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Biomedical subjects

G L Grunkemeier

Publications and source records attributed to G L Grunkemeier.

At least 91 records · Page 5Linked to original sources
PubMed1986

Ten year survival after coronary artery bypass surgery for angina in patients aged 65 years and older.

We have assessed the long-term results of coronary bypass surgery for angina from 1974 to 1983 in 1304 patients aged 65 years and older (group 1). Using actuarial techniques, we determined that the 5 year and 10 year survival rates for patients 65 years old or older were 81 +/- 2% and 65 +/- 3% (mean +/- SE), respectively. The patients aged 65 years and older were further subdivided into those aged 65 to 74 years (group 1a) and 75 to 84 years (group 1b) and were compared with 1700 patients aged 55 to 64 years (group 2). The operative mortality in the three subgroups was 3%, 3%, and 2%, respectively (p = NS). For coronary bypass surgery, the duration of hospital stay was significantly longer (p less than .0001) by a mean of 1 to 2 days for group 1 patients and the cost of hospitalization was higher by a mean of $ 700 (p = .25). The cost of hospitalization was significantly higher only for group 1b patients (p = .005). The 5 year survival rates for the three subgroups (1a, 1b, and 2) were 83 +/- 2%, 73 +/- 5%, and 91 +/- 1%, respectively, and the 10 year survival rates were 66 +/- 3%, 65 +/- 7% (7 year rate for subgroup 1b), and 77 +/- 2%, respectively. The lower survival rates for subgroups 1a and 1b were significant (p less than .001); however, this lower survival was only seen in men.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

Late ball variance with the Model 1000 Starr-Edwards aortic valve prosthesis. Risk analysis and strategy of operative management.

The first generation of aortic ball-valve prostheses, used until 1965, was associated with poppet damage owing to fatty infiltration of the silicone rubber ball, a phenomenon termed ball variance. For the Model 1000 Starr-Edwards valves, almost all cases were discovered before 8 years. However, a review of our patients still at risk with the original valve and poppet, prompted by other recent reports of late ball variance, has shown that severe variance can exist up to 20 years after implantation. There is a relationship between the year of valve implantation and the timing and severity of ball variance for the overall series of patients surviving operation, but for the subgroup currently at risk the sample sizes are too small to detect any difference, if one still exists. Only three of 12 patients in the current subset were found to have severe variance. Simple ball change has been the operation of choice. Prophylactic reoperation is not indicated in the current subset, but patients require careful follow-up and should be considered for reoperation should symptoms develop.

Adult↗
PubMed1986

Effect of initial reperfusion temperature on myocardial preservation.

The effect of initial postischemic reperfusion temperature on myocardial preservation was studied in the isolated working rat heart model. After baseline measurement of aortic flow rate, coronary flow rate, and heart rate, 40 hearts were subjected to 60 minutes of ischemic arrest at 15 degrees C induced with a single dose of cold potassium cardioplegic solution. Hearts were then revived with a 10 minute period of nonworking reperfusion at 28 degrees, 31 degrees, 34 degrees, or 37 degrees C (10 hearts each), followed by 5 minutes of nonworking reperfusion at normothermia, followed by 30 minutes of working perfusion. Repeat measurements of function were obtained and postischemic release of creatine kinase into coronary effluent was determined. Recovery of aortic flow was significantly reduced at lower initial reperfusion temperatures (75% at 28 degrees C versus 88% at 37 degrees C) and the effect was approximately linear throughout the range studied (p less than 0.05). Release of creatine kinase into coronary effluent was greater at lower initial reperfusion temperatures (421 ImU/min/gm wet weight at 28 degrees C versus 115 ImU/min/gm wet weight at 37 degrees C), also in a linear manner (p less than 0.05). In this model, initial postischemic hypothermic reperfusion is deleterious to cellular integrity and functional recovery of the preserved myocardium. Studies in higher animals and humans are warranted to further evaluate the effect of initial reperfusion temperature on myocardial preservation.

Animals↗
PubMed1985

Late results of combined mitral valve replacement and coronary bypass surgery.

The incremental risk of coronary bypass surgery was analyzed in 718 patients undergoing mitral valve replacement between 1971 and 1983. Ninety-eight patients (14%) had significant coronary artery disease requiring coronary bypass surgery. In 70 of these patients, the origin of the mitral valve disease was nonischemic, whereas 28 patients had ischemic mitral regurgitation unsuitable for conservative valve surgery. There were six operative deaths (9%) and four perioperative myocardial infarctions (6%) after mitral valve replacement and coronary bypass surgery for nonischemic mitral valve disease. Operative mortality was related to low output cardiac failure before operation or perioperative myocardial infarction. Actuarial curves predict survival (+/- standard error) of 55 +/- 7% at 5 years and 43 +/- 8% at 10 years. Preoperative functional class was the only significant predictor of long-term survival in this group (p less than 0.05). The actuarial survival of the 620 patients without coronary artery disease who underwent mitral valve replacement alone was 63 +/- 3% at 10 years. This was significantly better than that of the 70 patients who underwent mitral valve replacement and coronary bypass surgery for nonischemic mitral valve disease (p less than 0.001). Conversely, 5 year survival of the 28 patients with ischemic mitral regurgitation was 43 +/- 10%. This confirms the negative detrimental effect of an ischemic origin of mitral valve disease on survival after mitral valve replacement and coronary bypass surgery (p less than 0.0001).

Adult↗
PubMed1985

Mitral replacement: clinical experience with a ball-valve prosthesis. Twenty-five years later.

The purpose of this report is to review the results of mitral valve replacement since a first report in the Annals of Surgery in 1961, in order to determine the relative importance of new valve designs versus other surgical variables. The continued use of the silastic ball valve in its 1966 configuration (Model 6120), by providing a comparative data base for other new prosthetic valves, allows this analysis. For a valid comparison with the tilting disc (Bjork-Shiley) and the porcine (Hancock and Carpentier-Edwards) valves, only results with the silastic ball valves implanted during comparable time frames should be used. (Formula: see text) Thus, there are no significant differences in the results obtained with the silastic ball valve in time frames comparable to other contemporary valves introduced in the early 1970s. Improved results, therefore, must be non-prosthetic valve related.

Actuarial Analysis↗
PubMed1985

Coarctation of the aorta in patients younger than three months. A critique of the subclavian flap operation.

Unexpected and disappointing late results with the subclavian flap operation prompted this analysis of repair of coarctation in infants under 3 months of age. A total of 134 such patients underwent surgical repair since 1960 with 55 end-to-end anastomoses performed earlier in our experience (mean follow-up 5.0 years) and 67 subclavian flap angioplasty operations performed more recently (mean follow-up 2.0 years). The operative mortality was not significantly different (p = 0.3) between end-to-end anastomosis (29%) and subclavian flap angioplasty (19%), but it was significantly higher (p less than 0.01) in the first week of life (56%). Recurrent coarctation occurred in 16 cases, necessitating reoperation. The reoperation-free rates (with standard error) at 5 years for end-to-end anastomosis and subclavian flap angioplasty were 92% +/- 5% and 75% +/- 7%, respectively (p = 0.01). Eight of 10 patients who had reoperation after angioplasty had early recurrence with continued involution of the periductal tissues and growth of the posterior aortic ridge. Six patients who had recurrence after anastomosis demonstrated late anastomotic growth failure. The most common reoperation technique was patch aortoplasty (10 patients). The high incidence of early recurrence with subclavian flap angioplasty in infants under 3 months of age suggests end-to-end anastomosis as the procedure of choice when applicable.

Aorta, Thoracic↗
PubMed1985

Influence of age at operation on late results with subclavian flap aortoplasty.

Despite the popularity of subclavian flap aortoplasty for repair of aortic coarctation, reported experience and follow-up in neonates is surprisingly limited. This paucity of reports prompted this review of age-related late recurrence rates. Of 83 patients having subclavian flap aortoplasty from 1976 to 1983, 60 were less than 8 weeks of age at operation (mean 2.6 weeks). Operative and late mortality were 18% and 14%, respectively. After a mean follow-up of 26 months, 10 patients have experienced recurrent coarctation (a mean of 10 months elapsed between operations). For 23 patients older than 8 weeks of age at operation (mean 20 months), operative and late mortality were 13% and 10%, mean follow-up is 16 months, and no patient has yet experienced recurrence. Thus, 75% of infants less than 8 weeks of age at operation are free of recoarctation at 2 years, and 100% of older children are free of recoarctation at 2 years (p = 0.06). Review of the literature corroborates our findings. The difference in recurrence rates may be due to age-dependent involution of residual coarctation tissue unavoidably left in place during subclavian flap aortoplasty. We conclude that subclavian flap aortoplasty is effective for correction of coarctation in infants, but patients less than 8 weeks old have a significant risk of early recurrence. Based on this review and our recently reviewed experience with end-to-end anastomosis, our preference is to use the latter in this age group when technically feasible.

Age Factors↗
PubMed1985

Valvotomy for pulmonary atresia with intact ventricular septum. A disciplined approach to achieve a functioning right ventricle.

During the past 20 years, a consistent policy in applying early valvotomy has resulted in a unique opportunity to appraise the long-term results of this approach in pulmonary atresia with intact ventricular septum. Since 1964, 27 of 35 patients with pulmonary atresia with intact ventricular septum had type 1 or 2 right ventricle, 25 of these had early valvotomy, seven with and 18 without concomitant shunt. The remaining two patients with type 2 right ventricle and the eight patients with type 3 right ventricle received a shunt alone. Overall operative mortality was 34%; for those patients weighing more than 3 kg and those operated upon since 1977, it was 18% and 16%, respectively. There were 17 survivors of early valvotomy: 11 had valvotomy alone and six had valvotomy with shunt; 12 had type 1 right ventricle and five had type 2 right ventricle. Survival rates (+/- standard error) for these 17 patients were 85% +/- 10% and 68% +/- 17% at 5 and 10 years, respectively. The probability of reoperation was 100% by 6 years of age; outflow patch reconstruction was employed in all patients in whom reoperation has been performed. Aggressive follow-up and early recatheterization were essential features of management. Delayed reconstruction after shunt alone was unsuccessful in three patients. Primary valvotomy without shunt is the operation of choice for patients with pulmonary atresia with intact ventricular septum and type 1 right ventricle. Concomitant shunt may be required for some patients with type 1 and most with type 2 right ventricle, selected preoperatively by angiography or after valvotomy by clinical necessity. Delayed right ventricular reconstruction after shunt alone is not an acceptable approach when an outflow tract is present.

Cardiac Catheterization↗
PubMed1984

Thrombosis of mechanical cardiac valves: a qualitative comparison of the silastic ball valve and the tilting disc valve.

A review of 817 mitral and aortic Silastic ball valve implantations with a follow-up of 3,554 total patient-years yielded only seven cases of valve thrombosis. Time-related risk was 0.4% per patient-year in the mitral position and 0.1% per patient-year in the aortic position. Four of five mitral and one of two aortic ball valve thromboses were successfully managed by valve rereplacement . At least five of the seven patients presented with a prodrome (lasting at least 3 months) of symptoms of progressive heart failure and, occasionally, embolic episodes due to gradually increasing prosthetic stenosis by thrombus. This lengthy time course is in contrast to the more frequent rapid catastrophic thrombosis that occurs with the Björk-Shiley tilting disc valve. Recognition of the prodrome of Silastic ball valve thrombosis provides an opportunity for life-saving surgical intervention.

Adult↗
PubMed1984

Thrombotic and embolic complications with silastic ball prosthetic valves.

Eighteen years of continuous clinical use with the Starr-Edwards ball-valve prosthesis provides an extensive data base for comparison with more recently introduced cardiac prostheses, and establishes the credentials of this valve for current clinical use. Since 1965, 558 aortic (model 1260) and 285 mitral (model 6120) ball-valve prostheses have been inserted at the University of Oregon. Thromboembolic rates for the entire series (1965-1983) and our more recent experience (1973-1983) were 3.8% per year and 2.8% per year for the aortic valve; and 5.1% per year and 2.6% per year for the mitral valve. Patients who had experienced one embolic episode were substantially more likely to experience a subsequent event. Thrombotic stenosis was seen at rates of 0.1% per patient year and 0.4% per patient year for the aortic and mitral valves, respectively. These results are compared with other current series using a variety of mechanical and tissue prostheses. The Starr-Edwards valve remains a durable mechanical cardiac prosthesis with thromboembolic complications similar to most other current prostheses. Thrombotic stenosis tends to be rare, gradual, and electively managed as opposed to the sudden, unpredictable, and catastrophic thrombosis seen with tilting disc valves.

Actuarial Analysis↗
PubMed1984

Late surgical results for ischemic mitral regurgitation. Role of wall motion score and severity of regurgitation.

The indication for concomitant valve operations for ischemic mitral regurgitation is examined in 120 consecutive patients with regurgitation who had coronary bypass. Ischemic mitral regurgitation was mild in 56%, moderate in 18%, and severe in 27%. Compared with patients without mitral regurgitation who underwent coronary bypass, significantly more patients with regurgitation had cardiomegaly (31% versus 5%), left heart failure (42% versus 6%), and abnormal wall motion scores (71% versus 42%). Eighty-three patients (69%) with ischemic mitral regurgitation had coronary bypass alone and 37 (31%) also had a valve operation. All patients with mild ischemic mitral regurgitation were treated by coronary bypass alone, as compared to 67% with moderate and 6% with severe regurgitation. Operative mortalities for mild, moderate, and severe ischemic mitral regurgitation were 4%, 10%, and 38%, respectively; 5 year survival rates were 82%, 60%, and 48%, respectively. Other significant determinants of survival were wall motion score, shock, cardiomegaly, left heart failure, and acute and multiple myocardial infarctions. Patients with mild ischemic mitral regurgitation and a low wall motion score (n = 40) had a 5 year survival rate of 94%. For patients with either moderate/severe regurgitation (n = 27) or a high wall motion score (n = 25), but not both, the 5 year survival rate was 70%. In 20 patients with both a high wall motion score and moderate/severe regurgitation, it was 33%. An additive detrimental effect is apparent. The change from mild to moderate/severe ischemic mitral regurgitation was equivalent to an increase of about 8 wall motion score units in terms of effect on survival. Ischemic mitral regurgitation is a powerful additive risk factor to wall motion score in coronary bypass. Mild regurgitation is best managed by coronary bypass alone. If regurgitation is moderate, it may still be possible to avoid a valve operation and have acceptable results. Severe ischemic mitral regurgitation usually necessitates coronary bypass and a mitral valve operation.

Adult↗
PubMed1983

Coronary bypass operation following acute complicated myocardial infarction.

The indications for operation to correct acute mechanical defects after myocardial infarction are clearly established. Less clear is the use of surgical procedures for nonmechanical complications such as persistent ischemia or circulatory collapse. Between 1974 and 1981, 80 patients underwent coronary artery bypass grafting (CABG) within 2 weeks of infarction. Continued pain was the indication in 83% and cardiogenic shock in 17%. Seventeen patients were operated upon within 24 hours of infarction, 35 from 1 to 7 days, and 28 from 8 to 14 days. Eighty-one percent were men; mean age was 58 years. In 39% of patients the infarction was the premier symptom of coronary artery disease. Sixty-two percent had impaired left ventricular function as judged by left ventricular end-diastolic pressure greater than 15 mm Hg or abnormal wall motion seen on ventriculogram. Overall operative mortality was 5.0%; early mortality by indication was 3.0% for pain and 14.3% for shock. Operation for pain carried a 7.7% mortality if done within 48 hours of infarction and was 0% for those patients operated upon after that time. The status of 90% of all patients was known as of December, 1981, with a mean follow-up of 2.9 years. Life-table analysis demonstrates a 5 year survival rate of 85% +/- 6% in the group operated upon for pain. CABG in the immediate postinfarction period can be done safely with a 5 year survival in patients without hemodynamic compromise comparable to that of patients with chronic angina undergoing elective operation. These results should encourage the application of early postinfarction CABG in other high-risk subgroups of patients.

Angina Pectoris↗
PubMed1983

Aortic valve replacement with coronary bypass grafting. Significant determinants of ten-year survival.

Concomitant aortic valve replacement (AVR) and myocardial revascularization were performed on 197 patients between 1969 and 1981. Operative mortality during the period 1969 to 1975 was 15.6% compared to 5.0% for the years 1976 to 1981 (p less than 0.02). The incidence of perioperative myocardial infarction (PMI) declined over the same period from 14.2% to 2.0% (p less than .01). Functional class and left ventricular end-diastolic pressure significantly influenced mortality, whereas age, sex, duration of symptoms, cardiac index, wall motion abnormality, type of valve lesion, and completeness of revascularization did not. Type of myocardial preservation did not significantly affect operative mortality, although a trend favoring either cardioplegia or continuous perfusion of both coronary ostia and grafts was observed. Life-table analysis shows a survival rate during the 10 year follow-up period equal to that of patients undergoing isolated AVR. Cornary bypass grafting (CABG) returns patients with combined aortic valve (AVD) and coronary artery disease (CAD) to a prognostic curve determined by their valvular disease alone.

Adult↗
PubMed1982

Acute effects of alcohol in patients with congestive heart failure.

We evaluated the acute effects of moderate alcohol consumption in eight patients with New York Heart Association Functional Class III-IV congestive heart failure. Hemodynamic and echocardiographic variables were measured at baseline and then repeated at 30-minute intervals after ingestion of alcohol, 0.9 g/kg body weight, in the form of 80 proof vodka. Mean peak blood alcohol levels (+/- SE) at 60 minutes were 117 +/- 8 mg/dL. A significant reduction in mean arterial pressure, pulmonary artery and pulmonary artery wedge pressures, and systemic vascular resistance occurred over the first 90 minutes. Neither cardiac index, stroke volume index, stroke work index, nor echocardiographic variables were significantly changed. In patients with heart failure, a single moderate dose of alcohol reduces afterload by dilating arterial resistance vessels. No evidence of acute deterioration in cardiac performance was seen. In such patients occasional consumption of moderate dose alcohol can be safely tolerated.

Adult↗
PubMed1981

The ultimate prognosis after valve replacement: an assessment at twenty years.

Our experience over a 20-year period consists of 2,135 patients with initial caged-ball valve replacement: 52% aortic, 34% mitral, 12% double, and 2% triple-valve replacements, with 59.2, 39.8, 10.3, and 2.7 patient-centuries of follow-up, respectively. Fifteen-year actuarial survival (+/- standard error) was 43 +/- 2% for aortic and 44 +/- 3% for mitral valve replacement, and 27 +/- 5% for double-valve and 23 +/- 7% for triple-valve replacement. Restricting attention to patients operated on since 1973 divides the series almost in half and does not dramatically improve the 5-year actuarial survival (from 66 +/- 2% to 71 +/- 3% and from 70 +/- 2% to 78 +/- 3% for aortic valve replacement and mitral valve replacement, respectively). There was some alteration in the causes of late death: the largest percentage of deaths in both the earlier and current groups, 52%, was cardiac related whereas only 24% and 13%, respectively, were valve related. Over the past two decades operative mortality has declined and, to a lesser extent, late survival after mitral valve replacement has improved. The incidence of embolism has decreased significantly, most notably with the Silastic ball valves. Dramatic improvements in late results will occur primarily by modifying the cardiac-related death rate through earlier operation and improvements in the medical management of postoperative arrhythmias and congestive heart failure.

Actuarial Analysis↗
PubMed1981

Cardiac valve replacement in patients over 75 years of age.

Elderly patients with symptomatic cardiac valvular malfunction have a grave prognosis if managed medically but can be offered a reasonable chance for long-term survival and a good chance for improvement by replacement of the malfunctioning valve. A series of patients 75 years of age and older who underwent aortic valve replacement (31 patients) mitral valve replacement (9 patients), or combined valve replacement (on patient) has been reviewed. The overall operative mortality for aortic valve replacement was 23% (17% over the past 5 years) and the 5-year actuarial survival was 54 +/- 11%. The operative mortality for mitral replacement was 11% and the 5-year actuarial survival was 55 +/- 21%. The average hospital stay for survivors was 19 days after aortic valve replacement. Four patients have had embolic events since valve replacement, 3 after aortic and one after mitral valve replacement. The addition of coronary artery bypass surgery to the valve replacement procedure is becoming more frequent and may have contributed to improved operative survival. A literature review of reported clinical experience shows that the advancement of cardiac surgery has permitted a redefining of the group thought as "elderly", and that this group has an improved operative survival with the improvements in cardiac valve surgery.

Age Factors↗
PubMed1980

The use of time-interrelated covariates to predict survival following aortic valve replacement.

One hundred four patients survived isolated aortic valve replacement with the model 1200 prosthesis between 1965 and 1968, with a 12-year survival of 64%. Multiple regression survival analysis was employed in an attempt to determine which of 26 preoperative variables affected late survival and to devise a formula to predict survival for a given individual. The most important variables in the regression equation were right atrial mean pressure, etiology, and sex. The effect of the last two were found to vary with time over the 12-year post-operative period. An extension of the standard regression analysis technique was developed to incorporate time-related cofactors into the model. Based on the multiple regression model, 12-year survival was estimated to range from 92% to 14% for the best and worst combinations, respectively, of the three significant variables. The advantages of the regression method are outlined and the findings of other studies with regard to factors affecting survival after aortic valve replacement are summarized and discussed.

Adult↗