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Biomedical subjects

A C Galloway

Publications and source records attributed to A C Galloway.

At least 91 records · Page 5Linked to original sources
PubMed1991

Sternal wound infections and use of internal mammary artery grafts.

Previous studies have provided conflicting evidence as to whether an increased risk of mediastinitis is associated with use of the internal mammary artery as a coronary bypass graft. In this study the effects of internal mammary artery grafts on wound complications were analyzed in a prospective, nonrandomized fashion. At New York University Medical Center from January 1985 through May 1988, 2356 patients underwent isolated coronary revascularization. Among these patients 1394 received one or more internal mammary artery grafts (group I) and 962 had vein grafts only (group II). Group I had a mean age of 59.5 years versus 67.7 years in group II; diabetes was equally present in both groups (22.7% versus 24.7%). Operative mortality rate was 1.3% in group I and 5.6% in group II. Sternal infection was significantly more prevalent in group I (2.2%, 31/1394) than in group II (0.8%, 8/962). Multivariate analysis revealed that aortic crossclamp time, use of a single internal mammary artery graft, use of a double mammary graft, and diabetes were associated with increased risk of sternal infection. The use of bilateral internal mammary artery grafting doubled the odds ratio of the risk compared with use of a single mammary graft, and the combination of diabetes and double internal mammary artery grafts increased the odds ratio 13.9-fold. Patients with an internal mammary artery graft who had sternal infection had a longer period of hospitalization than patients without a mammary artery graft who had sternal infection. We conclude that the risk of sternal infection is increased by the use of an internal mammary artery graft, especially use of double mammary grafts in the presence of diabetes.

Aged↗
PubMed1991

Biventricular distribution of cold blood cardioplegic solution administered by different retrograde techniques.

Although retrograde cardioplegia has been shown to provide adequate overall protection to the myocardium, delivery of cardioplegic solution to the right ventricle and septum is poor. We used an animal model of occlusion of the left anterior descending coronary artery to study the effects of modifying the conditions of retrograde cardioplegia administration on delivery to the right and left ventricles. Adult mongrel dogs (n = 12) were each given five retrograde injections of microsphere-labeled cardioplegic solution at 10-minute intervals. Four injections were made directly into the coronary sinus with ostial balloon occlusion at the following dosages and pressures: (1) 10 ml/kg at 30 mm Hg, (2) 20 ml/kg at 30 mm Hg, (3) 10 ml/kg at 50 mmHg, and (4) 20 ml/kg at 50 mm Hg. A fifth dose (20 ml/kg) was given directly into the right atrium at 50 mm Hg. Delivery of cardioplegic solution to the left and right ventricles was significantly reduced when the right atrial route was compared with the coronary sinus route at the same dosage and pressure (for left ventricle, 6.0% +/- 1.4% versus 22.7% +/- 11.4%/100 gm, p less than 0.001; for right ventricle, 0.7% +/- 0.2% versus 4.1% +/- 0.4%/100 gm, p less than 0.001). Septal delivery was less than that to the anterior and posterior left ventricle (10.4% +/- 1.3% versus 30.3% +/- 3.9% and 27.9% +/- 3.1%/100 gm, p less than 0.0001) for all injections. Delivery to the body of the right ventricle was less than that to the inflow and outflow tracts (1.8% +/- 0.2% versus 4.5% +/- 0.7% and 8.4% +/- 1.5%/100 gm, p less than 0.0001). These results indicate that, in this model, (1) the right atrial route provides less overall cardioplegic solution to both ventricles than direct retrograde coronary sinus cardioplegia and (2) regional abnormalities in distribution with direct retrograde coronary sinus cardioplegia are not affected by changes in the dosage or pressure of injection.

Animals↗
PubMed1990

Ten-year experience with aortic valve replacement in 482 patients 70 years of age or older: operative risk and long-term results.

A retrospective analysis of an institutional experience with aortic valve replacement (AVR) in patients 70 years of age or older during 1976 to 1987 was performed. The study was prompted in part by the current interest in palliative aortic valvoplasty, an interest based to a certain extent on the impression that AVR in the elderly has a high mortality. The mean age of the patients was 75.0 +/- 4.0 years (+/- the standard deviation) (range, 70 to 89 years). Eighty-three percent of patients received porcine valves and 17%, mechanical valves. Preoperatively 32% were in New York Heart Association class III, and 59% were in class IV. Operative mortality was 5.6% for elective isolated AVR for aortic stenosis (19% of all patients), 8.2% for all isolated AVR (38%), and 12.4% overall. Concomitant operative procedures were done in 62.0%; AVR with coronary artery bypass grafting (42%) had an operative mortality of 14.3%. Multivariate analysis showed significant predictors of operative mortality to be emergency operation (p less than 0.01), isolated aortic regurgitation (p = 0.01), and previous cardiac operation (p = 0.02). Follow-up (34 +/- 27 months) was 94% complete. Five-year survival from late cardiac-related death was 81.0%. The constant yearly hazard rate for late death for patients 70 years of age or older who underwent AVR was 5.42% per year, which is similar to the 5.77% per year rate calculated for age-matched and sex-matched controls. Five-year freedom from reoperation was 99%; from late thromboembolic complications, 91%; and from late anticoagulant-related complications, 94%. Freedom from all valve-related morbidity and mortality was 61% at 5 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1989

A comparison of mitral valve reconstruction with mitral valve replacement: intermediate-term results.

The continued good results after mitral valve reconstruction prompted this retrospective study to compare operative and late results from our institutional experience since 1976 with 975 porcine mitral valve replacements (MVRs) (1976 to December 1987), 169 mechanical MVRs (1976 to December 1987), and 280 Carpentier-type mitral valve reconstructions (CVRs) (1980 to mid-1988). The operative mortality was 2.0% for isolated CVR, 6.6% for isolated mechanical MVR, and 8.5% for isolated porcine MVR. The overall operative mortality was 5.0% for CVR, 16.6% for mechanical MVR, and 10.6% for porcine MVR. The overall 5-year survival including hospital deaths was 76% for CVR, 72% for mechanical MVR, and 69% for porcine MVR. By multivariate analysis, the predictors of increased operative risk and of decreased survival were age, New York Heart Association functional class IV status, previous cardiac operation, and performance of concomitant cardiac surgical procedures. The type of valvular procedure was not predictive of operative risk or overall survival. The 5-year freedom from reoperation was 94.4% for nonrheumatic patients having CVR, 77.4% for rheumatic patients having CVR, 96.4% for mechanical MVR, and 96.6% for porcine MVR (p less than 0.05, rheumatic patients with CVR versus both MVR groups). The 5-year freedom from all valve-related morbidity and mortality was significantly better for valve reconstruction compared with both types of valve replacement. Thus, the operative risk and late survival obtained after mitral valve reconstruction were at least equivalent to those obtained after MVR. In addition, patients receiving mitral valve reconstruction had less valve-related combined morbidity than patients receiving valve replacement, thus making mitral valve reconstruction preferable in some patients with mitral insufficiency.

Adolescent↗
PubMed1989

Ten-year operative experience with 165 aneurysms of the ascending aorta and aortic arch.

Results of surgery in 165 patients with aneurysms of the ascending aorta and aortic arch during 1978-1988 were analyzed retrospectively. Etiology included 29% dissection, 22% atherosclerosis, 22% cystic-medial necrosis, and 27% other causes. Concomitant procedures on the aortic valve were performed in 65% of patients (valvular replacement in 37%, valve-conduit in 23%, and valvular resuspension in 5%), and 13% underwent concomitant coronary artery bypass surgery. Major changes in our operative technique for such aneurysms have been introduced during the last 5 years, especially use of a continuous suture-graft-inclusion technique in 99% of patients, use of circulatory arrest in 59%, and use of an open hemiarch repair in 32%. Hospital mortality dropped from 17.9% during the first 5 years of the study period to 12.3% in the last 5 years despite increasing complexity of the cases encountered. Operative mortality was 7.6% for ascending aortic aneurysmal repair; 5.3% for valve-conduit procedure; 8.8% for open hemiarch repair; and 30.8% for repair of extensive aneurysms involving the aortic arch and significant portions of the descending aorta. Multivariate analysis showed that, of the variables examined, significant predictors of increased operative risk were age (p less than 0.05) and extension of an ascending aortic aneurysm to the descending aorta or involvement of the aortic arch (p less than 0.001). The incidence of stroke was 2.4%, with only one stroke since 1983 despite more extensive use of circulatory arrest since that time. Follow-up was 94% complete, with a mean (+/- SD) follow-up interval of 28 +/- 24 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Current concepts of mitral valve reconstruction for mitral insufficiency.

In recent years, there has been a renewed interest in surgical reconstruction of the insufficient mitral valve because of reconfirmation of the limitations of existing prosthetic and bioprosthetic valves. A follow-up study, including late functional data, of 148 patients who underwent mitral valve reconstruction at our institution was combined with a review of the literature to assess the current status of mitral reconstruction. The results indicate that mitral reconstruction by Carpentier techniques is widely applicable, durable, and relatively free of complication. Freedom from late thromboembolic and anticoagulant complications is particularly notable. These factors could prove to justify earlier operative intervention in patients with mitral insufficiency before permanent myocardial damage evolves. As mitral valve reconstruction techniques become more familiar and widely used, mitral reconstruction may become the operative procedure of choice for mitral insufficiency, especially insufficiency due to degenerative disease.

Actuarial Analysis↗
PubMed1988

Percutaneous cardiopulmonary bypass limits myocardial injury from ischemic fibrillation and reperfusion.

Percutaneous implementation of cardiopulmonary bypass (PCPB) with a synchronous pulsatile pump has been shown to be an efficient means of unloading the heart. Therefore, this technique may provide a practical and effective method for treating patients undergoing a major cardiac catastrophe who are unresponsive to the usual resuscitative efforts. We tested whether PCPB could effectively unload the heart and provide myocardial salvage during left anterior descending (LAD) coronary artery occlusion complicated by ventricular fibrillation in the canine model (n = 13). All 13 dogs fibrillated within 20 minutes of LAD occlusion, and none could be successfully resuscitated by manual cardiac compression, sodium bicarbonate administration, antiarrhythmic agent administration, and electrical defibrillation. All 13 dogs were then placed on PCPB by way of the right jugular vein and right femoral artery; in seven, we used a synchronous pulsatile pump and in six a standard roller pump. No vent was placed in the left ventricle. All animals returned to normal sinus rhythm within 20 minutes of institution of PCPB. The LAD snare was released after 2 hours, and all animals were maintained on PCPB during 3 hours of reperfusion. At sacrifice, the area of infarction was determined by staining with triphenyltetrazolium chloride and was expressed as a percentage of the left ventricular area-at-risk for infarction. The tension time index was also measured and expressed as percent change from baseline. The left ventricular area-at-risk for infarction was similar in both groups (31.5% for roller pump vs. 29.2% for pulsatile pump; p greater than 0.05), but the area of infarction as a percentage of the area at risk was significantly smaller in the pulsatile-pump group (22.0%) than in the roller-pump group (35.4%; p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Surgical treatment for aneurysm of aberrant subclavian artery based on a case report and a review of the literature.

Experiences with the recent successful treatment of a patient with an aneurysm arising from an aberrant subclavian artery are described. The reported experiences with surgical treatment by others were reviewed in detail: Only 16 such patients were found, with a surprising frequency of serious complications. These data led to the conclusion that a two-stage approach, through right cervical and left thoracotomy incisions, seems to offer the ideal method of treatment for this unusual problem.

Aneurysm↗
PubMed1988

Long-term results of mitral valve reconstruction with Carpentier techniques in 148 patients with mitral insufficiency.

There have been few relatively complete follow-up studies of long-term mitral valve function after Carpentier-type surgical reconstruction. Between January 1980 and May 1986, 148 patients underwent Carpentier reconstruction for mitral valve disease (43% degenerative and 30% rheumatic). Operative mortality was 5.4% overall (1.2% for isolated mitral reconstruction), and follow-up (mean, 26 months) was completed for all survivors. Five-year survival from late cardiac death was 90.0%, as was 5-year freedom from postreconstruction mitral valve replacement. Postreconstruction mitral replacement was needed in eight patients, in only five for failure of repair. Follow-up echocardiographic studies on 83.2% (104 of 125) of eligible patients showed 92.3% were free of significant (3+ or 4+) mitral regurgitation. Freedom from mitral valve replacement or recurrent severe (4+) insufficiency was 84.4% at 5 years overall, but was lower for the rheumatic type of mitral disease than for the degenerative type (71.6% vs. 88.3%). At 5 years, 95.2% of patients were free from thromboembolism without the necessity for long-term warfarin (Coumadin) therapy. At follow-up, 95.3% of survivors had improved to New York Heart Association Class I or II. The functional durability of mitral reconstruction and consistently high level of freedom from late endocarditis and thromboembolic and anticoagulant complications support the value of the Carpentier method of mitral reconstruction for mitral insufficiency, especially insufficiency due to degenerative disease.

Adolescent↗
PubMed1987

A comparison of methods for limiting myocardial infarct expansion during acute reperfusion--primary role of unloading.

Current use of angioplasty, thrombolysis, and surgical techniques for prompt reperfusion of an acute myocardial infarction raises questions concerning the optimum reperfusion technique for maximum myocardial salvage. Alterations in the conditions of reperfusion and/or the composition of the initial reperfusate can exert a significant effect on the extent of myocardial salvage. In an effort to define an optimum reperfusion technique, we used 40 dogs in a series of experiments in which the left anterior descending coronary artery (LAD) was snared for 2 hr followed by reperfusion by one of five methods for 4 hr. In addition, in a control group(group I, n = 6) the LAD was occluded for 6 hr without any reperfusion. In group 2 (n = 12), simulating medical reperfusion, reperfusion was achieved by simply releasing the snare for 4 hr. Group 3 dogs (n = 6) were placed on pulsatile left atrial-femoral bypass throughout 4 hr of reperfusion. Group 4 dogs (n = 9) were placed on percutaneous, synchronized pulsatile cardiopulmonary bypass during reperfusion. The procedure in group 5 (n = 7) dogs simulated coronary artery bypass grafting with cardiopulmonary bypass and cold blood, low-Ca++ cardioplegia during reperfusion. Group 6 (n = 6) was treated similarly except that during reperfusion amino acid-enriched cardioplegia was administered by warm induction techniques. At the end of 4 hr of reperfusion, the left ventricular area of infarction was determined by triphenyltetrazolium chloride staining and expressed as a percentage of the left ventricular area at risk for infarction (area of infarction [AI]/area at risk [AR]).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Percutaneous cardiopulmonary bypass with a synchronous pulsatile pump combines effective unloading with ease of application.

Percutaneous total cardiopulmonary bypass offers the advantage of rapid, simple implementation without the need for thoracic incision and provides the ability to support both left and right ventricular failure as well as pulmonary insufficiency. Previous studies using roller pump percutaneous bypass were only partially successful because of the inability to effectively unload the left ventricle. In the present experiment we attempted to determine in a normal canine model whether use of synchronous pulsatile pumping for percutaneous bypass could overcome this problem. Fourteen dogs were placed on percutaneous bypass for 1 hour. A roller pump was used in seven and a synchronous pulsatile pump with an electrocardiogram triggering mechanism in the other seven. All animals were maintained on percutaneous bypass for 1 hour. In the pulsatile pump group there was a significantly greater percent decrease from baseline in tension-time index (-56.3% versus -19.1%, p less than 0.01) and in myocardial oxygen consumption (-45.8% versus +2.1%, p less than 0.05) and a significantly greater percent increase in the endocardial/epicardial blood flow ratio (27.6% versus -6.5%, p less than 0.01) than in the roller pump group. These results show that superior unloading can be achieved by percutaneous pulsatile bypass compared with percutaneous roller pump bypass. The findings suggest that percutaneous total cardiopulmonary bypass with a synchronous pulsatile pump offers a relatively simple but effective method for providing appropriate patients with temporary hemodynamic stability before cardiac catheterization or medical or surgical revascularization.

Animals↗
PubMed1986

Experiences with 1643 porcine prosthetic valves in 1492 patients.

Sixteen hundred and forty-three porcine prosthetic values (1102 Carpentier-Edwards, 541 Hancock) were implanted in 1492 patients at New York University Medical Center between January 1976 and June 1983. The aortic valve alone was replaced in 786 patients (53%), mitral valve alone in 556 (37%), and multiple valves in 143 patients (9.6%). Concomitant coronary artery bypass was performed in 326 patients (22%). There were 116 deaths within 30 days of operation (7.8%). Follow-up (mean: 42 months) was completed in 94% of survivors and revealed that late survival from cardiac-related death was 87% at 5 years and 81% at 7 years, with no significant difference between the Carpentier-Edwards and Hancock patients. Late thromboembolic complications, however, were significantly more frequent in Hancock patients at all intervals from 1-7 years (p less than 0.05), whether in the aortic or mitral position. Patients with coronary artery disease who had concomitant coronary bypass showed a survival from late cardiac death that did not differ significantly from that of patients undergoing valve replacement alone. Before operation, 87% of patients were in New York Heart Association Class III or IV, but after operation 80% were in Class I or II. Late anticoagulant complications, endocarditis, and valve dysfunction were relatively rare. These results from a series of such size, duration, and representative numbers of two types of porcine bioprosthesis confirm excellent results with porcine prostheses in the first 4-5 years following operation.

Animals↗
PubMed1985

The value of early repair for total anomalous pulmonary venous drainage.

A total of 20 children with total anomalous pulmonary venous drainage (TAPVD) underwent complete repair within the past six years. The drainage was supracardiac in 11, infracardiac in seven, and into the coronary sinus in two. At repair mean age was nine weeks, and weight was 3.7 km. Operative technique in extracardiac types included complete mobilization of the common vein with division of anomalous channel when possible. The incision in the confluent vein was extended into the lobar veins when necessary to permit extensive incorporation of this structure into the posterior wall of the left atrium and resulted in a nonobstructing stellate-type anastomosis. Operative mortality was 10% (2 of 20). Deaths occurred only in the group of infants in whom severe obstruction to pulmonary venous return required emergency operation, and one of these patients has persistent neurologic deficit. Late cardiac catheterization has been performed in 11 of 18 survivors. Nine had no or only minor abnormalities and two required reoperation. There have been no late deaths with follow-up of 2-8 years (mean = 4 years). Currently, all of the survivors are without cardiac symptoms and only one requires cardiac medication. Our experience identifies pulmonary venous obstruction with critical symptoms as the major operative risk factor in patients with TAPVD. With early operation prior to onset of critical symptoms, mortality is low and functional results are excellent.

Cardiac Catheterization↗
PubMed1985

A clinical evaluation of the hypothesis that rupture of the left ventricle following mitral valve replacement can be prevented by preservation of the chordae of the mural leaflet.

Experiences with 14 patients undergoing rupture of the left ventricle following mitral valve replacement over a period of 9 years have been described. Three different types have been recognized. Before 1978, most injuries occurred in the atrioventricular groove, apparently resulting from traction that insidiously avulsed the mitral annulus from the underlying left ventricular muscle. Several changes in operative technique, described in the text, were made to prevent this traction avulsion. Following the adoption of these principles, rupture in the atrioventricular groove virtually disappeared. A second type of injury, strut perforation, has been recognized in only one patient, a small 81-year-old female in whom the prosthesis inserted was too large for the ventricular cavity. Translucent obturators were subsequently developed not only to size the left ventricle but also to note the location of the post of the porcine prosthesis before insertion. Further problems of this type have not been seen. The most puzzling, and currently the most significant, problem is a third type of rupture, the mid-ventricular rupture, suggested as Type III by Miller in 1978 and described in detail by Cobbs in 1977 and 1980. The phenomenon seems to be a true spontaneous rupture of a thin left ventricle, usually occurring in small elderly women with mitral valve disease. If the friability of the left ventricle is transiently increased with potassium cardioplegia, such ventricles may spontaneously rupture following division of the chordae to the annulus of the mural leaflet. If this concept is correct, a rupture in some patients can best be prevented by preserving these chordae. It is well realized, of course, that a fortunate narrative experience of 3 1/2 years does not have any statistical value concerning a complication that occurs in 1 to 2% of operations. The experiences are reported, however, because to our knowledge, the untethered loop hypothesis has not been previously evaluated in a large number of consecutive patients operated on. Future comparison of experiences reported by others should make it possible to determine whether or not this concept is correct.

Aged↗
PubMed1984

Do ischemic hearts stimulate endothelial cell growth?

The development of myocardial ischemia is known to elicit the formation and enlargement of collateral vessels. The stimulus for these events is unknown. We have investigated the possibility that cardiac tissue releases a factor that can stimulate endothelial cell proliferation. Hearts from New Zealand rabbits were made progressively ischemic by differential hypothermia. Extracts from these hearts were tested for their growth-stimulating ability and were found to increase the proliferation of fetal bovine aortic endothelial cells as well as DNA synthesis by 3T3 cells. The level of activity in the extracts appears to be related to the degree of ischemia as measured by creatine phosphokinase levels. The liberation of an endothelial cell growth factor by ischemic cardiac tissue may function in the initiation and/or potentiation of coronary collateral formation.

Animals↗