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At least 1,207 records · Page 67Linked to original sources
PubMed1992

Simplified muscle-sparing thoracotomy for patent ductus arteriosus ligation in neonates.

To reduce operative morbidity we have developed a simplified muscle-sparing thoracotomy that provides excellent exposure for patent ductus arteriosus ligation in neonates. Operative time has not increased and seroma formation has not occurred. Improved functional and cosmetic results as well as less postoperative pain may be obtained by preserving the latissimus dorsi and serratus anterior muscles.

Constriction↗
PubMed1992

False aneurysm as a late complication of division of a patent ductus arteriosus.

A 58-year-old male patient who had a huge false aneurysm as a late sequela of division of patent ductus arteriosus was surgically managed with success. It is noteworthy that 24 years had elapsed from the initial operation until recognition of the aneurysm. The pathogenesis and method of the surgical treatment are discussed.

Aortic Aneurysm↗
PubMed1996

Incidence of vocal fold paralysis in infants undergoing ligation of patent ductus arteriosus.

BACKGROUND: Left-sided, iatrogenic vocal fold paralysis (IVFP) secondary to recurrent laryngeal nerve injury is a potential complication of ligation of patent ductus arteriosus (PDA). This study investigates specific risk factors associated with IVFP. METHODS: A retrospective chart review was performed for all infants 12 months of age or younger who underwent operative PDA closure at the University of Iowa from January 1, 1991, to January 1, 1994. RESULTS: Six cases of IVFP were diagnosed in 68 infants who underwent PDA ligation using clips (52.9%), suture ligatures (41.2%) or both (5.9%). Compared with infants without postoperative IVFP, infants with IVFP were smaller at birth (0.9 versus 2.3 kg; p < 0.001) and more premature (gestational age, 26.3 versus 33.8 weeks; p < 0.001), and were smaller (1.1 versus 3.4 kg; p < 0.001) and younger (31.9 versus 88.4 days; p < 0.001) at operation. Weight gain from birth to operation was significant only in infants without postoperative IVFP (p < 0.05). Although the overall incidence of IVFP in all infants undergoing PDA closure was 8.8%, five of the six cases (83.3%) of IVFP occurred in extremely low birth weight infants, ie, those weighing 1 kg or less at birth. Among the cohort of extremely low birth weight babies undergoing operation, the incidence of IVFP was 22.7%. Iatrogenic vocal fold paralysis was associated only with the use of surgical clips; however, because clips were used in 90.9% of the premature infants requiring PDA ligation, it was not possible to establish whether suture ligature is a safer technique. CONCLUSIONS: This study demonstrates that the single major risk factor for IVFP after ligation of PDA is birth weight less than 1 kg.

Birth Weight↗
PubMed1989

Prostaglandin E2 in the lung lavage fluid of premature newborns before and after surgical or medical closure of a patent ductus arteriosus.

To analyze the role of prostaglandin E2 in maintaining ductal patency in premature newborns, we measured the PGE2 concentration in the lung lavage fluid of nine patients within 24 h before and 4-8 h after surgical ligation of a patent ductus arteriosus and in two patients before and after closure of the ductus following intravenous indomethacin. The concentration of PGE2 ranged from 240 to 3770 pg/ml (mean 1666 +/- 1256 pg/ml) before operative intervention and show a significant decrease to 0-300 pg/ml (mean 93 +/- 106 pg/ml, P less than 0.001, Student's two-tailed t-test) within a few hours after ligation of the ductus arteriosus. The same significant decrease could be seen in two patients with successful indomethacin therapy (0.25 mg/kg in three doses/day) with concomitant ductus closure. In contrast, when indomethacin was given in a reduced dose (0.1 mg/kg in three doses/day), only a slight effect on PGE2 synthesis could be seen without closure of ductus arteriosus. We suggest that the fall of PGE2 levels in lung lavage fluid reflects the local synthesis in the ductus arteriosus itself and is responsible for the decrease induced by surgical ligation or pharmacological inhibition by indomethacin.

Bronchoalveolar Lavage Fluid↗
PubMed1993

Increased platelet activating factor in the tracheal aspirates from neonates with patent ductus arteriosus.

We investigated platelet-activating factor (PAF) in the tracheal aspirate from 3 intubated low birth weight infants with symptomatic patent ductus arteriosus (PDA). PAF increased with the onset of symptomatic PDA and decreased to the control range soon after the ductal closure. The concentration of PAF in 26 samples taken during symptomatic PDA (median 16 pg/micrograms lipid phosphorus, range 1.4-1,200 pg/micrograms lipid phosphorus) was significantly higher than that of 31 samples from the same three patients during the periods without symptomatic PDA (median 1.9 pg/micrograms lipid phosphorus, range 0-12 pg/micrograms lipid phosphorus; P < 0.001). All 3 infants later developed chronic lung disease. These results suggest that large shunting PDA provokes PAF release to the air way of the neonate and that PAF might play a role in chronic lung disease developing after symptomatic PDA.

Ductus Arteriosus, Patent↗
PubMed1975

Surgical closure of patent ductus arteriosus in the premature infant with respiratory distress.

During the period from February, 1971 to February, 1973, 30 premature infants underwent surgical ligation of patent ductus arteriosus. The gestational ages ranged from 25 to 36 wk (mean 30), and the birth weights ranged from 760 to 2010 g (mean 1274). The patients were divided into two groups on the basis of the indications for assisted ventilation. Group I consisted of 21 patients with severe hylanine membrane disease who required assisted ventilation during the first 2 days of life and could not be weaned off the respiratory by 10 days of age. Group II was composed of nine infants who required intermittent positive-pressure breathing after a mean age of 8 days because of repeated apneic spells secondary to uncontrollable heart failure. All infants in Group II survived the operation and left the hospital well. Fourteen of the 21 patients in Group I survived; the seven deaths were all due to underlying severe pulmonary disease (bronchopulmonary dysplasia). The value of PDA ligation in premature infants with uncontrollable heart failure is demonstrated in this study; this procedure also appears to be beneficial in neonates with severe respiratory distress syndrome.

Aortography↗
PubMed1993

Optimal management of patent ductus arteriosus in the neonate weighing less than 800 g.

Between January 1988 and December 1990, 132 neonates weighing < 800 g were admitted to our neonatal intensive care unit. Of the 76 who survived initial resuscitation, 42 had developed a hemodynamically significant patent ductus arteriosus (PDA) (mean +/- SD): gestational age 25.3 +/- 1.9 weeks, birth weight 650 +/- 93 g. Two infants were referred for primary surgical ligation because of contraindications to indomethacin. Forty infants were initially treated with indomethacin. Seventeen of 40 (43%) were subsequently referred for surgical ligation because of indomethacin failure. Infants requiring surgical duct closure were a lower gestational age (24.6 +/- 1.3 v 25.7 +/- 2.0 weeks, P = 0.49) and had a greater left atrial-aortic (LA/Ao) ratio on echocardiography (1.71 +/- 0.28 v 1.46 +/- 0.26, P = .04) compared with those treated successfully with indomethacin. There were 6 deaths (15%), all of which occurred in infants receiving indomethacin (5 indomethacin alone, 1 indomethacin+ligation). Indomethacin was directly associated with intestinal perforation in 3 patients, and acute renal failure in 1; all 4 died. Surgery was associated with minimal morbidity (intraoperative transfusion in 1, postoperative pneumothorax requiring chest tube in 1). These data suggest that in the extremely premature neonate with a hemodynamically significant PDA: (1) indomethacin therapy is associated with a high failure rate and significant complications; (2) PDA associated with a large LA/Ao ratio is unlikely to close with indomethacin therapy; and (3) surgical duct closure is associated with minimal morbidity. We conclude that primary surgical ligation may provide the optimal management for PDA in carefully selected patients.

Ductus Arteriosus, Patent↗
PubMed1995

Thoracoscopic closure of patent ductus arteriosus: a less traumatic and more cost-effective technique.

The authors have developed a technique of thoracoscopic closure of patent ductus arteriosus (PDA) that significantly reduces the surgical morbidity, recovery time, and hospital costs traditionally associated with the standard open procedure. Ten patients have undergone the procedure, with nine completed successfully. One patient required conversion to an open thoracotomy. There were no operative complications, and closure of the ductus was confirmed in all cases with a postoperative echocardiogram. Eight of ten patients were discharged in under 24 hours, and hospital charges were on the average 30% to 40% less.

Child, Preschool↗
PubMed1986

Patent ductus arteriosus in patients more than 50 years old.

At the Mayo Clinic, from 1945 through 1983, a definitive diagnosis of patent ductus arteriosus was first made in 38 patients when they were more than 50 years old. Of the 29 patients who had cardiac catheterization, 14 had a small left-to-right shunt, 7 had a moderate shunt, and 8 had a large shunt. Five patients, including 2 with right-to-left shunts through the ductus, had pulmonary systolic pressures greater than 75 mm Hg. Thirty procedures were done in 29 patients: ductal ligation in 7, division and suture in 13, transaortic patch closure in 3, and closure via median sternotomy with extracorporeal circulation in 7. There was one intraoperative death (operative mortality, 3.3%). Although technically more challenging, surgical repair is associated with low mortality and excellent follow-up survival. The patients who benefit most from surgical correction are those with Qp/Qs greater than 1.5 and pulmonary artery systolic pressure less than 75 mm Hg.

Aged↗
PubMed1985

Some empirical evidence on post-patent barriers to entry in the Canadian pharmaceutical industry.

In this paper we present some empirical evidence and comment upon the significance of being a pioneering drug in the Canadian pharmaceutical market. We analyse prices and market shares of 21 first entrant drugs in the Canadian pharmaceutical industry. The Canadian experience described in this paper is, we believe, of considerable relevance to U.S. policy makers. Canadian public policy, both federal and provincial, has already created the competitive environment that some U.S. policy makers seek. This paper documents the effect of such a system on the price of drugs and the market shares, hence the revenues, of patent-holders.

Canada↗
PubMed1990

Patents and technology transfer.

Although the discovery and transfer of technology from universities to industry has been taking place for many years, the surge of activity in areas related to biotechnology, over the past fifteen years, has been remarkable. As the very essence of university research requires rapid publication of results, it is particularly important that timely patenting activity take place if an orderly and profitable transfer of technology is to occur.

Biotechnology↗
PubMed1983

Plasma prostaglandin E2 and F2 alpha in preterm infants: association with respiratory distress syndrome and patent ductus arteriosus.

In order to determine if prostaglandin values correlate with gestational age, birth weight, postnatal age, or respiratory distress syndrome (RDS), we determined plasma prostaglandin F2 alpha (PGF2 alpha) and prostaglandin E2 (PGE2) by specific radioimmunoassay in 34 samples from 27 preterm infants. Neither prostaglandin correlated with gestational age or with birth weight. PGF2 alpha decreased (p less than 0.3) with postnatal age. Values for PGF2 alpha and PGE2 in each sample varied together (p less than .01) but only PGF2 alpha increased (p less than .09) in infants with RDS. The highest PGF2 alpha values occurred in infants with severe RDS, including four infants with patent ductus arteriosus (PDA). In contrast, plasma PGE2 was not elevated in infants with RDS or PDA.

Age Factors↗
PubMed1986

Advances in biomedical sensor technology: a review of the 1985 patent literature.

The 1985 patent literature pertaining to biomedical sensor technology is reviewed and an assessment made of the types of devices that are most likely to reach commercialisation. Novel systems that are described comprise electrochemical, optical, thermal and other transducers for monitoring key components of clinical samples. These include blood gases and electrolytes, metabolites, enzymes, proteins, antibodies and antigens.

Biotechnology↗
PubMed1985

Incidence and risk factors for symptomatic patent ductus arteriosus among inborn very-low-birth-weight infants.

The incidence of symptomatic patent ductus arteriosus (sPDA) in very-low-birth-weight infants has been reported almost exclusively from referral centers. Moreover, the incidence has varied considerably. We prospectively evaluated the incidence and risk factors of sPDA in a totally inborn population of infants less than or equal to 1500 g birth weight (n = 120) receiving conservative fluid management and examined the role of echocardiography in predicting sPDA before clinical signs are evident. The incidence of sPDA was relatively low (16%) and the age at onset was relatively late (mean +/- S.E. = 14.7 +/- 3.0 days) when compared to prior reports. Echocardiographic changes preceded physical and radiographic findings of sPDA. Fluid volume within the range administered to our infants was unrelated to the occurrence of sPDA. However, risk factors identifiable within 24 h of birth were defined: obstetric estimate of gestational age, race, mean fluid volume intake in the initial 24 h, and early treatment with volume expanders. From these risk factors, 79% of infants with sPDA and 79% without sPDA could be predicted by stepwise discriminant function analyses. These findings may be employed in studies needed to assess the benefit of early surgical or pharmacologic therapy for infants at highest risk for sPDA.

Delivery, Obstetric↗
PubMed1991

Symptomatic patent ductus arteriosus in very-low-birth-weight infants: 1987-1989.

Symptomatic patent ductus arteriosus (sPDA) may occur in up to 50% of very-low-birth-weight (VLBW, less than or equal to 1500 g) infants. We reported a 16% incidence in 1979-1980 in a totally inborn population, demonstrating the importance of early fluid management. Although survival of VLBW infants, especially those less than 1000 g, has increased, sPDA has not been carefully re-examined. Therefore, we sought to determine if the incidence, morbidity, treatment, or risk factors for sPDA had changed in this population. Between January 1, 1987 and December 31, 1989 all VLBW infants with sPDA surviving greater than 72 h (119/636) were identified and compared to matched controls (n = 70). Incidence and onset of sPDA were 19% and 10 +/- 6 days (+/- S.D.), respectively, the former increasing from 8% to 33% between 1251-1500 g and 500-750 g, respectively (P less than 0.001). Fluid and colloid administration were similar in sPDA and control infants. sPDA was associated with the occurrence of chronic lung disease (18% vs 7%, P = 0.005) and intracranial hemorrhage (53% vs 21%, P less than 0.001). Using stepwise logistic regression analysis we were unable to create a model that accurately predicted sPDA. Medical management and indomethacin were unsuccessful in 66% and 25%, respectively, of infants so treated; 43% required surgical ligation. Although survival of VLBW infants has increased, our incidence of sPDA remains low, with greater than 80% of infants demonstrating spontaneous closure when fluid and colloid administration are judiciously used.

Analysis of Variance↗
PubMed1988

Doppler echocardiographic flow characteristics of isolated patent ductus arteriosus: better delineation by Doppler color flow mapping.

Eighteen infants and children with isolated ductus arteriosus and various hemodynamic states were examined with the Doppler color flow mapping technique to study the flow patterns of the patent ductus and its adjacent structures. Direct visualization of the ductus was achieved in all patients. All ductal flow was shunting left to right from the descending aorta to the pulmonary artery even in the presence of significant elevation of pulmonary artery pressure. However, transient bidirectional shunting was observed in two patients on serial studies. Disturbed systolic and diastolic flows were demonstrated within the ductus in each case. The blood flows in the main pulmonary artery consisted of three distinguishable areas: 1) a characteristic high velocity turbulent retrograde ductal jet throughout the entire cardiac cycle, located in the anterolateral aspect of the main pulmonary artery; 2) nonspecific low velocity retrograde late systolic and early diastolic flow, located in the posteromedial aspect of the main pulmonary artery; and 3) low velocity forward systolic and diastolic flow, occupying the remaining area of the pulmonary artery. The blood flows in the descending aorta near the ductal orifice consisted of disturbed systolic and diastolic flows in a reversed direction. By providing detailed real time blood flow information with simultaneous imaging of the ductus, Doppler color flow mapping greatly facilitates the detection of a small ductal shunt. This technique also allows detection of a bidirectional or right to left ductal shunt.

Aorta↗
PubMed1994

Imaged thoracoscopic surgery--patent ductus arteriosus ligation.

Video-assisted thoracic surgery (VATS) combines excellent visualization of the intrathoracic structures with a minimally invasive technique. A patient is presented who underwent successful ligation of a patent ductus arteriosus with a video-assisted thoracoscopic technique.

Adult↗