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Biomedical subjects

G Pappas

Publications and source records attributed to G Pappas.

At least 73 records · Page 4Linked to original sources
PubMed1982

Intrapericardial Blalock-Taussig shunt.

The standard Blalock-Taussig (B-T) shunt is preferred over other shunts in the treatment of infants with cyanotic heart disease and reduced pulmonary blood flow. The B-T shunt is not, however, without problems such as phrenic nerve injury and excessive bleeding. It is a time-consuming procedure owing to the degree of lateral mediastinal dissection required (the latter is especially important in critically hypoxic infants). An alternative procedure is described in which an intrapericardial approach is used. This approach requires minimal dissection of the subclavian artery and the anastomosis is performed to the pulmonary artery, medial to the superior vena cava (SVC) and lateral to the aorta. The procedure was performed on 17 infants from 1 day to 2 years of age (average age of 9.4 months, with seven of the 17 infants being less than 6 months of age). Follow-up ranged from 1 to 44 months (average of 17 months). In 94%, the shunt was functioning well. The potential advantages of this approach include: elimination of phrenic nerve injury, easy dissection with reduced operating time, reduced intraoperative hemorrhage, and perhaps a larger anastomosis with improved patency rate.

Child, Preschool↗
PubMed1981

Surgical repair of coarctation of the aorta in infants less than six months of age: including the question of pulmonary artery banding.

High mortality rates (20% to 60%) have been reported in the repair of coarctation of the aorta in infancy. During a 4 year period, 34 infants less than 6 months of age had coarctation repair (two prior to 1976). Eleven were less than 2 weeks of age, nine were 2 weeks to 1 month, eight were 1 to 2 months, and six were 2 to 6 months. Associated lesions were patent ductus arteriosus (PDA) (82%), ventricular septal defect (VSD) (53%), and other intracardiac lesions (35%). Twenty-three patients (67%) had emergency operations; the other procedures were semielective. The indications for operation included congestive cardiac failure (91%), acidosis (32%), hypertension (29%), cardiogenic shock (26%), and cardiac arrest (18%). There was one operative death (2.9%) in a patient with severe pulmonary valve insufficiency and multiple VSDs. There was one late death a 4 months (Taussig-Bing complex). Primary repair was used in 15, patch-graft angioplasty in 19 (left subclavian artery in nine, left common carotid in one, and Dacron or pericardial patch in nine). Two (6%) required reoperation for recurrent coarctation (follow-up 3 to 36 months with a mean of 25.8). Of 15 patients with a large VSD, six had pulmonary artery banding with two deaths (one operative and one late), two had debanding plus VSD repair, and two are awaiting operation. The remaining nine patients did not have banding (no operative or late deaths), four patients required late VSD closure, two VSDs closed spontaneously, two VSDs became smaller, and one patient is awaiting VSD closure. The infrequent need for pulmonary artery banding may be partly due to "physiological banding" seen at Denver's high altitude. The VSD spontaneously closed or became smaller in 44% of nonbanded patients. The low operative mortality can be ascribed to (1) aggressive medical therapy, (2) emergency catheterization and repair, (3) avoidance of hypothermia, and (4) adequate relief of the coarctation.

Aorta↗
PubMed1977

Effect of parent coronary arterial occlusion on left ventricular function after aortocoronary bypass surgery.

In 62 men with open parent coronary arteries who underwent saphenous vein aortocoronary bypass to either the right or left anterior descending coronary artery, or both, left ventricular ejection fraction and wall motion of the anterior and inferior segments of the left ventricle were measured before and after (average 11 months) the operation. Of 34 left ventricular segments with open vein grafts and open parent coronary arteries, 91 percent were unaltered by the operation, none were in worse condition and 9 percent showed improved wall movement. Among 33 segments with open grafts but new total occlusion of the parent coronary arteries, 67 percent were unaltered, whereas the condition of 18 percent was worse and of 15 percent was improved. Among 21 segments with closed grafts but patent parent arteries, the condition of 29 percent was unchanged and of 71 percent was worse; among 14 segments with occlusion of both grafts and parent arteries the condition of 29 percent was unchanged and of 71 percent was worse. In 10 men with patency of all vein grafts and parent arteries, left ventricular ejection fraction was not altered (0.55 +/- 0.03 to 0.53 +/- 0.04 [average +/- standard error of the mean]) and in 11 with all grafts open but all parent arteries occluded left ventricular ejection fraction was unchanged (0.51 +/- 0.02 to 0.54 +/- 0.03). Left ventricular ejection fraction was decreased in eight men with occlusion of all vein grafts whether or not occlusion of the parent coronary arteries had occurred. The results suggest that occlusion of the parent coronary arteries in the presence of a patent vein graft does not unfavorably alter left ventricular ejection fraction or segmental wall motion, whereas graft occlusion is associated with deterioration of left ventricular ejection fraction and segmental motion whether or not the parent artery is also occluded.

Adult↗
PubMed1976

Candida precipitins as a diagnostic aid in Candida endocarditis.

We report a case of aortic valve homograft endocarditis secondary to preoperative contamination of the homograft. Candida precipitins, determined by double immunodiffusion, were an invaluable aid in diagnosis in the presence of negative venous blood cultures.

Adult↗
PubMed1976

Correlation of platelet survival time with occlusion of saphenous vein aorto-coronary bypass grafts.

Platelet survival time is frequently shortened in patients with coronary artery disease, and it is one of several factors that might contribute to graft occlusion after saphenous vein coronary artery bypass (CAB). In 35 patients with CAB, average platelet survival (autologous labeling with 51Chromium) was shortened in 20 with one or more saphenous vein grafts occluded and normal in 15 with all grafts open. Of 15 with all grafts open, individual levels of platelet survival were normal in 10 while in 20 with one or more grafts occluded platelet survival was normal in only one. Platelet survival was not altered by coronary surgery and nine of ten with shortened platelet survival pre-operatively had graft occlusion. Platelet survival did not correlate with either parent artery occlusion or serum lipoproteins. These findings suggest a relationship between shortened platelet survival and saphenous vein graft occlusion and suggest that platelet suppressant therapy might be useful in preventing graft occlusion.

Adult↗
PubMed1976

Isosorbide dinitrate and intra-aortic balloon pumping in preinfarctional angina. Effects on central circulatory dynamics.

The dynamics of the central circulation were measured by a radionuclidic technique in 18 men with high-risk preinfarctional angina who received therapy with isosorbide dinitrate (n equals 18), intra-aortic balloon pumping (n equals 8), or both (n equals 8). Administration of 5 mg of isosorbide dinitrate sublinqually was associated with a reduction in stroke volume index (SVI), cardiac index (CI), systemic arterial blood pressure, and left ventricular end-diastolic volume (LVEDV) and with increased left ventricular ejection fraction (LVEF). Intra-aortic balloon pumping did not alter SVI or CI, but decreased systolic blood pressure and LVEDV and increased LVEF and diastolic blood pressure. The combination of therapy with isosorbide dinitrate and intraaortic balloon pumping resulted in decreased SVI, systolic blood pressure, and LVEDV and increased LVEF. Thus, therapy with isosorbide dinitrate reduced left ventricular preload, and intra-aortic balloon pumping reduced blood pressure, which resulted in a decreased LVEDV and an increase in LVEF. Therapy with isosorbide dinitrate and intra-aortic balloon pumping act to alter central circulatory dynamics in favor of reducing myocardial oxygen demand.

Adult↗
PubMed1976

Homograft and prosthetic aortic valve replacement: a comparative study.

Homograft aortic valve replacement was done in 103 patients and prosthetic aortic valve replacement in 106 between January 1962 and December 1973. Patients who received homograft and prosthetic valves were compared with respect to age, sex, preoperative functional impairment, infection, dyspnea, angina, hemodynamics, chest X-ray, electrocardiogram, associated operations, early and late mortality, and valve failure. Combined total mortality was 28% (12% operative, 8% first postoperative year, 8% late). Ten percent of valve required replacement. One year after operation, 70% of survivors were asymptomatic, 27% were improved, and 3% were unchanged or between homograft and prosthetic valve replacement. Valve-related failure and infections were more common after homograft aortic valve replacement. Emboli, hemorrhage, and hemolysis were commoner after prosthetic valve replacement. Fungal infections occurred in five homograft patients but in no patient with a prosthetic aortic valve. Severe properative symptoms or recent endocarditis was associated with greater mortality and valve failure in both the homograft and the prosthetic series. Increased mortality and failure was also seen in patients with either preoperative aortic regurgitation with high left ventricular end-diastolic pressure and low cardiac index, or aortic stenosis with cardiomegaly or roentgenographic evidence of congestive heart failure. Therefore, in two series of patients at equal risk, mortality and valve failure were similar for homograft and prosthetic aortic valve replacement.

Adolescent↗
PubMed1975

Bacterial endocarditis caused by Oerskovia turbata.

Oerskovia turbata is a yellow, motile actinomycete, which before now has only been found in soil and has not been known to cause disease in man or animals. It was isolated from 29 cultures of blood taken during 6 months from an urban pensioner after homograft replacement of his aortic valve. The combination of ampicillin, sulfamethoxazole, and trimethoprim was lethal for O. turbata in vitro; however, antimicrobial therapy alone failed to eradicate the patient's infection. Cure was achieved after the infected homograft was replaced with a prosthetic aortic valve. Although the source of O. turbata in this patient is unknown, sterilization of homograft valves with antimicrobial solutions is difficult. Moreover, environmental contamination during cardiopulmonary bypass is common. Oerskovia turbata is another opportunistic pathogen of man.

Aged↗
PubMed1975

Improvement of myocardial and other vital organ functions and metabolism with a simple method of pulsatile flow (IABP) during clinical cardiopulmonary bypass.

A simple, safe, and effective method of producing pulsatile flow during cardiopulmonary bypass (CPB) with intra-aortic balloon pumping (IABP) was used in 56 patients. No complications were associated with IABP. Myocardial metabolic studies, including coronary sinus lactates, mycoardial venous-arterial lactate differences, myocardial lactate extraction, and "excess lactate" were determined serially during the first hour of CPB. Changes in myocardial metabolism were statistically less abnormal in pulsatile flow (PF) patients when contrasted with a comparable group of nonpulsatile flow (NPF) patients. The changes were probably myocardial in origin since alterations in arterial lactates and lactate/pyruvate ratios were similar in both groups. In a comparable group of coronary bypass NPF patients, the percentage of left ventricular ejection fractions fell during the immediate postoperative period, whereas it rose in the PF group. Over-all body tissue injury (lactic dehydrogenase) and probably hepatocellular injury (serum glutamic oxalacetic transaminase) were less apparent in the PF patients. Postoperative low-cardiac-output syndrome did not occur in the PF patients and supportive drugs and diuretics were not needed. PF does not produce excessive hemolysis. This procedure may improve mortality rates by improving myocardial and other vital organ perfusion and by sustaining their function during weaning from CPB. This technique may prove superior to other forms of PF and is indicated in patients with severe left ventricular or other vital organ dysfunction and/or prolonged CPB.

Aspartate Aminotransferases↗