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Dive into the research topics where James R. Stewart is active.

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Featured researches published by James R. Stewart.


The Annals of Thoracic Surgery | 1991

Cavoatrial tumor thrombectomy using cardipulmonary bypass without circulatory arrest

James R. Stewart; John A. Carey; W. Scott McDougal; Walter H. Merrill; Michael O. Koch; Harvey W. Bender

Of 29 patients with inferior vena caval tumor thrombus, 14 with supradiaphragmatic extension were deemed suitable for operation. Patients (age, 7.5 to 70 years) had renal cell carcinoma (n = 8), Wilms tumor (n = 2), transitional cell carcinoma (n = 1), and adrenal carcinoma (n = 3). Seven patients had stage III disease, and 7 patients had stage IV disease. Two patients (group A) had unresectable disease at exploratory celiotomy, 4 patients (group B) underwent tumor thrombectomy without cardiopulmonary bypass, and cardiopulmonary bypass was employed in 8 patients (group C). Three of 8 group C patients had Budd-Chiari syndrome at diagnosis. Cardiopulmonary bypass with moderate hypothermia, and inferior vena caval interruption (clip or filter), was employed in all patients. There were no perioperative deaths. Transient neurological impairment was observed postoperatively in 2 patients. Coagulopathy developed in 1 patient who had hepatic encephalopathy and Budd-Chiari syndrome preoperatively and in another patient in whom protamine could not be administered. No patient had acute renal failure requiring hemodialysis. Median survival is 41 and 17 months in groups B and C, respectively. Some authors have advocated profound hypothermia and circulatory arrest in these patients. We find that satisfactory visualization and excision can be performed with cardiopulmonary bypass and moderate hypothermia, avoiding potential renal, hepatic, neurological, and septic complications associated with circulatory arrest.


The Annals of Thoracic Surgery | 1994

Thymectomy for the myasthenia gravis patient : factors influencing outcome

William H. Frist; Shanti Thirumalai; Christopher B. Doehring; Walter H. Merrill; James R. Stewart; Gerald M. Fenichel; Harvey W. Bender

Thymectomy is a therapeutic option for patients with myasthenia gravis with moderate to severe disability. To document the efficacy of thymectomy coupled with medical therapy to treat this disease and to identify clinical factors that influence outcome, the clinical courses of all 46 patients (12 male and 34 female; mean age, 30 +/- 16 years) with myasthenia gravis who underwent thymectomy through a median sternotomy at a single institution over a 21-year period were reviewed. Clinical staging was determined preoperatively, at 1 month, 6 months, and 12 months postoperatively, and at last follow-up (mean time, 75 months postoperatively) using the Oosterhuis classification. Changes in severity of illness were graded as deteriorated, unchanged, improved, or much improved. Preoperative Oosterhuis classification was 3.3 +/- 1.1 and at last follow-up, 1.4 +/- 1.2 (p = 0.022). At last follow-up, 40 patients (87%) were in the improved or much improved category, and 6 patients were in the deteriorated or unchanged category. Status at 1 month, 6 months, and 12 months after operation predicted outcome at last follow-up visit (p = 0.007, p = 0.005, and p = 0.001, respectively). Clinical factors that positively influenced outcome were age less than 45 years (p = 0.004), female sex (p = 0.0309), and preoperative stage (p = 0.021).


The Annals of Thoracic Surgery | 1989

Ten years' experience with the senning operation for transposition of the great arteries: Physiological results and late follow-up

Harvey W. Bender; James R. Stewart; Walter H. Merrill; John W. Hammon; Thomas P. Graham

We report our results in 93 consecutive infants and children who underwent atrial repair of simple transposition of the great arteries using the Senning operation between February 1978 and February 1988. Mean age at operation was 5.6 +/- 6.3 months (range, 1 week to 4 years); 60 were less than 6 months old. There were 65 boys and 28 girls. Operative mortality was 5.4%, and there has been 1 late death. Average follow-up is 45.1 months with 39 followed more than 3 years and 25 followed more than 5 years. Postoperative cardiac catheterization was performed in 43 patients. Right ventricular ejection fraction at rest averaged 0.50 +/- 0.09 and was normal in 26 patients. Response of right ventricular ejection fraction to afterload stress was abnormal in 12 of 14 patients tested. Right ventricular ejection fraction increased normally during exercise in 6 patients, but was abnormal in 15. Mild tricuspid regurgitation was noted in 10 patients. Mild obstruction of the superior vena cava was noted in 4 patients. Baffle leak requiring reoperation occurred in 1 patient. Seventy-two of 80 patients are in sinus rhythm by latest electrocardiogram. Postoperative electrophysiological studies were performed in 34 patients and Holter monitoring was performed in 22. A major arrhythmia occurred in 8 patients: 3 required a pacemaker for junctional rhythm or sinus node dysfunction, 2 have symptomatic or inducible supraventricular tachycardia, 2 have junctional rhythm, and 1 has sick sinus syndrome. Eight additional patients have delayed sinus node recovery time. At last follow-up, 78 children (97.5%) are in New York Heart Association functional class I, and 2 (2.5%) are in class II.(ABSTRACT TRUNCATED AT 250 WORDS)


The Annals of Thoracic Surgery | 1993

Preliminary results with neoadjuvant therapy and resection for esophageal carcinoma

Steven J. Hoff; James R. Stewart; John L. Sawyers; Michael J. Murray; Walter H. Merrill; R. Benton Adkins; David H. Johnson

Between December 1988 and August 1992, 68 patients with adenocarcinoma (n = 39) and squamous carcinoma (n = 29) of the esophagus were entered prospectively in a treatment protocol to receive two cycles of cisplatin, 5-fluorouracil, etoposide, leucovorin, and 3,000 cGy of radiation to the involved esophagus and adjacent mediastinum, followed by resection. There were four deaths during chemotherapy, and 7 patients had a decline in condition or were denied operation. Fifty-six patients have come to operation, and 1 awaits resection. Twenty-two patients had transhiatal esophagectomy and 29 patients had esophagogastrostomy with a combined abdominal and right thoracic approach. Five patients did not undergo resection at operation. There was one hospital death (2%). A complete response to preoperative therapy was seen in 12 patients (21%): 5 of 20 with squamous cancer (25%) and 7 of 36 with adenocarcinoma (19%). Average follow-up is 19 months. Median survival in these patients after entrance in the protocol is 24 months. Actuarial survival at 12, 18, and 24 months is 72% (confidence limits, 66% and 78%), 53% (confidence limits, 46% and 60%), and 51% (confidence limits, 44% and 58%). Significantly better survival was associated with adenocarcinoma (p = 0.041). There is no survival advantage based on complete response to preoperative therapy. This neoadjuvant regimen is effective in patients with squamous carcinoma and adenocarcinoma. These preliminary results demonstrate an improved median and actuarial survival compared with historical controls in 137 patients operated on between 1966 and 1985 at our institution.


The Annals of Thoracic Surgery | 1996

Safety of remote aortic valve replacement after prior coronary artery bypass grafting.

Steven J. Hoff; Walter H. Merrill; James R. Stewart; Harvey W. Bender

BACKGROUNDnA previous coronary artery bypass grafting (CABG) procedure may complicate subsequent aortic valve replacement (AVR). However, the operative risks and long-term outcome of patients who undergo these two procedures remain poorly defined.nnnMETHODSnThe medical records of all patients undergoing AVR between February 1986 and September 1995 were reviewed retrospectively. The patients selected for analysis had previously undergone CABG.nnnRESULTSnWe performed AVR in 23 consecutive patients who had previously undergone CABG (mean number of grafts, 2.8). The AVR was performed an average of 7.6 years after CABG (range, 2 to 17 years). There were 20 men and 3 women, with a mean age of 69 years (range, 56 to 85 years). Twenty patients were operated upon for aortic stenosis (mean gradient 54 mm Hg, mean valve area 0.7 cm2), and 3 patients underwent operation for aortic regurgitation. The average aortic valve gradient at the initial revascularization operation was 8 mm Hg (range, 0 to 29 mm Hg). There was no correlation between the aortic valve gradient at the initial revascularization and the interval between CABG and AVR. At the second operation, AVR was performed alone in 11 patients, combined with repeat CABG in 11 patients (mean number of grafts, 1.4), and with mitral valve replacement in 1 patient. A mechanical prosthesis was selected in 14 patients, and a bioprosthesis was used in 9 patients. There were no perioperative deaths. There were five late deaths at an average follow-up of 44 months. The 5-year actuarial survival was 71%.nnnCONCLUSIONSnPrevious CABG poses added technical challenges at the time of reoperation for AVR. The operation can be performed safely, with the expectation of satisfactory long-term survival.


Journal of Cardiovascular Electrophysiology | 1994

Effects of Procainamide and Lidocaine on Defibrillation Energy Requirements in Patients Receiving Implantable Cardioverter Defibrillator Devices

Debra S. Echt; Steven T. Gremillion; John T. Lee; Dan M. Roden; Katherine T. Murray; Mark Borganelli; Diane M. Crawford; James R. Stewart; John W. Hammon

Effects of Procainamide and Lidocaine on Defibrillation. intntduction: In acute canine studies, lidocaine. but not prucainamidc, increases defibrillation energy requirements. We evaluated the effects of lidocaine or procainamide on defihrillation energy requirements in 27 patients undergoing intraoperative testing fur implantable cardioverter dcfibrillator device placement.


The Annals of Thoracic Surgery | 1990

Reappraisal of localized resection for subvalvar aortic stenosis.

James R. Stewart; Walter H. Merrill; John W. Hammon; Thomas P. Graham; Harvey W. Bender

Between June 1972 and August 1989, we operated on 45 patients with fixed subaortic stenosis. Discrete membranous stenosis was present in 28 patients and tunnel stenosis, in 13. Four patients had subvalvar stenosis complicating double-outlet right ventricle. There were 33 male and 12 female patients. Mean age at operation was 7.1 +/- 4.3 years (range, 6 months to 21 years). Local resection of the fibrous membrane was performed in 26 patients. Local resection was combined with myectomy in 18 patients. Aortoventriculoplasty (modified Konno procedure) was required at operation in 3 patients. There were three perioperative deaths at initial operation and two deaths at the time of reoperation. Follow-up ranges from 1 month to 17 years (average follow-up, 47.0 months). Reoperation for recurrent obstruction has been required in 12 patients (27%), and 3 patients have required a second reoperation. Mild to moderate aortic regurgitation was present in 17 patients. Subaortic stenosis is a spectrum of anatomical derangements ranging from a discrete fibrous membrane to a long, tortuous fibrous tunnel with aortic annulus hypoplasia. Successful removal of a discrete fibrous membrane can be followed later by recurrent stenosis necessitating myectomy or aortoventriculoplasty. Correction of subvalvar aortic stenosis can be followed by recurrent stenosis necessitating reoperation as long as 17 years after the initial procedure.


The Annals of Thoracic Surgery | 1986

Free radical scavengers and myocardial preservation during transplantation.

James R. Stewart; Edward B. Gerhardt; Chris J. Wehr; Todd Shuman; Walter H. Merrill; John W. Hammon; Harvey W. Bender

The efficacy of oxygen radical scavengers in preservation of left ventricular (LV) function after prolonged hypothermic global ischemia was investigated in a model of orthotopic cardiac transplantation in sheep. Group 1 hearts (N = 8) received hypothermic crystalloid cardioplegic solution, and were harvested and stored at 4 degrees C in balanced electrolyte solution for six hours prior to transplantation. Group 2 (N = 9) received identical treatment with the addition of 30,000 units of superoxide dismutase to the cardioplegic solution and the administration of 60,000 units of superoxide dismutase coincident with reperfusion. All animals were weaned from cardiopulmonary bypass. Preischemic and postischemic LV function was determined using sonomicrometry and a micromanometer-tipped LV catheter. Coronary blood flow was determined using standard microsphere techniques, and platelet deposition was assayed with autologous platelets labeled with indium 111. Lipid peroxidation products were measured using thiobarbituric acid assay. LV performance was significantly better (p less than .05) in Group 2 hearts when assessed by the slope of the end-systolic pressure-volume relationship and the stroke work versus end-diastolic volume relationship. There was better preservation of endocardial blood flow in the group receiving superoxide dismutase compared with controls (p less than .05). Platelet deposition, as determined by the tissue to blood ratio of scintigraphic counts, was greater (p less than .05) in controls compared with the group receiving superoxide dismutase. In addition, thiobarbituric acid reactive species were significantly less (p less than .05) in Group 2 versus Group 1 hearts.(ABSTRACT TRUNCATED AT 250 WORDS)


The Annals of Thoracic Surgery | 1995

MRI Complements Standard Assessment of Right Ventricular Function After Lung Transplantation

William H. Frist; Christine H. Lorenz; Eloisa S. Walker; James E. Loyd; James R. Stewart; Thomas P. Graham; Daryl P. Pearlstein; Steven P. Key; Walter H. Merrill

BACKGROUNDnChanges in right ventricular mass and ejection fraction after single-lung transplantation for pulmonary hypertension are poorly understood.nnnMETHODSnTo complement functional data provided by echocardiography, radionuclide ventriculography, and right heart catheterization, magnetic resonance imaging was used to assess right ventricular function in 5 single-lung transplant recipients with preoperative pulmonary hypertension and right ventricular dysfunction (right ventricular ejection fraction, 0.21 +/- 0.09). The right and left ventricular mass, ejection fraction, and mass ratio (left ventricular mass/right ventricular mass) were calculated from the magnetic resonance images.nnnRESULTSnThe mean pulmonary artery pressure fell from 72 +/- 18 to 21 +/- 8 mm Hg after transplantation. At 3 months after transplantation both the left ventricular and right ventricular ejection fractions approached normal values, as shown by both radionuclide ventriculography and magnetic resonance imaging, but the right ventricular mass remained abnormally high with slightly low mass ratios. By 1 year both the left ventricular and right ventricular masses had regressed to normal with near-normal mass ratios.nnnCONCLUSIONSnRight ventricular performance returns to nearly normal early after transplantation, but the right ventricular mass regresses over a more prolonged time. Cine magnetic resonance imaging provides a noninvasive means of assessing changes in right ventricular function and mass after lung transplantation.


The Annals of Thoracic Surgery | 1994

Operative risk factors and durability of repair of coarctation of the aorta in the neonate

Walter H. Merrill; Steven J. Hoff; James R. Stewart; Charles C. Elkins; Thomas P. Graham; Harvey W. Bender

The risk factors for the operative mortality and long-term durability of repair after surgical correction of coarctation of the aorta in neonates remain controversial. Between January 1970 and January 1993, 139 patients under 1 month of age underwent repair of coarctation of the aorta. Complex intracardiac defects were present in 59 patients. Another 44 patients had an associated ventricular septal defect. Subclavian artery flap repair was performed in 92 patients; end-to-end anastomosis (38 patients) and patch angioplasty (9 patients) were performed less commonly. The hospital mortality was significantly higher in patients with complex intracardiac defects (9 of 59 patients; 15.2%) than in those with a ventricular septal defect (1 of 44 patients; 2.3%) or with isolated coarctation (none of 36 patients; p = 0.007). Elevated pulmonary artery diastolic pressure (p = 0.041) and complex intracardiac anomalies (p = 0.048) were found to be independent predictors of hospital mortality. The presence of a complex cardiac defect (p < 0.001) was an independent predictor of poor long-term survival. Recurrent stenosis requiring reoperation had occurred or balloon dilation had been necessary in 27.9% of the children at 5 years postoperatively. In patients followed up for at least 5 years, the recurrence-free survival was better in those who had undergone subclavian artery flap repair than in those who had undergone end-to-end repair (p = 0.017). When coarctation of the aorta must be repaired in the neonate, operative mortality and long-term survival are affected by the complexity of associated intracardiac anomalies.(ABSTRACT TRUNCATED AT 250 WORDS)

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Harvey W. Bender

Vanderbilt University Medical Center

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John W. Hammon

Vanderbilt University Medical Center

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James B. Atkinson

Vanderbilt University Medical Center

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Thomas P. Graham

Vanderbilt University Medical Center

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Edward B. Gerhardt

Vanderbilt University Medical Center

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Martin P. Sandler

Vanderbilt University Medical Center

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