Biomedical subjects
Publications and source records attributed to R O Russell.
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Since the advent of endoscopic retrograde cholangiopancreatography (ERCP) in 1970 and endoscopic sphincterotomy (EST) in 1974, there has been rapid proliferation of endoscopic techniques for the diagnosis and therapy of benign and malignant biliary and pancreatic disorders. The ability to biopsy under direct vision, reliably obtain a pancreatogram, exclude other upper gastrointestinal disorders, and reexamine with ease, combined with the lack of hepatic puncture, has given the endoscopic route an undeniable advantage over the percutaneous transhepatic route for these interventions. Although some have become routine procedures (EST for postcholecystectomy choledocholithiasis; transpapillary stent insertion for inoperable biliary stenoses), the exact place of many of these interventions remains unclear, and the subject of prospective controlled studies where possible. This review attempts to give an overview of present and developing ERCP- and EST-based diagnostic and interventive techniques and their application to the wide spectrum of pancreatobiliary diseases.
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The metabolic and mechanical effects of a solution of glucose-insulin-potassium (G-I-K) were investigated in 18 patients who underwent diagnostic cardiac catheterization for coronary artery disease. All patients were paced at a rate of approximately 140 beats/min before and after infusion of G-I-K. Basal and paced left ventricular (LV) end-diastolic pressure, dP/dt, arterial substrate levels and osmolarity were measured in all 18 patients. In 13 patients cardiac index was also measured. In 5 patients arterial-coronary sinus measurements of oxygen, carbon dioxide, glucose, free fatty acids, lactate, alanine, glutamate, glutamine, ammonia and urea were made, in addition to coronary sinus blood flow. G-I-K increased the blood sugar level to approximately 200 mg/dl and raised the serum osmolarity 9 mosmol. Pacing alone raised the cardiac index 4% and pacing with G-I-K increased the cardiac index 6% (p less than 0.05). Pacing before G-I-K augmented dP/dt (21%) and pacing with G-I-K increased it (30%) (p less than 0.01). The metabolic changes noted included a shift in the respiratory quotient from 0.77 to 0.96 with G-I-K infusion (p less than 0.05). During G-I-K infusion the myocardial oxygen consumption at rest increased from 17.1 to 21.8 ml/min (23%, p less than 0.05). Myocardial oxygen consumption during pacing was similar before and after G-I-K infusion. Before G-I-K infusion nitrogen balance was slightly positive; after G-I-K infusion it was negative with regard to the nitrogen-containing compounds measured.(ABSTRACT TRUNCATED AT 250 WORDS)
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The Coronary Artery Surgery Study, CASS, enrolled 24,959 patients between August 1975 and June 1979 who were studied angiographically for suspected coronary artery disease. This paper compares the prognostic value for survival without early elective surgery of eight different indices of the extent of coronary artery disease: the number of diseased vessels, two indices using the number of proximal arterial segments diseased, two empirically generated indices from the CASS data, and the published indices of Friesinger, Gensini, and the National Heart and Chest Hospital, London. All had considerable prognostic information. Typically 80% of the prognostic information in one index was also contained in another. Our analysis shows that good prediction from angiographic data results from a combination of left ventricular function and arteriographic extent of disease. Prognosis may reasonably be obtained from three simple indices: the number of vessels diseased, the number of proximal arterial segments diseased, and a left ventricular wall motion score. These three indices account for an estimated 84% of the prognostic information available. 6-yr survival varies between 93 and 16% depending upon the values of these three indices.
To compare the relative merits of conventional and axial RAO/LAO angiography, we performed biplane left ventricular (LV) cineangiograms in 36 patients in both the conventional 30-degree RAO/60-degree LAO projection and in the axial 45-degree RAO/60-degree LAO/25-degree cranial projection, in random sequence. LV volumes were calculated by a computerized system utilizing modification of the area-length method. Eng-diastolic volume, end-systolic volume, and ejection fraction correlated closely between the two projections (r = 0.93, 0.95, and 0.86, respectively). The axial 60-degree LAO view projected the LV apex inferiorly, the LV outflow tract superiorly, reduced LV foreshortening, and "uncovered" the LV outflow tract in all cases. Segmental wall motion abnormalities of the ventricular septum, apex, and posterior wall were better evaluated by the axial 60-degree LAO view in patients with regional asynergy in these zones. The 45-degree RAO, compared to the 30-degree RAO view, allowed a true tangential view of the mitral valve and provided a large "clear area" between the mitral valve and descending aorta, which improved the ability to quantify mitral regurgitation. Thus, axial oblique LV angiography improves evaluation of LV regional wall motion and mitral valve function without compromising LV volume quantitation.
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With a few exceptions, prevailing data on return to work after coronary artery bypass surgery indicate no net gain in employment status for at least several years after the operation. Despite the improved surgical experience and advances in the medical management of postoperative patients, only limited employment benefits occur after surgery, and no gains in work rehabilitation over the past decade have been noted. Several characteristics--preoperative work status, nonwork income, occupation, relief of symptoms, age, perception of health, education and severity of disease--appear to be important for estimating the likelihood of employment after surgery. Other influences, such as attitudes of the family, employers and physicians, undoubtedly alter the probability of return to the work force, but are less well documented. Unless constructive approaches toward work rehabilitation are made, the possibility of return to gainful employment should not be considered an indication for or a necessary consequence of coronary artery bypass surgery.
Several prospective randomized studies of medical or surgical therapy have not shown that either form of management alone is uniformly superior with respect to mortality for unstable angina pectoris. Patients managed medically have a greater incidence of angina pectoris. Earlier studies indicated a higher rate of nonfatal myocardial infarction with urgent surgery. Present management includes hospitalization and early intensive medical therapy with nitrates and, usually, beta-blocking agents. Coronary arteriography is advised within a few days. If the patient has left main coronary artery disease or three-vessel disease, early coronary artery bypass graft surgery within days to a couple of weeks is advised. Otherwise, medical management is advised and elective surgery can be performed if the patient remains symptomatic.
The objective of this study was to evaluate the impact on survival of the anatomic extent of obstructive coronary artery disease and of two measures of left ventricular (LV) performance. This study is based on 20,088 patients without previous coronary artery bypass graft surgery who were enrolled in the registry of the National Heart, Lung, and Blood Institute Coronary Artery Surgery Study from 1975 to 1979. The cumulative 4-year survival of medically managed patients was analyzed to determine the survival of specific subsets of patients with obstructive coronary disease. The vital status of 99.8% of the patients was known. The 4-year survival of medically treated patients with no significant obstructive disease was 97%, in contrast to 92%, 84% and 68% in patients with one-, two- and three-vessel disease, respectively. The presence of left main coronary artery disease decreased survival significantly. The 4-year survival decreased from 70% to 60% in patients with three-vessel disease when significant obstruction of the left main coronary artery was also present. Patients with significant coronary artery disease who had an ejection fraction of 50--100%, 35--49%, and 0--34% had a 4-year survival of 92%, 83% and 58%, respectively. The systolic contraction pattern was assessed in five selected segments and given a score of 1--6, with a score of 1 for normal function, increasing to 6 if an aneurysm was present. In a patient with normal LV contraction in all five segments of the LV ventricular angiogram, the LV score would equal 5. Patients with an LV score of 5--11, 12--16 and 17--30 had 4-year survivals of 90%, 71% and 53%, respectively. Patients with good LV function (a score of 5--11) had a 4-year survival of 94%, 91% and 79% for one-, two- and three-vessel disease, respectively. Patients with poor left ventricular function (score of 17--30) had a 4-year survival rate of 67%, 61% and 42% in one-, two- and three-vessel disease, respectively. Thus, LV function is a more important predictor of survival than the number of diseased vessels.