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Biomedical subjects

C S Weldon

Publications and source records attributed to C S Weldon.

At least 19 recordsLinked to original sources
PubMed1979

Use of saphenous vein to extend and relocate coronary arteries: clinical experience during extensive reconstructive operations of the aortic root.

Eight patients with advanced disease of the aortic root involving the origins of the coronary arteries have been operated on with resection of the entire aortic root including the ostia of the coronary arteries. Reconstruction was performed by insertion of a composite prosthesis; extension and relocation of the proximal portion of the coronary arteries was accomplished with saphenous vein segments. Two patients had infected aortic valve prostheses, three patients had acute aortic dissection and three had annuloaortic ectasia. Seven of eight patients survived the operation, the only operative death occurring in a patient submitted to an operation in a shock state following rupture of the aorta. There was, however, a high incidence of subsequent late deaths resulting from continued infection and from central circulatory failure. An analysis of this series of patients suggests the possibility that a reconstruction that relocates and extends the proximal portion of the coronary circulation may provide a total blood flow that is inadequate or inappropriate, and further suggests that the methods used in the reconstruction of the proximal circulation may be critical to the prevention of myocardial hypoperfusion.

Adult↗
PubMed1979

Comparison of bubble and membrane oxygenators in short and long perfusions.

Eighty patients had cardiopulmonary bypass (CPB), half having short (109 +/- 11 minutes) perfusions and half having long (188 +/- 14 min) perfusions. Twenty patients in each group were perfused with bubble oxygenators (Bentley, Harvey, or Galen) and 20 with membrane oxygenators (Modulung or Teflo). Hemodilution to a hematocrit value of 22.5% +/- 1.4% and hypothermia to 28 degrees +/- 2 degrees C were used in all patients. Complete hemograms, sequential multiple analyzer 18 tests, coagulation profiles, blood gases and pH, three immunoglobulins, and two complement fraction proteins were sampled as follows: three times before perfusion, one to ten times during perfusion, 1 hour immediately after perfusion, and 4, 24, and 48 hours postoperatively. Data in concentration terms were compared statistically and reported as mean and standard error for each subset. Additionally, rates of gain or loss were calculated in terms of quantity per liter of blood pumped per minute. During perfusion for both duration sets, use of a membrane oxygenator resulted in greater pump flows (4.55 +/- 0.15 L/min versus 3.75 +/- 0.11 L/min), lower total peripheral resistances (1,125 +/- 63 dynes.sec.cm-5 versus 1,652 +/- 115 dynes.sec.cm-5), and greater urinary outputs (9.4 +/- 1.1 ml/min versus 2.2 +/- 0.6 ml/min) than in the bubble oxygenator subsets. Comparisons of measured and calculated data in the immediate postperfusion interval showed no differences between bubble and membrane oxygenator subsets for short perfusions. In long perfusions, the membrane subset had lower plasma hemoglobin and white cell concentrations and generation rates, smaller (3 to 8 1/2 times) losses of IgG, IgM, C3 and shed blood necessitating less transfusion, and greater C4 losses. The membrane oxygenator systems used were more complex and costly and offered no advantages for short perfusion in adults. In anticipated long perfusions or where bleeding may be a problem, a membrane oxygenator appears more efficacious than bubble systems. For perfusions of less than 2 hours, membrane oxygenators had no biochemical or hematologic advantage over the bubble devices used in this study.

Blood Cell Count↗
PubMed1978

Percutaneous transthoracic aspiration needle biopsy.

An experience based on 1,211 patients has shown aspiration needle biopsy to be a valuable technique for diagnosing bronchogenic carcinoma and other localized intrathoracic lesions that are beyond the reach of the fiberoptic bronchoscope. In 896 patients with malignant intrathoracic neoplasm, the aspirate demonstrated malignant cells in 96%. A false cytological diagnosis of carcinoma occured in 2 patients, for a true positive rate of 99%. However, the true negative rate was only 87%. In 77% of 31 immunosuppressed patients, the causative agent of a focal infectious process was diagnosed. Pneumothorax was the only notable complication, occuring in 24% of patients, with 14% requiring chest tube drainage. The procedure is relatively simple and rapid, generally causes little patient discomfort, and can be performed in virtually any hospital.

Adolescent↗
PubMed1978

Reconstructive valve surgery.

Despite continued refinement of heart valve prostheses, valve replacement carries risks of thromboembolic, mechanical, and infectious complications, and long-term success is further limited by the eventual wear of prosthetic parts. In many patients with congenital or acquired valve diseases, valve function may be improved, if not restored, by reconstructive techniques, prosthetic replacement being thereby avoided or delayed. This review examines the current status of reconstructive procedures for management of diseased valves, with emphasis on long-term results and post-operative hemodynamic studies. In many instances the choice between reconstruction and replacement of a diseased valve remains controversial. The documented success of selectively applied reconstructive techniques, however, weighs against expedient decisions for prosthetic replacement and supports a continuing search for new techniques.

Aortic Valve↗
PubMed1978

Posterior ventricular aneurysm, severe mitral regurgitation, and rupture of the left ventricle after acute myocardial infarction: six-year survival after surgical correction.

Posterior ventricular aneurysm and severe mitral regurgitation due to acute myocardial infarction are rarely recognized during life. This report describes the successful surgical treatment of a patient with this combination of lesions who at operation was found to have rupture of the left ventricle as well. Aneurysmectomy, mitral valve replacement, and coronary artery bypass were performed with a gratifying late result. Aggressive investigation of patients with hemodynamic deterioration after posterior myocardial infarction may identify surgically correctable mechanical complications.

Adult↗
PubMed1978

Left ventricular aneurysm resection: indications and long-term follow-up.

Forty-four patients had resection of a chronic postinfarction left ventricular aneurysm. Operative indications were heart failure, angina, and ventricular arrhythmias. Twenty-six patients (59%) had coronary grafting in addition to aneurysmectomy. The operative mortality rate was 4.5% (2/44), and late mortality (mean follow-up, 31 months) was 17.9% (7/39). Preoperatively all patients were in New York Heart Association Functional Class III or IV; 91% were Class I or II postoperatively. Coronary bypass grafting did not increase the operative mortality rate, and long-term survival was similar between those receiving coronary grafts and those not receiving grafts. Postoperative ventriculograms were evaluated in 10 patients by means of a system of internal grids. Amount of regional myocardial contraction correlated well with the patient's postoperative functional capacity. It is concluded that ventricular aneurysmectomy in combination with coronary bypass grafting is safe and effective, resulting in marked improvement in the patients' functional capacity and longevity.

Adult↗
PubMed1978

Multiple valve replacement: changing status.

Review of our experience with multiple valve replacement over a 6-year-period revealed a recent marked reduction in operative risk. Operative mortality for 62 patients operated on before 1974 was 34%; for 44 patients operated on since 1974, mortality was only 11%. In both groups, mortality was clearly related to the preoperative cardiac functional status. Several recent technical advances including myocardial protection by topical hypothermia, shortened perfusion time, and the intraaortic balloon pump may all have contributed to the reduced operative risk.

Aortic Valve↗
PubMed1978

Surgical correction of congenital heart disease in the adult: experience with 139 patients.

Patients over 18 years of age who have undergone a surgical correction of a congenital cardiac malformation during the period 1968 through 1977 have been reviewed. Those patients with calcific aortic stenosis which was thought, but not proved, to have arisen in a congenitally malformed aortic valve, were excluded from the review. Patients with cystic medial necrosis of the aorta were similarly excluded. There were 139 patients in the series (age range from 18 years to 67 years). The most common defects were those involving the intra-atrial septum and the related great veins, 50%. Abnormalities involving the great arteries including patent ductus arteriosus and coarctation of the aorta accounted for 19%. Common defects of conal development including ventricular septal defects and Tetralogy of Fallot malformations accounted for 15%. Valvular abnormalities including pulmonic stenosis, aortic valve abnormalities and Ebstein's malformation of tricuspid valve accounted for 11.5%. Complex congenital malformations were relatively uncommon, 4%. There were two patients with a combination of acquired and congenital heart disease. There were two operative deaths in the series, both occurring in patients with complex forms of congenital heart disease (multiple ventricular septal defects, double outlet right ventricle). There were two additional postoperative hospital deaths, one occurring following repair of an atrial septal defect from massive pulmonary embolus, and another occurring six weeks following a Fontan procedure performed for tricuspid atresia. Thus, the hospital mortality for the series was 2.9%. This reviewed series reveals the incidence of operable congenital heart defects appearing in an adult cardiac surgical practice and demonstrates that surgical repair can be accomplished with a satisfactory low mortality rate.

Adolescent↗
PubMed1977

A new operation for far-advanced cystic medial necrosis of the aortic root.

Three patients with far-advanced cystic medial necrosis of the aorta, which had produced giant bulbous enlargement of the aortic root and severe aortic regurgitation, were operated on using a procedure not previously described. Measurements of the aortic valve annulus and ascending aorta were made from aortograms. A knitted polyester arterial prosthesis was sewn together to form a circle. This circular prosthesis was sewn to a 31 mm Björk-Shiley aortic valve prosthesis in the way that a tire is fitted onto a wheel. The resulting composite prosthesis, which had the same diameter as the aortic root, was used to replace the excised valve. In all cases a composite prosthesis measuring greater than 50 mm in diameter was used. In 2 of the 3 patients the ascending aorta was replaced with a tubular graft reshaped as a truncated cone. This reshaping was done by inserting multiple gussets into one end of the aortic prosthesis so that the flanged end fit precisely to the transverse aortic arch. Two patients are asymptomatic more than two years following operation. The third patient died suddenly of a ventricular arrhythmia on the twenty-third postoperative day.

Adult↗
PubMed1977

Perioperative mortality rate in patients with unstable angina selected by exclusion of myocardial infarction.

Coronary bypass surgery may be associated with an increased perioperative mortality rate in patients with unstable compared to stable angina. The mortality rate is excessively high when surgery is performed during evolving myocardial infarction. Elevated plasma MB CPK isoenzyme activity is a remarkably sensitive and specific marker of myocardial damage. Accordingly, we studied 111 patients with unstable angina to determine whether exclusion of patients with initially elevated MB CPK improves the perioperative mortality rate. Plasma MB CPK activity was assayed prior to catheterization and every 2 hours therafter. Of the 111 patients, 16, with initially elevated MB CPK activity, were excluded and managed medically. Catheterization was performed in 59 patients, and severe vessel obstruction was documented in 55. Coronary bypass surgery performed in 47 patients was associated with a mortality rate of 4 per cent. Thus, after exclusion of patients with evolving infarction by MB CPK isoenzyme analysis, catheterization and coronary bypass surgery in patients with unstable angina resulted in a mortality rate comparable to that in patients with stable angina.

Adult↗
PubMed1977

Long-term function of aortic homografts as the right ventricular outflow tract.

Physical examination, chest roentgenography, phonocardiography, and right heart catheterization were used to evaluate the function of composite aortic homografts inserted as right ventricular outflow tracts in 13 patients 1.8 to 7 years previously. All homografts in these patients who were followed for 2 or more years demonstrated calcification of the aortic wall, but valve leaflets were spared. Moderate pulmonary insufficiency was present in eight patients with single cusp partial homografts, but was well tolerated in all. Homograft valve insufficiency was mild in five patients with complete homografts. No patient had an outflow tract gradient greater than 32 mm Hg. The average gradient was 18.5 +/- 2.7 (SEM) mm Hg. Abnormality of pulmonary blood flow was found in three patients and could be related to previous Waterston or Potts anastomoses. No late morbidity due to homograft degeneration has occurred and the long-term function of these conduits appears to be good.

Adolescent↗
PubMed1977

Postoperative investigation of left ventricular aneurysm resection.

We reviewed 35 patients undergoing resection of a chronic postinfarction left ventricular aneurysm. There was 5.7% operative mortality. Of the long-term survivors, 80% are functional class I or II. Ten patients had postoperative left ventriculograms studied by means of a computerized analysis of endocardial motion using internal orthogonal and radial grids. Postoperative end-diastolic volumes were much greater than normal and large akinetic areas were present although there was good improvement in the patient's functional capacity. Grid analysis of endocardial motion correlated better with the patient's postoperative clinical status than did measurements of end-diastolic pressure and volume, ejection fraction, or visual inspection of the postoperative left ventriculogram.

Adult↗
PubMed1976

Results of surgery for congenital supravalvular aortic stenosis.

Of eight children aged 3 to 15 years with surgical correction of severe supravalvular aortic stenosis, 6 were evaluated 7 to 44 months later by repeat cardiac catheterization and aortography. Prosthetic patch angioplasty was performed in all cases. Preoperative systolic gradients ranged from 40 to 90 mm Hg (average 70); postoperative gradients ranged from 0 to 20 mm Hg (average 11). The postoperative anglographic appearance of the ascending aorta was near normal in all six patients, and none had new aortic valve insufficiency. These results of surgery for supravalvular aortic stenosis are judged to be excellent.

Adolescent↗
PubMed1976

Late clinical problems with Beall model 103 and 104 mitral valve prostheses: hemolysis and valve wear.

The purpose of this study was to determine the influence on hemolysis of the spatial orientation of the struts in the Beall mitral valve prosthesis, Models 103 and 104. Thirteen pairs of patients were selected to match struts oriented parallel and perpendicular to the left ventricular outflow tract axis. The average time after operation was 3.73 years. Complete blood counts and relative serum chemistry values were determined.

Adult↗