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Biomedical subjects

O W Isom

Publications and source records attributed to O W Isom.

At least 109 records · Page 6Linked to original sources

Operative management of tricuspid regurgitation.

From January 1968 to June 1975 tricuspid regurgitation was encountered in 238 patients of a total of 1074 patients undergoing operations on the mitral valve. During this time tricuspid annuloplasty (TA) was performed in 137 patients and the tricuspid valve was replaced (TVR) in 101 patients. Comparison of hospital mortality of 15% (20 of 137) for TA as against 40% (40 or 101) for TVR suggests the superiority of repair over replacement. A new technique for repair makes this operation even more attractive. It satisfies the dual objectives of producing competency but not obstruction by creating a measured orifice. As experience with TA was gained, the incidence of valve replacement dropped from 69% (22 of 32) in the first 2 years of the study to 16% (11 of 70) for the last 2 years.

Adult↗

Long-term survival following coronary bypass surgery in patients with significant impairment of left ventricular function.

To assess the influence of coronary revascularization on the long-term survival of patients with debilitating angina and significant impairment of left ventricular function, analysis was done of 62 consecutive patients with severe angina and hypokinetic left ventricles (LVED larger than or equal to 20) undergoing coronary bypass at N.Y.U. Medical Center between January, 1971 and May 1974. Follow-up was 98% complete, range 4 to 41 months with a mean of 23 months. Multiple bypasses were done in 94% of the group; a left-ventricular scar was excised in 16%. There were six operative deaths (mortality 9.7%) and three late deaths, all within eight months after operation. Angina was either absent or substantially improved in 90% of surviving patients. Life-table analysis shows a two-year survival of 85%, very similar to the survival rate for patients with good ventricular function. Hence, with current techniques impaired ventricular function is not a major contraindication to bypass grafting.

Adult↗

The long-term influence of coronary bypass grafts on myocardial infarction and survival.

Approximately 1,000 coronary bypass procedures were performed at New York University between February 1968 and December 1973. This report reviews all elective operations performed for angina between 1968 and 1972, a total of 448 patients. In this five-year period the percentage of diseased arteries bypassed rose from 40% to 84%, and operative mortality decreased from 28% to less than 3%. There were a total of 28 operative deaths, mostly from myocardial infarction and low cardiac output. Operability was nearly 95%. The only fixed contraindication was chronic congestive failure. Over one-half of the patients had an abnormal ventriculogram, and there was some history of mild congestive failure in nearly 20%. Elevation of left ventricular end-diastolic pressure above 20 mm before operation was associated with a higher operative mortality, but the late mortality was similar to those with a normal preoperative end-diastolic pressure. In 383 surviving patients, angina was eliminated or greatly improved in 86%, unimproved in 12% and worse in 2%. Late angiograms were performed on 201 patients, studying a total of 445 venous grafts with an overall patency rate of 71%. Graft occlusion was sporadic and unpredictable, but over 90% of patients with multiple grafts remained with at least one patent graft. A late myocardial infarction occurred in 32 out of 420 patients surviving operation, and was fatal in eight. The cumulative incidence over a period of five years was 17%. Twenty-three deaths occurred following discharge from the hospital. Life-table analyses showed a five-year survival of 77% when all deaths were included, and a five-year cardiac survival of 81% when non-cardiac deaths were withdrawn alive at the time of death. The expected survival in a comparable population group without coronary disease was 92%, while data published by Sones of patients treated without operation showed a five-year cardiac survival of 66%. Current operative techniques have an operative mortality of 2-3% and a subclinical infarction rate of 5-10%. The ideal graft is yet evolving, but data with internal mammary artery grafts are most encouraging. A future goal should be a five-year graft patency of at least 80%. Because many infarcts probably develop from a relatively small decrease in coronary blood flow, either during rest or mild activity, the likelihood that future data will demonstrate a marked increase in longevity with bypass grafting is great.

Adult↗

Use of saphenous vein allografts for aortopulmonary artery anastomoses in neonates with complex cyanotic congenital heart disease.

A saphenous vein allograft was used to create an aortopulmonary communication in 16 infants with cyanotic congenital heart disease and ductus-dependent pulmonary blood flow. These grafts measured from 3 to 8 mm in diameter and were placed between the aorta and main pulmonary artery in eight patients, between aorta and right pulmonary artery in eight, and between aorta and left pulmonary artery in one (one child had two grafts). Before heparin was used, early in the series, four of these grafts occluded and three of the four infants died during attempted revision. Another infant died early from renal failure. Late mortality has claimed four: one from cerebral hemorrhage, two from hypoxia, and one at open-heart surgery for repair. There are eight late survivors (50%). Most of the allografts were used before small diameter Gore-Tex was available; in more recent patients, 4- to 6-mm Gore-Tex grafts have been used. In our most recent patient, however, the attempt to place a Gore-Tex graft was unsuccessful, but the more pliable saphenous vein graft was readily placed and an adequate shunt obtained. Both the saphenous vein graft and the Gore-Tex have the advantage of providing pulmonary flow without the higher risk of congestive failure or pulmonary hypertension seen in patients with a Waterston or Potts anastomosis. They are easier to perform, require less anesthesia time than the Blalock-Taussig shunt, last as long as the Blalock-Taussig when done under similar conditions, and are easy to take down at the time of total repair.

Aorta↗

Predictors and outcomes of cardiac complications following elective coronary bypass grafting.

Our objective was to determine the predictors of cardiac complications among a cohort of elective coronary artery bypass graft (CABG) surgery patients and to determine the relationship of such complications to subsequent quality of life and symptoms. A total of 248 patients were enrolled and 237 completed 6 month follow-up. The combined rate of both major and minor cardiac complications was 9.7% (n = 24). Patients in this study were evaluated preoperatively, monitored intraoperatively, followed immediately postoperatively and at 6 months. Major cardiac complications accounted for 3.6% (n = 9) and minor complications for 6% (n = 15). Using multivariable logistic regression analysis, the predictors of major cardiac complications were receiving diuretics preoperatively (p = .01) and increased time during cross-clamping (p = .006). At 6 months after surgery, 19% of the patients with postoperative cardiac complications experienced worsening of symptoms, in contrast to only 8% of those without cardiac complications (p = .03). We concluded that patients who were on preoperative diuretics and those who had longer cross-clamp times were at higher risk of cardiac complications. The majority of patients who had acute cardiac complications had improved function and symptoms at 6 months postoperatively.

Aged↗