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Biomedical subjects

W J Wells

Publications and source records attributed to W J Wells.

At least 19 recordsLinked to original sources

Comparison of outcomes between living donor and cadaveric lung transplantation in children.

BACKGROUND: Long-term survival in lung transplant is limited by bronchiolitis obliterans (BOS). We compared outcomes in pediatric living donor bilateral lobar (LL) vs cadaveric lung transplant (CL). METHODS: Children were studied who had LL or CL with at least 1 year follow-up. Data collected included acute rejection episodes, pulmonary function tests (PFT), BOS, and survival. Mean age was 13.36+/-3.16 years in LL and 12.00+/-4.19 years in CL patients (p = 0.37, ns). RESULTS: There was no difference in rejection (p = 0.41, ns). CL had rejection earlier (2.48+/-3.84 months) than LL (13.60+/-10.74 months; p = 0.02). There was no difference in 12 month PFT. But at 24 months, LL had greater forced expiratory volume in 1 second (FEV1) (p = 0.001) and FEF25-71% (p = 0.01) than CL. BOS was found in 0/14 LL vs 9/11 (82%) CL after 1 year (p = 0.04). After 2 years, 0/8 LL and 6/7 (86%) CL had BOS (p < 0.05). LL had 85% survival vs 79% for CL at 12 months. At 24 months, LL survival was 77% vs 67% for CL. CONCLUSIONS: Pediatric LL had less BOS and better pulmonary function than CL. As BOS is a determinant of long-term outcome, we believe LL is the preferred lung transplant method for children.

Adolescent

Impact of respiratory syncytial virus infection on surgery for congenital heart disease: postoperative course and outcome.

OBJECTIVES: a) To describe the postoperative course and outcome of cardiac surgery in children with recent respiratory syncytial virus (RSV) infection; and b) to evaluate whether timing of surgery has any impact on the outcome. DESIGN: Retrospective case series. SETTING: Intensive care unit and medical and surgical wards of a teaching pediatric hospital. PATIENTS: Twenty-five children (aged 25 days to 3.5 yrs; median, 4 months) with congenital heart disease who had cardiac surgery within 6 months after RSV infection. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We reviewed the clinical course and outcome of all patients. The cardiac diagnoses included ventricular septal defect (n = 11), tetralogy of Fallot (n = 3), atrioventricular canal (n = 3), and others (n = 8). Thirteen patients had surgery during the same admission as RSV infection (group I), and 12 patients had surgery electively after being discharged to home after RSV infection (group II). Two patients in group I died; both of these patients had undergone total repair of tetralogy of Fallot within 2 wks after admission for RSV infection. Postoperative complications in group I patients included pulmonary hypertension (n = 5), adult respiratory distress syndrome (n = 1), tracheal stenosis (n = 1), left ventricular dysfunction (n = 1), pericardial effusion (n = 1), secondary bacterial or fungal infection (n = 7), and deep venous thrombosis (n = 1). Of all group I patients, the ones who were operated on early appeared to be at higher risk for complications, especially for postoperative pulmonary hypertension. No patient in group II died, and only two patients had minor complications (one had reactive airway disease, and the other had a transient superior vena cava syndrome after a bidirectional Glenn operation). CONCLUSIONS: Cardiac surgery performed during the symptomatic period of RSV infection is associated with a high risk of postoperative complications, especially postoperative pulmonary hypertension. These complications appeared to be more frequent and of greater severity in patients who had earlier surgery compared with those who had later surgery. More studies are needed regarding the proper timing of cardiac surgery in patients with congenital heart disease and RSV infection.

Cardiac Surgical Procedures

Neonatal thymectomy: does it affect immune function?

OBJECTIVE: The purpose of this study was to determine whether thymectomy in the newborn has a negative effect on immune function. METHODS: Twenty-five neonates (<30 days) who had thymectomy at congenital heart repair were prospectively studied to determine immune function. The percentage of T-cell subtypes including CD3 (all T cells), CD4 (helper T cells), and CD8 (suppressor T cells) was determined. In six patients, further testing of CD4 cells was done to determine whether they were newly formed, recent thymic emigrants (CD4, CD45, and RA+), or older educated lymphocytes (CD4, CD45, and RO+). Response to the mitogen phytohemagglutinin and to tetanus toxoid were determined, as were antibody titers to tetanus. Samples were drawn before the thymectomy, at approximately 3 months after immunization and at 1 year. Ten age-matched control patients were tested. At follow-up, parents were asked about infections. RESULTS: Prethymectomy T-cell subsets were all normal and comparable to controls. At 12 months, the percent of CD3 was significantly less than in the control group (48% +/- 3% versus 64% +/- 2% [mean +/- standard error of the mean]; p < 0.01) as was CD4 (31% +/- 2% versus 46% +/- 2% [mean +/- standard error of the mean]; p = < 0.01). CD8 did not drop. Surprisingly, the percent of CD4 that were recent thymic emigrants did not decrease significantly (50% +/- 8% versus 60% +/- 6% [mean +/- standard error of the mean]; p = not significant). Lymphocyte blastogenesis to phytohemagglutinin and tetanus toxoid and antibody to tetanus were all normal at 12 months. No patient required readmission for infection, and there were the expected number of minor infectious events (median 3; 95% confidence interval 1,4). CONCLUSION: Thymectomy in neonates results in a modest but significant decrease in T-lymphocyte levels, but there is no compromise in immune function.

Antigens, CD

Continuous versus intermittent furosemide infusion in critically ill infants after open heart operations.

BACKGROUND: Use of intravenous furosemide is generally avoided in critically ill neonates and infants soon after open heart operations to prevent fluctuations in intravascular volume and resulting circulatory instability. METHODS: To assess and compare the safety and efficacy of continuous versus intermittent intravenous furosemide, we undertook a prospective, randomized trial in 26 consecutive patients less than 6 months of age. Inclusion criteria were presence of low-output syndrome requiring inotropic support (24/26 patients) or pulmonary hypertension requiring vasodilator therapy (10/26 patients) within 6 hours of discontinuation of cardiopulmonary bypass. Eleven patients received 0.1 mg x kg(-1) x h(-1) continuous intravenous furosemide (group 1) and 15 received 1 mg/kg bolus every 4 hours (group 2) for 24 hours. Mean age (3.7 +/- 3.4 versus 1.8 +/- 2.5 months) and weight (4.6 +/- 2.1 versus 4.3 +/- 1.7 kg) were comparable. RESULTS: Group 2 infants showed slightly greater absolute urinary output (2.5 +/- 1.1 mL/kg per hour versus 3.3 +/- 1.1 mL/kg per hour, p = 0.05). However, urinary output per dose of drug was significantly larger in group 1 infants (1.0 +/- 0.4 versus 0.5 +/- 0.2 mL x kg(-1) x h(-1); p = 0.002) with lesser fluctuations (variance, 1.9 +/- 1.6 versus 3.8 +/- 2.1; p = 0.02) and fluid replacement needs (20.6 +/- 3.8 versus 51.8 +/- 14.4; p = 0.001). Electrolyte replacement requirements were similar. A trend toward greater hemodynamic instability in group 2 patients (heart rate variance 88.4 +/- 79.8 versus 128.3 +/- 82.7; p = 0.09; central venous pressure variance 2.8 +/- 1.90 versus 4.1 +/- 3.7; p = 0.07; mixed venous oxygen saturation variance, 32.3 +/- 27.6 versus 45.7 +/- 20.4; p = 0.06) was noted. All patients who completed the study protocol survived operation and were discharged home. CONCLUSIONS: We conclude that (1) commonly used doses of both intermittent and continuous intravenous furosemide infusion can be safely administered to critically ill neonates and infants as early as 6 hours after operation, (2) continuous infusion yields an almost comparable urinary output with a much lower dose of furosemide, and (3) intermittent administration is associated with greater fluctuations in urinary output and greater needs for fluid replacement therapy.

Cardiac Output, Low

Experience with living-donor lobar transplantation for indications other than cystic fibrosis.

OBJECTIVE: Since development of a living donor bilateral lobar transplantation protocol for patients with cystic fibrosis, our indications have expanded to include recipients with other diagnoses. METHODS: We report on our experience in eight patients with primary pulmonary hypertension, postchemotherapy pulmonary fibrosis, bronchopulmonary dysplasia, idiopathic pulmonary fibrosis, and obliterative bronchiolitis. The average age of the eight patients was 19.1 years (range 9 to 40). The mean preoperative carbon dioxide tension for the four patients who did not have primary pulmonary hypertension was 92 mm Hg (range 64 to 120 mm Hg), and the two patients with pulmonary fibrosis were intubated (one on high-frequency jet ventilation). Each recipient received a right lower lobe (n = 7) or middle lobe (n = 1) and a left lower lobe (n = 8) from a total of 16 donors representing various combinations of the recipient's family (n = 15) and an unrelated friend (n = 1). RESULTS: With an average follow-up of 1 year the overall survival is 75%. For the five patients followed up for at least 1 year, mean forced vital capacity was 80.6%, forced expiratory volume in 1 second was 75.6%, mid-forced expiratory flow was 64%, and diffusing lung capacity corrected for alveolar volume was 73% of predicted. For those patients with primary pulmonary hypertension, preoperative hemodynamics revealed mean pressures as follows: blood pressure 84.8 mm Hg, right atrial pressure 7.8 mm Hg, pulmonary artery pressure 71.3 mm Hg, pulmonary capillary wedge pressure 9.5 mm Hg, cardiac index 2.9 L/min per square meter, and pulmonary vascular resistance index 22.8 Wood units. Postoperative hemodynamics revealed a mean blood pressure of 84.3 mm Hg, right atrial pressure of 2.7 mm Hg, pulmonary artery pressure of 16 mm Hg, pulmonary capillary wedge pressure of 7.3 mm Hg, cardiac index of 4.2 L/min per square meter, and pulmonary vascular resistance index of 1.9 Wood units. CONCLUSIONS: Early results of living-donor bilateral lobar transplantation for diseases other than cystic fibrosis have resulted in satisfactory survival and pulmonary function. Additionally, patients with severe primary pulmonary hypertension have had dramatic normalization of their hemodynamics despite the limited amount of lung tissue transplanted. We believe that the data from this small cohort experience compares favorably with our larger series with cystic fibrosis and supports an expanded role for living-donor lobar transplantation in patients with alternate indications.

Adult

The clamshell incision for bilateral pulmonary artery reconstruction in tetralogy of Fallot with pulmonary atresia.

BACKGROUND: Patients with tetralogy of Fallot/pulmonary atresia often have bilateral pulmonary artery lesions, including diminutive central and peripheral vessels, major aortopulmonary collaterals, and distortion from previous operations. Staged procedures through lateral thoracotomies and median sternotomies have traditionally been used for repair. METHODS: Between October 1993 and December 1995, 10 patients 3 months to 15 years old with complex tetralogy of Fallot/pulmonary atresia underwent repair via a clamshell approach. Nine had undergone a mean of 2.8 +/- 0.8 previous operations (range 1 to 4). Indications for operation were repair of pulmonary artery arborization anomalies in 10 (4 unilateral, 6 bilateral), with unifocalization in 6 (2 unilateral, 4 bilateral). RESULTS: Eight of 10 patients had concomitant complete repair. There were no deaths at a mean follow-up of 17.1 +/- 4.0 months (range 12 to 26). Mean ventilation time was 3.7 +/- 2.1 days (range 1 to 14) and hospital stay 8.7 +/- 4.6 days (range 4 to 19). At follow-up, the peak right ventricular/left ventricular pressure ratio in patients who received complete repair was 0.44 +/- 0.13 (0.30 to 0.67). One patient (10%) required reoperation because of pseudoaneurysm of the main pulmonary artery 14 months after repair, and one had successful stent placement because of recurrent left and right pulmonary artery stenosis 8 months after repair. Two infants who underwent complete unifocalization and central pulmonary artery reconstruction are awaiting completion of repair. CONCLUSIONS: The clamshell approach to complex tetralogy of Fallot/ pulmonary atresia provides simultaneous exposure of bilateral central and peripheral pulmonary artery lesions and intracardiac pathologic conditions. This procedure appears safe and may decrease the number of operations required to complete repair of tetralogy of Fallot/pulmonary atresia in selected patients.

Adolescent

Successful repair of ectopia cordis using alloplastic materials.

Ectopia cordis is a very rare congenital anomaly associated with a high mortality rate. A successful repair of ectopia cordis with complete absence of sternum was achieved in a two-stage procedure. Initial management consisted of coverage of skin over the malpositioned heart using bilateral pectoral skin flaps. A second more definitive repair was undertaken at age 14 months. Four methyl methacrylate struts were used to reconstruct the anterior chest wall and were then covered with bilateral pectoralis major muscle flaps. At the 2.5-year follow-up there is no evidence of cardiopulmonary compromise and the development of the thorax appears normal. We advise that use of alloplastic materials is a valid option in managing this difficult congenital anomaly.

Bone Cements

Truncus arteriosus with total anomalous pulmonary venous return and interrupted arch.

An infant with truncus arteriosus, total anomalous pulmonary venous return of the supracardiac type and interrupted aortic arch distal to the left subclavian artery is presented. One-stage repair was performed in the newborn period using a 12-mm aortic homograft. Recovery was complicated by congenital stenosis of the left main bronchus. The cardiovascular status remains stable 2 years after repair.

Aorta, Thoracic

Repair of coarctation of the aorta in adults: the fate of systolic hypertension.

BACKGROUND: The benefit of coarctation repair in adults has been questioned by suggesting that hypertension may not be relieved by the operation and that surgical intervention may have no impact on the natural history of the disease. METHODS: To delineate the impact of surgical intervention on systolic hypertension, we conducted a retrospective review of 26 adults with a mean age of 32 +/- 10 years who underwent coarctation repair between 1987 and 1993. All patients were hypertensive (mean systolic blood pressure, 174 +/- 21 mm Hg; range, 140 to 220 mm Hg), and 18 patients (69%) were on a regimen of at least one hypertensive medication at the time of surgical admission. All patients underwent catheterization, and the mean peak systolic gradient across the coarctation was 61 +/- 25 mm Hg (range, 25 to 120 mm Hg). Operation included resection and end-to-end anastomosis (3 patients), resection with an interposition tube graft (6 patients), a bypass graft (11 patients), and patch angioplasty (6 patients). There was no hospital mortality or late morbidity. RESULTS: Intermediate follow-up was available at a mean of 2.3 +/- 2 years (range, 1 to 7 years). At last follow-up, the peak systolic gradient between the upper and lower body was trivial (< or = 10 mm Hg) in 23 patients (88%) and mild (11 to 20 mm Hg) in 3 (12%). All patients had significant improvement in systolic blood pressure (p < 0.001) compared to preoperative values, and the majority (23, 88%) were normotensive. More than half of the patients (14, 54%) were still on a regimen of antihypertensive medication at last follow-up, with a trend (p = 0.06) toward older patients requiring medication. CONCLUSIONS: Surgical repair of coarctation in adults is an effective, low-risk procedure, which results in a significant improvement in systolic hypertension and a decreased requirement of antihypertensive medications.

Adult

Living-donor lobar lung transplantation experience: intermediate results.

OBJECTIVE: Living-donor lobar lung transplantation offers an alternative for patients with a life expectancy of less than a few months. We report on our intermediate results with respect to recipient survival, complications, pulmonary function, and hemodynamic reserve. METHODS: Thirty-eight living-donor lobar lung transplants were performed in 27 adult and 10 pediatric patients for cystic fibrosis (32), pulmonary hypertension (two), pulmonary fibrosis (one), viral bronchiolitis (one), bronchopulmonary dysplasia (one), and posttransplantation obliterative bronchiolitis (one). Seventy-six donors underwent donor lobectomies. RESULTS: There were 14 deaths among the 37 patients, with an average follow-up of 14 months. Predominant cause of death was infection, consistent with the large percentage of patients with cystic fibrosis in our population. The overall incidence of rejection was 0.07 episodes/patient-month, representing 0.8 episodes/patient. Postoperative pulmonary function testing generally showed a steady improvement that plateaued by postoperative months 9 to 12. Fourteen patients who were followed up for at least 1 year underwent right heart catheterization; pressures and pulmonary vascular resistances were within normal ranges. Bronchiolitis obliterans was definitively diagnosed in three patients. Among the 76 donors, complications in the postoperative period included postpericardiotomy syndrome (three), atrial fibrillation (one), and surgical reexploration (three). CONCLUSIONS: We believe that these data support an expanded role for living-donor lobar lung transplantation. Our intermediate data are encouraging with respect to the functional outcome and survival of these critically ill patients, who would have died without this option.

Adolescent

One-stage repair of interrupted aortic arch, ventricular septal defect, and subaortic obstruction in the neonate: a novel approach.

BACKGROUND: One-stage repair of interrupted aortic arch, ventricular septal defect, and severe subaortic stenosis represents a surgical challenge. Techniques that use extracardiac conduits to bypass the subaortic area or involve transaortic or transatrial resection of the conal septum have shown limitations and have failed to reduce the high mortality rate associated with subaortic obstruction. METHODS AND RESULTS: A new operative approach was used in nine neonates (2.1 to 3.9 kg) who underwent one-stage repair of interrupted aortic arch (type B, eight patients; type C, one patient), ventricular septal defect, and severe subaortic stenosis. All patients had severe subaortic stenosis according to preoperative echocardiography (mean ratio of subaortic to descending aortic diameter, 0.63 +/- 0.08). With a transpulmonary (seven patients) or transatrial (two patients) approach and without resection of the conal septum, the ventricular septal patch was placed on the left side of the septum to deflect the conal septum anteriorly and away from the subaortic area. There were no early or late deaths. Median intensive care unit and hospital stays were 17 days (6 to 47 days) and 21 days (10 to 55 days), respectively. On follow-up echocardiography (1 to 29 months, median 12 months), no patients had significant residual subaortic obstruction and one patient had mild residual arch obstruction (20 mm Hg). Growth of the subaortic region was demonstrated in all patients (mean ratio of subaortic to descending aortic diameter, 1.20 +/- 0.10; < 0.001). CONCLUSIONS: Relief of severe subaortic stenosis during one-stage neonatal repair of aortic arch interruption and ventricular septal defect can be accomplished successfully without resection of the conal septum.

Aorta

Aortic root replacement with the pulmonary autograft in children with complex left heart obstruction.

BACKGROUND: The optimal surgical treatment of complex (multiple level or recurrent) left ventricular outflow tract obstruction (LVOTO) in infancy is controversial. Staged procedures expose the children to the need for reoperation, and currently available techniques of aortoventriculoplasty are associated with the morbidities of biological and mechanical prostheses. METHODS: Between July 1992 and January 1996, we have performed 24 aortic root replacements with the pulmonary autograft in pediatric patients (< 18 years). Of this group, 8 were infants and children with complex LVOTO aged 9 days to 22 months (mean, 8.6 +/- 8 months) and weighing 3.3 to 10.2 kg (mean, 6.3 +/- 2.6 kg). The diagnoses were interrupted aortic arch/ventricular septal defect/subaortic stenosis in 3, recurrent aortic stenosis in 2, aortic stenosis and subaortic stenosis in 1, and aortic stenosis/subaortic stenosis/mitral stenosis/regurgitation in 2. All patients had undergone one to three previous operative procedures (mean, 1.5 +/- 0.8 procedures/patient). Preoperative echocardiographic peak LVOT gradient was 71.7 +/- 25 mm Hg (range, 40 to 110 mm Hg) and aortic annulus size was 7.2 +/- 2.3 mm (range, 4 to 10.6 mm). The surgical technique included replacement of the aortic root with the pulmonary autograft combined with incision of the conal septum to relieve subaortic stenosis or accommodate for size discrepancy between the aortic and pulmonary autograft root and a pulmonary homograft placed in the right ventricular outflow tract. RESULTS: There were no perioperative or late deaths at follow-up (range, 2 to 25 months; mean, 13.5 +/- 8 months). Mean hospital stay was 15 +/- 17 days (range, 4 to 53 days). Three children had the following complications: diaphragmatic paresis (1), delayed pericardial effusion (1), and atrioventricular block requiring a pacemaker (1). In follow-up, echocardiographic findings showed absent aortic regurgitation in 3 and trivial aortic regurgitation in 5, and no significant LVOTO (mean peak gradient, 6.2 +/- 7.6 mm Hg; range, 0 to 16 mm Hg). Pulmonary homograft regurgitation was absent in 5, trivial in 2, and moderate in 1. Peak right ventricular outflow tract gradient by echocardiogram was trivial in 7, and a significant gradient of 55 mm Hg has developed in 1 infant. There were no infective or embolic complications during follow-up. CONCLUSIONS: Our experience shows that aortic root replacement with the pulmonary autograft can be performed in children with excellent clinical results. The technique of root replacement combined with ventriculoplasty allows definitive and simultaneous relief of complex and multiple-level obstructive lesions. Considering the growth potential of the pulmonary autograft, this should be regarded as the optimal treatment modality in infants with complex LVOTO:

Aorta, Thoracic

Successful use of transesophageal echocardiography during extracorporeal membrane oxygenation in infants after cardiac operations.

We report the use of transesophageal echocardiography in infants after cardiac operations while supported on extracorporeal membrane oxygenation. In all patients transesophageal echocardiography provided valuable information when standard transthoracic echocardiographic evaluation was limited by poor acoustic windows. This report describes the application of transesophageal echocardiography during extracorporeal membrane oxygenation after cardiac operations.

Cardiac Surgical Procedures

Living-related donor lobectomy for bilateral lobar transplantation in patients with cystic fibrosis.

Donor lobectomy has been performed in 14 patients enabling 7 recipients with cystic fibrosis to undergo bilateral living-related lobar pulmonary transplantation. Donors included 11 patients, 2 brothers, and 1 uncle. Donor mean age was 43 years (range 24 to 55 years). Their mean height and weight was 170 cm (range, 169 to 180 cm) and 72.4 kg (range, 55 to 90 kg), respectively, compared with 161 cm (range, 140 to 175 cm) and 42.4 kg (range, 27 to 55 kg), respectively, in the recipient group. Donor pulmonary evaluation consisted of a history and physical examination, chest roentgenogram and computed tomographic scan, spirometry with arterial blood gas measurement, echocardiography, and perfusion scanning. From each pair of donors, one was selected for right lower lobectomy and the other for left lower lobectomy. Standard lobectomy techniques were modified to facilitate implantation and optimize preservation of the donor lobes. On the right side, the middle lobe was removed and discarded in the first three donors to provide an adequate cuff of pulmonary artery and bronchus for implantation. With increased experience, this has proved not to be necessary. There have been no deaths and no long-term complications in the donor group. Prolonged postoperative air leaks occurred in the 3 patients who underwent right lower and middle lobectomies. All donors have been able to resume their previous lifestyles. Living-related donor lobectomy provides an alternative to cadaveric organs in select patients in need of pulmonary transplantation.

Adolescent

Transesophageal echocardiography in the postoperative child with an open sternum.

We report the use of transesophageal echocardiography in 3 children whose sternums remained open for several days postoperatively. In these patients transesophageal echocardiography provided critical information when transthoracic echocardiography was ineffective due to limited acoustic windows. This report points out the application of transesophageal echocardiography in children with chest wall distortion.

Cardiac Tamponade