Patent Ductus Arteriosus Shunt Research Articles

Early Surgical Ligation Versus a Conservative Approach for Management of Patent Ductus Arteriosus That Fails to Close after Indomethacin Treatment

To examine whether a more conservative approach to treating patent ductus arteriosus (PDA) is associated with an increase or decrease in morbidity compared with an approach involving early PDA ligation. In January 2005, we changed our approach to infants born at age<or=27 weeks gestation who failed indomethacin treatment. We changed from an early surgical approach, in which feedings were stopped and all PDAs were ligated (period 1: January 1999 to December 2004; n=216) to a more conservative approach in which feedings continued and PDAs were ligated only if cardiopulmonary compromise developed (period 2: January 2005 to August 2009; n=180). All infants in both periods received prophylactic indomethacin therapy. The 2 periods had similar rates of perinatal/neonatal risk factors and indomethacin failure (24%), as well as ventilator management and feeding advance protocols. The conservative approach (period 2) was associated with decreased rates of duct ligation (72% vs 100%; P<.05). Even though infants subjected to this approach were exposed to larger PDA shunts for longer durations, the rates of bronchopulmonary dysplasia, sepsis, retinopathy of prematurity, neurologic injury, and death were similar to those in period 1. The overall rate of necrotizing enterocolitis was significantly lower in period 2 compared with period 1. These findings support the need for new controlled, randomized trials to reexamine the benefits and risks of different approaches to PDA treatment.

Quantification of Left to Right Shunt in Patent Ductus Arteriosus by Color Doppler

Ultrasound is a reliable tool to diagnose patent ductus arteriosus in premature infants but no reliable noninvasive method exists to quantify ductal flow. The aim of this study was to quantify the size of the shunt via persistent ductus arteriosus from pixel counts in color Doppler flow images. A cotton band was placed around the ductus arteriosus of newborn lambs to adjust the magnitude of flow. For flow measurements, ultrasonic transit time flow probes were applied around the ascending aorta and ductus arteriosus. Twenty-four different flow states were attained in four newborn lambs. An Acuson Sequoia scanner equipped with a 7 MHz transducer was used to register Doppler data and images with maximal color distribution during diastole in the pulmonary artery longitudinal sections (PALS). Each image-pixel was matched with the color velocity bar and the pixels were assigned to the corresponding flow velocity. The total area showing color relative to the area of the PALS correlated well with the amount of ductal flow ( r = 0.87, r 2 = 0.75, p < 0.001). When Qp/Qs was >1.4:1, more than 40% of the area in PALS in diastole exhibited color information. Similarly, the color pixel velocities squared correlated with the size of the shunt. Quantification of the percentage of pixels in a color Doppler registration via a computer-based analysis shows a high correlation with the size of ductal shunting. (E-mail: solweig.harling@med.lu.se)

Comparison of 0.052-Inch Coils vs Amplatzer Duct Occluder for Transcatheter Closure of Moderate to Large Patent Ductus Arteriosus

Percutaneous device closure is now the widely accepted management technique for patent ductus arteriosus (PDA). In the present study, current practice of closing moderate to large PDA using the Amplatzer duct occluder (ADO) was compared with the previous experience using 0.052-inch coils. From August 1997 to September 2006, 76 patients were selected for either 0.052-inch coils or ADO implantation. Selection criteria were a minimal diameter of > or =2.5 mm and angiographic type A, C, D or E. In group I, 21 patients received 0.052-inch coils in a multiple coil strategy for PDA closure. In group II, 55 patients underwent ADO device implantation. The age, weight, hemodynamics, minimal PDA diameter and shunt size were insignificantly different between groups. However, group I had a higher rate of failed implantation and device embolization, and the immediate and 24-h closure rates (38.9% vs 81.8%, P<0.05; 72.3% vs 96.4%, P<0.05) favored group II. ADO implantation is safer and more effective than the 0.052-inch coil strategy for transcatheter closure of moderate to large PDA.

Effects of a patent ductus arteriosus on postprandial mesenteric perfusion in premature baboons.

Superior mesenteric artery flow increases after a feeding to meet the intestines' increased metabolic demands. Although a patent ductus arteriosus can affect superior mesenteric artery perfusion in nonfeeding infants, there is no information about its effects on the hyperemic response that follows a feeding. Our goal was to study the effects of a patent ductus arteriosus on superior mesenteric artery perfusion in preterm baboons. Preterm baboons were delivered at 67% gestation and ventilated for 14 days. Enteral feedings were begun and advanced per protocol. Feeding studies were performed between days 10 and 14. Thirty-one studies were performed in animals with a closed ductus; 21 studies in those with a moderate patent ductus arteriosus shunt (pulmonary-to-systemic blood flow ratio>or=2:1). Two-dimensional echocardiographic and Doppler examinations were performed before and 10 and 30 minutes after a feeding. The groups were similar in birth weights, feeding volumes, and age at time of study. During the preprandial period, baboons with a moderate patent ductus arteriosus had significantly lower blood pressures and systemic blood flows than animals with a closed ductus. Preprandial superior mesenteric artery-blood flow velocities did not differ between the open and closed ductus groups. Animals with a closed ductus increased their superior mesenteric artery-velocities (diastolic and mean) and decreased their superior mesenteric artery relative-vascular-resistance (mean blood pressure/mean superior mesenteric artery-velocity) by 10 minutes after the feeding. By 30 minutes after the feeding, the values were returning to their preprandial values. In contrast, in baboons in the patent ductus arteriosus group, there were no significant changes in superior mesenteric artery-velocity or resistance after the feeding, and superior mesenteric artery-velocities were significantly lower than those in the closed ductus group. A moderate patent ductus arteriosus shunt limits the ability of the preterm newborn baboon to increase its postprandial mesenteric blood flow velocity. We speculate that this may interfere with its ability to meet increased intestinal metabolic demands and may contribute to feeding difficulties.

Patent ductus arteriosus ligation in neonates: preoperative predictors of poor postoperative outcomes

Purpose The purpose of this study was to identify preoperative predictors of adverse outcomes in infants undergoing surgical ligation of patent ductus arteriosus (PDA). Methods Charts of all neonates who underwent PDA ligation at Texas Children's Hospital (Houston, TX) between 2001 and 2006 were retrospectively reviewed with specific attention to preoperative clinical characteristics, echocardiographic details, operative morbidity, and postoperative outcomes. Infants with other cardiac anomalies or right-to-left or bidirectional PDA shunt were excluded. Results Eighty-two neonates were included (mean gestational age, 27 weeks; mean birth weight, 1000 g). There were no intraoperative complications. Preoperative symptoms related to respiratory insufficiency, hypotension, apnea, and pulmonary edema improved after ligation ( P < .001). Birth weight, age at ligation, and indomethacin use did not correlate with postoperative outcome; however, lower gestational age, lower blood pressure, and lower shunt peak velocity predicted longer time to extubation by multiple analysis techniques ( P < .0001). Linear regression (controlling for gestation, birth weight, and mean arterial pressure) showed inverse correlation between peak velocity and postoperative days on the ventilator (95% confidence interval, 47.18 to −12.25; P = .001). Conclusion The PDA ligation can be accomplished safely; however, some neonates have prolonged recovery. Lower gestational age and low peak velocity (<2.6 m/s) at the PDA shunt correlate with lengthened ventilator requirement after surgery.

Pharmacological Closure of Patent Ductus Arteriosus: Effects on Pulse Pressure and on Endothelin-1 and Vasopressin Excretion

Widened pulse pressure is a classic sign of significant left-to-right shunting patent ductus arteriosus (PDA), but little evidence supports this statement in the early life of premature infants with respiratory distress syndrome (RDS) needing nonsteroidal anti-inflammatory drugs (NSAIDs), the pharmacological treatment for PDA. Pulse pressure and urinary endothelin-1 (ET-1) and arginine vasopressin (AVP) vasoactive factors involved in the transitional circulation were measured before and after the NSAIDs treatment of 46 RDS premature infants receiving either ibuprofen (n = 22) or indomethacin (n = 24), with 28 responders and 18 nonresponders to the first NSAIDs course. We found that following pharmacological PDA closure, systolic and diastolic blood pressure significantly increased, maintaining a stable pulse pressure. However, when pharmacological closure failed, the trend (nonsignificant) was for a more consistent increase in systolic than in diastolic blood pressure, which determined a statistically significant widening pulse pressure. In addition, urinary ET-1 excretion rates decreased significantly after PDA closure, whereas persistent more aggressive pharmacological therapy failed. Urinary AVP excretion rates decreased insignificantly after therapy, uninfluenced by the efficacy of the drugs. We concluded that widened pulse pressure is a clinical sign of failed PDA pharmacological closure in RDS premature infants. ET-1 levels remain elevated when NSAIDs fail to interrupt left-to-right PDA shunting that complicates recovery from RDS.

Ductus Arteriosus Ligation and Alveolar Growth in Preterm Baboons With a Patent Ductus Arteriosus

Premature newborn baboons [125 d (67%) gestation], exposed to a moderate-size patent ductus arteriosus (PDA) [pulmonary-to-systemic blood-flow-ratio (Qp/Qs) = 1.8] for 14 d, have impaired pulmonary function and arrested alveolar development and surface area when compared with age matched fetuses (140 d gestation). Pharmacologic closure of the PDA reduces the detrimental effects of preterm delivery on pulmonary function and surface area. We used preterm baboons (delivered at 125 d gestation and ventilated for 14 d) to study the effects of surgical PDA ligation on pulmonary function and alveolar surface area. After ligation (on day of life 6), ligated animals had lower Qp/Qs ratios [Qp/Qs (ligated, n = 10) = 1.00 +/- 0.04; (nonligated, n = 12) = 2.05 +/- 0.17; mean +/- SD] and higher systemic blood pressures than nonligated control animals. Ventilation and oxygenation indices did not differ between the groups, during either the pre- or postoperative periods. Alveolar surface area measurements were made by digital image analysis and compared with measurements made from fetal lungs at 125 d (n = 6) and 140 d (n = 7) gestation. PDA ligation failed to improve the postnatal arrest in alveolar surface area. In contrast with pharmacologic closure of the PDA, surgical closure failed to improve either pulmonary function or alveolar surface area in baboons with a moderate PDA shunt.

William Osler, Maude Abbott, Paul Dudley White, and Helen Taussig: The Origins of Congenital Heart Disease in North America

In 1965, Helen Taussig traced the evolution of knowledge of congenital heart disease (CHD) during the 20th century, beginning with the William Osler-Maude Abbott lineage at McGill University in Montreal, Canada. Osler encouraged Abbott in her CHD pathologic observations. Abbott's London Exhibit (1934) preceded her classic text Atlas of Congenital Cardiac Disease (1936). Taussig's friendship with Abbott (1935) began in Boston; Abbott brought Taussig to meet Paul Dudley White whose text Heart Disease (1931) featured Abbott's work. Taussig visited Abbott (Montreal 1938). Abbott's statistical approach was based on post-mortem malformations; Taussig's concern was why CHD babies died. Abbott (1927) suggested surgery for a patent ductus arteriosus; Taussig conceived of creating a patent ductus arteriosus shunt to improve lung blood flow in cyanotic "blue babies". Surgeon Alfred Blalock and Taussig collaborated with the blue baby shunt operations (1944-1945), opening the field of cardiac surgery in cyanotic babies. Taussig's Congenital Malformations of the Heart text came 2 years later. Sequential contributions by Osler, Abbott, White, and Taussig were landmarks in the evolution of knowledge of CHD in North America.

Patent Ductus Arteriosus and Its Treatment as Risk Factors for Neonatal and Neurodevelopmental Morbidity

The purpose of this work was to determine whether the reported association between neonatal morbidities and a patent ductus arteriosus is because of the left-to-right patent ductus arteriosus shunt itself, the therapies used to treat it, or the immaturity of the infants who are likely to develop a patent ductus arteriosus. A total of 446 infants (<28 weeks' gestation) were treated with the same patent ductus arteriosus care-oriented protocol, and logistic regression analysis was used to examine the effects of several patent ductus arteriosus-related variables (presence of a symptomatic patent ductus arteriosus, the number of indomethacin doses used, the ductus response to indomethacin, and the use of surgical ligation) on the incidence of retinopathy of prematurity, necrotizing enterocolitis, chronic lung disease, death, and neurodevelopmental impairment. Most of the predictive effects that the presence of a patent ductus arteriosus and its treatment had on neonatal morbidity could be accounted for by the infants' immature gestation. Use of surgical ligation, however, was significantly associated with the development of chronic lung disease and was independent of immature gestation, other patent ductus arteriosus-related variables, or other perinatal and neonatal risk factors known to be associated with chronic lung disease. These findings add to the growing uncertainty about the benefits and risks of surgical ligation during the neonatal period.

Angiographic classification of patent ductus arteriosus morphology in the dog

Objectives To characterize angiographic morphology and minimum internal transverse diameter of left-to-right shunting patent ductus arteriosus (PDA) in a large series of dogs. Background PDA is the most common congenital cardiac malformation in the dog. Transarterial ductal occlusion is increasingly performed to close this defect. While accurate assessment of ductal morphology and luminal diameter is important to assure optimal occlusion using catheter-delivered devices, such information is currently limited. Animals, materials and methods In 246 dogs representing 31 breeds with left-to-right shunting PDA, right lateral selective aortic angiograms were recorded and reviewed. Results PDA morphology conformed to four general phenotypes (types I, IIA, IIB, and III) which varied according to degree of ductal tapering, and the presence, absence, or location of abrupt ductal narrowing. Minimum internal ductal diameter for all dogs averaged 2.9 mm (median, 2.5 mm; range, 1.0–9.5 mm) and was not correlated to age or body weight. There was no significant difference in minimum internal diameters between types I, IIA or IIB PDA, whereas, type III PDA was significantly wider ( p = 0.024) than other phenotypes. The most frequently-encountered variant (type IIA) was identified in 54.4% of cases (average minimum internal diameter, 2.3 mm [median, 2.2 mm; range, 1.0–5.5 mm]). Conclusions PDA angiographic morphology was categorized based upon the degree, presence, or absence of ductal narrowing, and the location of ductal attenuation. When planning PDA repair, this information should assist planning, selection and deployment of transcatheter occluding devices.

Original investigation of right-to-left shunting patent ductus arteriosus in an Irish setter puppy

A six-month-old, entire female, Irish setter was presented with a two-month history of progressive hindlimb weakness and collapse on exercise. Thoracic auscultation revealed a soft systolic murmur and a split second heart sound. Differential cyanosis and polycythaemia were not observed. Right-to-left shunting patent ductus arteriosus (r-PDA) was confirmed on contrast echocardiography (“bubble study”) and selective right ventricular angiography. Comparison of blood gases from the metatarsal and auricular artery confirmed the presence of differential hypoxia. This technique is not known to have been described previously in the diagnostic investigation of r-PDA in dogs.

Transarterial Coil Embolization for Canine Patent Ductus Arteriosus Occlusion

Left to right shunting patent ductus arteriosus (PDA) is the most common canine congenital heart defect. If not occluded PDA is associated with high morbidity and mortality. Historically, surgical ligation has been the standard method of correction. Although highly successful, surgical ligation is associated with some operative morbidity and mortality. More recently, minimally invasive transcatheter techniques have been employed for PDA occlusion. Transarterial PDA coil embolization is a safe, cost effective, less invasive alternative offered by many specialty centers for PDA occlusion. This procedure involves catheterization of the femoral artery under general anesthesia. An angiogram is then performed to delineate PDA morphology and facilitate coil selection. Coils are commercially available and composed of surgical stainless steel with prothrombotic poly-Dacron fibers. Coils are advanced through a catheter into the PDA under fluoroscopic guidance until satisfactory angiographic occlusion is documented. Patients are then recovered and released the following day. This procedure requires substantial technical expertise and specialized equipment.

右-左短絡を呈した猫の動脈管開存症の1例

Physical examination of a 32-month-old male Japanese domestic cat with a 3-month history of exercise intolerance and hind-limb weakness revealed a grade-IV/VI systolic murmur at the left heart base. Echocardiogaphy and cardiac catheterization resulted in a diagnosis of right-to-left shunting patent ductus arteriosus with severe pulmonary hypertension. Exercise restriction and treatment with a vasodilator improved the Clinical signs immediately. The patient was doing well and free of clinical signs 24 months after initial administration. This is a case of successful control of canine Eisenmenger syndrome with medication.

Long-term follow-up of dogs with patent ductus arteriosus.

Postocclusion survival data from dogs with left-to-right shunting patent ductus arteriosus (PDA) was available from 80 dogs, diagnosed from 1990 to 2000. Of these, 37 had undergone a procedure to close the ductus and were re-evaluated at the time of this study; clinical data from the follow-up examination was compared with that from the original examination. Radiographically, the right ventricle remained apparently enlarged, and the aortic bulge associated with dilation of the descending aorta did not disappear after closure. On M-mode echocardiography, left ventricular chamber diameter in diastole and systole and left ventricular posterior wall in systole decreased significantly. Mitral endocardiosis was a common feature. Residual flow was evident in 46 per cent of the animals. Late closure occurred in 8 per cent of the dogs, and trivial recanalisation in 19 per cent. The maximum survival time postclosure was 168 months and, after non-occlusion, 114 months, suggesting that dogs with PDA follow an unpredictable course. However, there was a significant difference in survival times between the corrected and non-corrected group.

Percutaneous angiography of Patent Ductus Arteriosus in dogs: techniques, results and implications for intravascular occlusion

Objectives To evaluate the percutaneous angiography and the morphology of patent ductus arteriosus (PDA) in dogs. Background In contrast to surgical ligation the knowledge of angiographic morphology is necessary for intravascular PDA occlusion. Methods Forty-nine dogs with a left to right shunting PDA were included in a three-year, prospective study. In 43 dogs with a body weight ≥ 3.0 kg a percutaneous approach to brachial artery was tested. In six miniature dogs (< 3.0 kg) placement of angiographic catheter from femoral vein antegrade through the PDA was studied. Angiographic morphology and dimensions of PDA were analyzed. Results Percutaneous approach to brachial artery was performed successfully in 41/43 (95%) dogs, in the remaining 2 dogs this approach was not possible and the femoral artery had to be used. Two dogs did not survive the procedure. Arterial bleeding was not a problem in any of the 39 cases in which percutaneous brachial artery catheterization was performed. Two dogs developed transient radial nerve paralysis that resolved 4 to 6 days later. The transvenous technique was successful in all 6 small dogs. In 39 dogs there was an elongated conical duct (type E). A conical duct (type A) was found in nine dogs and one dog had a PDA with two constrictions (type D). The mean PDA minimal diameter was 3.78 ± 1.55 mm (range 1.5 to 6.9), in 20/49 dogs (41%) the minimal PDA diameter measured more than 4.0 mm. Conclusions Percutaneous catheterization of the brachial artery using a vascular introducer is feasible and entails minimal risk of hemorrhage. Angiographic evaluation of the ductus arteriosus is easily performed with this technique, but coilimplantation is not possible by this approach. The frequency of PDA-types is different in dogs and humans and the PDA minimal diameter is larger in dogs.

Review of left-to-right shunting patent ductus arteriosus and short term outcome in 98 dogs.

The case records of 98 dogs with a left-to-right shunting patent ductus arteriosus (PDA) were reviewed. There were 35 breeds represented, with a female to male ratio of 3:1. Forty per cent of the dogs were older than one year at initial presentation and 31 per cent had clinical signs attributable to PDA. A left heart base continuous murmur of grade IV/VI or higher was noted in 90 per cent of the dogs. On electrocardiography, the most common abnormalities were tall R waves (63 per cent) and deep QII waves (62 per cent). The radiographic triad of dilation of the descending aorta with enlargement of the main pulmonary artery segment and left atrium, typical of PDA, was noted in only 26 per cent of cases. Two-dimensional (2D) and M-mode echocardiography detected left atrial enlargement (35 per cent) and an increased left ventricular diameter in diastole (82 per cent) and systole (84 per cent) as the most common abnormalities. Doppler echocardiography demonstrated increased aortic outflow velocities in 66 per cent of cases. The overall short-term successful outcome in this study was 95 per cent. There was no significant difference between surgical ductal ligation using a standard technique or the Jackson-Henderson technique in terms of survival, occurrence of haemorrhage or residual shunting. The number of interventional procedures used in this study was too low for statistical comparison, but there appeared to be a trend towards a higher rate of residual shunting and a lower fatality rate using a coil occlusion technique.

Early reopening and recanalization after successful coil occlusion of the patent ductus arteriosus

Background Controversy exists regarding early reopening and recanalization after successful (complete) coil occlusion of the patent ductus arteriosus (PDA). Methods Patients with successful PDA coil occlusion were reviewed with regard to PDA size and type, coil size, number of coils, and delivery technique. Follow-up echocardiograms at <24 hours, 6 months, and >12 months were reviewed for residual PDA shunt, left pulmonary artery (LPA) stenosis, and aortic obstruction. Results Successful coil occlusion was achieved in 94 patients. On the initial (<24 hours) echocardiogram, 76 of 92 (83%) had complete PDA occlusion, 5 of 92 (5%) had mild LPA stenosis, and no patient had aortic obstruction. Follow-up at 6 months was available in 70 patients, 57 with complete occlusion on the initial echocardiogram. PDA reopening was found in 3 of 57 patients (5%). Larger PDA diameter was associated with residual shunt (2.40 ± 0.40 mm versus 1.87 ± 0.53 mm; P <.01). Disagreement between the initial and 6-month echocardiogram was found in 11 of 70 patients (16%). Intermediate follow-up (median, 30 months; range, 12 months to 5.3 years) was available in 46 patients, 38 with complete occlusion on the 6-month echocardiogram. No patient (0 of 38) with a normal echocardiogram at 6 months developed recanalization, LPA stenosis, or aortic obstruction. Conclusion These data suggest that: (1) routine echocardiography immediately after PDA coil occlusion is unnecessary; (2) early PDA reopening is uncommon; and (3) PDA recanalization does not occur if complete echocardiographic closure is documented 6 months after coil occlusion. Additional follow-up examination in these patients may not be necessary. (Am Heart J 2002;143:889-93.)

Quantification of left-to-right shunt in patent ductus arteriosus with the PISA method

Direct Doppler echocardiographic calculation of shunt flow in patent ductus arteriosus (PDA) may be difficult because the orifice area is not well visualized. We used proximal isovelocity surface area (PISA) method to calculate the effective shunt orifice area and the shunt volume in a patient with PDA. The PISA calculation correlated well with shunt estimation by echocardiographic volumetric methods and by oximetry. (J Am Soc Echocardiogr 2002;15:376-8.)

First‐Pass Nuclear Angiocardiography in the Evaluation of Patent Ductus Arteriosus in Dogs

First‐pass nuclear angiocardiography (FPNA) was performed in 5 normal dogs and in 19 dogs with left‐to‐right shunting patent ductus arteriosus (PDA). Affected dogs were evaluated before and after an occlusion procedure (surgical ligation or transarterial coil embolization). Two methods of analysis were used to evaluate the pulmonary time‐activity curves and assess the magnitude of the shunt. One method involved the calculation of a simple count ratio (C2: C1). The other method used gamma variate modeling to estimate the ratio of pulmonary to systemic blood flow (QP:QS). Values for normal dogs (mean ± SD) were C2:C1 = 0.39 ± 0.11 and QP:QS = 1.10 ± 0.03. Values for affected dogs were C2:C1 = 0.59 ± 0.17, QP:QS = 2.01 ± 0.46 before intervention and QP:QS = 1.21 ± 0.17, C2:C1 = 0.42 ± 0.12 after intervention. Both methods detected significant differences between normal and affected dogs (QP:QS, t‐test, P &lt; .001; C2:C1; t‐test; P= .018) and between affected dogs pre‐ and postocclusion (QP: QS, paired t‐test, P &lt; .001; C2 : C1, paired t‐test, P= .002). However, QP : QS was a better separator of normal from affected animals. First‐pass nuclear angiocardiography, by the gamma variate method, may be a useful, adjunct diagnostic test in evaluation of animals with left‐to‐right shunting PDA, particularly in animals with residual shunting after an occlusion procedure.

Hydroxyurea for Treatment of Polycythemia Secondary to Right‐to‐Left Shunting Patent Ductus Arteriosus in 4 Dogs

Four adult dogs with polycythemia secondary to reversed patent ductus arteriosus (rPDA) were treated with hydroxyurea, a myelosuppressive agent, for 6-22 months. Regardless of initial hematocrit, clinical signs attributed to the presence of polycythemia improved with hydroxyurea treatment. Chronic hydroxyurea therapy (40-50 mg/kg PO q48h) was well tolerated in this group of animals; mild, clinically silent thrombocytopenia and leukopenia were detected in some animals but resolved with decreased dosage or dose frequency. Chronic hydroxyurea therapy may provide an alternative to repeated phlebotomy for therapy of polycythemia secondary to rPDA.