Biomedical subjects
Publications and source records attributed to L W Stephenson.
Fistulas from the left main coronary artery to the right atrium are unusual lesions that have been treated by fistula ligation. The present report of a case treated by a combined transaortic and transatrial approach stresses the ease and advantages of this technique.
Results obtained with Blalock-Taussig, Waterston, and polytetrafluoroethylene (PTFE) shunts were compared in 67 cyanotic infants less than 2 weeks of age. A different shunt was preferably used at each of three institutions. The incidences of early shunt failure (3 out of 21, 14%), mortality after revision of early shunt failure (0 out of 3), and overall hospital mortality (1 out of 21, 5%) were all lowest for the PTFE shunt. Incidence of congestive heart failure secondary to excessive flow was comparable for the Blalock-Taussig and PTFE shunts, both of which were lower than the Waterston shunt. Cumulative probabilities of late shunt adequacy were calculated for hospital survivors. At 1 year, all shunts provided comparable adequate palliation (greater than 80%). Probability of late shunt failure was significantly higher (p = 0.04) for the PTFE shunt at 3.5 years. Results suggest that the PTFE shunt may be the safest and most effective shunt in neonates, but that elective shunt replacement or total repair may be warranted in the first or second year of life.
Origin of the left coronary artery from the right pulmonary artery has rarely been documented. This is the first such case in a heart with an intact ventricular septum and paraductal coarctation of the aorta. Although an antemortem diagnosis was made and the anomalous left coronary artery was ligated, the patient, a 3 1/2 month old infant, died 1 day after surgery. Autopsy confirmed the diagnosis, but revealed that the left coronary artery was dominant. It is believed that the fatal outcome in the infant was, in part, due to the dominance of the left coronary artery and the effects of the coarctation on the already ischemic left ventricle.
The CT features of endobronchial granular cell myoblastoma are reported in an acknowledged heavy smoker without pulmonary complaints. Computed tomography confirmed the intraluminal location of the mass, demonstrated associated atelectasis, and detected the lack of adenopathy or invasion into the mediastinum, thus contributing significantly to surgical planning.
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A temporary left ventricular assist system utilizing an improved left atrial catheter and centrifugal pump was developed and tried in 22 anesthetized sheep to test the hypothesis that prostacyclin (PGI2) and ionically bound heparin-coated surfaces could prevent thrombosis in this perfusion system without inhibiting soluble, circulating coagulation factors. Sheep were perfused at 53.6 ml/kg/min (standard error, 1.5) from left atrium to aorta for two hours. The pump maintained flow at left atrial pressures of 3 to 4 mm Hg. As expected, systemic heparin inhibited coagulation, mildly activated platelets, and prevented thrombosis in uncoated perfusion circuits and wounds. Infusion of PGI2 (30 ng/kg)min) without systemic heparin or heparin-bonded extracorporeal surfaces prevented platelet activation and did not alter coagulation measurements; however, bleeding times increased and thrombi formed in every circuit. When heparin was ionically bound to all extracorporeal surfaces, infusion of PGI2 completely prevented thrombosis within the circuit, inhibited platelet activation, and did not alter coagulation measurements. Blood spontaneously clotted in three of six thoracotomy wounds during perfusion. When PGI2 infusion was stopped, heparin-coated surfaces alone failed to prevent thrombosis within the system in 3 of 5 animals. The combination of PGI2 infusion and heparin-coated extracorporeal surfaces prevents thrombosis within the perfusion circuit without inhibiting soluble coagulation factors. This method, using the assist system, overcomes many of the implementation and bleeding problems associated with other temporary left ventricular assist devices.
Thirteen premature infants receiving mechanical ventilation for respiratory distress syndrome developed pneumopericardium. All had high peak inflation pressures (mean, 42 mm Hg; range, 26 to 60 mm Hg), and all were on positive end-expiratory pressure (PEEP) ventilation (mean, 3.1 mm Hg; range, 2.1 to 5.7 mm Hg) at the time that pneumopericardium occurred. Arterial blood gases, indices of respiratory support, and hemodynamic data were reviewed before and after the onset of pneumopericardium in all patients. There was a statistically significant increase in peak inflation pressure (PIP) over the 16 hours prior to onset of pneumopericardium (p less than 0.05). There was, however, no significant relationship between onset of pneumopericardium and other respiratory variables, including PEEP. In the majority of patients, pneumopericardium was associated with cardiac air tamponade. Various forms of treatment for pneumopericardium were attempted, including observation, needle aspiration, and insertion of pericardial tubes. Review of the therapy indicates that insertion of a pericardial tube under direct vision is the safest and most effective means of treating pneumopericardium in infants. These data also suggest that PIP is more important than PEEP in predisposing neonates with respiratory distress syndrome to pneumopericardium.
A patient is presented with partial absence of the right pulmonary artery, left coronary artery to bronchial artery fistula and systemic arterial desaturation with a patent foramen ovale. The various aspects of the syndrome are discussed and the rationale for nonoperative closure of the foramen is described.
Since 1971 we have seen 15 children with the diagnosis of purulent pericarditis. The causative organism was Hemophilus influenzae in seven, Staphylococcus aureus in three, and five were due to other organisms. In one child the diagnosis was unsuspected until autopsy. The other 14 patients were all treated with intravenous antibiotics to which the organism was sensitive. One child had an immediate pericardiectomy because of tamponade. The other 13 patients had pericardiocentesis for diagnosis and initial therapy. Pericardiocentesis alone resulted in recovery of four patients and failed in nine, including all seven patients with H. influenzae. These nine had recurrent tamponade or a persistent picture of sepsis that was unresponsive to repeated pericardiocenteses and necessitated operative intervention. The procedure used was subxiphoid tube drainage in two patients. One recovered and the other required further operation. The remaining seven patients were treated with pericardiectomy. All pericardiectomy patients recovered without complications or recurrent symptoms. Survivors are asymptomatic with no evidence of pericardial constriction. We recommend immediate pericardiocentesis for diagnosis and initial therapy. Early pericardiectomy should be performed if the causative organism is H. influenzae, if tamponade occurs after initial pericardiocentesis, or if fever persists despite appropriate antibiotics.
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The incidence of carcinoma of the esophagus is 1:10,000 for males. Esophageal carcinoma occurs less frequently in females. Tracheoesophageal fistula may occur as a complication of esophageal cancer. In this report, a brother and sister are presented who, although six years different in age, developed malignant tracheoesophageal fistulas within one month of each other. The probability of this occurring coincidentally is less than one in five hundred million. Each sibling had a different form of palliation with markedly different results. The first patient was treated with a Celestin tube which never provided good palliation. He suffered a rapid and miserable decline and death. The second patient was treated with substernal esophageal bypass using the stomach and exclusion of the thoracic esophagus. She has since undergone irradiation to the area of the fistula. She remains alive and well, physically active and eating a regular diet 23 months after surgery.
Six patients who survived episodes of coronary arterial spasm occurring immediately after coronary bypass grafting were followed up for 15 to 30 (mean 20) months after operation. In all patients coronary spasm occurred in an unobstructed dominant right coronary artery and caused inferior transmural ischemia. Sudden circulatory collapse occurred in five of the six patients as a consequence of acute coronary spasm. All patients were treated with nitroglycerin followed by nifedipine. No patient has had recurrent angina or other evidence of spontaneous coronary spasm since surgery. Cardiac catheterization studies, including ergonovine maleate testing, were repeated 3 to 12 months after surgery in five of the six patients. The right coronary artery and all bypass grafts were patent in all five. Four patients had new inferior wall motion abnormalities. Ergonovine provoked focal right coronary arterial spasm in one patient. It is concluded that manifestations of coronary spasm after myocardial revascularization range from asymptomatic S-T segment elevation to severe hypotension. These episodes of perioperative spasm may cause myocardial necrosis. Coronary spasm has not recurred in patients who survived perioperative spasm, but some patients may have a continued predisposition to development of coronary spasm late after surgery.
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Pleurodesis with a sclerosing agent was attempted in an animal model in which a pneumothorax with an active air leak was created. Adult rabbits had a small left thoracotomy and then a 1-cm controlled cut in the lung surface. Animals served as control, or tetracycline was administered. The chest tube was removed after the air leak stopped. Animals were sacrificed after 20 days. Group A was control rabbits (6); group B had powdered tetracycline placed at thoracotomy; group C, tetracycline solution, 2 ml/kg, 25 mg/ml (4); and group D, tetracycline solution, 1 ml/kg, 50 mg/ml (10). Control rabbits showed few adhesions, and the pleura appeared to be normal by histologic examination. There was a spectrum of results with tetracycline, but with the concentrated tetracycline solution (group D) histologic examination showed uniform pleurodesis and thickening of the pleura. In group D it took no longer for the pulmonary air leak to seal than with the group A (control) rabbits. We conclude that concentrated tetracycline solution is effective in causing pleurodesis even when an active air leak is present. The lung, however, must be kept expanded so that symphysis can occur between the visceral and parietal pleura.
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A rare form of vascular ring is presented consisting of a left cervical aortic arch, a right descending aorta, and a right ligamentum arteriosum in a symptomatic infant. The planning of its surgical interruption was complicated by absence of the left pulmonary artery and hypoplasia of the left lung. This case provides an exception to the surgical axiom that all vascular rings can be divided through the left side of the chest. It reveals the difficulty in evaluation of these lesions by barium swallow alone and emphasizes the importance of preoperative angiography to correctly define the anatomy. The surgical approach to a patient with an absent left pulmonary artery and hypoplastic lung requiring a contralateral thoracotomy is presented.
The effects of cardiopulmonary bypass with bubble and membrane oxygenator systems on platelet function were studied in 26 patients who had elective coronary arterial bypass grafts. Fourteen patients were perfused with spiral coil membrane oxygenator systems, 12 with bubble oxygenator systems. During and after bypass, platelet counts decreased in both groups; however, when corrected for dilution, platelet counts did not change significantly in patients perfused with membrane oxygenators and increased slightly but significantly in those perfused with membrane oxygenators and increased slightly but significantly in those perfused with bubble oxygenator systems. During and 1 hour after bypass, the concentration of adenosine diphosphate (ADP) required to cause complete aggregation increased in both groups. Plasma low affinity platelet factor 4 (LA-PF4) increased significantly during and after bypass in both groups. However, the concentration of platelet adenine nucleotides and LA-PF4, measured only in patients perfused with membrane oxygenator systems, did not change. Bleeding times increased postoperatively in both groups and 18 hour blood losses were similar. Cardiopulmonary bypass with membrane and bubble oxygenator systems causes qualitatively similar losses in sensitivity to ADP and similar increases in bleeding times. The mechanism by which platelets are altered during cardiopulmonary bypass in obscure but is not due to partial depletion of granule contents in patients perfused with membrane oxygenators.
Prostaglandin E1 (PGE1) is a vasodilator. Because the drug is metabolized by lung, we postulated a selective effect on pulmonary vasculature. Twenty-six patients aged 3 months to 16 year (mean, 6.5 years) were studied after repair of atrial septal defect (5), ventricular septal defect (10), tetralogy of Fallot (3), and other lesions (8). Fourteen patients also received nitroprusside. PGE1 (0.1 to 1.0 micrograms/kg/min) or nitroprusside (0.59 to 8.7 micrograms/kg/min) was infused through a central venous catheter until mean pulmonary or mean systemic arteria pressure decreases at least 10%. Prostaglandin E1 and nitroprusside both decreased mean systemic arterial pressure and systemic vascular resistance (P less than 0.05). Although both drugs caused an average decrease in pulmonary arterial pressure and resistance, nitroprusside produced a more consistent response. Side-effects limited the use of PGE1 in 5 patients. PGE1 is an effective vasodilator and has advantages for some patients, but it does not produce selective vasodilation of pulmonary vessels.