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Biomedical subjects

C Mavroudis

Publications and source records attributed to C Mavroudis.

At least 145 records · Page 8Linked to original sources
PubMed1983

Reconstruction of complex thoracic defects with myocutaneous and muscle flaps. Applications of new flap refinements.

This report describes reconstructions of complex thoracic defects with myocutaneous and muscle flaps that were modified by several recent refinements of flap design. These refinements comprise a second generation of myocutaneous and muscle flaps, which have substantially increased versatility and extended applications, as compared with the originally described flaps. These refinements include the following: (1) segmentally split latissimus dorsi and pectoralis major flaps, which transfer only one muscle segment as the flap and leave other segments of the same muscle in situ to preserve motor function; (2) pectoralis major fasciocutaneous flaps, which are extended by abdominal skin and fascia to provide longer, larger flaps; (3) reversed pectoralis major and latissimus dorsi flaps, which are supplied by secondary, distal vascular pedicles that permit flap use when the primary vascular supply is interrupted; and (4) island vascular pedicle muscle flaps, which allow intercostal passage for reconstruction of intrathoracic defects and cavities. The anatomic bases for these flap refinements are described, and the advantages provided are discussed.

Adult↗
PubMed1982

Preliminary experience with aspirin for anticoagulation in children with prosthetic cardiac valves.

Twenty-four children (ages 1 to 18 years, mean 12.2 years) underwent 27 operations for aortic, mitral, or combined aortic and mitral valve replacement. There was 1 operative death. Of the 23 operative survivors (12 aortic, 8 mitral, 3 combined valve replacement), only 5 were given warfarin for long-term anticoagulation. The remaining 18 (10 aortic, 8 mitral valve replacement) were given aspirin (plus dipyridamole in 5). Twelve of the 18 had at least one mechanical valve (11 Björk-Shiley and Beall valves; 1 Björk-Shiley valve was replaced with a Beall disc valve as the child grew). These 18 patients were followed for 1 to 59 months (mean, 20.4 months). There was no thrombotic, embolic, or bleeding complications. There were 2 late deaths (one cardiac). Review of the available literature indicates that in children with prosthetic cardiac valves, aspirin (with or without dipyridamole) provides adequate protection against thromboemboli and avoids the hemorrhagic complications associated with warfarin.

Adolescent↗
PubMed1982

Surgical management of complete atrioventricular canal.

Successful correction of complete atrioventricular (AV) canal depends on accurate assessment of surgical anatomy and preservation of valve tissue to avoid postoperative valvular insufficiency. From 1975 to 1980 there were 68 patients aged 2 months to 17 years (median age 12 months) who underwent correction for the complete form of AV canal. Forty-six percent had associated anomalies which included patent ductus arteriosus, right aortic arch, pulmonic stenosis, and ostium secundum defect. Two types of repairs were employed: group I-Teflon patch closure of the ventricular septal defect (VSD) by division of the common leaflets into mitral and tricuspid components: Group II-Teflon patch closure of the VSD without division of common leaflets by fashioning the patch between the chordae tendineae and under the common leaflets. The atrial septal defect component was closed separately with pericardium or Teflon. Overall mortality is related to presence of (1) elevated pulmonary vascular resistance (Wood units greater than 4), (2) prior palliative operations, or (3) associated cardiovascular anomalies. Repair of complete AV canal without splitting the common leaflets preserves valve tissue. The act of splitting the common leaflets and reattaching the mitral and tricuspid components to the VSD patch by necessity sacrifices valve tissue. Although this may not be significant in older children, it becomes important in infants, for the sacrificed valve tissue comprises a greater proportion of the whole. Moreover, patch disruption of the reattached mitral and tricuspid components can be avoided if the common leaflets are not split.

Adolescent↗
PubMed1982

Repair of congenital cardiac lesions during the first week of life.

Repair of congenital cardiac defects in the neonatal period has been associated with a high operative mortality thought to be due to the adverse effects of cardiopulmonary bypass. This has prompted the use of closed palliation in such patients. Between 1957 and 1981, 195 of 988 patients (20%) operated in the first year of life were critically ill neonates ages 1-7 days. Fifty-six underwent repair using cardiopulmonary bypass. These included l29 operations at the arterial level, five for aortic stenosis, 19 for pulmonary stenosis and five for transposition of the great arteries using the switch procedure; 25 at the atrial level, eight for transposition of the great arteries, 16 for total anomalous pulmonary venous connection, and one for combined total anomalous pulmonary venous connection and anomalous systemic venous connection; and two at the ventricular level, one for tetralogy of Fallot and one for double-outlet right ventricle. The hospital survival rate in this group was 91%. Palliations using cardiopulmonary bypass were performed in an additional 27 patients, including right ventricular outflow tract patches in 20. The survival rate in this group was 73%. The survival rate was 100% for closed repairs and 76% for palliations. These results demonstrate that cardiopulmonary bypass per se is not a determinant of survival in the neonate; an effective repair combined with proper diagnostic techniques and postoperative management are probably the critical factors.

Cardiopulmonary Bypass↗
PubMed1981

Improved survival in management of empyema thoracis.

Empyema thoracis following pneumonia, trauma, and surgical procedures continues to be a source of major morbidity and mortality. We retrospectively reviewed the hospital records of 100 patients treated for empyema thoracis at San Francisco General Hospital during the past 10 years. The causes of empyema in these patients were as follows: pneumonia 44%, trauma 24%, surgical and invasive procedures 15%, lung abscess 11%, and hematogenous spread 6%. Ten patients in this series died of sepsis from necrotizing pneumonia or overwhelming injuries caused by trauma. Streptococcus (31%), Staphylococcus (21%), and Bacteroides (15%) were the organisms most commonly isolated. Bacterial isolates were single in 55%, multiple 42%, and absent in 3%. The type of organism did not correlate with severity of disease or eventual requirement for thoracotomy, pleural débridement, or Eloesser procedure. Successful methods of treatment included aspiration in 9%, tube thoracostomy in 63%, pleural débridement and drainage in 7%, and an Eloesser procedure in 11%. Because our patients were often debilitated from chronic alcoholism, drug addiction, and major trauma, conservative management was initially tried. In most patients empyema resolved with tube thoracostomy. Pleural débridement should be reserved for patients with special problems such as multiple loculation or purulence inaccessible to percutaneous tube placement. the Eloesser procedure is indicated in patients who have an infected residual pleural space that persists despite adequate tube drainage.

Adolescent↗
PubMed1980

Management of acute cervicothoracic vascular injuries.

One hundred eighty-one patients with 218 acute cervicothoracic vascular injuries underwent operations for diagnosis, resuscitation, and control of hemorrhage. The patients were divided into three clinical groups depending on their clinical status. Group I consisted of 105 patients who were hemodynamically stable and able to undergo diagnostic measures: Group II consisted of 41 patients who remained unstable and required immediate operation; Group III consisted of 35 patients who were moribund and underwent emergency room thoracotomy. The mortality rates were 4% for Group I, 15% for Group II, and 80% for Group III with an overall mortality rate of 21%. Angiography was performed in 53% of the stable Group I patients. This allowed specific identification of lesions such as arteriovenous fistula in eight patients and aortic disruption in 12 patients. Thirty-five Group III patients had thoracotomy performed in the emergency room and seven survived (20%). A vigorous clinical approach is recommended to minimize morbidity. A different approach is described for each of the three clinical groups of patients.

Adolescent↗
PubMed1979

Extracellular space, water, and ion concentration in the hypertrophied rat myocardium.

Extracellular space (ECS), water, and intracellular ion concentration were determined in the normal and hypertrophied rat myocardium. Theoretical measurements of myocardial ECS based on a mathematical model (9.31%) closely approximated the observed results in the normal myocardium (12.8%) and hypertrophied myocardium (11.7%). Observed results confirmed theoretical considerations of no change in ECS with hypertrophy. ECS and water content were higher in the right ventricle than the left ventricle, but intracellular electrolytes remained unchanged. Myocardial hypertrophy did not alter these relationships.

Animals↗
PubMed1978

To pulse or not to pulse.

Pulsatile and nonpulsatile blood flow have been intensely studied for cardiopulmonary bypass (CPB), isolated organ perfusion, and myocardial preservation. Although early studies differed, later ones have shown the benefits of pulsatile flow. Kidney function, lymph flow, and oxygen consumption are increased during pulsatile perfusion. Also, nonpulsatile CPB increases total peripheral resistance and mean arterial pressure, which are related to time of perfusion. Theories to account for the superiority of pulsatile flow include: (1) "vascular shocks" causing physical displacement of tissues, which changes the boundary layer of interstitial fluid around cell membranes and enhances diffusion ;(2) increased lymph movement during pulsatile flow; and (3) pulsatile energy ensuring the patency of the vascular beds and preventing shunting. New methods to create pulsatile flow and their adaptation to the standard roller pump are discussed.

Animals↗
PubMed1978

Hemodilution causes decreased compliance in puppies.

Cardiopulmonary bypass and hemodilution in the newborn have been associated with increased myocardial edema, which may be due to immature connective tissue formation. Five adult and four puppy dogs were placed on bypass while compliance and ventricular function (intraventricular balloon) were measured during normohemoconcentration (NH) (hematocrit 45.1, osmolality 307) and hemodilution with normal saline (hematocrit 24.7, osmolality 307). Compared with NH, the adult group showed no change in compliance or function after 90 min of hemodilution. The puppy group showed a marked decrease in compliance with hemodilution compared to NH (P < 0.001) without change in ventricular function when peak systolic pressure was plotted against end-diastolic volume. Electron micrographs confirmed greater edema formation in the puppy group than the adult group with hemodilution. These changes demonstrate that the newborn heart is more sensitive to edema formation than the adult during hemodilution and that filling pressures do not necessarily reflect ventricular performance during the early post-perfusion period when compliance is decreased.

Animals↗