Biomedical subjects
T J Ryan
Publications and source records attributed to T J Ryan.
Ankle bypass: should we go the distance?
This report reviewed the results of 47 distal arterial reconstructions to or below the level of the malleolus. The operations were performed by the techniques of popliteal-to-distal bypass (20 procedures) and in situ bypass (27 procedures). Seventy-five percent of patients had gangrene of ischemic ulceration, and all procedures were performed for limb salvage. Seventy-three percent of all patients were diabetic. The patency rates for popliteal-to-distal bypass with reversed saphenous vein were 92 percent at 24 months and 57 percent at 60 months, with a limb salvage rate of 70 percent at 60 months; the patency rates for popliteal-to-distal bypass with PTFE were 53 percent at 12 months and 0 at 36 months, with a limb salvage rate of 53 percent at 36 months; and the patency rate for in situ saphenous vein bypass was 96 percent at 24 months, with a limb salvage rate of 80 percent at 24 months. Early results are promising for ankle bypass using the techniques of popliteal-to-distal and in situ bypass.
Persistent left superior vena cava and right superior vena cava drainage into the left atrium without arterial hypoxemia.
A 46 year old patient who presented with an acute myocardial infarction was discovered to have a systemic venous communication with the left heart during attempted insertion of a pulmonary flotation catheter. There was no evidence of cyanosis or systemic arterial desaturation. A right superior vena cava that emptied into the right superior pulmonary vein and a persistent left superior vena cava draining into the coronary sinus were confirmed pathologically after death related to a brain abscess. The embryology, physiology and noninvasive diagnostic approach to this unique venous anomaly are discussed.
Cardiovascular abnormalities in the athlete: recommendations regarding eligibility for competition. Task force V: Ischemic heart disease.
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Acute and long-term effects of enalapril on the cardiovascular response to exercise and exercise tolerance in patients with congestive heart failure.
Enalapril is a recently developed angiotensin-converting enzyme inhibitor that improves cardiac function at rest in patients with congestive heart failure. This study investigated the acute effects of enalapril on the cardiovascular response to exercise, and then evaluated the long-term effects of enalapril on exercise capacity and functional status during a 12 week placebo-controlled trial in patients with heart failure. Ten patients underwent hemodynamic monitoring while at rest and during incremental bicycle exercise before and after 5 to 10 mg of enalapril orally. At rest, enalapril decreased mean blood pressure 13% (p less than 0.01) and systemic vascular resistance 20% (p less than 0.05) and increased stroke volume index 21% (p less than 0.01). During maximal exercise, enalapril decreased systemic vascular resistance and increased both cardiac and stroke volume indexes. Enalapril acutely increased exercise duration (p less than 0.05) and maximal oxygen consumption (p less than 0.001). These 10 patients and an additional 13 patients were then randomized to either placebo or enalapril treatment and followed up for 12 weeks. Of the 11 patients assigned to active treatment, 73% considered themselves improved compared with 25% of the patients assigned to placebo treatment (p less than 0.02). During long-term treatment, exercise capacity increased in patients receiving enalapril (p less than 0.001) but was unchanged in patients receiving placebo (intergroup difference, p less than 0.05). During long-term treatment, no adverse effects of enalapril occurred. Thus, enalapril improves cardiac function at rest and during exercise. Compared with placebo, maintenance therapy with enalapril results in symptomatic improvement and increased exercise capacity.
Experimental angioplasty: circumferential distribution of laser thermal energy with a laser probe.
A new laser probe that converts argon laser energy to heat in a metallic cap on a fiberoptic fiber was compared with a bare argon laser fiberoptic catheter system for the dissolution of atherosclerotic obstructions under fluoroscopic guidance in 24 atherosclerotic rabbits. Twelve animals were randomly assigned to receive treatment with either a bare fiberoptic system or a laser probe coupled to an argon laser. Both fibers had similar outer (0.9 mm) and core (400 mu) diameters. Pulses of 1 watt for 1 second's duration were delivered from the tip of the fiberoptic system, while pulses of 6 watts for 2 seconds' duration were delivered to the laser probe. The results of angiography indicated that widening of luminal stenosis was seen in only 2 of 12 animals treated with the fiberoptic system compared with 8 of 12 animals treated with the laser probe. Perforation of the vessel wall occurred more frequently with the fiberoptic fiber (9 of 12 animals) as compared with the laser probe (1 of 12 animals). Histologic examination of direct laser radiation with the fiberoptic fiber revealed a small localized laser defect along one side of the vessel wall associated with charring, a gradient of thermal injury and considerable thrombus formation. In contrast, those vessels treated with the laser probe showed histologic evidence of thermal injury distributed evenly around the entire luminal circumference. This was associated with minimal charring, a gradient of thermal injury and thinner, flatter thrombus formation. Carbonization of the metallic tip and adherence of atherosclerotic debris with secondary vessel tearing were potential adverse effects of the laser probe.(ABSTRACT TRUNCATED AT 250 WORDS)
Acute palmoplantar pustulosis.
This paper describes five cases of an uncommon acral rash, acute palmoplantar pustulosis, which is precipitated by infection, and may represent a true pustular bacteria. Acute and chronic palmoplantar pustulosis are probably different forms of the same disease, but the prognosis in the acute form is good and aggressive therapy is not indicated. The relationship to psoriasis is discussed.
Tattoo removal using infra-red coagulation.
Using a radiation source from which the output is maximal in the near infra-red range, we have successfully treated thirty-six tattoos in twenty-one patients. This technique is described and its place in practice is discussed.
Dermatitis repens, Lapière and generalized pustular psoriasis.
The presence of subcorneal pustules in a solitary, indolent, crusted plaque, or in erythema annulare-like lesions with a trailing scale, is evidence of atypical psoriasis. When these lesions appear late in life there is a significant risk of generalized pustular psoriasis with a poor prognosis. A case is presented in whom both of these atypical forms occurred and who developed severe generalized disease. Clinical and histological features are described.
Unilateral dermatomal superficial telangiectasia.
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Cicatricial pemphigoid with nail dystrophy.
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Morphosis, occult forces and ectoplasm--the role of glues and proteolysis in skin disease.
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Haemodynamic and neurohumoral response to exercise in patients with congestive heart failure treated with captopril.
The contribution of the renin-angiotensin system to the cardiovascular response to exercise was studied in 12 patients with congestive heart failure. The haemodynamic effects of captopril were measured at rest and during supine bicycle exercise. After captopril administration, resting systemic vascular resistance fell by 26.6% and mean blood pressure by 16.7% and cardiac index increased by 19.7%. During exercise, captopril decreased systemic vascular resistance by 25.6% and mean blood pressure by 8.2% and increased cardiac index by 24.4%. Pulmonary wedge pressure fell by 25% at rest but was not altered by captopril during exercise. Pretreatment plasma renin activity increased from 13.4(16.0) ng/ml/hr (10.3(12.3) mmol/l/hr) at rest to 20.0(27.8) ng/ml/hr (15.4(21.4) mmol/l/hr) during exercise. Pretreatment plasma noradrenaline concentration increased from 659(433) pg/ml (39(25.6) nmol/l) at rest to 2622(1486) pg/ml during exercise (155(88) nmol/l). Captopril favourably alters systemic vascular resistance and cardiac index during exercise in patients with congestive heart failure. This may reflect inhibition of the increased activity of the renin-angiotensin system during exercise in these patients and a subsequent reduction in systemic vasoconstriction.
Randomized trials in coronary bypass surgery.
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Osteoporosis and mastocytosis with late appearance of urticaria pigmentosa.
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Current management of leg ulcers.
Leg ulceration is a common disease which is developed countries is age-related and a consequence of venous hypertension. Therapy should be founded on elevation of the leg and on exercise. Drug therapy is aimed at promoting granulation tissue and epithelialisation. However, the ulcer bed and surrounding skin is vulnerable and the clinician's first objective is to do no harm. The choice of a drug should therefore take into account its possible side effects.
Determinants of operative mortality and long-term survival in patients with unstable angina. The CASS experience.
To identify the factors that determine operative mortality and long-term survival, we analyzed the data from 3,311 patients who underwent surgical therapy for unstable angina according to clinical presentation. Overall operative mortality was 3.9% and no differences in operative mortality were found between patients with coronary insufficiency, new-onset angina, rest angina, or changing patterns of angina. Logistic regression analysis indicated that age, left ventricular score, and presence of a left main stenosis in a left dominant circulation were related to operative mortality. The 7 year cumulative survival rate was 79%. Features predictive of long-term outcome by Cox analysis included left ventricular score, congestive heart failure score, other illness, extent of coronary disease, and cardiomegaly. Operative mortality of those patients who underwent coronary bypass during their initial hospitalization with unstable angina was similar to that of patients who were discharged and readmitted for operation at a later date. Thus, patients with unstable angina demonstrate a relatively low operative mortality, which is unrelated to the clinical presentation. Long-term survival is primarily determined by clinical and angiographic markers of left ventricular dysfunction, associated illness, and the extent of coronary disease.
Exercise testing in the Coronary Artery Surgery Study randomized population.
Exercise electrocardiographic stress testing was performed in 81% of the 780 patients randomized in the Coronary Artery Surgery Study at entry. The cumulative survival at the end of 7 year follow-up was 90% for those assigned to surgical treatment and 88% for those assigned to medical therapy (p = NS). These survival rates did not differ significantly from either those of the entire randomized cohort or those of the 149 patients who did not have a qualifying exercise test at baseline. No differences in important baseline characteristics existed between those who were exercised and not exercised at entry. Stratification of patients according to the degree of ST segment depression (less than 1 mm, greater than or equal to 1 mm, greater than 2 mm) and final exercise stage achieved during a Bruce protocol treadmill test (final stage less than or equal to 1, stage 2 and greater than or equal to stage 3) failed to show any significant differences in 7 year survival rates between medically and surgically assigned patients. Additionally no differences in survival were noted within either the medical or surgical groups regardless of the degree of ST segment depression or the final stage achieved. The presence of exercise-induced angina, however, identified patients who had a survival advantage if assigned to surgical therapy, with a 7 year survival rate of 94% compared with 87% for medically assigned patients (p = .007).(ABSTRACT TRUNCATED AT 250 WORDS)