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Biomedical subjects

B W Lytle

Publications and source records attributed to B W Lytle.

At least 73 records · Page 4Linked to original sources
PubMed1995

Have PTCA failures requiring emergent bypass operation changed?

From 1980 through 1990, 9,145 patients had balloon angioplasty with failure of the procedure requiring emergent surgical revascularization within 24 hours occurring in 253 patients (2.8%). Patients were divided into two cohorts based on the date of the percutaneous transluminal coronary angioplasty (PTCA): 1980 to 1985 (n = 109) and 1986 to 1990 (n = 144). The incidence of PTCA failure was 3.8% during 1980 to 1985 (109/2,903) and decreased to 2.3% (144/6,242) for 1986 to 1990. Comparison of pre-PTCA patient characteristics between the two periods showed that only a history of a previous PTCA and class III or class IV symptoms were more common in the recent years (p < or = 0.05). In-hospital mortality after emergency operation was 4.6% (5/109) during 1980 to 1985 and 7.6% (11/144) from 1985 to 1990 (p = not significant). This trend toward increased mortality appeared to be related to an increased number of patients who underwent operation in a state of severe hemodynamic compromise in the more recent period. The in-hospital mortality rate for patients in shock or undergoing cardiopulmonary resuscitation was 28.3% (13/46) compared with 1.4% (3/207) for patients with less severe hemodynamic derangement (p < 0.001). Use of the intraaortic balloon pump preoperatively increased from 12.8% to 32.6% (p < 0.01). Late survival was 92% at 2 and 87% at 5 postoperative years. Although the incidence of PTCA failure necessitating emergent surgical intervention has decreased over time, there has been a trend toward an increased in-hospital mortality rate for those patients that does not appear to be related to more severe pre-PTCA characteristics.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1995

Surgical and long-term antifungal therapy for fungal prosthetic valve endocarditis.

BACKGROUND: Fungal prosthetic valve endocarditis is an uncommon but serious disease. We have developed a strategy of treatment that includes perioperative amphotericin B, radical debridement of infected tissue, reconstruction using biologic tissue when possible, and prolonged oral suppressive antifungal therapy. METHODS: We retrospectively reviewed the charts of 12 patients reoperated on for fungal prosthetic valve endocarditis involving the aortic valve (10 patients: six porcine valves, two mechanical valves, two homografts) and the mitral valve (2 patients, both porcine valves). Prosthetic valve endocarditis developed in 7 within 12 months after the first valve procedure. The organisms included Candida species (9 patients), Scopulariopsis brevicaulis (1), Saccharomyces cervisiae (1), and histoplasmosis (1). RESULTS: At operation, all patients had prosthetic vegetations, 8 had abscesses, and 4 had sinus tracts. Seven received aortic homografts, 4 received porcine valves (two mitral), and 1 received a mechanical prosthesis. Two patients died in the hospital after prolonged illnesses (83% hospital survival). Four patients had recurrence an average of 25 months later and 3 underwent further surgical intervention. One patient had recurrence and died 17 months postoperatively. One other late death occurred 96 months after operation, and there was no evidence of recurrence. Eight patients (67%) are alive and well 51.5 +/- 61.0 months (range, 1 to 189 months) after the first redo procedure for fungal prosthetic valve endocarditis. CONCLUSIONS: We conclude that preoperative treatment with amphotericin B, radical resection of all infected tissue, cardiac reconstruction using biologic tissue when possible, and life-long oral antifungal therapy is effective for fungal prosthetic valve endocarditis.

Abscess↗
PubMed1995

Surgical management of hypertrophic obstructive cardiomyopathy. Early and late results.

From 1975 through 1993, 178 patients underwent surgical management of hypertrophic obstructive cardiomyopathy. Operations included isolated septal myectomy (n = 95), septal myectomy and coronary artery bypass grafting (n = 41), septal myectomy plus a valve procedure (n = 25), septal myectomy, valve procedure, and coronary artery bypass grafting (n = 14), and mitral valve replacement without septal myectomy (n = 3). Recent myectomy results were monitored with transesophageal echocardiography. After initial myectomy, 32 patients (20%) underwent a second pump run for more extensive myectomy only (n = 22), mitral valve replacement only (n = 5), or both (n = 2). In-hospital mortality was 6% (n = 11) and 4% (n = 6) for patients undergoing septal myectomy or septal myectomy plus coronary artery bypass grafting, respectively. Heart block occurred in 17 patients (10%). Left ventricular outflow tract systolic gradients decreased from a mean of 93 mm Hg to 21 mm Hg after myectomy. Late survival was 86% and 70% at 5 and 10 postoperative years, respectively, and 93% and 79% for patients undergoing septal myectomy alone or septal myectomy plus coronary artery bypass grafting, respectively. Only 3 of 131 in-hospital survivors of septal myectomy or septal myectomy plus coronary artery bypass grafting died late cardiac deaths, for a yearly mortality of 0.6%. However, the 5-year late survival of patients undergoing valve operation plus septal myectomy was 51%, and multivariate testing confirmed the adverse influence on late survival (p = 0.008), as well as adverse influences of increasing age (p = 0.016) and return to cardiopulmonary bypass for mitral valve replacement (p = 0.038). At follow-up 136 patients (94%) had New York Heart Association class I or II symptoms. For patients with hypertrophic obstructive cardiomyopathy, septal myectomy alone or in combination with coronary artery bypass grafting produces effective symptom relief, excellent long-term survival, and a low risk of late cardiac death.

Aged↗
PubMed1995

The Carpentier-Edwards pericardial aortic valve. Ten-year results.

To evaluate the function of the Carpentier-Edwards pericardial valve in the aortic position, we analyzed the results of 310 aortic valve replacements performed between 1982 and 1985. Mean age was 64.2 +/- 10.8 years (range 22 to 95 years); 190 patients (61.3%) were male patients. There were 18 hospital deaths (5.8%), and none were valve related. Follow-up of the 292 survivors was 100% complete at a mean of 7.8 +/- 2.9 years; 2290 patient-years of follow-up were available for analysis. There were 133 late deaths (45.5%). Actuarial survivals at 5 and 10 years were 82.5% and 45.9%, respectively. The 10-year actuarial freedom from events was 88.7% +/- 2.1% for thromboembolism, 90.9% +/- 1.8% for hemorrhage, 94.3% +/- 1.6% for endocarditis, and 91.2% +/- 2.6% for structural deterioration. The 153 hospital survivors 65 years of age or older had an extremely low incidence of structural valve deterioration, with only four explants and 95.5% actuarial freedom from explantation at 10 years, and a linearized rate of 0.3 +/- 0.2 per patient-year compared with 88.6% and 0.7 +/- 0.2 for patients younger than 65 years of age. Twelve valves were explanted for structural deterioration. Of these, 11 (93%) had leaflet calcification causing stenosis and one had a wear-related leaflet tear. The Carpentier-Edwards pericardial valve has a low incidence of valve-related complications. The freedom from structural valve deterioration is low at 10 years, particularly in patients 65 years of age and older.

Actuarial Analysis↗
PubMed1995

Axillary artery: an alternative site of arterial cannulation for patients with extensive aortic and peripheral vascular disease.

The increasing number of patients with extensive aortic and peripheral vascular atherosclerosis or aneurysms who are undergoing cardiac operations present difficult decisions as to the optimal site of arterial cannulation for cardiopulmonary bypass. Femoral artery cannulation is the most common alternative to ascending aortic cannulation, but severe iliofemoral disease or the danger of atheroemboli caused by retrograde perfusion through an atherosclerotic or aneurysmal descending aorta may make this approach impossible or undesirable. We have used axillary artery cannulation for cardiac operations in 35 patients for indications including severe aortic atherosclerosis (n = 16), extensive aortic aneurysms (n = 11), and aortic dissection (n = 8). The cardiac operations performed were coronary artery bypass grafting (n = 9) aortic valve replacement (n = 1), aortic valve replacement and coronary artery bypass grafting (n = 5), repair of mitral valve periprosthetic leak (n = 1), and resection of ascending and/or aortic arch (n = 19). Deep hypothermia with circulatory arrest was used in 26 patients and retrograde cerebral perfusion in 18. All patients awoke from the operation and no patient had a cerebrovascular accident. One patient required axillary artery thrombectomy and one patient had a mild ipsilateral brachial plexus paresis after the operation. Four patients died in the hospital. We conclude that axillary artery cannulation is a safe and effective means of providing antegrade arterial flow during cardiopulmonary bypass in patients with severe atherosclerotic or aneurysmal disease. This strategy may lower the prevalence of stroke associated with cardiopulmonary bypass in these patients.

Adult↗
PubMed1995

Systemic hypothermia and circulatory arrest combined with arterial perfusion of the superior vena cava. Effective intraoperative cerebral protection.

We have used retrograde arterial perfusion of the superior vena cava as an adjunct to deep hypothermia and systemic circulatory arrest for intraoperative cerebral protection in 43 adult patients (18 of whom were 70 years old or older). The indications for the use of circulatory arrest were thoracic aortic operations (37 patients) and atherosclerosis or calcification of the ascending aorta (6 patients) in patients needing aortic valve or coronary operations. In all patients systemic hypothermia (16 degrees to 18 degrees C) was achieved with cardiopulmonary bypass and the systemic arterial circulation was arrested. Retrograde arterial perfusion of the superior vena cava was established through a wire-reinforced venous cannula (with a superior vena cava tourniquet) at a temperature of 15 degrees C. In 36 patients a separate roller pump system was used for the retrograde cerebral perfusion. Central venous pressure was monitored at 25 to 30 mm Hg; mean flow rate was 250 ml/min. Periods of circulatory arrest and retrograde cerebral perfusion ranged from 4 to 110 minutes (mean 38 minutes), and for seven patients the period of circulatory arrest was longer than 60 minutes. Four postoperative deaths occurred, one related to stroke in a patient who had an aortic dissection during coronary surgery and the others related to noncerebral complications. Three nonfatal cerebral complications occurred, although all had completely resolved by late follow-up. Advantages of retrograde cerebral perfusion are (1) simplicity of use and avoidance of vascular trauma, (2) excellent exposure, (3) retrograde flow that minimizes embolization of air and atherosclerotic debris, and (4) effective cerebral oxygen delivery. Retrograde cerebral perfusion appears to be an important adjunct to hypothermia and circulatory arrest not only for patients undergoing operation for ascending aorta and aortic arch disease but also for patients with diffuse aortic atherosclerosis undergoing coronary or valve operations.

Adult↗
PubMed1995

Surgical treatment of prosthetic valve endocarditis.

Despite advances in the diagnosis and treatment of prosthetic valve endocarditis (PVE) it remains a serious complication of prosthetic valve replacement. Antibiotic treatment alone can be successful for late infections that involve the prosthesis only (particularly for patients with bioprothesis), but it rarely cures infections involving the valve-native annulus interface. Combined antibiotic and surgical treatment of PVE often is successful; more accurate diagnosis (usually based on echocardiography), more effective myocardial protection at reoperation, and improved surgical experience have improved the short-term and long-term outcomes for patients with PVE. For 146 patients of Cleveland Clinic Foundation who underwent reoperation for PVE from 1975 through 1992, the overall in-hospital mortality rate was 13%, 10% from 1985 to 1992. In this more recent surgical period, active infection and early PVE did not appear to be factors that increase in-hospital mortality. The mean in-hospital stay of survivors was 25 days, which highlights the fact that even successful treatment of PVE uses enormous resources. The late survival rate of in-hospital survivors was 82% at 5 years, and the reoperation-free survival rate was 75% at 5 postoperative years.

Anti-Bacterial Agents↗
PubMed1994

Is the internal thoracic artery the conduit of choice to replace a stenotic vein graft?

Reoperative coronary artery bypass grafting secondary to saphenous vein graft (SVG) stenosis is a mushrooming problem. The internal thoracic artery graft (ITA) provides superior long-term patency, but its flow is limited and may be inadequate to meet large myocardial demands. To evaluate the efficacy of the ITA as a replacement conduit for a stenotic SVG, 387 consecutive patients undergoing reoperative bypass grafting from 1985 to 1990 with a stenotic SVG to a totally obstructed left anterior descending coronary artery (LAD) were analyzed. The patients were divided into four groups according to the management of the previously placed SVG. Group I (n = 155) underwent graft replacement with a new SVG. Group II (n = 90) received an ITA with the old SVG left intact. In group III (n = 37), an ITA was placed to the LAD with an SVG to the diagonal (old graft interrupted). Group IV (n = 104) had an ITA only to the LAD (old graft interrupted). There were 14 deaths (3.6%). Mortality rate was 7.9% for group IV and 2.1% for groups I through III (p = 0.01). Multivariate analyses identified advancing age (p = 0.001), ITA only (p = 0.001), and female sex (p = 0.04) as independent predictors of operative mortality. Evidence of hypoperfusion in the distribution of the LAD was present in 19 patients, all of whom were in group IV (18.9%). Predictors of hypoperfusion were moderate/severe left ventricular function (p = 0.02) and ITA to the LAD with interruption of the old graft (p = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Cause of Death↗
PubMed1994

Cardiac reoperation in patients with bilateral internal thoracic artery grafts.

The superior long-term patency of the left internal thoracic artery (ITA) graft is reflected in the enhanced survival of the patients who undergo the procedure, and its use has been shown to lead to a reduced need for reoperation. Evidence is accumulating that use of both ITAs at the primary operation further decreases the need for reoperation, and it is hoped that the use of other arterial conduits will augment this trend. Therefore, the popularity of bilateral ITAs and other arterial conduits in coronary artery operations is growing. However, many surgeons defer using both ITAs at the primary operation partly out of fear of the difficulties that may arise in conjunction with a possible future reoperation. Thirty-six patients underwent reoperation at The Cleveland Clinic Foundation 2 days to 13 years after an earlier bilateral ITA operation because of the progression of native disease, failure of the ITA or vein grafts, or the development of valve disease or end-stage ischemic heart disease. There were four early deaths (11%) and two late deaths, with an average follow-up of 4.3 years (range, 0 to 9.8 years). Forty-seven ITAs were patent preoperatively and 11 crossed the midline. Eleven were patent but stenosed and in need of revision or replacement. Two were damaged during reoperation; both were repaired, but one was ultimately replaced. Although the mortality associated with this procedure is relatively high and these operations are difficult, reoperation can be performed at an acceptable risk, and substantial surgical objectives can be achieved with good long-term results.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗
PubMed1994

Coronary reoperation: results of adding an internal mammary artery graft to a stenotic vein graft.

Although it is desirable at coronary reoperation to replace a stenotic vein graft to the left anterior descending coronary artery (LAD) with an internal mammary artery (IMA) graft, previous reports have shown that if the stenotic vein graft is removed, that strategy can be complicated by severe hemodynamic deterioration and increased perioperative mortality. We report the results for 90 patients in whom an IMA was used to graft a completely obstructed LAD with the stenotic vein graft left intact. For 10 patients, reoperation involved only an IMA-LAD graft, and in 80 patients, a second IMA, veins, or both were used to graft other vessels. There were no hospital deaths. One patient had a perioperative myocardial infarction. Follow-up at a mean postoperative interval of 58 months documented 11 late deaths (eight cardiac related) and actuarial 5-year survival of 88%. Twenty-two patients underwent coronary angiography at a mean postoperative interval of 48 months. The IMA-LAD graft was found to be perfectly patent in 20 and obstructed in 2. The strategy of adding an IMA graft to the LAD and leaving a stenotic vein graft intact has been associated with a low risk of perioperative myocardial infarction, the late clinical results are favorable, and repeat angiography indicates that serious competitive flow from the stenotic vein graft is uncommon.

Adult↗
PubMed1994

Repair of insufficient bicuspid aortic valves.

A technique for the repair of bicuspid aortic valves that includes resection of the flail segment of the prolapsing leaflet, annuloplasty, and resection of the raphe, when present, has been reported. To assess the efficacy of this technique in the repair of insufficient bicuspid aortic valves, the results in 72 consecutive patients were assessed. The mean age of the patients was 39 +/- 11 years; 94% were male. Fifty-six patients (78%) underwent isolated aortic valve repair, 9 (12.5%) underwent aortic and mitral valve repair, and 7 (9.7%) had other associated procedures. All patients underwent leaflet resection, including 35 (48%) at the raphe. The mean aortic occlusion time was 39 +/- 12 minutes. There were no operative deaths. The severity of aortic insufficiency, as assessed by Doppler echocardiography (graded from 0 to 4) preoperatively and intraoperatively and at late follow-up, was 3.6 +/- 0.6, 0.4 +/- 0.4, and 0.9 +/- 0.8, respectively, with a p value of < 0.0001 for the latter two values versus the preoperative one. There have been no postoperative deaths. Patients did not receive anticoagulation treatment and there were no strokes or episodes of endocarditis. Six patients have required reoperation; 3 underwent repeat repair. The Kaplan-Meier freedom from aortic valve reoperation probabilities at 12 and 24 months were 94% and 89.5%, respectively. We conclude that valvuloplasty for insufficient bicuspid aortic valves is technically safe, is associated with a low incidence of recurrent insufficiency, and has been associated with no other valve-related complications.

Actuarial Analysis↗
PubMed1994

Gastroepiploic and inferior epigastric arteries for coronary artery bypass. Early results and evolving applications.

BACKGROUND: Internal thoracic artery (ITA) conduits are known to provide long-term patency and increased patient survival with low morbidity after coronary artery bypass grafting (CABG). Excellent clinical results with the ITA have stimulated interest in additional arterial grafts. METHODS AND RESULTS: To review our experience and evaluate postoperative complications associated with these new conduits, from May 1985 to September 1993, we studied 290 patients who underwent CABG using additional arterial conduits. The right gastroepiploic artery (GEA) was used in 152 patients and the inferior epigastric artery (IEA) was used in 130 patients. Eight patients with both GEA and IEA grafts were excluded. Patient records were analyzed as to preoperative characteristics, angiographic findings, operative data, and postoperative complications. Statistical analysis was done using the Pearson chi 2 statistic and the t test. Ninety-eight percent of patients received one concomitant ITA graft, and the majority of patients in both groups had bilateral ITA grafts. The GEA group had a higher proportion of reoperations (GEA group, 54%; IEA group, 16%; P < .001), previous myocardial infarction (MI) (GEA group, 67%; IEA group, 50%; P = .004) and New York Heart Association class IV (GEA group, 28%; IEA group, 6%; P = .001). The IEA group was generally slightly older (IEA group, 56 years; GEA group, 52 years; P = .001). Hospital mortality (GEA group, 4%; IEA group, 0.8%) and postoperative morbidity (mediastinal bleeding, infection, stroke, MI, and low cardiac output) were not significantly different between the two groups or from our experience with routine CABG using the ITA. Three intraabdominal complications occurred in the GEA group: 2 episodes of bleeding and 1 of pancreatitis. One patient in the IEA group had abdominal wall bleeding. With overall short follow-up, angiographic patency in a small number of patients has been good: 80% for the GEA group and 85.7% for the IEA group. CONCLUSIONS: We conclude that the morbidity associated with these additional arterial conduits is low and is comparable with that associated with routine CABG using the ITA. Currently we use the ITA for primary targets and alternative arterial conduits for vessels of secondary importance or when the ITA and/or saphenous vein is not available.

Abdominal Muscles↗
PubMed1994

Surgical treatment of isolated left anterior descending coronary stenosis. Comparison of left internal mammary artery and venous autograft at 18 to 20 years of follow-up.

To assess the long-term results of the surgical treatment of isolated left anterior descending coronary artery stenosis and compare surgical strategies for graft selection, we reviewed 100 consecutive patients receiving left internal mammary artery-to-left anterior descending artery grafts and 100 consecutive patients who received a saphenous vein autograft to the left anterior descending artery. All patients underwent operation from 1971 through 1973. The internal mammary artery and saphenous vein graft groups were equivalent with regard to preoperative clinical and angiographic variables, except that patients receiving left internal mammary artery grafts had a higher prevalence of noncritical disease (less than 50% stenosis) in the circumflex and right coronary arteries than did the saphenous vein graft group. Mean follow-up for the internal mammary artery and saphenous vein graft groups was 18.7 years and 20.7 years, respectively. The 18-year outcome was superior for the internal mammary artery group. Cox regression analysis confirmed that patients with left internal mammary artery grafts had superior survival, intervention-free survival, and event-free survival (all p < 0.01). The presence of noncritical disease in other vessels adversely affected intervention-free survival and event-free survival for both groups (all p < 0.03) and decreased survival for the saphenous vein graft group (p = 0.01) but not for the internal mammary artery group (p = 0.24). We conclude that in long-term follow-up of surgically treated isolated left anterior descending artery stenosis (1) the left internal mammary artery consistently yields better overall and intervention-free survival than does the saphenous vein graft, (2) outcome is influenced by the presence of noncritical disease in other vessels at the initial operation, and (3) deployment of the left internal mammary artery in the treatment of isolated left anterior descending artery stenosis yielded 18 years of intervention-free survival of 60.5% and provides a standard for comparison with other forms of therapeutic intervention.

Coronary Angiography↗
PubMed1994

Influence of arterial coronary bypass grafts on the mortality in coronary reoperations.

From 1988 through 1991, 1663 patients underwent a first reoperation for isolated coronary bypass grafting with 62 (3.7%) in-hospital deaths. At the primary operation, 575 patients had received at least one internal thoracic artery graft and 489 patients had at least one patent internal thoracic artery graft present at the time of reoperation. At reoperation, 1014 patients received at least one internal thoracic artery graft, 10 received an inferior epigastric graft, and 37 received a gastroepiploic graft. Of 489 patients with patent internal thoracic artery grafts at reoperation, the internal thoracic artery was damaged in 17 (3.5%); of 428 patients with a patent internal thoracic artery graft to the left anterior descending coronary artery, 14 (3.3%) had graft damage necessitating regrafting. All patients with damaged internal thoracic arteries survived. Multivariate testing of variables for their association with in-hospital mortality identified no internal thoracic artery graft at either primary surgery or reoperation (p < 0.0001), a history of congestive heart failure (p < 0.0001), advancing age (p = 0.018), female gender (p = 0.029), and emergency operation (p = 0.01) as factors linked to increased risk. Left ventricular function, left main stenosis, extent of native coronary atherosclerosis, and the interval between operations did not influence mortality. Furthermore, the presence of an atherosclerotic vein graft to the left anterior descending coronary artery a factor shown to increase in-hospital risk in previous studies did not increase risk during these years. We attribute the observation that patent internal thoracic artery and atherosclerotic vein grafts do not appear to be factors specifically increasing the risk of reoperation to the use of retrograde cardioplegic solution and increased surgical experience. The use of internal thoracic artery grafts at a primary operation does not increase the risk of a reoperation, and the use of internal thoracic artery grafts at reoperation does not increase in-hospital morbidity or mortality.

Age Factors↗