Transcatheter retrieval of atrial septal defect and patent ductus arteriosus occluder: a guidance for device retrieval based on comprehensive bench tests

OBJECTIVES

The aim of this study is to establish a guidance for device retrieval based on comprehensive bench tests.

BACKGROUND

Device embolisation remains a major complication in transcatheter closure of atrial septal defect and patent ductus arteriosus. Although percutaneous retrieval is feasible in the majority of cases, surgical retrieval may be required in complicated circumstances. However, the methods of transcatheter device retrieval have not been completely established.

METHODS

Bench tests of device retrieval were performed to verify the appropriate retrieval method according to device type/size. The devices used for testing were Amplatzer Septal Occluder (Abbott, Chicago, IL, United States of America), Figulla Flex II (Occlutech GmbH, Jena, Germany), Amplatzer Duct Occluder-I (Abbott), Amplatzer Duct Occluder-II (Abbott), and Amplatzer Vascular Plug-II (Abbott). The retrieval equipment constituted diagnostic catheters (multipurpose catheter and right Judkins catheter, 4-Fr or 5-Fr, Gadelius Medical, Tokyo, Japan), delivery sheath and cables for each device, Amplatz goose neck snares (Medtronic, Minneapolis, MN, United States of America), OSYPKA CATCHER (Osypka ag, Rheinfelden-Herten, Germany), and OSYPKA LASSOS (Osypka). We investigated the retrieval equipment and sheath sizes required for a successful retrieval procedure for variously sized devices.

RESULTS

For patent ductus arteriosus devices, the type of snare and the snaring position are considered important. For atrial septal defect devices, simple snare capture or a double-snare technique with a sufficiently large sheath is effective. Special care should be taken when using the OSYPKA CATCHER for device retrieval.

CONCLUSIONS

The results of this study may assist in the selection of both capture devices and a retrieval sheath or a catheter for complete retrieval.

Usefulness of a Pulse Oximeter and Multimodality Imaging for Diagnosing Platypnea-orthodeoxia Syndrome

Platypnea-orthodeoxia syndrome (POS) is a rare disease characterized by dyspnea and hypoxemia in orthostatism that improves in the recumbent position. We herein report an 81-year-old woman with dyspnea in the upright position following thoracic vertebral compression fractures. After the patient's daughter brought a recording showing decreasing SpO₂ (peripheral capillary oxygen saturation) in the upright position as measured by a portable pulse oximeter outside the hospital, a small atrial septal defect (ASD) was detected. A contrast echocardiogram and four-dimensional flow magnetic resonance imaging demonstrated a right-to-left shunt. The patient's symptoms dramatically improved after percutaneous ASD closure. In conclusion, such new technologies are useful for diagnosing POS.

Risk Factors and Predictors of Cardiac Erosion Discovered from 12 Japanese Patients Who Developed Erosion After Atrial Septal Defect Closure Using Amplatzer Septal Occluder

Cardiac erosion is a rare serious complication following Amplatzer septal occluder (ASO) placement for atrial septal defect. Although multiple risk factors have been found, a useful predictor to prevent it has not been established yet. In 12 patients who developed erosion between 2005 and 2016 in Japan, we retrospectively observed patients' characteristics and transesophageal echocardiography findings immediately before and after ASO placement and at erosion onset. We compared risk factors of erosion, including absent aortic rim, device size/body weight ratio, device shape, or Valsalva sinus wall deformation pressed by either disk-edge, the maximum depth of which from the standard curve of the Valsalva wall was defined as Dent, between the 12 patients and 95 patients with Valsalva sinus wall deformation immediately after placement who did not develop erosion for 5 ± 3 years. Of the 12 patients, nine developed pericardial effusion with eight cardiac tamponade and three aorta-atrium fistula; all were surgically rescued. Surgical findings revealed that erosion in all patients occurred at the right and/or left atrial roof beside the Valsalva in the non-coronary cusp on which the disk-edge seemed to be pressing. The mean Dent immediately after the placement in patients with erosion was significantly deeper than without (2.48 ± 0.32 vs. 1.28 ± 0.38; p < 0.001). There were no differences in the other risk factors between the two groups. Dent is believed to be a useful indicator of erosion development after ASO placement. If Dent is > 2.0 mm, it is desirable to change the size or to replace the device.

Efficacy and Safety of Low-Dose Amiodarone Therapy for Tachyarrhythmia in Congenital Heart Disease

Amiodarone (AMD) is a class III anti-arrhythmic drug that is highly effective for tachyarrhythmia treatment. AMD is widely used in adults with congenital heart disease (CHD); however, higher doses of AMD (> 200 mg/day) can cause various non-cardiac side effects. The purpose of this study was to assess the efficacy, safety, and adverse events of low-dose AMD (≤ 200 mg/day) for tachyarrhythmia in patients with CHD. We retrospectively studied 80 patients with CHD and tachyarrhythmia who received oral low-dose AMD (≤ 200 mg/day) from January 2004 to March 2016. Low-dose AMD therapy was used to treat supraventricular tachycardia (SVT) in 51 patients and ventricular tachycardia (VT) in 29 patients. After a mean follow-up of 2.9 years for SVT and 3.2 years for VT, 36% and 65% of the patients with SVT and VT, respectively, were free from a first tachyarrhythmia recurrence for 3 years. The incidence of AMD-induced side effects was 23%, and all these cases consisted of thyroid dysfunction. Low-dose AMD was effective for the treatment of tachyarrhythmia in patients with CHD and had a relatively low incidence of side effects. These findings suggest that low-dose AMD is useful and effective for decreasing the frequency of tachyarrhythmia in patients with CHD and has a low incidence of side effects.

Current trends in stenting for aortic coarctation in Japan: Subanalysis of Japanese Society of Pediatric Interventional Cardiology (JPIC) stent survey

BACKGROUND

Stenting for aortic coarctation (CoA) has been accepted as an alternative to surgery for adolescents and adults, but only a few case have been reported in Japan. The purpose of this study was to provide a detailed review of Japanese national data on stenting of CoA.

METHODS

In a subanalysis of the data of the Japanese Society of Pediatric Interventional Cardiology (JPIC), we identified 35 patients with CoA who underwent stenting. We analyzed procedural characteristics including factors that may have contributed to hemodynamic effectiveness, and we compared these parameters between the patients under and over 15 years of age.

RESULTS

The mean ratio of balloon diameter/minimum lumen diameter (MLD) before stenting was 1.7 (range, 1.2-4.0), and the mean difference between the balloon diameter and the reference vessel diameter was -0.7 mm (range, -5.0 to +3.0 mm). %MLD/balloon diameter, which was defined as [(balloon diameter - MLD after dilation)/balloon diameter] × 100 predicted achievement of <10 mmHg pressure gradient after stenting. The sensitivity and the specificity of its cut-off of 7% were 93% and 47% (AUC, 0.7), respectively. There was no statistical difference between the two age groups under and over 15 years of age, in terms of selection criteria of stent size, balloon type used for deployment and immediate angiographic and hemodynamic result.

CONCLUSIONS

Stenting for CoA was clinically effective with few complications in Japan, even in patients not fully grown.

Ductal stenting using side-branch cell dilation for aortic coarctation in high-risk patients with hypoplastic left heart syndrome

For high-risk neonates with hypoplastic left heart syndrome (HLHS) undergoing Norwood operation, the strategy of bilateral pulmonary artery banding and ductal stenting is risky in case of coarctation of the aorta (CoA), often resulting in death. Therefore, we devised a new method of ductal stenting with side-branch cell dilation, which could overcome the constriction of the ductal arch with CoA in two HLHS patients. This is the first report that presents this method and the results. © 2015 Wiley Periodicals, Inc.

The importance of hybrid stage I palliation for neonates with critical aortic stenosis and reduced left ventricular function

The optimal management strategy for neonates with congenital aortic stenosis, two balanced ventricles, and duct-dependent systemic circulation (critical aortic stenosis) is still controversial. Thirteen patients with critical aortic stenosis underwent balloon aortic valvotomy (BAV) between 1996 and 2013, at the median age of 1 day old (range 0-28). Since 2010, bilateral pulmonary artery banding with ductal stenting following BAV was conducted for patients with reduced left ventricular (LV) function as a hybrid stage I palliation for the bridge to decision for further treatment. A follow-up was completed on all patients and the median follow-up period was 3.3 years (max 16.0). The overall survival rate at 15 years was 67.1 %. Six of the seven patients with maintained LV function could go on to the definitive Ross or Konno-aortic valve replacement at the median duration of 311 days after initial BAV, without any mortality. Three of four patients with reduced LV function died before 2010 with conventional treatment. With use of a hybrid stage I palliation, one of two patients ultimately underwent Fontan completion at 38 months of age and the other successfully underwent the definitive Ross-Konno operation at 9 months of age after recovery of the LV function. Although a statistically significant improvement has not been observed yet, the application of hybrid stage I palliation following BAV would be a favorable alternative for patients with reduced LV function to avoid a high-risk neonatal Ross or Norwood-type operation, and also to determine further treatment carefully.

Evaluation of Valsalva sinus wall deformation due to compression by the Amplatzer septal occluder and the potential for erosion development

OBJECTIVES

We studied whether the pressure exerted by the Amplatzer septal occluder (ASO) disk on the Valsalva sinus wall (VW) is a risk factor for erosion and attempted to determine the pressure that may trigger erosion.

BACKGROUND

The causes and mechanisms of erosion after ASO placement remain unclear.

METHODS

We reviewed 665 consecutive patients with atrial septal defects who underwent ASO closure at our hospital from 2005 to 2012. We used transesophageal echocardiography and other tests to evaluate disk-related VW deformation as a risk factor for erosion.

RESULTS

Immediately after ASO placement, intermittent VW deformation from either disk was determined in 54 of the 665 patients (8%). Of these 54 patients, only 1 exhibited late erosion (0.15%) during a follow-up of more than 4 years (0.035% a year). The maximum VW deformation depth relative to the standard curve, or dent, was 2.6 mm in this patient, whereas that in the remaining patients ranged from 0.5 to 2.0 mm. The dent values were significantly deeper in patients with contact between the left atrial disk and posterior atrial wall than in those without contact (P = 0.03). There was a significant negative correlation between dent and the aortic side-maximum device thickness (DT)/middle part-DT ratio (P = 0.04).

CONCLUSION

Although VW deformation, particularly deep VW deformation caused by pressure from either disk after ASO placement must be a recognized risk for erosion, which deformation level carries a stronger risk for erosion could not be concluded.

Management of ostium secundum atrial septal defect in the era of percutaneous trans-catheter device closure: 7-Year experience at a single institution

OBJECTIVES

This study aimed to review the single institutional experience of the repair of secundum atrial septal defect (ASD) after the initiation of percutaneous trans-catheter device closure, to confirm the current management strategy and outcomes.

METHODS

From August 2005 to December 2012, a total of 1026 (659 females, age 27±21 years) consecutive patients underwent the repair of ASD. Including eight patients who converted to surgical repair, 317 patients (31%) underwent surgical repair and 709 (69%) underwent trans-catheter device closure.

RESULTS

An embolized device into the left atrium was surgically retrieved in one patient soon after trans-catheter device closure without any postoperative complications. The other patient developed left atrium to aorta fistula due to late erosion, and required the removal of implanted device and patch closure of fistula and ASD 3 months after trans-catheter device closure. Whereas serious central nerve system complications occurred in three patients after the surgical repair including a 75-year-old patient with postoperative transient atrial fibrillation who subsequently developed aspiration pneumonia and died; there were no mortalities and no morbidities associated with cranial nerve function after trans-catheter device closure. A number of patients approached through partial sternotomy with limited skin incision have increased per year, and the length of skin incision was 5.1±1.2cm in pediatric patients weighing less than 15kg (n=40), 6.9±1.9cm in the remaining pediatric patients (n=91), and 10.0±2.5cm in young adult females (n=10).

CONCLUSION

Percutaneous trans-catheter ASD closure was safely performed under the support of a surgical team. The cosmetic outcome of surgical closure is improving after initiation of partial sternotomy via limited skin incision for the pediatric population and young adult females. Prior to the treatment, the physicians must thoroughly inform patients and families of the advantages and disadvantages of both treatment options.

Haemodynamic characteristics before and after the onset of protein losing enteropathy in patients after the Fontan operation

OBJECTIVES

Determinant risk factors for developing protein losing enteropathy (PLE), including haemodynamics, remain unclear in patients after the Fontan operation.

METHODS

Our purpose was to characterize the serial PLE haemodynamics before and after the onset and to determine the risk factors based on the cardiac catheterization-based analysis.

RESULTS

Of 354 Fontan survivors who had undergone postoperative cardiac catheterizations, we experienced 26 PLE patients during the follow-up. Non-left ventricular morphology systemic ventricle, functional one-lung pulmonary circulation and an early postoperative high central venous pressure (CVP) were associated with the PLE onset and the high CVP (odds ratio (OR) = 1.19 per 1 mmHg, 95% confidence interval (CI) 1.04-1.37, especially ≥12 mmHg, OR = 3.09, 95% CI 1.25-7.64, P < 0.05 for both) and one-lung pulmonary circulation (OR = 10.0-10.5, P < 0.001) independently predicted the onset. At the time of the PLE onset, a Fontan route stenosis/obstruction, arrhythmias, ventricular dysfunction/heart failure and pulmonary arterio-venous fistulae were demonstrated in 10 (38%), 8 (31%), 4 (15%) and 3 (12%) patients, respectively. When compared with 56 excellent Fontan survivors, the high CVP, ventricular end-diastolic pressure, and pulmonary artery resistance, and the low arterial oxygen saturation, systemic artery pressure, and ventricular ejection fraction characterized the pre-PLE Fontan haemodynamics (P < 0.05-0.0001). However, the following intensive treatments reduced the CVP, systemic artery pressure and cardiac output (P < 0.05-0.01), resulting in haemodynamics no different from those of the excellent survivors, except for the low systemic pressure (P < 0.0001).

CONCLUSIONS

The pre-PLE haemodynamics was characterized by several impaired haemodynamics, while those after PLE only by a low systemic pressure. A high early postoperative CVP was the only haemodynamic predictor for a new onset of PLE. Strict selective criteria for the operation and strategies to eliminate CVP-raising factors are mandatory to prevent a new onset of PLE.

Impact of the evolution of the Fontan operation on early and late mortality: a single-center experience of 405 patients over 3 decades

BACKGROUND

Postoperative mortality has decreased in patients undergoing the Fontan operation, and the determinants of such mortality may also have changed significantly.

METHODS

We conducted a study intended to focus on clarifying the determinants of mortality in 405 consecutive patients who had undergone a Fontan operation (62 patients after an atriopulmonary connection, 105 after an intra-atrial rerouting, and 238 patients after an extracardiac rerouting) between 1979 and 2010.

RESULTS

The overall 1-year, 5-year, 10-year, and 15-year rates of survival were 87.1%, 84.6%, 83.4%, and 81.6%, respectively, and the type of procedure as well as heterotaxy syndrome, ventricular ejection fraction, and atrioventricular valve repair at the time of the Fontan operation were independent predictors of overall mortality (p < 0.05 for all). Heterotaxy syndrome and atrioventricular (AV) valve repair were independent predictors of early (less than 6 months postoperative) mortality and the type of procedure was an independent predictor of late (6 or more months postoperative) mortality (p < 0.05 to 0.01). In the era of intra-atrial rerouting, heterotaxy syndrome was the only independent predictor of total, early, and late mortality (p < 0.05 for all), whereas a low ejection fraction, AV valve repair, and repair of a total anomalous pulmonary vein connection, rather than heterotaxy syndrome, were independent predictors of total or early mortality or both (p < 0.05 for all) in the era of extracardiac rerouting.

CONCLUSIONS

Even in the modern era of extracardiac rerouting in the Fontan operation, a low ventricular ejection fraction, AV valve dysfunction, or a total anomalous pulmonary vein connection remain significant risk factors for mortality in patients with a single-ventricle physiology.

Long-term outcome of coil occlusion in patients with patent ductus arteriosus

BACKGROUND

Coil occlusion has been widely indicated for the closure of patent ductus arteriosus (PDA). Although many reports have shown the efficacy and safety of coil occlusion, the long-term outcome in patients remains controversial. Here, we analyzed the long-term outcome of coil occlusion in patients with PDA in Japan.

METHODS AND RESULTS

We collected the longitudinal data of patients who underwent coil occlusion between 1995 and 2009. A total of 310 coil occlusions were performed in 298 patients with PDA. The median minimum duct diameter was 1.4mm. Successful coil occlusion was achieved in 286 patients (96.0%), and total adverse events were seen in only 28 cases (9.0%). The median follow-up period was 50 months. The occlusion rates at 1 month, 6 months, 1 year, 2 years and 5 years were 90.1%, 94.4%, 97.4%, 97.8% and 97.8%, respectively. Patients with a large PDA (≥4mm) showed a higher rate of residual leakage than those with a small (<2mm) or moderate (2-4mm) PDA (P=0.004). Patients who underwent this procedure in the early study period also showed a higher rate of residual leakage than those in the late study period.

CONCLUSIONS

Coil occlusion is an effective procedure for patients with PDA. Our data indicate that the long-term outcome is promising without any adverse events.

Ataxic vs painful form of paraneoplastic neuropathy

OBJECTIVE

To characterize the clinicopathologic features of ataxic and painful forms of paraneoplastic neuropathy.

METHODS

Clinical, electrophysiologic, and histopathologic findings were assessed in 17 patients with paraneoplastic neuropathy.

RESULTS

Clinical features can be categorized into two groups: one group (13 patients) with predominantly deep sensory disturbance and a second group (4 patients) with predominantly superficial sensory disturbance. The former group showed severe sensory ataxia and predominantly large myelinated fiber loss in the sural nerve. The latter group showed marked pain, in particular, severe mechanical hyperalgesia, and predominantly small myelinated and unmyelinated fiber loss. Nerve conduction assessment indicated an axonal neuropathy pattern in both groups, while sensory action potentials were more markedly diminished in the sensory ataxic form. Anti-Hu antibodies were detected in half of the patients in both groups. Treatment for cancer was effective to improve or stabilize neuropathic symptoms in some cases from both groups. Immunotherapy was effective only for a short time.

CONCLUSIONS

Paraneoplastic neuropathy can be characterized into two groups by the presence of sensory ataxia or severe spontaneous pain and severe mechanical hyperalgesia. Preferential small myelinated and unmyelinated fiber loss correlated to the cases of severe pain.

Feasibility and clinical impact of transcatheter closure of interatrial communications after a fenestrated Fontan procedure: Medium-term outcomes

OBJECTIVE

This study was to review an institutional experience with transcatheter closure of Fontan fenestrations and its impact on clinical care.

BACKGROUND

An interatrial fenestration improves postoperative outcomes in high-risk children undergoing a Fontan repair. While technical feasibility has been well defined, the clinical impact of subsequent closure is not well defined.

METHODS

Transcatheter closure of a surgically created or additional interatrial communication was attempted in 152 children at a median interval of 13.8 months after surgery. The clinical records were reviewed for demographic and anatomical characteristics, previous surgeries; catheterization data, and status at latest follow-up.

RESULTS

Mean oxygen saturation and right atrial pressure increased acutely from 87% +/- 5% to 96% +/- 3% (P < 0.001) and 12 +/- 2 mm Hg to 13 +/- 3 mm Hg (P < 0.001), respectively. Higher systemic venous atrial pressures after occlusion correlated with higher pulmonary artery pressures (P = 0.05) before the Fontan procedure and with higher right (P < 0.001) and left atrial (P = 0.001) and ventricular end-diastolic pressures (P < 0.001) immediately before occlusion. Complications included device malposition in 2 children, 1 child each had an air embolism and post-procedural bleeding, and each self-limiting and 1 child had acute ST elevation in inferior ECG leads because of occlusion of the acute marginal branch which was treated with angioplasty and placement of a stent. At follow-up (median 4.5 years), the mean oxygen saturation was 95% +/- 3%. Residual interatrial leaks were noted echocardiographically in 9%. Two children developed protein-losing enteropathy after fenestration closure. No deaths or strokes were observed in follow-up.

CONCLUSIONS

Transcatheter occlusion of Fontan fenestrations is safe with acute and persistent improvements in oxygen saturations.

Coil Occlusion of Patent Ductus Arteriosus Impact of 0.052-Inch Gianturco Coil Without Amplatzer Duct Occluder

BACKGROUND

Coils are the only devices available for transcatheter occlusion of patent ductus arteriosus (PDA) in Japan. Since April 1999, we have introduced a 0.052-inch Gianturco coil (0.052-inch coil) to close PDA >or=2.5 mm.

METHODS AND RESULTS

A retrospective survey of the outcome of coil occlusions for PDA >or=2.5 mm before and after the 0.052-inch coil became available found that (1) the frequency of PDA >or=2.5 mm among all candidates for coil occlusion significantly increased after the availability of a 0.052-inch coil (p<0.01); (2) deployment complicated by migration (p<0.01), and prolonged procedure time (p<0.05) were significantly decreased after the introduction of the 0.052-inch coil. In a multivariate logistic regression model for uneventful deployment adjusted for age, pulmonary to systemic flow ratio, and use of a 0.052-inch coil, use of the 0.052-inch coil significantly decreased eventful deployment (p<0.05); and (3) successful deployment of a coil for PDA >or=4 mm significantly increased with the 0.052-inch coil (p<0.01). Complete occlusion was achieved once deployment was successful.

CONCLUSION

Introduction of the 0.052-inch coil decreased complicated coil occlusion deployment for PDA >or=2.5 mm, and contributed to a better likelihood of coil occlusion for PDA >or=4 mm.

Changes in causes of sudden deaths by decade in patients with coronary arterial lesions due to Kawasaki disease

Over a 25-year period, we encountered 12 patients who died suddenly with coronary arterial lesions due to Kawasaki disease. We report their clinical course, and analyze the happenings of their deaths. Of the 12 patients, 10 were dead on arrival at hospital. Their age at death ranged from 13 months to 27 years, with a median of 16 years, and the interval from the onset of Kawasaki disease to death ranged from 2 months to 24 years. In 4 patients, death was found to be due to myocardial infarction, while in the remaining 8, it could not be determined. In 7 patients, coronary angiograms obtained less than 4 months after the acute onset of Kawasaki disease showed lesions bilaterally, most being giant aneurysms. Myocardial infarction had occurred in 6 patients prior to their death. In 1 patient of the late 1970s, who collapsed after running, cardiac sequels had not been suspected prior to autopsy. During the 1980s, 3 infants with bilateral giant aneurysms died within a year of the initial onset of Kawasaki disease, with acute myocardial infarction being the cause in 2 of them. In the late 1990s, and the 2000s, 5 patients died suddenly with left ventricular dysfunction, their ejection fractions being less than 40 percent more than 20 years after the initial onset of Kawasaki disease. Prior to their sudden deaths, they had had no cardiac events for many years, but had suffered previous myocardial infarctions. Multifocal premature ventricular contractions, and non-sustained ventricular tachycardia, are probable risk factors in such patients. Careful follow-up, checking for ventricular arrhythmia, is needed to prevent sudden death in patients suffering left ventricular dysfunction in the setting of Kawasaki disease.

Late distortion of the original Palmaz stent implanted in postoperative lesions associated with congenital heart disease

The objective of this study was to report late distortion of a Palmaz stent. Late distortion of an original Palmaz stent, implanted in an extracardiac lesion, is rare. We completed a 1-year follow-up of 54 patients who had been implanted with 80 Palmaz stents in extracardiac lesions. Distortion of two stents was detected in two patients. For case 1, we implanted a P188 stent for supravalvar pulmonary stenosis complicating an arterial switch operation in a 14-year-old girl. Seven months later, we found compression of the stent. Although we implanted two P308 stents anterior to the distorted stent, distortion of both stents developed after 1 month. Two more P308 stents placed inside each stent were gradually recompressed. A CAT scan showed compression of the stent by a dilated sinus of valsalva. For case 2, we implanted a P308 stent for stenosis of the superior vena cava after Williams operation in an 11-year-old boy. A chest X-ray documented longitudinal compression of the stent 27 months after implantation and a CAT scan showed the ascending aorta was in contact with the stent. A Palmaz stent may be distorted when implanted in a lesion adjacent to a pulsating aorta.

Production of large multienzyme complex by aerobic thermophilic fungus Chaetomium sp. nov. MS-017 grown on palm oil mill fibre

AIMS

A novel xylanolytic multienzyme complex of the aerobic thermophilic fungus Chaetomium sp. nov. MS-017 was produced on palm oil mill fibre (POMF) and partially characterized.

METHODS AND RESULTS

The assay of the extracellular enzymes of Chaetomium sp. nov. MS-017 on POMF in solid-state fermentation revealed cellulolytic, pectinolytic and extremely high xylanolytic activities. The protein was purified by Sephadex G-200 column chromatography. The SDS-PAGE demonstrated that the purified protein is a complex with at least five xylanolytic, four cellulolytic and eight pectinolytic components. The characterization of the complex at various temperatures showed that the reactivity and stability of the complex are not lost up to 60 degrees C. In addition, the complex was very stable in a wide range of pH (3-9) and at high concentrations (10 mm) of cations and EDTA. The major products of xylan hydrolysis by the purified complex were determined to be xylobiose and xylotriose by thin-layer chromatography.

CONCLUSION

Chaetomium sp. nov. MS-017 preferentially produces a xylanolytic multienzyme complex on POMF in solid-state fermentation.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report on the xylanolytic multienzyme complex produced by an aerobic thermophilic fungus.

Acute recoil of stents used for the relief of stenotic great vessels in the setting of congenital cardiac disease

We implanted either large or medium Palmaz stents, or a Palmaz Corinthian stent, in various stenotic vessels, such as the pulmonary arteries, pulmonary veins, aorta, or superior caval vein. Using angiograms, we measured the diameter of the stenotic vessel before or after the implantation, the minimal diameter of the lumen, the minimal diameter of the largest fully expanded balloon used to expand the stent, and the diameter immediately after withdrawal of the balloon. The minimal diameter of the fully expanded balloon, and the minimal diameter of the lumen subsequent to expansion, were 8.2 +/- 2.4, and 7.7 +/- 2.3 mm, giving an absolute recoil of 0.5 +/- 0.4 mm, and a proportional recoil of 7 +/- 4%. There was no significant difference in either the absolute or proportional recoil for any of the stents, or for any of the different stenotic vessels. The proportional recoil correlated linearly with the minimal diameter of the lumen prior to the procedure, and with the ratio of the stenosis to the balloon, while the diameter of the stenotic vessels, the minimal diameter of the largest fully expanded balloon, the proportional stenosis prior to the procedure, and the ratio of the balloon to the diameter of the stenotic vessel, had no significant correlation with proportional recoil. The proportional recoil exceeded more than one-tenth when the minimal diameter of the lumen prior to the dilation was less than 3 mm, or the ratio of the balloon to the stenosis was greater than 3.0. An absolute recoil of around 1 mm is common when a large or medium Palmaz, or a Palmaz Corinthian stent, is implanted in great vessels. Balloons with a diameter of approximately one-tenth greater than that of the adjacent vessel may be needed if the minimal diameter of the lumen is small prior to the procedure.

Balloon angioplasty of postoperative coarctation in the transverse arch in infants: protecting the common carotid artery

We performed balloon angioplasty in three patients with postoperative coarctation in the transverse arch adjacent to the left common carotid artery. The age at arch reconstruction was 5, 6, and 2 days, while the interval between operation and balloon dilatation was 59 days, 87 days, and 12 months, respectively. Two balloons, one in the stenosis and the other in the left common carotid artery, were introduced over a wire sequentially and inflated simultaneously until the waist of the balloon in the arch disappeared. After balloon dilatation, a significant reduction in the peak-to-peak pressure gradient and an increase in vessel diameters were observed in all patients. Further growth of the transverse arch was documented at follow-up in two patients. No aneurysm has been detected in any patients. We believe that placing a protective balloon in the neck vessel increases safety during balloon dilatation of coarctation in the transverse arch.

Stent implantation and subsequent dilatation for pulmonary vein stenosis in pediatric patients: maximizing effectiveness

The outcome of stent implantation and redilatation was investigated in 4 pediatric patients with 7 stenotic lesions of the pulmonary vein (PV), paying particular attention to late neointimal proliferation. The minimal diameter of the lesions increased from 0.8-3.6 (2.3+/-1.1) mm to 3.6-8.4 (5.1+/-1.6) mm immediately after stent implantation. Although the pressure gradient across the lesion was not measured in patient 4, in patients 1-3, it decreased from 4-34 (18+/-13) mmHg to 3-15 (7+/-4) mmHg. Except for case 4, who achieved a lesion diameter of 8.4 mm after initial stent dilatation, the other 6 lesions all restenosed within a few months, with an increasing pressure gradient. One patient with multiple PV stenoses associated with persistent severe pulmonary hypertension died suddenly. However, repeat dilatations were effective in all other lesions. Furthermore, in one lesion in patient 1, no serious restenosis developed for 20 months after the lesion was dilated up to 5.6 mm. Although further follow-up is mandatory, the final stent diameter within a vessel may determine long-term patency, and aggressive redilatation may be crucial for successful therapy of such a difficult disease.

Isolation of a novel thermophilic fungus Chaetomium sp. nov. MS-017 and description of its palm-oil mill fiber-decomposing properties

Palm-oil mill fiber (POMF) is a fibrous, natural hard material discharged in enormous amounts from palm-oil mills in tropical plantations; therefore, research to find microorganisms that decompose POMF was conducted. As the result of screening, a new thermophilic fungus, Chaetomium sp. nov. MS-017, exhibiting rapid growth on POMF was isolated from rotted wood. Based on partial characterization of the decomposition of POMF, it was shown that MS-017 preferentially assimilates polysaccharides, especially hemicelluloses such as xylan. A preliminary composting study indicated that MS-017 produced 855 g of decomposed product from 1,000 g of intact POMF in 12 days under optimized solid-culture conditions. The decomposition rate of POMF was 23% (w/w), and the cell yield calculated from consumed POMF was as high as 36% (w/w). These results indicate that MS-017 has a very high potential to decompose POMF and that it is suitable for economical production of compost to recycle by-product biomass from oil-palm plantations.

Potential goals for the dimensions of the pulmonary arteries and aorta with stenting after the Fontan operation

The purpose of this study was to clarify desired stent sizes for stenotic lesions in the post-Fontan circulation. Using angiograms from 22 patients before and at late follow-up (> or = 15 years) after the Fontan operation, we measured the maximum diameters of the proximal pulmonary arteries (PA) and the descending aorta. The diameters of the PA ipsilateral to the inferior vena cava, contralateral to the inferior vena cava, and descending aorta after the Fontan were 10.6-22.6 (15.8 +/- 3.3), 8.0-19.1 (12.9 +/- 3.1), and 12.1-18.9 (15.8 +/- 2.0) mm, respectively, while the percent of normal predicted diameters (% N) were 55%-104% (70% +/- 14%), 38%-99% (66% +/- 17%), and 46%-74% (60% +/- 7%), respectively. Despite somatic growth, the % N of all vessel diameters decreased significantly after the Fontan operation. In conclusion, smaller-sized stents should be acceptable for both the pulmonary artery and descending aorta in the Fontan circulation.

Late neointimal proliferation following implantation of stents for relief of pulmonary arterial stenosis

On the assumption that the diameter of the reference vessel might determine the thickness of neointimal coverage of stents placed in the pulmonary arteries, we analyzed the angiograms of 28 lesions in 17 patients who underwent follow-up cardiac catheterization. Excluding 2 lesions where late stenosis was determined mainly by recoil of greater than 30%, we investigated the neointimal thickness of 26 lesions in 16 patients. Several factors that might contribute to late re-stenosis were also analyzed. Age and body weight at implantation ranged from 0.8 to 20 years, with a median of 6 years, and from 6.8 to 77.5 kg, with a median of 17.6 kg. Follow-up interval was from 6 to 15 months, with a median of 6 months. There was a significant increase in diameter, as well as a reduction in pressure gradient, immediately after the implantation of stents. Although there was no significant difference between the achieved diameter and the diameter of the stent at follow-up, the diameter of the lesion at follow-up was significantly smaller than the diameter achieved by stenting. The increase in the pressure gradient at follow-up was slightly greater in 4 lesions where the late reduction in diameter was greater than 30% than in the 18 lesions where this was less than 30% (p = 0.05). The diameter of the reference vessel, and the diameter by stenting correlated with the late reduction in diameter. All lesions with diameter reduced greater than 30% had a reference diameter of less than 6.1 mm, and a diameter achieved by stenting of less than 6.5 mm. Late loss in luminal diameter directly correlated with the thickness of the neointimal coverage. In conclusion, close observation should be mandatory following implantation of stents in small pulmonary arteries.

Effects of thyroid hormone deficiency on electrocardiogram findings of congenitally hypothyroid neonates

Hypothyroid status is believed to cause various metabolic changes in infants. However, it is interesting that even severely hypothyroid neonates, detected during mass neonatal screening, rarely show bradycardia, hypothermia, or inactivity. To study cardiac functions of screen-detected neonates with congenital hypothyroidism (CH), we recorded the electrocardiograms (ECG) of 53 screen-detected CH neonates before levothyroxine (LT4) replacement therapy, and 15 age-matched normal neonates for controls. The 53 CH neonates were divided into two groups according to initial serum thyroid hormone levels: a mildly hypothyroid group (n = 37), serum thyroid-stimulating hormone (TSH) less than 100 microIU/mL and free thyroxine (FT4) 0.6 ng/dl or more; and a severely hypothyroid group (n = 16), TSH 100 microIU/mL or more and FT4 less than 0.6 ng/dL. TSH, FT4, and other blood chemicals were measured on an autoanalyzer (Hitachi 7170). After blood sampling, the ECG was recorded during induced sleep by oral administration of triclofos sodium syrup. ECG parameters, including HR, PR, QRS, QT time and corrected QT time (QTc) were automatically obtained, using an auto-ECG analyzing system. The following results were obtained. No CH patients showed abnormal ECG findings. There was no significant difference of the mean heart rates (HRs) between the mildly hypothyroid (147.5 +/- 16.3 beats per minute) and the control group (148.3 +/- 12.1 beats per minute). The mean HR in the severely hypothyroid group (134.0 +/- 17.9 beats per minute, p = 0.007) was significantly low compared with the normal control group. However, all values were within normal ranges. QTc in the severely hypothyroid group (0.414 +/- 0.015, p = 0.033) was significantly shorter than in the control group (0.440 +/- 0.052). No statistical differences of PR, QRS, and QT time were noted among the three groups. All ECG parameters were within normal ranges. HR positively correlated with FT4 and log (FT4), and negatively with TSH and log (TSH). From these results we conclude that the deficiency of thyroid hormones does not affect ECG findings of congenitally hypothyroid neonates. This may be consistent with the unexpectedly mild signs and symptoms of screen-detected hypothyroid neonates.

Infant case with a malignant form of Brugada syndrome

We report a 6-month-old Japanese infant with a malignant form of Brugada syndrome, who had frequent episodes of ventricular fibrillation (VF) and nonsustained polymorphic ventricular tachycardia (VT). To the best of our knowledge, this infant is the youngest patient reported to have Brugada syndrome. Continuous infusion of a beta-adrenergic agonist and intravenous injection of a parasympathetic antagonist suppressed the electrical storm of polymorphic VT and VF. Combined oral administration of a beta1-adrenergic agonist, a parasympathetic antagonist, and quinidine has successfully suppressed recurrences of VT or VF for 6 months, and the combination may have the potential to decrease the incidence of VT or VF as an adjunctive therapy with prophylactic placement of an implantable cardioverter defibrillator.

Dialysis-related spinal canal stenosis: a clinicopathological study on amyloid deposition and its AGE modification

Three cases operated for spinal canal stenosis induced by dialysis-related amyloidosis (DRA) were investigated clinicopathologically. Cases were all-male, and had undergone hemodialysis around 20 years. In two cases, cervical plain X-rays showed only minor spondylotic changes. However, magnetic resonance imaging (MRI), myelography, and computed tomography (CT) showed extradural thickness with compression on the cervical spinal cord and cauda equina. In one case cervical X-rays showed typical destructive spondyloarthropathy (DSA), and MRI showed compression myelopathy. Surgical treatment on both cervical and lumbar spine in two cases and on cervical spine only in one case successfully reduced the symptoms. Extradural thickened tissue and ligament flavum obtained during surgery were studied histopathologically and immunostained by using anti-CD68, anti-beta2-microglobulin (beta2m), and anti-advanced glycation end product (AGE) antibody. Congo red stain showed diffuse or nodular amyloid deposition, and immunostaining with anti-beta2m and anti-AGE antibodies also demonstrated the same distribution pattern. Thus, beta2m-positive amyloid tissue in the extradural thickness (extradural amyloid deposition) was immunohistochemically demonstrated to be modified with AGE. Inflammatory reaction with histiocytic and giant cell infiltration was also shown around the amyloid tissues. There were CD68-positive cells, and some cells were positive for AGE and beta2m. These findings suggest that beta2m accumulation and inflammatory reaction finally promote destruction of connective tissues. MRI, CT and/or myelography are necessary for diagnosing spinal canal stenosis accompanied by DRA. In conclusion, we propose a more comprehensive concept of dialysis-related spinal canal stenosis, which includes both DSA and myeloradiculopathy induced by extradural thickness.

Influence of emission from rice straw burning on bronchial asthma in children

BACKGROUND

Emission from rice straw burning (ERSB) is observed everywhere after harvest of rice in Niigata Prefecture every year. Pediatricians and many guardians in this district have had the impression that ERSB may induce asthma attack. Recent studies have suggested that particulate air pollution plays a role in the exacerbation of asthma. The authors investigated relationship of ERSB to asthma attack in children.

METHODS

A questionnaire on rice straw burning (RSB) was circulated to guardians and pediatric institutions. Change in the monthly number of children with asthma attack (CAA) for 5 years from January 1994 to December 1998 was investigated. In addition, change in the number of CAA from the meteorologic conditions and RSB was investigated from the fourth week of August to the third week of September in 1996, 1997 and 1998. Challenge test exposure to ERSB was tried on a volunteer adult with chronic asthma. The situation of air pollution was examined by measuring suspended particulate matter (PM10). The relationship between PM10 and the number of CAA was studied.

RESULTS

A majority of the guardians had the impression that ERSB induces asthma attack. Pediatricians replied similarly to the questionnaire. The number of CAA visiting our emergency room and admitted to our ward increased in the season of RSB. The PM10 had a significant correlation with the number of CAA. It was suggested that the increase in CAA may be not due to the meteorologic conditions, but to the influence of ERSB.

CONCLUSION

The ERSB has made an issue of air pollution. Furthermore, the possibility that ERSB induces or exacerbates asthma attack has become clear in the present study. Therefore, it is recommended that RSB should be abolished for the health of inhabitants, especially children with asthma.

Sympathetic skin response in diabetic children: do diabetic children have diabetic neuropathy?

BACKGROUND

Abnormal sympathetic skin response (SSR) has been reported in adult patients with diabetic neuropathy. In addition, other studies have revealed abnormal SSR in diabetic patients not having autonomic symptoms and autonomic dysfunctions. These findings have been only obtained from adult patients. There have been few reports on the autonomic functions in diabetic children. Accordingly, it is not clear whether the autonomic neuropathy occurs in diabetic children. The aim of the present study is to clear autonomic function in children with insulin-dependent diabetes mellitus by SSR.

METHODS

The SSR was measured in 28 normal healthy children and in eight patients with IDDM not having symptoms of dysautonomia. The SSR was elicited using 10 stimuli on programmed Nihonkoden Neuropack Sigma model machine. Following a single electrical stimulation, four SSR were recorded in both the palms and the soles simultaneously.

RESULTS

The SSR were simultaneously obtained in 100% of the two groups. The amplitudes in the palms and soles were not significantly different between the two groups. The mean and shortest latency in the soles were significantly longer in the IDDM group than in the control group (P < 0.01). None of the measurements of SSR revealed correlation with duration of diabetes and onset of illness.

CONCLUSIONS

Diabetic neuropathy may not have occurred in young patients having shorter duration of illness. Conversely, assuming that prolonged latency is abnormal, it may even have occurred in them. Follow up on these patients with prolonged latencies would be required.