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Biomedical subjects

L L Bailey

Publications and source records attributed to L L Bailey.

At least 55 records · Page 3Linked to original sources
PubMed1997

Is there a safe limit to coronary sinus pressure during retrograde cardioplegia?

Although retrograde cardioplegia (RC) delivered via the coronary sinus (CS) is now used routinely, the pressure at which RC can be safely delivered is thought to be 50 to 60 mm Hg. Such practice is based on experiments performed on working, beating hearts with CS ligation and arterial inflow into both the coronary arteries and veins (Beck procedure). However, no data exist on arrested, vented hearts, as occurs clinically during RC. We studied the acute effect of 10 cc/kg of blood RC delivered into the CSs of 16 adult vented pig hearts, which were randomly assigned to four groups of four hearts each according to the CS pressure maintained during perfusion: 40, 80, 100, and 120 mm Hg. After RC, hearts were excised, cut in bread-loaf sections, examined grossly, and then fixed and stained. Sections of right ventricle, septum, and left ventricle were then examined by two blinded cardiac pathologists and two blinded surgeons and scored for the presence of extravascular hemorrhage. None of the 16 hearts tested showed any evidence of gross or microscopic hemorrhage; all hearts showed normal myocardial preservations and structure, including all hearts at 100 and 120 mm Hg CS perfusion pressure. We conclude that CS pressures up to 120 mm Hg cause no extravasation of blood into the myocardium in the vented, arrested heart. These results contradict studies on the working, beating heart, and suggest that high pressures in the CS are well tolerated during RC.

Animals↗
PubMed1996

Uniformity of perfusion in all regions of the human heart by warm continuous retrograde cardioplegia.

BACKGROUND: Animal models have suggested that retrograde cardioplegia may be poorly distributed to septal and right ventricular regions of the heart; if true, this may have dangerous implications for warm continuous retrograde cardioplegia in humans. We have previously shown that blood gases from coronary arteries during warm continuous retrograde cardioplegia represent postcapillary "venous" gases and are reflective of myocardial perfusion. METHODS: To determine regional differences in perfusion during warm continuous retrograde cardioplegia we obtained blood gases from three regions of the heart in 141 consecutive patients undergoing coronary artery bypass grafting, aortic valve replacement, or both. Right heart perfusion was determined by blood gases from the right coronary artery orifice, acute marginal, or posterior descending coronary arteries; circumflex or lateral wall perfusion was determined by samples from obtuse marginal or intermediate coronary arteries; and anterior wall/septal perfusion was determined by left anterior descending and diagonal coronary artery blood gases. Warm continuous retrograde cardioplegia flow ranged from 150 to 300 mL/min depending on heart size. A mean of 4 +/- 1 samples/patient were obtained. RESULTS: There were no regional differences in postcapillary pH, carbon dioxide tension, or CO2 production during warm continuous retrograde cardioplegia. Oxygen tensions were lower in the right and anterior/septal regions of the heart, implying more O2 uptake. No regional acidosis, consistent with poor perfusion, could be detected. CONCLUSIONS: We conclude that, unlike experimental models, regional myocardial perfusion, including the right heart, is uniform during "high-flow" warm continuous retrograde cardioplegia in humans.

Carbon Dioxide↗
PubMed1996

Neurologic sequelae of deep hypothermic circulatory arrest in cardiac transplant infants.

BACKGROUND: Considerable controversy exists experimentally and clinically regarding adverse neurologic effects that may follow deep hypothermic circulatory arrest. Moreover, the techniques of DHCA have never been standardized. METHODS: We prospectively studies the neurodevelopmental outcome in 38 infants undergoing cardiac transplantation using DHCA before the age of 4 months (mean age, 37.0 days). Neurodevelopmental outcome in the 22 boys and 16 girls was tested up to 2.5 years after transplantation using Bayley scale of infant development. Bayley scores were compared with the rate of core cooling and the length of DHCA in all patients. Deep hypothermic circulatory arrest was accomplished using an asanguineous prime resulting in hematocrits of 5% +/- 5% and ionized Ca2+, 0.4 +/- 0.1 mmol/L. No surface precooling was used, but the head was packed in ice. Mean cooling time was 14.0 +/- 3.5 minutes, resulting in rectal temperatures of 18 degrees +/- 2.5 degrees C. Duration of DHCA ranged from 42 to 70 minutes (mean duration, 56.0 +/- 6.6 minutes). RESULTS: Postoperatively, the mean Bayley psychomotor development index was 91 (range, 50 to 130) and mental development index was 88 (range, 50 to 130). No relationship was found between either the rate of cooling or the duration of DHCA and Bayley scores (r = 0.227 and r = 0.322, respectively). CONCLUSIONS: These data suggest that neither the rate of cooling nor DHCA times between 42 and 70 minutes using profoundly low hematocrits and low ionized calcium levels has any measurable effect on neurologic outcome up to 2.5 years postoperatively. It is possible that adverse neurologic outcomes from DHCA reflect particular methods of achieving DHCA.

Central Nervous System↗
PubMed1996

Transplantation as a primary treatment for hypoplastic left heart syndrome: intermediate-term results.

BACKGROUND: Hypoplastic left heart syndrome is a lethal malformation. For the last 10 years, orthotopic cardiac transplantation has been our preferred treatment for infants with hypoplastic left heart syndrome. METHODS: One hundred seventy-six infants with hypoplastic left heart syndrome were entered into a cardiac transplant protocol between November 1985 and November 1995. Interventional procedures to stent the ductus arteriosus or enlarge the interatrial communication were performed in 8 and 35 patients, respectively. Thirty-four patients (19%) died during the waiting period, and 142 infants underwent cardiac transplantation. Age at cardiac transplantation ranged from 1.5 hours to 6 months (median, 29 days). The majority of grafts were oversized, and the median graft ischemic time was 273 minutes (range, 60 to 576 minutes). The implantation procedure used a period of hypothermic circulatory arrest ranging from 23 to 110 minutes (median, 53 minutes). Repair of other significant defects included interrupted aortic arch and total or partial anomalous pulmonary venous connection. RESULTS: There were 13 early and 22 late deaths. Patient actuarial survival at 1 month and at 1, 5 and 7 years was 91%, 84%, 76%, and 70% respectively. Half of the late deaths were due to rejection. Severe graft vasculopathy was confirmed in 8 patients. Retransplantation was performed in 5 patients for graft vasculopathy 4 and rejection 1. Lymphoblastic leukemia developed in 1 patient 3 years after cardiac transplantation. CONCLUSIONS: Cardiac transplantation can be performed in infants with hypoplastic left heart syndrome with good operative and intermediate-term results. Improved survival can be achieved with increased donor availability, better management of rejection, and control of graft vasculopathy.

Actuarial Analysis↗
PubMed1996

The use of larger size pulmonary homografts for the Ross operation in children.

Nine pediatric patients received an adult size cryopreserved pulmonary homograft for right ventricular outflow tract reconstruction as part of the Ross procedure. The early postoperative results are excellent. It is suggested that a full, adult size pulmonary homograft should be used in the future in pediatric patients undergoing the Ross procedure.

Adolescent↗
PubMed1996

Rapid freezing of mouse embryos in ethylene glycol at different preimplantation stages.

The objectives of this study were to examine the effects of a rapid freezing protocol on the survival and in vitro development of mouse embryos cryopreserved in ethylene glycol (EG) at different preimplantation stages, and secondly, to investigate the effect of exposure to 3.0 M EG with 0.25 M sucrose on the survival and in vitro development of mouse embryos without freezing at different developmental stages. To perform the rapid freezing procedure, embryos were equilibrated in Dulbecco's phosphate buffered saline (DPBS) containing 3.0 M EG and 0.25 M sucrose (freeze medium) for 20 min and loaded into 250 microliters straws in a single column of freeze medium. The straws were held in liquid nitrogen (LN2) vapour for 2 min and immersed into LN2. Embryos were thawed in a 37 degrees C water bath for 20 sec and transferred to DPBS supplemented with 0.5 M sucrose (rehydration medium) for 10 min and cultured for 24 to 96 h in HTF (Human Tubal Fluid) plus 4 mg/ml BSA (Bovine Serum Albumin). Significant differences were found in the survival and development of mouse embryos at different developmental stages rapid frozen in EG and sucrose: two cell 43/84 (51%), 4-8 cell 44/94 (47%), morula and early blastocyst 56/70 (80%), expanding and expanded blastocysts 10/59 (17% (p < 0.05). These data indicate that the developmental stage in which mouse embryos are subjected to this quick freeze protocol affects survival and development in vitro and the majority (80%) of morula and early blastocyst stage embryos survive the procedure. No significant differences were observed in the in vitro developmental capacity of embryos at different developmental stages after treatment with high concentrations (3.0 M) of EG solution without freezing. Further investigations are underway to better understand the reasons for different survival rates of embryos frozen at different developmental stages using the present procedure.

Animals↗
PubMed1995

Pretransplant risk factors and causes of death or graft loss after heart transplantation during early infancy. Pediatric Heart Transplant Team, Loma Linda.

BACKGROUND: This study was performed to report causes of death or graft loss and to identify possible pretransplant risk factors for death or graft loss in infants after heart transplantation. METHODS AND RESULTS: Pretransplant risk factors were compared for 153 infants registered for heart transplantation within 90 days of life and transplanted from November 1985 to June 1994. Factors assessed were diagnosis, age at transplantation, race, weight, blood type, sex, donor/recipient blood type match, sex match, weight ratio, fetal registration, locale of pretransplant waiting period, mechanical ventilation, ischemic time, and the need for atrial septostomy or septectomy pretransplantation. No factor was associated with death or graft loss at 1 month or 1 year. Causes of death or graft loss were determined using clinical course and pathology data when available. Death or grafts lost at 1 month, 1 year, and > 1 year were 14, 13, and 15, respectively. Causes of death or graft loss expressed as a percent (at 1 month, 1 year, and > 1 year, respectively) were acute rejection (14, 23, 27), chronic rejection and posttransplant coronary disease (0, 8, 47), infectious causes (21, 15, 13), early graft failure (21, 0, 0), technical issues (21, 23, 0), chronic graft dysfunction (0, 15, 0), and miscellaneous (21, 15, 13). The graft loss rate at 1 year was significantly correlated (linear regression, r2 = .66; P < .05) with the year of transplantation. Actuarial survival in this population was 91% at 1 month, 81% at 1 year, and 73% at 3 years. CONCLUSIONS: Heart transplantation in the young infant can be performed with acceptable short-term and midterm results. Causes of death or graft loss and survival are similar to adult data. No pretransplant risk factors were identified. The experience level of the transplant team members affects survival. The diagnosis and management of rejection remain a major challenge.

Actuarial Analysis↗
PubMed1995

Growth of oversized grafts in neonatal heart transplantation.

BACKGROUND: Because of the severe shortage of neonatal organ donors, oversized cardiac allografts are frequently transplanted. This study examined body and graft growth of neonates who receive an oversized heart. METHODS: We studied 51 neonates, who received transplants between November 1986 and August 1992, for changes in body weight, left ventricular mass, and end-diastolic volume measured at 1 week, 1, 3, and 6 months, and yearly after cardiac transplantation. Patients were divided into two groups according to donor/recipient weight ratios: the normal group, where the donor/recipient weight ratio was 1.5 or less (1.06 +/- 0.05; n = 24), and the oversized group, where the donor/recipient weight ratio was more than 1.5 (2.22 +/- 0.10; n = 27). RESULTS: After cardiac transplantation, body weight increased continuously in both groups with no difference between groups. In the oversized group, left ventricular end-diastolic volume at 1 week and left ventricular mass at 1 week and 1 month were significantly higher than those in the normal group (p < 0.01). In the normal group, end-diastolic volume and left ventricular mass increased continuously. In the oversized group, however, left ventricular mass significantly decreased until 3 months after cardiac transplantation and then increased continuously, whereas end-diastolic volume increased continuously throughout the posttransplantation period. CONCLUSIONS: These data suggest that oversized cardiac allografts shrink at first and then grow as the recipient grows. There appears to be a size adaptation of the large cardiac allograft to accommodate to the reduced requirements of the neonate.

Body Surface Area↗
PubMed1995

Percutaneous transluminal coronary angioplasty failures in patients with multivessel disease. Is there an increased risk?

In recent years, there has been a nationwide trend toward performing percutaneous transluminal coronary angioplasty in patients with multivessel coronary artery disease. The clinical course of 57 consecutive patients who required emergency first-time coronary artery bypass grafting operations were reviewed to assess for difference in outcome between the 28 patients (49%) with single-vessel disease and the 29 patients (51%) with multivessel disease. The two groups were similar in preoperative characteristics except for a higher proportion of chronic obstructive pulmonary disease in the patients with multivessel disease (p = 0.03). Twice as many patients with multivessel disease were in shock (single-vessel disease = 4 [14%], multivessel disease = 8 [28%], p = not significant) en route to the operating room and significantly more patients with multivessel disease required on-going cardiopulmonary resuscitation (single-vessel disease = 0 [0%], multivessel disease = 5 [17%], p = 0.03). Significantly more coronary artery bypass grafts were placed in the patients with multivessel disease (single-vessel disease = 1.5 +/- 0.6, multivessel disease = 2.9 +/- 0.7, p < 0.01), which required longer aortic clamping time (p = 0.02) and cardiopulmonary bypass time (p < 0.01). There were seven postoperative deaths; all but one occurred in patients with multivessel disease (single-vessel disease = 1 [4%], multivessel disease = 6 [21%], p = 0.05). According to multivariate analysis, incremental risk factors of mortality were preoperative shock (p < 0.01), urgent or emergency percutaneous transluminal coronary angioplasty (p = 0.06), and multivessel disease (p = 0.12). Despite a similar incidence of myocardial infarction (single-vessel disease = 8 [29%], multivessel disease = 12 [41%], p = not significant), patients with multivessel disease had a higher incidence of cardiac morbidity (single-vessel disease = 4 [14%], multivessel disease = 11 [38%], p = 0.04) and noncardiac morbidity (single-vessel disease = 4 [14%], multivessel disease = 12 [41%], p = 0.02). By multivariate analysis, incremental risk factors of morbidity were preoperative shock (p < 0.01), multivessel disease (p = 0.02), and ejection fraction < 50% (p = 0.07). In the subset of patients with multivessel disease, preoperative shock, ejection fraction < 50, and an age of 60 years or greater were associated with higher morbidity and mortality. In conclusion, the risk of percutaneous transluminal coronary angioplasty failure is considerably higher in patients with multivessel disease. In certain subsets of patients with multivessel disease, coronary artery bypass grafting would be a safer procedure when compared with percutaneous transluminal coronary angioplasty for initial myocardial revascularization.

Age Factors↗
PubMed1995

Successful survival of primates receiving transplantation with "dead," nonbeating donor hearts.

A paucity of donor organs is the principal limitation in human heart transplantation. Prompted by our short-term studies of reanimating "dead" donor hearts in sheep, we applied the same reperfusion modifications in juvenile baboons to determine human applications in an anoxic arrest model (as occurs when non-brain-dead patients are extubated and allowed to die). Ten juvenile baboons (mean weight 3.6 kg) were studied. Five baboons were used as donors. After being anesthetized, donors were pretreated with methylprednisolone (Solu-Medrol), 50% dextrose, nifedipine, and prostaglandin E1 and then paralyzed and extubated. Donors became pulseless at 7 +/- 1 minutes and had electric arrest 9 to 18 minutes after paralysis. The five donors were left undisturbed and warm for 15, 22, 30, 30, and 31 minutes, respectively, after asystole. They were then given 250 ml of 4 degrees C Roe's crystalloid cardioplegic solution via the aortic root and the hearts were explanted into iced Euro-Collins solution. Five baboons served as recipients. After donor harvest, recipients were placed on cardiopulmonary bypass, given prostaglandin E1, and cooled to 18 degrees C; circulatory arrest was instituted and the recipient's heart excised. The donor heart was transplanted in an orthotopic position. Before reinstitution of bypass, 250 ml of terminal leukocyte-depleted blood cardioplegic solution was given, then bypass was restarted and the hearts were reperfused for 60 minutes. All animals were weaned from bypass without the use of inotropic agents. All animals were extubated within 2 to 4 hours after bypass and received standard immunosuppression. Peak creatine kinase MB/total creatine kinase ratio was 0.2% +/- 0.2%. Postoperative ejection fractions by echocardiography were 75% to 80% (mean 76%). Animals survived 1, 9, 13, 16, and 34 days, with three deaths caused by acute rejection and one each by stroke and diarrhea/dehydration. Pathologic findings showed no areas of fibrosis or ischemic damage. We conclude that successful reanimation and engraftment can be achieved with the use of the asystolic primate heart; this work suggests that human application is realistic and could greatly expand the donor pool.

Animals↗
PubMed1995

Psychological obstacles to job or career change in late life.

Four studies involving middle-aged and older workers were conducted to (a) explore perceived obstacles to adaptive job or career changes in later-life, and (b) develop an instrument with which to identify older adults who might be more sensitive to such obstacles. A reliable instrument was developed which reflected three broad categories of perceived risk: (a) age-inappropriateness of the change, (b) potential for age-discrimination, and (c) risk of hastened obsolescence. As evidence for the convergent validity of the instrument, the results indicated a heightened sensitivity to job change obstacles among respondents with: (a) age-sensitized concerns about job and financial security, (b) poorer psychological adjustment to a plateaued career, and (c) poorer psychological and social adjustment to their own aging.

Age Factors↗
PubMed1994

The role of anti-pig antibody in pig-to-baboon cardiac xenotransplant rejection.

The role of naturally produced antibody in discordant xenograft rejection is still uncertain. Twelve orthotopic pig-to-baboon heart transplants (HTx) were performed. In 2 baboons, no antibody adsorption (AbA) was performed. In 5 baboons, AbA with a pig lung was performed during circulatory arrest. In 5 baboons, AbA and blood exsanguination at the beginning of cardiopulmonary bypass (CPB) were performed. Baboons were divided into 2 groups; group 1 (n = 4) died within 24 hr of HTx and group 2 (n = 8) survived more than 24 hr. Mean survival period was 9.8 +/- 3.0 hr in group 1 and 151 +/- 33 hr in group 2. Baboon anti-pig antibody (Ab) was measured before CPB, before circulatory arrest, during AbA, at the end of CPB, and daily after HTx. Anti-RBC Ab was measured by the titration method at temperatures of 4 degrees C and 37 degrees C (RAb-4 and RAb-37). Anti-endothelial cell Ab (EAb) and anti-white blood cell Ab (WAb) titers were measured with ELISA. RAb titration > or = 1/4 and EAB and WAb > or = 1/256 were determined to be seropositive (S(+)). S(+) rate of RAb-37 at the end of CPB (endCPB) in group 2 was significantly higher than that in group 1 (8/8 vs. 1/4; P < 0.05). The seronegative (S(-)) rates of RBC-4 and EAb (endCPB) in group 2 were higher than those in group 1 (7/8 vs. 1/4 and 6/8 vs. 1/4, respectively), but not significantly. There was no difference in S(-) rate of WAb (endCPB) between group 1 and group 2. More than 4-fold decrease in RAb-4 and RAb-37 by AbA with a pig lung was observed in 5 and 7 of 8 baboons, while EAb and WAb did not change by AbA. In all of group 2, RAb-4 reverted to S(+) within 3 days after HTx. One baboon had no rejection episode and died of infection 16 days after HTx (baboon 16); however, it also became S(+) for RAb-4 a day after HTx until death. In 4 of group 2, RAb-37 became S(+) 1 or 2 days before death by rejection. Baboon 16, however, became S(+) for RAb-37 7 days after HTx and S(-) again 9 days after HTx until death. EAb became S(+) in all of group 2, but 5 of them survived more than 5 days after seroconversion.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

Pericardioperitoneal shunt: an alternative treatment for malignant pericardial effusion.

The treatment of 37 consecutive cases of symptomatic malignant pericardial effusion over a period of 13 years was retrospectively analyzed. The most common diagnoses were lung cancer (59%) and breast cancer (11%). In the most recent 4 patients, the Denver pleuroperitoneal shunt was used to drain the pericardial effusion into the peritoneal cavity. In each case, the procedure was performed under local anesthesia, and the patient was discharged 2 to 4 days later without complications. Three of the patients subsequently died of the disease process without evidence of cardiac failure or tamponade during 6-month follow-up. The more traditional means of pericardial drainage, the subxiphoid approach (14 patients) and the anterior thoracotomy approach (19 patients), were associated with higher postoperative morbidity (21% and 53%, respectively) and mortality (7% and 42%, respectively). Because of the small number of patients treated by pericardioperitoneal shunting, a significant difference was demonstrated only in the length of hospital stay (shunt, 2.8 +/- 0.5 days; subxiphoid, 11.2 +/- 4.6 days; thoracotomy, 14.9 +/- 6.1 days). Median survivals were essentially the same (shunt, 3.5 months; subxiphoid, 2.7 months; thoracotomy, 1.2 months). It is apparent that the pericardioperitoneal shunt, although a much simpler procedure, can accomplish similar palliation effectively in the treatment of malignant pericardial effusion.

Breast Neoplasms↗
PubMed1994

Simple approach for extrapericardial placement of defibrillator patches via median sternotomy.

The intrapericardial placement of implantable cardioverter defibrillator patches has been associated with a variety of complications due to the patch-epicardial interface. Extrapericardial placement of defibrillator patches minimizes these problems. We describe a simple and reproducible technique to achieve this goal whenever a median sternotomy approach is used.

Defibrillators, Implantable↗
PubMed1994

Staged repair using omentum for posttraumatic aortoesophageal fistula.

Aortoesophageal fistulas from traumatic thoracic aortic pseudoaneurysms are almost uniformly fatal. We report a case of a young woman who nearly exsanguinated soon after diagnosis. Immediate operative intervention consisted of prosthetic graft replacement of the pseudoaneurysm and pleural patch coverage. Definitive treatment of the esophageal perforation was necessary later for mediastinal sepsis. Primary repair of the esophagus accompanied by mobilization of the omentum into the space between the esophageal closure and the prosthetic graft led to a successful outcome.

Adult↗