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Biomedical subjects

L L Bailey

Publications and source records attributed to L L Bailey.

At least 91 records · Page 5Linked to original sources
PubMed1992

Successful transplantation of hearts harvested 30 minutes after death from exsanguination.

The donor pool for heart transplants is severely limited. Unfortunately, many trauma patients who might be donors die of exsanguination before their organs can be used. We tested whether hearts "dead" for one half hour after exsanguination could be used as heart transplants in 8 lambs (mean weight, 8 kg). Four lambs were exsanguinated by severing the subclavian artery while simultaneously infusing intravenous saline solution to mimic resuscitation attempts. All animals died. Thirty minutes after hypotensive arrest and death, simulating the time needed to secure donation permission, the heart was harvested, perfused with 250 mL of cold cardioplegia containing 200,000 units of streptokinase to dissolve intravascular clots, and stored in iced saline solution for a mean of 1.5 hours while 4 recipient lambs were prepared for operation. After bypass and recipient heart excision, the "dead" donor heart was transplanted orthotopically. The heart was reperfused with low flow (25 mL/min), low pressure (30 mm Hg), low hematocrit (hematocrit, 0.08 to 0.12) blood supplemented with prostaglandin E1 and nifedipine for 15 minutes, followed by full flow rewarming for 45 minutes. All hearts resumed normal contractions. All animals were weaned from bypass without inotropes. Pressures a half hour after bypass were (in mm Hg): aorta, 80 +/- 10; pulmonary artery, 20 +/- 5; right atrium, 9 +/- 5; and left atrium, 9 +/- 2. We conclude that hearts "dead" for one half hour after exsanguination are capable of being reanimated and used successfully as donor organs. With further development, this method could potentially greatly expand the donor heart pool.

Animals↗
PubMed1992

The Mustard procedure for correction of simple transposition of the great arteries before 1 month of age.

Since April 1976, 34 infants (25 male and 9 female) less than 1 month of age underwent a Mustard intraatrial baffle procedure for repair of simple transposition of the great arteries. Thirty patients were less than 2 weeks old and 19 patients less than 1 week (mean 7.8 +/- 6 days). The weights ranged from 2.6 to 4.4 kg (mean 3.4 +/- 0.4 kg). Rashkind balloon atrial septostomy was performed in the first hours or days of life in 29 patients. The average interval from balloon atrial septostomy to baffle repair was 3.9 days (range 2 hours to 14 days). Mechanical ventilation was required in eight patients preoperatively and prostaglandin E1 was infused in 17 patients to maintain ductal patency. In all patients, the Mustard procedure was performed with the use of deep hypothermic circulatory arrest, averaging 53 minutes (range 37 to 82 minutes). The duration of postoperative intubation and ventilatory support averaged 1.7 +/- 1.0 days (range 1 to 5 days). Inotropic drugs were used in 24 patients during a period of 1.4 +/- 1.3 days (range 1 to 6 days) postoperatively. There were no hospital deaths. Follow-up evaluation has extended from 1 month to 14 years (mean 3 +/- 3 years). One infant died 2 months postoperatively as a result of milk aspiration; no cardiac defects were found at the autopsy. A second infant died at 1 year with right ventricular and tricuspid valve dysfunction. Baffle complications occurred in 6 of the 32 survivors, including superior vena caval stenosis in 4, inferior vena caval stenosis in 1, and pulmonary venous obstruction in 3. Reoperations for baffle obstructions were performed in three patients (8.8%) and balloon angioplasties in two. One patient required permanent pacemaker implantation. Results with the Mustard procedure before 1 month of age show that it can be performed with negligible mortality and a low incidence of late complications at an age comparable to when arterial switching would be performed. Until long-term studies demonstrate superiority of arterial operations, the low operative mortality favors continued evaluation of the neonatal Mustard repair as a valid alternative to the arterial switch.

Cardiac Surgical Procedures↗
PubMed1992

The effects of donor-recipient size disparity in infant and pediatric heart transplantation.

To determine the effect of heart donor and recipient size mismatches in infant and pediatric heart transplantation, we studied all 69 patients (age 1 day to 11 years) having 71 orthotopic heart transplants from 1985 to 1989. Patients were divided into three groups based on donor to recipient weight ratios. Group I comprised 13 heart transplants with a donor to recipient weight ratio less than 0.95 (mean 0.81, range 0.48 to 0.94); group II comprised 29 heart transplants with a weight ratio between 0.95 and 1.60 (mean 1.28); and group III had 27 heart transplants with weight ratios greater than 1.60 (mean 2.2, range 1.61 to 3.09). All chests were closed primarily. The cardiothoracic ratio by chest radiography was significantly larger in group III (p = 0.0002); 75% of group III patients had periods of lobar or complete lung collapse by chest radiography compared with 28% of group II and 19% of group I patients (p < 0.05). Despite this, there was no difference in the number of days of ventilator support for any group (p = 0.92). There was no difference in graft ischemic time or inotropic drug use among groups, nor were differences found in the cardiac systolic function parameters of left ventricular preejection time (p = 0.975), left ventricular ejection time (p = 0.975), left ventricular fiber shortening (p = 0.97), and left ventricular fractional shortening (p = 0.596). Thus despite a high incidence of transient lobar or complete lung collapse in high donor to recipient weight ratio transplants, large donor heart size produces very little clinical impairment in recipient lung function. Size mismatches do not influence cardiac systolic function. Overall, large size mismatches appear to be very well tolerated in infant and pediatric heart transplantation.

Body Weight↗
PubMed1992

Optimal delivery of cardioplegic solution for "redo" operations.

Increasing experience suggests that retrograde cardioplegia offers several benefits during cardiac reoperations. However, the need for dissection to allow caval snares for open coronary sinus intubation or to palpate the atrioventricular groove for transatrial coronary sinus intubation may disturb diseased vein grafts or require more dissection than necessary. Although antegrade-retrograde techniques can be used, antegrade cardioplegia risks atheromatous embolization from old vein grafts. To optimize delivery of cardioplegic solution, we designed and used "no touch" transatrial intubation of the coronary sinus for retrograde delivery of cardioplegic solution in 63 consecutive patients aged 20 to 87 years (mean 68 years) undergoing 36 redo coronary bypass operations, 7 combined redo coronary bypass/valve replacements, 6 redo aortic valve repairs/replacements, 6 redo mitral valve repairs/replacements, 4 redo double valve repairs/replacements, 2 redo triple valve repairs/replacements, and 2 redo composite aortic valve and arch replacements. "No touch" coronary sinus cannulation was achieved by minimally dissecting the aorta and high right atrium enough for two purse-string sutures. No attempt was made to dissect the junction of the inferior vena cava and atrioventricular groove if old vein grafts were present. The distal pressure line of the Gundry DLP RCSP retrograde cardioplegia cannula (DPL, Inc., Grand Rapids, Mich.) was connected to a transducer, flushed, and then introduced into the right atrium. The pressure tracing thus obtained was observed while the catheter was advanced, using its curved stylet, "blindly" without touching the heart, through the right atrium into the coronary sinus until a coronary sinus waveform was obtained (similar to floating a thermodilution catheter). The catheter's distal balloon was then inflated to occlude the coronary sinus momentarily. A rise in sinus pressure confirmed placement. If pressure did not rise, the cannula was usually in the right ventricle and was repositioned. All coronary sinuses were successfully intubated blindly. Bypass was then instituted, the aorta crossclamped, and the proximal aorta vented. Old vein grafts were cut at the aorta before retrograde cardioplegia was begun; atheromatous material was routinely flushed retrogradely from vein grafts. Only after arrest were hearts dissected as needed. Antegrade cardioplegia was not used. There were two (3%) deaths, both from hospital-acquired pneumonia, no perioperative myocardial infarctions, and no episodes of heart block. Inotropic agents were used in six of 63 patients (10%). We conclude that "no touch" transatrial retrograde cardioplegia offers optimal, simplified myocardial protection for cardiac reoperations, permits arrest of the heart before cardiac manipulations, and expands the use of retrograde cardioplegia by obviating cardiac dissection.

Aged↗
PubMed1991

Modification of the pulmonary connective tissue developmental response in the neonatal rat by ciclosporin.

Neonatal rat pups were treated either with ciclosporin at 10 mg/kg/day dissolved in olive oil (experimental) or with pure olive oil (control). Lung protein biosynthesis was evaluated in a protocol which involved the measurement of total accumulated protein, collagen and elastin. Four time points were studied in the first 21 days of life, 12 animals contributing to each point (6 control and 6 ciclosporin). Ciclosporin levels in the treated group ranged widely (2,000-4,000 ng/ml). There were significant differences in total body weight and lung weight in treated vs. controls during and after the first week. DNA contents per unit wet weight varied significantly during the second week of life, indicating increased cellularity of the ciclosporin-treated animals. Associated with this was an increase in the lung protein/DNA ratio as well as the elastin/DNA ratio in the control animals, but not in the treated ones. The lung collagen/DNA ratio was not as dramatically affected by the ciclosporin treatment. However, the collagen content per unit wet weight of lung tissue was increased in the ciclosporin-treated animals at 15 days of life. We conclude that ciclosporin has a marked effect on lung connective tissue metabolism in early life, the long-term effects of which are unappreciated and undocumented but may well be of vital importance in the lungs of long-surviving organ transplant patients.

Animals↗
PubMed1991

Infant heart transplantation 1991.

Between November 1985 and June 1991, there were 118 orthotopic heart transplantations performed on 117 infants less than 1 year old. Indications for transplantation were dominated by complex congenital heart disease (92%). Weight ratio between donor and recipient was 1.75 +/- 0.72 and ischemic time was 255 +/- 121 minutes. Early mortality was 10.2% and 5-year actuarial survival was 79%. Rejection diagnoses have been achieved mainly with noninvasive techniques. The immunosuppression regimen was comprised of daily cyclosporine A and azathioprine. Steroids were used only for rejection treatment. These results are encouraging and comparable to those of adult transplantation. The shortage of organ donors remains a major problem in pediatric transplantation.

Actuarial Analysis↗
PubMed1991

[Selection and management of donor hearts in infant and pediatric heart transplantation: Loma Linda experience].

One hundred and six infant and pediatric patients received 108 heart transplantations between November 1985 and December 1990. The age of the recipients was from 0 day to 12 years (mean 11.1 months) and the age of the donors were from 2 days to 24 years (mean 18.3 months). The body weight ratio of donor and recipient were from 59% to 315% (mean 163%). Large donor hearts were well tolerated without serious complication even in small infants. The graft ischemic time was from 51 minutes to 505 minutes (mean 244 minutes) and fifty four grafts had ischemic time more than 4 hours. There was no difference of the frequency of primary graft failure between the grafts with longer and shorter ischemic time. Although diastolic function in the first week post-transplant was more depressed in the grafts with longer ischemic time, no difference was observed after the second post-transplant week. There was no difference in the systolic function in accordance with the ischemic time. Eight hours and more ischemic time was well tolerated in our donor grafts.

Adolescent↗
PubMed1991

[Infant and pediatric heart transplantation: Loma Linda experience].

One hundred and six infant and pediatric recipients underwent 108 heart transplantation from November 1985 to December 1990 in Loma Linda University Medical Center. Forty-seven recipients were under one month of age at the time of transplantation, 46 from one month to 2 years and 15 over two years. Seventy recipients underwent heart transplantation under the diagnosis of hypoplastic left heart syndrome or the diseases equal to hypoplastic left heart syndrome, seventeen for complex congenital heart disease, sixteen for cardiomyopathy, and five for other reasons. Early mortality was 13% and late mortality was 11% for all cases. Early mortality for the infants under one month of age was 13% and late mortality was 8%. Heart transplantation was considered to be the treatment for choice for the patient with otherwise fatal cardiac diseases.

Age Factors↗
PubMed1990

Facile retrograde cardioplegia: transatrial cannulation of the coronary sinus.

The benefits of coronary sinus (CS) cardioplegia are well known, yet CS cardioplegia is not used widely owing to the need for bicaval cannulation, snares, and an atriotomy. We designed and used in 225 consecutive patients a catheter containing a flexible removable stylet that, when shaped into a hockey-stick configuration, enabled blind intubation of the CS through a small pursestring in the right atrium, guided easily into the CS using a finger on the atrioventricular groove at the inferior vena cava. The CS was intubated in all patients; a pressure-limited balloon at the catheter tip was inflated after cross-clamping. An integral distal pressure line measured CS pressure. Catheters were placed distally within the great cardiac vein beyond the posterior interventricular vein; the position did not alter cooling: right ventricular free wall, septum, and left ventricular free wall temperatures were 7 degrees +/- 2 degrees, 8 degrees +/- 2 degrees, and 7 degrees +/- 2 degrees C, respectively, after an initial 10 mL/kg of blood cardioplegia. Transatrial CS cardioplegia was used in 45 aortic valve replacements, 22 mitral valve replacements, 4 triple-valve replacements, 6 congenital lesions, and 148 coronary revascularizations, including 40 redo operations. Atheromatous material was routinely flushed retrogradely from cut old vein grafts during revascularization; 70 revascularizations (47%) were performed urgently for acute infarction or jeopardized myocardium. No heart block or CS injury occurred, and inotrope use dropped to 10% of patients (from 38% in the previous 256 patients with antegrade blood cardioplegia). We conclude that the CS can be cannulated transatrially and that CS cardioplegia is more facile than antegrade cardioplegia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Cardiac transplantation in infancy: donors and recipients. Loma Linda University Pediatric Heart Transplant Group.

To evaluate the role of orthotopic cardiac transplantation for infants with lethal cardiac disease, we reviewed the results from our first 25 patients. Data on the donors were also reviewed to define the characteristics of a successful cardiac donor. Patients had transplants between November 1985 and November 1988. Several primary cardiac diagnoses were indications for transplantation, including congestive cardiomyopathy, hypoplastic left-heart syndrome, and other types of native and postoperative complex congenital heart diseases. The ages ranged from birth to 7 months. Of 25 patients, 21 are still alive (84% survival rate) with follow-up from 4 to 40 months. No late deaths have occurred. Long-term immunosuppression was accomplished with cyclosporine and azathioprine. Rejection surveillance was performed noninvasively; only one child required an endomyocardial biopsy. Donors died from a variety of traumatic and metabolic causes, including sudden infant death syndrome. The majority (72%) of donors had a history of cardiac arrest requiring cardiopulmonary resuscitation. One third were receiving inotropic support at the time of cardiac evaluation. We conclude that orthotopic cardiac transplantation is an effective therapy for infants with lethal heart disease. A larger donor pool is required, and many dying infants, despite cardiac arrest and resuscitation, would be suitable donors.

Female↗
PubMed1990

Hypoplastic left heart syndrome.

HLHS is a complex developmental malformation of the left ventricle, aorta, and associated valves. Survival beyond neonatal life is the exception in untreated infants. The prognosis, however, is no longer hopeless. Newer surgical strategies of staged palliative reconstruction and heart replacement by transplantation appear promising. These options on occasion will become complementary in the management of individual patients. Those children surviving Fontan operations are frequently able to lead NYHA Class I or II lives without drugs, while transplant recipients will require one or more immunoregulative medications indefinitely. Exercise tolerance and work capacity following the Fontan procedure are reported to be 40 to 60 per cent of expected normals. Full functional capacity of successfully palliated children may never be normal. In contrast, exercise capability after heart transplantation is generally better than that following a Fontan operation, with cardiac ejection fractions approaching normal for age. Durability of these new management technologies will make inappropriate the traditional "do nothing" approach to HLHS in all but a few cases.

Decision Trees↗
PubMed1990

Another look at cardiac xenotransplantation.

Clinical incentive for development of neonatal cardiac xenotransplantation is clear. Approximately 10% of babies born with congenital heart disease might benefit from transplantation therapy, but human donor resources in this age group are limited. A scientific foundation upon which to base clinical trials of neonatal cardiac xenotransplantation is presented. A single clinical case and its outcome is reviewed. What was learned from this case supports continued clinical trials in the form of xenograft "bridging" to allotransplantation. There are perhaps three potential impediments to progress in xenotransplantation. These restrictions may be broadly categorized as: (1) immunological; (2) philosophical; and (3) sociological. None of these potential "barriers" is absolute and incentive is strong to continue exploration of neonatal cardiac xenotransplantation.

Animals↗