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Biomedical subjects

W J Wells

Publications and source records attributed to W J Wells.

32 records · Page 2Linked to original sources
PubMed1996

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↗
PubMed1995

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↗
PubMed1994

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↗
PubMed1994

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↗
PubMed1994

Aspergillosis of the posterior mediastinum.

Invasive pulmonary Aspergillus, although rare in the general population, represents an important cause of morbidity and mortality among immunosuppressed patients. However, mediastinal invasion by Aspergillus is very uncommon, with few cases documented in the literature. Among 13 immunosuppressed pediatric patients recently diagnosed with invasive pulmonary aspergillosis, 3 have had posterior mediastinal invasion with severe complications. Rupture of a mycotic aortic aneurysm occurred in 2 patients, one of whom was operated on successfully. The infection involved the spinal cord with severe neurologic sequelae in 2 patients. We report our experience to make our colleagues aware of this problematic disease, which may be more prevalent in the current population of highly immunosuppressed pediatric patients.

Adolescent↗
PubMed1994

Anomalous left coronary artery from the pulmonary artery. Significance of intercoronary collaterals.

Seventeen patients with an anomalous left coronary artery from the pulmonary trunk underwent surgical treatment and were evaluated, with a mean follow-up of 9.5 years. Analysis has included clinical symptoms cardiac laboratory tests, angiographic grading of intercoronary collaterals, echocardiographic and angiographic measurement of left ventricular function, surgical methods, and the postoperative outcome. Ten patients (59%) survived, and there were seven early deaths. The only significant variable relating to survival was the extent of preoperative intercoronary connections. In survivors, the postoperative left ventricular ejection fraction increased from 45% +/- 25% to 64% +/- 14% (p < 0.01). Nine of ten survivors are free of symptoms and have normal left ventricular function. Nevertheless, half of all created anastomoses were occluded within 2 years of the operation. We speculate that even if temporarily constructed, a dual coronary supply allows for left ventricular recovery and normalization of function.

Child↗
PubMed1989

Surgical problems of endocarditis in children.

Among 143 episodes of endocarditis experienced in children over a 38-year period from 1950 to 1988, 23 patients required surgical intervention, including 11 valve replacements, 2 valve repairs, 7 mycotic aneurysm resections (most related to coarctation or ductus), and 3 instances of debridement and repair of the ventricular septum. Left-sided vegetations associated with endocarditis have traditionally been managed surgically only if repeated emboli have occurred. Following the unfavorable outcome in several patients with large mobile vegetations on the mitral valve, we have adopted a more aggressive surgical approach to debride and repair left-sided valves involved with such vegetations.

Aneurysm, Infected↗
PubMed1986

Evidence for stable homodimers and heterodimers of gamma-glutamyltranspeptidase subunits under protein-denaturing conditions.

gamma-Glutamyltranspeptidase is synthesized as a core glycosylated propeptide (Mr 75,000) which is subsequently cleaved to yield a stable heterodimeric structure (subunit Mr 50,000 and 30,000). The propeptide represents an insignificant mass of the transpeptidase but higher molecular weight bands designated H1 (Mr 85,000) and H2 (Mr 100,000) are readily observed by protein staining or immunoblot analysis of the enzyme or crude membranes after SDS-polyacrylamide gel electrophoresis. Although H1 and H2 represent the predominant antigenic forms of transpeptidase in tissues which exhibit relatively low specific enzyme activity, neither their structure nor their physiological function is known. In order to determine the relationship between H1 and H2, and the large (L) and small (S) subunits of the transpeptidase, individual bands (H1, H2, L and S) of the purified renal enzyme were cut from a Coomassie-stained SDS gel, eluted and re-electrophoresed. Isolated S produced S and dimers of S (Mr 60,000), while isolated L produced L and dimers of L corresponding to H2. Equivalent mixtures of L and S also produced H1. Utilizing IgG affinity-purified against either L or S, immunoblot analysis confirmed that H2 is a dimer of L, and H1 is a heterodimer of L and S. However, monoclonal IgG which recognizes both transpeptidase propeptide and native heterodimer did not react with H1. Thus, it is clear that isolated L and S can form and maintain unique dimeric structures during SDS-polyacrylamide gel electrophoresis. With this information it should now be possible to ascertain the basis for the apparent predominance of H1 and H2 in non-renal tissues.

Animals↗
PubMed1981

Massive venous air embolism during cardiopulmonary bypass.

A massive bolus of oxygen was forced into the right atrium and venous system of a patient during cardiopulmonary bypass using a Bentley BOS-10 oxygenator. The unique design of the oxygenator canister provides an explanation for the event. Methods are outlined to avoid this type of venous embolism.

Coronary Artery Bypass↗
PubMed1981

The pathology of surgically excised aortocoronary saphenous vein bypass grafts.

The pathologic features of 60 surgically excised failed aortocoronary saphenous vein bypass grafts from 40 patients were reviewed. In 23 cases the grafts were occluded by intimal fibrosis. In five this was associated with thrombotic occlusion of the remaining lumen. The histologic findings in some of these cases indicated that thrombosis preceded intimal fibrosis. Seventeen patients had graft failure caused by advanced arteriosclerosis. In 13 this was associated with thrombotic occlusion, often due to rupture of atheromatous plaques. The average duration of these grafts was 6--7 years compared to an average duration of 3 years for graft failure caused by occlusive intimal fibrosis, and 7 months for those associated with fibrosis and organizing thrombosis. Vein graft in the arterial circulation are susceptible to atherosclerosis; this becomes a significant problem after approximately 5 years. The pathologic changes closely resemble coronary arteriosclerosis.

Adult↗
PubMedDate not supplied

Effect of balloon counterpulsation on myocardial ischemia as measured by intramyocardial carbon dioxide tension.

Ischemic injury of the heart following coronary artery occlusion is related to distribution of coronary blood flow and regional myocardial metabolic activity. Myocardial injury during regional ischemia has been studied by measuring tissue pCO2 with mass spectrometry, a parameter which reflects anaerobic cellular metabolism. Myocardial carbon dioxide tension has been used to evaluate the effect of unidirectional intra-aortic balloon pumping on ischemic injury resulting from acute coronary occlusion. In a group of ten dogs, balloon counterpulsation was begun immediately prior to left anterior descending coronary artery occlusion. A significant metabolic sparing effect was observed in counterpulsed dogs as compared to a control group. A decrease of 33% in PCO2 response was evident as compared to control. These results that early application of unidirectional intra-aortic balloon pumping may delay ischemic injury by improving regional oxygen supply/demand ratio to an area of acute ischemia.

Acute Disease↗