Childhood suffering: hyper endemic echinococcosis in Qinghai-Tibetan primary school students, China.

BACKGROUND: As part of an ongoing program that aims to use early detection and timely treatment to improve the control of echinococcosis, especially in younger age groups, we undertook a series of active surveys among Qinghai-Tibetan children in the Qinghai Province of Northwestern China in 2011 and 2012. The significant outcomes that resulted from this study emphasize the need to draw attention to echinococcosis, both alveolar echinococcosis (AE) and cystic echinococcosis (CE), so that policy development is promoted and suitable avenues for control are identified in the highly endemic areas on the Tibetan Plateau. METHODS: A total of 19 629 primary school students, aged 6-18 years, with a dominant Tibetan background underwent abdominal ultrasound examination, and 86.4% of the compliant students donated 2-5 ml of venous blood for serological tests. All the abnormal ultrasound results were recorded. If identified as echinococcosis, the disease lesion was assessed according to the WHO-Informal Working Group on Echinococcosis (WHO-IWGE) classification for AE and CE. Among the surveyed students, the prevalence by school was compared among geo-locations, sex and age groups. The clinical image presentations were analyzed according to lesion number, size, the location in the liver and the classification stage. Statistical significance was set at P-value < 0.05 for comparisons among groups. RESULTS: A total of 341 students (1.7%) were identified by ultrasound as having either CE (119, 0.6%) or AE (222, 1.1%). The highest prevalence rates of childhood AE cases occurred in the Tehetu (12.1%) and Moba (11.8%) townships in Dari County. There was a high seropositive rate (37.0%) and a heterogeneous distribution of cases, with a prevalence ranged from 0 to 12.1% for AE and 0-2.9% for CE. Moreover, the seropositive rate ranged from 0.7-45.1% across different schools. CONCLUSIONS: The high prevalence of echinococcosis in Qinghai-Tibetan primary school students reflects a lack of knowledge about Echinococcus spp. transmission. The combination of systematic education for children and regularly performed anthelmintic treatment for dogs could achieve the goal of sustainable hydatidosis control.

Lasiopodomys fuscus as an important intermediate host for Echinococcus multilocularis: isolation and phylogenetic identification of the parasite.

BACKGROUND: Echinococcus multilocularis causes alveolar echinococcosis (AE) and is widely prevalent in Qinghai Province, China, where a number of different species have been identified as hosts. However, limited information is available on the Qinghai vole (Lasiopodomys fuscus), which is hyper endemic to Qinghai Province and may represent a potential intermediate host of E. multilocularis. Thus, L. fuscus could contribute to the endemicity of AE in the area. METHODS: Fifty Qinghai voles were captured from Jigzhi County in Qinghai Province for the clinical identification of E. multilocularis infection via anatomical examination. Hydatid fluid was collected from vesicles of the livers in suspected voles and subjected to a microscopic examination and PCR assay based on the barcoding gene of cox 1. PCR-amplified segments were sequenced for a phylogenetic analysis. E. multilocularis-infected Qinghai voles were morphologically identified and subjected to a phylogenetic analysis to confirm their identities. RESULTS: Seventeen of the 50 Qinghai voles had E. multilocularis-infection-like vesicles in their livers. Eleven out of the 17 Qinghai voles presented E. multilocularis infection, which was detected by PCR and sequencing. The phylogenetic analysis showed that all 11 positive samples belonged to the E. multilocularis Asian genotype. A morphological identification and phylogenetic analysis of the E. multilocularis-infected Qinghai voles confirmed that all captured animals were L. fuscus. CONCLUSIONS: L. fuscus can be infected with E. multilocularis and plays a potential role in the life cycle and epidemiology of E. multilocularis in the Qinghai-Tibetan Plateau of China.

[An Epidemiological Survey on Echinococcosis in Yushu Prefecture of Qinghai Province].

Objective: To investigate the prevalence of echinococcosis in Yushu Prefecture of Qinghai Province in 2012. Methods: Two to three towns were selected in each of Chengduo, Nangqian, Qu malai, Yushu, Zaduo and Zhiduo Counties from June to August in 2012. Ultrasound examination was conducted for residents aged over 1 year, and ELISA was performed to detect serum antibody against Echinococcus. Visceral dissection was performed to detect hydatid infection in rodents and livestock. ELISA was used to detect Echinococcus antigen in collected dog feces. Results: A total of 7 025 residents received ultrasound examination, of whom 319 showed hydatid cysts with a morbidity rate of 4.54%. ELISA showed a serum antibody positive rate of 16.38% （457/2 790）. The mobidity of hydatid disease was highest in Chengduo County （7.41%, 181/2 444）, and the rate of serum antibody was highest in Yushu County （23.18%, 127/548）. The morbidity and serum antibody in males were 3.91% （118/3 018） and 13.93% （172/1 235） respectively, and those in females were 5.02% （201/4 007） and 18.33% （285/1 555）. In terms of age distribution, the morbidity was relatively higher in residents of 60- （8.39%, 38/453） and 40- years （6.61%, 67/1 014）; and the rate of serum antibody was highest in residents over 70 years （33.93%, 19/56）. In terms of occupation, the morbidity was relatively higher in herdsmen （5.28%, 252/4 777）, Herdsmen-peasants （6.52%, 24/368）, and religious workers（3.37%, 11/326）, while the rate of serum antibody was relatively higher in children（24%, 6/25）, religious workers （18.79%, 31/165） and herdsmen（18.34%, 328/1 788）. In terms of education level, the morbidity and the rate of serum antibody were both highest in the uneducated（5.04%, 41/4 779; 18.34%, 359/1 958, respectively）. In terms of residential pattern, the morbidity and the rate of serum antibody were both highest in those who were settled in winter and nomadic in summer （8.25%, 227/2 753; 19.48%, 158/811, respectively）. There were significant differences in the morbidity and the rate of serum antibody in aspects of residential region, sex, age, occupation, education level and residential pattern (P<0.05 or P<0.01). In 872 rodents detected, the Echinococcus hydatid rate was 0.46% （4/872）, while in 809 cattle and sheep detected, the Echinococcus hydatid rate was 10.14% （82/809）. The fecal antigen positive rate in 838 samples of dog feces was 10.74%（90/838）. Conclusion: It shows a high morbidity of hydatid diesease and serum antibody positive rate in residents, a high Echinococcus hydatid rate in cattle and sheep, and a high fecal antigen positive rate in dogs in Yushu Prefecture.

[Survey on Echinococcosis in Maqing County of Qinghai Province].

OBJECTIVE: To understand the status of echinococcosis in Maqing County of Qinghai Province in order to facilitate echinococcosis control in this region. METHODS: Ultrasonic scanning and indirect hemagglutination assay were used to detect echinococcosis infection in residents >1 year old, according to the People's Republic of China Health Industry Standard--Diagnostic Criteria for Hydatid Disease (WS257-2006). Meanwhile, ELISA was used o detect the Echinococcus antigen in dog's feces collected in Youyun, Dangluo and Xiadawu townships. RESULTS: Ultrasonic scanning showed that the prevalence of hydatid disease in the residents was 7.4% (116/1 561), cystic hydatid disease 5.3% (82/1 561), alveolar hydatid disease 2.2% (34/1 561). The serum positive rate in human population was 23.8%(307/1 288). Of the 82 cases of cystic hydatid disease, 23 cases (28.1%) had the hydatid cyst with a diameter of >10 cm. The prevalence in males and females in the county was 5.3% (40/753) and 9.4% (76/808), respectively (P<0.05). Among populations with different occupations, the highest prevalence of hydatid disease fell into houseworkers (11/61, 18.0%), monks (5/41, 12.2%) and herdsmen (84/758, 11.1%). Among the age groups, the groups of >60 years (24/132, 18.2%) and 30-40 years (31/302, 10.3%) had higher prevalence of hydatid disease. The three townships with the higher prevalence were Youyun (29/247, 11.7%), Changmahe (6/63, 9.5%) and Dangluo (54/645, 8.4%). Of the 199 samples of dog's feces, 54 were positive for Echinococcus antigens (27.1%), with a positive rate of 40.4% (23/57) in Youyun towship, being significantly higher than in the other two (P<0.05). CONCLUSION: Maqin county is a co-endemic area of cystic echinococcosis and alveolar echinococcosis. The prevalence is higher in females and those over 60 years-old.

An alternative mebendazole formulation for cystic echinococcosis: the treatment efficacy, pharmacokinetics and safety in mice.

BACKGROUND: Cystic echinococcosis is a serious zoonotic infection worldwide caused by metacestodes of Echinococcus gruanulosus. Mebendazole and albendazole are the only two drugs used in the treatment of this disease with cure rates only about 30% due to the poor oral absorption. Thus an alternative treatment for this disease is needed. METHODS: A mebendazole oily suspension (MBZ-OS) was prepared and orally administrated to mice infected with echinococcus cysts for 8 months at 12.5 mg/kg and 25 mg/kg for 14 consecutive days. Mebendazole suspended in 1% tragacanth (MBZ-1% tragacanth) served as treated control. In addition, liver and serum samples were collected from these treated mice (25 mg/kg) for histopathology examination and liver function test. For pharmacokinetic analysis, plasma, parasite (cyst wall and cyst fluid) and tissue samples were collected at 0.25, 0.5, 1, 2, 4, 8, 16 and 24 h after orally administrating MBZ-OS and MBZ-1% tragacanth to E. granulosus-infected mice at 25 mg/kg. These samples were then processed and quantitatively analyzed by HPLC. RESULTS: The administration of MBZ-OS resulted in a treatment efficacy with the cyst weight reductions higher than 80%, significantly better than the corresponding MBZ-1% tragacanth groups. The better treatment efficacy of MBZ-OS was related to the higher drug concentration in plasma, parasites and tissues. It was also shown that the injury of the liver was not significantly altered by taking MBZ-OS compared to the untreated control. CONCLUSION: These findings demonstrate that MBZ-OS is a promising new formulation of MBZ for treatment of hydatid diseases without showing significantly liver toxicity.

Trial occlusion to assess the risk of persistent pulmonary arterial hypertension after closure of a large patent ductus arteriosus in adolescents and adults with elevated pulmonary artery pressure.

BACKGROUND: No method is available to predict whether patients with patent ductus arteriosus (PDA) and severe pulmonary arterial hypertension (PAH) will show persistent postprocedural PAH (PP-PAH) after PDA closure. This study evaluated the usefulness of trial occlusion for predicting PP-PAH after transcatheter PDA closure in patients with severe PAH. METHODS AND RESULTS: Trial occlusion was performed in 137 patients (age ≥12 years) with PDA and severe PAH. All patients undergoing trial occlusion had a mean pulmonary artery pressure ≥45 mm Hg, pulmonary:systemic flow (Qp/Qs) ratio >1.5, and pulmonary:systemic resistance (Rp/Rs) ratio <0.7. A total of 135 patients (98%) showing stable hemodynamics during occlusion trial underwent successful device closure. Linear correlation analysis revealed weak or moderate relationships between the baseline and post-trial pulmonary artery pressures and pulmonary:systemic pressure (Pp/Ps) ratios. Patients were followed up for 1 to 10 years (median: 5 years). PP-PAH (systolic pulmonary artery pressure >50 mm Hg by Doppler echocardiography) was detected in 17 patients (13%), who displayed no significant differences in sex and age compared with patients without PP-PAH. According to discriminant analysis, the strongest discriminators between patients with and without PP-PAH were the baseline left ventricular end-diastolic volume and the baseline and post-trial systolic Pp/Ps ratios. In particular, a post-trial systolic Pp/Ps ratio >0.5 correctly classified 100% of the PP-PAH and non-PAH patients. CONCLUSIONS: Trial occlusion is a feasible method to predict PP-PAH in patients with PDA and severe PAH. A post-trial systolic Pp/Ps ratio >0.5 indicates a high risk of PP-PAH occurrence after device closure.

[Geographical distribution of echinococcosis among children in Qinghai Province].

OBJECTIVE: To analyze the epidemiological status of echinococcosis among children in three different zones of Qinghai Province. METHODS: B-ultrasound and ELISA were used in the survey to evaluate echinococcus infection among 6 to 15 year old children in the three zones, namely, Qinghai southern plateau, Qilian mountain-Hehuang valley and Chaidamu basin. RESULTS: The prevalence of echinococcus infection scanned by B-ultrasound and sera positive rate detected by ELISA in children were 1.5% (320/20 730) and 6.5% (1024/15 762) respectively, and the prevalence of cystic echinococcosis and alveolar echinococcosis by ultrasound were 1.0% (206/20730) and 0.6% (114/20730), respectively. The prevalence and sera positive rate were 9.5% (707/7 453) and 2.3% (269/11 618) in Qinghai southern plateau, 3.8%(289/7 544) and 0.6% (50/8 275) in Qilian mountain-Hehuang valley, and 3.7% (28/765) and 0.1% (1/837) in Chaidamu basin, respectively. The southern plateau showed the highest prevalence, with a significant statistical difference among the three areas (P < 0.01). The prevalence of alveolar echinococcosis was 1.0% (114/11 618) in the southern plateau, but no alveolar echinococcosis patients were found in other two areas. Correlation analysis showed that the prevalence increased with the altitude (r(s-e) = 0.96, P < 0.05, R2 = 0.93; r(p-e) = 0.82, P < 0.05, R2 = 0.67). CONCLUSION: The prevalence of echinococcosis among children shows an apparent geographical difference in Qinghai Province.

[Cloning and expression of echinococcus granulosus Eg18 and preliminary evaluation of immunological assay with recombinant antigen].

OBJECTIVE: To clone and express Echinococcus granulosus Eg18 gene and evaluate the immunoreactivity of the recombinant protein. METHODS: Eg18 coding sequence was amplified by RT-PCR using primers designed according to the sequence of Eg18 in GenBank from total RNA extracted from Echinococcus granulosus protoscoleces isolated from infected sheep in Qinhai Province and cloned into the prokaryotic expression vector pET-28a(+). The recombinant expression vector was transformed to Escherichia coli BL21 (DE) and induced to express by IPTG. The expressed products were analyzed by SDS-PAGE and purified with Ni-IDA agarose affinity chromatography. rEg18 was evaluated for its reactivity with the sera from the patients infected with hydatid and other helminthes by Western blotting and ELISA. RESULTS: The sequence of cloned Eg18 was completely identical wit the original sequences of Eg18 and Em18 deposited in GenBank. The recombinant protein strongly reacted to the sera from the patients with alveolar echinococcosis, cystic echinococcosis, and cysticercosis, and weakly reacted to the sera from the patients with nematodiasis, schistosomiasis and clonorchiasis. The detection of specific IgG4 was much more specific than that of IgG. CONCLUSION: Eg18/Em18 is the common antigen of cestode and its specific IgG4 is a serum marker of alveolar echinococcosis.

[Cloning, expression and immunodiagnostic evaluation of antigen EPC1 from Echinococcus granulosus].

OBJECTIVE: To clone and express EPCl gene of Echinococcus granulosus, and investigate its immunogenicity and diagnostic value. METHODS: Total RNA was extracted from hydatid cyst protoscoleces and EPC1 gene of Echinococcus granulosus was amplified by RT-PCR. The PCR product was cloned into pGEM-T vector, and then subcloned into the prokaryotic expression vector PET28a(+). The positive recombinants were transformed into Escherichia coli BL21 (DE3), and followed by expression of the protein induced by IPTG. The recombinant protein was identified by SDS-PAGE and Western blotting, and used to establish ELISA. Serum samples from patients with cystic echinococcosis (60 cases), alve-olar echinococcosis (37 cases), cysticercosis (16 cases), clonorchiasis sinensis (7 cases), schistosomiasis japonica (4 cases) and healthy persons (33 cases) were examined. RESULTS: The recombinant plasmid PET28a-EgEPC1 was identified by restriction enzyme digestion and sequencing. SDS-PAGE result showed that the recombinant containing recombinant plasmid PET28a-EgEPC1 expressed a soluble fission protein of EgEPC1 (about M, 11 000). The protein was recognized by pool sera of cystic echinococcosis patients. The overall sensitivity and specificity of diagnosis by ELISA for cystic echinococcosis were 78.3% (47/60), and 98.3% (59/60), respectively. The cross reaction with sera of alveolar echinococcosis was 40.5% (15/37). CONCLUSION: The recombinant EgEPC1 antigen has diagnostic value in cystic echinococcosis.

[Effect of control pattern with emphasis on canine deworming in a pilot of echinococcosis in highly endemic area, southern Qinghai Plateau].

OBJECTIVE: To evaluate the effect of control pattern with an emphasis on canine deworming in a pilot of echinococcosis in highly endemic area of southern Qinghai Plateau. METHODS: Four pasturing villages in Xiewu Township of Chengduo County were selected as pilot villages in August of 2008. Baseline survey on awareness of echinococcosis prevention knowledge among residents and status of dogs' infection (coproantigen ELISA) was carried out in the villages. After baseline survey, measures of minimizing the control unit, setting up 15th of each month as fixed canine purgation date (praziquantel 1-2 pill/dog), giving health education to residents, selecting and training control personnel, and mobilizing local residents to participate in control of echinococcosis were performed. In October of 2009, a survey was carried out with the same contents as baseline survey to evaluate the effect of the control pattern. RESULTS: After intervention, the awareness rate on echinococcosis prevention knowledge in the residents increased from 76.1% (172/226) in 2008 to 98.8% (237/240) (chi2=55.6, P<0.01) . The positive rate of coproantigen ELISA for canine echinococcosis decreased from 32.6% (43/132) to 4.2% (5/120) (chi2=32.9, P<0.01). CONCLUSION: The knowledge awareness on echinococcosis prevention in residents increased and infection rate in dogs decreased considerably after intervention.

Acute hemodynamic responses to adenosine and iloprost in patients with congenital heart defects and severe pulmonary arterial hypertension.

BACKGROUND: Detection of pulmonary vasoreactivity is important for the evaluation of patient with pulmonary arterial hypertension (PAH). The present study aimed to investigate the acute hemodynamic responses to adenosine and iloprost in patients with congenital heart defects (CHDs) and severe PAH. PATIENTS AND METHODS: From Mar 2007 to Nov 2009, 75 patients with severe PAH secondary to left-to-right shunt CHDs underwent acute vasodilator test using aerosolized iloprost (n = 50) or intravenous adenosine (n = 25). The hemodynamics were detected and analyzed. RESULTS: Decreased mean pulmonary arterial pressure (PAP) and pulmonary vascular resistance (PVR) were observed in 39 and 43 patients in the iloprost group, and in 16 and 19 patients in the adenosine group, respectively. However, the mean PAP was higher than 40 mm Hg in both groups. No significant difference was observed in the age and baseline hemodynamics between the patients with the decrease of PVR and mean pulmonary-to-aortic pressure (Pp/Ps) ratio greater than 10% and the remaining patients. Adenosine decreased both PAP and systemic arterial pressure significantly, while iloprost inhalation selectively reduced the PAP and increased the oxygen saturation of femoral arterial blood and the pulmonary-to-systemic flow (Qp/Qs) ratio. Compared with adenosine, iloprost caused a more profound decline in the Pp/Ps ratio, PVR and pulmonary-to-systemic vascular resistance ratio, and increase in the Qp/Qs ratio. CONCLUSIONS: The acute haemodynamic responses to adenosine and iloprost varied among the patients with CHDs and severe PAH. Different to adenosine, inhaled iloprost exerted selective pulmonary vasodilative effects and was beneficial for pulmonary gas exchange.

Transcatheter closure of congenital coronary artery fistulae: immediate and long-term follow-up results.

BACKGROUND: Transcatheter closure of coronary artery fistulae (CAF) has emerged as an alternative to surgery, but there are no long-term outcome results. OBJECTIVE: We report immediate and long-term results in 24 patients after transcatheter closure of congenital CAF. METHODS: A total of 24 patients aged 5 to 56 years old with congenital CAF underwent attempted percutaneous transcatheter closure using various devices between November 1998 and August 2008. The immediate closure results and clinical follow-up were reviewed. RESULTS: Of the 24 patients, 20 (83.3%) underwent successful transcatheter closure using various devices. An angiogram right after device deployment revealed complete occlusion in 15 patients (75%) and trivial- to mild- residual flow in 5 patients (25%). Four patients (20%) had transient ST-T wave changes after the procedure. The left ventricular end-diastolic volume decreased from 165+/-31.4 mm3 to 128.6+/-24.4 mm3 (P = 0.012) 24 hours after procedure, and the cardiothoracic ratio from 0.57+/-0.02 to 0.53+/-0.01 (P = 0.003). Follow-up was 100% complete and ranged from 3 months to 10 years. There were no early or late deaths. All patients were asymptomatic with complete closure of CAF except 1 patient (5%) who had a recurrence of shunt at 6-month follow-up, which was re-closed by percutaneous technique. CONCLUSION: Transcatheter closure of CAF is feasible and safe in anatomically suitable vessels and is a promising alternative to surgery in most patients.

[Epidemiological survey on echinococcosis in Darlag County of Qinghai Province].

OBJECTIVE: To make an epidemiological investigation on echinococcosis in Darlag County, Guoluo Tibetan Autonomous Prefecture of Qinghai Province. METHODS: Local participants were screened for echinococcosis using B ultrasound from August to September in 2007. IHA was carried out to detect antibody in human sera. Indirect ELISA using recombinant-AgB and Em18 antigen was conducted to further diagnose the human alveolar echinococcosis (AE) and cystic echinococcosis (CE) . The prevalence of echinococcosis in wild rodents, yaks, sheep and dogs was examined either by dissection or through slaughterhouses. Adult worms and hydatid cysts were detected by PCR-RFLP to discriminate 3 Echinococcus species and genotype of Eg. Dog feces were tested by double antibody sandwich ELISA method to confirm the coproantigen positive rate. RESULTS: 1723 people were examined by ultrasound and 236 were clinically diagnosed as hydatid diseases with an overall morbidity of 13.7%, of which 5.5% were CE and 8.2% were AE. Prevalence in males and females was 11.6% and 15.6% respectively with a statistically significant difference (chi2=7.0, P< 0.05) . Prevalence in herdsmen and monks/nuns was as high as 23.0% and 13.2%, respectively. Adult worms were found in 5 out of 9 stray dogs by necropsy. 27 of 239 pikas (Ochotona curzoniae) were infected by E. shiquicus (11.3%). CE prevalence in sheep and yaks was 26.4% and 5/16 respectively. The Eg genotype was G1 (sheep strain). CONCLUSION: Three species of Echinococcus, e.g. E. granulosus, E. multilocularis and E. shiquicus are all prevalent in Darlag County. The prevalence of both AE and CE in human population is high in the area. Domestic dogs are the primary definitive host for both E. granulosus and E. multilocularis.

[An epidemiological survey on echinococcosis in Zhiduo County of Qinghai Province].

The survey was carried out in July, 2006 in Zhiduo County. The IHA and ELISA positive rate in human population was 4.5% (42/933) and 8.2% (76/931) respectively. Ultrasonography revealed a morbidity of 3.4% (33/979) with 3.2% Echinococcus granulosus and 0.2% of E. multilocularis respectively. Animal dissection showed an infection rate of 15.1% (14/93) in pikas with one infected by E. shiquicus proved by molecular biology. Coproantigen rate by ELISA was 62% (12/193) in dogs and 35.7% (5/14) in wolves. The results indicated that Zhiduo County is a mixed endemic area for echinococcosis.

[Radiofrequency perforation and balloon valvuloplasty in infants with pulmonary atresia and intact ventricular septum].

OBJECTIVE: To investigate the efficacy and safety of percutaneous radiofrequency perforation and valvuloplasty in infants with pulmonary atresia with intact ventricular septum (PA/IVS). METHODS: Four infants (body weight 4 - 10 kg) aged 11 months, 9 months, 12 days and 9 months old, respectively, were hospitalized for dyspnea and cyanosis. All patients had a continuous murmur in the left second intercostal space. Doppler echocardiogram showed membranous pulmonary atresia with intact ventricular septum. Right ventriculogram showed a tripartite right ventricle, vasiform infundibulum, and membranous pulmonary valve atresia without ventriculocoronary connections. Descending thoracic aortogram showed good-sized confluent pulmonary arteries being filled from a ductus arteriosus. All the patients were taken up for radiofrequency perforation followed by a balloon dilatation. A 6F Judkins right coronary guiding catheter was positioned in the right ventricular outflow tract and under the atretic pulmonary valve membrane. The radiofrequency perforation catheter along with coaxial injectable catheter was then passed through the right coronary guiding catheter, using it as the guide to the imperforate membrane. The proximal end of the radiofrequency perforation catheter was then connected to radiofrequency generator. After the cusps of pulmonary valve were perforated, the coaxial injectable catheter was moved into the main pulmonary artery. A tiny floppy-tipped coronary guidewire was then passed through the coaxial injectable catheter into the main pulmonary artery and directed through the patent ductus arteriosus into the descending thoracic aorta or directed into pulmonary arteriola. Thereafter, serial balloon dilation catheters were introduced across the pulmonary valve, and dilations were sequentially performed with increasing balloon diameters. The balloon was dilated until the concave of the balloons disappeared. The radiofrequency energy (5 to 8 W) was delivered for 2 to 5 seconds once, but commonly twice, to perforate the valves. After a predilation with a 3 mm x 20 mm to 5 mm x 20 mm balloon at 6 - 14 atm pressure, the valve was subsequently dilated with 10 mm x 30 mm to 14 mm x 30 mm balloon once or twice. The duration of procedures was 120 to 150 min and exposure time was 25.4 to 43.9 min. RESULTS: The primary procedure was successful in all the infants except one who died early of cardiac perforation with tamponade. After a follow-up period ranging from 2 to 8 months (mean 4.3 m), the remaining 3 survivors achieved complete biventricular circulation. Two of them were awaiting occlusion of the patent ductus arteriosus and 1 needed right ventricular outflow tract reconstruction because of infundibular obstruction. CONCLUSION: PA/IVS consists of 0.7% to 3.1% of congenital heart defects. 85% of the untreated patients die within half a year. Surgical repair for the infants with PA/IVS is associated with a high mortality. In carefully selected patients with PA/IVS, radiofrequency perforation and balloon dilatation of the pulmonary valve is feasible and may represent a new alternative to surgery due to its low mortality and avoidance of cardiopulmonary bypass.