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Biomedical subjects

D J Murphy

Publications and source records attributed to D J Murphy.

At least 163 records · Page 9Linked to original sources
PubMed1988

Senning repair for transposition of the great arteries without patch augmentation of the septum.

Forty-three consecutive patients with previous balloon atrial septostomy have undergone a Senning type repair of transposition of the great arteries without patch augmentation of the atrial septum. A technique was used that allows expansion of the atrial septum without the use of additional foreign or autogenous materials. The operative (30-day) mortality rate was 4.6% (2/43) with no late deaths. A mean follow-up of 20 months shows that 83% of the patients are in sinus rhythm and none of these patients have clinically detectable caval or pulmonary venous obstruction or baffle leaks. In patients selected for atrial switch, the Senning operation may be performed without patch augmentation of the septum. Performed by the method described herein, the operation provides predictable early and late results with a low prevalence of arrhythmias. Significant venous obstruction has not occurred.

Female↗
PubMed1987

Response of the patent ductus arteriosus to indomethacin treatment.

The purposes of this study were to examine the response of the patent ductus arteriosus (PDA) to indomethacin, using serial two-dimensional and pulsed Doppler echocardiographic studies, and to correlate the response to treatment with serum indomethacin levels. Nineteen preterm infants (gestational age, 26 to 31 weeks [mean, 28 weeks]; weight, 600 to 1680 g [mean, 1060 g]) were treated with indomethacin. Two-dimensional and pulsed Doppler echocardiograms were obtained before administration of indomethacin and daily thereafter until the day after the last dose. Ductal responses to treatment were graded as open, constricted, or closed, and serum indomethacin levels were obtained 24 hours after the last dose. The PDA initially closed in 11 (58%) of 19 infants; however, in four of the 11, PDA reopened and three of four required surgical ligation. In seven (37%) of 19 patients, the PDA initially constricted, but five of seven subsequently reopened and required ligation. In one patient, indomethacin had no effect on the PDA. The mean indomethacin level for the whole group was 622 ng/mL. There was no difference in indomethacin level between the group with initial closure vs those with constriction (580 vs 590 ng/mL), nor between those who eventually required ligation and those who did not. This study demonstrates that the majority of premature infants respond to indomethacin treatment with ductal constriction or closure but that reopening occurs frequently. The initial response does not mean that the ductus will remain constricted or closed, and surgical intervention may still be necessary. A serum indomethacin level of more than 250 ng/mL does not ensure ductal closure.

Drug Evaluation↗
PubMed1987

Massive upper gastrointestinal hemorrhage in an infant following cardiac surgery.

This is a case of massive upper gastrointestinal hemorrhage and hematoma formation in a 32-day-old infant following uneventful repair of congenital heart disease. Stress ulcers and gastrointestinal hemorrhage are rare complications of cardiac surgery in the young. Conservative management often fails and early surgery can be lifesaving. The etiology of this problem remains unknown and more work is needed so that effective preventive measures can be developed.

Gastrointestinal Hemorrhage↗
PubMed1987

A biomechanical study of distal radial fractures.

In an attempt to explain disability in dorsally angulated malunited distal radius fractures, an experiment was designed to evaluate load patterns about the wrist with varying degrees of dorsal angulation of the distal radius. Osteotomies were made in the distal radius of fresh cadaver arms after a modified external fixator was applied to the radius and load cells applied to the proximal radius and ulna. Pressure-sensitive film was inserted into the radioulnar carpal joint. After a predetermined load was applied to the wrist it was found that the load through the ulna increased from 21% to 67% of the total load as the angulation of the distal radial fragment increased from 10 degrees of palmar tilt to 45 degrees of dorsal tilt. The pressure distribution on the ulnar and radial articular surfaces changed in position and became more concentrated as dorsal angulation increased.

Biomechanical Phenomena↗
PubMed1987

Pulmonary venous and systemic ventricular inflow obstruction in patients with congenital heart disease: detection by combined two-dimensional and Doppler echocardiography.

Obstruction to pulmonary venous return may be associated with a number of congenital cardiovascular abnormalities occurring both before and after surgery. Hemodynamic assessment by cardiac catheterization is often difficult. A noninvasive method for detection and quantitation of obstruction to systemic ventricular inflow would be clinically useful. Two-dimensionally directed pulsed and continuous wave Doppler echocardiography was performed before cardiac catheterization in 31 patients thought clinically to have possible obstruction to left ventricular inflow or pulmonary venous return. Primary diagnoses included transposition of the great arteries after the Mustard or Senning procedure in nine patients, total anomalous pulmonary venous connection in nine (in two after surgical repair), cor triatriatum in eight (in four after surgical repair), congenital mitral stenosis in four (in one after surgical repair) and mitral atresia in one. Severe obstruction was defined as a mean pressure gradient at catheterization of greater than or equal to 16 mm Hg at any level of the pulmonary venous return or of the systemic ventricular inflow. Severe obstruction was predicted if Doppler examination measured a flow velocity of greater than or equal to 2 m/s across any area of inflow obstruction. At catheterization, 12 patients (39%) had severe obstruction to left ventricular inflow or pulmonary venous return and all obstructions were correctly detected by Doppler echocardiography. The site of pulmonary venous obstruction was localized by two-dimensionally directed pulsed Doppler study. Patients with a lesser degree of obstruction had a lower Doppler velocity, but none had a maximal Doppler velocity of greater than or equal to 2 ms/s.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Surgery without catheterization for congenital heart defects: management of 100 patients.

Little information is available regarding the surgical mortality of children with congenital heart disease who undergo operation on the basis of clinical assessment and echocardiographic diagnosis without cardiac catheterization. If catheterization affects early surgical mortality then perhaps omitting it would improve survival. Early operative mortality of 100 patients managed with echocardiography without preoperative catheterization (Group I) was compared with that of 151 diagnosis-matched control patients who had catheterization (Group II). The catheterization (Group II) and echocardiographic (Group I) groups included patients with the following diagnoses: atrial septal defect (33 and 17 in Group II and Group I, respectively); pulmonary stenosis/pulmonary atresia (33 and 15), aortic stenosis (14 and 3), coarctation of aorta (36 and 29), patent ductus arteriosus (10 and 15) and miscellaneous (25 and 21). Age range was 1 day to 16 years (mean 3.5); 114 (45%) of the 251 patients were less than 1 year of age and 59 (29%) were less than 1 month of age. With one exception, echocardiographic diagnosis was correct when compared with findings at surgery or autopsy, or both. Surgical mortality was 18% in Group I and 9% in Group II; however, multiple logistic regression analysis adjusting for differences in age and preoperative condition showed no significant difference between the two groups with a trend toward lower mortality in Group I (p = 0.075). Echocardiography as the definitive imaging modality in selected patients with congenital heart disease is accurate and is comparable with conventional methods of preoperative diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Small bowel obstruction as a complication of Kawasaki disease.

A case of small bowel obstruction in an 8-month-old infant with Kawasaki disease is described. At laparotomy a discrete area of jejunal stricture with adhesions was noted. Microscopic examination revealed evidence of small artery thrombosis. Kawasaki disease results in a diffuse vasculitis, which may produce significant abnormalities in multiple organ systems. Serious abdominal complications can occur and should be considered when gastrointestinal symptoms develop in a patient with Kawasaki disease.

Humans↗
PubMed1987

Ultrasound examination of extracardiac chest masses in children. Doppler diagnosis of a vascular etiology.

The purpose of this paper is to describe the use of two-dimensional and Doppler ultrasound techniques in the evaluation of chest masses of unknown etiology. We reviewed the diagnosis of chest masses in 12 children seen over 3 years, all confirmed by surgery or pathology. The masses were vascular in three patients (pseudoaneurysm) and nonvascular in nine. Ultrasound yielded a correct differential diagnosis of the masses. Doppler sampling diagnosed the vascular etiology of the three pseudoaneurysms. We conclude that Doppler techniques can identify the vascular nature of chest masses, and that ultrasonography is valuable in the assessment of chest masses in children.

Child↗
PubMed1986

Axonal regeneration in spinal cord injury: a perspective and new technique.

A set of techniques is described for determining the response of mammalian spinal axons to transection. The logical selection and the advantages of these techniques are discussed. The dorsal column of guinea pig thoracic spinal cord was transected with a tungsten needle and the position of the lesion was marked by a staple-shaped wire device (Foerster: J. Comp. Neurol. 210:335-356, '82). The morphology of dorsal column axons projecting rostrally toward the lesion was examined between 1 and 50 days postlesion by anterograde staining with horseradish peroxidase, applied to a second lesion of the dorsal column two to three vertebral segments caudal to the first. Axons damaged by the original lesion were found to die back 1-2 mm from the plane of transection and at 18-20 hours were characterized by terminal club-shaped swellings attached to the proximal axon by a thin connection. At 50 days postlesion there was some evidence of limited regenerative responses in terms of growth-cone-like axon terminals, and the presence of aberrant axonal branching, but no evidence of regenerating axons approaching close to the plane of transection. These findings are in agreement with previous studies indicating little or no effective regrowth of myelinated axons in the mammalian spinal cord. These same techniques were used in a succeeding study to examine the effects of applied electric fields on the axonal response to transection.

Animals↗
PubMed1986

Transected dorsal column axons within the guinea pig spinal cord regenerate in the presence of an applied electric field.

Using an implanted battery and electrodes, we have imposed a weak, steady electrical field across partially severed guinea pig spinal cords. We have analyzed regeneration of dorsal column axons in experimental animals and sham-treated controls at 50-60 days postinjury by anterograde filling of these axons with the intracellular marker horseradish peroxidase and by employing a marking device to identify precisely the original plane of transection (J. Comp. Neurol. 250: 157-167, '86). In response to electric field applications, axons grew into the glial scar, as far as the plane of transection in most experimental animals. In a few animals axons could be traced around the margins of the lesion (but never through it). Moreover, these fibers returned to their approximate positions within the rostral spinal cord before turning toward the brain. In sham-treated controls, ascending axons were found to terminate caudal to the glial scar, and rarely were any fibers found within the scar itself. Axons were never observed to cross into the rostral cord segment. These findings suggest that an imposed electrical field promotes growth of axons within the partially severed mammalian spinal cord, that a steady voltage gradient may be an environmental component necessary for axonal development and regeneration, and that some component(s) of the scar impede or deflect axonal growth and projection.

Animals↗
PubMed1986

Continuous-wave Doppler in children with ventricular septal defect: noninvasive estimation of interventricular pressure gradient.

Continuous-wave Doppler was used to estimate the pressure gradient between the right and left ventricles in 28 children with ventricular septal defect (VSD). Doppler measurement of maximal velocity was performed during cardiac catheterization and the Doppler-predicted gradient was compared with the peak-to-peak gradient measured simultaneously by catheter. Doppler gradients ranged from 10 to 71 mm Hg and correlated well with measured gradient (r = 0.97, p greater than or equal to 0.001). Fourteen patients had isolated VSD, and in these patients Doppler measurements of gradient allowed accurate estimation of right ventricular pressure (r = 0.93). There was an inverse correlation between the ratio of pulmonary to systemic resistance and maximal velocity (r = -0.77). Thus, continuous-wave Doppler is an accurate means of measuring instantaneous VSD pressure gradient in children with congenital heart disease and can be used to estimate the right ventricular and pulmonary artery pressure in children with isolated VSD. This noninvasive method can be used to distinguish restrictive from nonrestrictive VSD.

Adolescent↗
PubMed1986

Left ventricular function in normal newborn infants and asymptomatic infants with neonatal polycythemia.

Digitized M-mode echocardiography was used to evaluate left ventricular (LV) function in normal neonates and to document subtle abnormalities of LV function in 19 asymptomatic newborn infants with polycythemia and hyperviscosity. Echocardiograms were performed before and after partial exchange transfusion and at 48 hours of age. Results were compared to those obtained from analysis of echocardiograms from 18 normal infants with normal hematocrits at 12 and 48 hours of age. In the normal group there were no differences between the digitized indices of LV function at 12 hours and those at 48 hours of age. In the polycythemic group, prior to hemodilution, the peak rate of LV emptying was low compared to normal values (-3.1 +/- 0.7 sec-1 vs -3.6 +/- 1.0 sec-1, p less than 0.05) and normalized following the procedure to -3.7 +/- 1.3 sec-1. The peak rate of left ventricular posterior wall (LVPW) thickening also increased following partial exchange transfusion (3.2 +/- 0.6 sec-1 to 3.7 +/- 1.0 sec-1, p less than 0.05). At 48 hours of age peak rates of change for the left ventricle (-2.9 +/- 0.8) and LVPW (3.0 +/- 0.7) were abnormally low in the polycythemic infants, all of whom had undergone partial exchange transfusion. Also, at 48 hours, the LVPW time to peak rate of thickening and time to the end of thickening were prolonged. In addition, the peak rate of LV filling in diastole was low in the polycythemic group (3.0 +/- 0.9 sec-1 vs 3.9 +/- 1.3 sec-1, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Viscosity↗
PubMed1986

A 192Ir nomogram system for single plane implants.

Nomograms for square planar arrays spanning the range from 3 X 3 cm to 10 X 10 cm were developed. The nomograms are intended to be used for pretreatment planning of implant geometry, so that the therapist may enter the operating room with a plan for the optimal implant in mind. We show that clinically useful implants are those in which the reference isodoses are fully coupled. Decoupling occurs when ribbon spacing exceeds approximately 1.2 cm and leads to undesirable "cold spots" within the treatment volume. Ribbon spacing of 1.0 cm is recommended. This represents a trade-off between adequate ribbon coupling and minimum tissue damage from trocar placement. For clinically useful arrays, the area enclosed by the reference isodose contour (85% of the maximum dose rate) is approximately 50% of the array area. Reference isodose contour and its enclosed area are independent of seed strength for a given array, as long as all seeds within the array are of equal strength.

Brachytherapy↗
PubMed1986

Biomechanical analysis of internal fixation techniques for proximal interphalangeal joint arthrodesis.

Although numerous fixation techniques have been developed for performing small joint arthrodesis, no previous study of the biomechanical properties of these constructs has been published. The strength of specimens of arthrodesis of the proximal interphalangeal joint performed with cadaver material was determined for three-point anteroposterior bending, axial torsion, and lateral cantilever bending stress. Crossed Kirschner wires, intraosseous wiring, and figure of eight tension-band wiring were studied. Figure of eight tension-band wiring demonstrates superior strength in anteroposterior bending and torsion. For lateral bending stress, no significant difference exists among the techniques studied.

Arthrodesis↗
PubMed1986

Quantitative morphology of the aortic arch in neonatal coarctation.

It has been speculated that neonatal coarctation results from postnatal constriction of the aortic isthmus and ductus arteriosus. However, aortic arch hypoplasia is present in some neonates with coarctation and is presumed to be due to decreased aortic arch blood flow in utero. To measure the degree of aortic arch hypoplasia and to analyze the distribution of blood flow in neonatal coarctation, quantitative morphometric analysis of the great vessels from two-dimensional echocardiograms was performed in 14 neonates with isolated coarctation and 14 normal control neonates, all less than 1 month old. Measurements of the aortic valve, pulmonary valve, ascending aorta, transverse aortic arch between the carotid and subclavian arteries, aortic isthmus, descending aorta, main pulmonary artery and brachiocephalic vessels were obtained to the nearest 0.5 mm. In coarctation patients the transverse arch and isthmus were significantly smaller than in control subjects (p less than 0.001). In addition, pulmonary valve and main pulmonary artery diameters were significantly greater in neonates with coarctation than in normal neonates. Transverse arch hypoplasia and increased pulmonary valve and pulmonary artery diameters are present in neonates with coarctation. This suggests decreased aortic arch flow and increased pulmonary and ductus arteriosus flow in utero, which produce a characteristic echocardiographic appearance of transverse arch hypoplasia with a large main pulmonary artery.

Aorta, Thoracic↗