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Biomedical subjects

Bruce W Lytle

Publications and source records attributed to Bruce W Lytle.

At least 55 records · Page 3Linked to original sources
PubMed2004

Elephant trunk procedure: newer indications and uses.

BACKGROUND: The elephant trunk procedure is used for extensive aortic aneurysms. We evaluated its safety, newer indications, and influence of second-stage completion on survival. METHODS: Records were reviewed for 94 consecutive patients (age 67 +/- 11 years, 47% men) who underwent the procedure between November 1990 and February 2003. The trunk was implanted as an extension of the ascending aorta and arch graft in 83 of 94 (88.3%) patients, distal arch graft in 8 of 94 (8.5%) patients, and in 3 distal to the left subclavian artery (3 of 94 patients [3.2%]). Aortic dissection was present in 37 (39.4%) patients and Marfan syndrome was present in 7 (7.4%). Twenty-three were reoperations (24.5%). In 9 patients, the trunk procedure was adjunctive in preparation for the second operation. In 15 patients, the anastomosis was completed between the left subclavian and common carotid arteries. Coronary artery bypass was performed in 36 (38.4%) and aortic valve operation in 55 (58.5%; 20 root sparing repairs, 16 composite grafts and 19 replacements) patients. RESULTS: There were two early 30-day in-hospital deaths (2.1%) and 5 permanent strokes (5.3%). Eleven died before the second-stage procedure. Forty-seven (57%) underwent second-stage procedures; 40 by thoracotomy and 7 by stent graft insertion, including 2 thoracoabdominal aneurysm repairs with visceral bypasses before stent grafting with 4 early deaths (8.5%). Five-year survival was 34% without a second-stage procedure versus 75% 3-year survival with it. CONCLUSIONS: With a current total of 142 elephant trunk procedures, we found it is safe and should be used more with initial cardiac surgery before descending or thoracoabdominal aorta repair.

Aged↗
PubMed2004

Does the arterial cannulation site for circulatory arrest influence stroke risk?

BACKGROUND: We investigated whether axillary/subclavian artery inflow with a side graft decreases the risk of stroke versus cannulation at other sites during hypothermic circulatory arrest. METHODS: Between January 1993 and May 2003, 1,352 operations with circulatory arrest were performed for complex adult cardiac problems. A single arterial inflow cannulation site was used in 1,336 operations, and these formed the basis for comparative analyses. Cannulation sites were axillary plus graft in 299 operations, direct cannulation of the aorta in 471, femoral in 375, innominate in 24, and axillary or subclavian without a side graft in 167. Retrograde brain perfusion was used in 933 (69%). A total of 272 (20%) were for emergencies, 432 (32%) were reoperations, and 439 (32%) were for dissections. A total of 617 (46%) had aortic valve replacement and 1,160 (87%) ascending, 415 arch (31%), and 248 descending (18%) aortic replacements. Indications also included arteriosclerosis (n = 301) and calcified aorta (n = 278). Primary comparisons were made by using propensity matching, and, secondarily, risk factors for stroke or hospital mortality were identified by multivariable logistic regression. RESULTS: Stroke occurred in 6.1% of patients (81/1,336): 4.0% (12/299) of those had axillary plus graft and 6.7% who had direct cannulation (69/1,037; p = 0.09; p = 0.05 among propensity-matched pairs). Operative variables associated with stroke included direct aortic cannulation, aortic arteriosclerosis, descending aorta repair, and mitral valve replacement. The risk of hospital mortality was higher (11%; 42/375) for patients who had femoral cannulation than axillary plus graft (7.0%; 21/299; p = 0.06; p = 0.02 among propensity-matched pairs). CONCLUSIONS: Axillary inflow plus graft reduces stroke and is our method of choice for complex cardiac and cardioaortic operations that necessitate circulatory arrest. Retrograde or antegrade perfusion is used selectively.

Aged↗
PubMed2004

The effect of bilateral internal thoracic artery grafting on survival during 20 postoperative years.

BACKGROUND: To compare survival of patients receiving bilateral internal thoracic artery grafts and single internal thoracic artery grafts more than 20 postoperative years, assess magnitude of benefit, and identify predictors of benefit. METHODS: From cohorts of 8123 patients receiving single internal thoracic artery grafts and 2001 receiving bilateral internal thoracic artery grafts during primary isolated bypass operations for multivessel coronary disease between 1971 and 1989, we identified 1152 propensity-matched pairs. Mean follow-up of survivors was 16.5 years, with 51 patients followed for 20 years or more. Hazard function methodology was used to identify risk factors for mortality, compare survival, and assess magnitude of benefit. RESULTS: Comparison of the matched pairs showed survival of the bilateral internal thoracic artery and single internal thoracic artery groups at 7, 10, 15, and 20 years was 89% versus 87%, 81% versus 78%, 67% versus 58%, and 50% versus 37%, respectively (p < 0.0001). Divergence of bilateral internal thoracic artery and single internal thoracic artery hazard function curves continued to widen through 20 postoperative years. At 20 years, bilateral internal thoracic artery grafting was predicted to produce worse survival in 2.8% of patients, a survival advantage of less than 5% in 12.9%, greater than 10% in 52%, and greater than 15% in 7.6%. Combinations of cardiac and noncardiac descriptors were used to define higher and lower risk patient subsets. Advanced age, abnormal left ventricular function and noncardiac risk factors decreased overall survival but the incremental benefit of bilateral internal thoracic artery grafting persisted. CONCLUSIONS: Bilateral internal thoracic artery grafting produces improved survival compared with single internal thoracic artery grafting during the second postoperative decade, and the magnitude of that benefit increases through 20 postoperative years.

Coronary Disease↗
PubMed2004

Aortic dissection after previous cardiovascular surgery.

BACKGROUND: Risk of repairing aortic dissection after previous cardiovascular surgery has not been described clearly. This study assesses early and late outcomes of such reoperations. METHODS: From January 1, 1990, to January 1, 2002, 108 patients with prior cardiovascular surgery (isolated coronary artery bypass grafting, 51%; isolated valve surgery, 21%; aortic aneurysm repair, 24%; and combinations of these in the remainder) underwent reoperation for aortic dissection (emergency operation for acute dissection in 24%). Mean age was 63 +/- 13 years, and 85% were men. The interval since prior surgery ranged from 10 days to 22 years (median, 3.8 years). This was the third operation for 8%. Ascending aortic repair with or without aortic arch or descending aortic repair was performed in 40%, aortic valve replacement (n = 15) or repair (n = 17) with ascending aortic repair in 30%, aortic root replacement with or without aortic arch or descending aortic repair in 30%, and aortic arch with or without descending aortic repair in 1%. Circulatory arrest was used in 78%, with retrograde brain perfusion in 58%. RESULTS: Hospital mortality was 6%, stroke 4%, renal failure 2%, and respiratory failure 7%. Survival at 30 days and 1, 3, 5, and 7 years was 93%, 85%, 74%, 63%, and 53%, respectively. Aortic reoperation was performed in 7 patients, with freedom from this event at 30 days and 1, 3, 5, and 7 years of 98%, 95%, 93%, 91%, and 89%., respectively CONCLUSIONS: Aortic dissection after cardiovascular surgery is rare and can be managed with acceptable operative risks and good long-term survival. Need for subsequent aortic reoperation is uncommon.

Aged↗
PubMed2004

Equivalent midterm outcomes after off-pump and on-pump coronary surgery.

OBJECTIVE: Multiple reports demonstrate that off-pump surgery reduces the early morbidity associated with coronary artery bypass grafting. To determine if there are any differences in later outcomes, we compared midterm results of propensity-matched patients who underwent off- and on-pump coronary artery bypass grafting. METHODS: From January 1997 to July 2000, 481 patients underwent off-pump coronary artery bypass grafting and 3231 underwent on-pump coronary artery bypass grafting. Propensity matching was used to match 406 patients from each group. Previously, the propensity-matched off-pump patients were found to have had significantly fewer bypass grafts. These 812 patients were followed for time-related events, including death, myocardial infarction, percutaneous coronary intervention, coronary reoperation, and the combined end point of all-cause mortality, myocardial infarction, and all coronary reintervention. Follow-up was 95% complete. RESULTS: At 4 years, survival was 87.5% after off-pump and 91.2% after on-pump coronary artery bypass grafting (P =.2); freedom from myocardial infarction was 92.6% and 95.7% (P =.7), respectively; freedom from percutaneous coronary intervention was 94.3% and 95.5% (P =.9), respectively; freedom from coronary reoperation was 98.1% and 99.0% (P =.4), respectively; and freedom from the combined end point of all-cause mortality, myocardial infarction, and coronary reintervention was 75.2% and 82.9% (P =.14), respectively. CONCLUSIONS: Off-pump and on-pump coronary artery bypass grafting results in equivalent midterm outcomes. Fewer bypass grafts in the off-pump patients did not decrease survival or increase ischemic events at 4 years.

Aged↗
PubMed2004

Tricuspid valve repair: durability and risk factors for failure.

OBJECTIVES: To compare durability of tricuspid valve annuloplasty techniques, identify risk factors for repair failure, and characterize survival, reoperation, and functional class of surviving patients. METHODS: From 1990 to 1999, 790 patients (mean age 65 +/- 12 years, 51% New York Heart Association functional class III or IV, and mean right ventricular systolic pressure 56 +/- 18 mm Hg) underwent tricuspid valve annuloplasty for functional regurgitation using 4 techniques: Carpentier-Edwards semi-rigid ring, Cosgrove-Edwards flexible band, De Vega procedure, and customized semicircular Peri-Guard annuloplasty. Of these patients, 89% had concomitant mitral valve surgery. A total of 2245 follow-up transthoracic echocardiograms were retrieved. Tricuspid regurgitation was analyzed, and risk factors for worsening regurgitation were identified, by multivariable ordinal longitudinal methods. RESULTS: Tricuspid regurgitation 1 week after annuloplasty was 3+ or 4+ in 14% of patients. Regurgitation severity was stable across time with the Carpentier-Edwards ring (P =.7), increased slowly with the Cosgrove-Edwards band (P =.05), and rose more rapidly with the De Vega (P =.002) and Peri-Guard (P =.0009) procedures. Risk factors for worsening regurgitation included higher preoperative regurgitation grade, poor left ventricular function, permanent pacemaker, and repair type other than ring annuloplasty. Right ventricular systolic pressure, ring size, preoperative New York Heart Association functional class, and concomitant surgery were not risk factors. Tricuspid reoperation was rare (3% at 8 years), and hospital mortality after reoperation was 37%. CONCLUSIONS: Tricuspid valve annuloplasty did not consistently eliminate functional regurgitation, and across time regurgitation increased importantly after Peri-Guard and De Vega annuloplasties. Therefore, these repair techniques should be abandoned, and transtricuspid pacing leads should be replaced with epicardial leads.

Aged↗
PubMed2004

Recurrent mitral regurgitation after annuloplasty for functional ischemic mitral regurgitation.

OBJECTIVES: We sought to characterize the temporal return of mitral regurgitation after annuloplasty for functional ischemic mitral regurgitation; to identify its predictors, particularly with respect to annuloplasty type; and to determine whether annuloplasty type influences survival. METHODS: From April 1985 through November 2002, 585 patients underwent annuloplasty alone for repair of functional ischemic mitral regurgitation, generally with concomitant coronary revascularization (95%). A flexible band (Cosgrove) was used in 68%, a rigid ring (Carpentier) in 21%, and bovine pericardial annuloplasty (Peri-Guard) in 11%. Six hundred seventy-eight postoperative echocardiograms were available in 422 patients to assess the time course of postoperative mitral regurgitation and its correlates. Most echocardiograms were performed early after the operation (median, 8 days); 17% were performed at 1 year or beyond. RESULTS: During the first 6 months after repair, the proportion of patients with 0 or 1+ mitral regurgitation decreased from 71% to 41%, whereas the proportion with 3+ or 4+ regurgitation increased from 13% to 28% ( P < .0001); the regurgitation grade was stable thereafter. The temporal pattern of development of 3+ or 4+ regurgitation was similar for Cosgrove bands and Carpentier rings (25%) but substantially worse for Peri-Guard annuloplasties (66%). Small annuloplasty size did not influence postoperative regurgitation grade ( P = .2), although Cosgrove bands were used in most patients receiving 26- and 28-mm annuloplasties. Freedom from reoperation was 97% at 5 years. Annuloplasty type was not associated with survival. CONCLUSIONS: Although initial mitral valve replacement would eliminate the risk of postoperative mitral regurgitation, this strategy has been associated with reduced survival. Therefore the development of additional techniques is necessary to achieve more secure repair of functional ischemic mitral regurgitation.

Aged↗
PubMed2003

Comparison of left ventricular diastolic function in obstructive hypertrophic cardiomyopathy in patients undergoing percutaneous septal alcohol ablation versus surgical myotomy/myectomy.

Both percutaneous transcoronary alcohol septal reduction (ASR) and surgical myectomy are effective treatments to relieve left ventricular (LV) outflow tract obstruction in obstructive hypertrophic cardiomyopathy (HC). LV diastolic function was assessed by echocardiography in 57 patients with obstructive HC at baseline and 5 +/- 4 months after ASR (n = 37) or surgical myectomy (n = 20). LV outflow tract pressure gradient decreased from 65 +/- 40 to 23 +/- 21 mm Hg (p <0.01) after treatment. The ratio of the early-to-late peak diastolic LV inflow velocities, and the ratio of the early peak diastolic LV inflow velocity to the lateral mitral annulus early diastolic velocity determined by tissue Doppler imaging significantly decreased after the procedures (1.6 +/- 1.7 vs 1.0 +/- 0.7 and 15 +/- 8 vs 11 +/- 5, respectively), whereas LV inflow propagation velocity significantly increased (60 +/- 24 vs 71 +/- 36 cm/s). Left atrial size decreased from 29 +/- 7 to 25 +/- 6 cm(2) (p <0.05). Patients had a significant improvement in New York Heart Association functional class and in exercise performance. When comparing ASR with myectomy, no difference was found in the degree of change in any parameter of diastolic function. Thus, diastolic function indexes obtained by echocardiography changed after septal reduction interventions in patients with obstructive HC; this change was similar to that after surgical myectomy and ASR.

Adolescent↗
PubMed2003

Does competitive flow reduce internal thoracic artery graft patency?

BACKGROUND: In coronary arteries with moderate stenosis, competitive flow may lead to internal thoracic artery (ITA) graft occlusion. The goals of this study were to determine if competitive flow reduces ITA patency, and if there is a degree of coronary stenosis below which ITAs should not be used. METHODS: From 1972 to 1999, 50,278 patients underwent primary coronary artery bypass grafting (CABG). Of these, 2,002 had at least one ITA graft and postoperative angiography before coronary reintervention; 2,999 angiograms of 2,121 ITAs were made. Time-related ITA occlusion was modeled using longitudinal analysis to identify its risk factors while accounting for lack of independence introduced by repeated angiography and multiple ITA anastomoses per patient. Proximal coronary stenosis (maximum preoperative stenosis between ITA anastomosis and aorta) was the surrogate for competitive flow. RESULTS: Unadjusted ITA patency was 93%, 89%, 90%, and 92% at 1, 5, 10, and 15 years after CABG. Risk factors associated with ITA occlusion were lesser degree of proximal coronary stenosis (p < 0.0001); longer time from CABG in grafts to non-left anterior descending coronary arteries (p < 0.0001); female sex (p = 0.0003); later date of CABG (p = 0.01); right ITA (p < 0.0001); and smoking (p < 0.0001). In all arteries, as preoperative proximal coronary stenosis decreased, ITA patency declined; however, at no degree of stenosis was there a sharp decline. CONCLUSIONS: Internal thoracic artery patency decreases as coronary competitive flow increases. However, the nature of this relationship indicates ITAs should not be abandoned at moderate grades of stenosis.

Aged↗
PubMed2003

Mitral valve repair with aortic valve replacement is superior to double valve replacement.

OBJECTIVES: Double valve replacement has been advocated for patients with combined aortic and mitral valve disease. This study investigated the alternative that, when feasible, mitral valve repair with aortic valve replacement is superior. PATIENTS AND METHODS: From 1975 to 1998, 813 patients underwent aortic valve replacement with either mitral valve replacement (n = 518) or mitral valve repair (n = 295). Mitral valve disease was rheumatic in 71% and degenerative in 20%. Mitral valve replacement was more common in patients with severe mitral stenosis (P =.0009), atrial fibrillation (P =.0006), and in patients receiving a mechanical aortic prosthesis (P =.0002). These differences were used for propensity-matched multivariable comparisons. Follow-up extended reliably to 16 years, mean 6.9 +/- 5.9 years. RESULTS: Hospital mortality rate was 5.4% for mitral valve repair and 7.0% for replacement (P =.4). Survivals at 5, 10, and 15 years were 79%, 63%, and 46%, respectively, after mitral valve repair versus 72%, 52%, and 34%, respectively, after replacement (P =.01). Late survival was increased by mitral valve repair rather than replacement (P =.03) in all subsets of patients, including those with severe mitral valve stenosis. After repair of nonrheumatic mitral valves, 5-, 10-, and 15-year freedom from valve replacement was 91%, 88%, and 86%, respectively; in contrast, after repair of rheumatic valves, it was 97%, 89%, and 75% at these intervals. CONCLUSIONS: In patients with double valve disease, aortic valve replacement and mitral valve repair (1) are feasible in many, (2) improve late survival rates, and (3) are the preferred strategy when mitral valve repair is possible.

Adult↗
PubMed2003

Repair versus replacement for degenerative mitral valve disease with coexisting ischemic heart disease.

OBJECTIVE: We sought to compare mitral valve repair and replacement as treatments for degenerative mitral valve disease with coexisting ischemic heart disease. Specifically, we sought to (1) identify differences between patients undergoing repair and replacement, (2) determine whether the choice of mitral valve procedure affected survival after adjusting for those differences, and (3) discover which patients were predicted to benefit from mitral valve repair and which from replacement. METHODS: From 1973 to 1999, 679 patients (mean age, 67 +/- 9.1 years; 73% men) with degenerative mitral valve and ischemic heart diseases underwent combined coronary artery bypass grafting and either mitral valve repair (66%) or replacement (34%). Factors associated with repair and replacement were used for multivariable propensity matching. Risk factors for death were identified by means of multivariable, multiphase hazard-function analysis. RESULTS: Patients more likely to undergo repair had isolated posterior chordal rupture (P <.0001) or more recent date of operation (P <.0001); those more likely to undergo replacement were older (P =.0003) or had bileaflet prolapse (P <.0001). Unadjusted survival at 30 days and 1, 5, and 10 years was 97%, 92%, 79%, and 59% after repair and 94%, 88%, 70%, and 37% after replacement. After adjusting for comorbid factors, the extent and effect of ischemic heart disease, and propensity score, the survival benefit of repair became evident after 2 years (P =.01). Eighty-nine percent of patients were predicted to benefit from repair. CONCLUSIONS: In patients with degenerative mitral valve and ischemic heart diseases, mitral valve repair confers a survival advantage over replacement that becomes evident about 2 years after the operation.

Aged↗
PubMed2002

Association between CK-MB elevation after percutaneous or surgical revascularization and three-year mortality.

OBJECTIVES: The goal of this study was to assess the long-term impact of creatine kinase-MB isoform (CK-MB) elevation after percutaneous or surgical revascularization. BACKGROUND: The long-term impact of CK-MB elevation after coronary artery bypass grafting (CABG) is not as well characterized as that following percutaneous coronary intervention (PCI). METHODS: The three-year cumulative survival of consecutive patients who underwent their first percutaneous or surgical revascularization procedure between January 1, 1995 and August 31, 2000 and had CK-MB determination was assessed using the Social Security Death Index. RESULTS: The 3,812 patients undergoing CABG had a less favorable coronary risk profile than the 3,573 patients undergoing PCI. The incidence of CK-MB elevation above normal range was 90% and 38% for the CABG and PCI groups (p < 0.001). In 6% and 5%, respectively, the elevation surpassed 10x the upper limit of normal (ULN). At an average follow-up of three years, there were 712 deaths, 83 of which occurred within 30 days of procedure. The cumulative survival was 92% and 90% for CABG and PCI, respectively (p = 0.003). Chronic renal insufficiency (adjusted hazard ratio [HR] 3.8, [95% confidence interval 3.1 to 4.6]), age (HR 1.5 per decade [1.3 to 1.6]), ejection fraction <40% (HR 1.3 [1.1 to 1.5] and PCI (HR 1.6 [1.3 to 1.9]) were the main predictors of increased mortality. Creatine kinase-MB isoform elevation only above 10 x ULN was independently predictive of mortality in the CABG (HR 1.3 [1.1 to 1.5]) and PCI (HR 1.1 [1.0 to 1.2]) groups, p < 0.001. CONCLUSIONS: Creatine kinase MB isoform elevation after revascularization is very common, particularly in CABG patients. When extensive, it is independently correlated with increased mortality over a three-year period. Identification and aggressive management of patients with high levels of CK-MB after revascularization may improve their outcome.

Aged↗
PubMed2002

Aortic root replacement with cryopreserved allograft for prosthetic valve endocarditis.

UNLABELLED: BACKGROUND Our strategy has been to treat aortic prosthetic valve endocarditis (PVE) with radical debridement of infected tissue and aortic root replacement with a cryopreserved aortic allograft. This study examines the effectiveness of this strategy on hospital mortality and morbidity, recurrent endocarditis, and survival. METHODS: From 1988 through 2000, 103 patients with aortic PVE underwent root replacement with a cryopreserved aortic allograft. Abscesses were present in 78%, and aortoventricular discontinuity was present in 40%. Thirty-two patients had at least one previous operation for endocarditis. In 23 patients with a history of native valve endocarditis, the allograft was implanted after one episode (17 patients), two episodes (5 patients), or three episodes of PVE (1 patient). In the 80 patients without a history of native valve endocarditis, the allograft was placed after one previous aortic valve replacement (57 patients), two (19), or three (4) previous aortic valve replacements. Among the 92 patients with positive cultures, 52 had staphylococcal organisms, 20 had streptococcal, 6 had fungal, 4 had gram-negative, and 6 had enterococcal organisms. Mean follow-up was 4.3 +/- 2.9 years. RESULTS: Hospital mortality was 3.9%. Permanent pacemakers were required in 31 patients. Survival at 1 year, 2 years, 5 years, and 10 years was 90%, 86%, 73%, and 56%, respectively, with a risk of 5.3% per year after 6 months. Four patients underwent reoperation for recurrent PVE of the allograft (95% freedom from recurrent PVE at > or = 2 years). Risk of recurrent PVE peaked at 9 months and then declined to a low level by 18 months. CONCLUSIONS: A strategy of radical debridement and aortic root replacement with a cryopreserved aortic allograft for aortic PVE is safe, effective, and recommended.

Abscess↗
PubMed2002

Reoperative cryopreserved root and ascending aorta replacement for acute aortic prosthetic valve endocarditis.

BACKGROUND: Prosthetic aortic valve endocarditis (PVE) is an important complication of aortic valve replacement (AVR) and is a particularly difficult situation after an operation combining AVR with ascending aortic replacement. METHODS: From 1988 through 2000, 27 patients with aortic valve PVE after previous ascending aortic replacement (aortic root replacement in 13, aortic valve replacement with a supracoronary graft in 14) underwent reoperation for aortic root replacement with a cryopreserved aortic allograft and prolonged intravenous antibiotic therapy. All patients were considered to have active PVE (25 with positive cultures); root abscess formation was present in 89% and aortoventricular discontinuity in 41%. RESULTS: One patient (3.7%) died in-hospital, and permanent pacemakers were required in 10 patients (37%). Mean postoperative follow-up interval was 3.9 +/- 3.0 years, and survival at 1, 2, 5, and 7.5 years was 92%, 88%, 70%, and 56%, respectively. One patient underwent reoperation for recurrent PVE 8 months after operation. CONCLUSIONS: Radical debridement of infected prosthetic material and tissue, and allograft aortic root and ascending aorta replacement, combined with intravenous antibiotic therapy, appears to achieve a low hospital mortality and a high degree of freedom from recurrent infection for patients with PVE after AVR and ascending aortic replacement.

Abscess↗