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PubMed2003

Transcatheter closure of the patent ductus arteriosus.

Patent ductus arteriosus (PDA) is one of the most common congenital heart defects. Although surgery is still required in symptomatic neonates, the majority of older infants and children can undergo safe and effective transcatheter device closure on an out-patient basis. First described in 1967, over the past four decades, numerous devices have been specifically developed for this purpose. This article will review the current status of transcatheter therapy. The experience with each device is detailed and issues and controversies are reviewed.

Cardiac Catheterization↗
PubMed1997

[Patent ductus arteriosus and pulmonary artery endarteritis].

We describe a seven year old girl with echocardiographic diagnosis of pulmonary artery endarteritis as a complication of a patent ductus arteriosus, confirmed at surgery. This case illustrates the necessity of complete surgical resection of the infectious source as a way to avoid other complications such as pulmonary embolism.

Child↗
PubMed1998

[Overall experience with percutaneous occlusion of patent ductus arteriosus].

PURPOSE: To evaluate the overall experience of our institution with percutaneous occlusion of the patent ductus arteriosus. METHODS: Since December/92, 150 patients underwent 178 procedures (85-Rashkind technique; 87-Gianturco coils; 6-Duct Occlud). Median age was 6.5 years (1 to 57). Mean minimum ductal diameter was 3.05 +/- 1.24 mm (1 to 8). Clinical and echocardiographic evaluations were performed periodically. RESULTS: Adequate implantation was achieved in 143 (95.3%) patients. Prevalence of immediate residual shunting was 52.1%, falling to 15.9% during follow-up. This figure decreased to 5.2% after new additional procedures. Umbrella and coil embolization occurred in 1 and 12 procedures, respectively. Hemolysis and mild stenosis of left pulmonary artery were observed in one patient each. There was no mortality. CONCLUSION: This therapeutic modality is safe and efficacious with good follow-up results.

Child, Preschool↗
PubMed1981

Division of patent ductus arteriosus by "isthmus taping method".

"Isthmus taping method" as the safe and simple technique for division of patent ductus arteriosus (PDA), along with surgical and follow-up results were reported. 175 patients with PDA and without other cardiac anomalies were operated by this technique. Most of the patients were operated by junior surgeons as a first step in cardiac surgery. The left chest was entered through posterolateral thoracotomy in the third or fourth intercostal space. Tapes were placed around the isthmus of aorta and PDA. Intercostal arteries were not divided. PDA was divided in-between Potts' clamps. Pulmonary and aortic stumps of the PDA were closed with two rows of continuous over and over suture. Of the 175, one patient (0.6%) with pulmonary hypertension died of postoperative respiratory failure. No surgical hazards of bleeding were noted. No deaths were noted among 131 patients without pulmonary hypertension. Follow-up results in 174 patients up to 14 years were excellent.

Adolescent↗
PubMed1983

Progressive pulmonary vascular disease after surgery in a case of patent ductus arteriosus with pulmonary hypertension.

In a 15-month-old girl with patent ductus arteriosus (PDA) with pulmonary hypertension, division of the PDA was undertaken, but she died of heart failure 7 months post-operatively. Morphometric study of biopsy and autopsy lungs showed that medial hypertrophy and pulmonary intimal lesions developed markedly after surgery. Severe pulmonary hypertension and hypoxemia were present preoperatively. The pulmonary hypertension remaining postoperatively and aggravated pulmonary hypoxemia are thought to have caused postoperative constriction of the pulmonary vessels and to bring about unusual medial hypertrophy. Since it is known that marked hypertrophy of the media can easily cause vasospasms, it is thought that, in the present case, the smooth muscle cells of the media became necrotic, which brought about damage to endothelial cells. Such damage, in turn, led to the development of occlusive pulmonary vascular disease.

Ductus Arteriosus, Patent↗
PubMed1984

Severe pulmonary vascular disease consisting of ventricular septal defect and patent ductus arteriosus. A case diagnosed as the indication for total correction by the hemodynamic study.

A 12-year-old girl with ventricular septal defect, patent ductus arteriosus and pulmonary hypertension was hemodynamically diagnosed as the indication for total correction by the initial cardiac catheterization. However, histologic assessment by lung biopsy revealed the terminal stage of plexogenic pulmonary arteriopathy, i.e. plexiform lesions, dilatation lesions and fibrinoid necrosis of the media which denied the possibility of corrective surgery. We would like to stress that the open lung biopsy should be performed when the hemodynamic study indicates marginal operability, especially in older children and adults in order to investigate the grade of occlusive pulmonary vascular disease.

Child↗
PubMedDate not supplied

Long-term clinical management of right-to-left ("reversed") patent ductus arteriosus in 3 dogs.

A small number of dogs with patent ductus arteriosus (PDA) have right-to-left flow of blood through the ductus, leading to polycythemia and clinical signs associated with hyperviscosity. Three dogs with right-to-left-shunting PDA are described. Treatment consisted solely of phlebotomy, performed on an outpatient basis when indicated by exacerbation of clinical signs, for a total of 11-68 times on each dog. Each treatment entailed the removal of a mean of 19% (maximum 28%) of circulating blood volume, divided into 2 phlebotomies several hours apart, without intravenous fluid replacement. Subjectively, marked clinical improvement was noted. Intermittent clinical signs decreased in frequency and severity in all dogs. Adverse effects were rare (1 for 98 phlebotomies) and reversible. Dogs lived > 2 to > 8 years during treatment. Outpatient phlebotomy without fluid replacement was safe, and was associated with subjective improvement and prolonged survival in these dogs.

Animals↗
PubMedDate not supplied

Transvenous embolization of small patent ductus arteriosus with single detachable coils in dogs.

Transvenous embolization of small patent ductus arteriosus (PDA; < or = 4 mm) with a single detachable coil was attempted in 24 dogs (median age 5.7 months, range, 2.6-65.5 months; median body weight 5.5 kg, range, 1.5-30.0 kg). Angiographic imaging of the duct and pressure measurements were made before and after embolization. The minimal ductal diameter was 2.7 +/- 0.7 mm. In all dogs, a single coil was employed regardless of residual shunting. Ten dogs (PDA minimal diameter range, 1.5-2.2 mm) received a 5-mm coil, and 14 dogs (PDA minimal diameter range, 2.9-3.6 mm) received a 8-mm coil. After coil embolization the angiographic shunt grade decreased significantly (n = 20, P < .001). Residual shunts were assessed by angiography 15 minutes after and by Doppler echocardiography 1-3 days and 3 months after the intervention. In the dogs treated with the 5-mm coils the residual shunt rate was low (0%, 10%, and 0% for angiography and Doppler echocardiography at 1-3 days and 3 months, respectively), in contrast to the dogs treated with the 8-mm coils (91%, 79%, and 67% for angiography and Doppler echocardiography at 1-3 days and 3 months, respectively). After 3 months, no residual murmur was found in dogs treated with the 5-mm coils (0/7), in contrast to murmurs in 5 of 12 (42%) dogs treated with the 8-mm coils. Despite incomplete closure in these dogs, volume loading of the left heart decreased in all dogs. Pulmonic or aortic coil embolism did not occur. Analysis of initial results shows that single detachable coil embolization is possible in all dogs with a small PDA (< or = 4 mm), but only very small PDA (< or = 2.5) could be treated effectively, and for the moderate PDA (2.6-4.0 mm) longer coils or multiple coils may be necessary to achieve complete occlusion.

Angiography↗
PubMedDate not supplied

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 < .001; C2:C1; t-test; P = .018) and between affected dogs pre- and postocclusion (QP:QS. paired t-test, P < .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-fight shunting PDA, particularly in animals with residual shunting after an occlusion procedure.

Angiocardiography↗
PubMedDate not supplied

Transarterial coil embolization of patent ductus arteriosus in small dogs with 0.025-inch vascular occlusion coils: 10 cases.

Patent ductus arteriosus (PDA) is the most common congenital cardiac disease in the dog and generally leads to severe clinical signs, including left-sided congestive heart failure. Historically, definitive treatment consisted of surgical ligation; however, the use of vascular occlusion devices by minimally invasive techniques has gained popularity in veterinary medicine during the past decade. Adequate vascular access is a major limiting factor for these minimally invasive techniques, precluding their use in very small dogs. The clinical management of PDA with 0.025-in vascular occlusion coils in a minimally invasive transarterial technique in 10 dogs is described. The dogs were small (1.38 +/- 0.22 kg), were generally young (6.70 +/- 5.74 months), and had small minimal ductal diameters (1.72 +/- 0.81 mm from angiography). Vascular access was achieved, and coil deployment was attempted in all dogs with a 3F catheter uncontrolled release system. Successful occlusion, defined as no angiographic residual flow, was accomplished in 8 of 10 (80%) dogs. Successful occlusion was not achieved in 2 dogs (20%), and both dogs experienced embolization of coils into the pulmonary arterial tree. One of these dogs died during the procedure, whereas the other dog underwent a successful surgical correction. We conclude that transarterial PDA occlusion in very small dogs is possible with 0.025-in vascular occlusion coils by means of a 3F catheter system and that it represents a viable alternative to surgical ligation. The risk of pulmonary arterial embolization is higher with this uncontrolled release system, but this risk may decrease with experience.

Animals↗
PubMedDate not supplied

Pulmonary embolization of vascular occlusion coils in dogs with patent ductus arteriosus.

Transcatheter coil embolization of patent ductus arteriosus (PDA) was performed in 206 dogs between 1994 and 2003 at Texas A&M University, of which 7 (3%) had embolization of coils to the pulmonary vasculature. Thoracic radiographs indicated that coils were located in the right pulmonary artery in 6 of the 7 dogs. Pulmonary perfusion scans were available for review in 5 dogs, and moderate perfusion defects were observed in the right caudal lung lobe in 4 dogs within 24 hours of embolization. Perfusion deficits observed initially in 2 of the dogs resolved on perfusion scans performed at 6 months and 3.1 years. One dog did not have evidence of focal perfusion defects on a perfusion scan performed 4.5 months after embolization. All pulmonary embolizations occurred during the procedure. Attempts at retrieval of coils were unsuccessful in the 2 dogs in which it was attempted. No short- or long-term clinical complications were observed in any of the dogs with pulmonary embolization. We conclude that pulmonary embolization of vascular occlusion coils is an uncommon event and is not typically associated with adverse clinical effects in dogs with PDA.

Animals↗
PubMedDate not supplied

Immediate and late outcomes of transarterial coil occlusion of patent ductus arteriosus in dogs.

Records from dogs (n = 125) that underwent attempted transarterial coil occlusion of patent ductus arteriosus (PDA) at the University of California, Davis, between 1998 and 2003, were reviewed, and a subset of these dogs (n = 31) in which the procedure was performed at least 12 months earlier were reexamined to determine long-term outcome. Coil implantation was achieved in 108 dogs (86%). Despite immediate complete ductal closure in only 34% of dogs, the procedure was hemodynamically successful as evidenced by a reduction in indexed left ventricular internal diameter in diastole (LVIDd; P < .0001), fractional shortening (P < .0001), and left atrial to aortic ratio (LA: Ao; P = .022) within 24 hours. Complete ductal closure was documented in 61% of dogs examined 12 to 63 months after coil occlusion. Long-standing residual ductal flow in the other 39% of dogs was not associated with increased indexed LVIDd or LA: Ao and was not hemodynamically relevant. Repeat intervention was deemed advisable in only 4 dogs with persistent (n = 1) or recurrent (n = 3) ductal flow. Complications included aberrant embolization (n = 27), death (n = 3), ductal reopening (n = 3), transient hemoglobinuria (n = 2), hemorrhage (n = 1), aberrant coil placement (n = 1), pulmonary hypertension (n = 1), and skin abscessation (n = 1). Serious infectious complications did not occur despite antibiotic administration to only 40% of these dogs. Transarterial coil occlusion was not possible in 14 dogs (11%) because of coil instability in the PDA and was associated with increased indexed minimum ductal diameter (P = .03), LVIDd (P = .0002), LVIDs (P = 0.001), and congestive left heart failure (P = .03) reflecting a relatively large shunt volume.

Animals↗
PubMed2004

Are the economics of pharmaceutical research and development changing?: productivity, patents and political pressures.

Pharmaceutical research and development (R&D) competition in the 1980s and 1990 s was characterised by rising R&D expenditures, favourable returns to innovators and the introduction of many new classes of drugs with high social benefits. However, in the past 3 years, the number of new drug introductions has been well below the historical trend, while the cost per new drug continues to increase. In addition to lagging R&D productivity, the industry has been characterised by other economic and policy uncertainties. These include a wave of early patent challenges and growing political pressure to contain pharmaceutical expenditures. This paper examines the consequences of these developments.

Drug Approval↗
PubMed1997

Patent ductus arteriosus with combined valvular disease at age 91.

This report describes a 91-year-old patient with patent ductus arteriosus (PDA) complicated by combined valvular disease (CVD) (aortic and mitral stenosis, and aortic, mitral, pulmonic and tricuspid regurgitation). This patient seems to be the oldest living female with PDA and CVD hitherto reported in the medical literature. The patient developed several bouts of congestive heart failure which were treated medically. She not only has survived without surgical management, but is still enjoying her life at age 91. The features of PDA in the elderly are reviewed.

Aged↗
PubMed2005

Pharmaceutical research and development and the patent system.

The pharmaceutical industry routinely exaggerates its expenditures on research and development, but it does spend billions annually. But not all R&D is equally important. The patent-based system provides incentives to invest heavily in marketing and marketing-related measures masquerading as research. Innovators are rewarded with a marketing monopoly, and this drives what kind of research they do and what practices they follow to profit from their products. It is a system that creates incentives for marketing more than for research, which inevitably drives the marketing mission to corrupt the R&D process.

Biomedical Research↗
PubMed2006

Video-assisted thoracoscopic clipping of patent ductus arteriosus: close to the gold standard and minimally invasive competitor of percutaneous techniques.

OBJECTIVE: To review our 12-year experience in video-assisted thoracoscopic surgery (VATS) for patent ductus arteriosus. METHODS: VATS was performed in 743 patients. Three groups were compared: 24 low-birth-weight infants (LBWIs), 676 children between 2.5-25 kg and 43 boys > 25 kg. A diameter of > 8 mm was the main contraindication. For 85 consecutive patients, hospital stay underwent cost analysis. RESULTS: Median age was 1.6 years (range 5 days-33 years) and median weight 9.0 kg (range 1.2-65 kg). Mortality was nil. Median operative time was 20 min and hospital stay 2 days. Residual patency at discharge was 0% in LBWIs, 0.7% in children, and 4.7% in boys (P = NS) and 0, 0.3, and 4.7% at follow-up (P = 0.001). Persistent recurrent laryngeal nerve dysfunction was recorded in 4.2% of LBWIs, 0.3% of children and 0% of boys (P = 0.012). Total mean cost was Euro 5954 +/- 2110. CONCLUSIONS: The success rate of VATS clipping compares favorably with the thoracotomic approach but without chest wall trauma and it may have a very favorable cost-effective therapeutic balance compared to transcatheter techniques.

Adolescent↗
PubMed2003

Use of a self-expanding occluding stent for nonsurgical closure of patent ductus arteriosus in dogs.

OBJECTIVE: To evaluate the clinical application of a catheter-delivered, self-expanding occluding stent for closure of patent ductus arteriosus (PDA) in dogs. DESIGN: Prospective study. ANIMALS: 23 client-owned dogs weighing at least 3 kg (6.6 lb). PROCEDURE: Dogs were evaluated by physical examination, electrocardiography, thoracic radiography, and 2-dimensional, M-mode, spectral and color-flow Doppler echocardiography to confirm the diagnosis and obtain baseline measures. Shunt severity and ductal size and anatomy were established by means of angiography. With fluoroscopic guidance, the occluding stent, attached to a delivery cable, was maneuvered though the right side of the heart into the ductus via a prepositioned introducer sheath. After angiographic verification of appropriate stent placement, the delivery cable was detached, and the introducer sheath was withdrawn. Closure of the PDA was evaluated by means of angiography 15 minutes after stent deployment and by echocardiography 1 and 3 months after the procedure. RESULTS: There were no operative deaths. There were 2 deployment failures, both attributable to avoidable operator errors. Angiography performed after stent deployment indicated PDA closure in 13 of 20 (65%) dogs. There were 2 postoperative deaths in dogs with heart failure; both deaths were thought to be unrelated to use of the occluding stent. Complete PDA closure, determined by Doppler color-flow echocardiography, was evident in 17 of 19 dogs within 3 months and in 1 additional dog within 1 year of stent deployment, resulting in closure in 18 of 19 dogs completing the study protocol. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that a catheter-delivered occluding stent can be used successfully to close PDAs in dogs.

Angiography↗
PubMed2004

Cardiogenic hypertrophic osteopathy in a dog with a right-to-left shunting patent ductus arteriosus.

A 5-year-old castrated male Shetland Sheepdog was examined because of progressive bilateral hind limb thickening. Cyanosis of the preputial mucous membranes was evident, whereas the oral mucous membranes had a normal color. A well-structured, palisade-like periosteal reaction with no underlying bone destruction was evident on radiographs of the hind limbs. The radiographic changes were consistent with hypertrophic osteopathy (HO). Severe right-sided cardiomegaly was seen on thoracic radiographs, and a diagnosis of patent ductus arteriosus with right-to-left shunting was made by means of echocardiography and contrast echoaortography. The cyanotic heart disease was believed to be the cause of the HO. Hypertrophic osteopathy has been associated with a number of diseases in animals and humans. In humans, congenital heart defects that cause cyanosis are among the most common causes of HO.

Animals↗