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Biomedical subjects

W G Wolfe

Publications and source records attributed to W G Wolfe.

At least 55 records · Page 3Linked to original sources
PubMed1990

The utility of transesophageal echocardiography and Doppler color flow imaging in patients undergoing cardiac valve surgery.

To assess the value of intraoperative transesophageal echocardiography during cardiac valve surgery, 154 consecutive patients who had a valve operation in conjunction with pre- and postcardiopulmonary bypass transesophageal imaging were studied. Prebypass imaging yielded unsuspected findings that either assisted or changed the planned operation in 29 (19%) of the 154 patients. Imaging immediately after bypass revealed unsatisfactory operative results that necessitated immediate further surgery in 10 (6%) of the 154 patients. Postbypass left ventricular dysfunction, prompting administration of inotropic agents, was identified in 13 patients (8%). Transesophageal echocardiography proved most useful when both two-dimensional and Doppler color flow imaging were employed in patients undergoing a mitral valve operation, where surgical decisions based on echocardiographic results were made in 26 (41%) of 64 cases. Postbypass echocardiographic findings identified patients at risk for an adverse postoperative outcome. Of 123 patients whose postbypass valve function was judged to be satisfactory, 18 (15%) had a major postoperative complication and 6 (5%) died, whereas of 7 patients with moderate residual valve dysfunction, 6 (86%) had a postoperative complication and 3 (43%) died (p less than 0.05 for both). Likewise, of 131 patients with preserved postbypass left ventricular function, 12 (9%) had a major complication and 7 (5%) died, whereas of 23 patients with reduced ventricular function, 17 (73%) had a postoperative complication and 6 (26%) died (p less than 0.05 for both). These data indicate that intraoperative transesophageal echocardiography is useful in formulating the surgical plan, assessing immediate operative results and identifying patients with unsatisfactory results who are at increased risk for postoperative complications.

Cardiopulmonary Bypass↗
PubMed1990

Comparison of medical and surgical therapy for uncomplicated descending aortic dissection.

To guide the choice of medical versus surgical therapy for patients with descending (type B) aortic dissection (tear in the descending aorta without involvement of the ascending aorta), multivariate survival analysis was applied to 136 patients admitted to two medical centers between 1975 and 1988 with acute (n = 89) or chronic (n = 47) descending dissection: group 1, all 136 patients; group 2, 106 patients without rupture, pulse loss, or visceral organ compromise; and group 3, 56 patients from group 2 without major cardiac or renal disease (23 surgical and 33 medical). Group 3 medical and surgical subgroups were well matched for baseline characteristics and were potential candidates for either mode of therapy. By Cox model analysis, significant predictors of mortality were pleural rupture, other dissection complications, increasing age, and cardiac disease (all p less than 0.01). Surgical versus medical therapy was not an independent determinant of survival in any of the three groups for acute or chronic dissection. Survival probabilities for all group 3 patients at 1, 5, and 10 years were 0.94, 0.87, and 0.32 (medical) and 0.90, 0.80, and 0.50 (surgical). Despite the limitations of this retrospective study (including the possibility of undefined treatment selection biases), these data suggest that medical or early surgical therapy is associated with equivalent outcome in selected patients with uncomplicated acute or chronic descending aortic dissection.

Adrenergic beta-Antagonists↗
PubMed1989

Right and left ventricular performance during and after abdominal aortic aneurysm repair.

To evaluate the effect of aortic occlusion and limb reperfusion on global and regional function of the right and left ventricle during infrarenal abdominal aortic aneurysm repair, 23 patients underwent five intraoperative first-pass radionuclide angiocardiograms: 1) before the skin incision, 2) at aortic cross-clamp, 3) 20 minutes after aortic occlusion, 4) at unclamping, and 5) after skin closure. A subset of twelve patients had simultaneous transesophageal echocardiography to evaluate left ventricular wall stress. Parameters measured included the electrocardiogram (ECG), heart rate, blood pressure, pulmonary artery pressure, the cardiac output, the left and right ventricular ejection fractions, left ventricular volumes, and left ventricular wall stress. Significant changes (p less than 0.01) were observed at aortic clamping in the left ventricular ejection fraction (from 0.56 to 0.48), end-diastolic volume (from 171 to 225 ml), end-systolic volume (from 85 to 127 ml), mean blood pressure (from 82 to 91 mmHg), and meridional end-systolic wall stress (from 53 to 67 10(3) dyne/cm2). Once the clamp was removed, significant variations were seen in the left ventricular ejection fraction (from 0.51 to 0.58), end-diastolic volume (from 205 to 187 ml), end-systolic volume (from 105 to 94 ml), mean blood pressure (from 84 to 69 mmHg), and meridional end-systolic wall stress (from 67 to 46 10(3) dyne/cm2). No differences were observed between the two aortic occlusion studies, and the baseline level of function was recovered in all parameters during the last study. These data quantify the changes in heart function that occur during abdominal aortic aneurysm operation and demonstrate that the majority of the adaptations that occurred were due to a variation in afterload.

Aged↗
PubMed1989

Blood conservation in cardiac surgery. Preliminary results with an institutional commitment.

To evaluate the effect of blood conservation in cardiac surgery, use of blood products was analyzed in patients undergoing CABG before and after implementation of blood conservation techniques. Age, sex, coronary anatomy, ejection fraction, cardiopulmonary bypass time, and the preoperative hematocrit, platelet count, and clotting studies were similar in both groups. Methods of blood conservation included autologous transfusion of blood withdrawn before bypass, autotransfusion of shed mediastinal blood, strict protocols for transfusion, and acceptance of normovolemic anemia. With blood conservation, 25.5% of patients received no transfusions and 54.9% received blood only. Significant reductions (p less than 0.001) were achieved in the transfusion of blood from 6.8 +/- 2.4 to 2.3 +/- 2.6 units per patient and of plasma from 2.5 +/- 2.2 to 0.6 +/- 2.0 units per patient. Reductions in the use of platelets and cryoprecipitate were substantial, although not significant. Total donor exposure was reduced significantly from 13.1 +/- 7.3 to 4.3 +/- 6.7 donors per patient. The postoperative hematocrit was significantly lower and remained so at discharge. However, 30 days later there was no difference. This reduction in transfusion requirements decreased costs and donor exposure.

Aged↗
PubMed1989

Resection of abdominal aortic aneurysm in patients with low ejection fractions.

The perioperative and long-term survival of patients who undergo resection of abdominal aortic aneurysm is often determined by coexisting cardiac disease. This study evaluates the influence of left ventricular ejection fraction on both perioperative and long-term morbidity and mortality. Preoperative ejection fraction was measured in 104 of 208 patients undergoing elective abdominal aortic aneurysm resection. Nineteen patients were found to have ejection fractions less than 0.35, and this group was compared to 85 patients with ejection fractions greater than 0.35. The two groups did not differ significantly in terms of age, sex, preoperative renal function, or smoking status. The groups were significantly different with respect to the prevalence of prior myocardial infarction (79% of the low ejection fraction group vs 31% of the high ejection fraction group) and symptoms equivalent to New York Heart Association class II or greater (47% of the low ejection fraction group vs 24% of the high ejection fraction group) but not prior myocardial revascularization procedure (42% of the low ejection fraction group vs 31% of the high ejection fraction group). Surgical factors including aneurysm size, duration of aortic cross-clamping, and extent of arterial replacement did not differ significantly between the two groups. The perioperative mortality was not significantly different (low ejection fraction, 5%; high ejection fraction, 2%). The cumulative life-table survival of the two groups was not statistically different. Two patients in the low ejection fraction group died in the follow-up period, yielding a 4-year actuarial survival of 0.74. This is compared to 10 deaths and actuarial survival of 0.63 (p = NS) in the high ejection fraction group. We conclude that patients should not be denied aneurysm resection solely on the basis of left ventricular ejection fraction.

Aged↗
PubMed1989

Assessment of left ventricular functional preservation during isolated cardiac valve operations.

To evaluate intraoperative changes in myocardial performance during valvular operations, ventricular functional measurements were obtained in 16 patients before and after elective cardiac valvular replacement. Six patients had mitral regurgitation, four had mitral stenosis, and six had calcific aortic stenosis; all patients underwent isolated mitral or aortic valve replacement. Cold potassium crystalloid cardioplegia, topical hypothermia, and low-flow systemic hypothermia were employed uniformly. Just before and 10 minutes after cardiopulmonary bypass was discontinued, left ventricular pressure and volume data were recorded at four to five different steady-state levels of filling produced by blood infusion or withdrawal from the aortic cannula (mean end-diastolic pressure range, 10-22 mm Hg; mean end-diastolic volume range, 120-168 ml). Portable first-pass radionuclide ventriculography and simultaneous micromanometry were used for construction of left ventricular pressure-volume loops from which stroke work and end-diastolic volume were calculated. Two-dimensional transesophageal echocardiograms also were recorded, and epicardial pacing maintained heart rate as constant as possible. As compared with prebypass measurements, echocardiographic left ventricular wall volume changed insignificantly after the valvular procedures (178-181 ml/m2, p greater than 0.5). The stroke work-end-diastolic volume relationship before and after operation was highly linear in all studies (mean = 0.97). The slope and x intercept of this relationship did not change significantly after operation, indicating a stable level of left ventricular function (from 12.7 x 10(4) to 10.0 x 10(4) ergs/ml and from 67 to 57 ml, respectively; p greater than 0.3).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiopulmonary Bypass↗
PubMed1988

Management of an unusual case of congenital lobar emphysema.

A 10-week-old infant, who presented with respiratory embarrassment, was found to have an azygos lobe complicated by congenital lobar emphysema. The pediatric work-up, operative management, and postoperative course are described. The cases presenting at Duke University Medical Center are reviewed.

Acute Disease↗
PubMed1988

Alveolar cell carcinoma of the lung: a retrospective analysis of 205 patients.

From 1970 to 1986, survival of 205 patients with alveolar cell carcinoma was retrospectively studied. Analysis examined the predictive value of presenting symptoms and diagnostic screening results for pathological Stage III or IV disease (advanced) and survival. The lesion presented as a peripheral mass in 121 patients (59%) and as an infiltrate in 84 (41%). Follow-up data were available on 199 patients (97%). Variables analyzed included indices of background or risk factors, presenting symptoms, diagnostic test results, and clinical management. Seventy-nine patients (39%) had a histological diagnosis of advanced disease by TMN staging criteria. Of the 152 deaths (74%), 117 (77%) were related to the pulmonary carcinoma. Univariate analysis associated short-term and long-term anorexia, weight loss, generalized weakness, and profound dyspnea with advanced disease and ultimately with death due to cancer. Multivariate logistic regression analyses suggested that weight loss and dyspnea disclosed independent information about the likelihood of advanced disease for this population (p less than 0.0003). Cox proportional hazard regression analyses of survival revealed a significant association between weight loss and death due to alveolar cell carcinoma after pathological stage was taken into account (p = 0.001). In this series, the 80 patients with Stage I disease had the best prognosis (5-year survival of 55%). There was no significant difference in disease-free survival between patients having wedge resection (N = 17) and those having lobectomy (N = 63) for Stage I disease.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1987

Mechanisms of healing in the injured lung treated with the Nd-YAG laser.

An experimental study was done to evaluate the pattern of healing after sealing an incision in the pulmonary parenchyma with the Nd-YAG laser. Gross and histologic examinations of healing were compared with those of lung cauterized or sutured with chronic catgut. The results indicate that the use of the Nd-YAG laser to seal small vessels and air leaks has distinct advantages over cautery or suture closure of incisions in pulmonary tissue.

Animals↗
PubMed1987

Early results with combined modality therapy for carcinoma of the esophagus.

Since January 1984, 74 patients (61 men, 13 women; age range: 43-76 years) with carcinoma of the esophagus were evaluated. Fifty-two patients had squamous cell carcinoma and 22 patients had adenocarcinoma. Sixty-three patients had preoperative chemotherapy and radiation that consisted of cis-platinum and VP-16 for squamous cell carcinoma and cis-platinum 5-FU for adenocarcinoma combined with 4500-6000 rads. Thirty-four patients were staged inoperable at the completion of the 4-month treatment regimen. Eleven patients had surgery alone because they refused or were not candidates for the preoperative regimen. Twenty-nine patients completed the combined modality regimen and have had esophagogastrostomy. All patients receiving chemotherapy and radiation demonstrated improved swallowing and a dramatic reduction of tumor mass early in the course of therapy and have been able to maintain oral nutrition without other support in the posttreatment period. Of the 34 patients who had chemotherapy and radiation therapy as palliation, 18 are currently living. One patient died secondary to complications of chemotherapy, another patient died at 9 months of myocardial infarction. The remaining patients died secondary to their disease. Of the 29 patients who had radiation therapy and chemotherapy plus esophagogastrostomy, 25 are alive. There were no operative deaths. One patient died at 9 months of stroke. Three other patients had recurrence and died 1 year after surgery. Of the 11 patients who had surgery alone, two have died of the disease. Of the 29 patients who completed the integrated therapy, 10 had no evidence of residual tumor in the specimen, and in an additional five patients only microscopic foci were evident. These early results are an encouragement to continue the multidiscipline approach to carcinoma of the esophagus in the hope that the quality of life and disease-free interval, as well as ultimate survival, will be enhanced.

Adenocarcinoma↗
PubMed1987

Hypoxia enhances unilateral lung injury by increasing blood flow to the injured lung.

We hypothesized that in unilateral lung injury, bilateral hypoxic ventilation would induce vasoconstriction in the normal lung, redirect blood flow to the injured lung, and cause enhanced edema formation. Unilateral left lung injury was induced by intrabronchial instillation of 1.5 ml/kg of 0.1 N HCl. After HCl injury, blood flow to the injured left lung decreased progressively from 0.70 +/- 0.04 to 0.37 +/- 0.05 l/min and percent of flow to the injured left lung (QL/QT) decreased from 37.7 +/- 2.2 to 23.6 +/- 2.2% at 240 min. Exposure to hypoxia (12% O2) for three 10-min episodes did not affect QL/QT in normal animals, but after unilateral HCl injury, it caused blood flow to the injured left lung to increase significantly. A concomitant decrease in blood flow occurred to the noninjured right lung, resulting in a significant increase in QL/QT. The enhanced blood flow to the injured lung was associated with a significant increase in the wet-to-dry lung weight ratio in the dependent regions of the injured lung. These findings demonstrate that in unilateral HCl-induced lung injury, transient hypoxia can enhance blood flow to the areas of injury and increase lung edema formation.

Animals↗
PubMed1986

Management of benign and malignant lesions of the trachea and bronchi with the neodymium-yttrium-aluminum-garnet laser.

Fifty patients with lesions of the trachea or bronchi have been treated with the neodymium-yttrium-aluminum-garnet laser. Forty-three patients had advanced carcinoma of the lung with pulmonary infection or abscess distal to an obstructing bronchial lesion or else had hemoptysis. Benign lesions were seen in seven patients. A total of 72 laser treatments were administered for obstruction and/or hemoptysis. There was no significant morbidity and only one hospital death occurred, which was unrelated to the laser therapy. Among the 43 patients with malignant disease, obstructive complications and hemoptysis were controlled in 39. All those with benign lesions have been significantly improved. Presently 22 patients with malignant disease remain alive and are symptomatically improved. The longest survival after successful laser treatment has been 73 weeks, and 34 survived longer than eight weeks. This laser is a very effective means of managing patients with benign lesions and offers significant palliation for patients with hemoptysis and advanced obstructing carcinoma of the trachea or main-stem bronchus.

Adult↗
PubMed1985

Subvalvular left ventricular pseudoaneurysm after mitral valve replacement: two-dimensional echocardiographic findings.

Disruption of the posterior mitral anulus is a rare complication of mitral valve replacement that may result in subvalvular left ventricular pseudoaneurysm formation. Such pseudoaneurysm formation was easily recognized by two-dimensional echocardiography in a 54 year old man 3 years after his second mitral valve replacement. The finding was confirmed by cineangiography and direct surgical inspection. Recognition of this rare complication of mitral valve replacement has therapeutic importance because surgical correction is necessary.

Cineangiography↗
PubMed1985

Aneurysm of aberrant subclavian artery with a review of the literature.

Aneurysms arising in an aberrant subclavian artery are rare but constitute a potentially lethal condition that can be treated successfully when appropriately identified. Virtually all patients have a superior mediastinal mass that may be asymptomatic, but usually patients have symptoms of dysphagia, chest pain, or shortness of breath. An accurate diagnosis can now be made noninvasively with computerized tomography. The presence of an aneurysm of an anomalous subclavian artery is an indication for surgical resection. Resection of the aneurysm may be approached through either a right or left thoracotomy. Reestablishment of continuity of flow to the right subclavian artery decreases the risk of ischemia of the extremities and prevents development of the subclavian steal syndrome. Reestablishment of flow to the right subclavian artery is more easily performed through a right thoracotomy incision but this approach limits control of the aorta at a possibly treacherous connection between aorta and aneurysm. In such circumstances a preliminary extra-anatomic reconstitution of flow to the right subclavian artery followed by a left thoracotomy may be preferable. A 67-year-old woman is described who had resection and grafting of an aneurysm in an aberrant right subclavian artery together with a review of the literature and a discussion of problems in the management of patients with this condition.

Adult↗