Coronary artery aneurysms after angioplasty and atherectomy.

Coronary artery aneurysm formation after percutaneous transluminal coronary angioplasty and directional coronary atherectomy is unusual. We report the case of a left anterior descending coronary artery aneurysm that formed in such a patient. The left anterior descending coronary artery was bypassed and the aneurysm was plicated with the aid of coronary angioscopy. The English-language medical literature on the topic of coronary artery aneurysms is reviewed.

Cardiac valvular chondroma.

The case of a 36-year-old woman with a tricuspid valvular tumor is presented. The lesion was successfully resected through the right atrium. Histologic examination showed a chondroma arising in a cardiac valve.

Systematic survey of opinion regarding the thoracic surgery residency.

To summarize this rather wide-ranging study, let us review the high points. The future practice of thoracic surgery will be increasingly affected by governmental factors and will have even greater technological dimensions. To do this work, we must continue to attract high-caliber individuals, and this is best accomplished by the early and continuing involvement in the educational process of strong role models from our field. These future surgeons must be motivated to do good work and should have high ethical standards as well as maturity and high intelligence. Experienced, involved faculty leading the residents through a broad program that offers graduated assumption of clinical and leadership responsibilities will facilitate the development of mature clinical judgment. Residents must be taught the clinical skills necessary to do all thoracic operations, leaving subspecialization to postresidency fellowships. The educational program should be humane in its demands and collegial in its application. It should incorporate experiences beyond the operating room, including the opportunity to read, think, and interact with local mentors and colleagues from around the country. The requirements of certification should not be so rigid as to preclude the development of different pathways to the same end. Likewise, although the accreditation process must protect the resident from exploitation, it must not be so restrictive that it does not allow for educational innovation and justifiable differences among programs. These are the thoughtful opinions of our colleagues. They deserve serious consideration.

Experimental aortocoronary artery bypass grafting using a CO2 laser on the dog: acute experiment.

This study was designed to evaluate the feasibility of using laser tissue welding in aortocoronary bypass operation. Simulated aortocoronary bypass operations were performed on 10 dog hearts supported by extracorporeal circulation. Distal anastomoses between internal mammary artery and coronary artery were achieved using the laser technique, which includes four stay sutures of 7-0 polypropylene and tissue welding between the stays by the laser at a power level of 65 mW. Short-term luminal patency was 100% without stenosis by angiography. Microscopy and histology showed that CO2 laser caused medial change resulting in fusion with preservation of normal intimal morphology. The aortocoronary bypass operation using a CO2 laser is technically feasible, and this technique may open up a new method for patients with small peripheral coronary artery obstruction and for pediatric patients with certain conditions (eg, Kawasaki disease).

End-to-side and end-to-end vascular anastomoses with a carbon dioxide laser.

This study was designed to compare anastomoses performed with a carbon dioxide laser and conventional anastomoses performed with 7-0 polypropylene suture. In each of 80 rabbits, the divided left carotid artery was anastomosed by a continuous suture technique and the right carotid was anastomosed with a carbon dioxide laser. In each of 40 additional rabbits, both end-to-end and end-to-side laser anastomoses were performed on the same carotid artery. The laser technique involved the placement of three stay sutures (end-to-end technique) or four stay sutures (end-to-side technique) of 7-0 polypropylene and an everting laser seal at a power level of 65 mW. The 1-year overall patency rate was 98% (78/80) in laser anastomoses, 79% (63/80) in suture anastomoses, and 95% (38/40) in combined end-to-end and end-to-side laser anastomoses. Microscopic findings in laser anastomoses demonstrated degeneration of collagen and protein in the adventitia and media, but much less intimal injury than in suture anastomoses, with reendothelialization beginning earlier (within 7 days after anastomosis as compared with 2 to 4 weeks). The tissue tensile strength at 1 hour was less in laser anastomoses than in suture anastomoses, but the laser anastomoses still withstood an intraluminal pressure load of 380 mm Hg. Laser anastomosis improved the microscopic and histologic appearance of the intimal layer, allowing for rapid early reendothelialization and resulting in excellent patency rates.

Surgery for mitral regurgitation associated with ischemic heart disease. Results and strategies.

Analysis of published reports indicates that ischemic mitral insufficiency is associated with higher operative mortality (10-30%) than is nonischemic mitral valve procedures. Probable incremental risk factors include emergency operation, acute myocardial infarction, hemodynamic instability, poor left ventricular function, pulmonary hypertension, advanced age, and renal failure. Early valve repair or replacement with myocardial revascularization improves survival in patients with circulatory insufficiency due to acute postinfarction mitral regurgitation. Although the technique of repair of nonacute ischemic mitral insufficiency is not standardized, repair with revascularization is preferred. Preliminary data suggest that long-term results are primarily related to the severity of left ventricular dysfunction.

Mechanical support for postcardiotomy heart failure.

Cardiac failure remains a life-threatening complication for certain patients undergoing intracardiac repair. Despite improvements in surgical techniques, methods of myocardial protection, and postoperative care, patients are frequently at risk to develop postoperative low output syndrome. Approximately 1% of cardiac surgical patients cannot be weaned from extracorporeal circulation in spite of adequate volume loading, the use of inotropic support, and initiation of intraaortic balloon pumping. In these cases, ventricular assist devices (VAD) can mechanically aid the failing heart and reverse the low output state. The concept of mechanical support for the failing left ventricle was first proposed by Clauss et al. in 1961. By 1968, Kantrowitz and associates had developed and refined the first intraaortic balloon pump (IABP). Through the efforts of Moulopolous and others, this device evolved into the present-day intraaortic balloon pump (IABP). Clinical evidence for the efficacy of left ventricular assist devices (LVAD) remained questionable until 1980, when the National Heart, Blood and Lung Institute evaluated short-term LVADs by comparing various types of mechanical aids. This report focused attention primarily on the failing left ventricle (LV). As the use of inotropic support, intraaortic balloon pumping, and LVADs improved, a small group of patients emerged who could not be separated from extracorporeal circulation due to a failing right ventricle. The failing right ventricle emerged as a unique clinical entity similar to postcardiotomy left ventricular failure that also benefited from mechanical cardiac assistance. Current therapy at major centers incorporating mechanical assist devices is based on the premise that the low output state will allow the failing heart to recover from a reversible injury. The frequent occurrence of postcardiotomy ischemia may be due to several factors such as poor myocardial protection, overdistension of the LV, emboli, coronary spasm or technical problems. Whatever the etiology, the end product of cardiac failure is a demand for oxygen consumption that cannot be met, thus leading to cardiac demise.

Reperfusion of skeletal muscle after warm ischemia.

The effect of 2 to 10 hours of tourniquet ischemia on the microcirculation of the tenuissimus muscle in 29 cats was studied by in vivo microscopy and electron microscopy. After release of the tourniquet there was immediate reperfusion and hyperemia in all muscles. Arterioles of 20 micron increased in diameter by 50% and venules of 35 micron by 30%. If the ischemia had lasted for 8 hours or more, reocclusion of flow occurred after 3 to 55 minutes. Platelet thromboembolism, sticking of leukocytes, and red cell aggregation seem to cause the occlusion.

The microvascular response of the neonatal mesentery to hypertonic feedings.

Using intravital microscopy we studied the responses of the jejunal and ileal mesenteric microcirculation to hypertonic meals in neonatal piglets. Test meals were infused through a cannulated segment of proximal jejunum. The intestinal segments were observed under conditions of controlled temperature and humidity, and the velocity of red blood cells through mesenteric arterioles was measured and blood flow calculated. Jejunal flow was not altered from baseline by saline or hypertonic mannitol infusion, while significant increases in flow were observed during hypertonic glucose infusion (3.8 X 10(-6) versus 10.7 X 10(-6) ml/s, p less than 0.01). Jejunal glucose infusion did not cause shunting from the ileal microcirculatory bed. We conclude that the infusion of hypertonic glucose causes an increase in jejunal blood flow, but does not result in a change in ileal flow. The increase in flow is a local phenomenon related to glucose absorption in neonatal piglets.

Partial anomalous pulmonary venous return: a ten-year experience.

In this report, 24 patients with partial anomalous pulmonary venous return were reviewed. Six of the eight patients with left-sided drainage were repaired without extracorporeal circulation by anastomosing the left-sided vein to the left atrium. Symptoms resolved in five of the six. Two of the eight were surgically repaired by using extracorporeal circulation, one of whom died in the operating room from complicated associated anomalies. Of the 16 patients with right-sided partial anomalous pulmonary venous return, all were repaired by using extracorporeal circulation and by placing a Dacron or pericardial patch to direct the venous drainage into the left atrium. Eight of these patients were restudied and had post-repair QP/QS of 1.0. Repair of partial anomalous pulmonary venous return can be accomplished with minimal morbidity and a low mortality-both of which are often related to associated anomalies.

Evaluation of fibrin sealing for cardiovascular surgery.

Hemorrhage remains a problem in patients undergoing cardiovascular surgery. To evaluate fibrin sealant, a completely biodegradable hemostatic agent, three series of experiments were performed in mongrel dogs. In series I, 18 dogs had a 7 cm interposition of knitted Dacron (water porosity 1500 ml/min/cm2) in the descending aorta. In group A, all prostheses were treated with fibrin sealant and in group B by blood preclotting. Measurements of blood loss demonstrated 1.29 +/- 0.26 ml/min in group A as compared with 30.16 +/- 2.85 ml/min in group B (p less than .001). In series II, six dogs of each group were compared for thrombogenicity and platelet survival by using indium-111-labeled autologous platelets. According to Goldman et al., the thrombogenicity index was calculated. The mean thrombogenicity index for group A was 0.23 +/- 0.02 in contrast to 0.33 +/- 0.05 for group B (p greater than .05). Mean platelet survival was 5.59 +/- 0.23 days in group A in contrast to 5.34 +/- 0.05 days in group B (p greater than .05). In series III, the gluing potential was investigated by creating four types of injuries: four dogs had an aortic stab wound 3 to 5 mm, six dogs received a 10 to 15 mm stab wound to the left ventricle, seven dogs had a 3 cm laceration of the left atrial appendage, and four dogs had bilateral division of their carotid arteries. Wounds of the aorta and left atrial appendage were treated by partial clamping and the sole use of fibrin sealant, the carotid arteries were repaired by four simple sutures and fibrin sealant, and the left ventricular stab wounds were treated by the combined use of heterologous collagen and fibrin sealant without suture.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrophysiologic abnormalities of children with ostium secundum atrial septal defect.

Sinus node (SN) and atrioventricular node (AVN) function were evaluated in 49 patients with secundum type atrial septal defect (ASD). Automaticity and conduction system function were assessed by intracardiac recording of the AH and HV intervals at rest, corrected SN recovery time, sinoatrial conduction time, AVN refractory period and the ability of the AVN to conduct rapidly paced atrial beats to the ventricles. Electrophysiologic abnormalities were found in 41% of the 34 patients who were studied before surgery. However, no preoperative abnormalities were present in children younger than 2.5 years. If only children older than 2.5 years were analyzed, the incidence of conduction abnormalities was similar for the patients studied before operation (62%) and those studied after operation (71%). The size and ejection fractions of the right and left ventricles, the magnitude of shunt flow and the size of the ASD did not differ between the patients with and those without electrophysiologic abnormalities. AVN dysfunction was present in 40% of the patients who were studied after surgical repair. While this frequency was more than twice the preoperative incidence of AVN dysfunction, it was not statistically significant. The data suggest that patient age is the major factor that influences the presence of conduction system dysfunction in patients with ASD.

Combined application of heterologous collagen and fibrin sealant for liver injuries.

Hemostasis in complex liver injuries remains a problem despite improvements in operative techniques including debridement, suturing or packing. To evaluate fibrin sealant (FS), a new biodegradable hemostatic agent in combination with porcine collagen for sealing of liver injuries, three series of experiments were performed in 132 rats. In series I, 18 rats had a 10-mm in diameter and 2-mm in depth punch defect to the left lateral lobe. In the FS group (n = 9), bleeding was treated by insertion of an FS-soaked piece of collagen of equal size which was firmly attached to a plastic disk with wire anchor. In the control group (n = 9), collagen alone was inserted. Fifteen minutes after the insertion the lobe was excised and pull-off experiments were performed with simultaneous script chart recording. There was a highly significant difference in the adhesion to the liver surface (85.6 +/- 7.1 in the FS group versus 24.8 +/- 2.6 g/cm2 in the control group, P less than 0.001). In series II, 42 anticoagulated rats (Coumadin, PT 27.5% +/- 1.3) with lobectomy or liver rupture were placed in three groups (n = 14). Group I was treated with FS, group II with FS and collagen, and group III with catgut sutures which served as controls. Fourteen days later 12 rats of group I, 13 of group II, and 7 of group III were alive yielding 85.7, 92.8, and 50% overall survival rates, P less than 0.05 groups I and II versus group III. In series III, 72 non-anticoagulated rats were treated identically to series II and examined morphologically at 1, 7, 28, and 56 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of fibrin sealant for reinforcing arterial anastomoses.

Despite improvements in needles, sutures, and technique, hemorrhage remains a problem in cardiovascular surgery. In this study conventional vascular suture lines and suture lines reinforced with fibrin sealant are compared for blood loss and burst strength. Bilateral femoral arteries in 20 dogs were divided at 50% of their circumference and repaired with six 6-0 polypropylene sutures. Ten animals were systemically heparinized (3 mg/kg), and 10 were not on anticoagulants. The right femoral artery anastomosis was treated with fibrin sealant in all animals, and the left suture line served as the control. Three minutes after initiation of the sealing procedure, blood flow was reinstituted in both femoral arteries. After 3 minutes a significant difference in blood loss between the conventional suture technique and fibrin-reinforced anastomoses was noted in both heparinized (12.1 +/- 2.79 vs. 0.13 +/- 0.06 ml/min; p less than 0.01) and nonheparinized dogs (8.45 +/- 1.37 vs. 0.20 +/- 0.08 ml/min; p less than 0.001). After 30 minutes volume inflow and pressure catheters were inserted into snared compartments encompassing the femoral artery anastomosis. Continuous pressure recordings during volume loading with normal saline solution demonstrated increased bursting pressures of the fibrin-sealed suture lines in both the heparinized (317.5 +/- 13.18 vs. 135 +/- 23.17 mm Hg; p less than 0.001) and nonheparinized animals (474.5 +/- 26.82 vs. 311 +/- 29.31 mm Hg; p less than 0.001). Histologic examination revealed no fibrosis or foreign body reaction and complete resorption of the fibrin sealant within 3 weeks. Fibrin sealant, a powerful hemostatic agent produced from human donors not suffering from hepatitis, decreases blood loss and strengthens suture lines.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular responses to PEEP and CPAP following repair of complicated congenital heart defects.

Fourteen infants and children ranging in age from 7 months to 8 years were studied in a hemodynamically stable condition following repair of various heart defects. Changes in cardiac index, stroke index, heart rate, systemic vascular resistance, mean arterial pressure, and central venous pressure were evaluated at levels of 0, 5, and 10 cm H2O using positive end-expiratory pressure (PEEP) in 14 patients and continuous positive airway pressure (CPAP) in 3 patients. No significant changes were found in any of the measurements taken at the different levels.

Spectrum of pulmonary sequestration: association with anomalous pulmonary venous drainage in infants.

Pulmonary sequestration is a spectrum of related lesions, each of which may be absent or present: (1) bronchial sequestration of pulmonary parenchyma; (2) arterial supply from systemic circulation; (3) anomalous pulmonary venous drainage to the right atrium; (4) communications between bronchus and esophagus; (5) defects of diaphragm; (6) gross lung anomalies, such as horseshoe lungs or hypoplasia. Any combination of these primary lesions can occur in an individual patient. Diagnosis should be directed towards each component of the spectrum. Of special importance is the venous connection, as anomalous pulmonary venous drainage can involve not only the sequestered segment but the entire ipsilateral lung, making surgical therapy far more complex. Treatment of choice is surgical resection, associated, if needed, with rerouting of the pulmonary venous return. Classification of sequestration of the lung as intra- and extralobar is of secondary importance: these 2 groups do not represent lesions of different embryological significance.