Aberrant left pulmonary artery (pulmonary artery sling): successful repair and 24 year follow-up report.

A case of anomalous left pulmonary artery arising from the right and coursing behind the trachea and anterior to the esophagus (pulmonary artery sling) is reported. The therapy currently advocated for this disorder is ligation of the anomalous vessel and performance of a left pulmonary to main pulmonary arterial anastomosis anterior to the trachea. A median sternotomy incision allows total mobilization of the anomalous vessel, minimizes respiratory embarrassment and aids in performance of the anastomosis. In the present case, a postoperative pulmonary angiogram revealed a patent left pulmonary artery, the second reported instance of such patency. The first successful repair of pulmonary artery sling was reported by Potts and colleagues in 1954. After a 24 year follow-up period their patient has normal exercise tolerance and no perfusion to the left lung is evident on ventilation-perfusion scan.

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.

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.

Traumatic avulsion of the innominate and left carotid arteries: successful repair.

Traumatic rupture of the aorta or the arch vessels is a rare and frequently fatal injury. This lesion should be considered in all cases of severe chest trauma. Early aortography is essential for accurate diagnosis. Nineteen cases of avulsion of the innominate artery have been previously reported. In only two of them a second aortic arch branch had an associated injury. The case presented here is the first successful repair of a combined avulsion of both the innominate and the carotid arteries from the aortic arch. Cerebral circulation was maintained during the operation with a heparin-coated shunt from the ascending aorta to the right common carotid artery. Reconstruction was accomplished by inserting a bifurcated Dacron prosthesis from the aorta to the innominate and left carotid arteries. The use of a heparin-bonded shunt maintained cerebral perfusion, and greatly simplified the operation and avoided the risk of extracorporeal circulation and systemic anticoagulation in a patient with multiple trauma.

Failure of intra-aortic balloon pumping to reduce experimental myocardial infarct size in swine.

Although intra-aortic balloon pumping (IABP) is reported to reduce myocardial infarct size in dogs, this phenomenon may be due to pre-existing collaterals in this species. Pigs more closely approximate human coronary anatomy, having poor inherent collateralization. This study evaluates hemodynamic changes and quantitates myocardial infarct size 24 hours after coronary occlusion in swine, with and without IABP. Eighteen pigs underwent ligation of the left anterior descending coronary artery distal to the first diagonal branch: Nine were treated with IABP beginning 45 minutes after coronary occlusion and nine served as control subjects. Three in each group died prior to completion of the study. In both groups myocardial infarction resulted in a significant (p less than 0.05) decrease of cardiac output (28.5%) and mean aortic pressure (p less than 0.05) improvement of mean aortic pressure (4 to 7%) during the switch on period. After 24 hours, mean aortic pressure in IABP-treated animals (105 +/- 20 mm Hg) was significantly (p less than 0.01) higher than in control pigs (73 +/- 12 mm Hg). Myocardial infarct size as detected by staining with nitroblue tetrazolium was 22.7 +/- 4.9 gm infarct/100 gm left ventricular and septal mass in control pigs and 19.4 +/- 5.9 gm infarct/100 gm left ventricular and septal mass in treated animals (p less than 0.3). In conclusion, IABP, despite significantly improving circulatory parameters, does not significantly reduce the size of an acute myocardial infarction after coronary ligation in swine.

Earlier operation for left-sided Pseudomonas endocarditis in drug addicts.

Three consecutive patients with Pseudomonas endocarditis were treated by early operation with no deaths. The indications for operation were severe failure, systemic embolization, and infection refractory to antibiotics. The organism is aggressive, characterized by early invasion of the myocardium. Wide débridement of the anulus is necessary to remove any vegetations or intramyocardial abscessed wall. Because multiple valve infection is common, it is important to evaluate all four cardiac valves at the time of operation. Removing a second rim of the mitral anulus for separate culture at the time of mitral valve replacement may demonstrate the degree to which the valve resection has removed all infection. Early operation is necessary for reinfection of the prosthetic valve; however, metastatic abscess should also be considered in the face of continued signs of infection postoperatively. Patients should receive a 6 week postoperative course of antibiotics which have been shown by in vitro testing to be serum bactericidal in at least a 1:8 dilution. The operative findings of invasion of the myocardium by the organism and the surgical success in this small series have resulted in our recommending earlier operation in patients with these indications.

Effect of coronary artery reperfusion on infarct size in swine.

Several authors have reported a low mortality and salvage of ischemic myocardium in patients undergoing coronary revascularization after recent myocardial infarction. In this study, 20 surviving pigs with a coronary circulation similar to that of man were divided into two groups of 10 animals each. In the first group, the left anterior descending coronary artery (LAD) was ligated just beyond the first diagonal branch. Five animals were put to death at 24 hours and the remaining five animals, at 7 days. In the other group of 10 animals, the LAD was occluded just beyond the first diagonal branch and reperfused 3 hours after occlusion. Five of these animals were put to death at 24 hours and the remaining five animals, at 7 days. The left atrial pressure (LAP), heart rate, mean arterial pressure (MAP), and cardiac output were continuously monitored. Myocardial infarct size was determined planimetrically after the myocardium was sliced and stained with nitroblue tetrazolium. In five animals subjected to ligation for 24 hours, myocardial infarct size was 20.3 +/- 0.53 standard error mean (SEM) grams infarct per 100 gm left ventricular and septal mass (gm/100 gm LVS). In five animals subjected to occlusion, reperfusion in 3 hours, and death at 24 hours, the infarct size was 22.9 +/- 1.7 SEM gm/100 gm LVS. At 1 week in the ligated animals the infarction decreased to 15.5 +/- 1.7 SEM gm/100 gm LVS. In the reperfused animals at 1 week the infarction size was 14.5 +/- 1.7 SEM gm/100gm LVS. There was no significant difference in these values (Student's t test). Light and electron micrographs demonstrated hemorrhagic necrosis in every instance with reperfusion. Cardiac output, LAP, and MAP remained unchanged after reperfusion. These data suggest that in human beings without well-developed inherent collaterals sustaining myocardial infarction with coronary occlusion, that reperfusion as early as 3 hours after infarction would not be beneficial.

Long-term evaluation of pericardial substitutes.

The development of postoperative pericardial adhesions increases the risk of cardiac reoperations because of the danger of damaging the heart, great vessels, or grafts. Several pericardial substitutes have been tested in the past in an attempt to facilitate reoperation, with inconclusive results. This study evaluated eight different materials as pericardial substitutes: six synthetic materials and two different preparations of bovine pericardium. In 32 dogs a 10 by 5 cm piece of pericardium was excised through a right thoracotomy and the defect closed with a measured patch. Each material tested was implanted in four dogs that were put to death at 3, 6, 9, and 12 months. At autopsy the development of adhesions and epicardial reaction were graded as none, minimal, moderate, and severe. Histologic studies of the patch, the epicardium, and the suture line were performed. Our results suggest that both types of bovine pericardium were an excellent substitute. Although minimal adhesions developed, these were easily dissected. The underlying anatomy was clearly recognizable because of the lack of epicardial reaction. Silicone rubber-coated polyester fabric was an acceptable material for the prevention of adhesions, but a severe fibrous epicardial reaction impeded the recognition of the coronary arteries. Both silicone-filled and high-porosity polytetrafluoroethylene (PTFE) films reduced adhesions but caused a severe epicardial reaction. The other synthetic materials were considered inferior because of severe epicardial reaction and/or structural deterioration.

Surgical treatment of recurrent primary malignant tumor of the left atrium.

A young woman presented with a tumor in the left atrium resembling a left atrial myxoma. After simple excision of the tumor the diagnosis of primary malignant fibrous histiocytoma of the heart was made. A course of radiation therapy was given. Four subsequent recurrences were treated by cardiotomy and resection of the left atrial wall. At the third, fourth, and fifth operations fulguration of the left atrial wall was performed. Subsequent chemotherapy failed to control the tumor. The patient was admitted 6 weeks after the last resection and died. Postmortem examination revealed a large recurrent tumor obstructing the left atrium with no metastases. The clinical course, cardiac catherization data, and postmortem examination are presented. Palliation was achieved by repeated resection of a radiation-resistent primary sarcoma of the heart.

Right atrial partition and right ventricular exclusion: another surgical approach for complex cyanotic congenital heart disease.

A 5-year-old child with asplenia, situs inversus, single ventricle, common atrium, severe subvalvular pulmonary stenosis, 1-transposition of the great arteries, and absent inferior vena cava presented with severe limitation (resting arterial saturation 74 per cent). At operation, the systemic venous atrium was partitioned with a Dacron baffle, so that hepatic venous and coronary sinus blood was enabled to drain with the pulmonary venous blood into the single ventricle and aorta. The superior portion of this atrium was anastomosed to the divided main pulmonary artery, so that most of the systemic venous blood was allowed to flow directly to the lungs. Intraoperative hemodynamic studies revealed a pulmonary artery pressure of 12/9 mm. Hg and a superior vena caval flow that was 88 per cent of the ascending aortic blood flow. Follow-up catheterization studies revealed an intact partition, no anastomotic gradient, superior vena cava pressure of 20 mm. Hg, arterial saturation of 84 per cent, and excellent flow of contrast from superior vena cava to atrium to pulmonary artery. Exercise tolerance was markedly improved, and chronic fluid retention was not observed. This operation offers a new alternative for long-term palliation of complex lesions amenable to exclusion of the right ventricle, such as single or common ventricle with unreconstructable anomalies of the atrioventricular valves.

Changes in indications for heart transplantation. An additional argument for the preservation of the recipient's own heart.

The 1 year survival rate after heart transplantation since 1967 from +/-30% to +/-70%, and the 5 year survival rate is now +/-50%. This improvement has brought renewed interest in this procedure, now done in about twenty centers in eight countries, and increased confidence has widened the indication to patients who are less than terminally ill, to restore quality of life. This trend is illustrated by the Cape Town series, which can be divided into two parts: 10 patients treated by orthotopic heart transplantation (OHT), from 1967 to 1973, and 40 patients treated by heterotopic heart transplantation (HHT), from 1974 to 1981. The HHT group was younger (mean 37 +/- 10 years versus 51 +/- 9 years, p less than 0.001), had been ill for a shorter length of time (mean 3.6 +/- 0.7 years versus 6.6 +/- 1.4 years, p less than 0.091), and were in a lower New York Heart Association (NYHA) class (mean 3.45 +/- 0.11 versus 3.9 +/- 1.0, p less than 0.006). The improved survival is linked to patient selection, progress in management, and switch to HHT, but not to progress in matching between donor and recipient. Since there is no means to predict tolerance of the donor heart, HHT limits the risks from unforseeable mismatch. The recipient's heart is a built-in assist device, maintaining life when the donor heart fails acutely at operation or during acute [three cases] or chronic [two cases] rejection. Had these patients undergone OHT they would have died. Comparing the 10 oldest HHT patients with the OHT series, no difference in pretransplant parameters was found. However, survival of HHT recipients was longer during the critical post-HHT period: at 3 months, p less than 0.011; at 6 months, p less than 0.05. Larger series will separate the effects of progress in management from the intrinsic advantages of HHT. Retaining the recipient's heart is logical and has brought few complications. Survival rate of 40 HHT patients was 73% at 6, 65% at 12, and 51% at 36 months; 85% of survivors are in NYHA Class I. In patients in less than desperate condition, but who refuse to remain cripples, HHT eliminates the growing ethical problem of removing a recipient's heart that may still support the patient.

Arterial prosthesis of microporous expanded polytetrafluoroethylene for construction of aorta-pulmonary shunts.

A new arterial prosthesis made of polytetrafluoroethylene (OTFE) was evaluated in 10 infants with complex cyanotic congenital heart disease. All grafts used were 4 mm. in diameter and varied in length from 0.8 to 6 cm. The grafts were anastomosed to the main pulmonary artery or its bifurcation in 8 infants and to the right and left pulmonary arteries in one each. There were two early deaths, one of which was related to shunt failure. The advantages of a shunt to the main pulmonary artery are obvious, and the intraoperative procedure is facilitated with the prosthesis. Follow-up averages 9 months in the 8 survivors, and the patients have nearly doubled their preoperative weight. A shunt murmur is present in each case and the children have mild-to-moderate cyanosis at rest. Repeat aortograms in 2 patients, 8 and 10 months postoperatively, show a smooth graft without luminal narrowing. The aortic oxygen saturations were 73 per cent. The PTFE graft and/or anastomoses will not grow with the growth of the child and therefore may not accommodate growth by increased flow. This may prove to be a limiting factor in its long-term use in fants. We reserve the use of these grafts for infants with complex cyanotic defects undergoing emergency surgery or in older children in whom a conventional shunt is not possible or a previous shunt has failed.

Surface cooling (20 degrees C) and circulatory arrest in infants undergoing cardiac surgery. Results in ventricular septal defect, complete atrioventricular canal, and total anomalous pulmonary venous connection.

During a six-year period, 46 severely symptomatic infants (average age, 5.1 months) underwent correction of ventricular septal defect (22 patients), total anomalous pulmonary venous connection (13 patients), and complete atrioventricular canal (11 patients), with the use of surface cooling to 20 degrees C. Cardiac repair was performed during circulatory arrest, and rewarming was performed with a pump oxygenator. Ten patients undergoing repair of ventricular septal defects were studied hemodynamically at 21 degrees C, before repair and at 37 degrees C after rewarming. Heart rate, left ventricular systolic pressure, maximum dp/dt, cardiac index, stroke work, and oxygen consumption were reduced substantially at 21 degrees C. Systemic vascualr resistance was increased at 21 degrees C. All changes were reversible with repair and rewarming. A protocol for hemodilution and crystalloid volume loading was devised to maintain urine output after early patients were noted to demonstrate renal dysfunction. With this protocol, survival rates were 89% for patients with ventricular septal defects, 67% for those with atrioventricular canal defects, and 85% for those with total anomalous pulmonary-venous connection.

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).

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.

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.

Reduction of myocardial infarct size in swine: a comparative study of intraaortic balloon pumping and transapical left ventricular bypass.

This study compared intraaortic balloon pumping (IABP) and transapical left ventricular (LV) bypass for their effectiveness in reducing infarct size in swine. In 28 pigs (25.4 +/- 4.7 kg) the left anterior descending coronary artery was ligated distal to the first diagonal branch. Nine animals served as controls. Nine animals were treated with IABP and the remaining 10, with transapical bypass. Ten animals-3 control, 3 IABP, and 4 transapical bypass--died prior to completion of the study, thereby resulting in 6 animals in each group. Both assist devices were begun 45 minutes after coronary ligation, this being as rapid as mechanical intervention could be accomplished in the patient after infarction. With transapical LV bypass, 70 to 100% bypass was accomplished and the LV systolic pressure remained in the range between mean aortic pressure and 30 mm Hg less than that. All animals were killed after 24 hours. The hearts were excised and stained with nitroblue tetrazolium, and infarct size was quantitated in grams of infarct per 100 gm of LV and septal mass. After 24 hours the mean aortic pressure was 73 +/- 12 mm Hg in controls, 105 +/- 20 mm Hg in animals with IABP (p less than 0.01), and 91 +/- 13 mm Hg in those with transapical LV bypass (p less than 0.05). The infarct size was 22.7 +/- 4.9 gm per 100 gm of LV and septal mass in control animals. With IABP, the infarct size was nonsignificantly changed to 19.4 +/-5.9 gm per 100 gm (p greater than 0.3). With transapical LV bypass, the infarct size was significantly reduced to 15.9 +/- 3.5 gm per 100 gm (p less than 0.025). This represented a 30% reduction of infarct size from controls. These results demonstrate that despite hemodynamic improvement with IABP, transapical LV bypass is necessary to markedly decrease myocardial work and significantly reduce infarct size.

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.

The prosthetic (Teflon) central aortopulmonary shunt for cyanotic infants less than three weeks old: results and long-term follow-up.

The expanded microporous polytetrafluoroethylene (PTFE) 4 mm vascular prosthesis has been used to create a central aortopulmonary shunt in 20 critically ill infants less than 3 weeks old. The infants ranged from 1 to 18 days old (5.25 days), and from 1.5 to 4.0 kg (2.9 kg). Conduit length ranged from 2 to 6 cm (4 cm). Sixteen patients had atresia of the tricuspid or pulmonary valve. There were 6 early deaths (30%), only 1 of which was shunt related. The mean preoperative arterial oxygen saturation was 62% (range, 33 to 80%), and mean postoperative saturation was 87% (range, 78 to 90%). There were 5 late deaths, 1 probably caused by shunt failure. Nine long-term survivors have done well. Follow-up ranges from 1 to 36 months (18 months). Factors influencing conduit function are length, technical considerations, and pulmonary vascular resistance. Late restudy in 5 of 9 survivors confirms patency and demonstrates bidirectional pulmonary blood flow. Since PTFE shunt flow capability is fixed, the infant may require repair or a second shunt within 24 months of the initial procedure.