Aorta-to-right ventricular fistula due to pectus bar migration.

A 23-year-old man, operated on for pectus excavatum with a modified Ravitch procedure, was admitted to our emergency department suffering from severe dyspnea. Massive pericardial effusion, rupture of the sinus of Valsalva, and aortic-to-right ventricular fistula were present on echocardiography. Cardiac penetration of the metal bar was detected on chest CT scan. The defect at the right sinus of Valsalva was closed with a PTFE patch, and the right aortic and ventricular ruptures were repaired primarily.

Aspirin resistance after CABG.

BACKGROUND: Temporary aspirin resistance can occur during the post-CABG period. If the factors causing resistance can be identified, the incidence of early graft occlusions can also be minimized. METHODS: 25 elective CABG cases were enrolled in the study. The platelet count, mean platelet volume, the C-reactive protein level, lipid profile, blood urea nitrogen (BUN), and creatinine levels were identified one day before the operation and on the 1st, 5th and 10th postoperative days. Optical aggregometry was used for the evaluation of aspirin response. The patients were divided into two groups: those with aspirin resistance and those with no aspirin resistance. RESULTS: The rate of postoperative aspirin resistance was found to be 60 %. No significant difference was found when the preoperative and operative data of the two groups were compared. It was found that the rapid changes observed in the postoperative platelet counts and the C-reactive protein levels were similar. CONCLUSION: Aspirin resistance is encountered during the early postoperative period in the majority of patients undergoing CABG. None of the factors studied were found to be causative for resistance formation. Further studies are required to clarify this entity.

Coronary artery stabilization causes endothelial damage: an electron microscopic study on dogs.

In recent years, to protect patients from adverse effects of cardiopulmonary bypass, off-pump coronary artery bypass operations are performed. In these operations, effective coronary artery immobilization is the standard for a fine anastomosis. This is usually maintained with the help of prolene immobilization sutures, bulldog occluders or mechanical epicardial devices. The aim of this study is to show whether these stabilization devices cause any damage to the coronary artery endothelium. Sixteen dogs are included in this study and are divided into four groups. The control group consisted of one dog (Group I) and different immobilization techniques are applied to the other groups, which were five dogs each (Groups II, III, and IV). Coronary artery biopsies are obtained, then the samples are studied under scanning electron microscope (SEM) for endothelial injury and all samples are scored. Among the techniques used, bulldog occluders caused less injury on the coronary endothelium than the prolene sutures.

Nitroglycerin-induced hypoxemia does not produce myocardial ischemia.

OBJECTIVE: Nitroglycerin has been the drug of choice for relieving myocardial ischemia for more than a hundred years. Several studies have indicated that a significant reduction in arterial oxygen tension (PaO2) occurs after the administration of sublingual nitroglycerin to patients with coronary artery disease breathing room air. Because available oxygen in arterial blood is reduced, it would be reasonable to assume that oxygen delivery to the myocardium would also be impaired. The purpose of this study was to investigate whether nitroglycerin-induced arterial desaturation results in compromised oxidative metabolism of myocardium assessed by coronary sinus lactate concentration and oxygen content in patients with coronary artery disease undergoing coronary artery bypass surgery. PARTICIPANTS: Ten randomly selected patients undergoing coronary bypass surgery. SETTING: All studies were performed at Siyami Ersek Cardiovascular and Thoracic Surgery Center. METHODS: A catheter was inserted into the radial artery to measure blood gases and arterial lactate concentration. After sternotomy, and aortic and venous cannula placement, a coronary sinus catheter was introduced into the coronary sinus to measure oxygen content and lactate concentration. Control coronary sinus and arterial blood samples were obtained before nitroglycerin infusion. Nitroglycerin was then given in a dose of 2 micrograms/kg/min for a period of 5 minutes. At the end of 5 minutes, second samples were obtained from the coronary sinus and arterial catheters. MAIN RESULTS: It was found that arterial and coronary sinus oxygen tension decreased significantly. Arterial lactate concentration did not change, coronary sinus lactate concentration decreased. Despite a substantial fall in arterial oxygen tension after administration of nitroglycerin, a significant reduction in coronary sinus lactate concentration occurred. CONCLUSION: Nitroglycerin-induced hypoxia does not compromise oxidative metabolism of myocardium as can be assessed by a concomitant decrease in coronary sinus lactate concentration.

Effect of normothermic papaverine to relieve intraoperative spasm of the internal thoracic artery.

BACKGROUND: After mobilization, vasospasm often reduces flow through the internal thoracic artery. An established method of relaxing the artery and increasing flow is to use papaverine at ambient temperature (20 degrees to 22 degrees C) as a topical vasodilator. However, the pharmacologic actions of papaverine generally have been assessed at 37 degrees C. METHODS: In 60 patients in whom the left internal thoracic artery was used for myocardial revascularization, we investigated the effects of normal saline solution at 20 degrees C (group I), papaverine at 20 degrees C (group II), and papaverine at 37 degrees C (group III). Under controlled hemodynamic conditions, free flow was measured before any pharmacologic intervention and a median of 16 minutes after the pedicle had been sprayed with one of the agents. RESULTS: Normal saline solution at 20 degrees C produced a small increase in flow from 37.5 +/- 8.1 mL/min to 50 +/- 10.2 mL/min. A significant increase occurred with papaverine at 20 degrees C, from 38.05 +/- 6.5 mL/min to 78.75 +/- 21.2 mL/min (p < 0.0001). Papaverine at 37 degrees C, however, produced an increase in flow from 36.9 +/- 12.6 mL/min to 103.3 +/- 44.6 mL/min (p < 0.0001) and proved to be more effective than papaverine at room temperature (p = 0.0174). CONCLUSIONS: We recommend topical use of papaverine at 37 degrees C to relieve intraoperative spasm of the internal thoracic artery.

Use of color Doppler imaging in assessment of preoperative and postoperative flow characteristics of internal thoracic artery in myocardial revascularization.

Between January 1993 and February 1993, the left internal thoracic arteries of 40 consecutive patients scheduled for aortocoronary bypass operation were examined by transthoracic B-mode imaging. Perioperative measurements correlated well with preoperative noninvasive measurements (r = 0.914). In the postoperative period, B-mode images could not be obtained in 17 (44.7%) of 38 patients. Adequate Doppler spectra of the internal thoracic artery were obtained in all patients preoperatively and in 36 (94.7%) of 38 patients postoperatively. Preoperatively a triphasic wave form was obtained with a large systolic peak followed by small reversed and diastolic components in all patients. Postoperatively this triphasic wave form had been converted into a combined systolic-diastolic wave form. In all patients peak systolic velocity of the internal thoracic artery decreased (96.4 +/- 15.3 vs 64.2 +/- 18.9 cm/sec., P < 0.05), and peak diastolic velocity increased (21.7 +/- 8.8 vs 28.3 +/- 11.2 cm/sec., P < 0.05) significantly in the postoperative period as compared with the preoperative values. A slight decrease in peak systolic and diastolic velocities was detected at twelve months postoperatively. This study indicates that transthoracic B-mode imaging and Doppler spectrum analysis are reliable techniques in the preoperative and postoperative assessment of the internal thoracic artery in myocardial revascularization.