on the change in circulating A-FABP in human subjects. We evaluated the effects of angiotensin II type 1 receptor blocker (ARB) on arterial stiffness and its association with serum A-FABP in patients with hypertension. Thirty patients newly diagnosed with essential hypertension were treated with olmesartan (20 mg/day), an ARB, for 6 months. Serum levels of A-FABP and high-sensitivity C-reactive protein (hsCRP) were examined and the cardio-ankle vascular index (CAVI), which is a marker of arterial stiffness, was also determined. Serum A-FABP at baseline was significantly correlated with the body mass index (r = 0.45, P = 0.01), homeostasis model assessment as a marker of insulin resistance (r = 0.53, P < 0.01), and systolic blood pressure (r = 0.37, P = 0.047), and tended to be correlated with low-density lipoprotein cholesterol, triglyceride, and CAVI. Olmesartan treatment resulted in a significant decrease in CAVI, serum A-FABP levels, and hsCRP, besides a significant reduction of blood pressure. Multiple regression analysis revealed that the change in CAVI was independently correlated with the change in serum A-FABP. Olmesartan ameliorated arterial stiffness in patients with hypertension, which may be involved in the reduction of serum A-FABP.

Cardio-ankle vascular index is independently associated with the severity of coronary atherosclerosis and left ventricular function in patients with ischemic heart disease

AIM

The cardio-ankle vascular index (CAVI) has been proposed as a new noninvasive marker of arterial stiffness independent of blood pressure. We investigated the association of the CAVI with coronary atherosclerosis and left ventricular (LV) systolic and diastolic function in patients with ischemic heart disease (IHD).

METHODS

A total of 206 consecutive subjects undergoing coronary angiography were enrolled. CAVI measurement and echocardiography were performed simultaneously. Patients having significant coronary stenosis were classified into the IHD group.

RESULTS

CAVI in the IHD group (n=133) was significantly higher than in the non-IHD group(n=73)(9.1+/-1.3 vs. 8.7+/-1.2, p=0.02). In all IHD patients, CAVI was negatively correlated with LV ejection fraction (LVEF)(r=-0.31, p<0.01), LV mass index (r=0.24, p<0.01) and angiographic scores of coronary atherosclerosis. Stepwise regression analysis revealed that CAVI was independently associated with LVEF, along with a history of myocardial infarction, LV mass index, and left atrial diameter in all IHD patients (p<0.01). In the sub-analysis of IHD patients with preserved LVEF, CAVI was correlated with echocardiographic parameters regarding LV diastolic function. Multivariate analysis demonstrated that the increased CAVI was significantly associated with LV diastolic dysfunction in patients with preserved LVEF.

CONCLUSION

CAVI, a new parameter of aortic stiffness, was independently associated with LV systolic and diastolic function as well as coronary artery disease in IHD patients.

Association of new arterial stiffness parameter, the cardio-ankle vascular index, with left ventricular diastolic function

AIM

Pulse wave velocity has been used as an index of aortic stiffness. Recently, the cardio-ankle vascular index (CAVI), which reflects the stiffness of the aorta independently of blood pressure, has been developed. In this study, we analyzed the relationship between CAVI and left ventricular (LV) diastolic dysfunction.

METHODS

A total of 119 patients were referred for echocardiography to evaluate ventricular function. Patients with reduced systolic function were excluded. Patients were divided on the basis of normal or reduced LV diastolic function determined by echocardiography. CAVI was measured using an automatic waveform analyzer.

RESULTS

CAVI was significantly higher in patients with reduced LV diastolic function than those with normal LV diastolic function (9.0+/-1.1 and 8.5+/-1.1, p=0.009). Multiple linear regression analysis revealed that CAVI was independently associated with the ratio of peak early diastolic velocity to peak atrial diastolic velocity and left atrial diameter. When patients were classified on the basis of CAVI quartiles, multiple logistic regression analysis demonstrated that the highest quartile of CAVI showed an increased odds ratio for the presence of LV diastolic dysfunction.

CONCLUSION

The present study revealed that an increased CAVI was independently associated with LV diastolic dysfunction in patients with preserved systolic function.

Safety of and tolerance to adenosine infusion for myocardial perfusion single-photon emission computed tomography in a Japanese population

BACKGROUND

Adenosine has been available for use in myocardial perfusion single-photon emission computed tomography (SPECT) in Japan since 2005. The purpose of this study was to evaluate the safety of and tolerance to thallium-201 myocardial perfusion SPECT with intravenous adenosine infusion in Japanese patients with suspected coronary artery disease.

METHODS AND RESULTS

Two hundred and six consecutive patients who underwent an adenosine infusion (120 mug . kg(-1) . min(-1)) SPECT at Sumitomo Besshi Hospital (Niihama, Japan) were investigated. The effects of adenosine infusion were monitored for each patient. A coronary angiography was performed in 81 patients. Adenosine infusion significantly decreased blood pressure and increased heart rate. Adverse reactions were observed in 161 patients (78.2%). Most reactions were transient, disappearing soon after the termination of adenosine infusion. No serious adverse reactions, such as acute myocardial infarction or death, occurred. Adenosine infusion was terminated in 3 patients (1.5%) because of near syncope or sustained 2:1 atrioventricular block. Electrocardiographic changes occurred in 15 patients (7.3%). Self-assessed scoring after SPECT showed that the patients were very tolerant (74.6% of 177 patients) of adenosine infusion myocardial SPECT. The sensitivity and specificity were 75.0% and 69.7%, respectively.

CONCLUSIONS

Adenosine infusion myocardial SPECT is safe and well tolerated in the Japanese population, despite the frequent occurrence of minor adverse reactions.

Coronary pressure measurement to identify the lesion requiring percutaneous coronary intervention in equivocal tandem lesions

OBJECTIVES

No reliable methods are available for determining application of percutaneous coronary intervention for treatment of equivocal tandem lesions. We investigated whether coronary pressure measurement is useful for determining the lesion that requires percutaneous coronary intervention in tandem lesions.

METHODS

We measured coronary pressure in 72 consecutive patients with tandem lesions. Myocardial fractional flow reserve (FFRmyo) was obtained as the ratio of coronary pressure distal to the lesion/aortic pressure under maximal hyperemia. If the FFRmyo across the tandem lesions was >or=0.75, we deferred percutaneous coronary intervention for the lesion. When the tandem lesions showed FFRmyo<0.75, percutaneous coronary intervention was performed on the lesion that showed angiographically higher stenosis. When FFRmyo was <0.75 after one-lesion percutaneous coronary intervention, this intervention was carried out on the remaining lesion.

RESULTS

We deferred percutaneous coronary intervention for 26 patients (36.1%), and performed percutaneous coronary intervention in 46 patients (63.8%). We performed percutaneous coronary intervention for one lesion in 19 patients (26.4%) and for both lesions in 27 patients (37.5%). Among patients in whom percutaneous coronary intervention was deferred, only two patients (7.7%) required target lesion revascularization during the follow-up period. This rate was not higher than that in the 46 patients who underwent percutaneous coronary intervention for one or two lesions (six patients, 13.0%). Similarly, the target lesion revascularization in lesions with initially deferred percutaneous coronary intervention (5.6%, 4/71 lesions) was not higher than that in lesions with percutaneous coronary intervention (15.1%, 11/73 lesions). Major cardiac events, cardiac death and acute myocardial infarction, did not occur in patients with deferred percutaneous coronary intervention and in those with percutaneous coronary intervention during the follow-up period.

CONCLUSION

Our results clearly showed that coronary pressure measurement was clinically useful for identifying equivocal tandem lesions requiring percutaneous coronary intervention.

Changes in escape rhythms several years after radiofrequency ablation of the atrioventricular junction combined with pacemaker implantation

OBJECTIVE

Escape rhythm is thought to play a considerable role in protection against adverse outcome due to pacemaker malfunction. We studied the escape rhythms in 32 patients with supraventricular tachyarrhythmia refractory to medical therapy who underwent radiofrequency ablation of the atrioventricular junction combined with implantation of a pacemaker.

METHODS AND RESULTS

We performed the escape rhythm analysis immediately and 2.6 +/- 1.9 years after the radiofrequency ablation by decreasing the pacing rate. In the initial study, escape rhythms (41 +/- 8 beats/min) were documented in 20 patients (63%). Non-cardiac death occurred in 3 patients with escape rhythm, and cardiac death occurred in I patient without escape rhythm. In the follow-up study, escape rhythms were detected in 22 of 28 patients (79%). Escape rhythm had developed in 6 (55%) of 11 patients who were without escape rhythm initially, while escape rhythm disappeared in 1 of 17 (5.9%) patients who had escape rhythm initially. The changes in escape rhythm were not related to QRS width of the intrinsic beat. There was no correlation between the number of radiofrequency applications or the ratio between atrial and ventricular electrocardiogram voltages of radiofrequency applications and the development of escape rhythms.

CONCLUSIONS

The present long-term follow-up study demonstrated that the emergence of an escape rhythm increased several years after ablation, but was unrelated to procedural factors. There are, however, certain patients in whom the disappearance of escape rhythms occur. The evaluation of escape rhythms is thus necessary to determine the risk associated with pacemaker failure.

Nicorandil reduces the incidence of minor cardiac marker elevation after coronary stenting

BACKGROUND

Minor cardiac marker elevation after percutaneous coronary intervention has long-term prognostic significance. We examined whether nicorandil, a nicotinamide-nitrate ester, reduces the incidence of minor cardiac marker elevation after coronary stenting.

METHODS

Patients (n=192) undergoing coronary stenting were randomly assigned to receive nicorandil (nicorandil group, n=91) or vehicle (control group, n=101). Nicorandil (2 mug/kg/min, intravenously) was administered immediately after the patients were transferred into the catheterization laboratory and continued for 6 h. We measured the serum concentrations of creatine kinase isoenzyme MB (CK-MB) before, immediately after, and 6, 12, and 24 h after the procedure, and those of cardiac troponin T (cTnT) 24 h after the procedure.

RESULTS

There was no significant difference in clinical background between the 2 groups. The nicorandil group showed a significantly lower incidence of CK-MB elevation (>1x upper limit of control range, 20 IU/l) than the control group (8.8% vs 21.8%, p<0.05). The levels of serum CK-MB in the nicorandil group were significantly lower than those in the control group (13.4+/-5.7 vs 16.5+/-9.7 IU/l, p<0.01). Similarly, the nicorandil group showed a significantly lower incidence of cTnT elevation [>1x (0.1 ng/ml) or >2x (0.2 ng/ml)] upper limit of control range than the control group (14.3% vs 26.7%, p<0.05, or 7.7% vs 17.8%, p<0.05). Serum cTnT levels were also significantly lower in the nicorandil group than in the control group (0.05+/-0.10 vs 0.15+/-0.36 ng/ml, p<0.05).

CONCLUSIONS

The results demonstrated that nicorandil reduces minor cardiac marker elevation after coronary stenting.

Coronary pressure measurement to determine treatment strategy for equivocal left main coronary artery lesions

It is often hard to select a treatment strategy for equivocal left main coronary artery (LMCA) disease. We investigated the usefulness of coronary pressure (CP) measurement for determining the treatment strategy in intermediate LMCA disease. We measured CP in 15 consecutive patients with equivocal LMCA disease (age 67.6 +/- 7.5 years, 14 males). Myocardial fractional flow reserve (FFRmyo) was obtained as the ratio of CP distal to the lesion/aortic pressure under maximal coronary dilation. Patients with FFRmyo > or = 0.75 and <0.75 received medical therapy and coronary artery bypass grafting (CABG), respectively, and were followed up for 32.5 +/- 9.7 (20-47) months. Eight patients received medical therapy and 7 patients underwent CABG in accordance with the FFRmyo criteria noted above. FFRmyo of the LMCA was 0.91 +/- 0.01 and 0.61 +/- 0.03 in patients who received medical and surgical therapy, respectively. Neither reference vessel diameter, minimal lumen diameter, nor percent diameter stenosis was significantly different between patients who received medical and surgical therapy. During the follow-up period, no patients with medical therapy showed symptoms due to the LMCA lesion. Similarly, 5 of 7 patients with CABG showed improvement of symptoms and the remaining 2 patients were hospitalized with congestive heart failure. No cardiac death was recorded in the patients with medical or surgical therapy. In conclusion, the present results clearly demonstrated that CP is clinically useful for determining the treatment strategy for equivocal LMCA lesions but coronary angiography is not.

Significant correlation of recruitable coronary collateral blood flow determined by coronary wedge pressure with ST-segment elevation during coronary occlusion

OBJECTIVES

Quantitative assessment of coronary collateral blood flow can be archived by measuring coronary pressure. We studied the relationships between recruitable coronary collateral blood flow and electrocardiographic changes during percutaneous coronary intervention (PCI).

METHODS

We measured coronary pressure during coronary occlusion with PCI in 119 patients with left anterior descending coronary artery stenosis. During balloon inflation, the electrocardiogram was continuously recorded. The ST-segment elevation in the most elevated lead was defined as MaxST and the sum of the maximal ST elevation in leads V2-V4 was defined as sumST. Fractional collateral flow (Qc/Q(N)) was calculated as the coronary wedge pressure divided by the mean aortic pressure. Myocardial ischemia was defined as an ST-segment shift >0.1 mV in any of the V2, V3 or V4 leads.

RESULTS

A significant relationship between Qc/Q(N) and MaxST was observed (r=-0.455, P<0.0001). Similarly, Qc/Q(N) was significantly correlated with sumST (r=-0.477, P<0.0001). The receiver operating characteristic curve showed that a cut-off value of 0.27 for Qc/Q(N), with sensitivity of 71.4% and specificity of 76.2%, was an indicator of electrophysiologically sufficient recruitable coronary collateral blood flow for prevention of ischemia during coronary obstruction. Qc/Q(N) values during the first, second, third and fourth inflation were not significantly different.

CONCLUSIONS

Qc/Q(N) could be clinically useful for determining whether there is electrophysiologically sufficient recruitable coronary collateral blood flow for prevention of ischemia during coronary obstruction. Repeat transient coronary occlusion during PCI did not lead to increased collateral blood flow.

Minimally invasive management of the third ventricle glioma in a patient without hydrocephalus: neurofiberscopic biopsy followed by gamma knife radiosurgery

There is usually concern that ventricular enlargement is necessary for safe neuroendoscopic procedures. However, newly developed models of neurofiberscopes with a small outer diameter can be effectively used even in patients without ventriculomegaly. We present the case of a successful neurofiberscopic biopsy of a third ventricle anaplastic astrocytoma in a previously shunted patient without hydrocephalus. Subsequent gamma knife radiosurgery led to complete disappearance of the tumor. It seems that presence of collapsed ventricles, and even symptoms consistent with the slit ventricle syndrome, should not be considered as contraindications for neurofiberscopic surgery when brain compliance is sufficiently preserved. The latter should be considered as the key point of safe endoscopic manipulations. The combination of the neuroendoscopy and stereotactic radiosurgery provides wide possibilities for minimally invasive management of selected intracranial tumors.

Circulating white blood cell count correlates with left ventricular indices independently of the extent of risk area for myocardial infarction after successful reperfusion

OBJECTIVE

To test the hypothesis that the circulating white blood cell (WBC) and neutrophil counts are related to left ventricular (LV) indices in patients with the same risk area for acute myocardial infarction (AMI), we examined 100 consecutive AMI patients who had the culprit lesion at segment 6 according to the American Heart Association classification and who underwent successful direct coronary angioplasty.

METHODS AND RESULTS

The LV ejection fraction (LVEF), end-systolic volume (LVESVI) and end-diastolic volume index (LVEDVI) were obtained by left ventriculography performed 4 weeks after AMI onset. Univariate analysis disclosed that the counts of WBC and neutrophils on admission, and the maximal WBC count correlated negatively with LVEF (r = -0.46, p < 0.001; r = -0.54, p < 0.001 and r = -0.40, p < 0.001, respectively) and positively with LVESVI (r = 0.43, p < 0.001; r = 0.55, p < 0.001, and r = 0.30, p < 0.01, respectively). The counts of WBC and neutrophils on admission also correlated with LVEDVI (r = 0.28, p < 0.01 and r = 0.41, p < 0.001, respectively). Multivariate analysis with other clinical and angiographic factors revealed that the counts of WBC and neutrophils on admission correlated with LVEF (partial correlation coefficient, r = -0.37, p < 0.001 and r = -0.52, p < 0.001, respectively), with LVESVI (r = 0.34, p < 0.01 and r = 0.56, p < 0.001, respectively) and with LVEDVI (r = 0.28, p < 0.01 and r = 0.44, p < 0.001, respectively). The maximal WBC count also correlated with LVEF and LVESVI (r = -0.40, p < 0.001 and r = 0.21, p < 0.05, respectively).

CONCLUSION

The present study revealed that the circulating WBC count correlated with function and volume of the successfully reperfused LV after AMI in patients with the same risk area for AMI, indicating that the WBC count needs to be taken into consideration as an independent factor affecting the LV indices.

Coronary Flow Reserve after Coronary Intervention is Similar in Patients with Preserved Viability in Previous Myocardial Infarction and in Those with Angina Pectoris

The relationship between coronary flow reserve (CFR) and viability in the infarcted myocardium has not been fully clarified. We measured coronary blood flow velocity immediately after coronary intervention (with percutaneous transluminal coronary angioplasty [PTCA] or stenting) in 38 patients with previous myocardial infarction and preserved viability and 48 with angina pectoris. CFR was calculated and was similar between the two patient groups. No differences in the incidence of post-intervention CFR > 2.0 were detected; there were no differences in postintervention CFR between patients with preserved myocardial viability and those with angina pectoris who underwent PTCA. Coronary stenting reduced the percentage diameter stenosis in both groups compared with PTCA and slightly increased the post-intervention CFR. No differences were, however, detected in postintervention CFR between patients with preserved myocardial viability and those with angina pectoris who underwent additional stenting. These results reveal that in patients with preserved myocardial viability, post-intervention CFR was restored to values similar to those in patients with angina pectoris.

Flexible endoscope-assisted endonasal transsphenoidal surgery for pituitary tumors

We have performed rigid endoscope-assisted endonasal transsphenoidal microsurgeries for pituitary tumors in 230 patients. Recently, we further introduced the use of a flexible endoscope to inspect the tumor bed and suprasellar structures more extensively. We report our experience with the flexible endoscope in endonasal transsphenoidal surgery for pituitary tumors. The endoscopes were used to complement the microscope in visualization. The flexible endoscopes were used in 34 recent cases with suprasellar and/or lateral tumor extension. During or after removal of the main tumor bulk, the flexible endoscope together with a rigid endoscope was used to inspect the tumor cavity, especially at the blind spot of the microscope. Despite limited resolving power, in all the 34 cases the flexible endoscope was a highly efficient tool permitting extensive visualization of almost the whole surgical area, even in narrow surgical fields and spaces not visible with an operating microscope or a rigid endoscope, and allowing continuous change of viewing angle. The residual tumor situated laterally or in the suprasellar areas that could not be reached and was impossible to remove by a rigid endoscope could be dissected and extirpated under a flexible endoscope using grasping forceps in 5 patients with pituitary adenoma and all the craniopharyngioma cases. The flexible endoscope may be more efficient in the lateral and suprasellar areas than the rigid endoscope in compensating for the narrow surgical field in endonasal pituitary surgery, despite its limited resolving power. Surgeons should make the best use of the advantages of each instrument.

Ectopic clival craniopharyngioma

Ectopic craniopharyngioma is a rare entity. The authors present a very rare case of an ectopic clival craniopharyngioma completely separate from the sella turcica.A 44-year old woman presented with abducens palsy. A MR imaging study and a CT scan revealed a cystic clival lesion separate from the sella turcica. Surgical resection was performed successfully with flexible endoscope-assisted procedure using an endonasal transsphenoidal approach. No evidence of involvement of the sellar region was found according to radiological, intra-operative, and clinical findings.A review of the literature revealed no other such cases. The discussion includes the formation of craniopharyngioma from the ectopic Rathke's pouch remnants and the surgical approach for clival lesions. We believe that our approach provides good results with minimal invasiveness for some clival lesions.

Application of flexible neuroendoscopes to intracerebroventricular arachnoid cysts in children: use of videoscopes

Videoscopes used in other parts of the human body are potential tools for neuroendoscopy as long as they are slim enough, because they provide exceptionally high resolution images. We describe the application of flexible videoscopes and neuroendoscopes developed in Japan to intraventricular arachnoid cysts in children. Thirty-eight children with middle fossa arachnoid cysts were treated either by conventional cystoperitoneal shunting operations (n = 28) or by neuroendoscopes (n = 10). Neuroendoscopic operations such as cyst fenestration were highly useful, eliminating the need for open surgery for cyst excision/fenestration or cystoperitoneal shunting operations in all of the patients during a mean follow-up period of 17.7 months. Statistically highly significant reductions were observed in the major complications (p < 0.0001 by chi(2)-test) because shunting operations were inevitably accompanied by shunt malfunction, infection, or dependence. Compared to the traditional neuroendoscopes, our slim videoscopes provided outstanding image quality, allowing for more comprehensive examination and treatment while minimizing operative trauma.

Intraventricular hemorrhage in neonates: endoscopic findings and treatment by the use of our newly developed Yamadori-type 8 ventriculoscope

Profound intraventricular hemorrhage (IVH) has devastating effects on neonates, leading to significant neurodevelopmental morbidity. We have developed a flexible fiberoptic ventriculoscope (Yamadori-type 8), which has a conspicuously high resolving power and is equipped with a bipolar coagulator and a working channel for irrigation. Four neonates with IVH were examined and treated for the first time using the flexible ventriculoscope. The patients had grade III or IV IVH on computed tomography scans and received endoscopic operations three to four weeks after birth. In patients with IVH, fragments of old hematomas were observed as brown masses because of the presence of hemosiderin, a characteristic endoscopic finding. We have found, for the first time, IVH due to rupture of the varices of septal veins, which could be cauterized endoscopically. Hydrocephalus was relieved by irrigation, third ventriculostomy, coagulation of the choroid plexus, and adequate placement of ventriculoperitoneal shunting was performed endoscopically. The flexible ventriculofiberscope could be a useful modality for early treatment of IVH in neonates because of the minimal invasiveness. The pathogenesis of IVH should be reviewed to include septal vein varices as a possible cause of IVH.

Endoscopic treatment of hydrocephalus in children: a controlled study using newly developed Yamadori-type ventriculoscopes

Although cerebrospinal fluid (CSF) shunting is the most common neurosurgical treatment for hydrocephalus, the long-term results have still been unsatisfactory because of a wide variety of shunt complications. We have recently developed flexible ventriculoscopes (Yamadori-type) which have excellent image quality, maneuverability, and capabilities for endoscopic operation. Here we report the efficacy of the new treatment in 88 children with hydrocephalus who initially underwent either ventriculoscopic operation or shunting surgery. The primary outcome measures were the rate of shunt independency and/or shunt complications with a follow-up of 2 years in each group. We performed endoscopic third ventriculostomy in cases of aqueductal stenosis, cyst fenestration, and choroid plexus coagulation in limited cases of communicating hydrocephalus. Overall, thirty-three (75%) of the 44 children initially treated endoscopically did not require ventriculoperitoneal (VP) shunts. The endoscopic procedures were repeated in the remaining 11 children (25%) mostly less than 1-year-old who ultimately required endoscope-guided VP shunting. Even in such patients, there was virtually no need for shunt revisions and no major complications such as slit-like ventricle, meningitis, and intraventricular hemorrhage. These results were statistically highly significant (p < 0.0001) compared to a control group of 44 patients treated initially by VP shunting. Our data demonstrate that therapeutic ventriculoscopy is safe and clinically effective as the first-line treatment of hydrocephalus in children.

A patient whose cerebral aneurysm ruptured soon after an operation to remove a maxillary cyst

A hypertensive woman complained of a headache soon after an operation to remove a maxillary cyst. A computed tomogram showed evidence of subarachnoid haemorrhage and on angiogram an aneurysm of an anterior cerebral artery. The aneurysm was treated by clipping and the patient recovered.

Pineoblastoma showing unusual ventricular extension in a young adult--case report

A 19-year-old male presented with a 4-week history of headache. Neurological examination showed bilateral papilledema. Computed tomography revealed a pineal region mass with remarkable obstructive hydrocephalus. Magnetic resonance imaging showed a pineal region tumor continuously invading through the tectum into the cerebral aqueduct and the fourth ventricle with the preservation of the adjacent structures. The tumor appeared an iso- to hypointense mass on T1-weighted images, a heterogeneous iso- to hyperintense mass on T2-weighted images, and a heterogeneously enhanced mass after administration of contrast medium. Histological examination after endoscopic biopsy confirmed that the tumor was a pineoblastoma. Radiotherapy was given to the whole brain and the spinal cord, and magnetic resonance imaging showed complete remission of the tumor. Pineoblastomas are highly malignant tumors with seeding potential through the neighboring ventricle or along the meninges, and this type of tumor becomes larger with local extension. We found no previous reports of the continuous extension into the fourth ventricle. The present case showed ventricular extension with minimal mass effect to adjacent structures, and did not disturb ventricular configuration. According to the unusual finding of ventricular extension, this rare case of pineoblastoma requires adjuvant chemotherapy.

[A case of primary cerebral neuroblastoma surviving for eight years]

We report a case of a patient with primary cerebral neuroblastoma who has survived for 8 years. A 10-year-old boy was admitted to our hospital because of headache and nausea. CT scan on admission revealed a large cystic tumor on the right frontal lobe. Subtotal tumor resection was carried out. A second operation was performed for the residual tumors which were removed meticulously with confirmation of the absence of tumor cells on each frozen section. After tumor removal, YAG laser was applied at each local area. Histological diagnosis disclosed primary cerebral neuroblastoma. Because of postsurgical meningitis and parent's refusal, neither chemotherapy nor radiation therapy was performed. There have been no findings of the tumor recurrence during the last eight years, and now the patient is enjoying high school life to the full, without any neurological deficits. In reviewing the literature, outcomes of neuroblastoma cases are very poor. Our case seems to be one of the rare long-survival cases.

[A case of renal pelvic cancer with high serum level of CA 19-9]

A case of left renal pelvic cancer with a high level of serum CA19-9 is reported. Radiological examination showed a left renal pelvic cancer with lymph node metastasis, but did not reveal any tumors producing CA19-9 in any other organs. Chemotherapy was performed in addition to left total nephroureterectomy. The serum level of CA19-9 decreased to the normal range within three weeks after the operation. Immunohistochemical examination demonstrated that CA19-9 might have been produced from the tumor cells themselves in this case.

[Treatment and diagnosis of middle fossa arachnoid cyst: ventriculofiberscopy and cine-MRI]

The treatment of intracranial arachnoid cysts in controversial regarding its surgical indication and operative procedures. Conventional surgical approaches such as fenestration, membranectomy, and shunting operation are invasive. Also CT cisternography and/or RI cisternography are invasive, when it has been performed to evaluate the possible CSF communications between the arachnoid cyst and subarachnoid space. Between July 1994 and February 1997, 10 patients with intracranial middle fossa arachnoid cysts were treated with a newly developed ventriculofiberscope which is characterized by splendid mechanical flexibility and high resolution. The cine-MRI, which is a non-invasive diagnostic tool, is used to evaluate the CSF circulation around the cyst fenestration. The patients' ages ranged from 4 months to 10 years, with a mean of 4.46 years. The cyst locations were left middle fossa (9), and right (1). Eight patients presented with macrocrania, 4 with developmental delay, three with seizure, two with headache, and one with subdural hematoma. The patients were preoperatively evaluated by means of MRI and cine-MR images. In all patients ventriculofiberscopic procedures including cyst fenestration, membranous dissection, cyst puncture and shrivelling were successfully performed. Postoperative MR and cine-MR studies have shown reduction of the cyst size and appropriate CSF circulation. Neuroendoscopic procedures seem to be the choice for children with arachnoid cysts and the ventriculofiberscope proved to be very useful not only for cyst fenestration but also for cyst dissection. In addition, the non-invasive cine-MR studies are useful for long follow-up at OPD.

[14C-oxalate autoradiographic studies on distribution of oxalate and calcium oxalate crystal fixation in rat kidney]

To elucidate the intrarenal distribution of oxalate and to reveal the first site of calcium oxalate crystal fixation along the nephron, we carried out 14C-oxalate renal microautoradiography by the thaw mount method 30, 60 and 90 min after intravenous administration of 14C-oxalate, in normal rats and in hyperoxaluric rats fed a vitamin B6-deficient diet for 4 and 9 weeks. In normal rats, radioactivity was observed in the entire kidney area at 30 min after the injection and at 90 min there was radioactivity only in the papilla, where radioactivity appeared in the parenchyma, mamely the epithelial cells of collecting ducts and the surrounding interstitial tissue. In hyperoxaluric rats, microautoradiograms showed the spotted deposits of 14C-oxalate in both renal papilla and medulla. In 600 x magnification of the autoradiograms, most of the deposits were detected in the epithelial cells of collecting ducts and the surrounding interstitial tissue. These deposits were identified by a polarizing microscope and X-ray microanalysis as crystal deposits of calcium oxalate. These results indicated that oxalate remained for an extended period of time in the epithelial cells of collecting ducts and in the surrounding interstitial tissue in renal papilla, and the calcium oxalate crystals fixed to the same tissue was the first step in the development of calcium oxalate stones.

[The management of slit-like ventricle with the Medos programmable Hakim valve and the ventriculofiberscope]

A slit-like ventricle is one of the serious complications which can occur after a shunting operation. Low pressure valve systems are usually applied for hydrocephalus during infancy. As a result the shape of the ventricle often becomes slit-like after the operation. Many shunt dependent children with slit-like ventricles have to undergo shunt revisions repeatedly. From April 1995 to February 1997 the authors used the Medos programmable Hakim valve system for 20 hydrocephalic children with slit-like ventricles who had been suffering from multiple shunt problems. The patients ages at the operation were between 3-16 Male:Female was 12:8. Follow up periods were 10-20 months. In 12 of 20 patients the shunt revisions were performed at the time of shunt dysfunction and the valve pressure levels were able to be set at the highest levels without the appearance of any symptoms. In this group the size of all the ventricles had become slightly enlarged. In the other 8 patients the operations were performed for fear of other troubles arising if shunt revisions were neglected. In this group the valve pressure levels were set with reference to the intraoperative ICP. It took a relatively long period to elevate the valve levels. Shunt dysfunction due to obstruction of the ventricular catheter was seen in one case but the symptom was not so severe and the catheter which had firmly adhered to the choroid plexus was removed endoscopically. In 2 cases of this series the shunt systems were successfully eliminated. The authors report the method and efficacy of their series using the Medos programmable Hakim valve system and a newly developed ventriculofiberscope for the slit-like ventricle of children.

Role of the transition zone for elevating serum prostate-specific antigen in benign prostatic hyperplasia

BACKGROUND

Patients with benign prostatic hyperplasia (BPH) have a wide range of concentrations of PSA. However, it is not known what factors influence the concentration of serum PSA other than the prostate volume. BPH is composed of an enlarged transition zone (TZ) and other zones (nonTZ). The TZ is thought to play a more important role than the nonTZ in determining the concentration of serum PSA in BPH patients.

METHODS

We investigated the individual glandular zone volume, the amount of PSA produced by each zone and the PSA density in each zone in 23 patients with histologically-confirmed BPH. The PSA density in the TZ was calculated by dividing the difference between the serum PSA before and after surgical resection by the specimen weight. We examined the influence of these parameters on the concentration of serum PSA in BPH patients.

RESULTS

The serum PSA concentration correlated with the amount of PSA produced by the TZ (r=0.90, P< 0.0 1), but not the nonTZ (r=0.25, P=0.29). The concentration of serum PSA also showed a significant correlation with the TZ volume (r=0.67, P< 0.01) and the PSA density in the TZ (r=0.51, P< 0.05), but not with the PSA density in the nonTZ (r=-0.06, P=0.81). Also, age was inversely correlated with the PSA density in the TZ (r=-0.69, P< 0.01).

CONCLUSION

The hypertrophic prostate cell volume (TZ volume) and activity (PSA density in the TZ) significantly correlated with the concentration of serum PSA in BPH patients, and the TZ cell activity decreased inversely with age in these BPH patients.

Development of flexible ventriculoscope (Yamadori-type VII) and its application to experimental animals

We developed a new ventriculoscope (Yamadori-type VII), a 2.1 mm calibrated fiberscope with a monopolar coagulator, that can be inserted from the cisterna cerebellomedullaris into the third cerebral ventricle of experimental animals, like dogs. With the improved performance of the neuroendoscope compared to its prototype, Yamadori III, it was possible to inspect clearly and to produce electrocoagulative lesions accurately on any part of the intraventricular structures with minimal injury to nearby vital brain areas.

[Treatment of hydrocephalus without shunt placement: third ventriculostomy]

Hydrocephalus is usually treated by placing an extracranial CSF shunt. Endoscopic third ventriculostomy, however, has been revived recently as a less invasive method for treatment. We intended to avoid shunting or to eliminate the previously placed shunt with this procedure. The authors review their experiences on third ventriculostomy employing a flexible neuroendoscope under video monitoring in 14 cases of pediatric hydrocephalus. The result was that we succeeded in 11 cases (79%) by third ventriculostomy alone; we avoided shunting in 8 cases and eliminated a previously placed shunt in 3 cases. Clinical summary is shown on Table 1, and illustrative cases are presented with the figures and legend. The patients' group consisted of 8 males and 6 females. Their age ranged from 1 month to 17 years (average age, 6 yr) old. Background diseases of hydrocephalus were brain tumor in 6 cases, Chiari type I malformation in 3, intraventricular hemorrhage in 3, neonatal meningitis in 1 and arachnoid cyst in 1 case. In the remaining 3 cases, however, we failed to avoid the necessity of placing shunt because of indirect reasons (recurrence of tumor, infection after another operation, subdural fluid collection). There was no major complication in relation to third ventriculostomy, except for a moderate elevation of temperature of several days' duration following the procedure. Indication and outcome of this operation is also discussed. Endoscopic third ventriculostomy is an efficacious procedure for the treatment of hydrocephalus in selected patients.