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Biomedical subjects

W E Walker

Publications and source records attributed to W E Walker.

At least 55 records · Page 3Linked to original sources
PubMed1984

Early elective senning repair: optimal operative strategy for simple transposition of the great arteries.

After the inception of a new pediatric cardiovascular service, we reviewed the management of the first eight consecutive neonatal patients with simple transposition of the great arteries who underwent successful balloon atrial septostomy. Immediate cardiac catheterization and septostomy were performed, and all were discharged in good condition. Each returned at about 6 months of age for elective Senning repair in which the hypothermic arrest technique was used. All survived and are doing well at follow-up that now averages 20 months, and is over 1 year in every instance. While late follow-up is not yet available, it appears that this approach of early, elective repair of simple transposition can give optimal results, even within the context of a new clinical program.

Journal Article↗
PubMed1984

Perforation of the innominate vein: complication of a Swan-Ganz catheter.

A 71-year-old woman underwent placement of a Swan-Ganz pulmonary artery catheter after induction of general anesthesia for a triple-vessel coronary bypass procedure. The surgery was uneventful; however, the patient was in profound shock upon arrival in the cardiac intensive care unit. After a short delay, caused in part by the measurement of high "wedge" pressures, she was returned to the operating room where a laceration of the right innominate vein was repaired. Resuscitation was unsuccessful and death ensued in the operating room. Percutaneous pulmonary artery catheterization is very worthwhile in the management of patients with complicated problems; however, we should be more cautious in considering the risks involved when selecting patients for this procedure.

Journal Article↗
PubMed1984

Coronary artery revascularization without cardiopulmonary bypass.

At the Texas Heart Institute between October 1969 and August 1983, there were 191 single bypass procedures performed without pump oxygenator support. These cases have been divided into two groups: Group I (160 patients) represents the time period from October 1969 through December 1981 and includes our experience with single vessel left anterior descending (LAD) coronary artery bypass without pump oxygenator support; Group II (31 patients) represents the period between January 1982 and August 1983 and includes our initial operative experience in patients with failed percutaneous transluminal coronary angioplasty (PTCA). Of 145 primary operations in Group I patients, 113 were single bypasses to the right coronary artery with a postoperative infarction rate of 3.5% (4/113). Single bypass to the left anterior descending (LAD) coronary artery in 32 patients who underwent operation early in the series was associated with a postoperative infarction rate of 18.7% (6/32) and is no longer performed without pump oxygenator support. Fifteen patients had previous coronary bypass operations and underwent single bypass without pump as a second procedure. Postoperative infarction rate in this redo group was 6.6% (1/15). Long-term follow-up data was obtained on all patients from 1 to 11 years after surgery (mean follow-up, 4 years). Four late cardiac deaths occurred at 2,3,4 and 7 years in the primary operation group (3.5%) 4/113. One late death occurred at 7 years in the redo group (6.6%) 1/15. In Group II, failed PTCA accounted for 39% of the 31 patients who underwent single right bypass without pump support; there were no perioperative infarctions and one death. Coronary bypass can be safely and effectively employed without pump oxygenator support if performed expeditiously and limited to right coronary lesions which have an adequate distal vessel. This technique has become more useful with the advent of attempted PTCA for single coronary lesions.

Journal Article↗
PubMed1984

Early bypass grafting following intracoronary thrombolysis with streptokinase.

Early bypass grafting following intracoronary thrombolysis with streptokinase may be indicated in patients with acute coronary artery thrombosis and severe coronary disease. To evaluate this approach, we prospectively studied 41 patients (32 men and nine women, mean age 53 years) with acute infarction. Emergency cardiac catheterization was performed within 18 hours after onset of chest pain and intracoronary streptokinase was given. All patients underwent bypass 3 to 10 days later (mean 7 days). Serial gated radionuclide left ventricular angiograms to determine ejection fraction were obtained on hospital admission, preoperatively, and 3 to 6 months later. Thirty-four patients had complete occlusion of the artery supplying the infarcted segment. In 30 patients (88%) reperfusion was not successful. In seven patients the artery was not totally thrombosed. Thirty-two patients (78%) had multivessel disease. An average of 2.8 grafts per patient were placed with an operative mortality of 2% (one patient). Serial measurements of ejection fraction were obtained in 23 patients in whom the admission ejection fraction was less than 50%. There was a significant increase in ejection fraction from admission (33% +/- 11%) to the preoperative measurement (41% +/- 9%, p less than 0.001), and this improvement persisted at follow-up (40% +/- 14%). Intracoronary streptokinase has been shown to restore blood flow to infarcting myocardium and to improve left ventricular performance. In patients with significant organic stenosis, the risk of bypass grafting 3 to 10 days after intracoronary streptokinase infusion appears to be no different from the risk of elective operation performed at a time remote from an acute infarction.

Adult↗
PubMed1984

Esophageal obstruction caused by mediastinal histoplasmosis: beneficial results of operation.

A patient presented with progressive dysphagia and chest pain. Radiologic investigation showed extrinsic compression of the esophagus by enlarged, calcified, mediastinal lymph nodes. Immunologic studies suggested that this was due to previous histoplasmosis, currently inactive. The nodes were excised at thoracotomy, with complete relief of symptoms. Operative management was most appropriate because of the apparent inactivity of the infection, the severity and progressive nature of the symptoms, and the possible prophylaxis of mediastinal fibrosis, a well-documented complication of histoplasmosis.

Adult↗
PubMed1983

Resection of aortic arch aneurysms: a comparison of hypothermic techniques in 60 patients.

Hypothermic circulatory arrest has been used to facilitate resection of aneurysms of the aortic arch. During a five-year period, two methods of hypothermic arrest were compared in 60 patients. In Group 1, 20 patients underwent deep hypothermia (14 degrees to 18 degrees C) and circulatory arrest to allow repair of the transverse arch under optimal conditions. A hospital mortality of 50% occurred and was attributed to uncontrolled hemorrhage and cerebral or cardiac complications. In Group 2, modified techniques were employed in 40 patients and included moderate levels of hypothermia (22 degrees to 26 degrees C) and simplified operative methods, which reduced the duration of circulatory arrest and shortened the length of perfusion. Pretreatment of plasma-soaked Dacron grafts by autoclaving eliminated serious bleeding problems. A marked improvement in patient survival (90%) and reduction in postoperative complications were observed after adoption of these modifications. The improved results in the present series have reconfirmed our belief that this type of intervention is the preferred approach to aneurysms of the aortic arch.

Adolescent↗
PubMed1983

Sustained improvement in left ventricular function and mortality by intracoronary streptokinase administration during evolving myocardial infarction.

One hundred eighty-eight patients with acute myocardial infarction were studied prospectively from August 1980 to September 1982. One hundred thirty-six of these patients were entered into a intracoronary streptokinase study after informed consent was obtained. The remaining 52 patients, who either met exclusion criteria for the study or refused to participate, served as a control group and were treated as those in the study group except that they did not undergo emergency cardiac catheterization. Left ventricular function was determined in both groups by gated radionuclide ejection fraction (EF) on admission to the hospital, at discharge, and 6 months after discharge. With successful reperfusion up to 18 hr after onset of chest pain, mean left ventricular function in the study group improved (EF 39 +/- 13% on admission and 46 +/- 12% at discharge; p less than .001). Mean EF in control patients and those not achieving reperfusion did not change from admission to discharge. Mean EF at 6 month follow-up was not significantly different than at discharge in the study group or the control group. Total cardiac mortality in the control group was 19% compared with 10% in the study group (p = .06, NS). When patients admitted in pulmonary edema or shock (Killip class III or IV) were excluded from both groups, total cardiac mortality in the study group was significantly lower (4%) compared with in the control group (12.5%, p less than .05. The administration of intracoronary streptokinase during evolving myocardial infarction up to 18 hr after onset of chest pain may result in decreased mortality and sustained improvement in left ventricular function.

Aged↗
PubMed1983

Gunshot wound of the aortic arch and esophagus: unusual indication for ascending-to-abdominal aortic bypass graft.

Repair of a gunshot wound of the aortic arch produced severe "coarctation" of the aorta at the origin of the left subclavian artery, requiring the placement of an ascending-to-abdominal aortic bypass graft. This produced an acceptable hemodynamic result, although 10 days later the patient died of infection caused by a concomitant injury of the esophagus. The operative approach for repair of complex injuries of the intrathoracic great vessels can be improved by experience with multiple approaches to elective repair of thoracic vessels.

Journal Article↗
PubMed1983

The St. Jude medical valve: early clinical results in 253 patients.

The St. Jude Medical cardiac valve is a low-profile, bileaflet, central-flow prosthesis made entirely of pyrolytic carbon. A total of 261 St. Jude valves were implanted in 253 patients during a 25-month period. Perioperative mortality for the entire series was 9.1%, including patients undergoing reoperation for valve disease and those having associated cardiac procedures. There were four nonfatal thromboembolic episodes during the follow-up period, resulting in a risk of thromboembolism for aortic and mitral valves of 2.1% and 2.1% per patient year, respectively. There were no instances of structural failure of the valve, and no valve-related hemolysis occurred. Two-year actuarial survival was 95%. Hemodynamic studies indicate that the valve has the lowest transvalvular pressure gradient of any prosthetic mechanical valve available, and we believe it is the valve of choice for patients in whom a prosthetic mechanical valve is indicated.

Journal Article↗
PubMed1983

Early experience with the ionescu-shiley pericardial xenograft valve. Accelerated calcification in children.

Recognizing the problems of thromboembolism and anticoagulation in children and the high incidence of calcification in porcine valves in children, we hoped that the Ionescu-Shiley valve might be a good choice in the younger age group. We implanted 2,372 Ionescu-Shiley valves in 2,167 patients between 1978 and 1982, of which 30 were in children 16 years of age and younger. Although there have been no known instances of thromboembolism, valve infection, or valve disruption in this group of children, seven (23%) have already required reoperation for calcific stenosis. Although calcification appears maximal in postpubertal children less than 17 years of age, we consider it unwise currently to place these valves in any child and have returned to mechanical valves for this purpose.

Adolescent↗
PubMed1982

Streptokinase reperfusion and early surgical revascularization in patients with acute myocardial infarction.

During a 21-month period, 150 patients with acute myocardial infarction were offered entry into a study comprising emergency cardiac catheterization, streptokinase infusion for thrombus if present, and coronary artery bypass surgery where appropriate. Forty refused or were excluded, and served as a control group. Approximately 80% of the remainder had coronary thrombosis and obtained benefit as a group from streptokinase reperfusion. Among the 44 who had coronary artery bypass mortality was low except in those having cardiogenic shock at the time of operation. Those without coronary thrombosis appeared to have a better result from early than from delayed operative revascularization. It appears that both streptokinase reperfusion and early coronary artery bypass have a beneficial role in the management of patients with acute myocardial infarction.

Cardiac Catheterization↗
PubMed1982

Open aortic anastomosis: improved results in the treatment of aneurysms of the aortic arch.

Over a 7-month period, 15 consecutive patients underwent resection and reconstruction of the transverse aortic arch for a variety of pathologic lesions using moderate systemic hypothermia (24 degrees C) and brief circulatory arrest. Simplified surgical techniques were developed to allow rapid repair. The "open" aortic technique facilitated repair of arch aneurysms, aortic dissections and obstructive lesions of the arch tributaries. The mean cerebral ischemic time was 11.2 +/- 1.5 minutes (mean +/- SEM). Moderate hypothermia afforded adequate cerebral and myocardial protection during circulatory arrest and shortened the duration of extracorporeal bypass necessary for the cooling and rewarming phases (87 +/- 8 minutes). Dacron grafts preclotted by a new method greatly reduced postoperative blood loss. Since these simplified techniques were adopted, 14 patients (93%) have survived aortic arch replacement, with minimal postoperative morbidity. One patients with severe preoperative left ventricular dysfunction died of cardiac failure after operation. These results suggest that aortic arch replacement can be performed safely and with low operative risk.

Aorta, Thoracic↗
PubMed1981

Surgical treatment of aneurysms of the transverse aortic arch: experience with 25 patients using hypothermic techniques.

Surgical treatment of aneurysms of the transverse aortic arch has been a challenge to cardiovascular surgeons. The problems include protection of the brain and spinal cord from ischemic or embolic injury, prevention of hemorrhage and coagulopathy, and prevention of myocardial damage during prolonged extracorporeal circulation. Two methods are described. Group 1 included 20 patients in whom deep hypothermic conditions were induced (12 degree to 16 degree C) followed by circulatory arrest and partial exsanguination. In this group a 50% hospital mortality occurred. Patients in Group 2 underwent moderate induced hypothermia (24 degree to 26 degree C) with continuous cerebral perfusion during the period of peripheral circulatory arrest. Four of 5 patients survived this technique, leading us to believe this method is preferred over the deeper levels of hypothermia. A method of preclotting the Dacron graft with platelet-rich plasma and autoclaving is described. It has eliminated interstitial bleeding through fabric grafts.

Adolescent↗
PubMed1981

Blind nasotracheal intubation.

Nasotracheal intubation is a useful technique for intubating the conscious, active patient. This can be accomplished blindly without sedation or muscle relaxation and without the trauma of laryngoscopy. The method is not new but is not well known in proportion to its usefulness. Attention to detail renders the procedure safe, certain and atraumatic for patient and physician alike.

Humans↗
PubMed1980

Contribution of an educational phase to stress inoculation of speech anxiety.

A study is described in which students anxious about speeches were treated by variations of stress inoculation training. The purpose of the experiemnt was to evaluate the contribution of an educational phase to the training. Three treatment groups received either the educational phase only, the skills phase only, or both. These were compared with a no-treatment control group. The education-only group was the only group to improve significantly on self-reported anxiety measured before giving a public speech. The education-only and combination group imporved on self-reported self-efficacy as a speaker. All groups improved on behavioral rating of anxiety. Discussion focuses on the apparent potency of using an educational model in the treatment of anxiety. Future research is suggested for delineating the conditions under which education is a powerful ingredient.

Anxiety↗