Thomas N. Masters

Technical Considerations in the Surgical Management of Pectus Excavatum and Carinatum

Abstract During the past 25 years, 650 operations have been performed on 608 patients for anatomically significant pectus excavatum or carinatum deformities of the anterior chest wall. There were no deaths in this series, and serious complications were very rare. We conclude that repair of pectus excavatum and carinatum deformities should include the following operative steps: (1) adequate mobilization of the sternum and correction of its abnormal angulation by transverse osteotomy; (2) adequate bilateral removal of the involved costal cartilage; and (3) securing the corrected position of the sternum with the patients own living tissue, retaining its blood supply and using it as an internal support. Using these principles, new surgical procedures were developed for the correction of: symmetrical pectus excavatum, asymmetrical pectus excavatum, pectus carinatum with xiphoid angulation, pectus carinatum without xiphoid angulation, asymmetrical pectus carinatum, chondromanubrial prominence with chondrogladiolar depression, and recurrent pectus excavatum. We recommend surgical correction for patients in whom the deformity is significant and no contraindication exists. The ill effects of this condition should not be underestimated.

Beneficial metabolic effects of methylprednisolone sodium succinate in acute myocardial ischemia.

The metabolic and hemodynamic effects of methylprednisolone sodium succinate (40 mg/kg body weight) after acute myocardial ischemia were determined in 24 heparinized mongrel dogs. Myocardial ischemia was produced by ligation of the left anterior descending coronary artery. Catheters in the coronary sinus and the vein draining the left anterior descending coronary arterial area were used to collect blood samples from nonischemic and ischemic myocardium. Lactate, pyruvate, glucose, free fatty acids and oxygen were measured in arterial and venous blood from ischemic and nonischemic areas before and 3, 30 and 60 minutes after myocardial ischemia in animals with (Group II) and without (Group I) steroid treatment. In both Groups I and II glucose, lactate, free fatty acids, oxygen and coronary blood flow in nonischemic areas were not significantly changed, whereas glucose uptake in ischemic areas was significantly increased with myocardial ischemia and remained elevated. In Group I lactate uptake in ischemic areas became negative after coronary arterial ligation and remained so; in Group II, it increased after 30 (70%) and 60 (111%) minutes. Free fatty acid uptake in ischemic areas was reduced after myocardial ischemia in Group I, but in Group II it increased after 30 (224%) and 60 minutes (173%), and there was a concomitant increase in oxygen uptake. Pyruvate uptake in nonischemic areas decreased after 60 minutes in Group I, whereas it was reduced after 30 (68%) and 60 minutes (513%) in Group II. The changes were similar in ischemic myocardium. There were no significant changes in hemodynamic indexes. Coronary blood flow in ischemic areas decreased in Group I after myocardial ischemia and further after 30 and 60 minutes, but in Group II it increased after 30 (82%) and 60 minutes (53%). The data indicate that administration of methylprednisolone results in improved collateral blood flow into the infarcted area and a significantly improved metabolic response of ischemic myocardium. The glucocorticoid may also have a direct benefical effect on carbohydrate metabolism and cause the increased pyruvate neccesary to maintain the generation of energy-producing substrates. The results also suggest that methylprednisolone increases cell survival time and results in greater salvage of ischemic myocardium.

Effects of canine donor heart preservation temperature on posttransplant left ventricular function and myocardial metabolism.

The generally accepted method of preserving donor heart integrity during transfer is to arrest it with cold cardioplegic solution, then store it in a plastic bag immersed in an iced electrolyte solution12345. Temperatures between 0°C and 4°C are maintained by this method until the heart is transplanted. Although profound hyperthermia best inhibits metabolic processes, it may damage the myocardium. Higher myocardial temperatures may be more advantageous and may result in better preservation. The efficacy of this hypothesis has been investigated in a canine model. The hearts of 40 dogs were isolated, arrested with cold cardioplegia, removed from the animal, and stored at different temperature ranges from 0–3°C to 12–15°C for 4 hr. After this time period, the hearts were transplanted into a recipient animal in the cervical heterotopic position. The degree and speed of myocardial functional recovery were monitored by measuring end-systolic elastance generated from pressure-diameter loops using sonomicrometry techniques. Myocardial metabolism was studied simultaneously by monitoring coronary flow, O2, glucose, lactate, pyruvate, and free fatty acid uptakes. The results were compared with those from a control group of hearts transplanted immediately after their removal. Our results indicate that donor heart function was significantly depressed 30 min after heterotopic transplantation, but returned to “control” levels after 2 hr when stored between 0°C and 6°C. Myocardial function remained significantly depressed throughout the 2-hr recovery period in hearts stored at higher (6–15°C) temperatures. Hearts stored at all temperatures continued to extract glucose, lactate, and free fatty acids, but produced significantly higher levels of pyruvate at higher storage temperatures, which may be related to the favored use of free fatty acids. In conclusion, donor hearts stored at colder temperatures for 4 hr regain complete left ventricular function faster than hearts stored at higher temperatures. Our experiments support the presently applied methods of donor heart preservation for 4 hr.

Can AIDS Be Prevented After Injury With Contaminated Instruments

Particulate matter comparable in size with that of human immunodeficiency virus was subcutaneously injected into experimental animals. Such matter remained at the inoculation site long enough to suggest the possibility that human immunodeficiency virus can be destroyed in loco before it invades the hosts circulation. These findings may be useful in developing a method to prevent acquired immunodeficiency syndrome after accidental injury with human immunodeficiency virus-contaminated instruments.

Experimental observations of coronary blood flow using the thermographic camera.

From the Department of Thoracic and Cardiovascular Surgery and the Department of Cardiology, Charlotte Memorial Hospital, Charlotte, North Carolina, and from the Department of Cardiology, University Medical School of Hannover, German Federal Republic. This work was supported with grants from the Heineman Medical Research Center of Charlotte and from the Minna-James-Heineman Stiftung of Germany. At the turn of the century, Sir William Herschel showed that the beam of light split through a prism generates both heat and electromagnetic radiation which is strongest beyond the red end of the visible spectrum. Further studies demonstrated that this infrared band is fairly wide, that the amount of radiation emitted is proportional to the generated heat, and that it is regulated by the same laws that govern the course and behavior of other electromagnetic waves. These observations gave birth to a new branch of physical science: thermography. The word thermography denotes pictorial recording of temperature. It should not be confused with direct infrared photography taken with an ordinary

A New Self-Anchoring Endocardial Electrode

We describe a new electrode which uses the self-anchoring property of an ejectable dart to remain in permanent contact with the right ventricular myocardium. In longrange animal experiments, there were neither disloca tions nor mechanical failures. Both acute and chronic threshold measure ments, as well as sensing characteristics, remained acceptable. The experi mental lead was applied in a clinical case refractory to treatment by other electrodes. The application of this dart-electrode appears to be indicated when elec trode instability occurs. Further well-controlled clinical trials appear to be necessary before it could be recommended for routine clinical use for all patients requiring transvenous pacemaker implants.

Simple Method to Stabilize the Blood Pressure in the Aortic Arch During Distal Crossclamping. An Experimental Study

A method is presented to stabilize the blood pressure on the aortic arch during crossclamping. The procedure consists of inserting a cannula into the proximal aorta and connecting it to a plastic buffer-bag suspended above the operating table at a level corresponding to the desired blood pressure in the aortic arch. Experimentally the method proved to be highly effective to protect the heart from acute hypertension and from overdistention injury regardless of the level of aortic crossclamping.

Invited Lecture Beneficial Effects of Computer-Controlled Blood Infusion in Patients Recovering from Cardiac Surgery

Postoperative management of cardiac surgical patients via computerized intensive care monitoring algorithms has been found to be a very valuable and useful application in medicine (1–18). Patients are admitted to the cardiovascular recovery unit immediately postoperatively, connected to the computer system, and monitored until all the recorded parameters have stabilized. All pertinent pressures, fluid loss and gain, respiratory parameters, temperature, and various objective (X-ray findings, ECG changes, patient appearance) inputs are entered into the computer system either by direct monitoring input or manual input. The information is stored and permanently maintained on the patient’s record following high speed printouts at various timed intervals during the patient’s stay.