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Biomedical subjects

D B Doty

Publications and source records attributed to D B Doty.

At least 19 recordsLinked to original sources
PubMed1999

Superior vena cava obstruction: bypass using spiral vein graft.

BACKGROUND: Previous midterm experience with the composite spiral saphenous vein graft to bypass the obstructed superior vena cava (SVC) has been favorable. This study looks at the long-term results in patients followed for up to 23 years. METHODS: Sixteen patients aged 17 to 68 years had operation for obstruction of the SVC with SVC syndrome caused by benign disease. Eleven patients had fibrosing mediastinitis with or without caseous necrosis, 4 had thrombosis caused by a catheter or a pacemaker electrode, and 1 had spontaneous thrombosis. All operations were performed using a composite spiral vein graft constructed from the patient's own saphenous vein. Graft diameter ranged from 9.5 to 15.0 mm. Ten grafts were from the left innominate vein, and six grafts were from the right or left internal jugular vein. The grafts were placed to the right atrial appendage in all patients except 1. Follow-up extends from 1 month to 23 years 8 months (mean follow-up, 10.9 years). RESULTS: Fourteen of 16 grafts remain patent for up to 23 years, and all patients but 1 are free from SVC syndrome. One patient required revision of the graft for thrombosis 4 days after operation. Two grafts closed during the first year after operation: one because of recurrence of spontaneous venous thrombosis and the other because of aggressive fibrosing mediastinitis requiring operation for graft revision three times over a 12-year period prior to death. CONCLUSIONS: These data demonstrate that a spiral vein bypass graft for treatment of the obstructed SVC relieves SVC syndrome and has excellent long-term patency.

Adolescent↗
PubMed1998

Full-spectrum cardiac surgery through a minimal incision: mini-sternotomy (lower half) technique.

A technique is described in which most, if not all, cardiac operations may be performed through a standard small incision. A midline, lower half sternotomy is used. This provides traditional exposure of the heart and allows the surgeon to directly visualize the operating field and use familiar instruments. The complete spectrum of coronary revascularization and cardiac valve operations has been performed through this less-invasive incision.

Cardiac Surgical Procedures↗
PubMed1998

Cardiopulmonary response to maximal exercise in young athletes following the Ross procedure.

BACKGROUND: Aortic prosthetic devices offer limitations that make them less than optimal valve substitutes because the vast majority are innately obstructive, especially at increased levels of hemodynamic function. The present study is designed to demonstrate the hemodynamics of the pulmonary autograft in 11 conditioned athletes who have undergone the Ross (pulmonary autograft) procedure. Data was compared to a group of 13 age-matched "normal athletes." METHODS: All the Ross athletes had undergone the autograft procedure using the root replacement technique and were at least 3 months into their postrecovery phase. All athletes (both normal and Ross) underwent resting transthoracic echo followed by maximal exercise stress test (modified Bruce protocol) to exhaustion. Post-operative transesphogeal echocardiogram obtained within 90 seconds documented aortic valve gradient and velocity across the aortic valve. RESULTS: In the Ross athlete group, maximum heart rate was 188 beats per minute, peak aortic valve gradient at rest (mm Hg) 7.69 (mean), velocity across the aortic valve at rest (cm per second) 129.40 (mean), peak aortic valve gradient at maximal exercise (mm Hg) 16.30 (mean), velocity across the aortic valve at maximal exercise (cm per second) 190.00 (mean). In the normal athlete group, maximum heart rate was 176 beats/minute, peak aortic valve gradient at rest (mm Hg) 5.97 (mean), velocity across the aortic valve at rest (cm per second) 120.54 (mean), peak aortic valve gradient at maximal exercise (mm Hg) 14.61 (mean), velocity across the aortic valve at maximal exercise (cm per second) 190.23 (mean). CONCLUSION: The pulmonary autograft exhibits hemodynamic characteristics similar to the normal human aortic valve under conditions of enhanced cardiac output.

Aortic Valve↗
PubMed1998

Mitral valve replacement with homograft.

The technique for replacement of the mitral valve with a mitral valve homograft is described. Principles include side-by-side approximation of the papillary muscles using multiple stitches of fine monofilament suture, direct attachment of the annulus of the mitral homograft to the annulus of the patient, and support of the repair by remodeling annuloplasty ring.

Cardiac Surgical Procedures↗
PubMed1998

Aortic valve replacement with cryopreserved aortic allograft: ten-year experience.

OBJECTIVE: Cryopreserved aortic allograft can be used for aortic valve replacement in congenital, rheumatic, degenerative, and infected native valve conditions, as well as failed prosthetic valves. This study was conducted to determine the long-term results of aortic valve replacement with cryopreserved aortic allografts. METHODS: Aortic valve replacement with cryopreserved aortic allografts was performed in 117 patients from July 1985 until August 1996. All patients requiring aortic valve replacement regardless of valve disease were considered for allograft replacement; the valve was preferentially used in patients under age 55 years and in the setting of bacterial endocarditis. Four operative techniques involving cryopreserved aortic allografts were used: freehand aortic valve replacement with 120-degree rotation, freehand aortic valve replacement with intact noncoronary sinus, aortic root enlargement with intact noncoronary sinus, and total aortic root replacement. Valve function was assessed by echocardiography during the operation in 78 patients (66%) and after the operation in 77 patients (65%). RESULTS: One-hundred eighteen aortic valve replacements with cryopreserved aortic allografts were performed on 117 patients; mean age was 45.6 years (range 15 to 83 years) and mean follow-up was 4.6 years (range up to 11 years). Intraoperative echocardiography disclosed no significant aortic valve incompetence. There were four operative deaths (3%) and seven late deaths; freedom from valve-related mortality at 10 years was 9:3% +/- 4.55%. New York Heart Association functional status at latest follow-up was normal in 98 (94%) patients. On postoperative echocardiography, 90% had no or trivial aortic valve incompetence. Freedom from thromboembolism at 10 years was 100% and from endocarditis, 98% +/- 2.47%. Seven (6%) patients required valve explantation, four for structural deterioration. At 10 years, freedom from reoperation for allograft-related causes was 92% +/- 3.47%. CONCLUSIONS: Aortic valve replacement with cryopreserved aortic allografts can be performed with low perioperative and long-term mortality. Most patients have excellent functional status, and reoperation for valve-related causes is unusual. Aortic valve replacement with cryopreserved aortic allografts demonstrates excellent freedom from thromboembolism, endocarditis, and progressive valve incompetence.

Adolescent↗
PubMed1998

Aortic valve replacement with medtronic freestyle bioprosthesis: operative technique and results.

OBJECTIVE: This study evaluates the initial results for safety and efficacy of aortic valve replacement (AVR) using the Medtronic Freestyle Bioprosthesis. METHODS: One hundred three patients underwent AVR with the Medtronic Freestyle Bioprosthesis over a 40-month period. There were 59 male and 44 female patients with a mean age of 74 years (range 36 to 88 years). Valve size ranged from 19 to 27 mm, and all valves were implanted using a freehand subcoronary technique. Anticoagulation with coumadin was only used for atrial fibrillation. Aspirin was given to patients with associated coronary artery disease. Echocardiography to assess transvalvular pressure gradient and effective valve orifice area was performed at discharge, 3 to 6 months, 1 year, and then annually. RESULTS: There were 4 (3.9%) deaths within 30 days of operation and 5 (4.9%) late deaths. Two (1.9%) deaths were valve-related, one from commissural dehiscence and one from bacterial endocarditis. Three (2.9%) deaths, two early and one late, were from other cardiac causes. The remaining deaths were from noncardiac causes. Five (4.9%) patients suffered a thromboembolic event, two had permanent neurological deficits, two had transient neurological events, and one had coronary artery occlusion. Mean transvalvular gradient assessed by echocardiography was low at all time intervals: discharge (12.8 mmHg), 3 to 6 months (11.3 mmHg), 1 year (12.0 mmHg), and 2 years (11.6 mmHg). Mean effective valve orifice area was good at all time intervals: discharge (1.4 cm2), 3 to 6 months (1.5 cm2), 1 year (1.6 cm2), and 2 years (1.6 cm2). Of the 38 patients assessed by echocardiography at 1 year, 33 (87%) had no or trivial valve incompetence and the remainder had mild valve incompetence. CONCLUSIONS: Aortic valve replacement with the Medtronic Freestyle Bioprosthesis has a low incidence of early valve-related mortality and thromboembolism. The bioprosthesis demonstrates good hemodynamic performance even in small diameters and is particularly well suited for older patients and the small aortic root.

Adult↗
PubMed1996

Pulsatile augmentation device for extracorporeal circulation.

A device has been designed, constructed, and tested to provide pulsatile pressure/flow to a standard extracorporeal bypass circuit. The pulsatile augmentation device is pneumatically driven similar to an artificial heart ventricle except that there are no valves. It is constructed of polyurethane by vacuum forming and high frequency welding. Drivers used are a modified Arrow-Kontron intraaortic balloon pump or the Utah artificial heart driver. In vitro testing with fresh bovine blood demonstrated acceptable blood compatibility and hemodynamic function. In vivo testing for 4 h in a right and left heart extracorporeal bypass circuit showed good pulse augmentation in pulmonary and systemic bypass circuits. The device shows promise for adding pulse to standard cardiopulmonary bypass and to extracorporeal right heart circulatory assist circuits.

Animals↗
PubMed1996

Aortic valve replacement with homograft and autograft.

The aortic valve may be replaced with an aortic homograft or a pulmonary autograft in children and young adults. The risk of surgery is low (2.5%). No anticoagulants are required, and thromboembolism is virtually unknown unless valve degeneration or endocarditis occur. Late follow-up indicates that approximately 85% of patients will be free of reoperation at 10 years when an aortic homograft is used and at 20 years when a pulmonary autograft is used.

Adult↗
PubMed1996

Improved long-term survival after heart transplantation predicted by successful early withdrawal from maintenance corticosteroid therapy.

BACKGROUND: Short-term studies suggest that cardiac transplant immunosuppression without maintenance corticosteroids is feasible in selected patients. However, concern exists as to the long-term effects, specifically the possibility of increased morbidity and mortality because of late allograft rejection and allograft coronary artery disease. METHODS: We retrospectively reviewed the records from 441 consecutive heart transplantation procedures done in 416 patients with use of an immunosuppressive protocol that attempted corticosteroid withdrawal within 2 months of transplantation. forty-two patients died or underwent retransplantation during the first 3 months and were excluded from further analysis. Analysis focused on demographic and long-term outcome variables (including death, rejection, retransplantation, and infection). RESULTS: Thirty percent (111) of eligible patients (374) met the definition of successful early steroid withdrawal. Only male gender independently predicted successful withdrawal. Mortality, both short and long term, was significantly lower in patients in whom successful early withdrawal from corticosteroids was achieved than in patients in whom the early attempts failed (1.7% per year versus 4.7% per year; p < 0.0001). The prevalence of late acute allograft rejection (more than 1 year after transplantation) was lower in patients successfully withdrawn from steroid therapy early after transplantation (0.07 pt-yr of follow-up versus 0.15 pt-yr; p = 0.002). Multivariate analysis of the entire group identified incidence of infection (p = 0.001), older age (p = 0.001), failed early steroid withdrawal (p = 0.006), and female gender (p = 0.016) as independent predictors of mortality. CONCLUSIONS: Successful early corticosteroid withdrawal identifies a subgroup of "immunologically privileged" patients with a low risk for long-term mortality and is not associated with an increased prevalence of late rejection or clinically significant coronary artery disease.

Case-Control Studies↗
PubMed1995

Long-term follow-up of extended aortoplasty for supravalvular aortic stenosis.

Extended aortoplasty is an operation that was designed to provide a symmetric reconstruction of the aortic root in patients with supravalvular aortic stenosis. The aim of this report is to provide long-term follow-up of the original cohort of 15 patients who underwent extended aortoplasty between 1975 and 1983. Follow-up was obtained in 14 patients. One patient was lost to follow-up 3 years after operation; he was included in this report. An echocardiogram, chest radiograph, and electrocardiogram were obtained for each surviving patient. The median length of follow-up was 141 months (range 36 to 238). The median preoperative gradient was 90 mm Hg (range 55 to 150). The median immediate postoperative gradient was 20 mm Hg (range 0 to 50, p < 0.05 compared with preoperative gradient) and the median long-term gradient was 32 mm Hg (range 6 to 96, p < 0.05 compared with preoperative gradient; p = not significant compared with immediate postoperative gradient). Two patients died: one of left ventricular failure after a subsequent aortic valve replacement and one of chronic left ventricular failure. The Kaplan-Meier estimate of survival at 218 months for all patients was 77.4% (70% confidence limits 62% to 93%). The estimated freedom from reoperation for all patients was 69% at 218 months (70% confidence limits 56% to 82%). Univariate analysis revealed that the presence of a bicuspid valve is a significant risk factor for reoperation (p = 0.038), but not for death (p = 0.51). The Kaplan-Meier estimate of freedom from reoperation for patients with a bicuspid aortic valve was 42.9% at 141 months (70% confidence limits 21% to 65%). Extended aortoplasty provides effective long-term relief of the pressure gradient across the supravalvular ridge. However, a significant number of patients require subsequent operations, particularly those with a bicuspid aortic valve.

Adolescent↗
PubMed1994

Early and intermediate results of the Fontan procedure at moderately high altitude.

At higher elevations, alveolar hypoxia increases pulmonary vascular resistance and may limit the cardiac output of individuals without a subpulmonary ventricle. Thus, we reviewed the outcome of definitive palliation for tricuspid atresia and other forms of single ventricle in 60 consecutive Fontan patients living at a mean elevation of 1,370 m (range, 910 to 2,130 m). There were four early deaths (6.7%; 70% confidence limits, 4.1% to 10.7%) and six late deaths. Kaplan-Meier actuarial survival (+/- standard error) is 79.6% +/- 8.2% at 5 years. Survival was significantly decreased in patients with a preoperative mean pulmonary arterial pressure greater than or equal to 15 mm Hg unless the Fontan procedure was performed with a residual fenestration. Exercise tolerance was significantly worse at higher elevations in a subgroup of patients who have traveled to altitudes of 1,680 to 3,350 m. We conclude that the early and intermediate results of the Fontan procedure at moderately high altitude are similar to results reported at sea level. However, exercise tolerance may be impaired at higher elevations in many patients.

Adolescent↗
PubMed1994

Hypothermic circulatory arrest for cardiac valve replacement reoperations.

Three patients had cardiac valve replacement using hypothermic circulatory arrest. The patients had multiple previous operations via median sternotomy, and 1 had functioning coronary bypass grafts. This technique provided simple and safe reentry to the heart without necessity of control of the aorta or venae cavae, adequate myocardial and cerebral protection from ischemia, and excellent operating conditions for the valve replacement.

Adult↗
PubMed1994

Aortic valve prosthesis obstruction after aortoventriculoplasty: reconstruction with aortic allograft.

An aortoventriculoplasty (Konno procedure) operation was performed for relief of tunnel-type subaortic stenosis using a Bjork-Shiley valve aortic prosthesis. The mechanical prosthesis thrombosed and cerebral embolism occurred when anticoagulant medication was stopped. The aortic root was successfully reconstructed with a cryopreserved aortic allograft using freehand implant technique. The cryopreserved aortic allograft is an excellent replacement device in the young adult patient in cases of failed prostheses, even in the presence of complex left ventricular outflow tract morphology or previous reconstruction operations.

Adult↗
PubMed1994

Replacement of the aortic valve with cryopreserved aortic allograft: the procedure of choice for young patients.

The results of replacement of the aortic valve with cryopreserved aortic allograft are reviewed. There were no operative deaths in 88 patients. Thromboembolism did not occur in any patient and no anticoagulant medications were used. Actuarial freedom from reoperation for any reason was 89%; for structural deterioration it was 93% at 7.5 years. Infection was cured in all patients with endocarditis. Aortic allografts may be inserted by: (1) 120 degrees rotation freehand technique; (2) intact noncoronary sinus freehand technique; (3) aortic root enlargement technique; and (4) aortic root replacement technique. Zero thromboembolism without anticoagulants, high rate of cure of endocarditis, and the versatility of the tissue with a variety of methods for insertion to rebuild and remodel the aortic root to provide normal hemodynamic characteristics make aortic allograft the device of choice for replacement of the aortic valve in young patients.

Adult↗
PubMed1993

Replacement of the aortic valve with cryopreserved aortic allograft.

Replacement of the aortic valve with cryopreserved aortic allograft was performed in 88 patients during the period from July 1985 until January 1993. Age of patients ranged from 15 to 75 years (mean, 44 years). The cause of aortic valve disease was congenital in 39 (44%), rheumatic in 9 (10%), degenerative in 14 (16%), endocarditis in 11 (13%), and failed prosthesis in 15 (17%). The operation was performed by freehand allograft technique in 71 patients (81%). There were no perioperative deaths. Two patients died later at 4 months and 5 years after operation (actuarial survival = 94% at 7.5 years). Follow-up extending to 7.5 years shows 87% of patients are in New York Heart Association functional class I. No thromboembolism has been detected in any patient. Infection was cured in all patients with endocarditis. Mild aortic valve incompetence was detected by diastolic murmur in 45% of patients. Only three valves have been removed at reoperation: one was removed early for technical reasons, and two valves were removed for structural degeneration at 33 and 55 months; the latter was infected. Actuarial freedom from reoperation for any reason was 89%; for structural deterioration it was 93% at 7.5 years. Aortic valve replacement with cryopreserved aortic allograft can be safely performed in adult patients. Medium-term results show excellent freedom from thromboembolism and cure of bacterial endocarditis. Mild aortic valve incompetence is often present, but reoperation for progressive incompetence is unusual.

Actuarial Analysis↗
PubMed1993

Aortic valve replacement and mitral valve repair with allograft.

Techniques of repair of defects in the anterior leaflet of the mitral valve and replacement of the aortic valve using allograft are presented. The case history and operative procedure of a reconstructive operation that did not require anticoagulant therapy after surgery are described for three adult patients. Mitral valve defects were repaired using the anterior leaflet of the mitral valve of the allograft. The aortic valve or entire root was replaced with the aortic allograft. The aortic/mitral allograft should be considered as an alternative to replacement of the aortic and mitral valves with prostheses in selected patients.

Adult↗
PubMed1993

Aneurysm of the left atrium.

A case of aneurysm of the body of the left atrium is reported. Diagnosis of this condition should be considered in patients presenting with supraventricular tachyarrhythmia and a mass on the left side of the heart. Surgery to remove the aneurysm is the treatment of choice.

Adult↗