Prediction of Symptomatic Patent Ductus Arteriosus in Preterm Infants Using Doppler and M-mode Echocardiography

ABSTRACT. To investigate whether the development of symptomatic patent ductus arteriosus could be predicted, 26 preterm infants dependent on mechanical ventilation were examined daily with Doppler and M-mode echocardiography until 3 days after birth. The presence or absence of a hemodynamically significant ductus shunt, as judged from echocardiographic criteria, was tested for predictive power in terms of sensitivity, specificity and total error rate. Out of the 26 infants 13 developed symptomatic patent ductus arteriosus at a median age of 5 days (range 2–8). These 13 infants developed echocardiographic evidence of a large shunt at a median age of 2 days (range 1–3). The sensitivity of prediction was 18, 46 and 100% at 1, 2 and 3 days after birth. The specificity was 80, 92 and 85% and the total error rate was 52, 32 and 8%. Thus, accurate prediction was possible 3 days after birth.     

控制性降压麻醉在动脉导管未闭术中的应用

目的探讨硝普钠(SNP)复合芬太尼或瑞芬太尼在动脉导管未闭(PDA)手术中行控制性降压麻醉的有效性和安全性。方法先天性PDA患儿60例用SNP复合芬太尼(A组)或瑞芬太尼(B组)麻醉,监测不同时间血流动力学变化和并发症。结果B组心率稳定,降压迅速,SNP用量少,血流动力学变化和苏醒恢复状况均优于A组。结论瑞芬太尼持续麻醉能强化SNP的降压效果,减少并发症发生。     

Transplacentally-Administered Enalapril Inhibits the Spontaneous Constriction of the Ductus Arteriosus in the Newborn Rat

ABSTRACT Pregnant Wistar rats were given orally enalapril maleate (EM), an angiotensin-converting enzyme (ACE) inhibitor, 15–60 min prior to Caesarean operation and the diameter of the ductus arteriosus (DA) in the newborn rats was calibrated at intervals after delivery. The caliber of the DA in control newborn rats gradually decreased to less than 10% of the initial value by 90 rnin after delivery. The DA calibers of the newborn rats treated with 50 or 200 mg/kg EM in utero were larger than the controls at any time interval up to 90 rnin and the difference from the control value was significant for at least 30 rnin after delivery when the drug was given to the dam 30 rnin prior to Caesarean section. The present study has demonstrated that transplacentally-administered enalapril inhibits the spontaneous constriction of the neonatal rat DA and supports the view that ACE inhibitors should not be used late in pregnancy.     

Amplatzer Angled Duct Occluder for Closure of Patent Ductus Arteriosus Larger than the Aorta in an Infant

Transcatheter closure of patent ductus arteriosus (PDA) by Amplatzer duct occluder is the treatment of choice. However, closure of very large ducts in infants with low weight is a challenge for the interventionalist because a large device may obstruct the aorta or left pulmonary artery. Difficulty is also encountered in advancing the device around the curve of the right ventricular outflow tract toward the pulmonary artery; this curve is tight, more or less at a right angle in infants, leading to kinking of the sheath, which increases fluoroscopic time. This is the first reported case of a very large PDA (8.7 mm), larger than the aorta (8.2 mm), successfully closed by an Amplatzer angled duct occluder in an infant weighing 5 kg.     

早产儿动脉导管未闭的临床研究

目的　观察早产儿动脉导管未闭 (PDA)发生率、影响因素及血流动力学的变化 ,提供监测及干预治疗的建议。方法　 86例胎龄 2 8～ 3 6周、无呼吸机治疗 (未用或已停用 )的早产儿 ,出生 2～ 5d行首次超声心动图检查。对诊断为PDA的早产儿动态超声心动图监测。结果　生后 3～ 4d超声心动图诊断PDA 2 2例 ,胎龄 (3 3 .1± 2 .0 )周。生后 8.5d 2 0例复查 ,16例动脉导管自行关闭 ;4例PDA早产儿经治疗 ,动脉导管关闭 2例 (1例吲哚美辛 ;1例动脉导管再开放 )。最终遗留PDA 3例。单因素及多因素Logistic回归分析发现 ,出生体质量越低 ,PDA发生机率越高 (χ2 =2 .890 7　P =0 .0 891) ;生后窒息及严重疾病增加PDA发生的危险性 (χ2 =4.3 72 9　P =0 .0 3 65 ;χ2 =11.65 90　P =0 .0 0 0 6)。PDA存在使早产儿左心房 /主动脉根内径比值增高 (1.0 8± 0 .18vs 1.0 0± 0 .0 7　P =0 .0 48) ,心功能良好。结论　平均胎龄 3 3周、平均日龄 3d、一般状况较好的早产儿超声心动图诊断PDA机率 2 5 .6% ,85 %早产儿PDA可自行关闭。低出生体质量、出生窒息、严重疾病及症状性PDA发生或持续均是高危因素。     

The Silent Ductus Arteriosus in Idiopathic Respiratory Distress Syndrome

Among 425 pre-term low birthweight babies who survived more than 48 hours there were 130 with idiopathic respiratory distress syndrome, 73 of whom received ventilation for their disease. The ductus arteriosus was considered patent by clinical criteria in 41 of these babies, all but 1 of whom had a murmur. Of the remaining 32 infants there were 2 babies only who died and both were found to have a patent ductus arteriosus which had not been detected clinically. Another baby died whilst being ventilated for idiopathic respiratory distress syndrome and although autopsy information is not available it seems likely that factors other than a patent ductus arteriosus caused death. The mean age of murmur detection in those ventilated infants considered to have a patent ductus arteriosus was 6 days (range 2–19). Infants without a murmur or other features of a ductus arteriosus did not require to be ventilated beyond day 7 with the exception of the 2 fatalities already mentioned. Thus, relying on clinical criteria and particularly on the presence of a murmur, if sought often, rarely results in missing or seriously delaying the diagnosis of patent ductus arteriosus in babies with severe idiopathic respiratory distress syndrome     

婴儿期动脉导管未闭介入治疗效果及随访情况

目的评价在婴儿期应用Amplatzer封堵器治疗动脉导管未闭（PDA）的临床效果。方法婴儿期PDA患儿37例应用Amplatzer封堵器行动脉导管封堵术。年龄（8.7±3.3）个月;体质量（8.6±3.5）kg。主动脉侧位造影确定动脉导管的形态和导管最窄处直径,选择封堵器。经静脉途径置入封堵器。术后24 h,1、6、12个月行胸片和超声心动图随访。结果血管造影测定导管最窄处直径（3.3±1.5）mm。术后即刻完全封堵19例（54.29%）,术后24 h超声心动图检查完全封堵者为31例（88.57%）,术后1个月超声心动图检查完全封堵者34例（97.14%）,术后6和12个月超声心动图检查示封堵成功的患儿均无残余分流。手术时间（57±43）min,X线透视时间（23.0±14.9）min。结论Amplatzer导管封堵器治疗婴儿期PDA是一种安全有效的方法,但应注意该年龄组患儿解剖学特点,防止并发症的发生。     

动脉导管未闭患儿介入治疗前后血浆N末端脑利钠肽水平及心功能变化

目的应用心脏超声技术及检测血浆N末端脑利钠肽（NT-proBNP）水平,探讨经皮动脉导管未闭（PDA）封堵术对心功能影响。方法PDA患儿55例,术前按照小儿心衰改良Ross标准分为无心衰组31例,轻度心衰组14例,中重度心衰组10例（重度心衰1例）。选择年龄、体质量相匹配健康儿童15例作为健康对照组。应用酶联免疫吸附法测定血浆NT-proBNP水平。同时测定左室舒张末期容量指数（LVEDVI）、左室收缩末期容量指数（LVESVI）、左室射血分数（LVEF）、左室缩短分数（LVFS）等反映心室功能及负荷的超声心动图指标。结果1.PDA患儿术前LVEDVI、LVESVI均显著高于健康对照组（Pa〈0.01）,且各组间随着心功能严重程度增加而显著升高（P〈0.01）。2.术前血浆NT-proBNP水平随着心功能严重程度增加而升高,中重度心衰组高于轻度心衰组（P〈0.01）,轻度心衰组高于无心衰组（P〈0.01）,无心衰组与健康对照组比较无统计学差异（P〉0.05）。3.PDA患儿术后3个月血浆NT-proBNP水平、LVEDVI、LVESVI均较术前显著降低（Pa〈0.01）,接近健康对照组水平（P〉0.05）。4.血浆NT-proBNP水平与LVESVI（r=0.653P〈0.01）、LVEDVI（r=0.741P〈0.01）呈正相关,而与LVEF、LVFS等无显著相关性（P〉0.05）。结论PDA堵闭术后3个月在临床症状和反映左室功能超声指标明显改善同时,术前高血流动力学负荷对心室细胞影响也逐渐恢复。     

介入治疗儿童动脉导管未闭132例随访观察

目的了解介入治疗儿童动脉导管未闭(PDA)术后并发症的发生情况及其演变。方法通过询问病情及行胸片、心电图及心脏超声等辅助检查,对所完成的132例PDA患儿进行4a跟踪随访,随访时间为(28±16)个月。其中45例使用Amplatzer进口封堵器,87例使用深圳先健国产封堵器。结果术后第2天,经胸超声(TTE)证实128例封堵器位置良好,4例存在残余分流(4/132例),其中1例发生溶血(1/132例),经治疗后,症状消失。随访1个月,所有残余分流均消失。股动脉血栓形成1例(1/132例),经溶栓治疗,股动脉搏动完全恢复。9例出现短时间发热(9/132例)。随访过程中6例出现不明原因头痛。2例发生严重事件,1例术后6个月出现长期发热,TTE发现封堵器表面有赘生物形成,最终经外科开胸治疗痊愈。另1例于术后18个月死于不明原因的肺动脉高压。结论介入治疗儿童PDA是一种安全、有效方法,但同时也存在许多并发症,术后需认真而长期的随访观察。     

介入治疗对动脉导管未闭患儿心肌的影响

目的研究PDA介入治疗是否会导致心肌损伤和炎性反应,分析介入治疗致心肌损伤的影响因素。方法选取2008年10月-2010年8月在本院住院的37例PDA患儿。于术前,术后即刻,术后4 h、2 d、3 d、7 d,采集静脉血,应用ELISA法检测其血清心肌肌钙蛋白I(cTnI)和CRP水平,并记录年龄、缺损大小、曝光时间和造影剂量等相关危险因素。应用SPSS 13.0软件进行统计学处理。结果 PDA介入治疗术后即刻、4 h、2 d和3 d cTnI水平分别为0.08(0.00～1.37)μg.L-1、0.09(0.00～0.68)μg.L-1、0.06(0.00～0.96)μg.L-1及0.04(0.00～0.96)μg.L-1,较术前[0.05(0.00～0.58)μg.L-1]升高;术后7 d[0.04(0.00～0.44)μg.L-1]已低于术前水平,高峰出现在术后4 h,与术前cTnI水平比较差异有统计学意义(P<0.05);术后各时段cTnI均低于正常水平。于术后4 h CRP[0.36(0.00～28.00)mg.L-1]开始升高,至术后3 d达峰值[7.79(0.20～52.40)mg.L-1],继之下降;与术前[0.30(0.00～17.06)]相比,术后3 d及7 d CRP水平[4.10(0.20～34.57)mg.L-1]均显著升高(Pa<0.05);术后各时段CRP均低于正常水平。年龄、曝光时间、缺损大小和造影剂量等与cTnI变化无明显相关性。结论 PDA介入治疗未引起明显心肌损伤及炎性反应,是一种安全的治疗手段。     

Changes in Intracranial Arterial Blood Flow Velocities during Surgical Ligation of the Patent Ductus Arteriosus

ABSTRACT. A combined continuous and range-gated Doppler instrument was used to assess intracranial arterial blood flow velocity changes in infants and neonates undergoing surgical ligation of the Ductus Arteriosus (DA). Continuous recordings during DA closure in six infants (3.5-10 months old), showed an abrupt increase in diastolic blood flow velocity simultaneous with an increase in systolic and diastolic arterial blood pressure. In five infants, these changes were followed by a rapid fall in systolic and diastolic blood pressure without a concomitant change in blood flow velocity, which may be secondary to a rapid fall in intracranial vascular resistance. The mean blood flow velocity increase following DA closure was 27 % (8-43 %) and the changes in diastolic and mean blood flow velocity were significant (p<0.01). In seven preterm neonates (24-28 weeks) studied before and after surgery, a mean blood flow velocity increase of 50 % (14-115 %) (p<0.01), mainly due to an increase in diastolic blood flow velocity (p<0.01), was recorded. These rapid intracranial hemodynamic changes during surgical DA closure should be taken into consideration when selecting techniques for DA closure.     

维生素A对胎兔动脉导管发育的影响

目的研究维生素A(VitA)对胎兔动脉导管发育的影响,为防治早产儿动脉导管未闭(PDA)寻找新的途径。方法孕兔8只随机分为4组,VitA 5000 IU/d,受孕d25服用1次(A组),孕d25、d26连续服用2次(B组),孕2周后隔天服用(C组)和对照组服用生理盐水(D组)。取胎兔动脉导管固定,切片、HE染色,观察导管内膜增殖情况,测定导管内钙浓度。结果A、B、C组导管内膜增殖程度较D组明显增加,A、B、C组导管内钙浓度明显增加。结论VitA能增加导管内钙浓度,促进胎兔动脉导管发育。     

经导管Amplatzer封堵器和外科手术治疗动脉导管未闭对照试验的Meta分析

目的评估经导管Amplatzer封堵器治疗动脉导管未闭(PDA)的疗效,为临床应用提供指导。方法采用Meta分析方法,对国内外有关经导管Amplatzer封堵器和外科手术治疗PDA的对比临床研究进行综合定量分析,采用RevMan4.2.2软件进行数据处理,计算各组技术失败率、并发症及严重并发症发生率、残余分流率等的相对危险度(RR)及其95%可信区间(CI)。结果符合纳入标准共5篇文献,总样本量349例。经导管Amplatzer封堵器组技术失败率高于外科手术组[5组对照试验(CT),349例,3.0%vs0,RR=4.29,95%CI(0.77,23.95)],但无显著性差异(P=0.10);并发症发生率低于外科手术[5组CT,343例,3.1%vs38.0%,RR=0.11,95%CI(0.05,0.23)](P<0.00001);严重并发症发生率显著低于手术组[5组CT,343例,0.5%vs6.0%,RR=0.23,95%CI(0.06,0.90)](P=0.03);Amplatzer封堵器组治疗后即时残余分流率高于手术组[4组CT,304例,16.3%vs0,RR=16.06,95%CI(3.0,86.12)](P=0.001);出院时残余分流率虽高于手术组,但无显著性差异(2.5%vs0,P=0.33)。结论经导管Amplatzer封堵器治疗PDA尽管成功率低于外科手术,但其创伤小、并发症发生率低、疗效与手术相仿,随着封堵器及其输送系统的不断改进和完善,在适应证范围内经导管Amplatzer封堵器治疗可作为PDA外科手术治疗的替代方法。     

动脉导管未闭直径的不同测量方法在介入治疗中的应用

目的 评价经胸超声心动图(TTE)与心血管造影在介入治疗中测量动脉导管未闭(PDA)直径的应用价值.方法 拟行PDA堵闭的PDA患儿52例.应用TTE观察降主动脉与肺动脉间相通的动脉导管的位置、直径及长度,测量PDA最窄处直径;心血管造影选用猪尾管,行左侧位造影,测量其最窄径线.并对2种方法的测量值进行比较.采用SPSS 12.0软件进行统计学分析.结果 心血管造影显示52例PDA患者中,漏斗型45例,管型5例,漏斗型并管型、PDA结扎手术后残余分流各1例;TTE显示漏斗型46例,管型4例,窗型、PDA结扎手术后残余分流各1例.心血管造影测量的PDA直径为(3.72±2.51) mm,显著＜TTE测量值(4.47±2.31) mm,二者比较差异具有显著性意义(t=5.17 P＜0.05).结论 TTE可用作术前病例的初步筛选,心血管造影决定PDA的分型,PDA直径需结合心血管造影与TTE测量综合分析,术后有无残余分流及随访依靠TTE.TTE与心血管造影在PDA介入治疗中互相补充,缺一不可.     

Challenges Encountered During Closure of Patent Ductus Arteriosus

Transcatheter closure of patent ductus arteriosus (PDA) was one of the first interventions established in invasive cardiology and is now more than 30 years old. The challenges for successful closure with the first devices in children consisted of handling the rather large introducer sheaths and stiff application systems. Today, interventional closure can be performed with different types of plugs, occluders, and coils. Thus, beyond infancy, transcatheter closure can be successfully performed in almost all cases. Challenging from the technical standpoint can be the closure of window-type ducts, in which excessive protrusion of the device into the descending aorta should be avoided, as well as the closure of tubular ducts, in which secure anchoring of one or more devices in the vessel can be very difficult. For the combination of a coarctation and an open duct, different strategies can be considered. In selected cases, use of a covered stent can be helpful. From the physiological standpoint, open ducts in patients with pulmonary hypertension with or without concomitant congenital heart diseases can be challenging because testing of vasoreactivity with temporarily blocked duct and the option of subsequent treatment with vasodilators may be necessary prior to making the decision whether the patient may benefit from definitive duct occlusion or not. Large ducts in infants less than 8 kg can be difficult to treat due to a relative mismatch of introducers, plugs, or occluders to the small anatomic dimensions. The implantation of multiple coils can be associated with a higher risk of device embolization. Unfortunately, for the large group of preterm infants with very low body weights and large ducts of tubular shape there is currently no standardized interventional therapy available.     

Lack of Constrictive Effects of Cocaine on the Fetal Ductus Arteriosus in the Rat

Cocaine (12.5 or 25 mg/kg) was administered intraperitoneally to pregnant rats 15 min to 12 hr prior to Caesarean section on day 20 of gestation. The fetuses were immediately frozen and serially sectioned, and the diameter of their ductus arteriosus (DA) was calibrated. The DA was patent in all the fetuses examined and the DA caliber was not significantly different between the control and the cocaine-treated groups at any time interval after the cocaine dosing. It was concluded that cocaine has no constrictive effects on the fetal DA in the rat.     

Transcatheter Closure of Patent Ductus Arteriosus Among Native High-Altitude Habitants

Increased prevalence of patent ductus arteriosus (PDA) at high altitude (HA) is a known occurrence. Transcatheter treatment of patients with PDA living at a HA is assessed in this study. Thirteen consecutive patients (all habitants of La Paz, Bolivia) underwent transcatheter closure of PDA. The minimal diameter of PDA was 5.8 (1.5–11) mm and the mean pulmonary artery pressure was 37 (7–80) mm Hg. In 12 patients, the Amplatzer Duct Occluder (ADO) was used; in one child with PDA with a 1.5-mm diameter, a detachable coil was implanted. All procedures, except for one, were completed successfully. The ADO (diameter: 12/10 mm) implantation failed in one child with pulmonary hypertension because the device could not be properly secured in position in a 6-mm PDA. Subsequent surgery was performed without any complications. No residual shunt after 24 h was observed in any case after treatment. No complications were encountered during the procedure and follow-up of 1.5 (from 0.1 to 2.8) years. PDA in native residents of high land have different physiopathologies and anatomies. ADO appears to be a suitable device for transcatheter occlusion for most such patients. Interventional cardiology in countries with residents at high altitudes can be helpful in addressing this issue.     

Usefulness of Indomethacin for Patent Ductus Arteriosus in Full-Term Infants

The aim of this retrospective study was to evaluate the effectiveness of indomethacin therapy for patent ductus arteriosus (PDA) in full-term infants. The patients were 41 full-term infants with a PDA birth weight (BW) > or =2500 g and a gestational age (GA) > or =37 weeks. The echocardiographic evaluation and medical management of PDA in these infants was similar to that for PDA in low-birth-weight infants. Indomethacin (0.2-0.25 mg/kg/dose) was given intravenously at 12-24-hour intervals within 23 days of birth. Of the 41 infants, 12 showed complete closure, and 13 showed improvement of clinical symptoms. These 25 infants were classified as the responder group (61%). The other 16 infants, who did not show improvement in clinical symptoms, were classified as the nonresponder group. Statistical analysis revealed no difference between the two groups regarding GA, BW, Apgar score at 1 minute, minimum diameter of the DA before treatment, the average age at the initiation of treatment, and DA flow pattern. No severe adverse reactions were observed in any infant. Indomethacin therapy appears to be an effective medical treatment option for PDA in full-term symptomatic infants prior to considering surgical treatment.     

Transient Dynamic Subaortic Stenosis in Premature Neonates After Patent Ductus Arteriosus Ligation

We describe 2 premature infants with PDA that did not respond to medical therapy and required surgical ligation. Both infants developed transient dynamic subaortic obstruction that resolved without specific therapy. This may have occurred due to sudden changes in the left ventricular volume.