H. Newland Oldham

Primary Cysts and Neoplasms of the Mediastinum: Recent Changes in Clinical Presentation, Methods of Diagnosis, Management, and Results

Major changes have recently occurred in the clinical presentation, diagnosis, and management of primary lesions of the mediastinum. New diagnostic techniques and improved therapy have led to more objective preoperative diagnoses as well as better long-term results. These features are clearly demonstrated in a series of 400 consecutive patients with primary lesions of the mediastinum seen at Duke University Medical Center. Of these, 99 (25%) had a primary cystic lesion. The primary tumors included thymic neoplasms (17%), neurogenic tumors (14%), lymphoma (16%), germ cell tumors (11%), and a miscellaneous group. Malignant neoplasms were present in 166 patients (42%). The anterosuperior mediastinum was the most commonly involved site of a primary cyst or neoplasm (54%), followed by the posterior mediastinum (26%) and the middle mediastinum (20%). Symptoms were present in 62% of the patients and included chest pain (30%), dyspnea (16%), fever and chills (20%), and cough (16%). Of the lesions found on routine chest roentgenograms, 83% were benign. In contrast, 57% of the lesions in symptomatic patients were malignant. Prior to 1967, 94% of asymptomatic lesions were benign, but this figure has now decreased to 76%. Fifty percent of symptomatic patients had a malignant neoplasm before 1967 compared with 62% after that year. Newer diagnostic techniques have greatly enhanced the accuracy of the preoperative diagnosis. They include radioisotopic scanning, monoclonal antibodies, hormonal assay, electron microscopy, fine-needle aspiration biopsy, computed tomographic scans, and magnetic resonance imaging. Each has a definite role and is specifically illustrated as being quite important in this series.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical management of congenital coronary artery fistulas.

Congenital fistulas are the most common of the coronary arterial malformations and with the widespread use of selective coronary arteriography are being recognized with increasing frequency. Twenty-eight patients with congenital coronary fistulas have been evaluated at the Duke University Medical Center between 1960 and 1981. An additional 258 patients have previously been reported in the literature, making a total of 286 available for review. The right coronary artery is most commonly involved, and the fistulous communication is most often to the right ventricle, right atrium or pulmonary artery. Slightly more than half of the patients with coronary fistulas are symptomatic at the time the diagnosis is made. Surgical correction is strongly recommended to prevent the development of congestive heart failure, angina, subacute bacterial endocarditis, myocardial infarction, and pulmonary hypertension, as well as coronary aneurysm formation, with subsequent rupture or embolization. There were no operative or late deaths in the patients who underwent operations. Moreover, there have been no recurrent fistulas during a mean follow-up period of ten years. The risks of operative correction appear to be considerably less than the potential for development of serious and potentially fatal complications, even in asymptomatic patients

Surgical management of chronic pulmonary embolism.

The clinical course of most patients with pulmonary embolism is one of gradual resolution with re-establishment of flow in the pulmonary arteries. In a small but definite group of patients, the emboli do not resolve and a state of chronic pulmonary embolism ensues. The primary thrombotic process in the systemic venous system may persist, and in some instances may be unrecognized. Such patients experience recurrent showers of emboll which may ultimately occlude a large part of the pulmonary arterial circulation with development of severe respiratory insufficiency. Six patients with this syndrome are described, and in each there was a history of dyspnea, cyanosis, and exercise intolerance associated with a low arterial Po2, right ventricular hypertrophy, and pulmonary hypertension. Pulmonary scans and arteriograms demonstrated that more that half of the major pulmonary arteries were occluded and, in addition, smaller vessels were also obstructed. Pulmonary embolectomy was performed in each patient. Five of the 6 obtained a highly gratifying response, including relief of the dyspnea and cyanosis, an increase in arterial Po2, and a decrease in pulmonary arterial pressure. In each of the five in whom improvement occurred, the back-bleeding from the pulmonary artery at the time of embolectomy was quite good. In the sixth patient, the back-bleeding was very poor, and despite embolectomy, the vessel thrombosed postoperatively with no improvement in the patients clinical course. Follow-up studies in these patients range up to 8 years with demonstration of continued patency of the pulmonary arteries as well as continued improvement in clinical symptoms and in the arterial Po2.

Surgical Management of Congenital Coronary Artery Fistula

Abstract Twelve patients with congenital coronary artery fistula are reported. Angina, heart failure, cardiomegaly, and electrocardiographic abnormalities were frequent findings. All patients had the fistula demonstrated angiographically, and the flow through the fistula in 8 patients produced an average pulmonary-to-systemic flow ratio of 2.2 to 1. Eleven patients had surgical closure of the fistula, and all survived with no evidence of subsequent myocardial ischemia. Relief of symptoms, reduction in heart size, and improvement in the electrocardiogram were documented postoperatively. Catheterization of a patient two years following obliteration of the fistula demonstrated normal size and function of a previously massively dilated coronary artery. The relief of symptoms, correction of hemodynamic abnormalities, low operative mortality, and threat of serious complications all emphasize the importance of surgical correction of this condition.

Ventricular aneurysm with ventricular tachycardia: Report of a case with epicardial mapping and successful resection

A case of ventricular aneurysm with refractory ventricular tachycardia is presented. Epicardial mapping was used to localize the site of earliest epicardial activity to the margin of the aneurysm, and subsequent resection of this area abolished the rhythm disturbance.

Augmentation and Redistribution of Myocardial Blood Flow During Acute Ischemia by Intraaortic Balloon Pumping

Abstract Regional coronary blood flow (CBF) in the acutely ischemic, normotensive ventricle was evaluated using radionuclide-labeled microspheres. Intraaortic balloon pumping (IABP) significantly increased CBF to myocardium made ischemic by either total or partial coronary artery occlusion. Both subendocardial and myocardial CBF in the ischemic area were increased by IABP, associated with a slight but not significant decrease in CBF to normally perfused areas of myocardium. The heart in this setting appears to autoregulate local CBF in response to IABP.

Studies of Blood Flow in Aorta-to-Coronary Venous Bypass Grafts in Man

Pressure-flow measurements were obtained from the vein graft of 57 patients undergoing a single aorta-to-coronary bypass procedure. The flow contour was similar to phasic left coronary artery flow in dogs except for a transient increase during systole possibly related to elongation of the graft. Flow was highest during bypass and decreased to a stable value 30 min after bypass. In 42 patients, flow at this time was 35+/-2 cm(3)/min (mean+/-sem).NO CORRELATIONS WERE DEMONSTRATED BETWEEN FLOW AND THE FOLLOWING: left vs. right grafts, presence or absence of collaterals, total vs. partial block, or the presence or absence of ventricular dyskinesis. In 32 patients, no correlation between these anatomic findings and the presence of reactive hyperemia was demonstrated. In 17 patients, occlusion of the graft for 10 sec resulted in a mean 51.5% flow debt repayment. In nine patients, injection of 0.3 mug of isoproterenol into the graft increased flow from 45+/-6 to 69+/-9 cm(3)/min within 4-7 sec without changes in rate, pressure, time derivative of left ventricular pressure (LV dp/dt), or left ventricular end diastolic pressure (LVEDP). Maximum increases to 87+/-10 cm(3)/min occurred 12-20 sec after injection with concomitant changes in these parameters. Intravenous infusion of norepinephrine did not change vascular resistance, whereas phenylephrine did. In six patients, injection of 0.2 mug of norepinephrine into the graft decreased flow from 49+/-6 to 25+/-5 cm(3)/min within 5-8 sec. Intravenous infusion of 0.15 mg of nitroglycerin decreased coronary vascular resistance from 2.7+/-0.4 to 2.3+/-0.3 mm Hg/cm(3) per min. In five patients, 0.12 mg of nitroglycerin injected into the graft increased flow from 46+/-7 to 71+/-13 cm(3)/min and lasted 20-40 sec.

Mediastinal Tumors and Cysts

Abstract A review of 164 patients with primary mediastinal tumors or cysts emphasizes the importance of these lesions. The clinical and pathological behavior of the individual tumors comprises a wide variety of patterns. Proper utilization of the many diagnostic tests available can accurately characterize the tumor. The exact histological diagnosis, however, is rarely made prior to operation. One-third of these tumors are malignant. For this reason and because the benign lesions often produce significant symptoms, it is recommended that all patients with a tumor or cyst of the mediastinum have excision or biopsy of the lesion, with appropriate chemotherapy or irradiation when indicated. The relief of symptoms in patients with benign lesions and the survival rate in patients with malignant lesions in our series justify this approach.

Recognition of Postoperative Acute Myocardial Infarction Application of Isoenzyme Techniques

Routine enzymatic and electrocardiographic diagnosis of postoperative acute myocardial infarction (AMI) is frequently inconclusive. The detection and quantitation of isoenzymes of lactate dehydrogenase (LDH) and creatine phosphokinase (CPK), especially the cardiac-specific CPK-MB isoenzyme, have allowed earlier recognition of AMI in nonsurgical patients. Serial monitoring with these methods has been utilized during the postoperative period in 20 noncardiac surgical patients and 100 patients undergoing coronary artery bypass grafting (CABG).In the noncardiac surgery group, both isoenzymes were accurate in diagnosing AMI in the early postoperative period. Of the 100 patients in the CABG group, CPK-MB appearance in 21 correlated with AMI by electrocardiogram. The absence of CPK-MB postoperatively in 49 patients permitted a 73% incidence of new ECG abnormalities to be effectively resolved. Autopsy confirmation of AMI was obtained in two patients with nondiagnostic ECG, but with elevated CPK-MB. The elevated CPK-MB without ECG evidence of AMI in the remaining patients could possibly be explained by varying degrees of myocardial damage produced by intraoperative cardiac manipulation. These data demonstrate the value and sensitivity of CPK-MB isoenzyme determinations in the early recognition of postoperative acute myocardial infarction.

Aortocoronary Bypass Surgery: Correlation of Angiographic, Symptomatic and Functional Improvement at 1 Year

Angiographic changes in the coronary circulation were evaluated in 60 patients 1 year after aortocoronary bypass surgery, and their relation to the postoperative clinical status was examined. Of 124 grafts implanted, 26 were closed, 7 stenotic and 91 (74 percent) patent at 1 year. Progression of occlusive disease occurred in 21 of 57 (37 percent) nongrafted and 78 of 123 (63 percent) grafted vessels. On the basis of location and severity of progression, significant lesions bypassed and patency of grafts, postoperative coronary perfusion was considered optimal in 16 patients (Group I), better in 24 (Group III). Complete freedom from chest pain or lessening of pain (improvement by two New York Heart Association functional classes) occurred in 88 and 79 percent of patients in Group III. Positive preoperative treadmill stress tests became negative after surgery in five of six patients in Group I, five of eight in Grojp II and three of eight in Group III. This study demonstrates that when progression of disease, graft patency and extent of revasculariztion are considered in combination, the postoperative angiographic status of the coronary circulation correlates well with clinical improvement at 1 year. These findings support the hypothesis that improved blood supply to ischemic myocardium is a major factor contributing to relief of angina pectoris after saphenous vein bypass surgery.