David R. Jones

Biatrial approach to cardiac myxomas: A 30-year clinical experience

Early surgical intervention for atrial myxomas mitigates morbidity and usually offers cure. The operative approach to resect these tumors is controversial. The purpose of this study was to review our experience with the biatrial approach between 1964 and 1994. The location of the myxoma was left atrium in 17 and right atrium in 3. Mean preoperative New York Heart Association functional classification was 2.7. Surgical approach to the tumor was biatrial in all patients. There were no perioperative strokes, myocardial infarctions, or deaths. Mean follow-up was 7.5 years (range, 2 mo to 27 years) with a postoperative New York Heart Association functional classification of 1.4. One late death occurred, which was unrelated to the myxoma. Advantages of biatrial approach include (1) definition of tumor pedicle by direct visualization, (2) minimal manipulation of the tumor, (3) adequate margins of excision, (4) inspection of all heart chambers, and (5) secure closure of the atrial septal defect. Long-term follow-up demonstrates the efficacy of this operative approach to atrial myxomas.

Effects of insufflation on hemodynamics during thoracoscopy

Thoracic procedures once requiring open thoracotomy are now being performed with video-assisted thoracoscopy. To visualize adequately the intrathoracic structures, creation of an artificial pneumothorax by carbon dioxide insufflation under positive pressures has been advocated. We hypothesized that positive-pressure insufflation during thorascopy would cause significant hemodynamic compromise. Eight healthy female pigs underwent general endotracheal anesthesia and placement of monitoring lines. After placement of a thorascope, baseline hemodynamic measurements were obtained at 0 mm Hg (atmospheric pressure). Measurements were taken randomly at 5, 10, and 15 mm Hg using carbon dioxide insufflation after stabilization at each pressure. Data were analyzed using Pages test for noparametric variables. Insufflation pressures of 5 mm Hg or greater resulted in significant decreases in cardiac index, mean arterial pressure, stroke volume, and left ventricular stroke work index, whereas central venous pressure increased (p < 0.001). Changes in heart rate were not significant. We do not recommend routine positive-pressure insufflation during thorascopy because of the significant hemodynamic compromise in our experimental model.

Potential application of p53 as an intermediate biomarker in Barrett's esophagus

Diagnosis of the neoplastic progression in Barretts esophagus using the histologic classification of dysplasia is frequently difficult. The tumor suppressor protein p53, when mutated, confers a promoter effect on cell growth. The purpose of this study was to evaluate the applicability of p53 as an intermediate biomarker of malignancy in Barretts esophagus. Archival analysis of 100 biopsy specimens of Barretts esophagus and 10 esophageal adenocarcinomas were compared with 35 chronic esophagitis biopsy specimens. Immunocytochemistry using an anti-p53 monoclonal antibody was performed and elevated immunoreactivity quantitated microscopically. Data were analyzed using a logistic regression model. Significant p53 immunoreactivity occurred as follows: chronic esophagitis (0%), Barretts esophagus without dysplasia (10%), with low-grade dysplasia (60%), with high-grade dysplasia (100%), and adenocarcinoma (70%). All cases of Barretts esophagus were significantly immunoreactive when compared with the chronic esophagitis cases (p = 0.001). There was an increase in p53 immunoreactivity as the histologic classification progressed toward adenocarcinoma (p = 0.001). Progression to high-grade dysplasia may be predicted based on p53 immunoreactivity. These findings suggest a role for p53 as an intermediate biomarker in Barretts esophagus.

Selective lung ventilation during thoracoscopy: Effects of insufflation on hemodynamics

BACKGROUNDnPositive-pressure insufflation during thoracoscopy has been advocated by some authors to facilitate exposure of the intrathoracic structures by expediting collapse of the lung. We hypothesized that insufflation during thoracoscopy may result in hemodynamic compromise despite selective lung ventilation.nnnMETHODSnAfter placement of invasive monitoring lines, six adult swine underwent selective lung ventilation and thoracoscopy. Baseline measurements of hemodynamic indices were taken before selective lung ventilation. The right lung then was collapsed; data were obtained at insufflation pressures up to 10 mm Hg and were compared with baseline values using Students t test.nnnRESULTSnCardiac index, mean arterial pressure, and left ventricular stroke work index decreased, whereas pulmonary artery and central venous pressures increased (p < 0.05) at insufflation pressures of 5 mm Hg and greater.nnnCONCLUSIONSnPositive-pressure insufflation during thoracoscopy resulted in significant hemodynamic compromise despite the use of selective lung ventilation. Conversion to thoracotomy may be an alternative if positive-pressure insufflation is necessary to perform the thoracoscopic procedure.

The role of thoracoscopy in thoracic trauma

The advent of video-assisted thoracic surgical procedures has caused many thoracic surgeons to reevaluate their approach to the management of diseases of the chest. The management of traumatic thoracic injuries is an area in which thoracoscopic techniques may have significant impact. The current role of thoracoscopy in the diagnosis and therapy of thoracic trauma continues to evolve. This review considers the currently accepted diagnostic and therapeutic applications of thoracoscopy in the management of these patients. The technique of thoracoscopy as it applies to the trauma patient is also discussed, as well as the future and expanding applications of thoracoscopy in this setting.

Use of heparin-coated cardiopulmonary bypass

A 49-year-old man with unstable angina and a history of severe anaphylaxis to seafood and intravenous iodine needed myocardial revascularization. Because of concern of an intraoperative protamine reaction, preoperative treatment was instituted with steroids and with H1 and H2 blockers. Revascularization was accomplished using a heparin-coated cardiopulmonary bypass circuit. Complement activation and postoperative bleeding were minimal. Heparin-coated cardiopulmonary bypass is a safe, effective technique of bypass in select patients.

Safe use of heparin-coated bypass circuits incorporating a pump-oxygenator

Durable, covalently bonded, heparin-coated cardiopulmonary bypass (CPB) circuits with oxygenators have been developed. Proposed advantages of heparin-coated CPB circuits include improved biocompatibility and thromboresistance. The purpose of this study was to evaluate our experience with heparin-coated CPB circuits in 20 patients. Heparin was given to maintain an activated clotting time equal to or greater than 200 seconds, while flow rates were kept equal to or greater than 2 L/min. Indications for use of this circuit included recent stroke, posttraumatic injuries, recent gastrointestinal bleeding, protamine allergies, combined cardiac and noncardiac procedures, and ventricular assist. Mean heparin dosage was 0.50 +/- 0.18 mg/kg and protamine dosage was 57.14 +/- 39.36 mg. Postoperative blood loss and transfusion requirements were minimal. Postoperative complement levels of C3a and C5a were normal, suggesting excellent biocompatibility. There were no deaths or perioperative complications. Heparin-coated CPB circuits using a pump oxygenator can be used safely with low-dose heparin administration in select patients requiring CPB.

Unusual location of an atrial myxoma complicated by a secundum atrial septal defect.

Myxomas occur most commonly in the left atrium arising from the fossa ovalis. We report the case of a left atrial myxoma originating from the base of the right inferior pulmonary vein. This large myxoma filled a large secundum atrial septal defect, which was diagnosed intraoperatively. The unusual position of this myxoma and operative management of the associated atrial septal defect are discussed.

Coronary-Subclavian Steal with Concomitant Carotid Disease: Indication for Axilloaxillary Bypass A Case Report

Coronary-subclavian steal syndrome is a potential complication of coronary artery bypass grafting when the internal mammary artery is used as a conduit. Concomitant carotid artery disease complicates the syndrome by introducing a possible simultaneous cerebral steal phenomenon. The authors present the first reported case of a patient who had symptomatic coronary-subclavian steal with significant carotid occlusive disease. An axilloaxillary bypass was performed instead of the standard carotid-subclavian bypass. Recommendations concerning the diagnosis and management of this syndrome are presented and the indication for axilloaxillary bypass is outlined.