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Biomedical subjects

D G Pennington

Publications and source records attributed to D G Pennington.

At least 145 records · Page 8Linked to original sources
PubMed1981

Glenn shunt: long-term results and current role in congenital heart operations.

Fifty cyanotic patients (aged 2 days to 22 years) underwent Glenn shunts for tricuspid atresia and other cyanotic heart defects. Thirteen of 15 operative deaths occurred in infants less than 4 months old, and only 1 death has occurred in the last 9 years. Results were poor in patients with Ebstein's anomaly, truncus arteriosus, transposition of the great vessels, and complex defects other than tricuspid atresia and univentricular heart. Of the 35 patients followed from 0.9 to 14.8 years, 12 were followed for more than 10 years. None of the 11 late deaths could be attributed to complications of the shunt. Minimal evidence of intrapulmonary shunting was found by angiography, pulmonary venous oximetry, or radioisotopic studies. Late deterioration due to venous collaterals and decreased flow to the opposite lung necessitated Blalock-Taussig shunts in 6 and Fontan procedures in 10. All survived the Fontan procedures with minimal morbidity. These data support the concept that Glenn shunts do not necessarily result in pulmonary abnormalities and may be indicated as a staged procedure in a few selected patients prior to a Fontan procedure.

Adolescent↗
PubMed1981

Left main equivalent: results of medical and surgical therapy.

Stenosis of at least 50% of both the left anterior descending and circumflex coronary arteries proximal to their major branches has sometimes been called left main equivalent (LME) disease. During a 4-year interval, 189 LME patients were identified as surgical candidates by angiographic criteria. Coronary artery bypass grafting (CABG) was performed in 119 patients; 70 patients were managed nonoperatively. Treatment assignment was nonrandom. During the same interval, 203 patients with significant left main coronary artery (LMCA) stenosis and 742 patients with three-vessel disease without LMCA or LME stenosis underwent CABG. Follow-up is 99.2% complete at an average of 48 months (range 24--73 months). Operative mortality was significantly higher among LMCA patients (4.0%) than among LME surgical patients (0.8%) (p less than 0.05). Cumulative 5-year survival was better among LME surgical patients (98.2 +/- 1.3%) than among LME medical patients (75.9 +/- 5.7%) (p less than 0.0001) or LMCA surgical patients (92.8 +/- 2.1%) (p less than 0.03). All operative patient groups had a significantly lower incidence of myocardial infarction (10.3--13.4%) than the LME medical patients (25.7%) (p less than 0.05). Relief of angina was also significantly better in the operative groups (61--67.6%) than in LME medical patients (36%) (p less than 0.005). Major differences exist between LME and LMCA patients; LME is more properly considered a variant of multivessel coronary artery disease. Results of medical and surgical therapy suggest that patients with LME disease should be strongly considered for early operative therapy.

Aged↗
PubMed1980

The rectus abdominis myocutaneous free flap.

The successful transfer of a free rectus abdominis myocutaneous flap based on the inferior epigastric vessels is reported. The preliminary experimental investigations leading to the design of this flap are described.

Abdominal Muscles↗
PubMed1980

Clinical experience with cold blood as the vehicle for hypothermic potassium cardioplegia.

Intermittent cold ischemic arrest was compared with hypothermic potassium cardioplegia using cold blood as the vehicle in two consecutive series of patients having isolated coronary bypass grafting. Between January 1, 1977, and June 30, 1977, 196 patients were operated on using cold ischemic arrest. The incidence of perioperative infarction was 14.3%, and mean total myocardial ischemia time was 42 +/- 1.2 minutes. From July 1, 1977, to June 30, 1978, there were 428 operations done using cold blood with potassium. The incidence of perioperative infarction was 5.6% (p less than 0.005), and the mean total myocardial ischemic time was 80 +/- 2.1 minutes. In the five years prior to this study, the incidence of perioperative infarction was constant at 13% while operative mortality was declining from 5 to 1% and the need for postoperative myocardial support was declining also. Use of cold blood potassium cardioplegia compared with cold ischemic arrest for myocardial protection during coronary artery operations has significantly reduced the incidence of perioperative infarction while doubling cross-clamp time.

Aspartate Aminotransferases↗
PubMed1980

The rationale for operative therapy of symptomatic single-vessel coronary artery disease.

During an 8 year interval, 184 patients with symptomatic single-vessel disease underwent coronary artery bypass grafting (CABG). There were no operative deaths and only one late cardiac death (5 year cumulative survival 97.9%). At 48 months mean follow-up, 91% are angina free or improved. The low incidence of perioperative and late myocardial infarction (MI) and the preservation of ventricular function seen on follow-up catheterization suggest that coronary bypass operations yield significant benefits in severely symptomatic patients with single-vessel disease. Evidence is presented which supports the idea that single-vessel coronary artery disease may be a unique manifestation of coronary atherosclerosis and not one stage in a continuum.

Angiocardiography↗
PubMed1980

Bypass grafts to the left anterior descending coronary artery: saphenous vein versus internal mammary artery.

During the interval 1972 to 1977, of 1,522 patients undergoing isolated coronary artery bypass grafting (CABG), 1,459 received grafts to the left anterior descending coronary artery (LAD). Internal mammary artery (IMA) was used in 765 patients and reversed saphenous vein graft (SVG) in 694 patients. Choice of bypass graft was nonrandom. Clinical follow-up is available in 98% of patients. Angiography has been obtained in 69% of eligible patients at 1 month, 65% at 1 year, 62% at 3 years, and 63% at 5 years. There was no difference in operative mortality rates (IMA 1.4%, SVG 1.9%) or 5 year actuarial survival rates (IMA 87.6%, SVG 88.7%). Graft flows were consistently higher at operation with the SVG, but patency rates at each interval were significantly higher with the IMA. Perioperative and late myocardial infarction occurred significantly less often in IMA patients. Superiority in IMA graft patency became apparent after an initial "learning curve" of 2 years of experience. Maintenance and/or restoration of normal left ventricular function was more common in IMA patients operated upon after the initial 2 year experience. IMA grafts are recommended for LAD bypass when the LAD is 2.0 mm in diameter or less. Early results with sequential SVG to the LAD suggest that this may be a realistic alternative to the IMA and may approach the 1 year IMA graft patency rate of 92.6%.

Angina Pectoris↗
PubMed1979

Long-term results of myocardial revascularization.

During 1970 to 1977, among 1,733 patients who underwent isolated coronary bypass grafting, the operative mortality was 2.5 percent. Actuarial 5 year survival is 88.1 percent. At an average follow-up of 46 months (range 13 to 108), 90 percent of patients remain angina-free or with symptomatic improvement. The 5 year survival rate of patients with single vessel coronary artery disease is 97.9 percent. In patients with multivessel disease, operative survival appears to be favorably influenced by the presence of normal preoperative ventricular function. Late survival is significantly better in patients with multivessel disease with normal preoperative ventricular function or with complete revascularization. Risk of perioperative myocardial infarction has been appreciably reduced by the introduction of cold potassium chloride cardioplegia. Late myocardial infarction has occurred at an average annual risk of 1.46 percent. These data show that long-term survival and a small incidence of late myocardial infarction after myocardial revascularization are more likely in patients who undergo complete revascularization before significant left ventricular myocardial damage has occurred.

Adult↗
PubMed1979

Cold blood as the vehicle for potassium cardioplegia.

Cold blood with potassium, 34 mEq/L, was compared with cold blood and with a cardioplegic solution. Three groups of 6 dogs had 2 hours of aortic cross-clamp while on total bypass at 28 degrees C with the left ventricle vented. An initial 5-minute coronary perfusion was followed by 2 minutes of perfusion every 15 minutes for the cardioplegic solution (8 degrees C) and every 30 minutes for 3 minutes with cold blood or cold blood with potassium (8 degrees C). Hearts receiving cold blood or cold blood with potassium had topical cardiac hypothermia with crushed ice. Peak systolic pressure, rate of rise of left ventricular pressure, maximum velocity of the contractile element, pressure volume curves, coronary flow, coronary flow distribution, and myocardial uptake of oxygen, lactate, and pyruvate were measured prior to ischemia and 30 minutes after restoration of coronary flow. Myocardial creatine phosphate (CP), adenosine triphosphate (ATP), and adenosine diphosphate (ADP) were determined at the end of ischemia and after recovery. Changes in coronary flow, coronary flow distribution, and myocardial uptake of oxygen and pyruvate were not significant. Peak systolic pressure and lactate uptake declined significantly for hearts perfused with cold blood but not those with cold blood with potassium. ATP and ADP were lowest in hearts perfused with cardioplegic solution, and CP and ATP did not return to control in any group. Heart water increased with the use of cold blood and cardioplegic solution. Myocardial protection with cold blood with potassium and topical hypothermia has some advantages over cold blood and cardioplegic solution.

Adenosine Diphosphate↗
PubMed1979

The locking loop tendon suture.

The locking loop tendon suture is suggested as an effective method for suturing tendons where tension is likely during the early post-operative period. The relationship of the intratendinous parts of the suture to each other is critical to the resultant tensile strength. Experimental work has confirmed its strength and its lack of interference with the intrinsic vasculature of the tendons. Our results from this clinical repair of 72 tendons by this method have been better, in general, than we obtained with other currently popular methods.

Adult↗