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.

Year of operation as a risk factor in the late results of valve replacement.

The actuarial thromboembolic rates of aortic and mitral silicone ball valves used during the second decade of cardiac valve replacement are significantly lower than the rates for the same prostheses implanted during the first decade, as shown in the following table: (Formula: see text). The embolus-free rates are significantly different (p < 0.01) in both the mitral and aortic series. Five-year embolus-free rates for the composite-strut caged-ball, Björk-Shiley tilting disc, and porcine xenograft valves all fall in the range of from 81% to 92% for the mitral position and from 91% to 97% for the aortic. Thus the standard silicone ball-valve prosthesis, used during the current era, has a thromboembolic risk as low as that reported with other concurrently utilized valve substitutes. This striking reduction in thrombogenicity demonstrates that the time frame of implantation must be considered when evaluating the results of cardiac valve replacement.

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.

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.

Pheochromocytoma.

Twenty surgical and two autopsy cases of pheochromocytoma are reviewed. Preoperative diagnoses were reliably determined by urinary catecholamine excretion studies in most cases. Arteriography and computed axial tomography were the most consistently useful studies in localization of tumor. Preoperative alpha blockagde with phenoxybenzamine, although incomplete in most cases as judged by intraoperative hypertension or postexcision hypotension, appear to have been beneficial as there was not operative mortality. Continued hypertension after tumor removal can be expected in 25 percent of patients despite normalization of catecholamine excretion studies. The cause of this is unknown, but vigilance for recurrent tumor should be maintained.

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.

Changes in coronary bypass surgery leading to improved survival.

Coronary bypass surgery was performed on 439 patients between the years 1969 and 1973 (group A) and on 1,760 patients between the years 1974 and 1979 (group B). The operative mortality for group A was 3.9%; for group B, 1.3%; four-year survival for group A patients was 88.9% +/- 1.5% (mean +/- SE); for group B patients, 92.5% +/- 0.9%. The difference between the relative four-year survival rates (based on age- and sex-matched Oregon population) between group B and A was 6.2%; the lower operative mortality would account for only 2.6%. We conclude that the results of coronary bypass surgery have improved because of (1) a lower operative mortality, and (2) other factors that cannot be precisely defined at the present time but probably are the long-term result of better and more complete operative and perioperative techniques.